A systematic review of pharmacologic therapies for the cardiomyopathy of Duchenne muscular dystrophy

Objective To perform a systematic review of studies evaluating pharmacologic therapies for the cardiomyopathy of Duchenne muscular dystrophy (DMD). Methods: PubMed, Google Scholar, and Embase were searched through October 8, 2020. Articles were selected using pre-determined criteria; 26 underwent detailed review by two co-authors. Study quality was assessed with the Newcastle-Ottawa scoring system (NOS); GRADE assessment evaluated their overall clinical importance. Results There were few randomized controlled trials. Two of four trials of angiotensin converting enzyme inhibitors (ACEI) or ACEI plus beta-blockers (BB) found improved LV function. Two of two randomized trials of aldosterone antagonists (AA), when added to ACEI and BB therapy, demonstrated less decline of LV circumferential strain over 1 year of treatment. Observational studies of ACEI and BB had differing patient ages, symptomatology, cohort size, study duration and baseline heart function. LV function, assessed via unblinded imaging, was the most frequent outcome measure. LV dysfunction improved in some trials but was unconfirmed in others. Class IV heart failure patients had transient improvement of symptoms and LVEF. Most NOS scores reflected a low level of study quality. The Grade certainty rating, used for the summation of studies, was between "low" and "moderate." Conclusion Randomized trial evidence was inconsistent that either ACEI or BB or their combination improve LV function and/or alter progressive LV dysfunction. When ACEI and BB therapy are initiated for symptomatic Class IV heart failure, symptoms and LVEF improve transiently. AAs retard the rate of decline of LV function when initiated in younger DMD patients.