168 Prevalence and adverse cardiac events in anomalous aortic origin of coronary artery (AAOCA) in ct coronary angiography in west of Scotland

Background Anomalous aortic origin of a coronary artery (AAOCA) is a congenital abnormality of the origin or course of coronary artery. The clinical manifestations of coronary artery anomalies vary in severity based on its course. It is reported as a leading cause of sudden cardiac death in young athletes. Computed tomography Coronary Angiography (CTCA) is an imaging modality of choice for identification and characterization of coronary artery anomalies. The prevalence of AAOCA is usually cited as 1%–2% of the general population and also reported at 0.8%–1.3% in invasive angiographic studies and 1%–5% in reported CTCA series. CTCA service is established in West of Scotland since 2015 and no data has been published about prevalence of AAOCA nor any directly related adverse cardiac events formally studied in these patients here. Methods Patients with anomalous aortic origin of coronary artery (AAOCA) were identified in the CTCA series between February 2015 and October 2020 in a large tertiary referral centre that caters to most CTCA referrals in West of Scotland. The electronic medical records of these patients were retrospectively checked between February 2015 and February 2021 with a standard evaluation questionnaire and data was independently reviewed by the authors. Results A total of 2840 patients’ electronic records were evaluated and 79 patients with AAOCA were identified. There were 57 males (72%) and 22 Females (28%). The mean age was 47.4 years for males and 51.3 years for females. Out of 79 AAOCA, 59% were anomalous right coronary artery, 29% were anomalous left circumflex, 7% were anomalous left main coronary artery and 2% were anomalous Left anterior descending coronary artery. 86% were referred for symptom of chest pain (deemed atypical in 94% of these patients with further evidence of negative or inconclusive ETT), 6% had arrhythmia (no sudden cardiac death or ventricular arrhythmias were recorded), unexplained dyspnoea in 4%, Transient Loss of consciousness (no CPR needed for recovery) in 4% of patients. High risk (intra-mural, intra-myocardial, high origin or inter-arterial course) of AAOCA was noted in 47% patients (n=37; 84% originated from a different coronary sinus and 16% directly from another coronary artery). Obstructive coronary disease (CAD-RADS score = 3 and above) was noted in only 9% of AAOCA (n=7) compared to 29% (n=23) in non-anomalous coronary arteries. All AAOCA with obstructive disease were noted to be further referred for functional assessment of ischaemia or invasive coronary angiography. Only 14% (n=5 out of 37) with a high risk AAOCA course were referred by the clinicians for functional assessment of ischaemia or arrhythmia and the results were benign. There were 4 deaths noted in this observed cohort and none of them were directly related to coronary artery disease. Conclusions The observed prevalence of AAOCA in this CTCA series is 2.8% in West of Scotland and noted to be higher in males (p Conflict of Interest None