Trial Outcomes & Findings for Reducing Episodes by Septal Pacing Efficacy Confirmation Trial (RESPECT) (NCT NCT00289289)

Last Updated: 2012-08-08

Results Overview

The frequency of symptomatic atrial tachycardia/atrial fibrillation (AT/AF) episodes as measured by the Patient Assistant and retrieved from save-to-disk information. For each subject and programming period (3-9 month period and 9-15 month period), the rate of symptomatic AT/AF episodes was computed by summing the total number of Patient Assistant activations during device recorded AT/AF episodes divided by months of device follow-up in each study period. Within each subject, the ON minus OFF difference in rate of symptomatic AT/AF was computed

Recruitment status

COMPLETED

Study phase

Target enrollment

400 participants

Primary outcome timeframe

6-months (per Intervention)

Results posted on

2012-08-08

Participant Flow

The first study implant occurred on 13 February 2004 and the last study visit occurred on 10 November 2010

At the 3-month post-implant follow-up visit, all implanted subjects with documented Atrial tachycardia/Atrial fibrillation episode(s) during the 3-month observation period were eligible for randomization. Subjects with no documented Atrial tachycardia/Atrial fibrillation episodes were followed as part of the non-randomized group.

Participant milestones

Participant milestones
Measure	On-Off Subjects have intervention pacing features turned On according to randomization assignment in the first crossover period then Off in the second period.	Off-On Subjects have intervention pacing features turned Off according to the randomization assignment for the first crossover period and then On in the second period.	Non-Randomized Group Subjects exiting prior to the 3-month randomization visit or subjects with no AT/AF burden during the 3-month observation period
Overall Study STARTED	132	124	144
Overall Study COMPLETED	113	114	95
Overall Study NOT COMPLETED	19	10	49

Reasons for withdrawal

Reasons for withdrawal
Measure	On-Off Subjects have intervention pacing features turned On according to randomization assignment in the first crossover period then Off in the second period.	Off-On Subjects have intervention pacing features turned Off according to the randomization assignment for the first crossover period and then On in the second period.	Non-Randomized Group Subjects exiting prior to the 3-month randomization visit or subjects with no AT/AF burden during the 3-month observation period
Overall Study Withdrawal by Subject	5	3	15
Overall Study Lost to Follow-up	1	0	1
Overall Study Death	4	2	5
Overall Study No implant attempted	0	0	1
Overall Study Physician Decision	1	0	6
Overall Study Non-study device implanted	2	1	3
Overall Study Did not meet inclusion/exclusion	0	0	6
Overall Study Other Exit Reason	6	4	12

Baseline Characteristics

Reducing Episodes by Septal Pacing Efficacy Confirmation Trial (RESPECT)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	On-Off n=132 Participants Subjects have intervention pacing features turned On according to randomization assignment in the first crossover period then Off in the second period.	Off-On n=124 Participants Subjects have intervention pacing features turned Off according to the randomization assignment for the first crossover period and then On in the second period.	Non-Randomized Group n=144 Participants Subjects exiting prior to the 3-month randomization visit or subjects with no AT/AF burden during the 3-month observation period	Total n=400 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants	0 Participants n=4 Participants
Age, Categorical Between 18 and 65 years	25 Participants n=5 Participants	30 Participants n=7 Participants	27 Participants n=5 Participants	82 Participants n=4 Participants
Age, Categorical >=65 years	107 Participants n=5 Participants	94 Participants n=7 Participants	117 Participants n=5 Participants	318 Participants n=4 Participants
Age Continuous	73.0 years STANDARD_DEVIATION 9.9 • n=5 Participants	70.6 years STANDARD_DEVIATION 9.3 • n=7 Participants	72.4 years STANDARD_DEVIATION 9.2 • n=5 Participants	72.0 years STANDARD_DEVIATION 9.5 • n=4 Participants
Sex: Female, Male Female	82 Participants n=5 Participants	60 Participants n=7 Participants	80 Participants n=5 Participants	222 Participants n=4 Participants
Sex: Female, Male Male	50 Participants n=5 Participants	64 Participants n=7 Participants	64 Participants n=5 Participants	178 Participants n=4 Participants
Region of Enrollment United States	125 participants n=5 Participants	118 participants n=7 Participants	139 participants n=5 Participants	382 participants n=4 Participants
Region of Enrollment Canada	7 participants n=5 Participants	6 participants n=7 Participants	5 participants n=5 Participants	18 participants n=4 Participants

