Risk Factors of Coronary Artery Aneurysms in Kawasaki Disease with a Low Risk of Intravenous Immunoglobulin Resistance: An Analysis of Post RAISE

Objective: To detect risk factors of coronary artery aneurysm (CAA) development in patients with Kawasaki disease determined to have a low risk for resistance to primary intravenous immunoglobulin (IVIG) treatment based on the Kobayashi score. Study design: This study included 1757 predicted IVIG responders from Prospective Observational study on STRAtified treatment with Immunoglobulin plus Steroid Efficacy for Kawasaki disease (Post RAISE), a large-scale, multicenter, prospective cohort study of Kawasaki disease in Japan. Predicted IVIG responders were defined as patients with Kawasaki disease with a Kobayashi score of <5, a predictive scoring system for IVIG resistance created in Japan. The primary outcome was CAA development at 1 month after disease onset. CAA was defined as a Z score of ≥2.5. Multivariable logistic regression was used to identify the independent risk factors of CAA. The variables for inclusion were identified based on univariate analysis results and previously reported risk factors of CAA. Results: Among 1632 patients who had complete coronary outcome data, CAA developed in 90 patients (5.5%) at 1 month after disease onset. Multivariable analysis found that a baseline maximum Z score of >2.5, age of <12 months at fever onset, and nonresponsiveness to IVIG were significant, independent risk factors of CAA development at 1 month after disease onset. Among the risk factors, a baseline maximum Z score of >2.5 was most strongly associated with CAA development (OR, 7.1; 95% CI, 4.1-12.2; P ≤ .001). Conclusions: Predicted IVIG responders with CAA risk factors identified in this study may be candidates for future clinical trials of intensified primary IVIG treatment with prednisolone, cyclosporine or infliximab.