Coronary Artery Outcomes in Kawasaki Disease by Treatment Day Within 10 Days of Fever Onset

Background. Kawasaki disease (KD) is an acute febrile illness of childhood that can lead to coronary artery aneurysms (CAAs) and myocardial infarction. Intravenous immunoglobulin reduces the prevalence of CAA when given to patients with KD within 10 days of fever onset. Children with KD may undergo evaluation for other diagnoses before treatment, particularly those with incomplete KD criteria. If KD outcomes are improved with early treatment, a delay in treatment while evaluating for other causes might place these patients at risk. Methods. We performed a retrospective cohort study of children treated for KD within the first 10 days of illness at our KD center from 2014 to 2021 to determine the prevalence of CAA by day of treatment. Results. A total of 290 patients met the study criteria. No statistically significant difference was found in the odds of developing a maximum z score ≥2.5 for each day of delayed treatment within 10 days of fever onset (adjusted odds ratio, 0.87; 95% CI, .72–1.05; P = .13). Subgroup analyses by age, sex, and year of treatment did not reveal a significant association between treatment day and maximum z score ≥2.5, although the number of patients <6 months of age was small. Conclusions. Our study supports current recommendations. We found similar odds of developing adverse coronary outcomes regardless of treatment day within 10 days from fever onset.