Effect of exercise training on vascular endothelial function in patients with stable coronary artery disease: a randomized controlled trial

Background: We aim to investigate the effect of exercise training on endothelial function and exercise capacity in patients with coronary artery disease. Methods and results: A randomized, controlled trial was conducted to determine the effects of an 8-week exercise training programme (n = 32) vs. controls (n = 32) on brachial flow-mediated dilation (FMD) in patients with stable CAD. After 8 weeks, patients received exercise training had significant improvements in FMD (1.84%, p = 0.002) and exercise capacity (2.04 metabolic equivalents, p < 0.001) compared with controls. The change in FMD correlated inversely with baseline FMD (r = -0.41, p = 0.001) and positively with the increase in exercise capacity (r = 0.35, p = 0.005). After adjusting for confounders, every 1 metabolic equivalent increase in exercise capacity was associated with 0.55% increase in FMD. Furthermore, patients received exercise training had significantly increased high-density lipoprotein cholesterol and decreased diastolic blood pressure and resting heart rate compared with controls. However, exercise training did not alter high-sensitivity C-reactive protein, oxidative stress measured as superoxide dismutase and 8-isoprostane, and CD34/KDR + endothelial progenitor cell count. Subgroup analysis showed that FMD was significantly improved only in CAD patients with baseline low exercise capacity (< median value of 7.65 metabolic equivalents, p = 0.004) but not in those with normal exercise capacity. Conclusion: Exercise training improved FMD and exercise capacity in stable CAD patients independent of the changes in inflammation, oxidative stress, or endothelial progenitor cells. The beneficial effects of exercise training on FMD and exercise capacity are inter-related, and more pronounced in those with baseline impaired exercise capacity.