Coronary Heart Diseases
26.04.2019

Coronary heart disease (CHD) is a disease in which a waxy substance called plaque (plak) builds up inside the coronary arteries. These arteries supply oxygen-rich blood to your heart musce.

When plaque builds up in the arteries, the condition is called atherosclerosis. The buildup of plaque occurs over many years.

Over time, plaque can harden or rupture (break open). Hardened plaque narrows the coronary arteries and reduces the flow of oxygen-rich blood to the heart.

If the plaque ruptures, a blood clot can form on its surface. A large blood clot can mostly or completely block blood flow through a coronary artery. Over time, ruptured plaque also hardens and narrows the coronary arteries.

Overview

If the flow of oxygen-rich blood to your heart muscle is reduced or blocked, angina(an-JI-nuh or AN-juh-nuh) or a heart attack can occur.

Angina is chest pain or discomfort. It may feel like pressure or squeezing in your chest. The pain also can occur in your shoulders, arms, neck, jaw, or back. Angina pain may even feel like indigestion.

A heart attack occurs if the flow of oxygen-rich blood to a section of heart muscle is cut off. If blood flow isn’t restored quickly, the section of heart muscle begins to die. Without quick treatment, a heart attack can lead to serious health problems or death.

Over time, CHD can weaken the heart muscle and lead to heart failure andarrhythmias (ah-RITH-me-ahs). Heart failure is a condition in which your heart can’t pump enough blood to meet your body’s needs. Arrhythmias are problems with the rate or rhythm of the heartbeat.

Outlook

CHD is the most common type of heart disease. In the United States, CHD is the #1 cause of death for both men and women. Lifestyle changes, medicines, and medical procedures can help prevent or treat CHD. These treatments may reduce the risk of related health problems.
Causes

Research suggests that coronary heart disease (CHD) starts when certain factors damage the inner layers of the coronary arteries. These factors include:

  • Smoking
  • High levels of certain fats and cholesterol in the blood
  • High blood pressure
  • High levels of sugar in the blood due to insulin resistance or diabetes
  • Blood vessel inflammation

Plaque might begin to build up where the arteries are damaged. The buildup of plaque in the coronary arteries may start in childhood.

Over time, plaque can harden or rupture (break open). Hardened plaque narrows the coronary arteries and reduces the flow of oxygen-rich blood to the heart. This can cause angina (chest pain or discomfort).

If the plaque ruptures, blood cell fragments called platelets (PLATE-lets) stick to the site of the injury. They may clump together to form blood clots.

Blood clots can further narrow the coronary arteries and worsen angina. If a clot becomes large enough, it can mostly or completely block a coronary artery and cause a heart attack.

n the United States, coronary heart disease (CHD) is the #1 cause of death for both men and women. Each year, more than 400,000 Americans die from CHD.

Certain traits, conditions, or habits may raise your risk for CHD. The more risk factors you have, the more likely you are to develop the disease.

You can control many risk factors, which may help prevent or delay CHD.
Major Risk Factors

  • Unhealthy blood cholesterol levels. This includes high LDL cholesterol (sometimes called “bad” cholesterol) and low HDL cholesterol (sometimes called “good” cholesterol).
  • High blood pressure. Blood pressure is considered high if it stays at or above 140/90 mmHg over time. If you have diabetes or chronic kidney disease, high blood pressure is defined as 130/80 mmHg or higher. (The mmHg is millimeters of mercury—the units used to measure blood pressure.)
  • Smoking. Smoking can damage and tighten blood vessels, lead to unhealthy cholesterol levels, and raise blood pressure. Smoking also can limit how much oxygen reaches the body’s tissues.
  • Insulin resistance. This condition occurs if the body can’t use its own insulin properly. Insulin is a hormone that helps move blood sugar into cells where it’s used for energy. Insulin resistance may lead to diabetes.
  • Diabetes. With this disease, the body’s blood sugar level is too high because the body doesn’t make enough insulin or doesn’t use its insulin properly.
  • Overweight or obesity. The terms “overweight” and “obesity” refer to body weight that’s greater than what is considered healthy for a certain height.
  • Metabolic syndrome. Metabolic syndrome is the name for a group of risk factors that raises your risk for CHD and other health problems, such as diabetes and stroke.
  • Lack of physical activity. Being physically inactive can worsen other risk factors for CHD, such as unhealthy blood cholesterol levels, high blood pressure, diabetes, and overweight or obesity.
  • Unhealthy diet. An unhealthy diet can raise your risk for CHD. Foods that are high in saturated and trans fats, cholesterol, sodium (salt), and sugar can worsen other risk factors for CHD.
  • Older age. Genetic or lifestyle factors cause plaque to build up in your arteries as you age. By the time you’re middle-aged or older, enough plaque has built up to cause signs or symptoms. In men, the risk for CHD increases after age 45. In women, the risk for CHD increases after age 55.
  • Family history of early heart disease. Your risk increases if your father or a brother was diagnosed with CHD before 55 years of age, or if your mother or a sister was diagnosed with CHD before 65 years of age.

