Biventricular Versus Right Ventricular Pacing in Heart Failure Patients With Atrioventricular Block (BLOCK HF) (BLOCK HF)
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Study Type:  Interventional 

Study Design:  Allocation: Randomized; Intervention Model: Parallel Assignment; Masking: Double Blind (Subject, Outcomes Assessor); Primary Purpose: Treatment 
Conditions: 
Atrioventricular Block Heart Diseases 
Intervention: 
Device: Cardiac Resynchronization Therapy (CRT) 
Participant Flow
Recruitment Details
Key information relevant to the recruitment process for the overall study, such as dates of the recruitment period and locations 

No text entered. 
PreAssignment Details
Significant events and approaches for the overall study following participant enrollment, but prior to group assignment 

No text entered. 
Reporting Groups
Description  

No Implant Attempt  Subjects who did not undergo an implant attempt of a CRTP or CRTD device and were not randomized 
Unsuccessful Implants  Subjects who underwent an implant attempt of a CRTP or CRTD device but were not successfully implanted 
CRTP: Biventricular Pacing Arm  Subjects who were implanted with a CRTP device and randomized to receive biventricular pacing 
CRTP: Right Ventricular Pacing Arm  Subjects who were implanted with a CRTP device and randomized to receive right ventricular pacing 
CRTP: Not Randomized  Subjects successfully implanted with a CRTP device who were not randomized 
CRTD: Biventricular Pacing Arm  Subjects implanted with a CRTD device and randomized to receive biventricular pacing 
CRTD: Right Ventricular Pacing Arm  Subjects implanted with a CRTD device and randomized to receive right ventricular pacing. 
CRTD: Not Randomized  Subjects successfully implanted with a CRTD device who were not randomized 
Participant Flow: Overall Study
No Implant Attempt  Unsuccessful Implants  CRTP: Biventricular Pacing Arm  CRTP: Right Ventricular Pacing Arm  CRTP: Not Randomized  CRTD: Biventricular Pacing Arm  CRTD: Right Ventricular Pacing Arm  CRTD: Not Randomized  

STARTED  109  51  243  241  47  106  101  20 
COMPLETED  0  0  149  135  10  66  55  5 
NOT COMPLETED  109  51  94  106  37  40  46  15 
Death  0  0  57  66  14  23  28  9 
Lost to Followup  0  0  6  5  2  3  1  1 
Withdrawal by Subject  8  0  24  21  12  9  12  5 
Physician Decision  5  0  7  11  5  4  3  0 
Inclusion/Exclusion Criteria Not Met  96  0  0  0  2  0  0  0 
Unsuccessful Implant Exit Per Protocol  0  51  0  0  0  0  0  0 
Site closure  0  0  0  1  0  1  1  0 
Explanted Medtronic device  0  0  0  1  0  0  0  0 
NonMedtronic LV Lead Implanted  0  0  0  0  2  0  0  0 
Subject listed for heart transplant  0  0  0  0  0  0  1  0 
Sponsor withdrew subject  0  0  0  1  0  0  0  0 
Baseline Characteristics
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

No Implant Attempt  Subjects who did not undergo an implant attempt of a CRTP or CRTD device and were not randomized 
Unsuccessful Implants  Subjects who underwent an implant attempt of a CRTP or CRTD device but were not successfully implanted 
CRTP: Biventricular Pacing Arm  Subjects who were implanted with a CRTP device and randomized to receive biventricular pacing 
CRTP: Right Ventricular Pacing Arm  Subjects who were implanted with a CRTP device and randomized to receive right ventricular pacing 
CRTP: Not Randomized  Subjects successfully implanted with a CRTP device who were not randomized 
CRTD: Biventricular Pacing Arm  Subjects implanted with a CRTD device and randomized to receive biventricular pacing 
CRTD: Right Ventricular Pacing Arm  Subjects implanted with a CRTD device and randomized to receive right ventricular pacing. 
CRTD: Not Randomized  Subjects successfully implanted with a CRTD device who were not randomized 
Total  Total of all reporting groups 
Baseline Measures
No Implant Attempt  Unsuccessful Implants  CRTP: Biventricular Pacing Arm  CRTP: Right Ventricular Pacing Arm  CRTP: Not Randomized  CRTD: Biventricular Pacing Arm  CRTD: Right Ventricular Pacing Arm  CRTD: Not Randomized  Total  

Overall Participants Analyzed [Units: Participants] 
109  51  243  241  47  106  101  20  918  
Age [Units: Years] Mean (Standard Deviation) 
70.2 (12.6)  71.1 (11.2)  74.4 (10.2)  73.8 (10.8)  79.3 (7.6)  72.0 (9.3)  71.0 (10.0)  74.0 (9.1)  73.2 (10.6)  
Gender [Units: Participants] 

Female  29  14  62  73  18  19  20  4  239  
Male  80  37  181  168  29  87  81  16  679  
Race/Ethnicity, Customized [Units: Participants] 

Subject did not offer ethnicity  6  2  6  5  1  4  3  0  27  
African American  10  3  8  10  0  4  4  1  40  
Asian  0  0  0  0  1  0  0  0  1  
Caucasian  91  45  225  224  43  96  90  18  832  
Hispanic  1  0  3  1  2  2  2  1  12  
Native American  0  0  0  1  0  0  0  0  1  
Other  1  1  1  0  0  0  2  0  5  
Region of Enrollment [Units: Participants] 

United States  109  46  232  231  47  104  98  19  886  
Canada  0  5  11  10  0  2  3  1  32  
Outcome Measures
1. Primary:  Mortality, Heart Failurerelated Urgent Care Visits, or Significant Increase in Left Ventricular End Systolic Volume Index (LVESVI) [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months postrandomization. ] 
Measure Type  Primary 

Measure Title  Mortality, Heart Failurerelated Urgent Care Visits, or Significant Increase in Left Ventricular End Systolic Volume Index (LVESVI) 
Measure Description  Events include allcause mortality, heart failure(HF)related urgent care (a healthcare utilization visit involving intravenous(IV) therapy for heart failure) or significant increase(at least 15%) in LVESVI (a measure of the volume of a patient's left ventricle) from randomization to a later time point. Time from randomization until the subject experienced one of these events served as the outcome measure. LVESVI endpoints occurred primarily at those visits in which LVESVI measurements were required (6, 12, 18, 24 months). Because endpoints such as death or HF urgent care could occur at any time during followup, the subject's outcome measure could range from less than 1 month to 105 months (maximum followup duration). Primary endpoints and followup data occurring after a subject missed a required LVESVI measurement were excluded from the analysis and the table below. The counts reflect the number of subjects meeting each endpoint, and are not necessarily mutually exclusive. 
Time Frame  Participants were followed for the duration of the study, an average of 39.8 months postrandomization. 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

Only randomized subjects in both device groups were included in the analysis of this endpoint, as the analysis was restricted to postrandomization data. Subjects in the "No Implant Attempt", "Unsuccessful Implants", "CRTP: Not Randomized", and "CRTD: Not Randomized" subgroups were excluded. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
349  342 
Mortality, Heart Failurerelated Urgent Care Visits, or Significant Increase in Left Ventricular End Systolic Volume Index (LVESVI) [Units: Participants] 

Subjects Experiencing a Primary Endpoint  160  191 
Subjects with an LVESVI Primary Endpoint  93  136 
Subjects with an HF Urgent Care Primary Endpoint  70  94 
Subjects who died  55  66 
Statistical Analysis 1 for Mortality, Heart Failurerelated Urgent Care Visits, or Significant Increase in Left Ventricular End Systolic Volume Index (LVESVI)
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for HR 
P Value ^{[4]}  0.9990 
Hazard Ratio (HR) ^{[5]}  0.729 
95% Confidence Interval  0.592 to 0.889 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same rate of mortality, a heart failure urgent care visit, or significant increase in LVESVI as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with BiV pacing have a lower rate of this composite endpoint than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The posterior distribution is the set of values the BiV to RV hazard ratio can take, and its likelihood of taking such values.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study;a pvalue was not used. Instead, a posterior probability,representing the probability that patients with BiV pacing have lower risk of events than those with RV pacing, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
The hazard ratio corresponds to the time until death, a HF urgent care event or visit in which the LVESVI endpoint was met. Data beyond missed LVESVI measurements were excluded. A 95% credible interval was used instead of a 95% confidence interval. 
2. Secondary:  AllCause Mortality [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months postrandomization. ] 
Measure Type  Secondary 

Measure Title  AllCause Mortality 
Measure Description 
The endpoint is the time to death from any cause. The rate of mortality, as measure by the hazard rate, in each randomization arm will be compared. This outcome includes all postrandomization deaths, whereas the reporting of the primary outcome excluded primary endpoints (including deaths) that occurred after the subject had missed a studyrequired echocardiogram (used to determine if the LVESVI primary endpoint was met). 
Time Frame  Participants were followed for the duration of the study, an average of 39.8 months postrandomization. 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

Only randomized subjects in both device groups were included in the analysis of this endpoint, as the analysis was restricted to postrandomization data. Subjects in the "No Implant Attempt", "Unsuccessful Implants", "CRTP: Not Randomized", and "CRTD: Not Randomized" subgroups were excluded. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
349  342 
AllCause Mortality [Units: Participants] 

