Coronary artery bypass surgery (CABG)

Also known as coronary artery bypass graft (CABG) surgery

Coronary artery bypass graft (CABG) surgery is a type of operation used to restore blood flow to the heart muscle. It involves having a blood vessel from another part of the body grafted between the main artery leading from the heart and the coronary artery in order to bypass a narrowed or blocked segment of a coronary artery.

What is coronary artery bypass graft surgery?

A coronary artery bypass graft (CABG) surgery is used to restore blood flow.  Sometimes one, two, three or four grafts may be needed, otherwise known as a double, triple or quadruple bypass. The surgery results in improved blood flow to the heart muscle, relieving angina (chest pain) symptoms. Long term lifestyle changes are also needed to maintain the benefits of surgery.

Why is CABG surgery undertaken?

CABG surgery is performed primarily to relieve angina symptoms. In most cases angina is caused by coronary artery disease. This occurs when fatty deposits build up under the lining of the coronary arteries (the vessels supplying blood to the heart muscle). As a result, these arteries become narrowed and blood flow to the heart muscle is reduced.

By improving blood flow to the heart muscle, surgery can result in a more active and better quality of life, with less or no angina and less requirement for medication. Choosing and maintaining positive lifestyle changes are of significant help in preventing a recurrence of angina symptoms.

What is a coronary artery graft?

The graft is usually a small length of vein which is taken from the leg (the saphenous vein), the chest wall (internal mammary artery), or an artery from the arm (radial artery). The grafts are joined from the aorta (main artery leading from the heart) to one of the branches of the coronary arteries. This bypasses the blockage or narrowing, providing a new channel that allows blood to flow to the heart muscle.

If the internal mammary artery is used as a graft, it remains attached to its own blood supply with the free end sewn onto the coronary artery, bypassing the blockage or narrowing.

What happens during the operation?

The surgeon will make a cut (incision) down the middle of your chest, through the breastbone (sternum) to reach the heart. While your heart is being operated on, it is usual for it to be temporarily be stopped. During this time, the flow of blood to the heart and lungs is re-routed through a heart-lung bypass machine. The machine takes over the heart’s job of pumping and the lungs' job of breathing.

Alternatively, some surgeons perform off-pump bypass surgery, where they operate without using the bypass machine. CABG surgery usually takes between three and six hours, depending on what is required.

There may be an incision in either your leg or arm, depending on where the vein graft has been taken from. For the first few days following your operation, these will be bandaged or covered by a dressing. A procedure that is becoming more available is endoscopic vein harvesting. In this method, the vein from the leg is harvested using up to three small incisions, thereby reducing scarring.

Preparing for your operation

There are a few routine investigations you need to have done as preparation for your surgery. These include an ECG (electrocardiogram), chest x-ray, and blood tests. You will also need to look at lifestyle issues (eg, quitting smoking), organise your work and business arrangements so these are not a concern while you are recovering from the operation, and prepare yourself emotionally. You should discuss any questions and concerns with your doctor or nurse beforehand. Some of these issues are discussed below.


If you smoke, it is strongly advised that you quit. Quitline 0800 778 778 can help with support when you decide that you want to stop smoking. Surgeons and anaesthetists are very reluctant to work on those who continue to smoke, because of the associated breathing complications after surgery and the increased risk of blocking the new grafts.

Work and legal issues

The recovery period after surgery is about two to three months. You should inform your employer that you intend to return to work within six to 12 weeks and arrange sick leave accordingly.

Travel arrangements

If it is necessary for you to be transferred to another centre for surgery, the referring hospital normally meets the cost of your travelling expenses. Your specialist will be able to advise you about who to contact for such arrangements.

Accommodation for relatives

Cardiac surgical units try to help with accommodation or other social, emotional or practical problems which may arise when patients have major surgery away from their home town. If you need help, you should contact the social work department of the hospital concerned.

After the operation – what should I expect?

After the operation, you will be closely monitored in the Intensive Care Unit (ICU) for between 12 and 24 hours. You may feel a little disorientated and will be quite sleepy.

Once back on the ward, your progress will be monitored. Your medications will be changed as your body adjusts to the operation. You will probably be a bit sore after the operation and will need to have pain relief, which the nurses will arrange.


