Randomized controlled trials on the therapeutic effects of adult progenitor cells for myocardial infarction: meta-analysis.

OBJECTIVE We performed a systematic meta-analysis to assess the therapeutic effects of progenitor cell therapy after myocardial infarction (MI). RESEARCH DESIGN/METHODS Randomized controlled trials of progenitor cell therapy for MI were extracted from MEDLINE. We performed a prospective comparison of progenitor cell therapy versus placebo after acute or chronic MI, with changes in left ventricular ejection fraction (LVEF) as the primary endpoint. We conducted random-effects meta-analyses to pool these outcomes across the studies. RESULTS A total of 980 patients from 18 studies were analysed. Seventeen trials used bone marrow-derived cells (BMCs). Overall, BMCs significantly increased LVEF, left ventricular end systolic volume and left ventricular end diastolic volume within six months of treatment, and the effect was sustained one year later. Following BMC transplantation regional myocardial anatomy displayed statistically and clinically significant improvements compared with controls, albeit without functional changes. Similar results were observed in the subgroup of patients with impaired LVEF at the baseline. The subgroup analysis suggested a benefit of BMCs on LVEF in acute but not chronic MI. LVEF enhancement seemed to correlate positively with dose and inversely with the storage duration of the BMCs. CONCLUSIONS BMC transplantation for MI was able to deliver benefits over regular therapy even at an 18-month follow-up, particularly when used to treat acute MI. CD34(+) cell therapy holds promise for MI treatment in the future.