Subjects who died  80  94 
Subjects who did not die  269  248 
Statistical Analysis 1 for AllCause Mortality
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for HR 
P Value ^{[4]}  0.865 
Hazard Ratio (HR) ^{[5]}  0.843 
95% Confidence Interval  0.632 to 1.142 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same rate of mortality as corresponding patients who receive right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The posterior distribution is the set of values the BiV to RV hazard ratio for death can take, and its likelihood of taking such values.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; thus pvalues were not used. Instead, posterior probabilities, representing the probability that subjects with biventricular pacing have better outcomes, were calculated. A probability ≥ 0.95 was significant.  
[5]  Other relevant estimation information: 
Because BLOCK HF was a Bayesian study, a 95% credible interval was used in lieu of a 95% confidence interval. This interval reflects the set of values the Hazard Ratio can take with 95% posterior probability. 
3. Secondary:  AllCause Mortality or Heart Failurerelated Hospitalization [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months postrandomization. ] 
Measure Type  Secondary 

Measure Title  AllCause Mortality or Heart Failurerelated Hospitalization 
Measure Description  The endpoint will be a subject's time from randomization to either their first heart failurerelated hospitalization, or death. 
Time Frame  Participants were followed for the duration of the study, an average of 39.8 months postrandomization. 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

Only randomized subjects in both device groups were included in the analysis of this endpoint, as the analysis was restricted to postrandomization data. Subjects in the "No Implant Attempt", "Unsuccessful Implants", "CRTP: Not Randomized", and "CRTD: Not Randomized" subgroups were excluded. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
349  342 
AllCause Mortality or Heart Failurerelated Hospitalization [Units: Participants] 

Subjects who died or underwent HF hospitalization  121  135 
Subjects who died  80  94 
Subjects who underwent HF hospitalization  79  92 
Statistical Analysis 1 for AllCause Mortality or Heart Failurerelated Hospitalization
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for HR 
P Value ^{[4]}  0.9785 
Hazard Ratio (HR) ^{[5]}  0.781 
95% Confidence Interval  0.615 to 0.991 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same rate of mortality or heart failure(HF)related hospitalization as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a lower rate of death or first HF hospitalization than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The posterior distribution is the set of values the BiV to RV hazard ratio can take, and its likelihood of taking such values.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; a pvalue was not used. Instead, a posterior probability, representing the probability that patients with BiV pacing have better outcomes than those with RV pacing, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
Because BLOCK HF was a Bayesian study, a 95% credible interval was used in lieu of a 95% confidence interval. This interval reflects the set of values the Hazard Ratio can take with 95% posterior probability. 
4. Secondary:  AllCause Mortality or Significant Increase in Left Ventricular End Systolic Volume Index [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months postrandomization. ] 
Measure Type  Secondary 

Measure Title  AllCause Mortality or Significant Increase in Left Ventricular End Systolic Volume Index 
Measure Description 
The endpoint will be the time from randomization to either death or a visit (6, 12, 18, 24 month or interim visit) in which the subject undergoes an echocardiogram and the measured left ventricular end systolic volume index (a measure of the size of the subject's left ventricle normalized over their body surface area) is at least 15% greater than the corresponding measured value at randomization. Only LVESVI endpoints/deaths and followup data occurring before a subject missed an LVESVI measurement (due to missed visit, echo not performed, etc.) were used in the analysis and included in the table below. The counts reflect the number of subjects meeting each endpoint, and are not mutually exclusive. 
Time Frame  Participants were followed for the duration of the study, an average of 39.8 months postrandomization. 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

Only randomized subjects in both device groups were included in the analysis of this endpoint, as the analysis was restricted to postrandomization data. Subjects in the "No Implant Attempt", "Unsuccessful Implants", "CRTP: Not Randomized", and "CRTD: Not Randomized" subgroups were excluded. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
349  342 
AllCause Mortality or Significant Increase in Left Ventricular End Systolic Volume Index [Units: Participants] 

Subjects who died or experienced LVESVI event  131  171 
Subjects who died  55  66 
Subjects who experienced LVESVI event  93  136 
Statistical Analysis 1 for AllCause Mortality or Significant Increase in Left Ventricular End Systolic Volume Index
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for HR 
P Value ^{[4]}  0.9886 
Hazard Ratio (HR) ^{[5]}  0.695 
95% Confidence Interval  0.558 to 0.866 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or II who receive biventricular pacing have the same rate of mortality or significant increase in LVESVI as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a lower rate of death or significant increase in LVESVI than patients with right ventricular pacing. 

[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The posterior distribution is the set of values the BiV to RV hazard ratio can take, and its likelihood of taking such values.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; a pvalue was not used. Instead, a posterior probability, representing the probability that patients with BiV pacing have better outcomes than those with RV pacing, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
The hazard ratio corresponds to the time from randomization to death or a visit in which LVESVI endpoint was met. Data beyond missed LVESVI measurements were excluded. A 95% credible interval was used instead of a 95% confidence interval. 
5. Secondary:  First Heart Failure Hospitalization [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months postrandomization. ] 
Measure Type  Secondary 

Measure Title  First Heart Failure Hospitalization 
Measure Description  The endpoint is the time from randomization to a subject's first heart failure (HF)related hospitalization. For each randomization arm, the number of subjects who met the endpoint, experiencing at least one heart failurerelated hospitalization postrandomization, are reported, as well as the number of randomized subjects who did not experience any HF hospitalizations postrandomization. 
Time Frame  Participants were followed for the duration of the study, an average of 39.8 months postrandomization. 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

Only randomized subjects in both device groups were included in the analysis of this endpoint, as the analysis was restricted to postrandomization data. Subjects in the "No Implant Attempt", "Unsuccessful Implants", "CRTP: Not Randomized", and "CRTD: Not Randomized" subgroups were excluded. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
349  342 
First Heart Failure Hospitalization [Units: Participants] 

Subjects experiencing a HF hospitalization  79  92 
Subjects not experiencing a HF hospitalization  270  250 
Statistical Analysis 1 for First Heart Failure Hospitalization
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for HR 
P Value ^{[4]}  0.9904 
Hazard Ratio (HR) ^{[5]}  0.704 
95% Confidence Interval  0.522 to 0.947 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same rate of first heart failure(HF)related hospitalization as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a lower rate of first HF hospitalization than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The posterior distribution is the set of values the BiV to RV hazard ratio can take, and its likelihood of taking such values.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; a pvalue was not used. Instead, a posterior probability, representing the probability that patients with BiV pacing have better outcomes than those with RV pacing, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
Because BLOCK HF was a Bayesian study, a 95% credible interval was used in lieu of a 95% confidence interval. This interval reflects the set of values the Hazard Ratio can take with 95% posterior probability. 
6. Secondary:  Days Hospitalized for Heart Failure [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months postrandomization. ] 
Measure Type  Secondary 

Measure Title  Days Hospitalized for Heart Failure 
Measure Description  For each subject the endpoint was the days hospitalized for heart failure per patient year, calculated as the total number of days the subject was hospitalized for heart failure divided by the subject's total followup time. Only postrandomization data were used. 
Time Frame  Participants were followed for the duration of the study, an average of 39.8 months postrandomization. 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

Only randomized subjects in both device groups were included in the analysis of this endpoint, as the analysis was restricted to postrandomization data. Subjects in the "No Implant Attempt", "Unsuccessful Implants", "CRTP: Not Randomized", and "CRTD: Not Randomized" subgroups were excluded. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
349  342 
Days Hospitalized for Heart Failure [Units: Days hospitalized per patient year] Mean (Standard Deviation) 
1.89 (9.52)  2.63 (16.08) 
Statistical Analysis 1 for Days Hospitalized for Heart Failure
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Difference in Average Ranks 
P Value ^{[4]}  0.637 
BiV  RV Difference in Average Rank ^{[5]}  1.8 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same rate of days hospitalized for heart failure per year as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a lower rate of days hospitalized for HF than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The subjects' individual rates of days hospitalized for HF were ranked, with lower ranks corresponding to fewer days hospitalized for HF.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; a pvalue was not used. Instead, a posterior probability, representing the probability that patients with BiV pacing have better outcomes than those with RV pacing, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
The posterior probability that the BiV  RV difference in average ranks was below 0 (denoting that the BiV arm had lower ranks than the RV arm, on average) was calculated. 
7. Secondary:  Change in New York Heart Association Classification [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in New York Heart Association Classification 
Measure Description  The endpoint is a subject's change in New York Heart Association Classification (a measure of the degree of heart failure a subject has on a 4 class scale, with NYHA I being the healthiest score and NYHA IV being the sickest score) from randomization to each of four time points: 6 months, 12 months, 18 months, and 24 months postrandomization. The change categories listed will be relative to randomization. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

For each time point(e.g. 6 months), only subjects with NYHA assessed at both randomization and that time point were included in the analysis. Those who could not be analyzed at a time point(for reasons such as death, exit,missed visit,or NYHA not assessed at visit) are listed under the "Comparative data not available" category for that time point. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
349  342 
Change in New York Heart Association Classification [Units: Participants] 

6 Months: Improved by 2 classes from randomization  5  3 
6 Months: Improved by 1 class from randomization  54  43 
6 Months: No change from randomization  200  205 
6 Months: Worsened by 1 class from randomization  52  41 
6 Months: Worsened by 2 classes from randomization  1  1 
6 Months: Comparative data not available  37  49 
12 Months:Improved by 2 classes from randomization  4  5 
12 Months:Improved by 1 class from randomization  54  34 
12 Months: No change from randomization  172  172 
12 Months: Worsened by 1 class from randomization  49  64 
12 Months:Worsened by 2 classes from randomization  2  3 
12 Months: Comparative data not available  68  64 
18 Months:Improved by 2 classes from randomization  3  2 
18 Months: Improved by 1 class from randomization  43  45 
18 Months: No change from randomization  142  141 
18 Months: Worsened by 1 class from randomization  50  56 
18 Months:Worsened by 2 classes from randomization  4  6 
18 Months: Comparative data not available  107  92 
24 Months:Improved by 2 classes from randomization  2  3 
24 Months: Improved by 1 class from randomization  35  36 
24 Months: No change from randomization  135  126 
24 Months:Worsened by 1 class from randomization  41  54 
24 Months:Worsened by 2 classes from randomization  4  3 
24 Months: Comparative data not available  132  120 
Statistical Analysis 1 for Change in New York Heart Association Classification
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for Average Rank 
P Value ^{[4]}  0.591 
BiV  RV Difference in Average Rank ^{[5]}  0.012 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

