Morbidity and mortality in heart failure patients treated with cardiac resynchronization therapy: influence of pre-implantation characteristics on long-term outcome

Aims Cardiac resynchronization therapy (CRT) improves cardiac function, heart failure symptoms, and prognosis in selected patients. Many baseline characteristics associated with heart failure may influence prognosis after CRT. The objective of this study was to evaluate the effect of several baseline characteristics in relation to long-term prognosis in heart failure patients treated with CRT. Methods and results A total of 716 consecutive heart failure patients treated with CRT were included in an observational registry. All available data, including clinical and echocardiographic measurements, were analysed in relation to two endpoints: all-cause mortality and a combined endpoint of all-cause mortality or major cardiovascular event. Outcome data were collected by chart review, device interrogation, and telephone contact. Mean follow-up was 25 +/- 19 months. During follow-up, 141 patients (20%) died (primary endpoint). Most of these patients (61%) died due to worsening heart failure. A total of 214 patients (30%) reached the secondary endpoint. Larger left ventricular end-systolic volume, less distance covered in the 6 min walking test, poor renal function, more severe heart failure, male gender, presence of atrial fibrillation, no posterolateral left ventricular (LV) lead, and no LV dyssynchrony were associated with poor prognosis after CRT. Conclusions In this large single-centre registry, several baseline clinical and echocardiographic characteristics were associated with prognosis after CRT. Worsening heart failure was the main cause of death in heart failure patients treated with CRT.