Predictors of severe coronary involvement in children with Kawasaki disease: a single-centre cohort study

Kawasaki disease is the leading cause of acquired heart disease in children. Coronary artery involvement determines long-term outcomes, yet early identification of patients at risk for severe disease remains challenging.

We conducted a retrospective, single-centre cohort study of 104 children diagnosed with Kawasaki disease between January 2009 and April 2025. Clinical, laboratory, treatment-related, and echocardiographic data were collected. Coronary artery Z-scores were calculated using standardized equations and classified according to the 2017 American Heart Association criteria. Severe Kawasaki disease was defined as a baseline coronary Z-score ≥ 5.0. Longitudinal coronary changes were analysed in severe cases. Univariable and restricted multivariable logistic regression analyses were performed to identify independent predictors.

Ten patients (9.6%) met the criteria for severe Kawasaki disease. Severe cases were younger and experienced longer diagnostic delays and prolonged fever before intravenous immunoglobulin administration. Baseline coronary Z-scores were significantly higher in the severe group (median 8.95 vs. 2.35, p < 0.001). Severe disease was associated with hypoalbuminaemia, anaemia, thrombocytosis, delayed inflammatory resolution, and increased treatment intensity. In multivariable analysis, delayed intravenous immunoglobulin treatment and baseline pericardial effusion independently predicted severe coronary involvement, while higher serum albumin levels were protective. Although coronary Z-scores declined during follow-up, persistent abnormalities were observed in 60% of severe cases.

Severe coronary involvement in Kawasaki disease is associated with delayed treatment and increased systemic inflammation. Baseline pericardial effusion and hypoalbuminaemia identify high-risk patients. Early recognition and timely treatment may improve cardiac outcomes.