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.

111 Kawasaki disease in Ontario children from 1995-2017: A population-based descriptive analysis

Background

Kawasaki disease (KD) is a common pediatric vasculitis with rising global incidence. Associated coronary artery aneurysms (CAA) can result in significant long-term morbidity and mortality. However, our understanding of the trends in incidence along with patient and disease characteristics for North American children over the past two decades remains limited, particularly in universal health care systems. This understanding can inform healthcare resource planning and identify knowledge gaps for educational initiatives.

Objectives

The objectives of this study were to: 1) compare patient, hospital and disease characteristics for children diagnosed with KD between two eras (1995-2001 and 2002-2017) and three age groups (0-4yr, 5-9yr, 10-18yr) and 2) determine trends in KD incidence across Ontario, Canada between 1995 to 2017.

Design/Methods

We used healthcare administrative databases housed at the Institute for Clinical Evaluative Sciences (ICES) to identify a population-based cohort of Ontario children (0-18 years) diagnosed with KD during hospital admission between April 1995 and March 2017. We excluded children with previous KD diagnosis. We compared eras and age groups by Chi-squared test. We determined the annual incidence of KD in Ontario, compared by Cochrane-Armitage test.

Results

We identified 4346 Ontario children diagnosed with KD between 1995-2017. The mean (SD) age at diagnosis was 3.4 years (± 2.9) and male:female ratio was 1.5:1. Median (IQR) length of hospital admission was 3 days (2-4) and 104 children (2.4%) required PICU admission. No child died within 90 days of diagnosis. Baseline CAA were observed in 106 children (2.4%). There was no difference in baseline CAA by era (2.3% [1995-2001] vs 2.5% [2002-2017], p=0.72). CAA were significantly more common in children aged 10-18 years (5.3% vs 2.4% [0-4yr] and 2.2% [5-9yr], p=0.03). Myo-/pericarditis occurred in 71 children (1.6%). Red blood cell transfusions were administered to 51 children (1.2%) and were significantly more common during 2002-2017 (≤0.5% vs 1.5%, p<0.001). The standardized incidence of KD increased significantly over the study period (p<0.0001), from 6.5 cases per 100,000 person-years (1995-2000) to 8.4 cases (2012-2017). Significant seasonal variation was observed; incidence was highest from November to March (OR 1.7 – 2.1, using August as reference month) and peaked in January (OR 2.1).

Conclusion

The incidence of KD has increased significantly over the past 20 years in Ontario, Canada which may reflect increased awareness and improved diagnosis. However, the frequency of baseline CAA has not changed. Baseline CAA are more common in children 10-18 years. This may suggest delayed diagnosis in this age group.