Effects of exercise on endothelial progenitor cells in patients with cardiovascular disease: A systematic review and meta-analysis of randomized controlled trials.

The therapeutic potential of exercise training in the mobilization of endothelial progenitor cells (EPCs) into the peripheral blood in patients with cardiovascular disease is not yet clear. A systematic review and meta-analysis was performed in order to assess the effectiveness of exercise training in increasing the number of circulating EPCs in patients with cardiovascular disease. A literature search was conducted across the PubMed, Scopus, Web of Science and EBSCO databases, including the reference lists of relevant papers. The quality of randomized clinical trials was evaluated using the PEDro scale. The primary outcome data were circulating EPC levels. Six studies (236 participants) - three on heart failure (n=111), one on peripheral arterial disease (n=40) and two on coronary artery disease (n=85) - were included. There was an increase in EPC levels in the exercise training groups (effect size [ES]=0.57; 95% CI: 0.01-1.12), with considerable heterogeneity (I2=75.6%; p<0.001). In subgroup analyses, patients with heart failure showed a significant increase in EPCs in the exercise training groups (ES=0.52; 95% CI: 0.15-0.90), with low heterogeneity (I2=0.0%; p=0.648), while no significant increase (ES=0.67; 95% CI: -0.70-2.04; I2=91.2%; p<0.001) was observed in patients with arterial disease. The only study in patients with peripheral arterial disease showed a significant increase in EPC levels. This meta-analysis indicates that exercise training may be a therapeutic option to improve EPC levels and potentially to enhance endothelial function and repair in patients with heart failure.