Abstract 12730: Cardiosphere-derived Cells Improve Segmental Myocardial Circumferential Strain by Magnetic Resonance Imaging: Results From the Allogeneic Heart Stem Cells to Achieve Myocardial Regeneration Study

Abstract

Introduction: Cell therapy failed to improve global LV ejection fraction (LVEF) in most trials of post-MI LV dysfunction. LVEF does not consider the effect of cell therapy on different segments of the myocardium, which may be heterogeneous across different myocardial regions in patients with regional MI. Hypothesis: Allogeneic cardiosphere-derived cells (CDCs) improve segmental (but not global) myocardial function indexed as circumferential strain by MRI. Methods: In this randomized double-blind trial, 142 post-MI patients with LVEF<45% and 15% or greater LV scar size were randomized in 2:1 ratio to receive intracoronary infusion of allogenic CDCs or placebo, respectively. Change in segmental myocardial circumferential strain (Ecc) by MRI from baseline to 6-month was compared between CDCs and placebo groups. Results: In total, 124 patients completed the 6-month follow-up (mean (SD) age 54.3(10.8) and 108 (87.1%) males). Segmental Ecc improvement was significantly greater in patients receiving CDC (-0.5%(4.0)) compared to placebo (0.2%(3.7), p=0.05). The greatest benefit for improvement in segmental Ecc was observed in segments containing scar tissue (change in segmental Ecc of -0.7% (3.5) in patients receiving CDC vs. 0.04% (3.7) in the placebo group, p=0.04). The beneficial effect of CDCs for improving segmental Ecc was greater in patients with LV ejection fraction<41%, LV scar size>18.8% or LV end-diastolic volume index>100 [mixed effect regression coefficients of -0.92(p=0.02),-0.78(p=0.03), and -1.16(p=0.004) respectively versus -0.58(p=0.05) for the entire cohort]. Conclusions: In patients with post-MI LV dysfunction, allogeneic CDC administration resulted in improved segmental myocardial function. This CDC induced improvement in segmental myocardial function was greater in patients with severe LV dysfunction, dilated LV and greater infarct size. (clinicaltrials.gov Identifier: NCT01458405).