Also known as "bypass surgery," a coronary artery bypass graft uses a blood vessel taken from the leg, chest or arm. In most cases, this vessel is attached to the aorta and to the coronary artery below the narrowed area, thus creating a bypass around the blockage. In some cases, multiple areas of the coronary arteries are bypassed during the same procedure.

In general, surgery is rarely performed at the time of an acute heart attack because of the usual delay in restoring blood flow to the blocked artery. Emergency bypass surgery may be needed if angioplasty cannot reach or sufficiently open a blockage, or if the blockage is too long or complex for angioplasty.

In certain cases, such as in diabetic patients with multiple blocked coronary arteries, bypass surgery may be preferred.