Abstract
Kawasaki disease (KD) is an acute systemic vasculitis that preferentially involves coronary arteries in young children, and predominantly affects young children. Cardiovascular lesions are the most severe complications of this disease. Even though giant aneurysms are rare, they can complicate thrombus formation, leading to myocardial ischemia, myocardial infarction, and even cardiac death. Later in life, it can lead to steno-occlusive lesions. Follow-up led to coronary artery stenosis. In this article, we report a case of a pediatric patient with KD who presented with a large thrombus within a giant coronary aneurysm as a consequence of delayed treatment with intravenous immunoglobulin (IVIG) and IVIG resistance, which contributed to the formation of coronary artery lesions. Transthoracic echocardiography is a valuable tool for detecting coronary artery abnormalities; however, computed tomography coronary angiography is valuable for precisely delineating coronary anatomy and complications. It is important to maintain a slightly higher international normalized ratio to decrease the risk of thrombosis in coronary artery aneurysms.