DescriptionBackground: Pediatric cardiomyopathy (CM) is a rare condition with significant childhood morbidity and mortality. There are various causes of pediatric CM including both genetic and environmental factors. Previous research in the genetics of pediatric cardiomyopathy has focused on identifying variants for diagnostic purposes. However, the presence of a pathogenic variant alone is insufficient to predict clinical outcome and risk for adverse events in this population.
Purpose: The purpose of this study was to explore whether CardioBoost, a new disease-specific pathogenicity predictor, could be used to better stratify disease severity in pediatric CM. This study was modeled after a recent study that found that variants classified as disease causing by CardioBoost were associated with both disease status and an increased risk for severe clinical outcomes in adults with cardiomyopathy (Zhang et al., 2021).
Methods: This was a retrospective, single-center cohort study that evaluated outcomes in pediatric patients (age <21 at the time of diagnosis) with a history of cardiomyopathy (including dilated, hypertrophic, restrictive, left ventricular non-compaction, and arrhythmogenic right ventricular) who were evaluated by the Children’s Hospital of Philadelphia (CHOP) Cardiomyopathy Program between 2010 and 2018. Cardiomyopathy was categorized as dilated (DCM), hypertrophic (HCM), or Other (restrictive, left ventricular non-compaction, or arrhythmogenic right ventricular). CardioBoost scores were generated for patients who meet study criteria and CardioBoost eligibility. Scores were categorized as <=1, 1-9, and >=9. Composite endpoint was freedom from a major adverse cardiac event (MACE).
Results: 104 patients were included in the final analysis, of which 32 (31%) had DCM, 45 (43%) had HCM, and 27 (26%) had Other. We did not identify any associations between CardioBoost (CB) score and clinical outcome in patients with pediatric CM.
Conclusion: Overall, this study speaks to the continued deficits in variant interpretation for pediatric cardiomyopathy. We recommend using caution when applying this tool to stratify clinical outcomes in the pediatric population.