Background:
With the advent of disease-modifying therapies and advances in clinical care for Duchenne muscular dystrophy (DMD), including non-invasive ventilation, cardiac complications have emerged as the leading cause of mortality. Sudden unexpected deaths in young DMD patients without significant cardiac or lung involvement have been reported with an incidence of up to 19%. Despite their frequency, little is known about the sequence of events leading to such deaths, and guidelines aimed at prevention do not exist.
We defined the term sudden unexpected death in DMD (SUD-DMD) as a natural death that occurred unexpectedly in a DMD patient without evidence of moderate or severe cardiac involvement or restrictive lung disease.
Objectives:
To perform a retrospective chart review of mortality in our center’s DMD population 21 years of age or younger over the last 10 years and characterize clinical features associated with SUD-DMD.
Results:
Twenty-one deaths occurred in our population. Details regarding the deaths of three patients were not available. Ten patients died suddenly (56%); of these, five patients met the definition for SUD-DMD (28%). Compared with DMD patients with known cardiac or respiratory involvement, SUD-DMD patients had a younger median age at death (12 years vs 17), were more often ambulatory (60% vs 12%), and were more likely to be receiving steroids at time of death (100% vs 54%). All SUD-DMD patients had mild preceding viral or nonspecific “prodromal” symptoms.
Conclusions:
The incidence of sudden death at our center was 56%, with 28% meeting our definition of SUD-DMD. All cases involved preceding viral or other nonspecific symptoms, underlining the potential of adrenal crisis as a contributor along with fatal tachyarrhythmias. Patients/caregivers should be counseled regarding the risk of sudden death, and further studies are needed to optimize care guidelines for sick/stress steroid management and arrhythmia risk stratification and prevention.