Physiological Evaluation of Anomalous Aortic Origin of a Coronary Artery Using Computed Tomography–Derived Fractional Flow Reserve

BACKGROUND: With the emergence of coronary computed tomography (CT) angiography, anomalous aortic origin of a coronary artery (ANOCOR) is more frequently diagnosed. Fractional flow reserve derived from CT (FFRCT) is a noninvasive functional test providing anatomical and functional evaluation of the overall coronary tree. These unique features of anatomical and functional evaluation derived from CT could help for the management of patients with ANOCOR. We aimed to retrospectively evaluate the physiological and clinical impact of FFRCT analysis in the ANOCOR registry population. METHODS AND RESULTS: The ANOCOR registry included patients with ANOCOR detected during invasive coronary angiography or coronary CT angiography between January 2010 and January 2013, with a planned 5‐year follow‐up. We retrospectively performed FFRCT analysis in patients with coronary CT angiography of adequate quality. Follow‐up was performed with a clinical composite end point (cardiac death, myocardial infarction, and unplanned revascularization). We obtained successful FFRCT analyses and 5‐year clinical follow‐up in 54 patients (average age, 60±13 years). Thirty‐eight (70%) patients had conservative treatment, and 16 (30%) patients had coronary revascularization after coronary CT angiography. The presence of an ANOCOR course was associated with a moderate reduction of FFRCT value from 1.0 at the ostium to 0.90±0.10 downstream the ectopic course and 0.82±0.11 distally. No significant difference in FFRCT values was identified between at‐risk and not at‐risk ANOCOR. After a 5‐year follow‐up, only one unplanned percutaneous revascularization was reported. CONCLUSIONS: The presence of ANOCOR was associated with a moderate hemodynamic decrease of FFRCT values and associated with a low risk of cardiovascular events after a 5‐year follow‐up in this middle‐aged population.