What Is Coronary Artery Bypass Surgery?

Reviewed by James Beckerman, MD, FACC on August 24, 2020

If your doctor tells you that you need a coronary artery bypass operation on your heart, you’ve probably got a lot of questions.

Your coronary arteries supply your heart muscle with blood. If they have too much plaque built up in them, it can narrow or even block your blood from passing through. If your heart can’t get enough blood or oxygen, you can have a heart attack.

If your coronary arteries are dangerously blocked, your doctor may recommend an operation to get around, or “bypass” the blockage. It’s like taking an alternate route when your usual ride home is clogged up by traffic. The operation builds that bypass.

You’ll still need a healthy diet, exercise, and probably medicine to prevent another blockage. But first, you’ll want to know what to expect from the surgery, how to prepare, what complications can happen, and what the recovery is like.

Why Do I Need It?

You may have already tried other things that didn’t help enough. For instance, you may have gotten stents, which opened the blockages.

If that didn’t help (along with diet, exercise, and prescription medicines), or if you developed new blockages, that’s when you may need to see a cardiothoracic surgeon about a bypass.

How to Prepare

Before your surgery, you’ll get blood tests, chest X-rays, and an electrocardiogram (EKG). Your doctor may also do an X-ray procedure called a coronary angiogram. It uses a special dye to show how the blood moves through your arteries.

Your doctor will also let you know if you need to make any changes to your diet or lifestyle before the surgery and make any changes to medicines you take. Also tell your doctor about any vitamins and supplements you take, even if they are natural, in case they could affect your risk of bleeding.

You’ll also need to make plans for recovery after your surgery.


During the Surgery

The operation itself usually takes 3 to 6 hours. You’ll get general anesthesia, which means you won’t be awake.


If you get open-heart surgery, the surgeon will make a long cut in the center of your chest and open your rib cage. They may temporarily stop your heart to keep it still during the procedure. Your blood will keep circulating through your body with the help of a heart-lung machine (“on-pump”).


Then the surgeon will build your “bypass.” First, they’ll remove a healthy artery from your chest or wrist, or a vein from your leg. This is called a “graft.” Then, they’ll attach that artery above and below the one that is blocked.

When your surgery is complete, blood will flow to your heart through your new graft. You could need several grafts during the same surgery. For instance, if you get three grafts, that’s a “triple bypass.”

In some cases, the surgeon may not need to stop your heart. These are called “off-pump” procedures. Others only need tiny cuts. These are called “keyhole” procedures.

Finally, some surgeries rely on the help of robotic devices. Your surgeon will recommend the best operation for you.

What are the Risks?

Every surgery comes with risks, and coronary artery bypass surgery is no different. Some of those include:

  • Blood clots that can increase your chances of having a stroke, heart attack, or lung problems
  • Bleeding
  • Infection
  • Abnormal heart rhythms (arrhythmias)
  • Pneumonia
  • Problems breathing
  • Fever and pain
  • Kidney failure
  • Memory loss and trouble thinking clearly

Many things affect these risks, including your age, how many bypasses you get, and any other medical conditions you may have. You and your surgeon will discuss these before your operation.

What to Expect After Surgery

When you wake up from the surgery, you may feel groggy. During the procedure, the medical team will likely place a thin tube called a catheter in your bladder to collect urine. When you’re able to get up and use the bathroom on your own, they’ll remove it.

They’ll also attach an IV line before the surgery so you can receive fluids and medications. You’ll get it removed once you’re able to eat and drink on your own and no longer need IV medications.


After the surgery, you will need to spend a day or two in the intensive care unit so doctors can make sure your heart and breathing are fine.

Fluids will build up around your heart after the procedure, so your doctor will insert tubes in your chest. They’ll be there for 1 to 3 days after surgery to allow the fluid to drain.

You may feel soreness in your chest. You’ll have the most discomfort in the first 2 to 3 days following the procedure. You will likely get pain medicines for that.

You should be able to start walking 1 to 2 days after surgery, and you will likely move out of the intensive care unit into a transitional care unit after about 12 or 24 hours.

When You Can Go Home

You may be able to leave the hospital after 4 or 5 days. But this will depend on how fast you recover and whether you have any other problems.

You might not be hungry and even be constipated for a few weeks after the surgery. You could have trouble sleeping while you’re in the hospital. If the surgeon removes a piece of healthy vein from your leg, you may have some swelling there. This is all normal.

If you work at a desk job and you don’t have any complications from the surgery, you can probably go back to work 4 to 6 weeks after your surgery. If your job involves more physical activity, you may need extra recovery time at home.

It will likely take about 2 to 3 months for you to completely heal.

Your doctor should talk with you about what changes you’ll need to make to help prevent another blockage. This may include:

  • Not smoking
  • Taking medicines that lower “bad” (LDL) cholesterol
  • Becoming more active
  • Maintaining a healthy weight
  • Cutting back on saturated fat (unhealthy fats)
  • Adding more vegetables, whole grains, and fruits to your diet
  • Participating in a supervised cardiac rehab (exercise, heart-healthy education, counseling, and stress reduction)
WebMD Medical Reference



National Institute of Health: “What is Coronary Artery Bypass Grafting?”

National Institute of Health: “What is Cardia Rehabilitation?”

MedlinePlus: “Coronary Artery Disease”

Mayo Clinic: “Coronary Bypass Surgery”

Cleveland Clinic: “Coronary Artery Bypass Surgery”

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