Coronary Artery Bypass Grafting in a Patient with Anomalous Left Coronary System Arising from the Right Coronary Cusp

Anomalous coronary origin from the opposite sinus is a rare congenital coronary anomaly with variable anatomical patterns and clinical significance depending on vessel course and associated coronary artery disease. A 53-year-old hypertensive male presented with exertional angina (Canadian Cardiovascular Society (CCS) Class II). He had a prior history of NSTEMI managed conservatively. Echocardiography revealed mild left ventricular dysfunction (Left Ventricular Ejection Fraction (LVEF) ~45%) with regional wall motion abnormalities. Coronary angiography demonstrated anomalous coronary origins arising from the right coronary cusp. Computed tomography (CT) coronary angiography demonstrated closely adjacent coronary origins arising from the right coronary cusp, including the native right coronary artery and an anomalous left coronary system with subsequent branching into the left anterior descending artery, ramus intermedius, and left circumflex artery. Three-dimensional CT reconstructions further clarified the complex coronary anatomy. Such anatomical configurations are rarely reported in patients undergoing coronary artery bypass grafting (CABG). Significant multivessel atherosclerotic disease was present (SYNTAX score 34). The patient underwent successful on-pump CABG. This case highlights the coexistence of a rare congenital coronary anomaly with severe atherosclerotic disease requiring surgical revascularization. Careful anatomical delineation using CT coronary angiography (CTCA) is essential for safe surgical planning.