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

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Medtronic Cardiac Rhythm Disease Management
ClinicalTrials.gov Identifier:
NCT00267098
First received: December 19, 2005
Last updated: February 20, 2014
Last verified: February 2014
Results First Received: December 18, 2013  
Study Type: Interventional
Study Design: Allocation: Randomized;   Endpoint Classification: Safety/Efficacy Study;   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
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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.

Pre-Assignment 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 CRT-P or CRT-D device and were not randomized
Unsuccessful Implants Subjects who underwent an implant attempt of a CRT-P or CRT-D device but were not successfully implanted
CRT-P: Biventricular Pacing Arm Subjects who were implanted with a CRT-P device and randomized to receive biventricular pacing
CRT-P: Right Ventricular Pacing Arm Subjects who were implanted with a CRT-P device and randomized to receive right ventricular pacing
CRT-P: Not Randomized Subjects successfully implanted with a CRT-P device who were not randomized
CRT-D: Biventricular Pacing Arm Subjects implanted with a CRT-D device and randomized to receive biventricular pacing
CRT-D: Right Ventricular Pacing Arm Subjects implanted with a CRT-D device and randomized to receive right ventricular pacing.
CRT-D: Not Randomized Subjects successfully implanted with a CRT-D device who were not randomized

Participant Flow:   Overall Study
    No Implant Attempt     Unsuccessful Implants     CRT-P: Biventricular Pacing Arm     CRT-P: Right Ventricular Pacing Arm     CRT-P: Not Randomized     CRT-D: Biventricular Pacing Arm     CRT-D: Right Ventricular Pacing Arm     CRT-D: 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 Follow-up                 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  
Non-Medtronic 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
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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 CRT-P or CRT-D device and were not randomized
Unsuccessful Implants Subjects who underwent an implant attempt of a CRT-P or CRT-D device but were not successfully implanted
CRT-P: Biventricular Pacing Arm Subjects who were implanted with a CRT-P device and randomized to receive biventricular pacing
CRT-P: Right Ventricular Pacing Arm Subjects who were implanted with a CRT-P device and randomized to receive right ventricular pacing
CRT-P: Not Randomized Subjects successfully implanted with a CRT-P device who were not randomized
CRT-D: Biventricular Pacing Arm Subjects implanted with a CRT-D device and randomized to receive biventricular pacing
CRT-D: Right Ventricular Pacing Arm Subjects implanted with a CRT-D device and randomized to receive right ventricular pacing.
CRT-D: Not Randomized Subjects successfully implanted with a CRT-D device who were not randomized
Total Total of all reporting groups

Baseline Measures
    No Implant Attempt     Unsuccessful Implants     CRT-P: Biventricular Pacing Arm     CRT-P: Right Ventricular Pacing Arm     CRT-P: Not Randomized     CRT-D: Biventricular Pacing Arm     CRT-D: Right Ventricular Pacing Arm     CRT-D: Not Randomized     Total  
Number of Participants  
[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
  Show All Outcome Measures

1.  Primary:   Mortality, Heart Failure-related 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 post-randomization. ]

2.  Secondary:   All-Cause Mortality   [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months post-randomization. ]

3.  Secondary:   All-Cause Mortality or Heart Failure-related Hospitalization   [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months post-randomization. ]

4.  Secondary:   All-Cause 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 post-randomization. ]

5.  Secondary:   First Heart Failure Hospitalization   [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months post-randomization. ]

6.  Secondary:   Days Hospitalized for Heart Failure   [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months post-randomization. ]

7.  Secondary:   Change in New York Heart Association Classification   [ Time Frame: Randomization to 24 Months ]
  Hide Outcome Measure 7

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 post-randomization. The change categories listed will be relative to randomization.
Time Frame Randomization to 24 Months  
Safety Issue No  

