Effects of cardiac medications on ventricular function in patients with Duchenne muscular dystrophy-related cardiomyopathy.

INTRODUCTION/AIMS: The DMD Care Considerations Working Group Guidelines 2010 recommended treating cardiac dystrophinopathy with angiotensin-converting enzyme-inhibitor (ACEi) and beta-blocker (BB) therapy to prevent the progressive decline in left ventricular function expected from earlier, natural history studies. The aim of this research was to audit change in measures of left ventricular function over 8 years to 4 years before and 4 years after deploying an ACEi/BB combination systematically at a dedicated "cardiology-muscle" clinic.

METHODS

This is an institutionally registered, retrospective, case-file-based audit of serial echocardiographic measures of left ventricular fractional shortening accumulated over the period 1995 to 2015.

RESULTS

Data from 104 genetically confirmed Duchenne muscular dystrophy (DMD) patients, aged 22.2 ± 5.3 years at data censure, were included. Mean age at first detection of left ventricular dysfunction was 15.1 ± 4.2 years, but older in those on maintenance steroid therapy (16.8 ± 4.2 vs 14.5 ± 4.1 years; P = .04). Group mean fractional shortening fell by 1.5%/year over the 4 years before therapy, but this decreased to 0.9%/year over the first 4 years after starting therapy. Analysis of limited left ventricular ejection fraction measures showed similar but nonsignificant changes. Neither age at detection of left ventricular dysfunction nor fractional shortening percent at time of therapy initiation affected the beneficial response.

DISCUSSION

The results support the international DMD recommendations of the time. This combination of cardiac medications helps stabilize heart function. For the best long-term effects, therapy needs to be initiated no later than on first detection left ventricular impairment.