Endothelial dysfunction in patients with chronic heart failure: systemic effects of lower-limb exercise training

OBJECTIVES We sought to analyze the systemic effects of lower-limb exercise training (ET) on radial artery endothelial function in patients with chronic heart failure (CHF). BACKGROUND Local ET has the potential to improve local endothelial dysfunction in patients with CHF. However, it remains unclear whether the systemic effects can be achieved by local ET. METHODS Twenty-two male patients with CHF were prospectively randomized to either ET on a bicycle ergometer (ET group, N = 11; left ventricular ejection fraction [LVEF] 26 ± 3%) or an inactive control group (group C, N = 11; LVEF 24 ± 2%). At the beginning of the study and after four weeks, endothelium-dependent and -independent vasodilation of the radial artery was determined by intra-arterial infusion of acetylcholine (ACh—7.5, 15 and 30 μg/min) and nitroglycerin (0.2 mg/min). The mean internal diameter (ID) of the radial artery was assessed using a high resolution ultrasound system (NIUS-02, Asulab Research Laboratories, Neuchâtel, Switzerland) with a 10-MHz probe. RESULTS After four weeks of ET, patients showed a significant increase in the baseline-corrected mean ID in response to ACh (30 μg/min), from 33 ± 10 to 127 ± 25 μm (p < 0.001 vs. control group at four weeks). In the control group, the response to ACh (30 μg/min) remained unchanged. Endothelium-independent vasodilation was similar in both groups at the beginning of the study and at four weeks. In the training group, increases in agonist-mediated, endothelium-dependent vasodilation correlated to changes in functional work capacity (r = 0.63, p < 0.05). CONCLUSIONS In patients with stable CHF, bicycle ergometer ET leads to a correction of endothelial dysfunction of the upper extremity, indicating a systemic effect of local ET on endothelial function.