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 (LV) remodeling in selected populations with heart failure (HF). These benefits have been noted with both CRT pacemakers (CRT-P) as well as those devices with defibrillator back-up (CRT-D). However, there are little data comparing mortality between these two device types. METHODS AND RESULTS: -REVERSE was a multi-center, randomized trial of CRT among patients with mild HF. Long-term annual follow-up for 5 years was preplanned. The present analysis was confined to the 419 patients who were randomized to CRT ON. CRT-P or CRT-D devices were implanted based on national guidelines at the time of enrollment, with 74 patients receiving CRT-P devices and the remaining 345 receiving CRT-D devices. After 12 months of CRT, changes in the Clinical Composite Score, left ventricular end systolic volume index (LVESVi), 6-minute walk time and quality of life indices were similar between CRT-P and CRT-D patients. However, long term follow-up showed lower morality in the CRT-D group. Specifically, multi-variable 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 LVESVi also were also associated with better survival. CONCLUSIONS: -REVERSE demonstrated that the addition of ICD therapy to CRT is associated with improved long term survival compared with CRT pacing alone in mild HF. Clinical Trial Registration-URL: http://clinicaltrials.gov; Unique Identifier: NCT00271154.