Internal mammary arteries (IMA) as conduits in coronary artery bypass grafting are superior to saphenous vein grafts. If there is subclavian artery stenosis (SAS) proximal to the IMA graft, impairment of flow to the IMA may occur. If the stenosis is severe, retrograde flow from the grafted coronary artery to the brachial artery may lead to angina. Following the identification of 2 cases of angina secondary to subclavian artery stenosis at their institution, the authors prospectively performed arch angiography in a cohort of patients with manifestations of peripheral vascular disease undergoing diagnostic coronary angiography to assess the prevalence of subclavian stenosis. Fifty-two patients were enrolled in the protocol, with 48 patients having technically acceptable studies. Of these 48, 41.6% had measurable stenosis of at least one of the brachiocephalic arteries, with 35% of patients with at least a 30% stenosis of the left subclavian artery and 18.7% with more than 50% stenosis. They conclude that patients with significant peripheral vascular disease undergoing coronary angiography who are potential candidates for revascularization may benefit from arch angiography as part of their initial evaluation.