Improved neuromuscular and respiratory therapies have altered the natural history of Duchenne muscular dystrophy (DMD) such that the most common cause of mortality is progressive cardiomyopathy. Despite imaging evidence of progressive cardiomyopathy, troponin I (cTn) is not significantly elevated in asymptomatic DMD patients. This study describes eight boys with DMD evaluated for acute chest pain (ACP) and found to have acute cTn elevation with depressed left ventricular ejection fraction (LVEF). Of eight patients, five presented with a primary complaint of ACP, while three presented with secondary myocardial injury in the context of systemic illness requiring hospitalization. Electrocardiograms showed diffuse ST changes and mean peak cTn level was 44±15.4 ng/mL (reference range <0.03 ng/mL). cTn levels normalized with only supportive care. Cardiac magnetic resonance imaging (CMR) was performed during the event on all but one patient, demonstrating increased late gadolinium enhancement (LGE) from 12.4±11.4% to 36.5±10.3% with associated deterioration of LVEF from 61±4.4% to 47.6±6.6% which remained depressed on follow-up CMR study (49.1±7.8%). All viral studies were negative. Additional investigations varied among patients, but no causative findings were demonstrated.
Hor KN, Johnston P, Kinnett K, et al. Progression of Duchenne Cardiomyopathy Presenting with Chest Pain and Troponin Elevation. J Neuromuscul Dis. 2017 Oct 5. doi: 10.3233/JND-170253. [Epub ahead of print]
