Abstract

Giant coronary artery aneurysm (CAAs) are unusual with reported incidence rate of 0.02% of patients who undergo cardiac surgery; often the proximal right coronary artery (RCA) is involved. They are defined as a localized area of dilatation exceeding 2cm in diameter. We report a case of an incidentally diagnosed partially thrombosed right CAA. A 69 years-old-male, with history of possible Marfan´s Syndrome and previously negative genetic study, was referred to the Cardiovascular Magnetic Resonance Unit for an outpatient assessment of his aortic dimensions. He had history of cardiac surgery with valve-sparing aortic root replacement, 15 years ago. Additionally, he had strong family history of sudden death probably related to acute aortic syndromes. The patient was asymptomatic, but interestingly during his most recent outpatient clinic appointment he reported an episode of chest pain 5 months before for which he called an ambulance but as the ECG only showed bradycardia, he was not taken to the hospital. Physical examination and routine blood test were irrelevant. The CMR study of the thoracic aorta showed an incidental aneurysmal dilatation of the proximal/mid RCA (diameter:40mm and length:60mm, Figure1:A). It was partially filled with a parietal thrombus. Biventricular ejection fraction was normal. CT angiogram confirmed the CMR findings (Figure1:B-C) and also showed ectatic LAD and distal RCA arteries. Myocardial stress perfusion scintigraphy exposed partial thickness infarction of the inferior and inferoseptal walls with a scar burden of 15% with additional mild superimposed ischaemia accounting to less than 5% of the myocardium. Coronary angiogram was then performed and due the complexity of the lesion and the high risk of embolization of thrombotic material in a patient with normal ejection fraction, the overall consensus was to treat him medically with anticoagulation, beta-blockers, ARE inhibitors and statins. CAAs are rare, occurring in 0.3% to 4.9% of patients undergoing coronary angiograms, while giant coronary artery aneurysms are even rarer. They are most commonly associated with male gender and hyperlipidemias. Atherosclerosis remains the most common cause of CAAs although they are also associated with congenital malformations, Kawasaki disease, autoimmune diseases (polyarteritis nodosa, lupus erythematosus and scleroderma), trauma, coronary artery dissection, rheumatic heart disease, mycotic coronary emboli, and syphilis, among others. In our case, comprehensive multimodality imaging led to the definitive diagnosis. Untreated CAAs may be complicated by ischaemia, myocardial infarction, distal embolization due to thrombus formation within the aneurysm, calcification, fistula formation and spontaneous rupture. Various surgical approaches to treat giant CAAs are reported in the literature, such us, excision of the aneurysm with bypass to the distal coronary artery. However, percutaneous intervention could be possible in some cases. Abstract P259 Figure 1.