Abstract 14478: Left Ventricular (LV) Determinants of Left Atrial (LA) Remodeling in Ischemic Cardiomyopathy (iCM): From the Allogeneic Heart Stem Cells to Achieve Myocardial Regeneration (ALLSTAR) Double Blind Placebo Controlled Trial

Abstract

Introduction: ALLSTAR, a trial of cardiosphere-derived cells in iCM, phenotyped the subjects by cardiac magnetic resonance (CMR) at baseline, and 6- and 12- months post-randomization. The overall CMR dataset provides an opportunity to study temporal remodeling of the LA in the context of iCM-related LV alterations. Hypothesis: We hypothesize that LA volumetric and functional remodeling in iCM are coupled to LV determinants. Methods: LA volumes (LAV; maximum and minimum) were obtained from 4- and 2-chamber cine CMR images. LA functional parameters included total, passive and active LA emptying fractions and global longitudinal strain (GLS). LV parameters included end-diastolic and end-systolic volumes (indexed to body surface area; LVEDVi and LVESVi), as well as LV ejection fraction (EF), infarct size, GLS and end-diastolic mass. Six- and 12-month differences from the baseline CMR study were calculated for LA and LV parameters. Linear regression models were used to evaluate univariate associations between LA and LV parameters (at baseline, 6-months, 12-months and their differences [Δ]), independent of treatment effect (which is the subject of ongoing analysis). Results: 101 participants had 6-month follow up CMR studies; 57 had 12-month studies. Baseline means(SD): age 53.9(10.9) years; 87(86.1%) male; LVEF 39.7%(7.0%); infarct size 22.7%(5.4%). In univariate analyses at 6 months, ΔLVEDVi and ΔLVESVi were both significantly associated with ΔLAVimax and ΔLAVimin, but not with LA functional parameters (Table). At 12 months, ΔLVEDVi remained significantly associated with ΔLAVimax, and ΔLVESVi with ΔLAVimin. No association with LA functional parameters was seen. LVEF, infarct size, GLS and end-diastolic mass were not associated with any volumetric or functional LA parameters (not shown). Conclusions: In conclusion, in this cohort of iCM, pathologic dilatation of the LV appears coupled to volumetric LA remodeling, but not other functional LA parameters.