Coronary artery fistulas: clinical and therapeutic considerations

Coronary artery fistulas vary widely in their morphological appearance and presentation. These fistulas are congenital or acquired coronary artery abnormalities in which blood is shunted into a cardiac chamber, great vessel, or other structure, bypassing the myocardial capillary network. The majority of these fistulas arise from the right coronary artery and the left anterior descending coronary artery; the circumflex coronary artery is rarely involved. Clinical manifestations vary considerably and the long-term outcome is not fully known. The patients with coronary fistulas may present with dyspnea, congestive heart failure, angina, endocarditis, arrhythmias, or myocardial infarction. A continuous murmur is often present and is highly suggestive of a coronary artery fistula. Differential diagnosis includes persistent ductus arteriosus, pulmonary arteriovenous fistula, ruptured sinus of Valsalva aneurysm, aortopulmonary window, prolapse of the right aortic cusp with a supracristal ventricular septal defect, internal mammary artery to pulmonary artery fistula, and systemic arteriovenous fistula. Although noninvasive imaging may facilitate the diagnosis and identification of the origin and insertion of coronary artery fistulas, cardiac catheterization and coronary angiography is necessary for the precise delineation of coronary anatomy, for assessment of hemodynamics, and to show the presence of concomitant atherosclerosis and other structural anomalies. Treatment is advocated for symptomatic patients and for those asymptomatic patients who are at risk for future complications. Possible therapeutic options include surgical correction and transcatheter embolization. Historical perspectives, demographics, clinical presentations, diagnostic evaluation, and management of coronary artery fistula are elaborated.