Malignant Course of the Right Coronary Artery Originating from the Left Main Coronary Artery: An Odd Exit

Introduction: Congenital coronary artery anomalies are quite uncommon with estimates ranging from 0.2% to 1.3% on coronary angiography. The rarity of these anomalies makes their diagnosis a formidable challenge. Variable arterial courses have been described. In this report, we present a case with unique arterial course, which starts as a hyperacute take-off of the right coronary artery (RCA) from the left main coronary artery (LMCA), with subsequent coursing, without external compression, between the right ventricular outflow tract and aorta. Our case is relevant to the concept of whether we should keep a reasonable index of suspicion for coronary artery anomalies during cardiac evaluations of patients undergoing non-cardiac surgeries. Clinical case: This is an asymptomatic 47-year-old African American female who presented for cardiac clearance for renal transplantation. She had a past medical history of hypertension, bronchial asthma, and former smoking of 10 years (quitting 15 years prior to presentation). She also has end-stage renal disease on hemodialysis. Cardiac workup revealed left ventricular hypertrophy on EKG, multi-chamber dilation seen on echo, and anomalous RCA course seen on CT coronary angiography. Cardiac catheterization revealed non-obstructive coronary artery disease of the LCX and RCA. After consulting with cardiothoracic surgery, conservative medical management was decided based on the patient’s risk stratification. She was advised to have close monitoring of her condition. Discussion: Coronary artery anomalies represent the second most common cause of sudden cardiac death in young athletes. At this time, the prevalence of right coronary artery (RCA) take off from the left coronary sinus occurs at a percentage of 0.019% to 0.49%. The RCA origination from the left main coronary artery (LMCA) accounts for only 0.65% of these anomalies. Our patient had high-risk anatomy consisting of a hyper-angulated take-off of the RCA from the LMCA as well as course between the pulmonary artery and right ventricular outflow tract (RVOT). CT coronary angiography is the most useful imaging modality that characterizes coronary artery anomalies. Although this patient exhibited no signs or symptoms of cardiorespiratory compromise, she warranted a full cardiac workup preoperatively that incidentally revealed a coronary anomaly. Recognition of this disease is critical for timely prevention of potential complications as well as discussion of goals of care. Guidelines for medical versus surgical management are available, but the management strategy should be individualized, with the highest consideration given to risk-benefit analysis.