Characteristics of Coronary Artery to Pulmonary Artery Fistula on Coronary Computed Tomography Angiography

Objective: The aim of the study was to evaluate the characteristics of coronary artery-to-pulmonary artery fistula (CPAF) found by coronary computed tomography (CT) angiography. Methods: Among 10,121 cases of coronary CT angiography performed for 7 years, we found 32 cases of CPAF. We retrospectively evaluated the demographics, clinical symptoms, and anatomical characteristics such as the origin, number of origins, course, opening site of the fistula, and the presence of aneurysmal changes (defined as dilatation 1.5 times the diameter of the origin). We also categorized the fistula openings according to size compared with that of the proximal left anterior descending coronary artery. Results: The patients were 14 men and 18 women with a mean (range) age of 56.5 (34-86) years. Nineteen patients had no related symptoms, and the other 13 patients had symptoms such as angina, chest discomfort, palpitations, or shoulder pain. Among these patients, 2 patients were diagnosed with coronary artery disease. The origins of CPAF were single (n = 15, 46.9%) or multiple (n = 17, 53.1%). The CPAFs arose most commonly from the conus branch of the right coronary artery (n = 20, 62.5%) and proximal left anterior descending (n = 17, 53.1%). All CPAFs coursed anteriorly to the main pulmonary artery and drained into the anterolateral aspect. Twenty-five patients (78.1%) exhibited aneurysmal changes. The openings were small in 13 (40.6%), medium in 13 (40.6%), and large in 6 (18.8%) patients. Conclusions: More than half of patients with CPAF had no related symptoms. Coronary artery-to-pulmonary artery fistula may have a single origin or multiple origins. All of the CPAFs coursed anteriorly to the main pulmonary artery and drained into the anterolateral aspect; the CPAFs identified here frequently exhibited aneurysmal changes