Although older age and a family history of early heart disease are risk factors, it doesn’t mean that you’ll develop CHD if you have one or both. Controlling other risk factors often can lessen genetic influences and help prevent CHD, even in older adults.

Emerging Risk Factors

Researchers continue to study other possible risk factors for CHD.

High levels of a protein called C-reactive protein (CRP) in the blood may raise the risk of CHD and heart attack. High levels of CRP are a sign of inflammation in the body.

Inflammation is the body’s response to injury or infection. Damage to the arteries’ inner walls may trigger inflammation and help plaque grow.

Research is under way to find out whether reducing inflammation and lowering CRP levels also can reduce the risk of CHD and heart attack.

High levels of triglycerides (tri-GLIH-seh-rides) in the blood also may raise the risk of CHD, especially in women. Triglycerides are a type of fat.

Other Risks Related to Coronary Heart Disease

Other conditions and factors also may contribute to CHD, including:

  • Sleep apnea. Sleep apnea is a common disorder in which you have one or more pauses in breathing or shallow breaths while you sleep. Untreated sleep apnea can increase your risk for high blood pressure, diabetes, and even a heart attack or stroke.
  • Stress. Research shows that the most commonly reported “trigger” for a heart attack is an emotionally upsetting event, especially one involving anger.
  • Alcohol. Heavy drinking can damage the heart muscle and worsen other CHD risk factors. Men should have no more than two drinks containing alcohol a day. Women should have no more than one drink containing alcohol a day.
  • Preeclampsia (pre-e-KLAMP-se-ah). This condition can occur during pregnancy. The two main signs of preeclampsia are a rise in blood pressure and excess protein in the urine. Preeclampsia is linked to an increased lifetime risk of heart disease, including CHD, heart attack, heart failure, and high blood pressure.

Signs and symptoms

A common symptom of coronary heart disease (CHD) is angina. Angina is chest pain or discomfort that occurs if an area of your heart muscle doesn’t get enough oxygen-rich blood.

Angina may feel like pressure or squeezing in your chest. You also may feel it in your shoulders, arms, neck, jaw, or back. Angina pain may even feel like indigestion. The pain tends to get worse with activity and go away with rest. Emotional stress also can trigger the pain.

Another common symptom of CHD is shortness of breath. This symptom occurs if CHD causes heart failure. When you have heart failure, your heart can’t pump enough blood to meet your body’s needs. Fluid builds up in your lungs, making it hard to breathe.

The severity of these symptoms varies. They may get more severe as the buildup of plaque continues to narrow the coronary arteries.

Some people who have CHD have no signs or symptoms—a condition called silent CHD. The disease might not be diagnosed until a person has signs or symptoms of a heart attack, heart failure, or an arrhythmia (an irregular heartbeat).

Heart Attack

A heart attack occurs if the flow of oxygen-rich blood to a section of heart muscle is cut off. This can happen if an area of plaque in a coronary artery ruptures (breaks open).

Blood cell fragments called platelets stick to the site of the injury and may clump together to form blood clots. If a clot becomes large enough, it can mostly or completely block blood flow through a coronary artery.

If the blockage isn’t treated quickly, the portion of heart muscle fed by the artery begins to die. Healthy heart tissue is replaced with scar tissue. This heart damage may not be obvious, or it may cause severe or long-lasting problems.

The most common heart attack symptom is chest pain or discomfort. Most heart attacks involve discomfort in the center or left side of the chest that often lasts for more than a few minutes or goes away and comes back.

The discomfort can feel like uncomfortable pressure, squeezing, fullness, or pain. The feeling can be mild or severe. Heart attack pain sometimes feels like indigestion or heartburn.

