Autologous Bone Marrow Stem Cell Therapy in Patients With ST-Elevation Myocardial Infarction: A Systematic Review and Meta-analysis

Background: Randomized controlled trials (RCTs) on bone marrow stem cell (BMSC) therapy in ST-elevation myocardial infarction (STEMI) patients have reported conflicting results. Our main objective was to critically appraise and meta-analyze best-available evidence on efficacy and safety of intracoronary administration of autologous BMSC therapy in STEMI patients after primary percutaneous coronary intervention. Methods: We conducted a search of MEDLINE, PubMed, EMBASE, CENTRAL, Global Health, CINAHL, and conference proceedings in February 2017. Our primary outcome was all-cause mortality. Secondary and safety outcomes included cardiac death, heart failure, arrhythmias, repeat myocardial infarction, or target vessel revascularizations; or improved health-related quality of life, left ventricular ejection fraction, or infarct size. Summary relative and absolute risks were obtained using random effects models. We also evaluated the strength of evidence. Results: A comprehensive database search identified 42 RCTs (3365 STEMI patients). BMSC therapy did not significantly decrease mortality (risk ratio, 0.71; 95% confidence interval, 0.45-1.11; I-2, 0%; absolute risk reduction, 0.1%; 95% confidence interval, -0.71 to 0.91; 40 trials; 3289 participants; I-2, 0%; low strength of evidence). BMSC therapy had no effect on secondary or adverse outcomes. Trial sequential analysis for all-cause mortality showed no evidence of a clinically important difference, with a very low probability that future studies can change the current conclusion. Conclusions: On the basis of evidence from 42 RCTs published in the past 15 years, we provide conclusive evidence for a lack of beneficial effect for autologous BMSC therapy in patients with STEMI.