An unusual pair: coronary artery fistula and coronary sinus ostium stenosis as a cause of refractory angina.

Coronary fistula draining to the CS are rare, and association with CS ostial stenosis has been reported very infrequently. CS ostial stenosis can cause elevated coronary venous pressure, leading to decreased global coronary perfusion and symptoms of angina or heart failure. Previous case reports of coronary fistula and CS ostial stenosis were treated with either medical therapy or surgery, and our case is the first to our knowledge to report successful percutaneous treatment.