Cardiac Resynchronization With or Without Defibrillator in Nonischemic Cardiomyopathy: A Nationwide Cohort Study (DECIDE-CRT).

BACKGROUND: With evolving therapy for heart failure with reduced ejection fraction, the benefits of adding a defibrillator in patients undergoing cardiac resynchronization therapy (CRT) remain unclear, particularly for nonischemic cardiomyopathy (NICM). This study evaluates long-term survival among patients with NICM treated with CRT defibrillator (CRT-D) versus CRT pacemaker (CRT-P). METHODS: DECIDE-CRT (Cardiac Resynchronization With or Without Defibrillator in Non-Ischemic Cardiomyopathy) is a multicenter cohort study across 170 US Veterans Affairs hospitals. We identified patients with NICM receiving primary-prevention CRT-P or CRT-D between January 1, 2006, and December 31, 2020. Using a propensity score approach, we applied inverse probability of treatment weighting to balance baseline characteristics between the CRT-P and CRT-D groups. An inverse probability of treatment weighting-weighted Cox model estimated hazards for all-cause mortality. Secondary outcomes included generator replacement, device-related infections, hospitalization for heart failure, and ventricular arrhythmias. RESULTS: Of 16 609 CRT recipients, 3965 met NICM primary-prevention criteria (CRT-D=3158; CRT-P=807). At baseline, patients with NICM receiving CRT-P were much older, with more cardiovascular and noncardiovascular comorbidities compared with the CRT-D group. During the median follow-up of 5.2 years, the mortality rate for CRT-P versus CRT-D was 9.46 versus 9.21 per 100 person-years (RR, 0.97 [95% CI, 0.71-1.13]; P=0.66). The adjusted hazard ratio for all-cause mortality using the inverse probability of treatment weighting-Cox model was 0.90 (95% CI, 0.71-1.13; P=0.34). There was no difference in adjusted hazard for heart failure hospitalization (hazard ratio, 1.27 [95% CI, 0.86-1.87]), while the CRT-D group had higher rates of generator replacement and device-related infections. CONCLUSIONS: This nationwide observational study from the Veterans Affairs Health system did not demonstrate a clear survival advantage with the addition of a defibrillator among patients with NICM receiving CRT although residual confounding cannot be excluded. Given the uncertainty surrounding the incremental benefit of the defibrillator in this setting, a randomized trial is needed to test the incremental value of CRT-D over CRT-P in NICM.