Cardiac stem cell therapy following myocardial infarction: a systematic review and meta-analysis of randomized controlled trials

Objectives: Myocardial infarction (MI) remains a major cause of morbidity and mortality worldwide, primarily due to irreversible cardiomyocyte injury and minimal regenerative potential. While mesenchymal and bone-marrow-derived stem cells have been widely studied, evidence for cardiac stem cells (CSCs) remains limited. This systematic review and meta-analysis evaluate the effi cacy of cardiac stem cell therapy after MI. Methods: We conducted this meta-analysis in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Eligible studies were identifi ed from electronic searches of PubMed, EBSCO, and ProQuest for randomized controlled trials (RCTs) evaluating the effi cacy of cardiac stem cell therapy after MI. The random effect analysis was performed using R v4.4.1. Results: Four randomized controlled trials comprising 329 participants were included. At six months, cardiac stem cell therapy was associated with a signifi cant reduction in scar mass (MD: -4.25 g, 95% CI: -7.16 to -1.34, p = 0.004) and infarct size (MD: -2.32%, 95% CI: -3.91 to -0.73, p = 0.004) compared with placebo. No signifi cant differences were observed in left ventricular ejection fraction (LVEF), left ventricular end-systolic volume index (LVESVi), left ventricular end-diastolic volume index (LVEDVi) at either six or twelve months, or in the 6-minute walk test at 12 months. Conclusion: Cardiac stem cell therapy after MI is associated with modest reductions in scar mass and infarct size at six months, without signifi cant improvement in global ventricular function or functional capacity up to twelve months. These fi ndings suggest that while CSCs may confer early structural benefi ts, their clinical impact remains uncertain and requires confi rmation in larger trials with longer follow-up.