Cardiac Medication Use in ACTION for Duchenne Muscular Dystrophy Cardiomyopathy

This study seeks to understand cardiac medication use in a large cohort of males with Duchenne Muscular Dystrophy (DMD) followed prospectively with focus on current practices and adherence to consensus directed medical therapy (CDMT). DMD patients have been enrolled in the Advanced Cardiac Therapies Improving Outcomes Network (ACTION) Dystrophinopathy Registry since 2021. Cardiac medication use was analyzed at enrollment and most recent follow-up. CDMT was defined as concurrent use of angiotensin-converting-enzyme inhibitor (ACEi)/angiotensin II receptor blocker (ARB) /angiotensin receptor-neprilysin inhibitor (ARNI) plus beta-blocker (BB) plus mineralocorticoid receptor antagonist (MRA). Two hundred sixty-five males with DMD (median age 17.5 (IQR 14.5-21.5) years) were prospectively followed; median follow-up was 11.5 (IQR 6.2-15.6) months. At most recent follow-up, 153 patients (57.7%) had decreased LV systolic function, 67 (25.3% of the cohort) had moderate or severe dysfunction. For patients with moderate or severe dysfunction, CDMT was used for 49/67 (73.1%) at most recent follow-up, similar to 36/51 (70.6%) at enrollment (p = 0.92). Target doses of CDMT were achieved for 27% of males on ACEi/ARB/ARNI, 28% on BB, and 23% on MRA. Initial analysis of a prospective registry of males with DMD showed that ~ 30% of patients with moderate or severe LV dysfunction were not on CDMT at most recent follow-up and the majority did not reach target dosing. Further understanding regarding the optimal combination of cardiac medications for DMD cardiomyopathy is needed, as is a better understanding of the barriers to CDMT optimization given increasing cardiac causes of death for DMD patients.