Effects of Exercise on Flow-Mediated Dilation in Patients with Heart Failure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This study aimed to evaluate the effects of exercise on vascular flow-mediated dilation (FMD) in patients with heart failure (HF) and to identify the optimal exercise model for this population. A comprehensive search was conducted in the Web of Science, Scopus, PubMed, Embase, and Cochrane databases, including data published up to 18 August 2025. A meta-analysis was conducted to calculate standardized mean difference (SMD) and 95% confidence interval. Eleven studies met the inclusion criteria, comprising 224 participants in the intervention groups and 185 participants in the control groups. The results demonstrated that exercise significantly improved FMD (SMD = 1.14, <i>p</i> < 0.0001). Subgroup analysis showed that aerobic exercise (SMD = 1.25, <i>p</i> < 0.0001), intervention period ≤ 8 weeks (SMD = 2.19, <i>p</i> < 0.00001) Intervention frequency > 3 times per week (SMD = 2.82, <i>p</i> < 0.00001) and each intervention duration < 60 min (SMD = 1.22, <i>p</i> = 0.01) were the most effective in improving FMD in patients with HF. This meta-analysis indicates that aerobic exercise performed more than three times per week, for sessions under 60 min and over an intervention period of up to 8 weeks, is associated with meaningful improvements in FMD in HF patients. These findings offer clear and actionable guidance for clinicians when prescribing exercise to support vascular health in this population.