Effect of physiscal training on exercise capacity, gas exchange and N-terminal pro-brain natriuretic peptide levels in patients with chronic heart failure

BACKGROUND: Decreased exercise capacity is the main factor restricting the daily life of patients with chronic heart failure. N-terminal pro-brain natriuretic peptide (NT pro-BNP) is strongly related to the severity of and is an independent predictor of outcome in chronic heart failure. DESIGN: The study aimed to evaluate the effect of exercise training on functional capacity and on changes in NT pro-BNP levels and to assess the effect of exercise training on quality of life. MATERIALS AND METHODS: Sixty patients (45 men/15 women, mean age 52.7 years; +/-5.3 SD), with stable heart failure (45 ischaemic/hypertensive and 15 idiopathic patients), in New York Heart Association (NYHA) functional class II (n=35) to III (n=25), with an ejection fraction less than 40%, were randomly assigned to a training (n=30) and a control group (n=30). The training group (30 patients) performed 3 months of supervised physical training programme using a bicycle ergometer for 30 min three times a week at a load corresponding to 60-70% of their oxygen consumption (VO2) peak. The control group did not change their previous physical activity. A graded maximal exercise test with respiratory gas analysis and an endurance test with constant workload corresponding to 85% of the peak oxygen load at the baseline and after 3 months were performed, and at the same times NT pro-BNP levels were measured. RESULTS: The exercise capacity increased from 15.8 (+/-2.3 SD) to 29.9 (+/-2.1 SD) min (P<0.0001) and the peak VO2 tended to improve from 14.5 (+/-1.4 SD) to 17.7 (+/-2.6 SD) ml/kg per min (P<0.0001) during the supervised training period. VO2 at the anaerobic threshold increased from 12.9 (+/-1.0 SD) to 15.5 (+/-1.7 SD) ml/kg per min (P