Journal of Stem Cell Research & Therapy

Abstract

Are Selected Bone Marrow Stem Cells More Effective than Unselected Ones in Patients with Chronic Myocardial Infarction?

Hyunsuk Jeong, Hyeon Woo Yim, Hun-Jun Park, Sona Jeong and Hyun-bin Kim

Introduction: The aim of the study was to examine the effectiveness of selected bone marrow-derived stem cell (BMSC) on improving Left Ventricular Ejection Fraction (LVEF) from Randomized Controlled Trials (RCTs) to treat patients with Chronic Myocardial Infarction (CMI). Methods: We searched Medline from 1946 to March 2012 for studies of BMSC transplantation in patients with CMI. The included studies met the following criteria: RCTs, CMI patients who received Coronary Artery Bypass Graft (CABG), BMSC were infused intramuscularly, cell injection in peri-infarct zone, and studies that had up to 6 month follow-up. Results: The initial search identified 8,433 references, of which 7 RCTs met the inclusion criteria. Selected bone marrow stem cells were injected in three of the 7 trials while unselected BMSC was injected to the treatment group in the rest 4 trials. The treatment effects of the studies in which the treatment group was injected with CD34+ and CD133+ were greater than the studies that used unselected BMSC (7.66%, 95% CI: 4.16-11.15 vs. 4.77%; 95% CI: 2.08-7.46). Planned sub-group analyses revealed that the treatment effects on improvement in LVEF differed according to the measurement tools used on outcome assessment, treatment blindness, and methods of surgery. Conclusion: Selected BMSC appeared to show more effective than unselected BMSC. However, the intervention effect of selected BMSC might be overestimated because the studies tended to use less rigorous designs, less precise outcome measures, and different methods of surgery than those using unselected BMSC. Therefore these treatment effects of selected BMSC should be interpreted cautiously.