Cardiology · Medical Literature
Efficacy and Safety of Intracoronary Mesenchymal Stem Cell Administration in ST-Segment Elevation Acute Myocardial Infarction: A Meta-Analysis of Randomized Controlled Trials.
Abstract
ST-segment elevation myocardial infarction (STEMI) remains a major cause of cardiovascular mortality and morbidity worldwide. Despite advances in reperfusion therapy, many patients still develop irreversible myocardial injury and adverse ventricular remodeling. Intracoronary mesenchymal stem cell (MSC) administration has been investigated as a potential therapeutic approach, but clinical evidence remains inconsistent. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing intracoronary MSC administration with standard care in STEMI patients. Databases were searched from inception through February 2026. Eight RCTs involving 796 patients were identified, and seven trials with 400 patients were included in the quantitative analysis after excluding one study under Expression of Concern. MSC administration significantly improved ΔLVEF (I2 = 44.6%, p = 0.108; WMD = 3.18, 95% CI: 1.52-4.83, p < 0.001). No significant differences were detected in rehospitalization for heart failure (I2 = 0.0%, p = 0.592; RR = 1.14, 95% CI: 0.36-3.61, p = 0.831), all-cause mortality (I2 = 0.0%, p = 0.525; RR = 1.51, 95% CI: 0.24-9.31, p = 0.659), or MACE (I2 = 0.0%, p = 0.887; RR = 2.47, 95% CI: 0.55-11.05, p = 0.236). Intracoronary MSC administration after STEMI is associated with a modest improvement in left ventricular function, while no reduction in clinical events was found. No major safety signal was identified, although available safety data remain limited. Larger and well-designed trials with longer follow-up are still needed. Trial Registration: PROSPERO: CRD420261286620.
Clinical relevance
Despite optimized reperfusion strategies for STEMI, a significant subset of patients sustains irreversible myocardial injury and progresses to adverse ventricular remodeling and heart failure, representing an unmet therapeutic need. This meta-analysis synthesizes the highest level of available evidence—RCTs—on intracoronary MSC therapy, a biologically plausible regenerative approach targeting post-infarction myocardial repair. Cardiologists managing post-STEMI patients must critically appraise the functional versus clinical event data before considering or recommending cell-based therapies.
Key findings
1. Intracoronary MSC administration produced a statistically significant improvement in delta LVEF (ΔLVEF) compared to standard care (WMD = 3.18%, 95% CI: 1.52–4.83, p < 0.001), with low-to-moderate heterogeneity (I² = 44.6%, p = 0.108). 2. No significant reduction in rehospitalization for heart failure was observed (RR = 1.14, 95% CI: 0.36–3.61, p = 0.831), with no heterogeneity across trials (I² = 0.0%, p = 0.592). 3. All-cause mortality did not differ significantly between MSC and control groups (RR = 1.51, 95% CI: 0.24–9.31, p = 0.659; I² = 0.0%, p = 0.525). 4. Major adverse cardiovascular events (MACE) were not significantly reduced with MSC therapy (RR = 2.47, 95% CI: 0.55–11.05, p = 0.236; I² = 0.0%, p = 0.887). 5. The quantitative analysis included 7 RCTs (400 patients) after exclusion of one trial flagged with an Expression of Concern, out of 8 RCTs (796 patients) identified in the systematic review. 6. No major safety signal attributable to intracoronary MSC administration was identified, though the authors note that available safety data remain limited in scope and follow-up duration.
Practice implications
Intracoronary MSC therapy should not yet be adopted into routine post-STEMI care, as the observed ~3% absolute improvement in LVEF has not translated into reductions in hard clinical endpoints—heart failure hospitalization, MACE, or all-cause mortality—in the available RCT evidence. Clinicians considering MSC therapy should restrict its use to the context of well-designed clinical trials with pre-specified patient selection criteria (e.g., reperfused STEMI with reduced LVEF), standardized cell dosing and delivery protocols, and sufficiently long follow-up to capture meaningful clinical outcomes. Larger, adequately powered multicenter RCTs with rigorous safety monitoring and extended follow-up are required before any evidence-based recommendation for clinical adoption can be made.