Abstract 4134590: Procedural Related Major Adverse Events of Cardiac Catheterization in Pediatric Patients with Cardiomyopathy: Insights from IMPACT Registry

Background: Despite the role of cardiac catheterization for hemodynamic assessment and endomyocardial biopsy (EMB) in children with cardiomyopathy, data on procedure-related major adverse events (MAE) in this population is 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. Hypothesis: We hypothesize that the rate of MAE will vary among cardiomyopathy types and that EMB will be associated with an increased rate of MAE. Methods: We included patients with cardiomyopathy from the National Cardiovascular Data Registry Improving Pediatric and Adult Congenital Treatment (IMPACT) who were 18 years or younger and had cardiac catheterization from April 2016 to June 2023. We collected demographic, pre-procedural, procedural, and outcome-related variables. We performed univariate and multivariate analyses to identify variables independently associated with MAE. Results: A total of 15,656 procedures were evaluated, with a median age of 11 years; 50.3% were females. Dilated cardiomyopathy (DCM) was the most prevalent cardiomyopathy in 68%, followed by restrictive cardiomyopathy (RCM) in 14% and hypertrophic cardiomyopathy (HCM) in 9%. MAE was present in 1.6%. The most common MAE was arrhythmia, representing 46% of MAE, followed by cardiac arrest and bleeding each 20%. EMB was associated with a lower rate of MAE in univariate analysis p<0.001. The association between a lower rate of MAE and EMB persisted in the multivariate model when those with heart transplant who had EMB were compared to those without heart transplant who did not have EMB p=0.001. The multivariate analysis also revealed that age less than a year, HCM compared to DCM, history of heart failure, pre-procedural inotropic support, and non-elective procedure were associated with increased rate of MAE. The overall mortality rate was 1.66%. The leading cause of mortality was heart failure in 51% of deceased patients. MAE was associated with an increased mortality rate of 11% p<0.001. Conclusion: Cardiac catheterization is a safe procedure in pediatric patients with cardiomyopathy, with an overall MAE rate of 1.6%. Age of less than a year, HCM, history of heart failure, and prior inotropic support are associated with an increased rate of MAE. EMB was not associated with a higher rate of MAE. MAE occurrence is associated with a sevenfold increase in mortality rate.