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Coronary Artery Bypass Grafting (CABG)

Coronary Artery Bypass Grafting (CABG):  Symptoms, Causes and Risk Factors, Treatments | SingHealth

Coronary Artery Bypass Grafting (CABG) - What is it for

Coronary artery bypass grafting (CABG), also known as heart bypass surgery, is an open heart surgery which is a major operation where the surgeon opens up the chest and uses veins and/or arteries to bypass blocked or narrowed blood vessels in the heart. It is an established operation, which is usually recommended to patients with coronary artery blockages to relieve the symptoms of
coronary artery disease.

Coronary artery bypass grafting is typically an open heart surgery

What is coronary artery disease?

Coronary artery disease is caused by hardening and subsequent blockage of the arteries that supply blood to the heart. The obstruction of the coronary arteries reduces the amount of blood reaching the heart muscle, resulting in chest pain called angina pectoris. In severe cases, this may cause a life-threatening heart attack, scarring of the heart or heart failure. 

The mainstay of treatment for coronary artery disease is medication, while some patients will require invasive intervention such as CABG.

How is coronary artery bypass grafting done?

A bypass graft vessel allows oxygenated blood to bypass the blocked arteries and restore blood flow to the heart

In a CABG operation, the patient will be given a general anaesthetic before the chest is opened through the breastbone. A new graft vessel, which is a healthy artery or vein is taken from the patient’s leg, arm or chest, is surgically removed and sewn around the areas of the blockage by the surgeon. 

The graft vessel supplies oxygenated blood to the part of the heart that needs it, thereby “bypassing” the blocked arteries and restoring blood flow to the heart muscle. The augmented blood flow improves symptoms, reduces the need for medications, and prolongs life in well-selected patients. More blood flow reduces angina and should also reduce the need for medication. The number of grafts needed will depend on the severity of the patient’s condition.

One or more plastic chest drains may be left in the chest temporarily to drain any fluid that may have collected during the surgery. If necessary, pacing wires may be temporarily left in the heart for heart rhythm control. The breastbone is then wired together and the skin wounds closed with self-dissolving sutures.
On-pump surgery
The traditional coronary artery bypass grafting (CABG) procedure involves connecting the patient to a heart-lung bypass machine which performs the function of the heart and lungs. The patient’s heart is then stopped with medication and the grafting process begins. Once the procedure is completed, the patient’s heart is restarted and the heart-lung machine is disconnected.

Who will need a coronary artery bypass surgery?

Coronary artery bypass grafting (CABG) is an established operation that is usually recommended to patients with coronary artery blockages to relieve the symptoms of coronary artery disease:

These symptoms include:
  • Chest discomfort (called angina pectoris), often described as ‘tight’, sometimes involving the jaw, left shoulder or arm. 
  • Pain in the neck, jaw, throat, upper abdomen or back.
  • Breathlessness on exertion or when lying down. 
  • Heart attack during which you may even be breathless, sweaty with cold and clammy peripheries.

However, it is important to note that some patients (especially diabetics) may have absolutely no pain. If a heart attack occurs, CABG can also be performed as an emergency procedure to restore blood flow to the heart. If blood flow is not restored to the affected area, the heart muscles die and become scarred causing the heart to fail as an efficient pump.

Possible complications of CABG 

Coronary artery bypass grafting (CABG) is considered a major surgery and in some cases might result in certain complications, including:
  • Infection: The incision sites can become infected. This can be treated effectively with antibiotics and special dressings. 
  • Bleeding: This is a complication that is often seen in major surgeries.
  • Irregular heartbeat: Arrhythmia can occur after a CABG though it is usually quickly treated with medication.
  • Kidney problems: Some patients might develop kidney problems after a CABG but this is often temporary.
  • Heart attack: Some patients might suffer a heart attack during or after the surgery. 

Other CABG techniques 

There are several other ways the CABG can be performed.

1) Off-pump surgery 

The heart is stabilised at various parts, allowing the surgeon to proceed with the surgery while the heart is still beating. This technique reduces the risks of certain complications during or after the surgery. However, this technique is more challenging than the conventional on-pump procedure and is performed in selected patients. 

2) Minimally invasive CABG methods 

Minimally invasive CABG (also known as a keyhole surgery) is where small incisions are made, allowing surgical instruments to be inserted into the body. This technique could also involve the use of robotics and a video feed. Such procedures often lead to quicker recovery due to the significantly smaller wound sizes.

Coronary Artery Bypass Grafting (CABG) - Symptoms

Coronary Artery Bypass Grafting (CABG) - How to prevent?

Coronary Artery Bypass Grafting (CABG) - Causes and Risk Factors

Coronary Artery Bypass Grafting (CABG) - Diagnosis

Coronary Artery Bypass Grafting (CABG) - Treatments

Coronary Artery Bypass Grafting (CABG) - Preparing for surgery

Coronary Artery Bypass Grafting (CABG) - Post-surgery care

Recovering from heart surgery

Coronary artery bypass surgery (CABG) aims to return patients to gainful employment, or active retirement with a restored sense of well-being. Generally, most people will see improvements in their symptoms such as chest pain and breathlessness after CABG. However, you should adopt positive lifestyle changes to sustain these improvements. You must comply with your prescribed medication, stop smoking, control your weight and adhere to a diet low in salt, fat and cholesterol. 

Patients recovering from heart surgeries such as CABG should take note of the following for quicker recovery:

1) Engage in light physical activity

You can start with light activities such as doing chores and taking strolls. This can be beneficial to patients who face difficulties with sleeping after the surgery. However, within the first two months, you should avoid:

  • Lifting, pushing or pulling heavy objects (depending on your level of fitness)
  • Driving a car  
If it is possible, patients going back to work should start with reduced working hours and workloads before gradually increasing these back to normal. This prevents excessive strain on the body.

2) Care for your wound(s)

Keep the wounds and the surrounding areas dry. Clean the wound using soap and warm water only. Please visit your doctor immediately if you notice any signs of infection such as:
  • Pus 
  • Fever more than 38º C
  • Tenderness and redness around the wound 
  • Opening up of the wound

3) Take note of cognitive and emotional changes

Patients might experience slight decreases in their cognitive functions though this is usually temporary. To cope with this, patients should avoid any stressful or mentally taxing tasks within the first few weeks of surgery. 

Some patients might also experience an onset of low moods or even depression after the surgery. However, patients’ moods should generally improve over the period of recovery. Patients could also speak with their family and friends to cope with these emotions. 

Cardiovascular Rehabilitation & Preventive Cardiology (CVR & PC) Programme

You are encouraged to attend the Cardiovascular Rehabilitation & Preventive Cardiology Programme that will enable, encourage and assist you on the road to recovery.

Cardiovascular rehabilitation is a process to enable, encourage and assist you to make the transition from a state of illness back to a state of health and normal function. It is a lifelong process and begins from the time of diagnosis. The four basic features of the programme are behavioural counselling, aggressive risk factor modification, health education and exercise training.

Various members of the health team will be available to teach, guide and encourage you. The team comprises of physicians, nurses, physiotherapists, psychiatrist, dietitians and pharmacists. But the effort to achieve the goal of optimal rehabilitation depends solely on you.

Cardiac Rehab Programme


  • Updated on 2022-08-31T16:00:00Z