Miura M, et al. - The correlation between the z score with time-dependent coronary event (CE) occurrence was determined in patients with Kawasaki disease (KD) and coronary artery aneurysms (CAAs) younger than 19 years of age who underwent coronary angiography between 1992 and 2011. The 10-year event-free survival rate for CE was 100%, 94%, and 52% in males and 100%, 100%, and 75% in females for small, medium, and large CAAs, respectively. With respect to the estimation of the severity of CAAs in relation to the time-dependent occurrence of CE and associated factors, classification using the internal diameter z score was beneficial in patients with KD. For such patients, cautious management of CE is recommended, particularly for males and intravenous immunoglobulin-resistant patients with a large CAA.