Abstract
Multisystem inflammatory syndrome in adults (MIS-A) is a systemic inflammatory disease associated with COVID-19 and follows coronary artery aneurysms similar to Kawasaki disease. In many cases, it is improved by treatments such as high-dose steroids or intravenous immunoglobulin (IVIg). However, the role of untreated coronary artery aneurysms leading to future stenosis remains unknown. Untreated MIS-A may potentially lead to the formation of coronary aneurysms. In cases of COVID-19 where young adults present with angina-like symptoms, an evaluation for angina is considered. Herein, we report a case of a 27-year-old female who developed unstable angina with coronary artery aneurysms six months after COVID-19 infection. She required surgery for unstable angina, which resulted in an improvement in chest pain. Coronary artery lesions are considered to be related to MIS-A, and treatment was conducted in accordance with that for Kawasaki disease. Currently, the pathological differences and prognosis between MIS-A and Kawasaki disease remain unclear, but the elucidation of the conditions is warranted in the future.