Subjects' changes in NYHA classification from randomization to 6 months were determined. The null hypothesis was that the average change among patients with biventricular pacing is equal to that of patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
Subjects' Randomization  6 month changes in NYHA classification were ranked. The BiV  RV difference in average rank was analyzed.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; thus pvalues were not used. Instead, a posterior probability, representing the probability that subjects with biventricular pacing have better outcomes at 6 months, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
Positive values reflect better outcomes over time in the BiV arm than the RV arm. 
Statistical Analysis 2 for Change in New York Heart Association Classification
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for Average Rank 
P Value ^{[4]}  0.986 
BiV  RV Difference in Average Rank ^{[5]}  0.126 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

Subjects' changes in NYHA classification from randomization to 12 months were determined. The null hypothesis was that the average change among patients with biventricular pacing is equal to that of patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
Subjects' Randomization  12 month changes in NYHA classification were ranked. The BiV  RV difference in average rank was analyzed.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; thus pvalues were not used. Instead, a posterior probability,representing the probability that subjects with biventricular pacing have better outcomes at 12 months, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
Positive values reflect better outcomes over time in the BiV arm than the RV arm. 
Statistical Analysis 3 for Change in New York Heart Association Classification
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for Average Rank 
P Value ^{[4]}  0.726 
BiV  RV Difference in Average Rank ^{[5]}  0.039 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

Subjects' changes in NYHA classification from randomization to 18 months were determined. The null hypothesis was that the average change among patients with biventricular pacing is equal to that of patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
Subjects' Randomization  18 month changes in NYHA classification were ranked. The BiV  RV difference in average rank was analyzed.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; thus pvalues were not used. Instead, a posterior probability,representing the probability that subjects with biventricular pacing have better outcomes at 12 months, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
Positive values reflect better outcomes over time in the BiV arm than the RV arm. 
Statistical Analysis 4 for Change in New York Heart Association Classification
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for Average Rank 
P Value ^{[4]}  0.701 
BiV  RV Difference in Average Rank ^{[5]}  0.035 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

Subjects' changes in NYHA classification from randomization to 24 months were determined. The null hypothesis was that the average change among patients with biventricular pacing is equal to that of patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
Subjects' Randomization  24 month changes in NYHA classification were ranked. The BiV  RV difference in average rank was analyzed.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; thus pvalues were not used. Instead, a posterior probability,representing the probability that subjects with biventricular pacing have better outcomes at 24 months, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
Positive values reflect better outcomes over time in the BiV arm than the RV arm. 
8. Secondary:  Change in Heart Failure Stage [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Heart Failure Stage 
Measure Description  The endpoint is a subject's change in Heart Failure Stage (a measure of the degree of heart failure a subject has on a 4 stage scale (A, B, C, D), with Class A being the healthiest score and Class D being the sickest score) from randomization to each of four time points: 6 months, 12 months, 18 months, and 24 months. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

For each time point(e.g. 6 months), only subjects with HF Stage assessed at randomization and that time point were included in the analysis. Those who could not be analyzed at a time point(for reasons such as death, exit,missed visit,or HF Stage not assessed) are listed under the "Comparative data not available" category for that time point. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
349  342 
Change in Heart Failure Stage [Units: Participants] 

6 Months: Improved by 2 stages since randomization  1  0 
6 Months: Improved by 1 stage since randomization  11  5 
6 Months: No change from randomization  296  274 
6 Months: Worsened by 1 stage since randomization  2  14 
6 Months: Worsened by 2 stages since randomization  1  0 
6 Months: Comparative data not available  38  49 
12 Months:Improved by 2 stages since randomization  0  0 
12 Months:Improved by 1 stage since randomization  7  8 
12 Months: No change since randomization  258  244 
12 Months: Worsened by 1 stage since randomization  15  23 
12 Months:Worsened by 2 stages since randomization  1  1 
12 Months: Comparative data not available  68  66 
18 Months:Improved by 2 stages since randomization  0  0 
18 Months:Improved by 1 stage since randomization  4  5 
18 Months: No change since randomization  222  225 
18 Months:Worsened by 1 stage since randomization  16  18 
18 Months:Worsened by 2 stages since randomization  0  1 
18 Months: Comparative data not available  107  93 
24 Months:Improved by 2 stages since randomization  0  0 
24 Months: Improved by 1 stage since randomization  4  6 
24 Months: No change since randomization  196  197 
24 Months:Worsened by 1 stage since randomization  16  19 
24 Months:Worsened by 2 stages since randomization  1  0 
24 Months: Comparative data not available  132  120 
Statistical Analysis 1 for Change in Heart Failure Stage
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for Average Rank 
P Value ^{[4]}  0.534 
BiV  RV Difference in Average Rank ^{[5]}  0.002 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

Subjects' changes in HF stage from randomization to 6 months were determined. The null hypothesis was that the average change among patients with biventricular pacing is equal to that of patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
Subjects' Randomization  6 month change in HF Stage were ranked. The BiV  RV difference in average rank was analyzed.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; thus pvalues were not used. Instead, a posterior probability, representing the probability that subjects with biventricular pacing have better outcomes at 6 months, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
Positive values reflect better outcomes over time in the BiV arm than the RV arm. 
Statistical Analysis 2 for Change in Heart Failure Stage
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for Average Rank 
P Value ^{[4]}  0.825 
BiV  RV Difference in Average Rank ^{[5]}  0.026 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

Subjects' change in HF stage from randomization to 12 months were determined. The null hypothesis was that the average change among patients with biventricular pacing is equal to that of patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
Subjects' Randomization  12 month changes in HF Stage were ranked. The BiV  RV difference in average rank was analyzed.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; thus pvalues were not used. Instead, a posterior probability,representing the probability that subjects with biventricular pacing have better outcomes at 12 months, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
Positive values reflect better outcomes over time in the BiV arm than the RV arm. 
Statistical Analysis 3 for Change in Heart Failure Stage
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for Average Rank 
P Value ^{[4]}  0.651 
BiV  RV Difference in Average Rank ^{[5]}  0.010 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

Subjects' changes in HF stage from randomization to 18 months were determined. The null hypothesis was that the average change among patients with biventricular pacing is equal to that of patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
Subjects' Randomization  18 month changes in HF Stage were ranked. The BiV  RV difference in average rank was analyzed.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; thus pvalues were not used. Instead, a posterior probability,representing the probability that subjects with biventricular pacing have better outcomes at 18 months, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
Positive values denote that the BiV arm had better outcomes over time than the RV arm. 
Statistical Analysis 4 for Change in Heart Failure Stage
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Distribution for Average Rank 
P Value ^{[4]}  0.425 
BiV  RV Difference in Average Rank ^{[5]}  0.006 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

Subjects' changes in HF stage from randomization to 24 months were determined. The null hypothesis was that the average change among patients with biventricular pacing is equal to that of patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
Subjects' Randomization  24 month changes in HF Stage were ranked. The BiV  RV difference in average rank was analyzed.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; thus pvalues were not used. Instead, a posterior probability,representing the probability that subjects with biventricular pacing have better outcomes at 24 months, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
Positive values denote better outcomes over time in the BiV arm than the RV arm. 
9. Secondary:  Change in Cardiovascular Medications [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months postrandomization. ] 
Measure Type  Secondary 

Measure Title  Change in Cardiovascular Medications 
Measure Description  The endpoints are what classes of drugs (e.g. Beta blockers, Diuretics, Nitrates, etc.) each subject was on at the time of scheduled visits (e.g Randomization, 6 months, 12 months, etc.) 
Time Frame  Participants were followed for the duration of the study, an average of 39.8 months postrandomization. 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

Because indications for defibrillation devices like CRTDs are defined by characteristics that relate to medication guidelines, medication results are presented separately for each device group. Medications were assessed only for subjects who completed visits (denoted as "Subjects with Medications Assessed"). 
Reporting Groups
Description  

CRTP: Biventricular Pacing Arm  Subjects implanted with a CRTP device and randomized to receive biventricular pacing 
CRTP: Right Ventricular Pacing Arm  Subjects implanted with a CRTD device and randomized to receive right ventricular pacing. 
CRTD: Biventricular Pacing Arm  Subjects implanted with a CRTD device and randomized to receive biventricular pacing 
CRTD: Right Ventricular Pacing Arm  Subjects implanted with a CRTD device and randomized to receive right ventricular pacing 
Measured Values
CRTP: Biventricular Pacing Arm  CRTP: Right Ventricular Pacing Arm  CRTD: Biventricular Pacing Arm  CRTD: Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
243  241  106  101 
Change in Cardiovascular Medications [Units: Participants] 

