Massively enlarged right coronary artery with fistula to the coronary sinus: To close or not to close?

Background: Coronary arteriovenous fistulae are direct connections from a coronary artery to a cardiac chamber or large vessel and may be acquired or congenital. Symptomatic patients may have dyspnea or myocardial ischemia. Case: A 72-year-old man presented with worsening shortness of breath, atrial fibrillation, signs of heart failure, elevated cardiac enzymes and severe aortic regurgitation. In the evaluation prior to aortic valve repair, computed tomography angiography showed massive enlargement of his right coronary artery up to 2.0 cm in diameter with a large cameral fistula tract into the ostium of the coronary sinus and then to the right atrium. During coronary angiography, a power injection device was required to opacify the vessel for cineangiography. Echocardiography revealed a left ventricular ejection fraction of 45% and decreased right ventricular systolic function with a right ventricular systolic pressure of 45.1 mm Hg. A large left-to-right shunt was present by echocardiography and cardiac magnetic resonance imaging with a Qp/Qs of 1.7, and thus deemed significant. Decision Making: Coronary arteriovenous fistulae repair is indicated in the setting of ischemia or shunt-related symptoms such as dyspnea. A shunt flow of Qp/Qs greater than 1.5 is commonly the threshold for repair. Complications such as bacterial endocarditis, thrombosis, aneurysm formation, dissection or rupture may occur in untreated patients. This patient showed symptoms, decline in left and right ventricular function and a significant shunt flow. While various options for repair are now available, including catheter-based closure with coils or embolization, surgical ligation of this fistula was chosen because the patient was to undergo aortic valve repair. Conclusions: Coronary arteriovenous fistulae are rare occurrences that are often incidentally diagnosed. Clear indications for correction of these fistulae are available and may prevent devastating future complications