Abstract 4144806: Epidemiology of Venous Thromboembolism and the use of Antithrombotic Strategies in Pediatric Patients with Congenital Heart Disease

Introduction: Pediatric patients with congenital heart disease (CHD) are known to be at risk for venous thromboembolism (VTE). However, data describing the rate of recurrent VTE, types of cardiac surgery, and types/locations of index VTE are limited. Aim: The objectives of this study were to determine the rate of incident and recurrent VTE in pediatric patients with CHD undergoing cardiac surgery and evaluate the type of index surgery, index VTE location/site, and antithrombotic therapies. Methods: We queried the TriNetX Research database for patients under the age of 18 years from July 2016 to May 2024, who had a diagnosis of CHD and an index VTE. Descriptive statistics were employed. Results: Of 26,792 pediatric patients who underwent congenital cardiac surgery, 2225 (8.3%) developed an index VTE. Septal defect repair (n=574, 25.8%), shunt placement (n=502, 22.6%) and correction of single ventricle/complex cardiac anomaly (n=389, 17.5%) were the most common index cardiac surgeries in patients who developed index VTE. Lower extremity VTE (n=1219, 54.8%) was the most common type of index VTE. Unfractionated heparin (n=1441, 64.8%) was the most commonly utilized antithrombotic drug for index VTE treatment. Five hundred seventy-nine (26%) patients who underwent cardiac surgery developed at least 1 recurrent VTE within 1 year of the index VTE. Conclusions: Among pediatric patients with CHD that requires cardiac surgery, the rate of incident and recurrent VTE is higher than previously expected. Multicenter prospective cohort studies are warranted to further evaluate the rate of, and risk factors for, recurrent VTE, to facilitate future risk-stratified trials of antithrombotic therapy approaches in these children.