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As with all types of surgery, a coronary artery bypass graft (CABG) carries risks of complications.

Some of the main complications associated with a coronary artery bypass graft are covered on this page.

Irregular heartbeat

Some people develop atrial fibrillation, a condition that causes an irregular and often abnormally fast heart rate.

But this isn't usually serious if found early and can normally be easily treated with a course of medication.


The wounds in your chest and arm or leg (depending on where the grafted blood vessels were removed) can become infected after a coronary artery bypass graft.

Infection can also affect your lungs or the inside of the chest after having a coronary artery bypass graft.

Most infections that do develop after the procedure can usually be treated successfully with antibiotic tablets or injections.

Reduced kidney function

Some people experience reduced kidney function after surgery.

In most cases, this is only temporary and the kidneys begin working normally after a few days or weeks.

In rare cases, you may need to have temporary dialysis until your kidneys recover.

This involves being attached to a machine that replicates the functions of the kidneys.

Brain-related problems

Some people experience some problems with their memory after a coronary artery bypass graft and also find it difficult to concentrate on things like reading a book or newspaper.

This will usually improve in the months following the operation, but it can sometimes be permanent.

There's also a risk of serious problems affecting the brain during or after a coronary artery bypass graft, such as a stroke.

Heart attacks

Both the heart and the coronary arteries that supply the heart with blood are in a vulnerable state after a coronary artery bypass graft, particularly during the first 30 days after surgery.

Some people who have a coronary artery bypass graft have a heart attack during surgery, or shortly afterwards.

Who's most at risk?

Following a coronary artery bypass graft, there are several factors that increase your risk of developing complications.

These include:

  • your age – your risk of developing complications after surgery increases as you get older
  • having another serious long-term health condition – having a condition such as diabetes, chronic obstructive pulmonary disease (COPD) or severe chronic kidney disease can increase your risk of complications
  • being a woman – women tend to develop coronary artery disease later than men; it's thought this may lead to a higher risk of experiencing complications because they're generally older at the time of surgery
  • having emergency surgery to treat a heart attack – emergency surgery is always riskier because there's less time to plan the surgery, and the heart can be seriously damaged from the heart attack
  • having 3 or more vessels grafted – the more complex the operation, the greater the chance that complications will occur
  • being obese – if you're obese, the surgeon will have to make a deeper cut to gain access to your heart, which has a higher risk of becoming infected

Your surgical team will be able to provide you with more detailed information about any specific risks before you have surgery.