[Histopathological analysis of myocardial damages following Kawasaki disease with repeated endomyocardial biopsy]

Abstract

Since Kawasaki disease was first reported 20 years ago, many investigations about cardiac complications and treatment have been carried out. However, etiology still remains unknown. Although many studies focused on coronary artery lesions (CAL) have been reported, there have been only a few reports of pathological studies on myocardial after-effects of Kawasaki disease using endomyocardial biopsy. In order to investigate the myocardial sequelae, repeated coronary arteriography and endomyocardial biopsy were performed in thirteen patients of Kawasaki disease with coronary artery lesions. Their ages ranged from 19 months to 12 years in the first study, 4 years to 15 years in the second study, and the male to female ratio was 8:5. In this study the interval between the first study and the second one was more than two years and six months. In the second study, progression of the CAL was noticed in 23% of the cases. It was unchanged in 54%, and regression was observed in 23%. Twenty-three percent of the patients were found to have an ejection fraction of less than 55%, and abnormal regional wall motion was found in 62% of the patients. Myocardial changes in the second endomyocardial biopsy were interstitial fibrosis in 62%, degeneration in 54%, disarray in 32% and inflammatory cell infiltration in 23%. One of the cases with Kawasaki disease, who had mild CAL, revealed massive inflammatory cell infiltration and myocytolysis in the second study performed seven years after onset, which suggested chronic myocarditis. Myocardial changes in the patients with advanced CAL were relatively mild, and low EF and abnormal regional wall motion were not always related to severity of CAL.(ABSTRACT TRUNCATED AT 250 WORDS)