Abstract 3688: Predictors of Contractile Recovery of Left Ventricular Function After Intracoronary Infusion of Bone-Marrow-Derived Progenitor Cells in Patients with Acute Myocardial Infarction: Lessons from the REPAIR-AMI Trial
Background: The REPAIR-AMI trial has demonstrated that intracoronary infusion of bone marrow-derived progenitor cells (BMC) is associated with a larger recovery of left ventricular contractile function after acute myocardial infarction (AMI) compared to placebo. The present exploratory analysis aims to identify clinical and baseline LV functional predictors of the therapeutic benefit of intracoronary BMC infusion.
Methods: Using a double-blind, placebo controlled multicenter trial design, we randomized 204 patients with successfully reperfused acute myocardial infarction to receive intracoronary infusion of bone marrow - derived progenitor cells (BMC, n = 101) or placebo medium (n= 103) into the reperfused infarct artery. Primary end point was improvement of LV ejection fraction after 4 months.
Results: Overall, recovery of global left ventricular ejection fraction was significantly (p = 0.014) greater in the bone marrow-derived progenitor cell infusion group compared to placebo (absolute difference 5.5 ± 7.3 % versus 3.0 ± 6.5 %; treatment effect = 2.5 Δ% 95%CI 0.51 - 4.5). BMC-associated treatment effect was most pronounced in patients with the most severely depressed left ventricular function at baseline (< median EF of 48.9%: treatment effect = 5.0 Δ% 95%CI 2.0 - 8.1) and later timing of the procedure (≥day 5 after reperfusion therapy: treatment effect = 5.1 Δ% 95%CI 1.7 - 8.5). Efficacy of intracoronary BMC infusion was independent of the presence of diabetes (p for interaction = 0.57), use of aldosterone antagonists (p =0.83), and the occurrence of clinical events during follow up (myocardial infarction or revascularizations, p = 0.91).
Conclusions: Intracoronary infusion of bone marrow-derived progenitor cells is associated with enhanced efficacy in patients with the most severe depression of left ventricular function as well as when performed at ≥ 5 days after AMI reperfusion therapy. These findings of the REPAIR-AMI trial may provide important information to design future trials to assess the effect of intracoronary BMC administration on clinical outcome.