Maintaining physical fitness of patients with chronic heart failure: a randomized controlled trial.

BACKGROUND: We aimed to compare the effects of three different training advices, after 1 year, following a 6 months supervised cardiac rehabilitation period in patients with chronic heart failure (CHF). METHODS: Sixty-nine CHF patients were randomized, at the end of their rehabilitation period, either to usual care (UC) or to UC and controlled home training (HT), prolonged supervised training (ST) or preferred training (PT). Treadmill cardio-pulmonary exercise testing was performed before rehabilitation, postrehabilitation and thereafter at 3-month intervals during the 1-year follow-up. submaximal exercise capacity [Oxygen consumption and workload at the respiratory compensation point (VO2RCP, WattRCP) and submaximal workload (SMW) efficiency (SMW/HR) at 70% of the initial maximal workload] was chosen as a primary endpoint, because health status in CHF patients depends largely on their ability to perform activities at a submaximal level. RESULTS: After 6 months of rehabilitation, the four groups (UC, HT, ST and PT) were comparable with regard to cardiac rehabilitation-derived benefit, both at the submaximal and maximal level. Although exercise capacity during follow-up declined in both UC and HT patients, ST and especially PT patients maintained and even improved VO2peak and VO2RCP. However, only PT patients managed to maintain or even increase submaximal (WattRCP and SMW/HR ratio) workload (P=0.045 and <0.0001 for interaction, respectively). Ventilatory-derived prognostic markers during treadmill cardio pulmonary exercise testing evolved similarly in the four subgroups. CONCLUSION: This study suggests that engagement in physical training of their own choice (PT), might be the optimal training modality for maintaining physical capacity in CHF patients.

Exercise capacity in chronic heart failure patients is related to active gene transcription in skeletal muscle and not apoptosis.

BACKGROUND: Muscle wasting partly explains exercise intolerance in chronic heart failure (CHF) patients. Skeletal muscle loss may result from apoptosis, and exercise training has been suggested to halt this process. The terminal deoxynucleotidyl transferase end-labeling (TUNEL) technique is frequently used to show apoptosis, but lacks specificity. METHODS AND RESULTS: Before and after 4 months exercise training, skeletal muscle biopsies of 16 CHF patients (59.4+/-2.2 years, 11 men, 50% ischemic etiology, ejection fraction 28.8+/-2.7%, 66.3+/-3.6% of predicted oxygen uptake) and eight sedentary controls were analyzed for apoptosis (TUNEL, including the stringent variant without proteinase K digestion, immunohistochemical analyses using antibodies against cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase, PARP, and active gene transcription (anti-splicing factor SC-35). The number of TUNEL-positive nuclei in CHF patients was comparable with controls (3.2+/-0.7 vs. 3.1+/-1.7/mm(2), P=0.2) and was not related to exercise parameters. With the stringent TUNEL and both immunostaining techniques, apoptosis was not detected. Co-occurrence of TUNEL and of SC-35 splicing factor suggests that at least part of TUNEL-positive nuclei is undergoing active gene transcription and therefore is not apoptotic. The SC-35-positive area correlated with % of predicted oxygen uptake (r=0.6, P=0.02), Wattmax (r=0.7, P=0.005) and VE/VCO2 slope (r=-0.6, P=0.03). At baseline, SC-35 immunoreactive area was significantly larger than in controls (P=0.001), but after exercise training, the difference was minimized (P=0.07). CONCLUSION: Skeletal muscle apoptosis in CHF patients could not be confirmed. Active gene transcription might stain false positive for apoptotic nuclei with TUNEL. The level of active gene transcription/splicing was related to exercise performance.