Purpose of Triple Bypass Surgery

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Triple bypass surgery, a type of coronary artery bypass grafting (CABG), is an open-heart procedure that is done to treat three blocked or partially blocked coronary arteries in the heart. Each of the operative vessels is individually bypassed so it can deliver blood to the heart muscle.

You may need to have this surgery if you have coronary artery disease (CAD) due to atherosclerosis that prevents blood from flowing freely.

Triple bypass surgery does not cure or prevent CAD, but it can prevent CAD symptoms such as chest pain and shortness of breath. Furthermore, it can improve overall heart function, improve quality of life, and reduce the risk of death.

Blood vessels are taken from your leg (saphenous vein), inside your chest (internal mammary artery), or your arm (radial artery) to replace the diseased portions of coronary arteries. The specific vessel used will be determined by your surgeon.

Heart surgeons during a heart operation - stock photo

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Diagnosis Related to Triple Bypass Surgery

CAD due to atherosclerosis is the most common reason for triple bypass surgery. Atherosclerosis, also known as “hardening of the arteries,” occurs when cholesterol and other lipids begin to accumulate on the inner walls of damaged blood vessels. This buildup leads to the formation of a waxy thickening in the vessel, known as a plaque.

Atherosclerosis can develop in any blood vessel in the body, and when it affects arteries in the heart, it can lead to a heart attack.

The AMA Journal of Ethics considers angina pectoris, which is chest pain due to diminished blood flow in the coronary arteries, a potential indication for triple bypass surgery.

The American Heart Association identifies the following benefits for bypass surgery:

  • Manage blockage of blood flow to the heart muscles
  • Improve the supply of blood and oxygen to the heart muscles
  • Reduce the risk of heart attack
  • Improve the ability to maintain physical activity that has been limited by angina or ischemia (insufficient blood supply)

How Common Is Bypass Surgery?

Bypass surgery is the most common cardiothoracic surgical procedure. A 2020 market report places the number at 340,000 CABG surgeries per year in the U.S.


The American Heart Association (AHA), in conjunction with the American College of Cardiology, developed recommendations for bypass surgery.

These criteria, last updated in 2011, include several patient subgroups:

Patients who may need emergency bypass surgery with an acute MI (heart attack) include:

  • Patients with acute MI in whom
  • 1) primary PCI has failed or cannot be performed
  • 2) coronary anatomy is suitable for CABG, and
  • 3) persistent ischemia of a significant area of the myocardium (heart muscle) at rest and/or hemodynamic instability refractory to nonsurgical therapy is present
  • Patients undergoing surgical repair of a postinfarction mechanical complication of MI, such as ventricular septal rupture, mitral valve insufficiency due to papillary muscle infarction and/or rupture, or free wall rupture
  • Patients with cardiogenic shock and who are suitable for CABG irrespective of the time interval from MI to onset of shock and time from MI to CABG
  • Patients with life-threatening ventricular arrhythmias (believed to be ischemic in origin) in the presence of left main artery stenosis (narrowing) greater than or equal to 50% and/or three-vessel coronary artery disease (CAD)
  • Patients with multivessel CAD with recurrent angina or MI within the first 48 hours of ST-elevation myocardial infarction (STEMI) presentation as an alternative to a more delayed strategy
  • Patients older than 75 years of age with ST-segment elevation or left bundle branch block who are suitable for revascularization irrespective of the time interval from MI to the onset of shock

The guidelines also list times when emergency CABG is not indicated:

  • Emergency CABG should not be performed in patients with persistent angina and a small area of viable myocardium who are thermodynamically stable.
  • Emergency CABG should not be performed in patients with no-reflow (successful epicardial reperfusion with unsuccessful microvascular reperfusion).

Tests and Labs

Prior to having triple bypass surgery, you can expect to have a series of tests and procedures to determine if this type of surgery is the best option for you.

These tests may include:

  • Stress test: This is a cardiac perfusion scan that measures the amount of blood in your heart muscle at rest and during exercise. You would walk and/or run on a treadmill for this test.
  • Echocardiogram: This test uses an ultrasound to create a picture of the heart while it is moving and to assess the blood flow in and out of the heart.
  • Electrocardiogram (ECG or EKG): This study measures the electrical activity of the heart.
  • Cardiac catheterization: This is an invasive test that examines specific blockages of the coronary blood vessels, using dye and special X-rays to show the insides of the coronary arteries.
  • Pulmonary function test: This test involves your participation. It measures how well your lungs take in and release air and how well they move gases such as oxygen.
  • Blood work: These labs may include complete blood count, chemistry, and coagulation studies.
  • Chest X-ray: This will look at the chest, lungs, heart, large arteries, ribs, and diaphragm.
  • Cardiac magnetic resonance imaging (MRI): This provides a detailed picture of the heart, including chambers and surrounding blood vessels
  • Carotid Doppler/ultrasound study: The purpose of carotid ultrasound is to screen for blockage or narrowing of the carotid arteries, which may increase the risk of having a stroke.
  • Transesophageal echocardiogram (TEE): This is an invasive test that looks at the heart valves and chambers and how the heart is functioning.
  • Computed tomography scan (CT): This test assesses the structure of the aorta, lungs, and surrounding organs.
  • Ankle-brachial index: This test determines if there are any blockages or narrowing of the arteries in the arms and legs.
  • Vein mapping: This is a non-invasive test that examines the blood vessels in the legs.

Depending on the severity of the heart disease or pain, you may have one or more of the above tests. If you are having an emergency triple bypass, you would not be able to have a time-consuming test, such as a stress test.

A Word From Verywell

Because triple bypass surgery involves three major blood vessels, it has considerable risks. You may have this surgery as a scheduled procedure, but in some circumstances, it may be done as an emergency operation.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Reenan J. Indications for bypass surgery. AMA Journal of Ethics.

  2. American Heart Association. Cardiac procedures and surgeries.

  3. iData Research. New study shows approximately 340,000 CABG procedures per year in the United States.

  4. Hillis LD, Smith PK, Anderson JL, et. al. 2011 ACCF/AHA guideline for coronary artery bypass graft surgery: Executive summary: A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2011 Dec 6;124(23):2610-42. doi:10.1161/CIR.0b013e31823b5fee. Erratum in: Circulation. 2011 Dec 20;124(25):e956. Erratum in: Circulation. 2012 Aug 14;126(7):e105

By Kathleen Gaines, MSN, RN, CBC
Kathleen Gaines, MSN, RN, CBC, is a nurse and health journalist, as well as an adjunct clinical faculty member at hospitals in the Philadelphia area.