Impact of rate-modulated pacing on quality of life and exercise capacity--evidence from the Advanced Elements of Pacing Randomized Controlled Trial (ADEPT).
BACKGROUND
Ninety-nine percent of pacemakers implanted in the United States include an option for rate modulation.


OBJECTIVE
The purpose of this study was to determine whether dual-chamber rate-modulated pacing, when compared with dual-chamber pacing alone, improved quality of life.


METHODS
This was a single-blind randomized controlled trial comparing dual-chamber with rate-modulated dual-chamber pacing. Patients were enrolled between January 12, 2000, and January 10, 2002, with 1-year follow-up ending December 19, 2002. The study was a U.S. multicenter trial, with 95 sites participating. All patients received a rate modulation-capable dual-chamber pacemaker for standard indications. Patients were screened with an exercise test (Chronotropic Assessment Exercise Protocol) 1 month later. One thousand two hundred seventy-three patients were enrolled; 401 proved ineligible, and 872 (68%) made up the randomized patient cohort. Randomized patients had a mean age of 71 years, 64% were men, and 64% had sinus node dysfunction. Randomization was in a factorial design to (1) dual-chamber rate-modulated pacing versus dual-chamber pacing and (2) automatic mode switching versus no automatic mode switching. The present report is limited to the comparison of rate modulation with no rate modulation (DDDR vs. DDD). The primary endpoint was the score on the Specific Activity Scale, an activity-based cardiovascular disease-specific instrument at 1 year. Secondary endpoints included 6-month treadmill time and additional cardiovascular disease-specific, and generic health-related quality-of-life instruments at 1 year.


RESULTS
At 6 months, patients with rate modulation had a higher peak exercise heart rate (rate modulation 113.3 +/- 19.6, no rate modulation 101.1 +/- 21.1; P <.0001). Total exercise time was not different between groups. At 1 year, there were no significant differences between groups with respect to Specific Activity Scale or the secondary quality-of-life endpoints.


CONCLUSIONS
We conclude that rate modulation is ineffective in improving the functional status or quality of life of patients with a bradycardia indication for dual-chamber pacing.
Lamas
Gervasio A
GA
Division of Cardiology, Mount Sinai Medical Center, Miami Beach, Florida 33140, USA. most95@aol.com
Knight
J David
JD
Sweeney
Michael O
MO
Mianulli
Marcus
M
Jorapur
Vinod
V
Khalighi
Koroush
K
Cook
James R
JR
Silverman
Russell
R
Rosenthal
Lawrence
L
Clapp-Channing
Nancy
N
Lee
Kerry L
KL
Mark
Daniel B
DB
D000368:Aged; D001919:Bradycardia / Q000517:prevention & control; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D002985:Clinical Protocols; D015331:Cohort Studies; D004867:Equipment Design; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011788:Quality of Life; D016037:Single-Blind Method