Rivaroxaban for Children Aged Over 2 Years With Giant Coronary Artery Aneurysms After Kawasaki Disease

Based on population pharmacokinetic model-based simulation, a 15 mg-equivalent, age-, and bodyweight-adjusted dosing regimen for Chinese children with giant coronary artery aneurysms after acute Kawasaki disease was proposed. This exploratory trial aims to evaluate the feasibility, safety and effectiveness of rivaroxaban compared to warfarin for thromboprophylaxis in children aged over 2 years with giant coronary artery aneurysms after Kawasaki disease

Lifelong anticoagulant treatment is required in children with giant coronary artery aneurysm after Kawasaki disease, imposing social and psychologic burdens on patients and parents. Rivaroxaban is a potential oral anticoagulant in this population. Considering the impact of ethnic difference and growth development, we proposed a Chinese-specific, optimized dosing regimen based on model- and clinical evidence-informed precision dosing. In the previous pilot study, this optimized dosing regimen demonstrated a favorable feasibility among 11 Chinese pediatric patients aged over 2 years with giant coronary artery aneurysm after Kawasaki disease, with no thrombosis or major bleeding over 6 months. This study is a multicenter, open-label, exploratory, randomized controlled trial to evaluate the feasibility, safety and effectiveness of rivaroxaban for thromboprophylaxis in children aged over 2 years with giant coronary artery aneurysms after Kawasaki disease, following the 15 mg-equivalent dosing regimen. Participants will be randomly assigned to the control or experimental groups. Randomization ratio will be 2:1. The control group will receive warfarin plus aspirin or clopidogrel, and the experimental group will receive rivaroxaban plus aspirin or clopidogrel. Baseline characteristics, treatment effect outcomes, bleeding events, adverse events and compliance of intervention of each participant will be collected. Because this is an exploratory study and the low incidence of giant coronary artery aneurysm in children with Kawasaki disease, the study plans to recruit 100 participants. The aims include: * The feasibility * The safety and efficacy profile of the optimized, 15 mg-equivalent dosing regimen * The group differences in safety and treatment effect between warfarin and rivaroxaban