Novel Cardiac Imaging Risk Score for Mortality Prediction in Duchenne Muscular Dystrophy

Abstract

Cardiovascular disease is the leading cause of death in patients with Duchenne Muscular Dystrophy (DMD), but there is significant cardiomyopathy phenotypic variability. Some patients demonstrate rapidly progressive disease and die at a young age while others survive into the fourth decade. Criteria to identify DMD subjects at greatest risk for early mortality could allow for increased monitoring and more intensive therapy. A risk score was created describing the onset and progression of left ventricular dysfunction and late gadolinium enhancement in subjects with DMD. DMD subjects prospectively enrolled in ongoing observational studies (which included cardiac magnetic resonance [CMR]) were used to validate the risk score. A total of 69 subjects had calculable scores. During the study period, 12 (17%) died from complications of DMD. The median risk score was 3 (IQR [2,5]; range [0,9]). The overall risk score applied at the most recent imaging age was associated with mortality at a median age of 17 years (IQR [16,20]) (HR 2.028, p < 0.001). There were no deaths in subjects with a score of less than two. Scores were stable over time. An imaging-based risk score allows risk stratification of subjects with DMD. This can be quickly calculated during a clinic visit to identify subjects at greatest risk of early death.