Anomalous Aortic Origin of the Right Coronary Artery: Invasive Haemodynamic Assessment in Adult Patients With High-Risk Anatomic Features.

Background: Anomalous aortic origin of a right coronary artery (AAORCA) with an interarterial course merits further evaluation; however, robust risk assessment strategies for myocardial ischemia and sudden cardiac death are currently lacking. The aim of this study is to explore the potential role of fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), and intravascular ultrasound (IVUS) in patients with AAORCA. Methods: Consecutive adult patients with AAORCA with an interarterial course were included. Computed tomography angiography, noninvasive ischemia detection, and FFR, iFR, and IVUS were performed at baseline and during adrenaline-induced stress. External compression was evaluated with IVUS. Results: Eight patients (63% female, mean age: 53 ± 9.5 years) were included. Five patients (63%) were symptomatic, and computed tomography angiography revealed high-risk anatomy of the AAORCA in all patients. Only in 1 (12.5%) patient FFR and iFR were positive; however, this was attributed at large to concomitant diffuse atherosclerosis. In 2 of 8 (25%), IVUS revealed external compression; however, the ostial coronary surface area remained unchanged. In all patients, a conservative treatment strategy was pursued. During a mean follow-up of 29.3 months (standard deviation ±2.6 months), symptoms spontaneously disappeared in 4 of 5 (80%) and no adverse cardiac events occurred in any of the patients. Conclusions: Despite the presence of high-risk anatomy in all patients, none had proven ischemia prompting a conservative treatment strategy. No adverse cardiac events occurred during follow-up, and in the majority of patients, symptoms spontaneously disappeared. Therefore, FFR, iFR, and IVUS with pharmacologic stress merit further investigation and might contribute to ischemia-based risk stratification and management strategies in adult patients with AAORCA.