Short- and long-term outcomes of intracoronary and endogenously mobilized bone marrow stem cells in the treatment of ST-segment elevation myocardial infarction: a meta-analysis of randomized control trials

Aims Bone marrow stem cell (BMSC) treatment of ST-segment elevation myocardial infarction (STEMI) has been primarily via the intracoronary route or via endogenous mobilization using granulocyte colony-stimulating factor (G-CSF). Studies have provided conflicting results. We therefore performed a meta-analysis of these treatments, examining short-and long-term efficacy and safety. Methods and results Randomized controlled trials (RCTs) of BMSC-based therapy for STEMI, delivered within 9 days of reperfusion, were identified by systematic search. Random effects models were used to calculate pooled effects of clinical outcomes, with meta-regression to assess dependence of the magnitude of effect sizes on study characteristics. Twenty-nine RCTs enrolling 1830 patients were included. Intracoronary BMSC therapy resulted in an overall improvement in left ventricular ejection fraction (LVEF) of 2.70% [95% confidence interval (CI) 1.48-3.92; P < 0.001] in the short term and 3.31% (95% CI 1.87-4.75; P < 0.001) longer term. Meta-regression suggested a dose-response relationship between quantity of CD34(+) cells delivered and increase in LVEF (P = 0.007). G-CSF treatment resulted in a trend towards similar benefits (P = 0.20). No significant differences were observed in pooled adverse outcome rates between intervention and control groups of either treatment approach, except for lower revascularization rates with intracoronary BMSC vs. control (odds ratio 0.68, 95% CI 0.47-0.97; P = 0.03). Conclusions Intracoronary BMSC therapy post-STEMI improves LVEF beyond standard medical treatment, in both the short and longer term. G-CSF treatment shows positive but non-significant trends. Both treatments demonstrate safety comparable with conventional medical treatment.