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  
Number of 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
Method [2] Posterior Distribution for Average Rank
P Value [3] 0.591
BiV - RV Difference in Average Rank [4] 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] 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.
[3] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  BLOCK HF is a Bayesian study; thus p-values 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.
[4] 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
Method [2] Posterior Distribution for Average Rank
P Value [3] 0.986
BiV - RV Difference in Average Rank [4] 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] 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.
[3] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  BLOCK HF is a Bayesian study; thus p-values 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.
[4] 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
Method [2] Posterior Distribution for Average Rank
P Value [3] 0.726
BiV - RV Difference in Average Rank [4] 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] 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.
[3] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  BLOCK HF is a Bayesian study; thus p-values 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.
[4] 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
Method [2] Posterior Distribution for Average Rank
P Value [3] 0.701
BiV - RV Difference in Average Rank [4] 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] 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.
[3] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  BLOCK HF is a Bayesian study; thus p-values 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.
[4] 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 ]

9.  Secondary:   Change in Cardiovascular Medications   [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months post-randomization. ]

10.  Secondary:   Frequency of Adverse Events Post-randomization   [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months post-randomization. ]

11.  Secondary:   Cardiovascular-related Healthcare Utilizations   [ Time Frame: Participants were followed for the duration of the study, an average of 39.8 months post-randomization. ]

12.  Secondary:   Change in Quality of Life at 6 Months   [ Time Frame: Randomization to 6 Months ]

13.  Secondary:   Change in Quality of Life at 12 Months   [ Time Frame: Randomization to 12 months ]

14.  Secondary:   Change in Quality of Life at 18 Months   [ Time Frame: Randomization to 18 Months ]

15.  Secondary:   Change in Quality of Life at 24 Months   [ Time Frame: Randomization to 24 Months ]

16.  Secondary:   Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 6 Months   [ Time Frame: Randomization to 6 Months ]

17.  Secondary:   Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 12 Months   [ Time Frame: Randomization to 12 Months ]

18.  Secondary:   Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 18 Months   [ Time Frame: Randomization to 18 Months ]

19.  Secondary:   Change in Left Ventricular Ejection Fraction (LVEF) From Randomization to 24 Months   [ Time Frame: Randomization to 24 Months ]

20.  Secondary:   Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 6 Months   [ Time Frame: Randomization to 6 Months ]

21.  Secondary:   Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 12 Months   [ Time Frame: Randomization to 12 Months ]

22.  Secondary:   Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 18 Months   [ Time Frame: Randomization to 18 Months ]

23.  Secondary:   Change in Left Ventricular End Systolic Volume Index (LVESVI) From Randomization to 24 Months   [ Time Frame: Randomization to 24 Months ]

24.  Secondary:   Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 6 Months   [ Time Frame: Randomization to 6 Months ]

25.  Secondary:   Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 12 Months   [ Time Frame: Randomization to 12 Months ]

26.  Secondary:   Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 18 Months   [ Time Frame: Randomization to 18 Months ]

27.  Secondary:   Change in Left Ventricular End Diastolic Volume Index (LVEDVI) From Randomization to 24 Months   [ Time Frame: Randomization to 24 Months ]

28.  Secondary:   Change in Left Ventricular Mass (LV Mass) From Randomization to 6 Months   [ Time Frame: Randomization to 6 Months ]

29.  Secondary:   Change in Left Ventricular Mass (LV Mass) From Randomization to 12 Months   [ Time Frame: Randomization to 12 Months ]

30.  Secondary:   Change in Left Ventricular Mass (LV Mass) From Randomization to 18 Months   [ Time Frame: Randomization to 18 Months ]

31.  Secondary:   Change in Left Ventricular Mass (LV Mass) From Randomization to 24 Months   [ Time Frame: Randomization to 24 Months ]

32.  Secondary:   Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 6 Months   [ Time Frame: Randomization to 6 Months ]

33.  Secondary:   Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 12 Months   [ Time Frame: Randomization to 12 Months ]

34.  Secondary:   Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 18 Months   [ Time Frame: Randomization to 18 Months ]

35.  Secondary:   Change in Left Ventricular End Diastolic Dimension (LVEDD) From Randomization to 24 Months   [ Time Frame: Randomization to 24 Months ]

36.  Secondary:   Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 6 Months   [ Time Frame: Randomization to 6 Months ]

