Childhood dilated cardiomyopathy carries a high risk of death or transplantation in the first year (26%), but risk drops to ~1% per year thereafter, with most survivors doing well off cardiac medications.
Death or transplantation occurred in 26% of patients with childhood dilated cardiomyopathy within 1 year of diagnosis and ~1% per year thereafter. Risk factors for death or transplantation include age at diagnosis, familial cardiomyopathy, and severity of left ventricular dysfunction. The majority of surviving subjects are well and free of cardiac medication.
Alexander et al. (Sat,) studied this question.