Major Adverse Events of Cardiac Catheterization in Pediatric Cardiomyopathy: Insights From the IMPACT Registry

Background Despite the role of cardiac catheterization for hemodynamic assessment and endomyocardial biopsy in children with cardiomyopathy, data on procedure‐related major adverse events (MAE) in this population are lacking. We aim to describe the rate of MAE in children with cardiomyopathy undergoing cardiac catheterization. Our secondary objective is to compare the rate of MAE among patient subsets within this population. Methods We included patients with cardiomyopathy from the National Cardiovascular Data Registry IMPACT (Improving Pediatric and Adult Congenital Treatment) who were 18 years old or younger and underwent cardiac catheterization between April 2016 and December 2024. Data collected included demographic, preprocedural, procedural, and outcome‐related variables. We performed univariate and multivariate analyses to identify variables independently associated with MAE. Results A total of 4932 procedures were evaluated, with a median age of 10 years. Dilated cardiomyopathy was the most prevalent cardiomyopathy in 53.4%. The rate of MAE was 3.17%. The most common MAE was arrhythmia, representing 42.3% of all MAE. The multivariate analysis also revealed that age <1 year, hypertrophic cardiomyopathy compared with dilated cardiomyopathy, preprocedural inotropic support, left femoral venous access, and systemic heparinization were associated with an increased rate of MAE. In contrast, procedures performed electively were associated with a lower risk of MAE. Conclusions Cardiac catheterization in pediatric patients with cardiomyopathy was associated with low incidence of MAE as compared with the general pediatric population. Factors associated with an increased rate of MAE include age <1 year, hypertrophic cardiomyopathy, inotropic support, left femoral venous access, and systemic heparinization.