The effect of endurance training on exercise capacity following cardiac resynchronization therapy in chronic heart failure patients: a pilot trial.

BACKGROUND: Both endurance training (ET) and cardiac resynchronization therapy (CRT) improve quality of life (QOL) and exercise tolerance in patients with advanced chronic heart failure (CHF). DESIGN: A randomized intervention trial to study the effect on exercise capacity of ET in addition to CRT in patients with CHF and dyssynchrony. METHODS: Seventeen patients (eight men, aged 59+/-9 years) with CHF and dyssynchrony were randomized to CRT with (n=8) or without (n=9) ET and compared with two matched control CHF groups (standard care with ET: n=9, standard care only: n=10). At baseline and after 5 months, exercise tolerance, left ventricular (LV) remodelling, QOL and NT-pro brain natriuretic peptide (NT-proBNP) levels were assessed. RESULTS: Peak oxygen consumption (VO2peak), maximal workload (Wattmax), circulatory power, LV ejection fraction, dyssynchrony and QOL improved in both CRT groups. However, the increase in VO2peak (+40% versus +16%, P=0.005), Wattmax (+43% versus +13%, P=0.0005), and circulatory power (+74% versus +32%, P=0.01), was significantly greater in the trained versus the untrained CRT patients. Comparison of the four patient groups confirmed the cumulative effects of CRT plus ET. CONCLUSIONS: ET in resynchronized CHF patients is feasible and further enhances exercise tolerance. Patients with severe CHF should be prescribed an exercise training programme after implantation in order to maximize the expected benefit.