Anomalous Right Coronary Artery with Interarterial Course: Gaps in Clinical Management

Abstract Anomalous origin of the right coronary artery from the opposite sinus with an interarterial course (RCA-ACAOS with IAC) is an increasingly recognized incidental finding on coronary computed tomography angiography (CCTA). However, standardized management protocols are lacking, and the real-world approach to these patients remains poorly characterized. This retrospective, single-center, observational study included all consecutive patients diagnosed with coronary artery anomalies by CCTA between April 2019 and April 2024. Baseline characteristics, anatomical high-risk features, management patterns, and clinical outcomes over a mean 37.3-month follow-up were analyzed. Among 4,560 patients who underwent CCTA, 27 (0.59%) had a coronary anomaly, with 15 (0.32%) having RCA-ACAOS with IAC. This group exhibited a higher prevalence of high-risk anatomical features like slit-like orifices (33.3% vs. 0%, p = 0.065) compared to other anomalies. The composite cardiac event rate was 22.2%, driven exclusively by unplanned coronary angiograms performed for suspected acute coronary syndrome, none of which identified a culprit lesion. While event rates were higher in the RCA-ACAOS with IAC group (26.7% vs. 16.7%), the difference was not statistically significant (p = 0.357). Notably, functional stress testing was underutilized, with only 20% of RCA-ACAOS with IAC patients undergoing evaluation for inducible ischemia. RCA-ACAOS with IAC is generally associated with favorable outcomes and low event rates. Moving from a purely anatomical to a functionally guided management paradigm may improve patient care in this patient population.