Rethinking thrombophilia testing in pediatric VTE: A decade of real-world evidence

Background: The clinical utility of routine thrombophilia testing to guide management in pediatric venous thromboembolism (VTE) is debated. This study sought to evaluate the real-world impact of thrombophilia testing on anticoagulation duration and clinical outcomes. Methods: We conducted a 10-year retrospective cohort study of 67 pediatric patients with VTE. We analyzed the association between thrombophilia status and anticoagulation duration, VTE recurrence, and thrombus resolution on follow-up imaging. Results: The majority of VTE events (80.6 %) were provoked. A positive thrombophilia workup did not significantly alter the median anticoagulation duration compared to a negative workup (p = 0.582). A positive thrombophilia status was not a significant predictor of VTE recurrence in survival analysis (HR 2.22, p = 0.281). However, a positive workup was significantly associated with a higher rate of Residual Vein Obstruction (RVO) (73.3 % vs. 36.4 %, p = 0.045). This imaging finding did not, in turn, predict VTE recurrence (p = 0.388). Conclusion: Thrombophilia testing did not influence treatment duration or predict recurrence. Our findings provide real-world evidence supporting current guidelines that advocate for a selective, clinically driven approach to testing rather than its routine use after a first pediatric VTE.