Abstract 3770: Left Ventricular Function after Intracoronary Infusion of Bone Marrow-Derived Progenitor Cells after Acute STEMI: MRI Substudy of the Double-blind, Randomized, Placebo-controlled Multicenter REPAIR-AMI Trial
Background: The REPAIR-AMI trial has shown a beneficial effect of intracoronary infusion of bone-marrow-derived progenitor cells (BMC) on left ventricular function, assessed by quantitative left ventricular angiography. Especially patients with large infarcts (below the median ejection fraction) derived the most benefit from therapy. The goal of the present substudy is to scrutinize these findings by MRI as the gold standard technique to assess myocardial function and volumes.
Methods: In this double-blind, randomized, placebo-controlled multicenter trial, pts with successful reperfusion therapy of a STEMI were randomized into intracoronary infusion of bone marrow-derived progenitor cells or placebo medium. Sixty of the randomized 204 patients participated in the MRI substudy (n = 30 BMC, n = 30 Placebo). Left ventricular function and dimensions were quantitated using SSFP-cine sequences and multi-slice short axis volumetry at the index hospitalization and after 4 months.
Results: Baseline ejection fraction (EF) was similar in the BMC and Placebo group in patients with an EF below the median of 48.9% (BMC = 38.7 ± 8.1%, Placebo = 40.5 ± 8.0%, p = 0.54) and those above the median (BMC = 56.5 ± 4.1%, Placebo = 55.1 ± 6.2 %, p = 0.45). In patients with baseline EF below the median, ejection fraction increased by 5.0 ± 5.7% (p = 0.014), whereas there was no change in ejection fraction in the placebo group (−0.82 ± 7.8 %, p = 0.68). Thus, BMC treatment effect on EF was 5.8 absolute % increase in EF
(p = 0.034). In contrast, patients with smaller infarcts (≥ median of baseline EF), derived no benefit from the therapy (treatment effect −0.9 %). In patients with baseline EF < median, BMC therapy was associated with a significant decline of enddiastolic volumes (treatment effect -29 ml, 95%CI -0.7 to -58 ml, p = 0.045) and endsystolic volumes (treatment effect -28 ml, 95%CI -2.1 to −53 ml, p = 0.035).
Conclusions: In patients with a large ST elevation myocardial infarction, intracoronary infusion of BMC significantly enhances recovery of left ventricular contractile function and beneficially interferes with left ventricular remodeling processes in the 4 months follow-up. Therefore, MRI findings confirm that BMC therapy holds great promise to limit post infarction heart failure.