Age, gender and diabetic status are associated with effects of bone marrow cell therapy on recovery of left ventricular function after acute myocardial infarction: a systematic review and meta-analysis.

Clinical studies on intracoronary bone marrow cell (BMCs) infusion in patients with acute myocardial infarction (AMI) revealed mixed results. Recently, meta-analysis on this topic have been conducted and found that there was marked heterogeneity between trials. The objective of this systematic review is to have a retrospection of the efficacy of cell therapy and explore whether the study design or characteristics of subjects may have influenced the effects of cell therapy on recovery of left ventricular function after AMI. Trials were identified in ClinicalTrial, mRCT, Cochrane Library, EMBASE, and PubMed databases, reviews, and reference lists of relevant papers. The weighted mean difference (WMD) was calculated for net changes in left ventricular ejection fraction (LVEF) by using random-effect models. Meta-regression analyses were performed to explore the influence of study characteristics. Ten randomized controlled trials (12 comparisons) with a total of 814 participants were included. In an overall pooled estimate, compared with the control group, BMCs therapy significantly improved the LVEF change from baseline to follow-up (WMD: 3.79%, 95% CI: 2.4-5.7%, P<0.001; heterogeneity test: I(2)=82.7%, P<0.001). A multivariate meta-regression analysis was conducted to investigate the potential sources of heterogeneity. The model including age (coefficient=21%, P=0.04), male proportion (coefficient=-14%, P=0.001) and diabetic patients' proportion (coefficient=17%, P=0.002) explained most of the identified heterogeneity. The present systematic review and meta-analysis suggest that (1) BMCs therapy is effective at improving the LVEF; (2) BMCs therapy is more effective in ageing and diabetic individuals, whereas less effective in males.