Predictive value of CT-FFR in right anomalous aortic origin of coronary artery in an adult population

Background/Introduction Right anomalous aortic origin of a coronary artery (R-AAOCA) is a rare congenital anomaly potentially associated with adverse events. The growing use of coronary computed tomography angiography (CCTA) in adult patients with suspected coronary artery disease (CAD) has led to increased detection of AAOCA and a noninvasive tool to predict cardiovascular outcomes in AAOCA is needed. Purpose To assess the prognostic value of CCTA-derived fractional flow reserve (CT-FFR) in an adult population with R-AAOCA. Methods In this study, consecutive patients with R-AAOCA from two registries were included between 06/1999 and 06/2025. All participants underwent CT-FFR analysis using cFFR software alongside additional CCTA-based quantification of CAD and anatomical features. Major adverse cardiac events (MACE) were defined as death of all cause, (survived) sudden cardiac death, myocardial infarction and urgent/non-urgent revascularization of the proximal anomalous course. AAOCA-related revascularization at baseline was censored and excluded from the outcome analysis. Follow-up assessments were conducted through telephone interviews and clinical reports. Results A total of 180 patients (28% female; mean age 55±13 years) were included in the final analysis. Of these, 38 patients (21%) underwent AAOCA-related revascularization. After a median follow-up of 33 months (IQR 9-54months), 16 patients (9%, thereof 63% with previous AAOCA-related revascularization) experienced a first MACE, including 8 deaths (1 cardiovascular death, 3 non-cardiovascular deaths and 4 unknown), 1 myocardial infarction, and 7 non-urgent revascularizations. CT-FFR emerged as a significant predictor (odds ratio (OR) 0.011, 95%-CI 0.000-0.257, p=0.005), but this association lost significance after adjusting for CAD within the anomalous vessel (OR 0.046; p=0.072). OR for presence of CAD within the anomalous vessel was 4.508 (95%-CI 1.547-13.136, p=0.006). Length of the intramural course was the only anatomical feature, which could independently predict MACE (OR 1.110, 95%-CI 1.006-1.224, p=0.038). Kaplan-Meier analysis demonstrated a significant difference in event-free survival based on the length of the intramural course and the presence of CAD in the anomalous vessel, but not for CT-FFR. Conclusions In adult patients with R-AAOCA, length of the intramural course and CAD in the anomalous vessel, but not CT-FFR, was predictive of adverse outcomes, highlighting the value of the anatomical high-risk feature intramural course as well as the prognostic relevance of atherosclerosis in this population.