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PEGASUS CRT Study: Atrial Support Study in Cardiac Resynchronization Therapy

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Boston Scientific Corporation
ClinicalTrials.gov Identifier:
NCT00146848
First received: September 2, 2005
Last updated: December 20, 2011
Last verified: December 2011
History of Changes
Results First Received: February 28, 2010  
Study Type: Interventional
Study Design: Allocation: Randomized;   Endpoint Classification: Efficacy Study;   Intervention Model: Parallel Assignment;   Masking: Single Blind (Subject);   Primary Purpose: Treatment
Condition: Heart Failure
Intervention: Device: Atrial support pacing through cardiac resynchronization therapy. Device: RENEWAL family of CRT-D devices

  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
Enrollment began on November 8, 2004, was completed on December 21, 2007, with study follow-up commencing January 30, 2009. This trial was conducted at institutional settings throughout the United States and Australia.

Pre-Assignment Details
Significant events and approaches for the overall study following participant enrollment, but prior to group assignment
All patients with successful system implants were programmed to DDD-40 (atrial rate support above 40 bpm; limited atrial pacing) for the first 6-weeks of the trial. Randomization (1:1:1 allocation) occurred after patients had reached the 6-week visit and continued to meet all of the eligibility criteria for the trial.

Reporting Groups
  Description
DDD-40 Atrial Tracking (atrial rate support above 40 bpm)
DDD-70 Atrial Rate Support (atrial rate support above 70 bpm)
DDDR-40 Rate Adaptive Pacing (atrial rate support above 40 bpm with rate responsive pacing)

Participant Flow for 2 periods

 Period 1:   Pre-randomization
    DDD-40     DDD-70     DDDR-40  
STARTED     1742 [1]   0     0  
COMPLETED     1433 [2]   0     0  
NOT COMPLETED     309     0     0  
Death                 19                 0                 0  
Lost to Follow-up                 70                 0                 0  
Physician Decision                 8                 0                 0  
Protocol Violation                 172                 0                 0  
Withdrawal by Subject                 40                 0                 0  
[1] Registered
[2] Reached 6-week visit and were randomized

Period 2:   Post-randomization
    DDD-40     DDD-70     DDDR-40  
STARTED     475     488     470  
COMPLETED     437     441     431  
NOT COMPLETED     38     47     39  
Lost to Follow-up                 12                 15                 12  
Withdrawn                 26                 32                 27  



  Baseline Characteristics
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Reporting Groups
  Description
DDD-40 Atrial Tracking (atrial rate support above 40 bpm)
DDD-70 Atrial Rate Support (atrial rate support above 70 bpm)
DDDR-40 Rate Adaptive Pacing (atrial rate support above 40 bpm with rate responsive pacing)
Total Total of all reporting groups

Baseline Measures
    DDD-40     DDD-70     DDDR-40     Total  
Number of Participants  
[units: participants]
 		  475     488     470     1433  
Age  
[units: years]
Mean ± Standard Deviation 		  67.3  ± 11.4     67.5  ± 10.4     66.7  ± 11.6     67.2  ± 11.1  
Gender  
[units: participants]
 		       
Female     165     156     165     486  
Male     310     332     305     947  



  Outcome Measures
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1.  Primary:   Clinical Composite Score   [ Time Frame: From randomization (6-weeks) through 12-month visit ]
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2.  Secondary:   Change in Quality of Life   [ Time Frame: From randomization (6-weeks) through 12-month visit ]
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3.  Secondary:   Change in Self Assessed Physical Activity   [ Time Frame: From randomization (6-weeks) through 12-month visit ]
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Measure Type Secondary
Measure Title Change in Self Assessed Physical Activity
Measure Description Physical activity was assessed using the Physical Activity Scale of the Elderly (PASE) questionnaire for those patients with paired data available at the 6 week and 12 month visits. The PASE is designed to assess physical activity in older persons. The total PASE score was computed by multiplying the amount of time spent in each activity (hours/week) or participation (yes/no) in an activity by empirically derived item weights and summing over all activities. PASE scores for this study ranged from 0 to 756 with higher scores indicating more physical activity.
Time Frame From randomization (6-weeks) through 12-month visit  
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.
Physical activity was assessed using the Physical Activity Scale for the Elderly and was analyzed for those patients with paired data available at the 6 week and 12 month visit. Patients were analyzed in their randomized groups. Postive values for changes denote improvements.

