Stent-free strategy for STEMI in a retroaortic anomalous left circumflex artery: addressing elliptical vessel geometry and perioperative bleeding risk: a case report.

Background: An anomalous left circumflex artery (LCx) arising from the right coronary sinus typically follows a retroaortic course and is considered benign regarding sudden cardiac death. However, it remains susceptible to atherosclerosis, where its unique vessel geometry may significantly influence percutaneous coronary intervention (PCI) strategies. Case summary: A 70-year-old man with multiple risk factors and sub-obstructive rectal cancer awaiting surgery presented with inferior ST-segment elevation myocardial infarction (STEMI). Coronary angiography showed the absence of the LCx from the left coronary artery and no significant right coronary artery (RCA) stenosis. Intravascular ultrasound (IVUS) of the left main trunk confirmed the absence of a left-sided LCx ostium. Subsequent engagement of the right coronary sinus revealed a separate ostium caudad to the RCA, consistent with a retroaortic LCx. IVUS of the culprit lesion demonstrated a lipid-rich plaque with persistent elliptical vessel morphology. Following optimal lesion preparation, a drug-coated balloon (DCB) was deployed to address the atypical geometry and facilitate semi-emergent surgery. Laparoscopic rectal resection was successfully performed 6 weeks post-PCI. Six-month Computed tomography coronary angiography confirmed sustained patency, and the patient remained event-free over a 2-year follow-up. Discussion: Retroaortic anomalous LCx can mimic RCA occlusion in STEMI. In such cases, persistent non-circular vessel geometry may favour a stent-free, geometry-guided strategy as a rational individualized option, especially when early surgery is required.