Cardiac resynchronization therapy using pacemakers vs defibrillators in patients with nonischemic cardiomyopathy: The United States experience from 2007 to 2014

Abstract

The impact of implantable defibrillator therapy on outcomes of patients with nonischemic cardiomyopathy (NICM) who receive a cardiac resynchronization therapy (CRT) device is controversial. The purpose of this study was to examine the outcomes of NICM patients who receive a CRT-pacemaker (CRT-P) vs CRT-defibrillator (CRT-D). Using 2007-2014 claims data for a 5% random sample of Medicare beneficiaries, we followed patients with NICM who received a CRT device (1236 CRT-P, 4359 CRT-D), excluding those with a prior history of ventricular arrhythmias with a primary outcome of all-cause mortality and secondary outcomes including time to first cardiac hospitalization and total medical costs. Propensity score matching and Cox proportional hazard models were used to balance patient characteristics between treatment groups. At 5 years, 2007 patients (36%) died and 3809 (68%) were hospitalized for any reason, whereas 2504 (45%) were hospitalized for cardiac causes. In the propensity score matched sample, the time to all-cause mortality (hazard ratio [HR] 0.90; 95% confidence interval [CI] 0.74-1.09), any hospitalization (HR 1.13; 95% CI 0.98-1.30), and cardiac hospitalization (HR 0.98; 95% CI0.83-1.17) did not differ between matched CRT-P and CRT-D recipients. However, CRT-P recipients had significantly lower medical costs (difference ∼$20,000) and cardiac-related medical costs at 12 and 24 months. Although more expensive, defibrillator therapy is not associated with prolonged survival or decreased risk of hospitalization in CRT recipients with NICM. These results suggest that in patients with NICM and no previous history of ventricular arrhythmias, CRT-P devices should be considered. These findings have important clinical and economic implications.