Malignant Anomalous Aortic Origin of the Left Main Coronary Artery Managed by Ostial Reimplantation: A Case Report.

Anomalous origin of the left main coronary artery (LMCA) from the right coronary sinus with an interarterial course is a rare congenital variant associated with a high risk of myocardial ischemia and sudden cardiac death. We describe a 39-year-old man presenting with exertional chest pressure and dyspnea whose coronary CT angiography revealed an anomalous LMCA arising from the right sinus of Valsalva and coursing between the aorta and pulmonary artery without evidence of atherosclerosis. Transthoracic echocardiography was normal, and stress testing showed no inducible ischemia. The patient underwent surgical reimplantation of the anomalous LMCA into the left aortic sinus under cardiopulmonary bypass, with the right sinus defect closed using autologous pericardium. Recovery was uneventful, and postoperative imaging confirmed a widely patent LMCA. At three months, he remained asymptomatic with preserved ventricular function and no inducible ischemia. This case underscores the importance of high-resolution imaging for diagnosis and demonstrates that reimplantation offers a safe and effective surgical option for malignant coronary anomalies lacking an intramural segment.