Clinical Significance of a New Z-Score Calculator in Pediatric Patients With Kawasaki Disease

This study examined the real-world impact of simultaneous dual Z-score reporting on the interpretation of coronary dilation in Kawasaki disease (KD). Two widely used reference systems exist for evaluating coronary artery dimensions in children: Boston Children's Hospital (Boston) and Pediatric Heart Network (PHN). We retrospectively reviewed KD echocardiograms performed at a single institution between January 2019 and November 2021; 47 KD patients were included. The PHN Z-scores for the left main coronary artery (LMCA) and left anterior descending (LAD) were larger than those of Boston, resulting in 15% of LAD and 13% of LMCA measurements classified as dilated by PHN but normal by Boston. Among discordant echocardiograms, cardiologists were evenly split on which system was cited, with 2 incomplete KD diagnoses confirmed solely on LAD dilation identified by PHN. Coronary normalization took a mean of 33 days by PHN vs 12 days by Boston. Simultaneous dual reporting introduces clinically meaningful discordance, warranting guideline standardization.