Survival and cardiac recovery in pediatric dilated cardiomyopathy: A long–term cohort study of risk factors, prognosis, and health outcomes followed into adulthood

Background: Dilated cardiomyopathy (DCM) is the most common cause of pediatric heart failure (HF), but most studies focus on early survival. We examined prognostic factors and outcomes of routine care in childhood-onset DCM followed into adulthood. Methods: From January 2001 to August 2023, we studied a cohort of patients with childhood-onset DCM using electronic medical records from a tertiary pediatric hospital and linked province-wide health care administrative data. DCM cases with or without echocardiographic recovery and matched controls were compared on demographic and disease characteristics and various health outcomes. We used Cox proportional hazards regression and cause-specific hazard models to identify prognostic factors for all-cause mortality and heart transplantation, respectively. As some recovered cases later died or underwent transplantation, this may constitute DCM relapse. On multivariable analysis, idiopathic and familial DCM (vs myocarditis), lower left ventricular ejection fraction, rural residence, and not receiving HF medications were associated with heart transplantation. Diagnosis in 2010-2017 (vs 2001-2009), recovery, beta blockers, and the lack of troponin I or T mutations were protective against mortality. Conclusions: Childhood DCM is associated with adverse health and increased health care utilization even into adulthood. While echocardiographic normalization and routine treatments are associated with improved prognosis, some patients may relapse after recovery.