Abstract 12499: Anomalous Coronary Arteries Are Associated With Ischemia in the Ischemia Trial

Introduction: Coronary anomalies are detected in 0.3-2.3% of patients undergoing coronary computed tomography angiography (CCTA). Data are scarce on atherosclerosis severity in anomalous arteries and relationship to ischemia on stress testing. Hypothesis: High risk features of anomalous coronary arteries are associated with ischemia, even in the absence of coronary stenosis on CCTA. Methods: 5,903 participants enrolled in the ISCHEMIA trial program with site-determined moderate or severe ischemia underwent CCTA. A core laboratory assessed atherosclerosis severity and made note of anomalous coronary origin. A single reader at the CCTA core laboratory re-evaluated all identified anomalies to assess high risk features and origin, blinded to stress test results. Patients were excluded if stress test results were unavailable. We assessed the relationship between type of anomaly and vessel with ischemia in the subtended territory on stress imaging, and stenosis severity. Results: There was anomalous origin of a coronary artery in 56 of 5,903 CCTA cases (0.9%). Age, sex and CAD risk factors were similar between patients with vs. without anomalies. Anomalous origin affected the left circumflex (LCX) in 28, right coronary artery (RCA) in 21, left main (LM) in 4, and left anterior descending (LAD) in 3. Ischemia was severe on stress testing in 58.2%, moderate in 34.5%, mild in 3.6% and absent in 3.6%. High risk anomalies were present in 17/56 (30.3%, 16/21 RCA and 1/4 LM), including inter-arterial course in 28.6%, intra-mural course in 1.8%, and slit-like orifice in 12.5%. Most anomalous coronaries (82.9%) were associated with ischemia in the subtended territory. Among anomalies associated with ischemia, 37.9% had <50% stenosis and 62.1% had <70% stenosis (Figure). Of those with <70% stenosis, 27.6% had high risk features. Conclusions: Anomalous coronary arteries in stable patients are associated with ischemia, even in the absence of severe atherosclerotic disease.