The symptoms of angina can be similar to the symptoms of a heart attack. Angina pain usually lasts for only a few minutes and goes away with rest.

Other common signs and symptoms of a heart attack include:

  • Upper body discomfort in one or both arms, the back, neck, jaw, or upper part of the stomach
  • Shortness of breath, which may occur with or before chest discomfort
  • Nausea (feeling sick to your stomach), vomiting, light-headedness or fainting, or breaking out in a cold sweat
  • Sleep problems, fatigue (tiredness), or lack of energy

Heart Failure

Heart failure is a condition in which your heart can’t pump enough blood to meet your body’s needs. Heart failure doesn’t mean that your heart has stopped or is about to stop working.

The most common signs and symptoms of heart failure are shortness of breath or trouble breathing; fatigue; and swelling in the ankles, feet, legs, stomach, and veins in the neck.

All of these symptoms are the result of fluid buildup in your body. When symptoms start, you may feel tired and short of breath after routine physical effort, like climbing stairs.

Arrhythmia

An arrhythmia is a problem with the rate or rhythm of the heartbeat. When you have an arrhythmia, you may notice that your heart is skipping beats or beating too fast.

Some people describe arrhythmias as a fluttering feeling in the chest. These feelings are called palpitations (pal-pih-TA-shuns).

Some arrhythmias can cause your heart to suddenly stop beating. This condition is called sudden cardiac arrest (SCA). SCA usually causes death if it’s not treated within minutes.

Diagnosis

Your doctor will diagnose coronary heart disease (CHD) based on your medical and family histories, your risk factors for CHD, a physical exam, and the results from tests and procedures.

No single test can diagnose CHD. If your doctor thinks you have CHD, he or she may recommend one or more of the following tests.

EKG (Electrocardiogram)

An EKG is a simple, painless test that detects and records the heart’s electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through the heart.

An EKG can show signs of heart damage due to CHD and signs of a previous or current heart attack.

Stress Testing

During stress testing, you exercise to make your heart work hard and beat fast while heart tests are done. If you can’t exercise, you may be given medicine to raise your heart rate.

When your heart is working hard and beating fast, it needs more blood and oxygen. Plaque-narrowed arteries can’t supply enough oxygen-rich blood to meet your heart’s needs.

A stress test can show possible signs and symptoms of CHD, such as:

  • Abnormal changes in your heart rate or blood pressure
  • Shortness of breath or chest pain
  • Abnormal changes in your heart rhythm or your heart’s electrical activity

If you can’t exercise for as long as what is considered normal for someone your age, your heart may not be getting enough oxygen-rich blood. However, other factors also can prevent you from exercising long enough (for example, lung diseases, anemia, or poor general fitness).

As part of some stress tests, pictures are taken of your heart while you exercise and while you rest. These imaging stress tests can show how well blood is flowing in your heart and how well your heart pumps blood when it beats.
Echocardiography

Echocardiography (echo) uses sound waves to create a moving picture of your heart. The picture shows the size and shape of your heart and how well your heart chambers and valves are working.

Echo also can show areas of poor blood flow to the heart, areas of heart muscle that aren’t contracting normally, and previous injury to the heart muscle caused by poor blood flow.

Chest X Ray

A chest x ray takes pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels.

A chest x ray can reveal signs of heart failure, as well as lung disorders and other causes of symptoms not related to CHD.

Blood Tests

Blood tests check the levels of certain fats, cholesterol, sugar, and proteins in your blood. Abnormal levels might be a sign that you’re at risk for CHD.

Electron-Beam Computed Tomography

Electron-beam computed tomography (EBCT) is a test that looks for specks of calcium (called calcifications) in the walls of the coronary arteries. Calcifications are an early sign of CHD.

The test can show whether you’re at increased risk for a heart attack or other heart problems before other signs and symptoms occur.

EBCT isn’t routinely used to diagnose CHD because its accuracy isn’t yet known.

Coronary Angiography and Cardiac Catheterization

Your doctor may recommend coronary angiography (an-jee-OG-rah-fee) if other tests or factors show that you’re likely to have CHD. This test uses dye and special x rays to show the insides of your coronary arteries.

To get the dye into your coronary arteries, your doctor will use a procedure called cardiac catheterization

A thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. The tube is threaded into your coronary arteries, and the dye is released into your bloodstream.

