Cardiovascular Outcomes During Index Hospitalization in Children with Kawasaki Disease in Ontario, Canada.

Kawasaki disease (KD) is a common childhood vasculitis associated with coronary artery aneurysms (CAA). However, there is limited published data on other cardiovascular events diagnosed during acute KD hospitalizations. Our objectives were to determine the incidence of cardiovascular events during acute KD hospitalizations, stratified by age at admission, CAA status, and pediatric intensive care unit (PICU) admission status. We identified all children (0-18 year) hospitalized with a new KD diagnosis in Ontario, between 1995 and 2018, through validated algorithms using population health administrative databases. We excluded children previously diagnosed with KD and non-Ontario residents. We evaluated for cardiovascular events that occurred during the acute KD hospitalizations, defined by administrative coding. Among 4597 children hospitalized with KD, 3307 (71.9%) were aged 0-4 years, median length of stay was 3 days (IQR 2-4), 113 children (2.5%) had PICU admissions, and 119 (2.6%) were diagnosed with CAA. During acute hospitalization, 75 children were diagnosed with myocarditis or pericarditis (1.6%), 47 with arrhythmias (1.0%), 25 with heart failure (0.5%), and ≤ 5 with acute MI (≤ 0.1%). Seven children underwent cardiovascular procedures (0.2%). Older children (10-18 years), children with CAA, and children admitted to the PICU were more likely to experience cardiovascular events, compared with children aged 0-4 years, without CAA or non-PICU admissions, respectively. The frequency of non-CAA cardiovascular events during acute KD hospitalizations did not change significantly between 1995 and 2018. During acute KD hospitalizations, older children, children with CAA, and PICU admissions are at higher risk of cardiovascular complications, justifying closer monitoring of these high-risk individuals.