A Giant Left Circumflex Coronary Artery Aneurysm

Key words: angina, computed tomography coronary angiography, coronary artery aneurysm, giant coronary aneurysm, pericardial tamponade, rupture, thrombosis

A 78-year-old man with chronic atrial fibrillation, diabetes mellitus, and prior coronary artery bypass grafting (CABG) was admitted for coronary angiography due to severe aortic valve stenosis. A known coronary artery aneurysm (CAA) in the obtuse marginal (OM) branch was an incidental finding on a coronary angiography performed 10 years ago, just prior to the CABG operation (Figure 1A).

The current coronary angiography depicted a giant CAA of the OM as a result of progressive size growth during this 11-year period (Figure 1B; Video 1). On computed tomography coronary angiography (CTCA), the CAA measured 63 mm in diameter and contained intraluminal thrombus (Figure 2A). The patient was referred for aortic valve replacement and aneurysm resection; however, the aneurysm was deemed to be non-resectable due to severe calcification, thus posing a high operative risk. The patient eventually underwent transcatheter aortic valve implantation.

CAAs are defined as a dilated segment of the coronary artery, the diameter of which exceeds that of the adjacent coronary portion by more than 1.5 times. A diameter >20 mm defines a giant CAA. Despite being present in up to 4.9%, while giant CAAs occur only in 0.02% of patients undergoing coronary angiography, their etiology is not yet clear with advanced atherosclerosis considered the most common cause. To our knowledge, the current case is the largest giant CAA reported in the literature.