Special x rays are taken while the dye is flowing through your coronary arteries. The dye lets your doctor study the flow of blood through your heart and blood vessels.

Cardiac catheterization usually is done in a hospital. You’re awake during the procedure. It usually causes little or no pain, although you may feel some soreness in the blood vessel where your doctor inserts the catheter.

Treatments

Treatments for coronary heart disease (CHD) include lifestyle changes, medicines, and medical procedures. Treatment goals may include:

  • Relieving symptoms.
  • Reducing risk factors in an effort to slow, stop, or reverse the buildup of plaque.
  • Lowering the risk of blood clots forming. (Blood clots can cause a heart attack.)
  • Widening or bypassing clogged arteries.
  • Preventing complications of CHD.

Lifestyle Changes

Making lifestyle changes often can help prevent or treat CHD. Lifestyle changes might be the only treatment that some people need.

Follow a Healthy Diet

A healthy diet is an important part of a healthy lifestyle. Following a healthy diet can prevent or reduce high blood pressure and high blood cholesterol and help you maintain a healthy weight.

For information about healthy eating, go to the National Heart, Lung, and Blood Institute’s (NHLBI’s) Aim for a Healthy Weight Web site. This site provides practical tips on healthy eating, physical activity, and controlling your weight.

Therapeutic Lifestyle Changes (TLC). Your doctor may recommend TLC if you have high blood cholesterol. TLC is a three-part program that includes a healthy diet, physical activity, and weight management.

With the TLC diet, less than 7 percent of your daily calories should come from saturated fat. This kind of fat is found in some meats, dairy products, chocolate, baked goods, and deep-fried and processed foods.

No more than 25 to 35 percent of your daily calories should come from all fats, including saturated, trans, monounsaturated, and polyunsaturated fats.

You also should have less than 200 mg a day of cholesterol. The amounts of cholesterol and the types of fat in prepared foods can be found on the foods’ Nutrition Facts labels.

Foods high in soluble fiber also are part of a healthy diet. They help prevent the digestive tract from absorbing cholesterol. These foods include:

  • Whole-grain cereals such as oatmeal and oat bran
  • Fruits such as apples, bananas, oranges, pears, and prunes
  • Legumes such as kidney beans, lentils, chick peas, black-eyed peas, and lima beans

A diet rich in fruits and vegetables can increase important cholesterol-lowering compounds in your diet. These compounds, called plant stanols or sterols, work like soluble fiber.

A healthy diet also includes some types of fish, such as salmon, tuna (canned or fresh), and mackerel. These fish are a good source of omega-3 fatty acids. These acids may help protect the heart from blood clots and inflammation and reduce the risk of heart attack. Try to have about two fish meals every week.

You also should try to limit the amount of sodium (salt) that you eat. This means choosing low-salt and “no added salt” foods and seasonings at the table or while cooking. The Nutrition Facts label on food packaging shows the amount of sodium in the item.

Try to limit drinks that contain alcohol. Too much alcohol will raise your blood pressure and triglyceride level. (Triglycerides are a type of fat found in the blood.) Alcohol also adds extra calories, which will cause weight gain.

Men should have no more than two drinks containing alcohol a day. Women should have no more than one drink containing alcohol a day. One drink is a glass of wine, beer, or a small amount of hard liquor.

Dietary Approaches to Stop Hypertension (DASH). Your doctor may recommend the DASH eating plan if you have high blood pressure. The DASH eating plan focuses on fruits, vegetables, whole grains, and other foods that are heart healthy and low in fat, cholesterol, and sodium.

DASH also focuses on fat-free or low-fat milk and dairy products, fish, poultry, and nuts. The DASH eating plan is reduced in red meats (including lean red meats), sweets, added sugars, and sugar-containing beverages. It’s rich in nutrients, protein, and fiber.

Be Physically Active

Routine physical activity can lower many CHD risk factors, including LDL (“bad”) cholesterol, high blood pressure, and excess weight.

Physical activity also can lower your risk for diabetes and raise your HDL cholesterol level. HDL is the “good” cholesterol that helps prevent CHD.

Talk with your doctor before you start a new exercise plan. Ask him or her how much and what kinds of physical activity are safe for you.

People gain health benefits from as little as 60 minutes of moderate-intensity aerobic activity per week. The more active you are, the more you will benefit.

