Saphenous Vein Graft-to-Pulmonary Artery Fistula Presenting With Coronary Ischemia and Right Ventricular Dysfunction.

BACKGROUND: Acquired coronary and coronary-cameral fistulas are rare after coronary artery bypass grafting (CABG), and saphenous vein graft fistulas are exceptionally uncommon, especially without graft aneurysm. CASE SUMMARY: A 61-year-old man with previous CABG presented with typical chest pain, elevated high-sensitivity troponin, and a continuous murmur. Echocardiography showed impaired right ventricular function. Coronary angiography revealed patent grafts, distal graft stenosis, and a sequential saphenous vein graft-to-left pulmonary artery fistula, confirmed by coronary computed tomography without graft aneurysm. The patient declined invasive treatment and remained asymptomatic on maximal medical therapy at 6 months. DISCUSSION: Most post-CABG fistulas to the pulmonary vasculature arise from the left internal mammary artery and may cause coronary steal syndrome. Saphenous vein graft fistulas are much rarer and are usually associated with graft aneurysm. This case is unique because the fistula occurred without aneurysmal degeneration. TAKE-HOME MESSAGE: A saphenous vein graft-to-pulmonary artery fistula is a rare post-CABG complication presenting with angina, continuous murmur, or right ventricular dysfunction, requiring multimodal diagnosis and individualized treatment.