Prevalence and clinical significance of coronary arteries variations: A systematic review with meta-analysis

BACKGROUND: This systematic review and meta-analysis aimed to determine the prevalence and clinical relevance of main coronary artery (CA) origin and course anomalies (class A variations) in healthy populations. METHODS: This systematic review and meta-analysis followed PRISMA 2020 and Evidence-based Anatomy guidelines. A literature search was conducted across PubMed, Google Scholar, Scopus, and Web of Science. Statistical analysis was performed in R using random-effects models, with pooled prevalence calculated via the Freeman-Tukey transformation. Subgroup, meta-regression and leave-one-out analyses was performed to explain the source of heterogeneity. RESULTS: A total of 58 studies with 503,171 subjects were included. The pooled prevalence of typical CA anatomy was 97.89% (95% CI: 97.51-98.25), while main CA anomalies had a prevalence of 2.11% (95% CI: 1.82-2.70). Subgroup analysis retrieved statistically significant differences for nationality and study type, and meta-regression revealed increasing trend of CA variants with later publication years. The most common variation was anomalous origin of the right coronary artery from the left sinus (0.30%), followed by high take-off right coronary artery (0.14%). Left coronary artery anomalies were less frequent, with anomalous origin from the right sinus recorded in 0.05% of cases. Subgroup analyses revealed higher prevalence in American populations and computed tomography-based studies. CONCLUSIONS: Main CA anomalies (class A variations) are rare but clinically significant due to their association with ischemic events and sudden cardiac death, particularly variants with interarterial or intramural courses. Early identification through modern imaging is critical for risk stratification and clinical decision-making.