Within the guideline-recommended 30-50 mg/kg/day window, no significant differences were detected between low- and high-dose aspirin in coronary or IVIG non-response outcomes, while the lower dose halved adverse drug reactions.
Key Findings
Results
Coronary artery lesion rates at 4 weeks were similar between low-dose and high-dose aspirin groups.
CAL at 4 weeks occurred in 13.5% of the low-dose group (30 to <40 mg/kg/day; n=630) and 14.7% of the high-dose group (40 to 50 mg/kg/day; n=367).
The difference was not statistically significant (P=0.658).
Adjusted OR was 0.94 (95% CI 0.64-1.38; P=0.752) in the multivariable model.
IPTW sensitivity analysis yielded an OR of 0.95 (95% CI 0.65-1.38), and the doubly robust estimate was 0.95 (95% CI 0.65-1.40).
The multivariable model included 7 predictors with 136 CAL events, yielding an events-per-variable ratio of 19.4.
Results
There was no significant dose-response relationship between aspirin dose and coronary artery lesion outcomes across the 30-50 mg/kg/day range.
The dose-response relation was examined using restricted cubic splines.
The spline showed no significant linear trend (P=0.253) or non-linear trend (P=0.547).
This analysis covered the full guideline-recommended dosing range of 30-50 mg/kg/day.
Results
IVIG non-response rates were similar between the low-dose and high-dose aspirin groups.
IVIG non-response occurred in 4.1% of the low-dose group versus 3.8% of the high-dose group.
The difference was not statistically significant (P=0.940).
This suggests that aspirin dose within the guideline range does not influence IVIG treatment response.
Results
Aspirin-related adverse drug reactions were significantly more frequent in the high-dose group, occurring at approximately twice the rate of the low-dose group.
Adverse drug reactions occurred in 3.0% of the low-dose group versus 6.3% of the high-dose group.
The difference was statistically significant (P=0.021).
The lower dose (30 to <40 mg/kg/day) halved the rate of adverse drug reactions compared to the higher dose (40 to 50 mg/kg/day).
Methods
The study retrospectively analyzed 997 children with Kawasaki disease treated at two tertiary hospitals in Sichuan, China, over approximately eight years.
The cohort included children with complete or incomplete KD from January 2017 to December 2025.
630 children received low-dose aspirin (30 to <40 mg/kg/day) and 367 received high-dose aspirin (40 to 50 mg/kg/day), both in combination with IVIG.
Confounders were selected by intersecting a directed acyclic graph with univariate screening at P<0.10, yielding a final multivariable model of 7 predictors.
Linearity of continuous covariates and absence of multicollinearity were verified.
Conclusions
The authors conclude that 30 to <40 mg/kg/day may be the preferable aspirin dose during the acute phase of Kawasaki disease in Chinese children.
This conclusion is based on equivalent coronary and IVIG non-response outcomes combined with a significantly lower rate of adverse drug reactions in the low-dose group.
The authors note that 'equivalence cannot be formally demonstrated in an observational study.'
Chinese guidelines currently recommend a broader range of 30-50 mg/kg/day, leaving dose selection within this range to clinical discretion.
The data suggest the lower portion of the guideline range achieves comparable efficacy with improved safety.
What This Means
Kawasaki disease is a condition that causes inflammation of blood vessels in children, and its most serious complication is damage to the coronary arteries (the arteries that supply blood to the heart). Treatment typically involves intravenous immunoglobulin (IVIG) combined with aspirin. Chinese medical guidelines recommend aspirin doses of 30-50 mg per kilogram of body weight per day during the acute phase, but it was not previously clear whether using doses at the lower or higher end of this range made a difference in outcomes. This study examined nearly 1,000 children treated at two hospitals in China to compare outcomes between lower-dose aspirin (30 to <40 mg/kg/day) and higher-dose aspirin (40 to 50 mg/kg/day).
This research suggests that within the guideline-recommended dose range, the two groups had nearly identical rates of coronary artery damage (about 13-15% in both groups) and similar rates of not responding to IVIG treatment (about 4% in both groups). These results held up across multiple statistical methods, including analyses designed to account for differences between the two patient groups. However, children who received the higher aspirin dose experienced aspirin-related side effects at roughly twice the rate of those receiving the lower dose (6.3% vs. 3.0%).
This research suggests that using the lower portion of the recommended aspirin dose range (30 to <40 mg/kg/day) may offer similar protection against coronary artery complications while causing fewer side effects in children with Kawasaki disease. The authors caution that because this was an observational study looking back at medical records rather than a controlled experiment, formal proof of equivalence between the doses cannot be established, and further research would be needed to confirm these findings.
Zhao B, Ai L, Huang H, Liu Y, Ma H, Gao Q, et al.. (2026). Aspirin dose and coronary artery lesions in Kawasaki disease: a two-center retrospective comparative effectiveness study.. European journal of pediatrics. https://doi.org/10.1007/s00431-026-07521-1