Follow‐up of Kawasaki disease based on the nationwide survey data in Japan

Background The long-term prognosis of those with a history of Kawasaki disease is still unknown. Methods Using permanent registry system in Japan named koseki, 6576 persons with a history of Kawasaki disease were followed up, of which average follow-up period of time was 30 years. The endpoint was deaths. Results With 99.5% of follow-up rate, 68 deaths (48 males and 20 females) were observed. The overall standard mortality ratio, of which reference was vital statistics in Japan, was not elevated, but that for those with cardiac sequalae due to Kawasaki disease was significantly high. Nine persons, all of which were males, died of Kawasaki disease including suspected, but all of age at deaths were under 20 years. Conclusions This study revealed the long-term prognosis of Kawasaki disease, but almost all participants were younger than 40 years. Continuing follow-up of this cohort is required to clarify whether the history of Kawasaki disease promote atherosclerosis when they become middle aged or older.