Randomization: Subjects on ACEInhibitors/ARBs  173  179  93  84 
Randomization: Subjects on Beta Blockers  186  191  98  93 
Randomization: Subjects on Vasodilators/Nitrates  53  44  31  20 
Randomization: Subjects on Aldosterone Antagonists  33  25  19  25 
Randomization: Subjects on Diuretics  156  158  74  74 
6 Months: Subjects with Medications Assessed  226  207  94  89 
6 Months: Subjects on ACEInhibitors/ARBs  162  152  77  73 
6 Months: Subjects on Beta Blockers  175  171  87  79 
6 Months: Subjects on Vasodilators/Nitrates  46  42  24  12 
6 Months: Subjects on Aldosterone Antagonists  31  21  20  25 
6 Months: Subjects on Diuretics  148  137  66  70 
12 Months: Subjects with Medications Assessed  205  200  83  81 
12 Months: Subjects on ACEInhibitors/ARBs  147  151  72  70 
12 Months: Subjects on Beta Blockers  158  170  79  75 
12 Months: Subjects on Vasodilators/Nitrates  45  43  22  13 
12 Months: Subjects on Aldosterone Antagonists  23  20  13  21 
12 Months: Subjects on Diuretics  133  131  57  60 
18 Months: Subjects with Medications Assessed  169  181  78  72 
18 Months: Subjects on ACEInhibitors/ARBs  121  137  62  58 
18 Months: Subjects on Beta Blockers  134  152  75  63 
18 Months: Subjects on Vasodilators/Nitrates  36  44  22  11 
18 Months: Subjects on Aldosterone Antagonists  16  21  9  20 
18 Months: Subjects on Diuretics  111  125  51  59 
24 Months: Subjects with Medications Assessed  152  157  69  67 
24 Months: Subjects on ACEInhibitors/ARBs  114  119  58  56 
24 Months: Subjects on Beta Blockers  118  133  65  63 
24 Months: Subjects on Vasodilators/Nitrates  28  37  23  10 
24 Months: Subjects on Aldosterone Antagonists  18  15  13  18 
24 Months: Subjects on Diuretics  97  104  47  56 
30 Months: Subjects with Medications Assessed  130  131  53  57 
30 Months: Subjects on ACEInhibitors/ARBs  92  102  42  47 
30 Months: Subjects on Beta Blockers  104  114  51  56 
30 Months: Subjects on Vasodilators/Nitrates  23  28  16  11 
30 Months: Subjects on Aldosterone Antagonists  14  14  10  15 
30 Months: Subjects on Diuretics  82  90  36  50 
36 Months: Subjects with Medications Assessed  109  112  42  44 
36 Months: Subjects on ACEInhibitors/ARBs  76  85  30  37 
36 Months: Subjects on Beta Blockers  86  97  41  44 
36 Months: Subjects on Vasodilators/Nitrates  21  24  14  9 
36 Months: Subjects on Aldosterone Antagonists  10  19  8  10 
36 Months: Subjects on Diuretics  69  79  34  37 
42 Months: Subjects with Medications Assessed  94  99  38  42 
42 Months: Subjects on ACEInhibitors/ARBs  69  73  27  35 
42 Months: Subjects on Beta Blockers  75  86  35  42 
42 Months: Subjects on Vasodilators/Nitrates  15  22  12  10 
42 Months: Subjects on Aldosterone Antagonists  8  13  9  12 
42 Months: Subjects on Diuretics  57  71  31  39 
No statistical analysis provided for Change in Cardiovascular Medications
10. Secondary:  Frequency of Adverse Events Postrandomization [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months postrandomization. ] 
Measure Type  Secondary 

Measure Title  Frequency of Adverse Events Postrandomization 
Measure Description  Adverse events that subjects experienced after they were randomized were compared between arms with regard to several categories such as heart failure (HF)relatedness, relatedness to the implant procedure, and relatedness to the implanted system, including individual components such as the left ventricular (LV) lead and the CRTP or CRTD generator. 
Time Frame  Participants were followed for the duration of the study, an average of 39.8 months postrandomization. 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

CRTP: Biventricular Pacing Arm  Subjects implanted with a CRTP device and randomized to receive biventricular pacing 
CRTP: Right Ventricular Pacing Arm  Subjects implanted with a CRTD device and randomized to receive right ventricular pacing. 
CRTD: Biventricular Pacing Arm  Subjects implanted with a CRTD device and randomized to receive biventricular pacing 
CRTD: Right Ventricular Pacing Arm  Subjects implanted with a CRTD device and randomized to receive right ventricular pacing 
Measured Values
CRTP: Biventricular Pacing Arm  CRTP: Right Ventricular Pacing Arm  CRTD: Biventricular Pacing Arm  CRTD: Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
243  241  106  101 
Frequency of Adverse Events Postrandomization [Units: Participants] 

Subjects with procedurerelated AE(s)  37  7  7  2 
Subjects with systemrelated AE(s)  56  31  47  24 
Subjects with LV leadrelated AE(s)  40  12  14  4 
Subjects with CRTP/CRTD related AE(s)  12  17  36  18 
Subjects with HFrelated AE(s)  73  106  45  47 
No statistical analysis provided for Frequency of Adverse Events Postrandomization
11. Secondary:  Cardiovascularrelated Healthcare Utilizations [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months postrandomization. ] 
Measure Type  Secondary 

Measure Title  Cardiovascularrelated Healthcare Utilizations 
Measure Description  Cardiovascularrelated healthcare utilizations (HCUs), such as hospitalizations, Emergency Department visits, urgent care visits, and clinic visits that subjects experienced after being randomized were summarized for each randomization arm 
Time Frame  Participants were followed for the duration of the study, an average of 39.8 months postrandomization. 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
349  342 
Cardiovascularrelated Healthcare Utilizations [Units: Participants] 

Subjects with a postrandomization CV HCU  264  263 
Subjects with postrandomization hospitalization  164  162 
Subjects with postrandomization ED visit  118  128 
Subjects with postrandomization urgent care visit  12  12 
Subjects with postrandomization clinic visit  214  220 
No statistical analysis provided for Cardiovascularrelated Healthcare Utilizations
12. Secondary:  Change in Quality of Life at 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in Quality of Life at 6 Months 
Measure Description 
The endpoint will be a subject's change in Quality of Life score from randomization to 6 months. The Quality of Life score at a time point is calculated using the Minnesota Living with Heart Failure Questionnaire, which consists of 21 questions each on a 6 point scale from 0 to 5. The 21 scores are added up and the final score, ranging from 0 (best) to 105 (worst) is the subject's quality of life score. For each subject the measure will be the randomization visit  6 month difference in QOL score, with positive values denoting a reduction in score and improvement in Quality of Life. Subjects with missing QOL scores at one or both time points were excluded from analysis, and so the number of subjects analyzed for this outcome was a subset of the number of randomized subjects. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
304  289 
Change in Quality of Life at 6 Months [Units: Units on a scale] Mean (Standard Deviation) 
5 (20.3)  0.3 (19.4) 
Statistical Analysis 1 for Change in Quality of Life at 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Probability of Mean QOL Change 
P Value ^{[4]}  0.9976 
Mean Difference (Final Values) ^{[5]}  4.7 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in QOL score from randomization to 6 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a greater reduction (and thus improvement) in QOL score at 6 months than patients with right ventricular pacing. 

[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The posterior distribution for the BiV  RV difference in mean QOL score improvement from randomization to 6 months was determined.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; a pvalue was not used. Instead, a posterior probability, representing the probability that patients with BiV pacing have better outcomes than those with RV pacing, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
No text entered. 
13. Secondary:  Change in Quality of Life at 12 Months [ Time Frame: Randomization to 12 months ] 
Measure Type  Secondary 

Measure Title  Change in Quality of Life at 12 Months 
Measure Description 
The endpoint will be a subject's change in Quality of Life score from randomization to 12 months. The Quality of Life score at a time point is calculated using the Minnesota Living with Heart Failure Questionnaire, which consists of 21 questions each on a 6 point scale from 0 to 5. The 21 scores are added up and the final score, ranging from 0 (best) to 105 (worst) is the subject's quality of life score. For each subject the measure will be the randomization visit  12 month difference in QOL score, with positive values denoting a reduction in score and improvement in Quality of Life. Subjects with missing QOL scores at one or both time points were excluded from analysis, and so the number of subjects analyzed for this outcome was a subset of the number of randomized subjects. 
Time Frame  Randomization to 12 months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
274  273 
Change in Quality of Life at 12 Months [Units: Units on a scale] Mean (Standard Deviation) 
3.9 (20.1)  0.9 (18.9) 
Statistical Analysis 1 for Change in Quality of Life at 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Probability of Mean QOL Change 
P Value ^{[4]}  0.9641 
Mean Difference (Final Values) ^{[5]}  3.0 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in QOL score from randomization to 12 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a greater reduction (and thus improvement) in QOL score at 12 months than patients with right ventricular pacing. 

[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The posterior distribution for the BiV  RV difference in mean QOL score improvement from randomization to 12 months was determined.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; a pvalue was not used. Instead, a posterior probability, representing the probability that patients with BiV pacing have better outcomes than those with RV pacing, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
No text entered. 
14. Secondary:  Change in Quality of Life at 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in Quality of Life at 18 Months 
Measure Description 
The endpoint will be a subject's change in Quality of Life score from randomization to 18 months. The Quality of Life score at a time point is calculated using the Minnesota Living with Heart Failure Questionnaire, which consists of 21 questions each on a 6 point scale from 0 to 5. The 21 scores are added up and the final score, ranging from 0 (best) to 105 (worst) is the subject's quality of life score. For each subject the measure will be the randomization visit  18 month difference in QOL score, with positive values denoting a reduction in score and improvement in Quality of Life. Subjects with missing QOL scores at one or both time points were excluded from analysis, and so the number of subjects analyzed for this outcome was a subset of the number of randomized subjects. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
237  244 
Change in Quality of Life at 18 Months [Units: Units on a scale] Mean (Standard Deviation) 
2.3 (20.5)  0.5 (18.1) 
Statistical Analysis 1 for Change in Quality of Life at 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Probability of Mean QOL Change 
P Value ^{[4]}  0.8416 
Mean Difference (Final Values) ^{[5]}  1.8 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in QOL score from randomization to 18 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a greater reduction (and thus improvement) in QOL score at 18 months than patients with right ventricular pacing. 

