Cardiac resynchronization therapy outcomes in patients with chronic heart failure

AIMS: Cardiac resynchronization therapy (CRT) for chronic heart failure with left ventricular systolic dysfunction (LVSD) consistently improves survival against optimal medical therapy alone. Limited data exist comparing the outcomes between CRT with pacemaker (CRT-P) and with defibrillator (CRT-D). We aimed to investigate the long-term prognosis of patients who received CRT-P or CRT-D. METHODS AND RESULTS: Data were prospectively collected from consecutive patients with standard indications for CRT, who were implanted at a single large tertiary centre between 2008 and 2012. All-cause mortality was compared between those patients who received either CRT-P or CRT-D. A subgroup analysis was performed in patients with ischaemic cardiomyopathy. During the period in question, 795 patients received CRT devices: 544 (68.4%) CRT-P and 251 (31.6%) CRT-D. The mean follow-up was 1072 ± (SD 556) days. Overall, there was no survival benefit in those patients implanted with a CRT-D compared with CRT-P (hazard ratio 1.09, 95% confidence interval 0.84-1.41, P = 0.51). In patients with ischaemic chronic heart failure [n = 530 (66.7%)], there was a trend for improved survival with CRT-D; however, this was not significant after adjustment. In a subgroup analysis, there were no differences in mode-specific mortality in those patients implanted with CRT-D compared with CRT-P. CONCLUSION: In this large consecutive patient cohort, we did not find a survival benefit of CRT-D compared with CRT-P. Patients indicated for CRT devices may not reliably benefit from the addition of a defibrillator.