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.

Endothelial dysfunction has been suggested as a potential mechanism contributing to the development and progression of heart failure (HF). Levels of circulating endothelial cells (CECs), endothelial progenitor cells (EPCs), and hematopoietic stem and progenitor cells (HSPCs) have been recognized as useful markers of vascular damage and endothelial repair in response to tissue injury. To evaluate the circulating levels of EPCs, CECs, and HSPCs among patients with HF with reduced ejection fraction (HFrEF). In 82 individuals (42 patients with HFrEF and 42 age-matched subjects without established cardiovascular disease), peripheral blood was drawn and levels of EPCs, CECs, and HSPCs were quantified by flow cytometry. Patients with HFrEF showed lower levels of circulating EPCs (5.28 × 10^-3 ± 6.83 × 10^-4% vs. 7.76 × 10^-3 ± 4.91 × 10^-4%, p ≤0.001) and CECs (5.11 × 10^-3 ± 7.87 × 10^-4% vs. 6.51 × 10^-3 ± 5.21 × 10^-4%, p = 0.005) when compared to the age-matched group. Circulating levels of HSPCs were not significantly different between groups (p = 0.590). Additionally, the number of EPCs and CECs was significantly higher in HFrEF patients with overweight/obesity (n = 24) compared to patients with normal weight (n = 17). Circulating levels of EPCs and CECs were significantly decreased in patients with HFrEF in comparison to age-matched subjects without established cardiovascular disease, suggesting that the levels of CECs and EPCs may be potential biomarkers of the cellular response to vascular injury in patients with HFrEF.

It is widely accepted that exercise training has beneficial effects on vascular health. Although a dose-dependent relation has been suggested, little is known about the effects of different exercise durations on endothelial markers. This study aimed to assess the effect of single exercise sessions with different durations in the circulating levels of endothelial progenitor cells (EPCs) and endothelial cells (CECs) among adults with cardiovascular risk factors. Ten participants performed two multicomponent exercise sessions, one week apart, lasting 30 and 45 min (main exercise phase). Before and after each exercise session, blood samples were collected to quantify EPCs and CECs by flow cytometry. The change in EPCs was significantly different between sessions by 3.0% (95% CI: 1.3 to 4.7), being increased by 1.8 ± 1.7% (p = 0.009) in the 30 min session vs. −1.2 ± 2.0% (p > 0.05) in the 45 min session. No significant change was observed in CECs [−2.0%, 95%CI: (−4.1 to 0.2)] between the sessions. In conclusion, a multicomponent exercise session of 30 min promotes an acute increase in the circulating levels of EPCs without increasing endothelial damage (measured by the levels of CECs) among adults with cardiovascular risk factors.

The impact of exercise on the levels of endothelial progenitor cells (EPCs), a marker of endothelial repair and angiogenesis, and circulating endothelial cells (CECs), an indicator of endothelial damage, in heart failure patients is largely unknown. This study aims to evaluate the effects of a single exercise bout on the circulating levels of EPCs and CECs in heart failure patients. Thirteen patients with heart failure underwent a symptom-limited maximal cardiopulmonary exercise test to assess exercise capacity. Before and after exercise testing, blood samples were collected to quantify EPCs and CECs by flow cytometry. The circulating levels of both cells were also compared to the resting levels of 13 volunteers (age-matched group). The maximal exercise bout increased the levels of EPCs by 0.5% [95% Confidence Interval, 0.07 to 0.93%], from 4.2 × 10⁻³ ± 1.5 × 10⁻³% to 4.7 × 10⁻³ ± 1.8 × 10⁻³% (p = 0.02). No changes were observed in the levels of CECs. At baseline, HF patients presented reduced levels of EPCs compared to the age-matched group (p = 0.03), but the exercise bout enhanced circulating EPCs to a level comparable to the age-matched group (4.7 × 10⁻³ ± 1.8 × 10⁻³% vs. 5.4 × 10⁻³ ± 1.7 × 10⁻³%, respectively, p = 0.14). An acute bout of exercise improves the potential of endothelial repair and angiogenesis capacity by increasing the circulating levels of EPCs in patients with heart failure.