Abstract Body (Do not enter title and authors here): Background:
Coronary artery aneurysm seen in patients undergoing coronary angiography is an uncommon disorder with poorly understood pathophysiology. Patients have variable clinical presentations and often poor long-term outcomes. Management of these patients still pose a clinical dilemma given there are no standardized treatment guidelines

Description of case and discussion
A 44-year-old male with a significant past medical history of hypertension, diabetes mellitus, and hyperlipidemia presented in the emergency room (ER) for acute onset chest pain. His pain was retro-sternal, non-radiating, and pressure-like in nature. Pain was initially rated as 2/10 intensity which progressed to 9/10 later in the day with associated diaphoresis. He took acetaminophen which provided no relief. His electrocardiogram (EKG) showed ST elevation in the inferior and lateral leads. Initial troponin was negative. The cardiac catheterization laboratory was activated and the patient was administered loading doses of Aspirin, ticagrelor and a bolus of intravenous (IV) heparin.
An emergent left heart catheterization and coronary angiogram was performed which revealed a 100% thrombotic occlusion of the mid LAD as well as severe ectasia of the proximal vessel. There was mild ectasia of the left circumflex and right coronary arteries without any significant stenosis. There were no collaterals to the distal LAD consistent with an acute presentation. At the level of the occlusion (mid LAD), there was an aneurysm measuring up to 10 mm in diameter by angiography. Intravenous eptifibatide was administered with the continuation of IV heparin. The thrombotic occlusion was managed medically with a plan to repeat angiography in 24-48 hours. Transthoracic echocardiography revealed a preserved left ejection fraction at about 55-60% with mild hypokinesis of the apex. Repeated angiography in 48 hours revealed a mostly patent LAD with diffuse TIMI 2 flow and sub occluded distal LAD at the apex. He was discharged home with dual antiplatelet therapy, a statin, and a beta blocker. Two weeks later he was seen on outpatient setting and his medications were transitioned to Rivaroxaban and clopidogrel

Conclusion:
Large LAD aneurysms are not common and they carry long term complications which includes thrombosis (as seen in our patient), fistula formation, and rupture. Management of this condition is still challenging as there are no standardized management guidelines.