Prevalence and characteristics of coronary anomalies in Bulgarian patients undergoing coronary angiography

BACKGROUND: Coronary artery anomalies (CAAs) are rare congenital abnormalities with variable reported prevalence. Data from Eastern Europe remain limited. This study assessed the prevalence and characteristics of CAAs in a large Bulgarian angiographic cohort. METHODS: We retrospectively analyzed 9 567 consecutive patients who underwent diagnostic coronary angiography between January 2014 and July 2025 at a single tertiary center. CAAs were classified according to the Angelini system into anomalies of origin and course, intrinsic anomalies and anomalies of termination. Prevalence was calculated both including and excluding myocardial bridges and commonly considered benign anatomical variants. RESULTS: Overall, 530 anomalies were identified (5.5%), including 396 myocardial bridges (4.1%). After exclusion of myocardial bridges and anatomical variants, 83 patients had true CAAs (0.87%). Anomalies of origin and course predominated (63.9%), most commonly involving anomalous origin of the left circumflex artery from the right coronary sinus or right coronary artery (0.32% of the population). Coronary fistulae accounted for 36.1% of anomalies (0.31%). High-risk, Rigatelli class III anomalies were uncommon (9.6%). CONCLUSION: The prevalence and distribution of CAAs in this Bulgarian cohort are consistent with international data. As shown in previous studies, the reported prevalence was strongly influenced by the classification system applied and by the inclusion or exclusion of myocardial bridges and selected anatomical variants, underscoring the need for standardized definitions in future research.