55 - PATHOLOGICAL FEATURES OF CORONARY ARTERITIS SEQUALAE IN ADULTS WITH A HISTORY OF KAWASAKI DISEASE

【Background】Cases of sudden death in young adults with a history of KD have been reported, drawing attention to the association between the sequelae of coronary arteritis and the progression to atherosclerosis. We performed a pathological study of coronary artery lesions (CALs) in young adults with a history of KD. 【Methods】The study included 12 adults with a history of KD who died suddenly and underwent autopsy (age 18-50 years; 10 males, 2 females). The subjects were categorized into two groups: those with autopsy-confirmed coronary artery aneurysms (CAAs) (Group A, n=6) and those without such aneurysms (Group B, n=6). We assessed BMI, coronary risk factors, coronary pathology, and cause of death (COD) for each group. 【Results】In Group A, persistent coronary artery aneurysms were observed in six branches, and recanalized aneurysms were found in three branches. In cases of persistent aneurysmal dilation, fresh thrombotic occlusion was observed exclusively in one branch, while recanalization was observed at the distal side of the aneurysm in the remaining cases. Atherosclerotic changes in the aneurysm were observed in two cases: eccentric atheromatous plaques were formed in the fibrous thickened intima as a vasculitis scar. In one case (a 34-year-old male), a ruptured atheromatous plaque was formed in the regressed aneurysm. The COD in Group A was acute myocardial infarction in four cases. In the other two cases, arrhythmia was strongly suspected as the COD. In Group B, there was no evidence of vasculitis scars in the coronary arteries. Among the four cases with a BMI of 25 or higher, atheromatous plaque was observed in the proximal portion of the left anterior descending artery (LAD). In one case, acute coronary occlusion occurred due to plaque erosion. In the other five cases, the causes of death were unrelated to CALs and involved chronic malnutrition, dehydration, and other factors.【Discussion】In cases where CAAs were formed during the acute phase, continuous follow-up should be performed even after the aneurysm has regressed. On the other hand, in cases where CAAs were not formed during the acute phase, preventive measures for lifestyle-related diseases are crucial, similar to non-KD cases. However, this study did not include cases in which CAAs were not formed but vasculitis sequelae occurred. Further investigation is needed.