Evaluation of a Kawasaki Disease Risk Model for Predicting Coronary Artery Aneurysms in a Japanese Population: An Analysis of Post RAISE

Objectives: To test the performance of the Son risk score, which was created to predict coronary artery abnormalities from baseline variables in North American patients with Kawasaki disease. Study design: The dataset from Post RAISE, the largest prospective cohort study of Japanese patients with Kawasaki disease to date, was used for the present study. With high risk defined as ≥3 points, sensitivity, specificity, positive predictive value, and negative predictive value for coronary artery abnormality development were calculated. To evaluate the effect of each risk factor in the Son score, the OR and 95% CIs were calculated using logistic regression analysis with the presence of coronary artery abnormality at 1 month after disease onset. Results: Post RAISE enrolled 2628 consecutive patients with Kawasaki disease, and 304 patients had a high-risk score, of whom 15.1% showed coronary artery abnormality. At the cutoff ≥3 points, the sensitivity was 37.7%, and the specificity was 87.2%. The maximum z score at baseline ≥2.0 (OR 3.5, 95% CI 2.3-5.2) and age <6 months at disease onset (OR 3.2, 95% CI 1.9-5.4), were significantly associated with coronary artery abnormality development. However, a high concentration of C-reactive protein was not associated with coronary artery abnormality. The area under the receiver operating characteristic curve for the Son score was 0.65 (95% CI 0.59-0.71). Conclusions: The Son score had insufficient sensitivity and good specificity in a Japanese cohort of patients with Kawasaki disease. Among the variables comprising the Son score, a large baseline z score and young age at disease onset were significant, independent predictors of coronary artery abnormality development.