Cardiac resynchronization therapy delays heart transplantation in patients with end-stage heart failure and mechanical dyssynchrony

Background: Cardiac dyssynchrony is frequent in advanced heart failure, and cardiac resynchronization therapy (CRT) may offer an alternative to heart transplantation. We aimed to investigate the impact of CRT on freedom from Tx and death in transplant candidates with end-stage heart failure. Methods: Over a period of 2 years, 46 consecutive patients with refractory congestive heart failure due to dilated cardiomyopathy were referred for heart transplant evaluation. Patients with cardiac dyssynchrony > 107 milliseconds according to tissue Doppler imaging (TDI) or QRS duration > 150 milliseconds were treated with CRT (CRT group, n = 24), whereas patients without dyssynchrony were not treated (non-CRT group, n = 22). Results: At baseline, both groups showed similar hemodynamic and functional parameters, including ejection fraction (19 +/- 10% vs 21 +/- 12%, not statistically significant [NSI) and VO(2)max (11.9 +/- 2.0 vs 12.0 +/- 1.8 ml/kg/min, NS). After a follow-up of 488 +/- 346 days, cumulative survival with freedom from transplantation and death was higher in CRT vs non-CRT patients (92% vs 39%; P < 0.001). CRT patients showed a decrease in New York Heart Association (NYHA) class from 3.2 +/- 1.1 to 2.2 +/- 0.9 (P = 0.003) and an increase in VO(2)max from 11.9 +/- 2.0 to 13.1 +/- 1.8 ml/kg/min (1) 0.02), and 71% (17 of 24) of these patients were successfully removed from the waiting list. Conclusions: in heart transplant candidates with significant dyssynchrony, CRT delays heart transplantation and improves NYHA class and exercise capacity. For these patients, CRT should be considered before heart transplantation.