Very long term follow-up of cardiac resynchronization therapy: clinical outcome and predictors of mortality.

Background: Cardiac resynchronization therapy (CRT) improves symptoms, left ventricular ejection fraction (LVEF) and survival in patients with heart failure and wide QRS, however, long term clinical outcome is unknown.

Aims: To identify predictors of mortality and evaluate the effects of CRT after long term follow-up.

Methods: Consecutive patients treated with CRT between 1997 and 2002 were included. We collected clinical information from patient files. Patients who were still alive underwent echocardiography and clinical evaluation.

Results: We included 179 patients (median age 65.5 years, 144 male). Median follow-up for survival was 4.0 years. Mortality at one and five years was 15% and 53%, respectively. Predictors of mortality were, ischaemic heart disease (IHD), higher NYHA class and lower LVEF (<22.5%) at baseline, and no improvement in NYHA class at early follow-up. NYHA class remained stable from early to long term follow-up after a median of 5.1 years. In patients with non-IHD median LVEF increased significantly from early to long term follow-up (39% vs. 50% p=0.007).

Conclusion: Predictors of mortality in patients with CRT are IHD, lower LVEF and higher NYHA class at baseline, and no symptomatic response to CRT. After 5 years follow-up, clinical effects are sustained, and in patients with non-IHD further improvements in LVEF are observed.