Maintain a Healthy Weight

Maintaining a healthy weight can lower your risk for CHD. A general goal to aim for is a body mass index (BMI) of less than 25.

BMI measures your weight in relation to your height and gives an estimate of your total body fat.

A BMI between 25 and 29.9 is considered overweight. A BMI of 30 or more is considered obese. A BMI of less than 25 is the goal for preventing and treating CHD. Your doctor or other health care provider can help you set an appropriate BMI goal.

Quit Smoking

If you smoke, quit. Smoking can raise your risk for CHD and heart attack and worsen other CHD risk factors. Talk with your doctor about programs and products that can help you quit smoking. Also, try to avoid secondhand smoke.

If you have trouble quitting smoking on your own, consider joining a support group. Many hospitals, workplaces, and community groups offer classes to help people quit smoking.

Manage Stress

Research shows that the most commonly reported “trigger” for a heart attack is an emotionally upsetting event—particularly one involving anger. Also, some of the ways people cope with stress—such as drinking, smoking, or overeating—aren’t healthy.

Learning how to manage stress, relax, and cope with problems can improve your emotional and physical health. Having supportive people in your life with whom you can share your feelings or concerns can help relieve stress.

Physical activity, medicine, and relaxation therapy also can help relieve stress. You may want to consider taking part in a stress management program.

Medicines

You may need medicines to treat CHD if lifestyle changes aren’t enough. Medicines can:

  • Reduce your heart’s workload and relieve CHD symptoms
  • Decrease your chance of having a heart attack or dying suddenly
  • Lower your cholesterol and blood pressure
  • Prevent blood clots
  • Prevent or delay the need for a procedure or surgery (for example,angioplasty or coronary artery bypass grafting (CABG))

Medicines used to treat CHD include anticoagulants (AN-te-ko-AG-u-lants), also called blood thinners; aspirin and other anticlotting medicines; ACE inhibitors; beta blockers; calcium channel blockers; nitroglycerin; glycoprotein IIb-IIIa; statins; and fish oil and other supplements high in omega-3 fatty acids.

Procedures and Surgery

You may need a procedure or surgery to treat CHD. Both angioplasty and CABG are used to treat blocked coronary arteries. You and your doctor can discuss which treatment is right for you.

Angioplasty

Angioplasty is a nonsurgical procedure that opens blocked or narrowed coronary arteries. This procedure also is called percutaneous (per-ku-TA-ne-us) coronary intervention, or PCI.

A thin, flexible tube with a balloon or other device on the end is threaded through a blood vessel to the narrowed or blocked coronary artery.

Once in place, the balloon is inflated to compress the plaque against the wall of the artery. This restores blood flow through the artery.

During the procedure, the doctor may put a small mesh tube called a stent in the artery. The stent helps prevent blockages in the artery in the months or years after angioplasty.

Coronary angioplasty is done in a special part of the hospital called the cardiac catheterization  laboratory. The “cath lab” has special video screens and x-ray machines.

Your doctor will use this equipment to see enlarged pictures of the blockages in your coronary arteries.

Preparation

In the cath lab, you’ll lie down. An intravenous (IV) line will be placed in your arm to give you fluids and medicines. The medicines will relax you and help prevent blood clots from forming.

The area where your doctor will insert the catheter will be shaved. The catheter usually is inserted in your groin (upper thigh). The shaved area will be cleaned and then numbed. The numbing medicine may sting as it’s going in.

The Procedure

During angioplasty, you’ll be awake but sleepy.

Your doctor will use a needle to make a small hole in an artery in your arm or groin. A thin, flexible guide wire will be inserted into the artery through the small hole. Then, your doctor will remove the needle and place a tapered tube called a sheath over the guide wire and into the artery.

Next, your doctor will put a long, thin, flexible tube called a guiding catheter through the sheath and slide it over the guide wire. The catheter is moved to the opening of a coronary artery, and the guide wire is removed.

Your doctor will inject special dye through the catheter. The dye will help show the inside of the coronary artery and any blockages on an x-ray picture called anangiogram.

Another guide wire is then put through the catheter into the coronary artery and threaded past the blockage. A thin catheter with a balloon at its tip (a balloon catheter) is threaded over the wire and through the guiding catheter.

The balloon catheter is positioned in the blockage. Then, the balloon is inflated. This pushes the plaque against the artery wall, relieving the blockage and improving blood flow through the artery. Sometimes the balloon is inflated and deflated more than once to widen the artery.

