Left Ventricular End-Diastolic Diameter and Cardiac Mortality in Duchenne Muscular Dystrophy

PURPOSE: This study aimed to examine weather left ventricular end-diastolic diameter (LVDd) could predict mortality from heart failure in patients with Duchenne muscular dystrophy (DMD) receiving standard cardio-protective therapies. PATIENTS AND METHODS: One hundred thirty-three patients with DMD aged ≥10 years who underwent echocardiography from 2011 to 2015 were included in this study and retrospectively followed until August 2018. Patients were divided into two groups according to LVDd at initial echocardiography: ≤ 54 mm (Group 1: n=119) and ≥ 55 mm (Group 2: n=14). To identify factors other than LVDd that may affect heart failure-related mortality, Group 2 patients who developed no left atrial (LA) enlargement, moderate mitral regurgitation (MR), or pulmonary hypertension (PH) during the observation period (Group 2A: n=5) were compared with those who newly developed one or more of those complications (Group 2B: n=7). Clinical outcomes were all-cause mortality and mortality from heart failure. RESULTS: Mean observation period was 5.5±1.5 years in Group 1 and 4.4±1.9 years in Group 2. A total of 14 patients (10.5%) died, including 6 of 119 (5.0%) patients in Group 1 and 8 of 14 (57.1%) patients in Group 2 (p<0.001). Among these, 1 (0.8%) patient in Group 1 and 8 (57.1%) patients in Group 2 died from heart failure (p<0.001). Group 2B patients had shorter survival compared to Group 2A patients (p=0.006). CONCLUSION: LVDd ≥ 55 mm is a predictive factor for mortality from heart failure in patients with DMD. Complications including LA enlargement, moderate MR, and PH were found to be predictive factors for mortality from heart failure in a short period.