Kawasaki disease is a pediatric acute systemic vasculitis that specifically involves the coronary arteries. Timely initiation of immunoglobulin plus aspirin is necessary for diminishing the incidence of coronary artery abnormalities (CAAs). The optimal dose of aspirin, however, remains controversial. The trial aims to evaluate if low-dose aspirin is noninferior to moderate-dose in reducing the risk of CAAs during the initial treatment of Kawasaki disease.

This is a multi-center, prospective, randomized, open-label, blinded endpoint, noninferiority trial to be conducted in China. The planned study duration is from 2023 to 2026. Data will be analyzed according to intention-to-treat principles. Participants are children and adolescents under the age of 18 with Kawasaki disease, recruited from the inpatient units. A sample size of 1,346 participants will provide 80% power with a one-sided significance level of 0.025. Qualifying children will be randomized (1:1) to receive either intravenous immunoglobulin (2 g/kg) plus oral moderate-dose aspirin (30-50 mg·kg−1·d−1) until the patient is afebrile for at least 48 hours, or immunoglobulin plus low-dose aspirin (3-5 mg·kg−1·d−1) as initial treatment. The primary outcome will be the occurrence of CAAs at 8 weeks after immunoglobulin infusion. Independent blinded pediatric cardiologists will assess the primary endpoint using echocardiography.