Effects of cardiac resynchronization therapy with or without a defibrillator on survival and hospitalizations in patients with New York Heart Association class IV heart failure.

Background: Cardiac resynchronization therapy (CRT) alone or combined with an implantable defibrillator (CRT-D) has been shown to improve exercise capacity and quality of life and to reduce heart failure (HF) hospitalizations and mortality in patients with New York Heart Association (NYHA) class III and IV HF. There is concern that the device procedure may destabilize these very ill class IV patients. We sought to examine the outcomes of NYHA class IV patients enrolled in the Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION) trial to assess the potential benefits of CRT and CRT-D.

Methods And Results: The COMPANION trial randomized 1520 patients with NYHA class III and IV HF to optimal medical therapy, CRT, or CRT-D. In the class IV patients (n=217), the primary end point of time to death or hospitalization for any cause was significantly improved by both CRT (hazard ratio [HR], 0.64; 95% CI, 0.43 to 0.94; P=0.02) and CRT-D (HR, 0.62; 95% CI, 0.42 to 0.90; P=0.01). Time to all-cause death and HF hospitalization was also significantly improved in both CRT (HR, 0.57; 95% CI, 0.37 to 0.87; P=0.01) and CRT-D (HR, 0.49; 95% CI, 0.32 to 0.75; P=0.001) Time to all-cause death trended to an improvement in both CRT (HR, 0.67; 95% CI, 0.41 to 1.10; P=0.11) and CRT-D (HR, 0.63; 95% CI, 0.39 to 1.03; P=0.06). Time to sudden death appeared to be significantly reduced in the CRT-D group (HR, 0.27; 95% CI, 0.08 to 0.90; P=0.03). There was a nonsignificant reduction in time to HF deaths for both CRT (HR, 0.68; 95% CI, 0.34 to 1.37; P=0.28) and CRT-D (HR, 0.79; 95% CI, 0.41 to 1.52; P=0.48).

Conclusions: CRT and CRT-D significantly improve time to all-cause mortality and hospitalizations in NYHA class IV patients, with a trend for improved mortality. These devices should be considered in ambulatory NYHA class IV HF patients similar to those enrolled in COMPANION.