The gain of peak VO2 after exercise training has prognostic value in CHF patients. The predictive factors influencing this response remain debated. As oxygen pulse is correlated with the stroke volume, it could reflect cardiac adaptation during exercise. The aim of this study is to evaluate the cardiac participation in benefits of exercise training (ET).

We included prospectively 53 CHF patients (mean age: 57± 12 years, LVEF 29±6%) who underwent two cardiopulmonary exercises (CPX): before and after 20 endurance exercise training sessions. We analysed for the two CPX heart rate, workload, VO2, oxygen pulse and calculated stroke volume and cardiac output at rest, anaerobic threshold (AT) and peak exercise. We measured BNP levels before and after the exercise training program. Patients were considered as responders if the gain of peak VO2 was >10%.

Mean change in peak VO2 after exercise training is 17% for global population, 36% for responders (n=27) and – 4% for non responders (n=26). At baseline, responder patients have a lower worload at AT and at peak exercise (52.6±19 vs 62.2±17 watts p: 0.035 and 68.9±28 vs 86.6±27 watts p:0.035); a lower oxygen uptake (14.8±4.8 vs 17.5±4,6ml/kg/min p: 0.04), a chronotropic incompetence (max heart rate 99.8±19.8 vs 116±25 b/min p:0.01), a lower maximal cardiac output (6.6±2.5 vs 8.0±2,3l/min p:0.019) and a higher BNP serum level (median 506 vs 279 pg/l p:0.019). However oxygen pulse trends or left ventricular function do not influence changes in peak VO2 at any time and regardless of the training type (continuous vs interval training).

Cardiac adaptations in CHF patients do not seem to play major role in the response to exercise. Benefits of exercise training on exercise tolerance in CHF patients are mainly due to peripheral improvements.