Coronary artery bypass surgery for coronary artery disease

Surgery Overview

During a coronary artery bypass, the diseased sections of your coronary arteries are bypassed with healthy artery or vein grafts to increase blood flow to the heart muscle tissue. This procedure is also called coronary artery bypass grafting (CABG). Bypass typically requires open-chest surgery.

There are several newer, less invasive techniques for bypass surgery that can be used instead of open-chest surgery in some cases. In some procedures, the heart is slowed with medicine but is still beating during the procedure. For these types of surgery, a heart-lung bypass machine is not needed. (For open-chest surgery, a heart-lung machine is needed to circulate the blood and to add oxygen to it.) Other techniques use keyhole procedures or minimally invasive procedures instead of open-chest surgery. Keyhole procedures use several smaller openings in the chest and may or may not require a heart-lung machine. These techniques are still being studied and may not be available in all medical centers.

The material in this section will focus on traditional open-chest bypass surgery. View the slideshow on CABG surgery to see what happens during a bypass.

In the past, the surgeon would remove a vein from elsewhere in the body (often from the leg) and attach it to the blocked artery or arteries in the heart. More recently, one or both mammary arteries, located on the inside of the chest wall—or a branch of one of the radial arteries, located in the arm, have been used to bypass the obstructed coronary vessel. These arteries tend to remain open longer than vein grafts.1 In either case, blood is redirected through the artery or vein graft, bypassing the blocked or narrowed artery and increasing blood flow to a region of the heart.

What To Expect After Surgery

After surgery, there will be a short stay (1 to 2 days if there are no complications) in the intensive care unit (ICU). In the ICU, the person will likely have:

  • Continuous monitoring of his or her heart activity.
  • A tube to temporarily help with breathing.
  • A stomach tube, to remove stomach secretions until the person starts eating again.
  • A tube (catheter) to drain the bladder and measure urine output.
  • Tubes connected to veins in the arms (intravenous, or IV, lines) through which fluids, nutrition, and medicine can be given.
  • An arterial line to measure blood pressure.
  • Chest tubes, to drain the chest cavity of fluid and blood (which is temporary and normal) after surgery.

You will typically stay in the hospital from 3 to 8 days after open-chest bypass surgery. The amount of time you stay varies and will depend on your health before bypass surgery and whether complications develop from surgery.

After discharge, recovery at home takes 4 to 6 weeks. Recovery includes physical therapy, respiratory therapy, occupational therapy, and diet counseling. Exercise and driving may be resumed after about 2 to 3 weeks. People who are able to return to work can usually do so within 1 to 2 months, depending on the type of work they do. Some people find that they experience heightened emotions (such as a greater tendency to cry or otherwise show emotion in ways that are unusual compared with before the procedure) for up to a year following surgery.

Why It Is Done

In general, bypass surgery may be preferred when:1

  • The left main heart artery is significantly narrowed.
  • All three arteries of the heart are blocked or have significantly reduced blood flow.
  • Blocked arteries cannot be treated with angioplasty or stenting.
  • Bypass surgery is likely to be more successful than angioplasty.
  • Certain factors such as the person's age, gender, overall health, previous bypass surgery, or other factors are too risky for angioplasty.
  • Surgery also is required to repair or replace a heart valve damaged by heart valve disease.

How Well It Works

Although the immediate risks of coronary artery bypass surgery are greater than those of angioplasty, long-term outcomes are similar for both procedures. Coronary artery bypass surgery offers the advantages of greater durability and more complete revascularization. Generally, the greater the extent of coronary atherosclerosis, the greater the benefits of bypass surgery over angioplasty.2

Bypass surgery may be considered a better option for some people who have:2

  • Diabetes .
  • Coronary artery disease in multiple blood vessels or in the left main vessel.

Bypass surgery often relieves symptoms of chest pain (angina), improves exercise performance, and reduces the risk of heart attack.

A person with severe coronary artery disease (CAD) has an increased risk of death during the first year after they receive bypass surgery. However, 5 to 10 years after bypass surgery, the risk of death from CAD is less for those who had surgery compared to those treated with medicine alone. Factors that affect this conclusion include the number of coronary arteries that are diseased, the severity of the disease in a person, and the location of plaque deposits in the coronary arteries.


The most common problem after surgery is the return of chest pain (angina).1 Severe angina may return shortly after bypass surgery in about 4 out of 100 people. After 5 years, about 3 out of 100 people may need another operation. Surgery is usually less successful when it needs to be repeated.3

Other risks of bypass surgery may include:

  • Risks associated with anesthesia.
  • Death.
  • Heart attack.
  • Stroke .
  • Excessive bleeding.
  • Infection.
  • Subtle problems in long-term memory, comprehension, calculation skills, and concentration.4
  • Blockage (occlusion) or narrowing of the artery or vein graft.

What To Think About

When bypass surgery is clearly needed, surgery improves symptoms and in some cases prolongs life. However, in many situations, the reasons for doing bypass surgery as opposed to other treatments are less clear.

Studies indicate bypass surgery may be preferred over angioplasty for people with diabetes.1

People are encouraged to ask their doctor what they can expect from bypass surgery compared with other forms of treatment. Bypass surgery does not cure coronary artery disease and does not affect the process of hardening and narrowing of arteries. A person can still develop new blockages in the new blood vessels used to bypass blocked arteries as well as in the original coronary arteries. Reducing risk factors and slowing the rate of atherosclerosis are vital to successful long-term results. Lowering cholesterol when it is high, stopping smoking, and controlling high blood pressure and diabetes are important in anyone who receives bypass surgery.

In each case, the cardiac surgeon or cardiologist should be able to clearly explain why bypass surgery is preferred over medicine or angioplasty. Sometimes, a second opinion can be helpful when it is not clear that surgery needs to be done. For more information, see:

Click here to view a Decision Point. Should I have coronary artery bypass graft (CABG) surgery?

More information

Complete the surgery information form (PDF)(What is a PDF document?) to help you prepare for this surgery.



  1. Eagle KA, et al. (2004). ACC/AHA 2004 guideline update for coronary artery bypass graft surgery: Summary article. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1999 Guidelines for Coronary Artery Bypass Graft Surgery). Circulation, 110(9): 1168–1176.
  2. Smith SC Jr, et al. (2006). ACC/AHA/SCAI 2005 guidelines update for percutaneous coronary intervention: Summary article. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). Circulation, 113(1): 156–175.
  3. Douglas JS (2003). Percutaneous intervention in patients with prior coronary bypass surgery. In EJ Topol, ed., Textbook of Interventional Cardiology, 4th ed., pp. 317–344. Philadelphia: Saunders.
  4. Newman MF, et al. (2001). Longitudinal assessment of neurocognitive function after coronary artery bypass surgery. New England Journal of Medicine, 344(6): 395–452.

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