LAUSR

Objective The gain of peak VO 2 after exercise training has prognostic value in cardiac heart failure (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 function in benefits of exercise training (ET). Material/patients and methods 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 analyzed for the two CPX heart rate, workload, VO 2 , 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 VO 2 was > 10%. Results Mean change in peak VO 2 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 workload at AT and at peak exercise (52.6 ± 19 vs. 62.2 ± 17 W, P  = 0.035 and 68.9 ± 28 vs. 86.6 ± 27 W, P  = 0.035); a lower peak oxygen uptake (14.8 ± 4.8 vs. 17.5 ± 4.6 mL/kg/min, P  = 0.04), a chronotopic incompetence (max heart rate 99.8 ± 19.8 vs. 116 ± 2 beats/min, P  = 0.01), a lower maximal cardiac output (6.6 ± 2.5 vs. 8.0 ± 2.3 L/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). Discussion – conclusion Cardiac adaptations in CHF patients do not seem to play a major role in the response to exercise. Benefits of exercise training on exercise tolerance in CHF patients are mainly due to peripheral improvements.