Getting up and about as soon as possible after surgery is encouraged to prevent problems developing. The physiotherapist will visit you soon after your surgery and will help you get back on your feet as early as day one or two following your surgery. You can help your recovery process by practicing the exercises you are taught.

The physiotherapist will assist you with:

  • Early mobilisation, breathing exercises and supported coughing to improve lung function.
  • The best ways to move so as to minimise wound discomfort.
  • Advice on an exercise programme/physical activity to improve your fitness on discharge.
  • Advice on your gradual return to normal work and leisure activities.

The recovery process

You will usually be in hospital for about five to seven days after the operation. During your recovery, you may have to wear supportive stockings in hospital and possibly for a short while when you are home. This is to prevent blood clots in your legs, known as deep vein thrombosis (DVT).

As the muscles, bones and joints of the chest wall need time to heal, avoid lifting heavy objects and doing movements that place stress on your chest area. Your physiotherapist and nurse can advise you.

Your cardiothoracic team will advise you when you can go home. It is important to discuss any concerns/questions with a member of the team, before discharge. Before going home you must ensure that someone can look after you for between 10 and 14 days after discharge. You must not go home alone.

You should continue your exercises when you leave hospital as this will help to relieve the aches and pains in your chest wall and shoulders. It takes about three months for the bones to heal so you will have to expect some discomfort in the front of the chest during healing.

You should work to a plan of gradually increasing daily activities, particularly walking. Follow the activity guidelines given to you prior to discharge.

Healing of scars

The scars on your arms and legs may need dressings until they are well healed. If there is any swelling, you should rest with the affected limb elevated for an hour or two. To help with swelling, your doctor may advise you to wear support stockings. The tissue beneath the scars may feel hard and tender, but eventually it will feel normal. There is often some numbness and tingling around the scars, which will also gradually disappear as the body heals.

Feelings and relationships

Many patients feel a little anxious about leaving the security of hospital to go home. This is quite normal after an operation - you might find it helpful to talk about your feelings with close family members or friends. Partners may also experience similar concerns.

These feelings should ease as your life returns to normal. However, for some, the anxiety may become more severe and it is important to seek help for this or for depression. Contact your cardiac rehabilitation nurse, social worker or family doctor to discuss your feelings with them. You can also contact the Depression helpline or get information from the Mental Health Foundation.

A heart healthy lifestyle

The CABG operation is a treatment, not a cure, for heart disease. The best way to prevent further heart disease is by reducing or removing any risk factors. Every risk factor you reduce or remove can have a major effect on lowering your chances of having further heart disease problems such an angina or a heart attack.

Undertaking a cardiac rehabilitation programme will provide you with information and support on how to tackle your risk factors and lead a healthy lifestyle.

Cardiac rehabilitation

Cardiac rehabilitation programmes offer you and your family information and support on a variety of cardiac related subjects and support you in your recovery. Programmes are available in most centres. Contact nursing staff prior to discharge, your doctor, or the Heart Foundation branch in your area.

Getting behind the wheel again

The New Zealand Transport Agency (NZTA) guidelines state that you must not drive for at least four weeks following heart surgery. You must also have an assessment by a specialist before returning to driving.

If you hold a vocational licence and drive, eg, passenger vehicles, trucks, fork lifts, courier vans or fly aeroplanes, different rules apply. Generally, you can apply to start driving three months after your surgery. Your licence needs to be approved by a cardiologist or specialist who has examined you and ensured you are safe to drive. It also pays to check with your insurance company to ensure you are fully covered.

What about sex after surgery?

A healthy sex life is part of returning to a normal life after a heart event. It can be very beneficial for your relationship, helping you feel secure and happy. While it may take a little while for you to feel like having sex, the desire should soon return. Try to take things slowly, making an effort to discuss your feelings and concerns with your partner.

The amount of energy needed for sexual intercourse is about the same as walking up two normal flights of stairs briskly, so it will not unduly affect your heart. You will need to find a position that is comfortable and doesn’t place any stress on your chest or restrict your breathing. Avoid positions where your arms are supporting your body weight.

Learn more          

Coronary artery bypass surgery Heart Foundation of New Zealand
Coronary arteries – Explained Watch, Learn, Live: Interactive Cardiovascular Library – American Heart Association
Coronary bypass surgery – Explained Watch, Learn, Live: Interactive Cardiovascular Library – American Heart Association

Credits: Editorial team.