We present a case of a 62-year-old man who was in cardiogenic shock. He had a history of coronary artery bypass grafting 4 years previously, with left internal mammary radial artery Y-grafting to a left dominant coronary circulation. Critical stenoses of the left main coronary and left subclavian arteries were seen at angiography. An occluded abdominal aorta precluded the use of mechanical circulatory support. The patient underwent high-risk stenting of the left subclavian artery with a successful outcome. The case highlights the unresolved issue of screening for subclavian stenoses in patients being considered for revascularization with arterial Y-grafting.