Effects of angiotensin-converting enzyme inhibitors and/or beta blockers on the cardiomyopathy in Duchenne muscular dystrophy

Abstract

Cardiomyopathy is a consequence of Duchenne muscular dystrophy (DMD). Suggested treatments include angiotensin-converting enzyme (ACE) inhibitors and/or β blockers (BBs), but few large series have been reported. We present 42 patients with DMD and cardiomyopathy treated with an ACE inhibitor or an ACE inhibitor plus a BB. Serial echocardiograms were recorded. Adequate ejection fractions (EFs) were obtained at initiation of therapy (EF <55%). ACE inhibitor dosage adjustments were made if a continued decrease in EF was noted. BB therapy was initiated when average heart rate on Holter monitoring exceeded 100 beats/min. Data were analyzed using paired t test and linear regression. Before ACE inhibition, patients (n = 22) demonstrated decreased EF over time (r(2) = 0.23). At ACE inhibitor therapy initiation, mean age was 14.1 ± 4.6 years and mean EF was 44.2 ± 6.8%. BB therapy was used in 24 of 42 patients. Mean age for the ACE inhibitor + BB group was 15.7 ± 3.9 years. The 2 groups showed significant improvement (p <0.0001 for ACE inhibitor and ACE inhibitor plus BB) compared to the pretherapy group. No significant differences were noted between treatment groups. Patients with DMD demonstrated a gradual decrease in myocardial function. Treatment with ACE inhibitor or ACE inhibitor plus BB resulted in significant improvement compared to pretherapy. No significant difference occurred in EF improvement between treatment groups. In conclusion, treatment with ACE inhibitor or ACE inhibitor plus BB can delay progression of cardiomyopathy.