Coronary Computed Tomography Angiography Identifying a Single Coronary Artery With a Critical Left-Main-Equivalent Stenosis Treated by Elective PCI.

Single coronary artery (SCA) is a rare congenital anomaly in which the entire myocardium is supplied by a single coronary ostium, and clinical significance depends largely on the anatomical course and presence of concomitant atherosclerotic disease. We report the case of a 58-year-old man presenting with exertional chest pain whose coronary computed tomography angiography revealed an SCA arising from the right coronary sinus with a critical 98% stenosis in the left main equivalent trunk supplying both the left anterior descending and circumflex territories. Although coronary artery bypass grafting was advised due to the high-risk anatomy, the patient declined surgical revascularization. Elective percutaneous coronary intervention was performed using a 7 F JR guiding catheter, sequential predilatation, and implantation of appropriately sized drug-eluting stents, resulting in full restoration of TIMI 3 flow without complications. This case underscores the value of modern coronary CT angiography in the detailed assessment of coronary anomalies and demonstrates that, in carefully selected patients who refuse or are unsuitable for surgery, percutaneous intervention can be a safe and effective alternative even in the setting of a left-main-equivalent lesion within a single-origin coronary system.