Real-world use of rivaroxaban for the thromboprophylaxis in Congenital and Acquired Heart Disease: A Prospective Cohort Study

Introduction

Direct oral anticoagulants (DOACs) offer advantages over conventional anticoagulants, including fewer drug-drug interactions, no dietary restrictions, and less monitoring. While recent trials suggest promise for their use in children with congenital or acquired heart disease (CAHD), real-life data in this heterogenous and high-risk population remain scarce. This study aimed to evaluate the real-life efficacy and safety of Rivaroxaban and to identify associated risk factors.

Method

This prospective study included all children enrolled in the DOACs educational program between September 2023 and November 2024. Serious adverse events were defined according to the International Society on Thrombosis and Haemostasis (ISTH) criteria, including thrombotic events, major bleeding events, and clinically relevant non-major bleeding events (CRNM). Statistical analysis was conducted using Cox proportional hazard models.

Results

A total of 105 patients were included, of whom 65 (61.9%) were male. Diagnoses included 74 (70.4%) with Fontan physiology, 18 (17.1%) with cardiomyopathy, 7 (6.8%) with Kawasaki disease and giant aneurysms, and 6 (5.7%) with other conditions (arrhythmia, stroke, coronary fistulae, mitral annulus). The median age at initiation was 9.3 years (IQR: 5.7–13.8), with a median follow-up duration of 6.2 months (IQR: 3.5–9.4). A total of 8 serious adverse events were recorded: one thrombotic event (left pulmonary artery thrombosis) in an adolescent with tetralogy of Fallot following surgical replacement of the right ventricular outflow tract, and one major bleeding event in an adolescent with acute anemia secondary to profuse menometrorrhagia. At 6 months, 91.1% (95% CI [82.9%–95.5%]) of patients remained free of any serious adverse events. Univariate analysis identified female gender as the only risk factor for serious adverse events (HR = 5.8; 95% CI [1.2–28.9]; p = 0.03), with the majority of CRNM events corresponding to severe menometrorrhagia.

Conclusion

DOACs appears to be a feasible and safe therapeutic option for children with CAHD. However, particular attention should be paid to young girls, who exhibit an increased risk of bleeding associated with menstruation. Targeted therapeutic education and specific preventive measures should be incorporated for this subgroup.