PRIMARY outcome

Timeframe: 6-months (per Intervention)

Population: Patient Assistant data which contained markers for symptomatic atrial tachycardia or atrial fibrillation episodes obtained from save-to-disk data was required from both randomized follow-up periods (3-9 months and 9-15 months) for the subject to be included in the primary ITT analysis.

Outcome measures

Outcome measures
Measure	Intervention Pacing Features Programmed ON n=222 Participants 6-month period subjects had the intervention pacing features programmed ON. For subjects randomized to the ON-OFF group, this was the 3-9 month post-implant period. For subjects randomized to the OFF-ON group this was the 9-15 month post-implant period.	Intervention Pacing Features Programmed OFF n=222 Participants 6-month period subjects had the intervention pacing features programmed OFF. For subjects randomized to the ON-OFF group, this was the 9-15 month post-implant period. For subjects randomized to the OFF-ON group this was the 3-9 month post-implant period.
Rate of Symptomatic Atrial Tachycardia/Atrial Fibrillation Episodes Per Subject Per Month	2.0 Episodes per subject per month Standard Deviation 4.8	1.8 Episodes per subject per month Standard Deviation 5.2

SECONDARY outcome

Timeframe: 6 months (per Intervention)

Population: Of the 256 randomized subjects only 211 completed the AF symptom checklist at both the 9-month and 15-month visit. Since this was a crossover study, data from both visits was required for the subject to be included in the analysis

The AF symptom checklist (SCL) is a 16 item questionnaire measuring the frequency of 16 arrhythmia related symptoms such as tiredness/lack of energy, heart fluttering/skipping, heart racing, lightheadedness, etc. Symptom frequency is rated as never (scored as 0), rarely (scored as 1), sometimes (scored as 2), often (scored as 3), and always (scored as 4). Scores are summed across each subject and timepoint and range from 0 (no symptoms) to 64 (always symptoms). For each subject the 9 month and 15 months scores were summed respectively and ON minus OFF differences computed.

Outcome measures

Outcome measures
Measure	Intervention Pacing Features Programmed ON n=211 Participants 6-month period subjects had the intervention pacing features programmed ON. For subjects randomized to the ON-OFF group, this was the 3-9 month post-implant period. For subjects randomized to the OFF-ON group this was the 9-15 month post-implant period.	Intervention Pacing Features Programmed OFF n=211 Participants 6-month period subjects had the intervention pacing features programmed OFF. For subjects randomized to the ON-OFF group, this was the 9-15 month post-implant period. For subjects randomized to the OFF-ON group this was the 3-9 month post-implant period.
Evaluate Subject Symptoms With the Atrial Fibrillation (AF) Symptom Checklist	12.0 Scores on a scale Interval 0.0 to 41.0	13.0 Scores on a scale Interval 0.0 to 41.0

SECONDARY outcome

Timeframe: 6 months (per Intervention)

Population: All randomized subjects with follow-up during intervention pacing feature programming period.

The dates of cardioversions attempted for atrial fibrillation (AF) since the previous study visit were collected at the 3, 9, and 15 month follow-up visits. For each randomized subject, the months to first attempted cardioversion during each randomized study period (3-9 months and 9-15 months) was determined. A repeated measures Cox proportional hazards model was used to compare the attempted cardioversion rate during periods of time where the pacing features were programmed ON versus OFF.

