Natural History of Dilated Cardiomyopathy in Children.

BACKGROUND: The long-term progression of idiopathic dilated cardiomyopathy (DCM) in pediatric patients compared with adult patients has not been previously characterized. In this study, we compared outcome and long-term progression of pediatric and adult DCM populations.

METHODS AND RESULTS: Between 1988 and 2014, 927 DCM patients were consecutively enrolled. The pediatric population (aged <18 years at enrollment) included 47 participants (5.1%). At presentation, the pediatric population compared with adult patients had a significantly increased occurrence of familial forms (P=0.03), shorter duration of heart failure (P=0.04), lower systolic blood pressure (P=0.01), decreased presence of left bundle-branch block (P=0.001), and increased left ventricular ejection fraction (P=0.03). Despite these baseline differences, long-term longitudinal trends of New York Heart Association class III to IV, left ventricular dimensions, left ventricular ejection fraction, and restrictive filling pattern were similar between the 2 populations. Regarding survival analysis, because of the size difference between the 2 populations, we compared the pediatric population with a sample of adult patients randomly matched using the above-mentioned baseline differences in a 3:1 ratio (141 adult versus 47 pediatric patients). During a median follow-up of 110 months, survival free from heart transplantation was significantly lower among pediatric patients compared with adults (P<0.001). Furthermore, pediatric age (ie, <18 years) was found to be associated with an increasing risk of both death from pump failure and life-threatening arrhythmias.

CONCLUSIONS: Despite the pediatric DCM population having higher baseline left ventricular ejection fraction and similar long-term echocardiographic progression compared with the adult DCM population, the pediatric DCM patients had worse cardiovascular prognosis.