Risks of incident venous thromboembolism, recurrent thromboembolism, and use of antithrombotic therapies among children with congenital heart disease undergoing cardiac surgery: a global multicenter analysis of real-world data.

Background: Data on the characteristics and antithrombotic treatments of venous thromboembolism (VTE) among children with congenital heart disease undergoing cardiac surgery are limited.

Objectives: We aimed to evaluate the features and rates of recurrent thromboembolism in real-world experience using a global multicenter dataset.

Methods: We queried the TriNetX global electronic health record-derived real-world data research platform for patients <18 years of age who underwent cardiac surgery for congenital heart disease with a diagnosis of VTE within 1 year of surgery. Data on patient and VTE characteristics, antithrombotic therapies, and recurrent thromboembolism were descriptively analyzed.

Results: Of 24 879 children, 1475 (5.9%) developed an acute incident VTE within 1 year of surgery. Lower extremity deep venous thrombosis (n = 999, 67.7%) was the most common VTE type, and the Glenn procedure was the most common surgery type (n = 432, 29.3%). Unfractionated heparin was utilized for acute (<7 days after diagnosis) and subacute (≥7 days to 3 months after diagnosis) VTE treatment in 1022 (69.3%) and 895 (60.7%) patients, respectively. The 1-year rate of recurrent thromboembolism was high (n = 372, 25%), most of which were lower extremity deep venous thrombosis (n = 305, 81.9%).

Conclusion: Approximately 6% of children undergoing cardiac surgery develop VTE within 1 year. The 1-year risk of thromboembolism recurrence is 25%. Prospective multicenter studies are essential to identify factors associated with the occurrence and recurrence of VTE in children undergoing cardiac surgery. This research will provide valuable insights for future interventional trials focused on preventing incident and recurrent VTE in this vulnerable population.