Coronary fistulas can develop collateral vessels: angiographic follow-up of an embolized giant right coronary artery-superior vena cava fistula in a patient with variant angina

A 54-year-old man was transferred to our emergency department because of acute inferior myocardial infarction. However, ST-segment elevation resolved after intravenous nitrate administration on admission and coronary angiography revealed a nonobstructive atherosclerotic plaque at the mid-portion of the circumflex artery and a giant tortuous fistula from the right sinus of Valsalva to the superior vena cava. The patient was diagnosed with variant angina and coronary arteriovenous fistula after vasodilator treatment and maximal treadmill stress test. After effective medical treatment of variant angina and successful percutaneous coil embolization of the fistula, the patient had not experienced any angina episodes for 1 year. However, control coronary angiography revealed partial persistence of fistula flow because of new collateral vessels, bridging distal and proximal parts of the occluded segment. We present the first coexistence of coronary to superior vena cava fistula and variant angina in the literature. This report also shows the ability of coronary fistulas to develop collateral vessels, like coronary arteries.