[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The parameter of interest was the BiV  RV difference in mean QOL change from randomization to 18 months.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; a pvalue was not used. Instead, a posterior probability, representing the probability that patients with BiV pacing have better outcomes than those with RV pacing, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
No text entered. 
15. Secondary:  Change in Quality of Life at 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Quality of Life at 24 Months 
Measure Description 
The endpoint will be a subject's change in Quality of Life score from randomization to 24 months. The Quality of Life score at a time point is calculated using the Minnesota Living with Heart Failure Questionnaire, which consists of 21 questions each on a 6 point scale from 0 to 5. The 21 scores are added up and the final score, ranging from 0 (best) to 105 (worst) is the subject's quality of life score. For each subject the measure will be the randomization visit  24 month difference in QOL score, with positive values denoting a reduction in score and improvement in Quality of Life. Subjects with missing QOL scores at one or both time points were excluded from analysis, and so the number of subjects analyzed for this outcome was a subset of the number of randomized subjects. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
214  218 
Change in Quality of Life at 24 Months [Units: Units on a scale] Mean (Standard Deviation) 
2.6 (20.5)  1.5 (18.8) 
Statistical Analysis 1 for Change in Quality of Life at 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior Probability of Mean QOL Change 
P Value ^{[4]}  0.7270 
Mean Difference (Final Values) ^{[5]}  1.1 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in QOL score from randomization to 24 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a greater reduction (and thus improvement) in QOL score at 24 months than patients with right ventricular pacing. 

[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The posterior distribution for the BiV  RV difference in mean QOL score improvement from randomization to 24 months was determined.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; a pvalue was not used. Instead, a posterior probability, representing the probability that patients with BiV pacing have better outcomes than those with RV pacing, was calculated. A probability ≥0.95 was significant.  
[5]  Other relevant estimation information: 
No text entered. 
16. Secondary:  Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 6 Months 
Measure Description  The endpoint will be a subject's change in LV Ejection Fraction (a measure of the percentage of blood ejected from the left ventricle of the heart with each contraction). A normal range is 55% to 70%. For each subject the measure will be the 6 month  randomization visit difference in LVEF value. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
282  273 
Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 6 Months [Units: Percentage] Mean (Standard Deviation) 
3.0 (8.4)  0.3 (8.9) 
Statistical Analysis 1 for Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  3.334 
95% Confidence Interval  1.886 to 4.815 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEF from randomization to 6 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVEF from randomization to 6 months than patients with right ventricular pacing. 

[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEF change through 6 months. 
17. Secondary:  Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 12 Months [ Time Frame: Randomization to 12 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 12 Months 
Measure Description  The endpoint will be a subject's change in LV Ejection Fraction (a measure of the percentage of blood ejected from the left ventricle of the heart with each contraction). A normal range is 55% to 70%. For each subject the measure will be the 12 month  randomization visit difference in LVEF value. 
Time Frame  Randomization to 12 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
263  260 
Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 12 Months [Units: Percentage] Mean (Standard Deviation) 
2.7 (9.3)  0.5 (9.4) 
Statistical Analysis 1 for Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  3.232 
95% Confidence Interval  1.618 to 4.839 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEF from randomization to 12 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVEF from randomization to 12 months than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEF change through 12 months. 
18. Secondary:  Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 18 Months 
Measure Description  The endpoint will be a subject's change in LV Ejection Fraction (a measure of the percentage of blood ejected from the left ventricle of the heart with each contraction). A normal range is 55% to 70%. For each subject the measure will be the 18 month  randomization visit difference in LVEF value. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
223  226 
Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 18 Months [Units: Percentage] Mean (Standard Deviation) 
2.7 (9.5)  0.4 (10.1) 
Statistical Analysis 1 for Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  2.240 
95% Confidence Interval  0.419 to 4.066 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEF from randomization to 18 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVEF from randomization to 18 months than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEF change through 18 months. 
19. Secondary:  Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 24 Months 
Measure Description  The endpoint will be a subject's change in LV Ejection Fraction (a measure of the percentage of blood ejected from the left ventricle of the heart with each contraction). A normal range is 55% to 70%. For each subject the measure will be the 24 month  randomization visit difference in LVEF value. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
192  205 
Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 24 Months [Units: Percentage] Mean (Standard Deviation) 
2.0 (9.6)  1.6 (10.5) 
Statistical Analysis 1 for Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  3.623 
95% Confidence Interval  1.623 to 5.604 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEF from randomization to 24 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVEF from randomization to 24 months than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEF change through 24 months. 
20. Secondary:  Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 6 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular End Systolic Volume Index (a measure of the volume of blood in the left ventricle at the end of systole, normalized over body surface area). In other words, a measure of the size of the left ventricle. For each subject the measure is the 6 month  randomization visit difference in LVESVI. Negative values correspond to reductions in LVESVI over time. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
279  272 
Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 6 Months [Units: Ml/square meter of body surface area] Mean (Standard Deviation) 
6.8 (17.1)  0.4 (17.7) 
Statistical Analysis 1 for Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  7.204 
95% Confidence Interval  10.12 to 4.214 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVESVI from randomization to 6 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVESVI from randomization to 6 months than patients with right ventricular pacing. 

[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVESVI change through 6 months. 
21. Secondary:  Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 12 Months [ Time Frame: Randomization to 12 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 12 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular End Systolic Volume Index (a measure of the volume of blood in the left ventricle at the end of systole, normalized over body surface area). In other words, a measure of the size of the left ventricle. For each subject the measure is the 12 month  randomization visit difference in LVESVI. Negative values correspond to reductions in LVESVI over time. 
Time Frame  Randomization to 12 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
260  256 
Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 12 Months [Units: Ml/square meter of body surface area] Mean (Standard Deviation) 
6.8 (18.7)  0.5 (20.2) 
Statistical Analysis 1 for Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  7.255 
95% Confidence Interval  10.590 to 3.829 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVESVI from randomization to 12 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVESVI from randomization to 12 months than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVESVI change through 12 months. 
22. Secondary:  Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 18 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular End Systolic Volume Index (a measure of the volume of blood in the left ventricle at the end of systole, normalized over body surface area). In other words, a measure of the size of the left ventricle. For each subject the measure is the 18 month  randomization visit difference in LVESVI. Negative values correspond to reductions in LVESVI over time. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
219  225 
Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 18 Months [Units: Ml/square meter of body surface area] Mean (Standard Deviation) 
8.8 (18.9)  0.5 (19.9) 
Statistical Analysis 1 for Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  8.242 
95% Confidence Interval  11.860 to 4.574 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVESVI from randomization to 18 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVESVI from randomization to 18 months than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVESVI change through 18 months. 
23. Secondary:  Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 24 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular End Systolic Volume Index (a measure of the volume of blood in the left ventricle at the end of systole, normalized over body surface area). In other words, a measure of the size of the left ventricle. For each subject the measure is the 24 month  randomization visit difference in LVESVI. Negative values correspond to reductions in LVESVI over time. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
187  204 
Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 24 Months [Units: Ml/square meter of body surface area] Mean (Standard Deviation) 
6.0 (22.6)  1.4 (21.3) 
Statistical Analysis 1 for Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  7.268 
95% Confidence Interval  11.690 to 2.846 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVESVI from randomization to 24 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVESVI from randomization to 24 months than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVESVI change through 24 months. 
24. Secondary:  Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 6 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular End Diastolic Volume Index (a measure of the volume of blood in the left ventricle at the end of diastole, normalized over body surface area). In other words, a measure of the size of the left ventricle. For each subject the measure is the 6 month  randomization visit difference in LVEDVI. Negative values correspond to reductions in LVEDVI over time. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
281  273 
Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 6 Months [Units: Ml/square meter of body surface area] Mean (Standard Deviation) 
6.2 (19.2)  0.3 (19.5) 
Statistical Analysis 1 for Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  5.858 
95% Confidence Interval  9.085 to 2.562 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEDVI from randomization to 6 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVEDVI from randomization to 6 months than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEDVI change through 6 months. 
25. Secondary:  Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 12 Months [ Time Frame: Randomization to 12 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 12 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular End Diastolic Volume Index (a measure of the volume of blood in the left ventricle at the end of diastole, normalized over body surface area). In other words, a measure of the size of the left ventricle. For each subject the measure is the 12 month  randomization visit difference in LVEDVI. Negative values correspond to reductions in LVEDVI over time. 
Time Frame  Randomization to 12 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
261  256 
Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 12 Months [Units: Ml/square meter of body surface area] Mean (Standard Deviation) 
7.0 (20.6)  1.1 (22.2) 
Statistical Analysis 1 for Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  5.807 
95% Confidence Interval  9.467 to 2.038 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEDVI from randomization to 12 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVEDVI from randomization to 12 months than patients with right ventricular pacing. 

[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEDVI change through 12 months. 
26. Secondary:  Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 18 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular End Diastolic Volume Index (a measure of the volume of blood in the left ventricle at the end of diastole, normalized over body surface area). In other words, a measure of the size of the left ventricle. For each subject the measure is the 18 month  randomization visit difference in LVEDVI. Negative values correspond to reductions in LVEDVI over time. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
220  225 
Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 18 Months [Units: Ml/square meter of body surface area] Mean (Standard Deviation) 
9.8 (21.4)  0.8 (22.4) 
Statistical Analysis 1 for Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  8.844 
95% Confidence Interval  12.910 to 4.681 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEDVI from randomization to 18 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVEDVI from randomization to 18 months than patients with right ventricular pacing. 

