Prevalence and CT angiographic evaluation of coronary artery anomalies in 20,243 consecutive patients: a retrospective study

BACKGROUND: Coronary artery anomalies (CAAs) are rare congenital abnormalities involving the origin, course, or structure of coronary arteries. While often incidental, some variants have clinical and procedural implications. With the increasing use of computed tomography coronary angiography (CTCA), more anomalies are being detected, yet large-scale data from India remain limited. OBJECTIVES: To evaluate the prevalence, anatomical patterns, and clinical relevance of CAAs over a 12-year period using CTCA at a high-volume tertiary cardiac center in India. METHODS: In this retrospective study, 20,243 consecutive patients undergoing multidetector CTCA between January 2011 and October 2023 were analyzed. Coronary anomalies were categorized into myocardial bridging (MB) and non-MB types based on Angelini's classification. Each scan was independently reviewed by both a radiologist and a cardiologist. RESULTS: Coronary artery anomalies (CAAs) were identified in 1513 patients (overall prevalence 7.5%), largely driven by myocardial bridging (MB). When MB was excluded, the prevalence of non-bridging anomalies was 0.9% (n = 183), including both isolated and combined cases. Isolated myocardial bridging was the most common finding, identified in 1330 patients (87.9%), predominantly involving the mid-segment of the left anterior descending artery. Isolated non-bridging anomalies were observed in 171 patients, while 12 patients had combined MB and non-MB anomalies. Among non-bridging anomalies, the most frequent included anomalous right coronary artery origin from the left sinus with an interarterial course (26.9%), retroaortic left circumflex artery (9.9%), separate origins of the LAD and LCX (8.8%), and high take-off anomalies (7.6%). Most anomalies were classified according to Angelini's framework, with a small subset remaining unclassified due to atypical anatomical presentations. CONCLUSIONS: This 12-year retrospective cross-sectional study represents one of the largest single-center CTCA-based datasets on coronary artery anomalies (CAAs) globally. The findings highlight the utility of CTCA in detecting and characterizing both benign and potentially significant anomalies. The anatomical insights derived from this cohort have direct clinical relevance, aiding interventional cardiologists in procedural planning and risk stratification. Future multicenter studies are warranted to further refine diagnostic algorithms and management strategies across diverse populations.