A case report of successful primary percutaneous coronary intervention to an occluded anomalous left main coronary artery arising from the right coronary sinus.

Background: Anomalous aortic origin of a coronary artery from the opposite sinus is a rare congenital abnormality that may be encountered during primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI).

Case Summary: A 65-year-old man presented with chest pain and signs of heart failure. Electrocardiogram demonstrated atrial fibrillation with ST elevation in the high lateral leads, and he was taken emergently to the cardiac catheterization laboratory for primary PCI. Coronary angiography identified the culprit to be an occluded anomalous left main coronary artery (LMCA) arising from the right coronary cusp, and primary PCI was successfully performed in the LMCA and the left anterior descending artery (LAD). Computed tomography angiography confirmed a benign retroaortic course of the anomalous LMCA with no additional high-risk features, as well as a new left atrial appendage thrombus. He subsequently developed deep venous thrombosis, acute pulmonary embolism, and acute kidney injury secondary to renal artery embolism with associated infarction. Workup for patent foramen ovale and thrombophilia were negative, and he was discharged in a stable condition. At 2-month follow-up, he was asymptomatic with no evidence of myocardial ischaemia on stress cardiac magnetic resonance imaging.

Discussion: We present the first reported case of an occluded anomalous LMCA arising from the right coronary sinus in a patient presenting with STEMI. Rapid recognition of this congenital anomaly and selection of an appropriate guide catheter were keys to achieving timely reperfusion and a good outcome in this case.