Background: Despite rapid clinical translation and widespread enthusiasm, the therapeutic benefits of adult bone marrow cell (BMC) transplantation in patients with ischemic heart disease (IHD) continue to remain controversial. A synthesis of the available data is critical to appreciate and underscore the true impact of this promising approach.
Methods and Results: A total of 50 studies (enrolling 2,625 patients) identified by database searches through January 2012 were included. Weighted Mean Differences for changes in left ventricular (LV) ejection fraction (LVEF), infarct size, LV end-systolic volume (LVESV), and LV end-diastolic volume (LVEDV) were estimated using random effects meta-analysis. Compared with controls, BMC-treated patients exhibited greater LVEF (3.96%, 95% confidence interval (CI): 2.90, 5.02; P<0.00001), and smaller infarct size (-4.03%, CI: -5.47, -2.59; P<0.00001), LVESV (-8.91 ml, CI: -11.57, -6.25; P<0.00001), and LVEDV (-5.23 ml, CI: -7.60, -2.86; P<0.0001). These benefits were noted irrespective of the study design (RCT vs. Cohort study) and the type of IHD (acute myocardial infarction vs. chronic IHD), and persisted during long-term follow-up. Importantly, the all-cause mortality, cardiac mortality, and the incidence of recurrent MI and stent thrombosis were significantly lower in BMC-treated patients compared with controls. Conclusions: Transplantation of adult BMCs improves LV function, infarct size, and remodeling in patients with IHD compared with standard therapy, and these benefits persist during long-term follow-up. BMC transplantation also reduces the incidence of death, recurrent MI, and stent thrombosis in patients with IHD.