[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEDVI change through 18 months. 
27. Secondary:  Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 24 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular End Diastolic Volume Index (a measure of the volume of blood in the left ventricle at the end of diastole, normalized over body surface area). In other words, a measure of the size of the left ventricle. For each subject the measure is the 24 month  randomization visit difference in LVEDVI. Negative values correspond to reductions in LVEDVI over time. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
189  206 
Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 24 Months [Units: Ml/square meter of body surface area] Mean (Standard Deviation) 
6.9 (24.9)  0.1 (23.7) 
Statistical Analysis 1 for Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  6.615 
95% Confidence Interval  11.370 to 1.736 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEDVI from randomization to 24 months as corresponding patients who receive right ventricular pacing. This was tested against the hypothesis that patients with biventricular pacing have a different change in LVEDVI from randomization to 24 months than patients with right ventricular pacing.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEDVI change through 24 months. 
28. Secondary:  Change in Left Ventricular Mass (LV Mass) From Randomization to 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular Mass (LV Mass) From Randomization to 6 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular Mass ( a measure of the size of the left ventricle) from randomization to 6 months. For each subject the measurement was calculated as 6 month  randomization visit difference in LV mass measurement. Negative values correspond to a reduction in LV mass over time. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
220  208 
Change in Left Ventricular Mass (LV Mass) From Randomization to 6 Months [Units: Grams] Mean (Standard Deviation) 
8.4 (43.1)  4.2 (47.5) 
Statistical Analysis 1 for Change in Left Ventricular Mass (LV Mass) From Randomization to 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  3.894 
95% Confidence Interval  12.130 to 3.953 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in LV Mass through 6 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in LV Mass through 6 months with BiV pacing than RV pacing. Change was calculated as 6 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LV Mass change through 6 months. 
29. Secondary:  Change in Left Ventricular Mass (LV Mass) From Randomization to 12 Months [ Time Frame: Randomization to 12 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular Mass (LV Mass) From Randomization to 12 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular Mass ( a measure of the size of the left ventricle) from randomization to 12 months. For each subject the measurement was calculated as 12 month  randomization visit difference in LV mass measurement. Negative values correspond to a reduction in LV mass over time. 
Time Frame  Randomization to 12 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
211  199 
Change in Left Ventricular Mass (LV Mass) From Randomization to 12 Months [Units: Grams] Mean (Standard Deviation) 
15.8 (46.8)  4.7 (52.4) 
Statistical Analysis 1 for Change in Left Ventricular Mass (LV Mass) From Randomization to 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  10.160 
95% Confidence Interval  19.330 to 0.857 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in LV Mass through 12 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in LV Mass through 12 months with BiV pacing than RV pacing. Change was calculated as 12 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LV Mass change through 12 months. 
30. Secondary:  Change in Left Ventricular Mass (LV Mass) From Randomization to 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular Mass (LV Mass) From Randomization to 18 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular Mass ( a measure of the size of the left ventricle) from randomization to 18 months. For each subject the measurement was calculated as 18 month  randomization visit difference in LV mass measurement. Negative values correspond to a reduction in LV mass over time. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
168  176 
Change in Left Ventricular Mass (LV Mass) From Randomization to 18 Months [Units: Grams] Mean (Standard Deviation) 
16.8 (48.8)  7.2 (49.8) 
Statistical Analysis 1 for Change in Left Ventricular Mass (LV Mass) From Randomization to 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  8.316 
95% Confidence Interval  18.190 to 1.623 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in LV Mass through 18 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in LV Mass through 18 months with BiV pacing than RV pacing. Change was calculated as 18 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LV Mass change through 18 months. 
31. Secondary:  Change in Left Ventricular Mass (LV Mass) From Randomization to 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular Mass (LV Mass) From Randomization to 24 Months 
Measure Description  The endpoint will be a subject's change in Left Ventricular Mass ( a measure of the size of the left ventricle) from randomization to 24 months. For each subject the measurement was calculated as 24 month  randomization visit difference in LV mass measurement. Negative values correspond to a reduction in LV mass over time. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
150  163 
Change in Left Ventricular Mass (LV Mass) From Randomization to 24 Months [Units: Grams] Mean (Standard Deviation) 
19.4 (45.1)  6.8 (49.6) 
Statistical Analysis 1 for Change in Left Ventricular Mass (LV Mass) From Randomization to 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  11.080 
95% Confidence Interval  21.110 to 0.956 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in LV Mass through 24 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in LV Mass through 24 months with BiV pacing than RV pacing. Change was calculated as 24 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LV Mass change through 24 months. 
32. Secondary:  Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 6 Months 
Measure Description  The endpoint will be a subject's change in LVEDD (a measure of the dimension of the left ventricle at the end of diastole). For each subject the measure was the 6 month  randomization visit difference in LVEDD value. Negative values correspond to reductions in LVEDD. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
254  242 
Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 6 Months [Units: Cm] Mean (Standard Deviation) 
0.1 (0.6)  0.0 (0.6) 
Statistical Analysis 1 for Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.126 
95% Confidence Interval  0.235 to 0.014 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEDD from randomization to 6 months as similar patients who receive right ventricular pacing. This was tested against the hypothesis that patients with BiV pacing have a different change in LVEDD from randomization to 6 months than patients with RV pacing. Negative values reflect reductions in LVEDD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEDD change through 6 months. 
33. Secondary:  Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 12 Months [ Time Frame: Randomization to 12 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 12 Months 
Measure Description  The endpoint will be a subject's change in LVEDD (a measure of the dimension of the left ventricle at the end of diastole). For each subject the measure was the 12 month  randomization visit difference in LVEDD value. Negative values correspond to reductions in LVEDD. 
Time Frame  Randomization to 12 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
241  232 
Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 12 Months [Units: Cm] Mean (Standard Deviation) 
0.1 (0.7)  0.0 (0.7) 
Statistical Analysis 1 for Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.162 
95% Confidence Interval  0.287 to 0.035 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEDD from randomization to 12 months as similar patients who receive right ventricular pacing. This was tested against the hypothesis that patients with BiV pacing have a different change in LVEDD from randomization to 12 months than patients with RV pacing. Negative values reflect reductions in LVEDD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEDD change through 12 months. 
34. Secondary:  Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 18 Months 
Measure Description  The endpoint will be a subject's change in LVEDD (a measure of the dimension of the left ventricle at the end of diastole). For each subject the measure was the 18 month  randomization visit difference in LVEDD value. Negative values correspond to reductions in LVEDD. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
201  204 
Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 18 Months [Units: Cm] Mean (Standard Deviation) 
0.2 (0.6)  0.0 (0.7) 
Statistical Analysis 1 for Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.163 
95% Confidence Interval  0.293 to 0.030 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEDD from randomization to 18 months as similar patients who receive right ventricular pacing. This was tested against the hypothesis that patients with BiV pacing have a different change in LVEDD from randomization to 18 months than patients with RV pacing. Negative values reflect reductions in LVEDD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEDD change through 18 months. 
35. Secondary:  Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 24 Months 
Measure Description  The endpoint will be a subject's change in LVEDD (a measure of the dimension of the left ventricle at the end of diastole). For each subject the measure was the 24 month  randomization visit difference in LVEDD value. Negative values correspond to reductions in LVEDD. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
175  186 
Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 24 Months [Units: Cm] Mean (Standard Deviation) 
0.3 (0.7)  0.0 (0.7) 
Statistical Analysis 1 for Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.245 
95% Confidence Interval  0.390 to 0.097 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVEDD from randomization to 24 months as similar patients who receive right ventricular pacing. This was tested against the hypothesis that patients with BiV pacing have a different change in LVEDD from randomization to 24 months than patients with RV pacing. Negative values reflect reductions in LVEDD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVEDD change through 24 months. 
36. Secondary:  Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 6 Months 
Measure Description  The endpoint will be a subject's change in LVESD (a measure of the dimension of the left ventricle at the end of systole). For each subject the measure was the 6 month  randomization visit difference in LVESD value. Negative values correspond to reductions in LVESD. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
250  241 
Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 6 Months [Units: Cm] Mean (Standard Deviation) 
0.1 (0.6)  0.0 (0.7) 
Statistical Analysis 1 for Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.066 
95% Confidence Interval  0.185 to 0.055 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVESD from randomization to 6 months as similar patients who receive right ventricular pacing. This was tested against the hypothesis that patients with BiV pacing have a different change in LVESD from randomization to 6 months than patients with RV pacing. Negative values reflect reductions in LVESD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVESD change through 6 months. 
37. Secondary:  Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 12 Months [ Time Frame: Randomization to 12 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 12 Months 
Measure Description  The endpoint will be a subject's change in LVESD (a measure of the dimension of the left ventricle at the end of systole). For each subject the measure was the 12 month  randomization visit difference in LVESD value. Negative values correspond to reductions in LVESD. 
Time Frame  Randomization to 12 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
239  231 
Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 12 Months [Units: Cm] Mean (Standard Deviation) 
0.0 (0.7)  0.1 (0.7) 
Statistical Analysis 1 for Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.104 
95% Confidence Interval  0.236 to 0.029 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVESD from randomization to 12 months as similar patients who receive right ventricular pacing. This was tested against the hypothesis that patients with BiV pacing have a different change in LVESD from randomization to 12 months than patients with RV pacing. Negative values reflect reductions in LVESD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVESD change through 12 months. 
38. Secondary:  Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 18 Months 
Measure Description  The endpoint will be a subject's change in LVESD (a measure of the dimension of the left ventricle at the end of systole). For each subject the measure was the 18 month  randomization visit difference in LVESD value. Negative values correspond to reductions in LVESD. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
199  204 
Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 18 Months [Units: Cm] Mean (Standard Deviation) 
0.1 (0.7)  0.0 (0.7) 
Statistical Analysis 1 for Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.060 
95% Confidence Interval  0.204 to 0.087 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVESD from randomization to 18 months as similar patients who receive right ventricular pacing. This was tested against the hypothesis that patients with BiV pacing have a different change in LVESD from randomization to 18 months than patients with RV pacing. Negative values reflect reductions in LVESD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVESD change through 18 months. 
39. Secondary:  Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 24 Months 
Measure Description  The endpoint will be a subject's change in LVESD (a measure of the dimension of the left ventricle at the end of systole). For each subject the measure was the 24 month  randomization visit difference in LVESD value. Negative values correspond to reductions in LVESD. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
173  185 
Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 24 Months [Units: Cm] Mean (Standard Deviation) 
0.1 (0.8)  0.1 (0.7) 
Statistical Analysis 1 for Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.180 
95% Confidence Interval  0.339 to 0.018 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, ejection fractions of at most 50%, and NYHA classifications of I, II, or III who receive biventricular pacing have the same average change in LVESD from randomization to 24 months as similar patients who receive right ventricular pacing. This was tested against the hypothesis that patients with BiV pacing have a different change in LVESD from randomization to 24 months than patients with RV pacing. Negative values reflect reductions in LVESD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean LVESD change through 24 months. 
40. Secondary:  Change in Mitral Regurgitation From Randomization to 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in Mitral Regurgitation From Randomization to 6 Months 
Measure Description  The endpoint will be a subject's change in mitral regurgitation (a measure of how much blood flows backwards into the heart due to the mitral valve not closing properly). The measure for each subject will be the 6 month  randomization visit difference in mitral regurgitation. Negative values reflect reductions in mitral regurgitation over time. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
247  225 
Change in Mitral Regurgitation From Randomization to 6 Months [Units: Percentage of left atrial area] Mean (Standard Deviation) 
1.3 (12.4)  0.6 (11.2) 
Statistical Analysis 1 for Change in Mitral Regurgitation From Randomization to 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.683 
95% Confidence Interval  2.828 to 1.506 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in Mitral Regurgitation (MR) through 6 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in Mitral Regurgitation through 6 months with BiV pacing than RV pacing. Change was calculated as 6 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean MR change through 6 months. 
41. Secondary:  Change in Mitral Regurgitation From Randomization to 12 Months [ Time Frame: Randomization to 12 Months ] 
Measure Type  Secondary 