Reporting Groups
  Description
DDD-40 Atrial Tracking (atrial rate support above 40 bpm)
DDD-70 Atrial Rate Support (atrial rate support above 70 bpm)
DDDR-40 Rate Adaptive Pacing (atrial rate support above 40 bpm with rate responsive pacing)

Measured Values
    DDD-40     DDD-70     DDDR-40  
Number of Participants Analyzed  
[units: participants]
 		  339     362     348  
Change in Self Assessed Physical Activity  
[units: units on a scale]
Mean ± Standard Deviation 		  12.45  ± 78.62     22.62  ± 88.86     25.69  ± 92.41  


Statistical Analysis 1 for Change in Self Assessed Physical Activity
Groups [1] DDD-40 vs. DDD-70
Method [2] t-test, 2 sided
P Value [3] 0.11
Mean Difference (Final Values) [4] -10.17
Standard Error of the mean ± 6.35
95% Confidence Interval ( -22.65 to 2.30 )
[1] Additional details about the analysis, such as null hypothesis and power calculation:
  Compare the difference in the changes in physical activity scores between groups using a t-test.
[2] Other relevant information, such as adjustments or degrees of freedom:
  No text entered.
[3] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  No text entered.
[4] Other relevant estimation information:
  No text entered.

Statistical Analysis 2 for Change in Self Assessed Physical Activity
Groups [1] DDD-40 vs. DDDR-40
Method [2] t-test, 2 sided
P Value [3] 0.04
Mean Difference (Final Values) [4] -13.24
Standard Error of the mean ± 6.55
95% Confidence Interval ( -26.11 to -0.37 )
[1] Additional details about the analysis, such as null hypothesis and power calculation:
 

Compare the difference in the changes in physical activity scores between groups using a t-test.

To adjust for multiple comparisons, an alpha level of 0.025 should be used to deem significance.
[2] Other relevant information, such as adjustments or degrees of freedom:
  No text entered.
[3] Additional information, such as whether or not the p-value is adjusted for multiple comparisons and the a priori threshold for statistical significance:
  No text entered.
[4] Other relevant estimation information:
  No text entered.




  Serious Adverse Events
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  Other Adverse Events
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  More Information
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Certain Agreements:  
Principal Investigators are NOT employed by the organization sponsoring the study.
There IS 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.
The agreement is:
unchecked The only disclosure restriction on the PI is that the sponsor can review results communications prior to public release and can embargo communications regarding trial results for a period that is less than or equal to 60 days. The sponsor cannot require changes to the communication and cannot extend the embargo.
unchecked The only disclosure restriction on the PI is that the sponsor can review results communications prior to public release and can embargo communications regarding trial results for a period that is more than 60 days but less than or equal to 180 days. The sponsor cannot require changes to the communication and cannot extend the embargo.


Limitations and Caveats
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
Lack of longer-term follow-up. Single blind design where investigator could be aware of treatment assignment. Two conservative atrial support pacing modes; results should not be extended to substantially more atrial pacing and higher heart rates.  


Results Point of Contact:  
Name/Title: Kira Stolen
Organization: Clinical Affairs
phone: 1 800 CARDIAC
e-mail: cshd@bsci.com


Publications:

Publications automatically indexed to this study:


Responsible Party: Boston Scientific Corporation
ClinicalTrials.gov Identifier: NCT00146848     History of Changes
Other Study ID Numbers: CR-CA-100604-H, PEGASUS
Study First Received: September 2, 2005
Results First Received: February 28, 2010
Last Updated: December 20, 2011
Health Authority: United States: Institutional Review Board