The Role of Prophylactic Heart Failure Therapy in Duchenne Muscular Dystrophy

Purpose There is variable practice and debate surrounding prophylactic heart failure (HF) therapy in Duchenne Muscular Dystrophy (DMD) patients with normal systolic function. We sought to determine the impact of HF medications including ACE inhibitors and ARB on the development of moderate systolic dysfunction or death in a cohort of DMD patients. Methods We performed a retrospective cohort study of DMD patients followed at 17 centers across North America from 1/1/2005-12/31/2015. Inclusion criteria were normal systolic function on baseline echocardiogram (ejection fraction (EF) ≥ 55%) and age ≥ 9 years during the study. Moderate systolic dysfunction was defined as an EF≤40% or shortening fraction ≤21% if EF was not available. We compared the composite outcome of moderate systolic dysfunction or death in patients who started HF therapies before evidence of systolic dysfunction (PPX) vs those who did not (non-PPX) using a Cox proportional hazards regression model adjusting for baseline age. We also compared prophylaxis with ACE/ARB (ACE/ARB PPX) to non-PPX. Results 277 males with DMD and normal systolic function were included. Prophylactic HF medications were used in 70 patients (25%) which included ACE/ARB (44, 63%), beta blocker (26, 37%), aldosterone blockade (6, 9%) and digoxin (5, 7%). Medications began at a mean (SD) age of 13.6 (4) years. Mean baseline ages were 10.7 (4.2) and 9.9 (3.9) years in the PPX and non-PPX groups (p=0.16), while mean age to develop moderate systolic dysfunction was 18.6 (5.4) and 16.8 (4.0) in the PPX and non-PPX groups (p=.005). The risk of developing moderate systolic dysfunction or death was 50% lower in the PPX group compared to the non-PPX group (HR=0.50; p=.044) and 79% lower in the ACE/ARB PPX group (N=38) compared to the non-PPX group (HR=0.21; p=0.035) (Figure 1). Conclusion There is variability in the use and choice of prophylactic HF medications in boys with DMD. This cohort showed a benefit to introduction of ACE/ARBs prior to evidence of systolic dysfunction.