Do selection criteria for children with dilated cardiomyopathy enrolled in national registries explain differences in outcomes?

Multi-center studies are necessary to examine the clinical course of childhood cardiomyopathy due to the heterogeneous nature and relatively low prevalence of the disease. Outcomes vary widely and are difficult to predict based on diagnosis, etiology, and presentation. Results from two national studies have enhanced our understanding of the epidemiology and natural history of childhood DCM but differences in outcome exist between these large cohorts. Herein, we summarize these differences with respect to cardiac recovery and transplant-free survival. The potential impact of differences in study design and cohort selection is highlighted.