Bypass surgery-also called coronary artery bypass graft surgery-helps improve blood flow to the heart in people with severe coronary artery disease .

In most cases, bypass surgery is open-chest surgery. The surgeon connects, or grafts, a healthy blood vessel from another part of your body to the narrowed coronary artery. The grafted blood vessel goes around (bypasses) the narrowed part of the artery. This makes a new path for blood to your heart muscle.

Most people have bypasses in two or more arteries. How many you need depends on how many arteries, and which ones, are narrowed.

Bypass surgery is not a cure for heart disease. The surgery doesn't change the way arteries harden or narrow because of heart disease. And it doesn't bypass all the narrowing that you may have in your arteries.

Even after surgery, you can still get new places in your arteries that are narrowed. This can happen in the new blood vessels used in the bypass, as well as in the other arteries. If this happens, you may need another surgery or angioplasty with stents . That's why after surgery you still need medicines and lifestyle changes to give you the best chance of living a longer, healthier life.

Recovery after surgery

You will stay in the hospital at least 3 to 8 days after the surgery. You will probably be able to do many of your usual activities after 4 to 6 weeks. Most people are able to go back to work 1 to 2 months after surgery.

Lifestyle changes and medicines

You can do things after surgery to help yourself stay healthy and prevent problems. Medicines and a healthy lifestyle-known as medical therapy-can help your bypass grafts last and stay open longer. Medical therapy also can lower your risk of a heart attack or stroke.

You will likely take medicines to prevent blood clots, lower cholesterol, and manage blood pressure. You may need to make lifestyle changes. These include eating right, being active, and not smoking. It also means losing weight or staying at a healthy weight. A cardiac rehab program can help you make these changes.

Surgery isn't right for everyone. Some people can be helped by angioplasty along with medicines and lifestyle changes (medical therapy). Others use medical therapy alone.

• Angioplasty with stents , along with medicines and lifestyle changes. Angioplasty is done through a blood vessel, so it is less invasive than surgery. The procedure has fewer risks for some people. Recovery is quicker than with surgery. After angioplasty with stents, most people take medicine to reduce the risk of blood clots. You may take this medicine for at least 1 year.
• Medical therapy alone. You need to take medicines and make lifestyle changes with any treatment that you choose. But medical therapy alone may be a choice for you if your angina is not affecting your quality of life. The medicines help prevent blood clots, lower cholesterol, and manage blood pressure. Lifestyle changes include eating healthy foods, being physically active, staying at a healthy weight, and not smoking.

One of these treatments may be an option for you. It depends on your age, your other health problems, and how severe your heart disease is. It also depends on what you want. You and your doctor can decide together whether bypass surgery or another treatment is right for you.

You may have several tests to see if a bypass could help you. You may have had an angiogram that showed your doctor the location and amount of narrowing in your arteries. Your doctor also may have checked how well your heart is pumping blood.

Whether a bypass is an option for you depends on several things. These include which coronary arteries are narrowed, your age, and other health problems that you may have. It also depends on how much your angina keeps you from doing your daily activities and enjoying your life.

Your doctor may recommend surgery if:

• Your left main heart artery is very narrow.
• The three larger arteries of the heart are narrowed.
• You have diabetes, and two or more of the larger arteries are narrowed.
• The benefits of surgery for you are greater than the risks.

As you decide about surgery, think about what is most important to you. Talk to your doctor about what you hope surgery could do to improve your symptoms or lengthen your life. The benefits of surgery may or may not outweigh the risks for you.

Bypass surgery can:

• Relieve angina symptoms and improve quality of life. You may be able to do more of your daily activities. ^{footnote 1}
• Help some people live longer. Whether it could help you live longer depends on several things. These include your overall health and which arteries need to be bypassed. For example, the surgery may raise your chances of living longer if you have diabetes and narrowing in your heart's larger arteries. ^{footnote 2 , footnote 3}

Bypass surgery has been done for more than 40 years. In the United States, it is one of the most common major surgeries. But it has some risks.

The chances of having a serious problem with bypass surgery increase with age. Your risk is also higher if you have other problems such as diabetes, kidney disease, lung disease, or peripheral arterial disease. Your doctor can help you understand what your risk for problems is.

The risks during or soon after bypass surgery include:

• Infection.
• Kidney problems.
• Atrial fibrillation .
• Heart attack.
• Stroke.
• Short-term problems with thinking and memory. This is more common in older people. It tends to get better within several months of surgery.
• Death.

Benefits

Angina relief: In studies, about 84 out of 100 people who had bypass surgery had angina relief after 1 year. This relief lasted at least 5 years.* (Some of these people had another procedure that could have added to their angina relief.) ^{footnote 1}

*Based on the best available evidence (evidence quality: moderate )

Living longer: Bypass can help some people live longer. How well bypass might help you live longer depends on several things, including which coronary arteries need to be bypassed and how bad your heart disease is. It also can depend on other conditions that you have, such as diabetes.

Number of people alive 5 and 10 years after bypass surgery* ^{footnote 4}

	After 5 years	After 10 years
Bypass surgery plus medical therapy	About 90 out of 100 are alive; about 10 out of 100 aren't.	About 73 out of 100 are alive; about 27 out of 100 aren't.
Medical therapy alone	About 84 out of 100 are alive; about 16 out of 100 aren't.	About 69 out of 100 are alive; about 31 aren't.

*Based on the best available evidence (evidence quality: moderate )

Understanding the evidence

Some evidence is better than other evidence. Evidence comes from studies that look at how well treatments and tests work and how safe they are. For many reasons, some studies are more reliable than others. The better the evidence is-the higher its quality-the more we can trust it.

The information shown here is based on the best available evidence. The evidence is rated using four quality levels: high, moderate, borderline, and inconclusive .

Another thing to understand is that the evidence can't predict what's going to happen in your case. When evidence tells us that 2 out of 100 people who have a certain test or treatment may have a certain result and that 98 out of 100 may not, there's no way to know if you will be one of the 2 or one of the 98.

Risks

Take 100 people who have bypass surgery . Complication rates in hospitals show people face these risks from bypass surgery:

• Stroke: About 1 to 4 out of 100 people have a stroke during or soon after surgery. That means that about 96 to 99 people out of 100 don't have a stroke. ^{footnote 5 , footnote 6} Some risk factors can increase your risk for stroke. These include older age, diabetes, and high blood pressure. Talk to your doctor about your own risk.
• Deep infection of the incision: About 1 out of 100 people have a deep infection in the chest incision. This means that about 99 out of 100 don't have this problem. ^{footnote 5}
• Kidney problems: About 2 to 6 out of 100 people have kidney problems. So about 94 to 98 people out of 100 don't have kidney problems. ^{footnote 5}
• Death: About 1 to 5 out of 100 people die during or soon after surgery. About 95 to 99 people out of 100 survive the surgery. ^{footnote 5}