Blockage of the arteries that supply blood to the heart (coronary heart disease or CHD) causes more deaths in the United States than any other condition. Many people with CHD undergo procedures, such as percutaneous transluminal coronary angioplasty (PTCA), to unblock clogged or narrowed arteries. PTCAs relieve chest pain and may improve survival in some patients with CHD. For standard PTCA, a physician threads a thin tube (catheter) through blood vessels and uses a balloon attached to the tip of the catheter to widen the arteries that have been narrowed by disease. For PTCAs with stents, a physician inserts a small metal or plastic tube into a narrowed artery and leaves it there to help keep the artery open. Patients having PTCAs often get stents, even though they cost more than standard PTCAs. A summary of the studies that have compared the two procedures would help physicians and patients understand the benefits of each.