The arteries that bring blood to the heart muscle (coronary arteries) can become clogged by plaque (a buildup of fat, cholesterol and other substances, due to diet, smoking or genetic factors). This can slow or stop your blood flow through the heart's blood vessels, leading to chest pain or a heart attack. Increasing blood flow to the heart muscle often relieves these symptoms and reduces the risk of heart attack.

The surgery involves sewing a section of vein from the leg or artery from the chest or another part of the body to bypass the clogged part of your diseased coronary artery. This creates a new route for blood to flow, so that the heart muscle will get the oxygen-rich blood it needs to work properly. After completing the graft, the surgical team restarts your heart, and closes up the incision.