Abstract 10863: Left Ventricular Apical Injury Augments Stroke Likelihood in Patients With Systolic Dysfunction and No Left Ventricular Thrombus - Multiparametric Tissue Characterization and Strain Assessment via Cardiac Magnetic Resonance

Abstract

Introduction: Patients (pts) with left ventricular (LV) dysfunction are at increased stroke risk even in absence of LV thrombus (LVT), but conventional indices such as ejection fraction (LVEF) have limited predictive value. Cardiac MRI (CMR) enables precise assessment of LV function and infarction, providing utility to test novel markers for stroke risk. Methods The population comprised pts with LVEF <50% and no LVT on CMR. Stroke was determined by blinded chart review. LV infarction, LVEF, LV and LA geometry, and segmental wall motion were measured on CMR. To further test association of LV contractility with events, radial strain was quantified in LVEF matched (1:1) pts with and without CVA; segmental data were regionally partitioned (base, mid, apex). Results 556 pts were studied; 7% (n=40) had stroke. Pts with stroke were older (68±14 vs 60±15 yo) and more likely to have AF (33 vs 18%) or CAD (55 vs 35%; all p<0.05) but did not differ based on CV risk factors (p=NS). Despite similar LVEF (37±8 vs 38±9%) and LV, LA size (p=NS), stroke pts had higher apical wall motion score (8.5±4.4 vs 6.6±3.6) and infarct size (5.3±6 vs 2.4±4.4%; each p<0.01) - each associated with stroke (p<0.001) independent of infarct or dysfunction in non-apical regions. Both apical wall motion (B=1.12 [1.02-1.22]; p=0.013) and infarct (B=1.10 [1.03-1.17]; p=0.006) associated with stroke controlling for age, clinical AF and CAD ( Table ). Among LVEF matched pts, radial strain tended to be higher in the basal LV (192.0±77.7 vs 165.5±56.1; p=0.09) and equivalent in the mid LV (177.8±63.3 vs 175.1±67.2; p=0.85), but apical radial strain was 30% lower (79.2±42.8 vs 109.1±62.4; p=0.015) in pts with, vs. those without stroke. Conclusion Among pts with LV dysfunction and no LVT, apical injury augments likelihood of stroke. Parallel associations of LV apical strain quantification, wall motion, and infarction with events support apical injury as risk factor for embolic events even in absence of LVT at time of imaging.