Abstract 15578: A Rare Case of Anomalous Left Main Coronary Artery Origin Presenting as ST Elevation Myocardial Infarction

Abstract

Background: ST-segment elevation myocardial infarctions (STEMI) are uncommon presentations of coronary artery anomalies and pose challenges in the emergent setting of percutaneous coronary interventions. We describe an extremely rare case of left main coronary artery (LMCA) originating off the right coronary artery (RCA) in a patient who presents with STEMI and was found to have Medina 1,1,1 lesion at the origin of the anomalous (LMCA). Case Presentation: An 81-year old male, with a past medical history significant for aortic stenosis and hyperlipidemia, presents to the emergency room for substernal non-radiating chest pressure. His electrocardiogram showed ST segment elevations in inferior and anterior leads. He was taken emergently to the cardiac cath lab. Coronary angiogram revealed a single right coronary ostium with an anomalous LMCA to mid left anterior descending (LAD) artery via dual insertion within a myocardial bridge. There was severe 90% Medina 1,1,1 bifurcating proximal RCA stenosis and 90% proximal LMCA stenosis. The entire left coronary system was fed by the anomalous LMCA, which was inserted into the mid-LAD in a dual insertion, between which there was a myocardial bridge. Cardiothoracic surgery team was consulted, and decision was made to pursue coronary artery bypass grafting (CABG). An intra-aortic balloon pump was placed via right femoral artery and patient was taken for emergent surgery, where he underwent 3 vessel CABG (left internal mammary artery to LAD, saphenous venous graft to obtuse marginal branch and posterior descending artery). Discussion: A broad spectrum of coronary anomalies have been reported, but their incidence in STEMI is rare. We discuss a very rare anomaly in which the entire left coronary system branches off the RCA, and culprit lesion was found to be a Medina 1,1,1 lesion. We aim to add to the sparce data pool of STEMI management in patients with anomalous coronary arteries.