Coronary artery fistulas: a systematic review and pooled analysis of anatomy, risk stratification and contemporary management

OBJECTIVE: Coronary artery fistulas (CAFs) are rare congenital or acquired anomalies characterised by abnormal coronary communications, with variable natural history and no consensus on optimal management. METHODS: A comprehensive state-of-the-art review and pooled analysis of published literature was conducted, integrating clinical, anatomical, imaging, management and outcome data from 1966 patients with 1986 CAFs. Comparative descriptive analyses between complicated and uncomplicated cases were performed to identify recurring features associated with adverse clinical outcomes. RESULTS: Specific anatomical and clinical patterns were more frequently observed in patients with complications, including fistulas originating from the right coronary artery or left main coronary artery, drainage into venous or left-sided structures, large-calibre fistulas and reduced ventricular function. Based on these recurring patterns, two pragmatic phenotypes of CAFs (higher-risk and lower-risk) were identified. Given the descriptive nature of the available evidence and the absence of formal multivariable modelling, these findings should be considered hypothesis-generating rather than indicative of independent predictors. CONCLUSIONS: CAFs are heterogeneous vascular anomalies with variable clinical presentation and substantial potential for complications. An integrated assessment of anatomical configuration, fistula size, drainage pattern and ventricular function may support structured clinical evaluation and individualised management. We propose a practical anatomy- and risk-informed framework to guide multidisciplinary decision-making and follow-up strategies.