Coronary artery bypass grafting (CABG) is a type of surgery that improves blood flow to the heart. It's used for people who have severe coronary heart disease (CHD), also called coronary artery disease.
CHD is a condition in which a substance called plaque (plak) builds up inside the coronary arteries. These arteries supply oxygen-rich blood to your heart. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood.
Plaque can narrow or block the coronary arteries and reduce blood flow to the heart muscle. If the blockage is severe, angina (an-JI-nuh or AN-juh-nuh), shortness of breath, and, in some cases, heart attack can occur. (Angina is chest pain or discomfort)
CABG is one treatment for CHD. During CABG, a healthy artery or vein from the body is connected, or grafted, to the blocked coronary artery. The grafted artery or vein bypasses (that is, goes around) the blocked portion of the coronary artery.
This creates a new passage, and oxygen-rich blood is routed around the blockage to the heart muscle.
Figure A shows the location of the heart. Figure B shows how vein and artery bypass grafts are attached to the heart.
As many as four major blocked coronary arteries can be bypassed during one surgery.
CABG is the most common type of open-heart surgery in the United States. Doctors called cardiothoracic (KAR-de-o-tho-RAS-ik) surgeons do this surgery.
CHD isn't always treated with CABG. Many people who have CHD can be treated other ways, such as with lifestyle changes, medicines, and a procedure called angioplasty (AN-jee-oh-plas-tee). During angioplasty, a small mesh tube called a stent may be placed in an artery to help keep it open.
CABG or angioplasty with stent placement may be options if you have severe blockages in your large coronary arteries, especially if your heart's pumping action has already been weakened.
CABG also may be an option if you have blockages in the heart that can't be treated with angioplasty. In this situation, CABG is considered more effective than other types of treatment.
If you're a candidate for CABG, the goals of having the surgery include:
You may need repeat surgery if the grafted arteries or veins become blocked, or if new blockages develop in arteries that weren't blocked before. Taking medicines as prescribed and making lifestyle changes as your doctor recommends can lower the chance of a graft becoming blocked.
In people who are candidates for the surgery, the results usually are excellent. Following CABG, 85 percent of people have significantly reduced symptoms, less risk of future heart attacks, and a decreased chance of dying within 10 years.