Now Available: Final Rule for FDAAA 801 and NIH Policy on Clinical Trial Reporting

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

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Medtronic Cardiac Rhythm and Heart Failure
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 
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
  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 ]

8.  Secondary:   Change in Heart Failure Stage   [ Time Frame: Randomization to 24 Months ]
  Hide Outcome Measure 8

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  
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 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
Method [2] Posterior Distribution for Average Rank
P Value [3] 0.534
BiV - RV Difference in Average Rank [4] 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] 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.
[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 Heart Failure Stage
Groups [1] All groups
Method [2] Posterior Distribution for Average Rank
P Value [3] 0.825
BiV - RV Difference in Average Rank [4] 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] 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.
[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 Heart Failure Stage
Groups [1] All groups
Method [2] Posterior Distribution for Average Rank
P Value [3] 0.651
BiV - RV Difference in Average Rank [4] 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] 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.
[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 18 months, was calculated. A probability ≥0.95 was significant.
[4] 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
Method [2] Posterior Distribution for Average Rank
P Value [3] 0.425
BiV - RV Difference in Average Rank [4] -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] 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.
[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 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 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


Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Responsible Party: Medtronic Cardiac Rhythm and Heart Failure
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