LAUSR

Background and purpose: Cardiac involvement leading to progressive heart failure is a major cause of death in Duchenne and Becker muscular dystrophy (DMD/BMD) patients. T1 mapping and extracellular volume fraction (ECV) calculation are unique techniques for assessing the very early phases of cardiac involvement. The aim of the study was to compare native T1 and ECV measurements between visually non-fibrotic myocardium of DMD/BMD patients and controls. Methods: In total, 50 male individuals – 39 DMD/BMD patients (14±5 years) and 11 matched controls (17±3 years, p = NS) without history predisposing to cardiac dysfunction or fibrosis, but with a clinical indication for cardiovascular magnetic resonance (CMR) evaluation underwent CMR examination. Native and post contrast T1 mapping using Modified Look-Locker Inversion-recovery (MOLLI) sequence was included. Data points collected include left ventricular (LV) ejection fraction (EF), indexed end-diastolic LV volume (iEDV), indexed left ventricular mass, mitral annular plane systolic excursion (MAPSE), presence of late gadolinium enhancement (LGE), native T1, and ECV. Results: DMD/BMD subjects had LVEF of 59±13%, iEDV 56±22, iSV 31±8, MAPSE 11±1; 15/35 (43%) had LGE, all confined to the lateral wall. Five (13%) of them had LVEF <50%. Controls had LVEF 65±8% (p = NS), iEDV 59±9 (p = NS), iSV 38±8 (p<0.05), MAPSE 14±3 (p<0.05) and no LGE (p<0.05). While native T1 values were significantly higher in the DMD/BMD group compared to controls - 1028±44 versus 985±10 (p<0.05), ECV didn't differ statistically between groups – 0,24±0,03 versus 0,23±0,01 (p = NS). Conclusion: DMD/BMD patients had worse longitudinal and global LV systolic function, and had higher incidence of regional myocardial fibrosis. Native T1 values of LGE-free myocardium were significantly higher in muscular dystrophy patients. Acknowledgement/Funding: LQ1605 from the National Program of Sustainability II (MEYS CR)