Context: Numerous randomized controlled studies assessing intracoronary bone marrow cell therapy (BMC) after acute myocardial infarction (AMI) have been performed.
Objective: To systematically review the effect of autologous BMC therapy on left ventricular function by performing an up to date meta-analysis of randomized controlled trials (RCTs) including long-term follow-up.
Data sources: Trials were indentified through a literature search from 1980 to June 2012 of the Pubmed, Embase, Cochrane database, and the Current Controlled Trials Register.
Study selection: Randomized clinical trials comparing intracoronary BMC infusion to control as treatment for AMI.
Data extraction: The primary endpoint was the change in left ventricular ejection fraction (LVEF) from baseline to follow-up. Secondary endpoints were changes in left ventricular end diastolic volume (LVEDV), left ventricular end systolic volume (LVESV), infarct size and clinical outcomes.
Results: Improvement of LVEF in patients receiving intracoronary BMC was significantly better within 6 months (23 studies, 2.23% (95% confidence interval (CI) 1.00 to 3.47); p<0.001). At 12 months of follow-up, this effect sustained with 3.91% more LVEF improvement (11 studies, (95% CI 2.56 to 5.27), p<0.001). At long-term follow-up, we found a trend for better LVEF improvement in favor of cell therapy (7 studies, 1.90% (95% CI -0.43 to 4.23); p=0.11). There was no clear effect in infarct size or LVEDV. However, we found a significant reduction in LVESV at 6 months (-4.81 ml (95% CI -7.86 to -1.76); p<0.001 and at 12 months (-9.41 ml (95% CI -13.64 to -5.17); p<0.001). Moreover, there was a statistically significant decrease in recurrent AMI (Relative Risk (RR) 0.44 (95% CI 0.24 to 0.79); p=0.007), and readmission for heart failure, unstable angina or chest pain (RR 0.59 (95% CI 0.35 to 0.98); p=0.04) in favour of cell therapy.
Conclusion: Intracoronary BMC treatment leads to a moderate improvement of LVEF and reduction of LVESV at 6 months that sustained at 12 months follow-up, without a clear significant effect on LVEDV, or infarct size. Furthermore, we found that intracoronary cell therapy is significantly associated with a reduction in recurrent AMI and readmission for heart failure, unstable angina or chest pain.