Which of the following is the most dreaded complication of Kawasaki's disease?

Kawasaki disease is an acute febrile, usually self-limited illness of infancy and childhood (80% of patients are 4years old or younger); it is associated with an aeritis affecting large to medium-sized, and even small vessels. Its clinical significance stems primarily from a predilection for coronary aery involvement that can cause aneurysms that rupture or thrombose, resulting in acute myocardial infarctions.