Background: The aim of this study was to explore the associations between the aspartate aminotransferase-to-alanine aminotransferase ratio (AST/ALT) and coronary artery lesions (CALs) among patients with Kawasaki disease (KD).

Methods: Medical records of KD patients presenting to a single center between January 2019 and December 2020 were retrospectively collected and analyzed. Univariate, multivariable-adjusted analyses, subgroup analyses, restricted cubic spline test, and fitted curves were used to evaluate the associations between AST/ALT and CALs.

Results: A total of 831 patients were enrolled, of which 201 (24.2%) had CALs on admission and 21 (2.5%) developed CALs de novo after intravenous immunoglobulin (IVIG). Multivariable-adjusted analyses models revealed that a lower AST/ALT was associated with an increased risk of CALs on admission when AST/ALT was a continuous variable (P = 0.007) and when it was a categorical variable (P for trend = 0.004). Each unit increase in AST/ALT was associated with a 22% lower risk of CALs on admission (odds ratio = 0.78, 95% confidence interval 0.65-0.94). A negative linear relationship was noted between AST/ALT and the risk of CALs on admission in both observed and fitted models. However, such associations were not observed in AST/ALT and CALs de novo after IVIG. None of the variables significantly modified the association between AST/ALT and CALs on admission and CALs de novo after IVIG (P > 0.05).