Blockage of the arteries that supply blood to the heart (coronary heart disease) causes more deaths in the United States than any other condition. Many people with coronary heart disease undergo invasive procedures, such as coronary artery bypass graft surgery (CABG) or percutaneous transluminal coronary angioplasty (PTCA), to bypass or unblock clogged arteries. These procedures relieve chest pain and improve survival in some, but not all, patients with coronary heart disease. Research shows that white patients in the United States more commonly receive procedures for coronary heart disease than do African- American patients, even though coronary heart disease is more common in African- American patients than white patients. Some studies also show that CABG surgery and PTCA are “overused”; that is, they are performed even when they will probably not benefit patients. How much of the greater use of CABG surgery and PTCA among white patients in the United States is due to overuse is not known.