Effects of intracoronary autologous bone marrow cells on left ventricular function in acute myocardial infarction: a systematic review and meta-analysis for randomized controlled trials

Background Experimental and clinical studies have suggested that intracoronary infusion of bone marrow-derived stem/progenitor cells (BMC) may improve left ventricular function after acute myocardial infarction (AMI). We conducted a systematic review and meta-analysis to investigate the efficacy and safety of BMC therapy on global left ventricular function in AMI. Methods A systematic literature search of MEDLINE, Cochrane Controlled Trials Register, EMBASE, Science Citation Index, and PUBMED from their inception to March 2007 was conducted using specific search terms. Reference lists of papers and reviews on the topic were further searched. Finally, six randomized controlled trials that comprised 517 patients were eligible for further meta-analysis. We used a standardized protocol to extract information on the included studies. Results Compared with the control groups, BMC therapy produced a slight improvement of the follow-up left ventricular ejection fraction (LVEF) [2.53%, 95% confidence interval (CO: 0.67-4.39, P= 0.0081 between 3 and 6 months. Similarly, BMC therapy also significantly improved the LVEF change from baseline to follow-up [2.88%, 95%CI: 1.69-4.08, P=0.0001 compared to control groups, and the heterogeneity across the studies with regards to the follow-up LVEF (P=0.696) and the LVEF change (P=0.1 79). Major adverse cardiovascular events, including ventricular arrhythmia, rehospitalization for heart failure, and the composite of other cardiovascular events (cardiac death, recurrent myocardial infarction, infarct-vessel revascularization procedure, and stroke), were not significantly different between BMC therapy and control groups [relative risk (RR): 1.19, 95%CI: 0.68-2.06; RR: 1.79, 95%CI: 0.62-5.17; and RR: 1.05, 95%CI: 0.81-1.35, respectively]. Conclusion On the basis of present evidence, intracoronary BMC infusion in patients with AMI seems to be safe and associated with slight improvement of the left ventricular ejection fraction at 3-6 months' follow-up.