Diagnosis of coronary artery abnormalities in Kawasaki disease: recent guidelines and z score systems

Kawasaki disease, an acute systemic vasculitis affecting children, is the leading cause of acquired heart disease in developed countries. This vasculitis has a predilection for the coronary artery, and coronary artery abnormalities are the main criteria for its diagnosis. The diagnosis of coronary abnormalities has historically been based on dichotomous criteria, but recent guidelines have accepted the body surface area-adjusted z score system to define coronary abnormalities and classify coronary artery aneurysms. Z score systems have improved risk classifications of coronary aneurysms and improved correlations with clinical prognosis. However, the discrepancy of calculated z scores according to the formula has been noticed in the application of the z score system, which is possibly related to the diagnosis of coronary artery abnormalities. This variability was greater in larger coronary aneurysm dimensions. A careful choice of the z score formula and its consistent use is needed in clinical applications.