37.  Secondary:   Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 12 Months   [ Time Frame: Randomization to 12 Months ]

38.  Secondary:   Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 18 Months   [ Time Frame: Randomization to 18 Months ]

39.  Secondary:   Change in Left Ventricular End Systolic Dimension (LVESD) From Randomization to 24 Months   [ Time Frame: Randomization to 24 Months ]

40.  Secondary:   Change in Mitral Regurgitation From Randomization to 6 Months   [ Time Frame: Randomization to 6 Months ]

41.  Secondary:   Change in Mitral Regurgitation From Randomization to 12 Months   [ Time Frame: Randomization to 12 Months ]

42.  Secondary:   Change in Mitral Regurgitation From Randomization to 18 Months   [ Time Frame: Randomization to 18 Months ]

43.  Secondary:   Change in Mitral Regurgitation From Randomization to 24 Months   [ Time Frame: Randomization to 24 Months ]

44.  Secondary:   Change in Cardiac Index From Randomization to 6 Months   [ Time Frame: Randomization to 6 Months ]

45.  Secondary:   Change in Cardiac Index From Randomization to 12 Months   [ Time Frame: Randomization to 12 Months ]

46.  Secondary:   Change in Cardiac Index From Randomization to 18 Months   [ Time Frame: Randomization to 18 Months ]

47.  Secondary:   Change in Cardiac Index From Randomization to 24 Months   [ Time Frame: Randomization to 24 Months ]

48.  Secondary:   Change in Interventricular Mechanical Delay (IVMD) From Randomization to 6 Months   [ Time Frame: Randomization to 6 Months ]

49.  Secondary:   Change in Interventricular Mechanical Delay (IVMD) From Randomization to 12 Months   [ Time Frame: Randomization to 12 Months ]

50.  Secondary:   Change in Interventricular Mechanical Delay (IVMD) From Randomization to 18 Months   [ Time Frame: Randomization to 18 Months ]

51.  Secondary:   Change in Interventricular Mechanical Delay (IVMD) From Randomization to 24 Months   [ Time Frame: Randomization to 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 ]

53.  Secondary:   Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 12 Months   [ Time Frame: Randomization to 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 ]

55.  Secondary:   Change in E Wave/A Wave Ratio (E:A Ratio) From Randomization to 24 Months   [ Time Frame: Randomization to 24 Months ]

56.  Secondary:   Clinical Composite Score at 6 Months   [ Time Frame: Randomization to 6 Months ]

57.  Secondary:   Clinical Composite Score at 12 Months   [ Time Frame: Randomization to 12 Months ]

58.  Secondary:   Clinical Composite Score at 18 Months   [ Time Frame: Randomization to 18 Months ]

59.  Secondary:   Clinical Composite Score at 24 Months   [ Time Frame: Randomization to 24 Months ]

60.  Secondary:   CRT-P and CRT-D System Implant Success   [ Time Frame: Initial Implant Procedure ]

61.  Secondary:   Incidence of Ventricular Tachyarrhythmias   [ Time Frame: Participants were followed for the duration of the study, an average of 37.9 months post-randomization among CRT-D subjects. ]


  Serious Adverse Events


  Other Adverse Events


  Limitations and Caveats
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Limitations of the study, such as early termination leading to small numbers of participants analyzed and technical problems with measurement leading to unreliable or uninterpretable data
No text entered.


  More Information
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Certain Agreements:  
Principal Investigators are NOT employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.


Results Point of Contact:  
Name/Title: BLOCK HF Clinical Trial Leader
Organization: Medtronic CRDM Clinical
phone: 763-526-2729
e-mail: medtroniccrmtrials@medtronic.com


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Responsible Party: Medtronic Cardiac Rhythm Disease Management
ClinicalTrials.gov Identifier: NCT00267098     History of Changes
Other Study ID Numbers: 215
Study First Received: December 19, 2005
Results First Received: December 18, 2013
Last Updated: February 20, 2014
Health Authority: United States: Food and Drug Administration