A coronary artery bypass graft (CABG) involves restoring blood flow to the heart. The procedure is an option for a person if their arteries become blocked. Undergoing a CABG may decrease the risk of a heart attack.

Depending on the extent of the blockage, doctors may consider alternative treatments to help open a blocked artery. These treatments include medications or other medical procedures.

The article below provides more information on the CABG procedure, including the risks, recovery, and alternatives to a bypass.

A doctor preparing a patient for surgeryShare on Pinterest
Protonic Ltd/Stocksy

A CABG redirects the blood flow around a blocked artery to the heart. Typically, arteries become blocked due to heart disease or atherosclerosis. When an artery becomes blocked, it reduces blood flow to the heart, leading to a heart attack or weakening of the heart muscle.

The surgery involves taking a vessel from the arm, leg, or inside the chest and attaching it above or below the blocked artery. The procedure creates a new route and redirects blood circulation to the heart.

More than one vessel may need grafting, depending on the number of blocked arteries or portions of blocked arteries. For example:

  • A double bypass involves grafting two arteries.
  • A triple bypass involves three arteries.
  • A quadruple bypass involves four arteries.
  • A quintuple bypass involves five arteries.

A CABG is the most commonly performed heart surgery in the United States. There are about 200,000 procedures performed every year.

Individuals with certain cardiac conditions may benefit from a CABG. For example, people with coronary artery disease may develop a blockage in an artery to their heart. The blockage occurs due to a buildup of plaque inside the arteries. If the blockage becomes severe enough, it can lead to a heart attack or cardiac arrest.

People with blockages that are not treatable with other procedures or medications, or those who benefit from bypass surgery (such as diabetics), may need a coronary artery bypass to reduce their risk of a life threatening cardiac event.

Although a coronary artery bypass is usually lifesaving, it can have potential risks. Problems may develop during the procedure or the recovery stage.

Possible risks include:

  • abnormal heart rhythm
  • brain-related problems such as a stroke
  • infected wounds from the graft
  • reduced kidney function

Research suggests that postoperative complications of CABG surgery have resulted in significant morbidity and mortality rates.

Risk factors

The prognosis after a CABG may vary based on age, the severity of heart disease, and other underlying medical conditions. These factors may increase a person’s risk of developing complications.

Other factors include:

The surgical team will provide a person with more detailed information about any specific risks before surgery.

In some cases, CABG surgery occurs in an emergency.

However, in other non-emergency instances, an individual has a few preoperative appointments before the procedure. An individual may have several tests to confirm they are a good candidate for the surgery.

Preoperative tests may include:

  • an electrocardiogram
  • blood tests
  • chest X-ray
  • an angiogram to check for blockages
  • a venogram to assess veins in the legs
  • echocardiogram to assess the heart’s pumping function

The first step involves removing and preparing a vein or artery from another location, such as the arm or leg.

The surgeon makes a cut down the chest and through the breast bone to view the coronary arteries and heart. The surgeon then creates a pathway for blood flow with the new vessel.

CABG surgery is performed either on or off-pump, which involves the following:


An on-pump procedure involves placing a person on a heart-lung machine. The machine takes over the function of the heart and keeps blood moving throughout the body. This allows the doctor to operate on a still heart. After the procedure, the surgeon restarts the heart and turns off the pump.


The surgery includes the same procedure as above except without using a heart-lung machine. The heart pumps blood throughout the body and moves throughout the surgery.

Some doctors may also use a minimally invasive CABG procedure. This surgery involves making small incisions instead of large cuts and does not use a pump.

Whether a doctor performs the surgery on or off-pump may depend on how many vessels require grafting and how complicated the anatomy is. Some studies show that a CABG off-pump may have some advantages.

A study in theJournal of Cardiac Surgery analyzed cases from 414 patients with a previous stroke or transient ischemic attack history. Of the patients, 29% had off-pump CABG, and 71% had an on-pump CABG.

The study found that people that had the surgery off-pump had a decreased risk of complications, such as postoperative delirium and stroke.

However, further research is required to conclude which method is more effective and poses less risk to patients.

Length of hospital stay and recovery may vary depending on whether complications occur.

Typically, patients move from the operating room to the intensive care unit right after surgery to monitor a person’s condition. Patients may remain on a ventilator to help them breathe for a few hours after the procedure. A chest tube drains fluid from the chest. The medical team frequently monitors vital signs, such as heart rate, blood pressure, and respiratory rate.

Once the monitoring interval decreases, usually, the patient moves to a step-down unit.

A person is usually transferred to this unit when:

  • Doctors have removed the breathing tube.
  • A person is able to switch from intravenous to oral medicines.
  • Doctors reduce invasive tubes and monitoring.
  • No medications are needed to support blood pressure.

A person might see a physical therapist during their hospital stay and start getting out of bed, walking, and practicing deep breathing exercises.

After arriving home, people learn to watch for signs of an infection or other complications. They will need to keep the graft wounds clean.

A person may also continue to take pain relievers to ease any soreness from surgical incisions. Wearing loose clothing can also help.

Doctors may recommend attending cardiac rehabilitation classes. Cardiac rehabilitation includes a structured education and exercise program to increase activity level gradually.

Instead of having a CABG procedure, additional options exist to treat blocked arteries. Options for other treatment may depend on the extent of the blockage.

Alternative treatment includes the following:


Medications may help decrease the risk of complications from a blocked artery, such as a heart attack, stroke, or heart failure. Prescription drugs may also help lower cholesterol levels and reduce the risk of worsening blockages.

Medications may include the following:

  • statins, which help lower high cholesterol levels
  • beta-blockers, which treat high blood pressure and help ease chest pain
  • antiplatelets, which help prevent blood clots from developing and decrease the risk of a heart attack

Percutaneous coronary intervention (PCI)

A PCI helps open a blocked artery. The procedure uses a catheter inserted into a blood vessel in the arm or groin. The doctor threads the catheter up to the blocked artery using a guided X-ray. Next, the physician inflates a balloon attached to the catheter and places a small stent to keep the artery open.

Overall, PCI is a safe procedure without complications.

Learn more about the rare complications associated with PCI.

In general, doctors prefer CABG over PCI or medical management for certain types of people, such as people with diabetes or those with left main or triple-vessel disease.

A CABG helps treat a blocked artery to the heart. In some cases, the procedure may involve placing a person on a pump, which takes over the heart’s function and moves blood through the body.

The procedure is useful for people with coronary artery disease that have blocked arteries. The complications and recovery from a coronary artery bypass vary depending on a person’s age, medical history, and the complexity of the surgery.

Doctors may consider alternatives to a CABG, including medications and PCI, based on the extent of the blockage. However, doctors prefer a CABG for certain types of patients.