Outcome measures

Outcome measures
Measure	Intervention Pacing Features Programmed ON n=249 Participants 6-month period subjects had the intervention pacing features programmed ON. For subjects randomized to the ON-OFF group, this was the 3-9 month post-implant period. For subjects randomized to the OFF-ON group this was the 9-15 month post-implant period.	Intervention Pacing Features Programmed OFF n=245 Participants 6-month period subjects had the intervention pacing features programmed OFF. For subjects randomized to the ON-OFF group, this was the 9-15 month post-implant period. For subjects randomized to the OFF-ON group this was the 3-9 month post-implant period.
Time to First Cardioversion (Changing an Abnormal Heart Rhythm Into a Normal One by Using Either Medication or Electrical Shock)	2.1 Months Standard Deviation 1.7 • Interval to 1.73	3.3 Months Standard Deviation 1.6

SECONDARY outcome

Timeframe: 6 months (per Intervention)

Population: Of the 256 randomized to ON-OFF or OFF-ON programming, 225 had device data necessary for computing AT/AF burden in both randomized study periods.

AT/AF burden is defined as the sum of the duration of all atrial arrhythmias as recorded by the device divided by the device follow-up time during the programming period expressed as hours of atrial arrhythmia per day.

Outcome measures

Outcome measures
Measure	Intervention Pacing Features Programmed ON n=225 Participants 6-month period subjects had the intervention pacing features programmed ON. For subjects randomized to the ON-OFF group, this was the 3-9 month post-implant period. For subjects randomized to the OFF-ON group this was the 9-15 month post-implant period.	Intervention Pacing Features Programmed OFF n=225 Participants 6-month period subjects had the intervention pacing features programmed OFF. For subjects randomized to the ON-OFF group, this was the 9-15 month post-implant period. For subjects randomized to the OFF-ON group this was the 3-9 month post-implant period.
Atrial Tachycardia/Atrial Fibrillation (AT/AF) Burden	4.0 hours per day Standard Deviation 6.8	4.1 hours per day Standard Deviation 7.2

Adverse Events

On-Off

Serious events: 7 serious events

Other events: 0 other events

Deaths: 0 deaths

Off-On

Serious events: 8 serious events

Other events: 0 other events

Deaths: 0 deaths

Non-Randomized Group

Serious events: 4 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	On-Off n=132 participants at risk Subjects have intervention pacing features turned On according to randomization assignment in the first crossover period then Off in the second period.	Off-On n=124 participants at risk Subjects have intervention pacing features turned Off according to the randomization assignment for the first crossover period and then On in the second period.	Non-Randomized Group n=144 participants at risk Subjects exiting prior to the 3-month randomization visit or subjects with no AT/AF burden during the 3-month observation period
General disorders RV Lead Dislodgement	0.76% 1/132 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	2.4% 3/124 • Number of events 3 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/144 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Other System Effect	0.00% 0/132 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.81% 1/124 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.69% 1/144 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders RA Lead Dislodgement	0.00% 0/132 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.81% 1/124 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.69% 1/144 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Atrial Fibrillation	0.76% 1/132 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/124 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/144 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Atrial Fibrillation/Gastrointeritis	0.00% 0/132 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.81% 1/124 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/144 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Device Electrical Reset	0.00% 0/132 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.81% 1/124 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/144 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Dizziness	0.00% 0/132 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/124 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.69% 1/144 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Failure to Capture	0.76% 1/132 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/124 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/144 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Hemo/pneumothorax	0.76% 1/132 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/124 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/144 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Other Component Failure	0.76% 1/132 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/124 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/144 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Pacemaker Syndrome	0.00% 0/132 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.81% 1/124 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/144 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Pocket Erosion	0.76% 1/132 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/124 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/144 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders Pulmonary Edema	0.76% 1/132 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/124 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/144 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.
General disorders RV and RA Lead Dislodgement	0.00% 0/132 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.00% 0/124 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.	0.69% 1/144 • Number of events 1 • From enrollment through the 15-month study visit Only serious adverse events when information reasonably suggested that a device had or may have caused the adverse event were collected.

Other adverse events

Adverse event data not reported

Additional Information

Jen Lahr

Medtronic CRDM Clinical

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Restriction type: OTHER