The therapeutic effect of mesenchymal stem cell-derived exosomes on animal models of myocardial infarction: a systematic review and meta-analysis

Mesenchymal stem cell-derived exosomes (MSC-Exos) have received extensive attention as a potential treatment for myocardial infarction (MI), but their cardioprotective mechanism has not been fully elucidated. This meta-analysis evaluated the efficacy of MSC-Exos in an animal model of MI. PubMed, Embase, and Web of Science were searched through April 22, 2026. Study quality and risk of bias were assessed. Random-effects models were used to pool heterogeneous cardiac function, apoptosis, fibrosis, and inflammatory outcomes. Subgroup analyses examined treatment- and animal-related factors associated with left ventricular ejection fraction (LVEF). Meta-regression explored sources of heterogeneity. Publication bias and robustness were evaluated using funnel plots, Egger/Begg tests, trim-and-fill analysis, and sensitivity analysis. A total of 45 articles were included. Compared with controls, the MSC-Exos group had higher LVEF (WMD = 13.90%, 95% CI: 11.78 to 16.03) and left ventricular shortening fraction(LVFS, WMD = 8.62%, 95% CI: 7.25 to 9.98), as well as lower left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic diameter (LVEDD), infarct size (IS), fibrosis area (FA), apoptosis and inflammatory cytokines levels. Subgroup analyses showed a consistent trend toward higher LVEF across experimental conditions, although heterogeneity remained high. Exploratory meta-regression identified no significant covariates, and sensitivity analyses yielded directionally consistent. results. Trim-and-fill adjustment did not alter the pooled effect, although small-study effects or publication bias could not be excluded. In animal models of MI, MSC-Exos improved cardiac function and reduced IS, FA, inflammation, and apoptosis. Differences in MSC source may partly explain the substantial heterogeneity in LVEF, while variable reporting quality and possible publication bias warrant caution. Future studies should use rigorous large-animal models, standardize exosome preparation and administration, and assess long-term safety. Not applicable.