Older age is a risk factor for the development of cardiovascular sequelae in Kawasaki disease

Objectives. To clarify the characteristics of Kawasaki disease (KD) in children 6 years and older and to determine whether age is a risk factor for cardiovascular abnormalities. Methods. Patients who had KD and were reported between 1999 and 2000 in the 16th nationwide survey of KD in Japan (n=15314) were analyzed. Patients who were aged 6 years or older (older group) were matched with patients who were aged 6 months to 3 years and were treated at the same hospital (younger groups). The total number of analyzed patients was 1498 (749 matched pairs). Results. The proportion of complete KD in the older group was similar to that in the younger group. Recurrent cases in the older group were significantly more common than those in the younger group (9% vs 2%). The proportion of patients who were treated with intravenous gamma-globulin in the older group was significantly lower than that in the younger group (82% vs 87%). The proportion of older group patients who were treated with intravenous gamma-globulin at or after 7 days of illness was significantly higher than that in the younger group (35% vs 14%). There was a higher prevalence of cardiovascular abnormalities in the older group than in the younger group (20% vs 15%). Multivariate logistic regression analysis showed that older age was an independent risk factor for cardiovascular sequelae (odds ratio: 1.58; 95% confidence interval: 1.01-2.46). Conclusions. In children older than 6 years, age is an independent risk factor for cardiovascular sequelae in KD.