Objective: To determine whether patients with Kawasaki disease have a higher death rate than an age-matched healthy population after disease occurrence.
Study design: From July 1, 1982, to December 31, 1992, 52 collaborating hospitals collected data on all patients with a new definite diagnosis of Kawasaki disease. Patients were followed up until December 31, 1999, or death. The expected number of deaths was calculated from Japanese vital statistics data and compared with the observed number.
Results: Of 6576 patients enrolled, 27 (19 male, 8 female) died. The standardized mortality ratio (the observed number of deaths divided by the expected number of deaths based on the vital statistics in Japan) was 1.25 (95% confidence interval, 0.84-1.85). Despite the high standardized mortality ratios during the acute disease phase, the mortality rate was not high after the acute phase for the entire group of patients. Although the standardized mortality ratio after the acute phase was 0.76 for those without cardiac sequelae, 6 male patients (no female patients) with cardiac sequelae died during this period, and the standardized mortality ratio for the male group with cardiac sequelae was 2.35 (95% confidence interval, 0.96-5.19).
Conclusions: Although it was not statistically significant, the mortality rate among male patients with cardiac sequelae due to Kawasaki disease seemed higher than that in the general population. On the other hand, mortality rates for female patients with sequelae and both male and female patients without sequelae were not elevated.