Coronary Artery Aneurysm Measurement and Z Score Variability in Kawasaki Disease

• Published in: Journal of the American Society of Echocardiography Vol. 29; no. 2; pp. 150 - 157
• Main Authors: Ronai, Christina, Hamaoka-Okamoto, Akiko, Baker, Annette L., de Ferranti, Sarah D., Colan, Steven D., Newburger, Jane W., Friedman, Kevin G.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2016
• Subjects: Cardiovascular; Child; Child, Preschool; Coronary aneurysm; Coronary Aneurysm - diagnostic imaging; Coronary Aneurysm - physiopathology; Echocardiography; Echocardiography - methods; Female; Humans; Infant; Kawasaki disease; Male; Mucocutaneous Lymph Node Syndrome - diagnostic imaging; Mucocutaneous Lymph Node Syndrome - physiopathology; Reproducibility of Results; Z scores; Coronary aneurysm; BSA; RCA; Z scores; CAA; Kawasaki disease; Echocardiography; KD; AHA; LMCA; CA; LAD; Coronary artery; Left anterior descending coronary artery; Coronary artery aneurysm; American Heart Association; Right coronary artery; Body surface area; Left main coronary artery
• ISSN: 0894-7317; 1097-6795
• DOI: 10.1016/j.echo.2015.08.013

Coronary artery (CA) Z scores are commonly used for clinical decisions in Kawasaki disease, including treatment, anticoagulation, and duration and frequency of follow-up. The aim of this study was to evaluate CA measurement reproducibility, Z score calculation variability, and the impact of variability on management. Twenty-one patients with Kawasaki disease with right CA (RCA) or left anterior descending CA (LAD) Z scores of 1.5 to 3 (group 1) were randomly selected, and all patients with Kawasaki disease with Z scores of 7 to 14 for either the RCA or LAD (n = 20; group 2) were included from March 2008 to May 2014. Two echocardiographers measured left main CA, LAD, and RCA dimensions. The inter- and intraobserver reliability of absolute measurements was calculated, and the CA Z scores derived from three commonly used formulas were compared. Median age at echocardiography was 1.2 years (range, 0.2–11.5 years), and 68% of subjects (n = 28) were male. Interobserver reliability was high for the LAD (intraclass correlation coefficient [ICC], 96.79%) and RCA (ICC, 93.31%) and lower for the left main CA (ICC, 73.54%). Intraobserver reliability was also high for the LAD and RCA (ICC, 99.08% and 97.74%) and lower for the left main CA (ICC, 80.88%). Calculated Z scores were similar among the three formulas for group 1 but varied markedly in group 2. Calculated Z scores using the same CA measurement in each of the three formulas resulted in different clinical management in up to seven of 21 group 1 patients (22%) and in up to 10 of 20 group 2 patients (50%). Although CA measurements have high inter- and intraobserver agreement, CA Z scores vary dramatically on the basis of the Z score formula at larger CA dimensions. Discrepancies in CA Z score calculators may affect clinical decision making. •Calculated Z scores were similar among the three formulas for coronary artery Z scores of 1.5 to 3.•Calculated Z scores varied markedly among the three formulas for coronary artery Z scores of 7 to 14.•Discrepancies in CA Z score calculators may affect clinical decision making.