Prevalence, management, and prognosis of isolated coronary artery fistulas: a 12-year single-center retrospective computed tomographic study

Background: With the increasing use of coronary computed tomography angiography (CCTA), isolated coronary artery fistulas (ICAFs) are increasingly identified during routine or non-targeted imaging, but the large-scale epidemiological and anatomical data remain limited. This study aims to explore the prevalence, anatomical features, and clinical manifestations of ICAFs in adults who underwent CCTA. Methods: A retrospective analysis was performed on 378,556 consecutive adult patients who underwent CCTA at Fuwai Hospital between 2010 and 2022. Two experienced radiologists independently reviewed CCTA images to confirm the presence of ICAFs and assess their anatomical features, including origin, drainage site, and size. Demographic, clinical, and procedural data were analyzed to evaluate associations with symptoms and treatment strategies. Results: A total of 252 adult patients with ICAFs were identified, yielding a prevalence of 0.07%. The mean age was 48.29±15.03 years, and 47.20% were male. The majority originated from the anterior descending artery (30.56%) and drained into the pulmonary artery (62.3%). The mean diameter of the fistula was 7.30±5.19 mm with 32.54% categorized as with large ICAFs. Symptomatic ICAFs patients were younger than asymptomatic patients (43.81±14.18 vs. 52.05±14.73 years, P=0.016). The average diameter of the draining site was larger in symptomatic ICAFs group (7.95 vs. 5.85 mm, P=0.033). Among the whole cohort, 70 patients underwent transcatheter closure and 28 patients underwent surgical closure, with no significant differences in baseline characteristics. The clinical efficacy was similar between both groups, however, transcatheter closure was infeasible in 15.71% of the attempted cases. Most untreated ICAFs patients maintained their physical activity levels and barely underwent follow-up assessments. Conclusions: The prevalence of ICAFs was 0.07% among adult population who underwent CCTA. Large-sized ICAFs was the anatomical features significantly associated with clinical symptoms.