Abstract 13519: 4D Cardiac Magnetic Resonance Strain Associates With Mortality in Duchenne Muscular Dystrophy Associated Cardiomyopathy

Abstract

Introduction: Cardiomyopathy (CM) is the leading cause of death in Duchenne muscular dystrophy (DMD) but the pace of CM progression is variable. Identification of biomarkers that associate with mortality could allow clinicians to intensify cardiac therapy. Our objective was to determine whether novel 4D (3D+time) cardiac magnetic resonance (CMR) strain analysis predicts mortality. We hypothesized that the magnitude of regional surface strain (E a ) would be significantly decreased in DMD patients that progressed to mortality within 5 years of analysis. Methods: Short axis cine CMR images for DMD survival (n=40) and non-survival (n=9) groups were compiled into 4D sequences. For all 4D sequences, epi- and endocardial borders were segmented across one cardiac cycle for kinematic analysis using a custom-built MATLAB graphical user interface (MathWorks, Natick, MA). Regional E a was measured by determining the relative change in the localized 4D endocardial surface mesh compared to end diastole. Unpaired t-test was used to determine statistical significance. Results: DMD survival patients were younger (13 years [8-24]; median [range]) than non-survival patients (16[12-19]) and a smaller portion had LVEF<55% (11 (28% of total) vs. 6 (67% of total). 63% (n=26) of the survival group had late gadolinium enhancement vs. 100% (n=9) in the non-survival group. Median time to mortality for the non-survival group was 27 months [8-58]. Peak E a was significantly worse in the non-survival group globally and in the basal, mid, and apical regions ( p <0.001 for all; Fig1C). Qualitative E a maps show dramatic differences between groups (Fig1A,B). Conclusion: Regional E a from 4D CMR in DMD was reduced in patients that progressed to mortality within 5 years compared to those that survived. Figure 1: Example colorized surface strain (E a ) from A) survival and B) non-survival patients in both polar map (left) and 3D representations (right). C) Regional E a differences between groups. * p <0.001.