Intracoronary Infusion of Bone Marrow-Derived Mononuclear Cells Abrogates Adverse Left Ventricular Remodelling Post-Acute Myocardial Infarction: Insights from the Reinfusion of Enriched Progenitor Cells and Infarct Remodelling in Acute Myocardial Infarction (REPAIR-AMI) Trial

AIMS: Depressed left ventricular ejection fraction (LVEF) despite successful reperfusion therapy is the single most powerful predictor of progressive LV enlargement after acute myocardial infarction (AMI) and independently determines adverse outcome in these patients. METHODS AND RESULTS: We investigated the effect of intracoronary administration of bone marrow-derived mononuclear cells (BMC) within 7 days after successful reperfusion therapy for AMI, on early (within 4 months) LV remodelling processes assessed by quantitative LV angiography. Overall, 95 patients received BMC and 92 patients received placebo. Remodelling was assessed as the changes in either LVEF and end-systolic volume (ESV) or stroke volume and end-diastolic volume (EDV) at 4 months, respectively. Baseline LVEF was inversely correlated with ESV expansion at 4 months in the placebo group, but not in the BMC group. Likewise, EDV expansion was significantly correlated with baseline LVEF in the placebo (r = -0.36, P < 0.001), but not in the BMC group (r = -0.17, P = 1.0). Analysing the interaction between convalescent LV contractile function and LV volumes revealed that the increase in LVEF or stroke volume did not occur at the expense of increases in ESV or EDV, respectively, in the BMC group. CONCLUSION: Intracoronary administration of BMC eliminates the correlation between depressed LVEF after reperfusion therapy and LV expansion during follow-up and, thereby, abrogates early LV remodelling after AMI.