Measure Title  Change in Mitral Regurgitation From Randomization to 12 Months 
Measure Description  The endpoint will be a subject's change in mitral regurgitation (a measure of how much blood flows backwards into the heart due to the mitral valve not closing properly). The measure for each subject will be the 12 month  randomization visit difference in mitral regurgitation. Negative values reflect reductions in mitral regurgitation over time. 
Time Frame  Randomization to 12 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
235  214 
Change in Mitral Regurgitation From Randomization to 12 Months [Units: Percentage of left atrial area] Mean (Standard Deviation) 
1.3 (12.0)  0.8 (12.6) 
Statistical Analysis 1 for Change in Mitral Regurgitation From Randomization to 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.564 
95% Confidence Interval  2.843 to 1.773 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in Mitral Regurgitation (MR) through 12 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in Mitral Regurgitation through 12 months with BiV pacing than RV pacing. Change was calculated as 12 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean MR change through 12 months. 
42. Secondary:  Change in Mitral Regurgitation From Randomization to 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in Mitral Regurgitation From Randomization to 18 Months 
Measure Description  The endpoint will be a subject's change in mitral regurgitation (a measure of how much blood flows backwards into the heart due to the mitral valve not closing properly). The measure for each subject will be the 18 month  randomization visit difference in mitral regurgitation. Negative values reflect reductions in mitral regurgitation over time. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
188  195 
Change in Mitral Regurgitation From Randomization to 18 Months [Units: Percentage of left atrial area] Mean (Standard Deviation) 
1.9 (12.1)  1.9 (11.5) 
Statistical Analysis 1 for Change in Mitral Regurgitation From Randomization to 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.016 
95% Confidence Interval  2.379 to 2.425 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in Mitral Regurgitation (MR) through 18 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in Mitral Regurgitation through 18 months with BiV pacing than RV pacing. Change was calculated as 18 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean MR change through 18 months. 
43. Secondary:  Change in Mitral Regurgitation From Randomization to 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Mitral Regurgitation From Randomization to 24 Months 
Measure Description  The endpoint will be a subject's change in mitral regurgitation (a measure of how much blood flows backwards into the heart due to the mitral valve not closing properly). The measure for each subject will be the 24 month  randomization visit difference in mitral regurgitation. Negative values reflect reductions in mitral regurgitation over time. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
173  173 
Change in Mitral Regurgitation From Randomization to 24 Months [Units: Percentage of left atrial area] Mean (Standard Deviation) 
1.1 (13.6)  0.5 (11.4) 
Statistical Analysis 1 for Change in Mitral Regurgitation From Randomization to 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.653 
95% Confidence Interval  3.337 to 2.046 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in Mitral Regurgitation (MR) through 24 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in Mitral Regurgitation through 24 months with BiV pacing than RV pacing. Change was calculated as 24 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean MR change through 24 months. 
44. Secondary:  Change in Cardiac Index From Randomization to 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in Cardiac Index From Randomization to 6 Months 
Measure Description  The endpoint will be a subject's change in cardiac index (a measure of how much blood the left ventricle ejects in one minute, normalized over body surface area) from randomization to 6 months. The measure for each subject will be the 6 month  randomization visit value. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
275  268 
Change in Cardiac Index From Randomization to 6 Months [Units: Liters per minute per squared meter] Mean (Standard Deviation) 
0 (0.6)  0.1 (0.7) 
Statistical Analysis 1 for Change in Cardiac Index From Randomization to 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.080 
95% Confidence Interval  0.031 to 0.195 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in Cardiac Index (CI) through 6 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in Cardiac Index through 6 months with BiV pacing than RV pacing. Change was calculated as 6 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean CI change through 6 months. 
45. Secondary:  Change in Cardiac Index From Randomization to 12 Months [ Time Frame: Randomization to 12 Months ] 
Measure Type  Secondary 

Measure Title  Change in Cardiac Index From Randomization to 12 Months 
Measure Description  The endpoint will be a subject's change in cardiac index (a measure of how much blood the left ventricle ejects in one minute, normalized over body surface area) from randomization to 12 months. The measure for each subject will be the 12 month  randomization visit value. 
Time Frame  Randomization to 12 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
257  250 
Change in Cardiac Index From Randomization to 12 Months [Units: Liters per minute per squared meter] Mean (Standard Deviation) 
0.1 (0.6)  0.2 (0.6) 
Statistical Analysis 1 for Change in Cardiac Index From Randomization to 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.086 
95% Confidence Interval  0.022 to 0.198 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in Cardiac Index (CI) through 12 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in Cardiac Index through 12 months with BiV pacing than RV pacing. Change was calculated as 12 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean CI change through 12 months. 
46. Secondary:  Change in Cardiac Index From Randomization to 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in Cardiac Index From Randomization to 18 Months 
Measure Description  The endpoint will be a subject's change in cardiac index (a measure of how much blood the left ventricle ejects in one minute, normalized over body surface area) from randomization to 18 months. The measure for each subject will be the 18 month  randomization visit value. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
215  218 
Change in Cardiac Index From Randomization to 18 Months [Units: Liters per minute per squared meter] Mean (Standard Deviation) 
0.1 (0.7)  0 (0.7) 
Statistical Analysis 1 for Change in Cardiac Index From Randomization to 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.081 
95% Confidence Interval  0.218 to 0.058 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in Cardiac Index (CI) through 18 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in Cardiac Index through 18 months with BiV pacing than RV pacing. Change was calculated as 18 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean CI change through 18 months. 
47. Secondary:  Change in Cardiac Index From Randomization to 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Cardiac Index From Randomization to 24 Months 
Measure Description  The endpoint will be a subject's change in cardiac index (a measure of how much blood the left ventricle ejects in one minute, normalized over body surface area) from randomization to 24 months. The measure for each subject will be the 24 month  randomization visit value. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
186  198 
Change in Cardiac Index From Randomization to 24 Months [Units: Liters per minute per squared meter] Mean (Standard Deviation) 
0.1 (0.7)  0.2 (0.7) 
Statistical Analysis 1 for Change in Cardiac Index From Randomization to 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.047 
95% Confidence Interval  0.095 to 0.192 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in Cardiac Index (CI) through 24 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in Cardiac Index through 24 months with BiV pacing than RV pacing. Change was calculated as 24 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean CI change through 24 months. 
48. Secondary:  Change in Interventricular Mechanical Delay (IVMD) From Randomization to 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in Interventricular Mechanical Delay (IVMD) From Randomization to 6 Months 
Measure Description  The endpoint will be a subject's change in interventricular mechanical delay (a measure of dyssynchrony between ventricles, measured in ms) from randomization to the 6 month visit. The measure will be the 6 month  randomization visit difference in IVMD. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
220  208 
Change in Interventricular Mechanical Delay (IVMD) From Randomization to 6 Months [Units: Ms] Mean (Standard Deviation) 
49.9 (134.2)  4.2 (136.1) 
Statistical Analysis 1 for Change in Interventricular Mechanical Delay (IVMD) From Randomization to 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  29.300 
95% Confidence Interval  10.040 to 48.640 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in IVMD through 6 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in IVMD through 6 months with BiV pacing than RV pacing. Change was calculated as 6 month value  randomization visit value. A positive value reflected reduction in IVMD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean IVMD change through 6 months. 
49. Secondary:  Change in Interventricular Mechanical Delay (IVMD) From Randomization to 12 Months [ Time Frame: Randomization to 12 Months ] 
Measure Type  Secondary 

