Coronary artery bypass graft (CABG) surgery is used to treat coronary heart disease — a condition caused by a build-up of plaque in the arteries that supply blood to the heart.

The surgery involves bypassing the narrowed sections of these arteries to ensure your blood can flow without restriction.

While CABG surgery can effectively reduce symptoms and reduce your risk of further heart complications, it cannot cure coronary artery disease completely. However, it can be an essential treatment when it comes to improving the overall health of your heart.

What is CABG?

Coronary artery disease occurs when plaque builds up on the inside of your arteries. Over time, this can lead to a variety of complications such as heart failure. CABG surgery helps reduce the risk of this happening and allows you to effectively manage any associated symptoms.

Some associated symptoms of coronary artery disease can include:

  • chest pain or discomfort, including angina
  • light-headedness and dizziness
  • shortness of breath

During CABG surgery, the heart surgeon grafts a blood vessel between the aorta (the main artery leaving the heart) and a point in the coronary artery beyond the narrowed or blocked area. This diverts your blood flow past any narrowed sections of arteries so that your heart doesn’t have to work as hard to pump blood around your body.

The surgery aims to help you manage any specific symptoms of coronary artery disease, but healthy lifestyle choices should be incorporated for the most effective, long-lasting results.

An illustration showing how coronary heart disease is cause by a build up of plaque in the arteries

Coronary artery disease occurs when plaque builds up inside the arteries.

What to expect during a coronary artery bypass grafting

During the CABG procedure, the surgeon will take a healthy blood vessel from your leg, chest or arm and use it to bypass the section of blocked or narrowed coronary arteries. This then creates a new pathway for your blood to flow through, enhancing your supply and circulation.

We utilise endoscopic vein harvesting to do this — a minimally invasive technique of harvesting grafts.

Traditionally, CABG surgery involves using a heart-lung bypass machine to perform the functions of your heart and lungs while the operation is taking place. This gives the traditional procedure the name ‘on-pump CABG’.

During the procedure, an incision will be made in your chest and your chest bone will be opened to access your heart more easily. The graft can then be completed with the new healthy blood vessel before your chest is closed back up again.

Unfortunately, stopping the heart and using a heart-lung bypass machine can result in inflammation throughout the body and prevent multiple organs from working as they should. This increases the risk of complications in some patients, such as those with kidney problems or diabetes (called ‘high-risk patients’).

Our specialist cardiac surgeons at Royal Brompton and Harefield hospitals offer two alternative CABG procedures for high-risk patients that can help improve recovery times and safety. These are called ‘off-pump CABG’ and EndoACAB, and are detailed below.

Off-pump CABG

An off-pump CABG surgery, also called a ‘beating heart bypass’,  is a complex procedure requiring greater surgical skill. However, it can greatly improve surgical outcomes, particularly for patients who are at high risk for traditional on-pump surgery.

During the procedure, which is also performed with the chest open, a device is used to stabilise the heart while the surgeon operates. As the heart continues to beat, a heart-lung bypass machine is not required.

A study on over 10,000 patients at Harefield Hospital demonstrated that off-pump CABG was associated with a lower risk of death during surgery, fewer complications after surgery and a similar chance of surviving when followed up after 20 years when compared to traditional on-pump CABG.


Another variation of CABG surgery is called endoscopic atraumatic coronary artery bypass grafting (EndoACAB). This is a minimally invasive surgery where smaller incisions are made between your ribs, enabling the surgeon to access your heart without having to open your chest bone. This method can shorten your recovery time due to less trauma occurring to your body.

Elderly people may benefit the most from undergoing a minimally invasive technique, as traditional surgery can be too much for older bodies to handle.

Younger people generally recover well from traditional open-heart surgery as their bodies are still young enough to cope with the trauma it can cause to the body.

Our surgeons will recommend the best CABG procedure based on your personal needs. As Royal Brompton and Harefield hospitals are both specialist high-volume centres for cardiac surgery operating on many patients each year, our cardiac surgeons have the skill to perform all types of CABG to the highest standard.

How to prepare for a CABG

Before you have CABG surgery, you will need to prepare in advance for the procedure and recovery. Your doctor will advise you on if and when you need to stop taking any medications, eating or drinking.

You will also need to arrange for transportation to and from the hospital as you will be unable to drive for around six weeks after your operation.

If there are any specific preparations you need to make beforehand, your doctor will let you know so that you can feel comfortable and ready for your surgery — both before and after.

CABG results and recovery

After your surgery, you will need to stay in the hospital for around seven days so that you can be monitored. Most people make a full recovery within 12 weeks, but this can depend on your overall health and whether there were any complications during the surgery.

Within the first few days of being home, you should be able to walk short distances, cook and lift light objects. After six weeks, you may be recovered enough to start driving again, carry slightly heavier objects and have sex. Most people will return to work in six to eight weeks, but this will depend on your recovery.

Recovery times with off-pump CABG and EndoACAB may be shorter than traditional on-pump CABG and your surgeon can provide more detail.

The benefits of having CABG surgery can include a reduction of your symptoms and a greatly reduced risk of heart disease-related complications and death.

However, to maintain these results over the long term, you will need to lead a healthier lifestyle to keep your heart as healthy as possible. Certain lifestyle changes might include:

  • always going for regular check-ups on your heart
  • exercising regularly
  • eating a well-balanced diet
  • lowering your stress levels
  • getting enough sleep
  • cutting back on alcohol

Alternatives to CABG

If the arteries around your heart are severely damaged, a coronary angioplasty may be recommended in place of a CABG procedure. This will involve inserting a thin catheter into one of the blood vessels in your arm or groin, before guiding it to your heart with the help of an X-ray.

A balloon is also attached to the catheter to inflate and widen the narrowed artery.

Sometimes a metal tube (stent) will also be left in the section of the inflated artery to keep it open.

Other alternatives to CABG surgery can include taking medication, such as:

  • antiplatelets to prevent your blood from clotting
  • statins to reduce high cholesterol
  • beta-blockers to reduce the risk of angina and lower high blood pressure

These medications can help manage your symptoms of coronary heart disease, but a CABG surgery may be recommended over them if your condition is severe or you have a heightened risk of heart attacks.

The benefits of coronary artery bypass grafting

A successful surgery will reduce your symptoms from coronary heart disease, such as angina and shortness of breath, as well as improve your quality of life.

This type of surgery also reduces the risk of future heart attacks. In patients with severe coronary artery disease, CABG may improve their life expectancy.

Risks of CABG surgery

Every surgical procedure carries some risks and CABG surgery is no exception. However, it’s important to bear in mind that complications arising during this surgery are very rare and choosing expert cardiac surgery centres like Royal Brompton and Harefield hospitals can help minimise risks even further.

Risks associated with CABG surgery commonly include:

If you have any questions about the risks associated with CABG surgery, speak to your doctor and they will be happy to clear up any concerns you may have.

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