Context: Coronary artery aneurysm is an uncommon condition that can be a cause of death when it thromboses or ruptures. It is always associated with destruction of the tunica media, usually associated with atherosclerosis, and commonly associated with chronic inflammation.
Objective: To review the pathology, epidemiologic and clinical features, and pathophysiology of coronary artery aneurysm, particularly new research results, drawing out implications for the understanding, diagnosis, and treatment of this condition.
Data sources: Pertinent literature and illustrative cases at our institution.
Conclusions: Inflammation spilling over into the tunica media from the tunica intima may link atherosclerosis to aneurysm formation, but vasculitis without atherosclerosis causes coronary artery aneurysms in young children with Kawasaki disease. Increased proteolysis of extracellular matrix proteins is probably one mechanism of coronary artery aneurysm formation, either due to overactive matrix metalloproteinases or underactive inhibition of these proteinases, and an excess of transforming growth factor beta may be another mechanism in the pathogenesis. Coronary atherosclerosis is a universal disease of adults, but only 1.5% of them have coronary aneurysms; this small group may be those with a second coronary artery disease, such as vasculitis.