Treatment Strategies for Coronary Artery Fistulas: A Contemporary Review of Anatomy, Diagnosis, and Management

Coronary artery fistulas (CAFs) are rare but clinically important congenital or acquired anomalies characterized by abnormal vascular connections between one or more coronary arteries and cardiac chambers or great vessels. Although these fistulas, which bypass the myocardial capillary bed, are often asymptomatic and detected incidentally, large or aneurysmal lesions can lead to serious complications such as myocardial ischemia, arrhythmias, heart failure, and infective endocarditis. The proliferation of advanced imaging technologies—especially electrocardiogram (ECG)-synchronized coronary CT angiography and cardiac magnetic resonance (MR)—has allowed for a more detailed assessment of anatomical features, drainage patterns, and hemodynamic effects of CAFs, enabling a comprehensive diagnostic approach that goes beyond conventional echocardiographic methodology. The presence of symptoms, shunt ratio, anatomical complexity, and the risk of complications are the primary factors guiding therapeutic decisions. Transcatheter closure has become the preferred option in suitable cases due to its minimally invasive nature, while surgical ligation is still indicated for complex fistulas. In addition, pharmacologic therapy—including beta-blockers, calcium channel blockers, and antiplatelet agents—may be employed as a temporizing measure in select low-risk or pediatric patients. Risk stratification models incorporating anatomical and hemodynamic parameters are increasingly used to support treatment decision-making, particularly in asymptomatic cases. Long-term and regular follow-up is critical due to the risks of residual flow, coronary dilatation, and thromboembolic events in the post-procedural period. This review provides a comprehensive overview of current diagnostic and therapeutic approaches to CAFs and discusses clinical decision criteria to support individualized treatment planning and long-term follow-up strategies in a structured manner. There is still a need for multicenter, prospective studies on the timing of treatment and the selection of treatment modalities, especially in pediatric and asymptomatic patient groups.