Effect of exercise training in patients with angina with nonobstructive coronary arteries: a systematic review and meta-analysis.

Angina with nonobstructive coronary arteries (ANOCA) is a highly prevalent heart disease. The evidence on exercise training (ET) for the treatment of ANOCA, however, is still inadequate. This meta-analysis aims to provide a comprehensive assessment of the effect of ET in patients with ANOCA. Studies were searched from PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, VIP, and WanFang from inception to 15 January 2024. The quality of included studies was assessed using the Cochrane risk of bias tool. Heterogeneity among the studies was evaluated using Cochran's Q test and I2 statistic, and subgroup analysis based on gender was performed to explore potential sources of heterogeneity. A total of 12 studies were included in this meta-analysis. The pooled results showed that ET significantly increased the peak oxygen uptake (peak VO 2 ) [weighted mean difference (WMD) = 6.11, 95% confidence interval (CI): 4.73 to 7.50], left ventricular ejection fraction (WMD = 7.66, 95% CI: 5.53 to 9.78), and 6 min walking test (WMD = 55.55; 95% CI: 16.23 to 94.87). Nitric oxide (WMD = 20.18, 95% CI: 19.16 to 21.21) and peripheral arterial tonometry (WMD = 0.16, 95% CI: 0.11 to 0.21) were higher, and matrix metalloproteinase-9 (WMD = -8.02, 95% CI: -9.21 to -6.84) was lower in ET group. In conclusion, our findings indicated that ET could improve cardiopulmonary function, exercise capacity, and endothelial function, which could be recommended for the treatment of ANOCA patients.