Measure Title  Change in Interventricular Mechanical Delay (IVMD) From Randomization to 12 Months 
Measure Description  The endpoint will be a subject's change in interventricular mechanical delay (a measure of dyssynchrony between ventricles, measured in ms) from randomization to the 12 month visit. The measure will be the 12 month  randomization visit difference in IVMD. 
Time Frame  Randomization to 12 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
202  198 
Change in Interventricular Mechanical Delay (IVMD) From Randomization to 12 Months [Units: Ms] Mean (Standard Deviation) 
38.5 (121.9)  0.4 (128.9) 
Statistical Analysis 1 for Change in Interventricular Mechanical Delay (IVMD) From Randomization to 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  21.830 
95% Confidence Interval  2.841 to 40.870 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in IVMD through 6 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in IVMD through 12 months with BiV pacing than RV pacing. Change was calculated as 12 month value  randomization visit value. A positive value reflected reduction in IVMD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean IVMD change through 12 months. 
50. Secondary:  Change in Interventricular Mechanical Delay (IVMD) From Randomization to 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in Interventricular Mechanical Delay (IVMD) From Randomization to 18 Months 
Measure Description  The endpoint will be a subject's change in interventricular mechanical delay (a measure of dyssynchrony between ventricles, measured in ms) from randomization to the 18 month visit. The measure will be the 18 month  randomization visit difference in IVMD. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
173  172 
Change in Interventricular Mechanical Delay (IVMD) From Randomization to 18 Months [Units: Ms] Mean (Standard Deviation) 
55.1 (135.7)  0.8 (136.7) 
Statistical Analysis 1 for Change in Interventricular Mechanical Delay (IVMD) From Randomization to 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  26.530 
95% Confidence Interval  6.247 to 47.190 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in IVMD through 6 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in IVMD through 18 months with BiV pacing than RV pacing. Change was calculated as 18 month value  randomization visit value. A positive value reflected reduction in IVMD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean IVMD change through 18 months. 
51. Secondary:  Change in Interventricular Mechanical Delay (IVMD) From Randomization to 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in Interventricular Mechanical Delay (IVMD) From Randomization to 24 Months 
Measure Description  The endpoint will be a subject's change in interventricular mechanical delay (a measure of dyssynchrony between ventricles, measured in ms) from randomization to the 24 month visit. The measure will be the 24 month  randomization visit difference in IVMD. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
150  160 
Change in Interventricular Mechanical Delay (IVMD) From Randomization to 24 Months [Units: Ms] Mean (Standard Deviation) 
48.6 (138.1)  4.9 (133.3) 
Statistical Analysis 1 for Change in Interventricular Mechanical Delay (IVMD) From Randomization to 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  23.32 
95% Confidence Interval  1.999 to 44.530 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in IVMD through 6 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in IVMD through 24 months with BiV pacing than RV pacing. Change was calculated as 24 month value  randomization visit value. A positive value reflected reduction in IVMD.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean IVMD change through 24 months. 
52. Secondary:  Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 6 Months 
Measure Description  The endpoint will be a subject's change in E:A ratio (a measure of diastolic function) from randomization to 6 months. The measure for each subject will be the 6 month  randomization visit difference in E:A ratio. Typical values for the E:A ratio at a single time point are 1.04 in men and 1.03 in women. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
221  194 
Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 6 Months [Units: Ratio] Mean (Standard Deviation) 
0 (0.6)  0 (0.7) 
Statistical Analysis 1 for Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.047 
95% Confidence Interval  0.180 to 0.089 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in E:A ratio (E/A) through 6 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in E:A ratio through 6 months with BiV pacing than RV pacing. Change was calculated as 6 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean E/A change through 6 months. 
53. Secondary:  Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 12 Months [ Time Frame: Randomization to 12 Months ] 
Measure Type  Secondary 

Measure Title  Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 12 Months 
Measure Description  The endpoint will be a subject's change in E:A ratio (a measure of diastolic function) from randomization to 12 months. The measure for each subject will be the 12 month  randomization visit difference in E:A ratio. Typical values for the E:A ratio at a single time point are 1.04 in men and 1.03 in women. 
Time Frame  Randomization to 12 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
208  188 
Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 12 Months [Units: Ratio] Mean (Standard Deviation) 
0.1 (0.7)  0.2 (1.0) 
Statistical Analysis 1 for Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 12 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.117 
95% Confidence Interval  0.287 to 0.058 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in E:A ratio (E/A) through 12 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in E:A ratio through 12 months with BiV pacing than RV pacing. Change was calculated as 12 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean E/A change through 12 months. 
54. Secondary:  Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 18 Months [ Time Frame: Randomization to 18 Months ] 
Measure Type  Secondary 

Measure Title  Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 18 Months 
Measure Description  The endpoint will be a subject's change in E:A ratio (a measure of diastolic function) from randomization to 18 months. The measure for each subject will be the 18 month  randomization visit difference in E:A ratio. Typical values for the E:A ratio at a single time point are 1.04 in men and 1.03 in women. 
Time Frame  Randomization to 18 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
174  159 
Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 18 Months [Units: Ratio] Mean (Standard Deviation) 
0.1 (0.8)  0.1 (0.8) 
Statistical Analysis 1 for Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 18 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.041 
95% Confidence Interval  0.136 to 0.220 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in E:A ratio (E/A) through 18 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in E:A ratio through 18 months with BiV pacing than RV pacing. Change was calculated as 18 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean E/A change through 18 months. 
55. Secondary:  Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 24 Months [ Time Frame: Randomization to 24 Months ] 
Measure Type  Secondary 

Measure Title  Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 24 Months 
Measure Description  The endpoint will be a subject's change in E:A ratio (a measure of diastolic function) from randomization to 24 months. The measure for each subject will be the 24 month  randomization visit difference in E:A ratio. Typical values for the E:A ratio at a single time point are 1.04 in men and 1.03 in women. 
Time Frame  Randomization to 24 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

No text entered. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
160  141 
Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 24 Months [Units: Ratio] Mean (Standard Deviation) 
0.2 (0.8)  0.1 (0.9) 
Statistical Analysis 1 for Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 24 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Bayesian Credible Interval 
Posterior BiV  RV Mean Difference ^{[4]}  0.110 
95% Confidence Interval  0.085 to 0.311 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar changes in E:A ratio (E/A) through 24 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients have different changes in E:A ratio through 24 months with BiV pacing than RV pacing. Change was calculated as 24 month value  randomization visit value.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
No text entered.  
[4]  Other relevant estimation information: 
Because Bayesian analyses were employed, a 95% twosided credible interval was used instead of a confidence interval. This reflects the 2.5th and 97.5th percentile of possible values for the BiVRV difference in mean E/A change through 24 months. 
56. Secondary:  Clinical Composite Score at 6 Months [ Time Frame: Randomization to 6 Months ] 
Measure Type  Secondary 

Measure Title  Clinical Composite Score at 6 Months 
Measure Description  The endpoint will be a subject's Clinical Composite Score at 6 months. The Clinical Composite Score is a 3 point score (Worsened, Unchanged, and Improved) based on a number of factors including: whether the subject has died, whether the subject has experienced a heart failurerelated hospitalization, whether the subject has discontinued their therapy due to worsening heart failure, whether their New York Heart Association classification has improved or worsened since randomization, and whether they feel moderately or markedly better since randomization. 
Time Frame  Randomization to 6 Months 
Population Description
Explanation of how the number of participants for analysis was determined. Includes whether analysis was per protocol, intention to treat, or another method. Also provides relevant details such as imputation technique, as appropriate. 

Only randomized subjects in both device groups were included in the analysis of this endpoint, as the analysis was restricted to postrandomization data. Subjects in the "No Implant Attempt", "Unsuccessful Implants", "CRTP: Not Randomized", and "CRTD: Not Randomized" subgroups were excluded. 
Reporting Groups
Description  

Biventricular Pacing Arm  Subjects randomized to receive biventricular pacing 
Right Ventricular Pacing Arm  Subjects randomized to receive right ventricular pacing. 
Measured Values
Biventricular Pacing Arm  Right Ventricular Pacing Arm  

Participants Analyzed [Units: Participants] 
349  342 
Clinical Composite Score at 6 Months [Units: Participants] 

Improved  184  133 
Unchanged  83  113 
Worsened  82  96 
Statistical Analysis 1 for Clinical Composite Score at 6 Months
Groups ^{[1]}  All groups 

Statistical Test Type ^{[2]}  Superiority or Other 
Statistical Method ^{[3]}  Posterior probability of mean difference 
P Value ^{[4]}  0.9985 
Mean Difference (Final Values) ^{[5]}  0.1841 
[1]  Additional details about the analysis, such as null hypothesis and power calculation: 

The null hypothesis is that patients with AV block, NYHA IIII, and LVEF of at most 50% who receive RV pacing have similar Clinical Composite Scores after 6 months compared to similar patients who receive BiV pacing. This was tested against the alternative hypothesis that patients had better scores with BiV pacing than RV pacing. The analysis assigned numerical values (Improved=3, Unchanged=2, Worsened=1) and compared the average score between randomization arms using a onesided analysis.  
[2]  Details of power calculation, definition of noninferiority margin, and other key parameters: 
No text entered.  
[3]  Other relevant method information, such as adjustments or degrees of freedom: 
The posterior probability that the mean difference is greater than 0 was calculated.  
[4]  Additional information, such as whether or not the pvalue is adjusted for multiple comparisons and the a priori threshold for statistical significance: 
BLOCK HF is a Bayesian study; a pvalue was not used. Instead, a posterior probability, representing the probability that subjects with biventricular pacing have better outcomes, was calculated. A probability ≥ 0.95 was significant.  
[5]  Other relevant estimation information: 
This was a onesided analysis of the BiV arm  RV arm difference in Mean Clinical Composite Scores. Values above 0 suggested better outcomes in the Biventricular arm. 