Implantable Defibrillators Improve Survival in Patients With Mildly Symptomatic Heart Failure Receiving Cardiac Resynchronization Therapy

Abstract

Background— Cardiac resynchronization therapy (CRT) decreases mortality, improves functional status, and induces reverse left ventricular remodeling in selected populations with heart failure. These benefits have been noted with both CRT-pacemakers as well as those devices with defibrillator backup (CRT-D). However, there are little data comparing mortality between these 2 device types. Methods and Results— REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) was a multicenter, randomized trial of CRT among patients with mild heart failure. Long-term annual follow-up for 5 years was preplanned. The present analysis was confined to the 419 patients who were randomized to active CRT group. CRT-pacemakers or CRT-D devices were implanted based on national guidelines at the time of enrollment, with 74 patients receiving CRT pacemaker devices and the remaining 345 patients receiving CRT-D devices. After 12 months of CRT, changes in the clinical composite score, left ventricular end systolic volume index, 6-minute walk time, and quality of life indices were similar between CRT pacemaker and CRT-D patients. However, long-term follow-up showed lower morality in the CRT-D group. Specifically, multivariable analysis showed that CRT-D (hazard ratio, 0.35; P =0.003) was a strong independent predictor of survival. Female sex, longer unpaced QRS duration, and smaller baseline left ventricular end systolic volume index also were also associated with better survival. Conclusions— REVERSE demonstrated that the addition of implantable cardioverter-defibrillator therapy to CRT is associated with improved long-term survival compared with CRT pacing alone in mild heart failure. Clinical Trial Registration— URL: http://clinicaltrials.gov . Unique Identifier: NCT00271154.