Computed tomographic characteristics of congenital coronary artery fistulas in an adult population

Background: Coronary artery fistulas (CAFs) are usually congenital coronary artery anomalies of termination.Aims: This study aimed to assess the prevalence, anatomic characteristics, and clinical significance of CAFs detected by computed tomography (CT) in an adult population.Methods: We performed 45 817 CT examinations in 39 066 subjects between 2008 and 2020. The electronic database was manually checked using specific keywords to identify patients with CAFs. The CT characteristics of CAFs were evaluated. CAF was defined as clinically significant if it was the most plausible cause of myocardial infarction, infective endocarditis, heart failure, death during follow-up, hospitalization, or if it required either percutaneous or surgical intervention.Results: Of 39 066 patients, 56 CAFs were detected in 42 subjects (20 men, 47.6%) with a prevalence of 0.11%. Most CAFs originated from the right coronary artery (RCA) (48.2%) and drained into the pulmonary artery (PA) (58.9%). CAFs terminating in the PA were more frequently multiple (P <0.001) and tortuous (P <0.001) as compared to CAFs without PA drainage. Clinically significant CAFs, identified in 7 of 42 patients, were more common in younger (P = 0.03) and male (P = 0.04) subjects and had larger lumen area and diameter at the site of origin (P = 0.03, P = 0.03, respectively).Conclusions: In the unselected adult population undergoing coronary CT angiography, the RCA and the PA are the most common sites of origin and termination of CAFs, respectively. CAFs draining into the PA are more often multiple and tortuous. Clinically meaningful CAFs are larger and most frequently detected in younger and male patients.