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 CH F and dyssynchrony were randomized to CRT with (n = 8) or without (n = 9) ET and compared with two matched control CH F 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 (Vo(2)peak), maximal workload (Wattmax), circulatory power, LV ejection fraction, dyssynchrony and QOL improved in both CRT groups. However, the increase in Vo(2)peak (+ 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.