Comparative efficacy and safety of rivaroxaban versus warfarin in patients following pulmonary valve replacement: a randomized controlled trial

Background Pulmonary valve replacement (PVR) in pediatric and young adult populations necessitates effective thromboprophylaxis due to the potential risk of thromboembolic complications. Warfarin, though traditionally used, presents limitations in children due to its narrow therapeutic range and the need for frequent INR monitoring. Rivaroxaban, a direct oral anticoagulant (DOAC), has shown promise in pediatric thrombosis prevention but its safety and efficacy after PVR have not been established. Methods In this randomized, double-blind clinical trial, 44 patients aged over 5 years ( The minimum age of our patient was 9 years old) who underwent PVR at a tertiary referral center were randomized to receive either warfarin (0.1–0.3 mg/kg/day with INR monitoring) or rivaroxaban (dosed as Mayo Clinic pediatric guidelines). Patients with prior thrombosis, paradoxical embolism, low ejection fraction, or hypersensitivity to study medications were excluded. Patients were followed for a mean of approximately 6 months, assessed for thromboembolic or hemorrhagic events, and rated their satisfaction with anticoagulation on a 10-point scale. Three patients were lost to follow-up, and 41 were included in the final analysis (warfarin: n = 22; rivaroxaban: n = 19). Results No thromboembolic or cerebrovascular events were observed in either group. One patient (4.54%) in the warfarin group developed hemoptysis, later attributed to an arteriovenous malformation, which resolved upon switching to rivaroxaban. Patient satisfaction was significantly higher in the rivaroxaban group (mean score: 8.26 ± 1.99) compared to the warfarin group (5.14 ± 1.09; p < 0.001). Baseline demographics were similar between groups except for weight, which was significantly higher in the rivaroxaban group ( p = 0.044). Conclusion Rivaroxaban demonstrated comparable efficacy to warfarin in preventing thromboembolic events following PVR in children and young adults, with a favorable safety profile and significantly higher patient satisfaction. These findings support further evaluating rivaroxaban as a viable anticoagulation option in this population. Trial registration Registered in the Iranian Registry of Clinical Trials (IRCT): IRCT20220516054868N2. Registration date: 11/30/2023.