Bypass surgery is also called coronary artery bypass graft (CABG) surgery and is used to treat coronary artery disease (CAD) and reduce the risk of a heart attack. The heart muscle contains coronary arteries that feed it oxygen-filled blood. When those arteries become clogged, the heart cannot receive the proper amount of oxygenated blood. If the arteries are not fixed, the heart could suffer permanent damage. This cardiac surgery is usually recommended for individuals who have multiple blockages in the coronary arteries or patients who have not responded well to other treatments. The blockages in the coronary arteries are bypassed using grafts made from other blood vessels in the body.