Your doctor may put a stent (small mesh tube) in your artery to help keep it open. If so, the stent will be wrapped around the balloon catheter.

When your doctor inflates the balloon, the stent will expand against the wall of the artery. When the balloon is deflated and pulled out of the artery with the catheter, the stent remains in place in the artery.

The animation below shows the process of coronary angioplasty and stent placement. Click the “start” button to play the animation. Written and spoken explanations are provided with each frame. Use the buttons in the lower right corner to pause, restart, or replay the animation, or use the scroll bar below the buttons to move through the frames.

After angioplasty is done, the sheath, guide wires, and catheters are removed from your artery. Pressure is applied to stop bleeding at the catheter insertion site. Sometimes a special device is used to seal the hole in the artery.

During angioplasty, you’ll receive strong antiplatelet medicines through your IV line. These medicines help prevent blood clots from forming in the artery or on the stent. Your doctor may start you on antiplatelet medicines before the angioplasty.

Risks

Coronary angioplasty is a common medical procedure. Serious complications don’t occur often. However, they can happen no matter how careful your doctor is or how well he or she does the procedure.

Angioplasty complications can include:

  • Discomfort and bleeding at the catheter insertion site.
  • Blood vessel damage from the catheters.
  • An allergic reaction to the dye used during the angioplasty.
  • An arrhythmia (irregular heartbeat).
  • The need for emergency coronary artery bypass grafting during the procedure (less than 3 percent of people). This may occur if an artery closes down instead of opening up.
  • Kidney damage caused by the dye used during the angioplasty.
  • Heart attack (3–5 percent of people).
  • Stroke (less than 1 percent of people).

Sometimes chest pain can occur during angioplasty because the balloon briefly blocks blood supply to the heart.

As with any procedure involving the heart, complications can sometimes be fatal. However, this is rare with coronary angioplasty. Less than 2 percent of people die during the procedure.

The risk of complications is higher in:

  • People aged 65 and older
  • People who have chronic kidney disease
  • People who are in shock
  • People who have extensive heart disease and blockages in their coronary (heart) arteries

Research on angioplasty is ongoing to make it safer and more effective and to prevent treated arteries from narrowing again.

Complications From Stents

Restenosis

Another problem that can occur after angioplasty is too much tissue growth within the treated portion of the artery. This can cause the artery to become narrow or blocked again, often within 6 months. This complication is called restenosis (RE-sten-o-sis).When a stent (small mesh tube) isn’t used during angioplasty, 30 percent of people have restenosis. When a stent is used, 15 percent of people have restenosis.

Stents coated with medicine (drug-eluting stents) reduce the growth of scar tissue around the stent. These stents further reduce the risk of restenosis. When these stents are used, about 10 percent of people have restenosis.

Other treatments, such as radiation, can help prevent tissue growth within a stent. For this procedure, a wire is put through a catheter to where the stent is placed. The wire releases radiation to stop any tissue growth that may block the artery.

Blood Clots

Studies suggest that there’s a higher risk of blood clots forming in medicine-coated stents compared with bare metal stents. However, no firm evidence shows that these stents increase the chance of having a heart attack or dying if used as recommended. Researchers continue to study medicine-coated stents.

Taking medicine as prescribed by your doctor can lower your risk of blood clots. People who have medicine-coated stents usually are advised to take antiplatelet medicines, such as clopidogrel and aspirin, for up to a year or longer.

Coronary Artery Bypass Grafting

CABG is a type of surgery. In CABG, arteries or veins from other areas in your body are used to bypass (that is, go around) your narrowed coronary arteries. CABG can improve blood flow to your heart, relieve chest pain, and possibly prevent a heart attack.

CHD is a disease in which a waxy substance called plaque (plak) builds up inside the coronary arteries. These arteries supply oxygen-rich blood to your heart.

Over time, plaque can harden or rupture (break open). Hardened plaque narrows the coronary arteries and reduces the flow of oxygen-rich blood to the heart. This can cause chest pain or discomfort called angina (an-JI-nuh or AN-juh-nuh).

If the plaque ruptures, a blood clot can form on its surface. A large blood clot can mostly or completely block blood flow through a coronary artery. This is the most common cause of a heart attack. Over time, ruptured plaque also hardens and narrows the coronary arteries.

CABG is one treatment for CHD. During CABG, a healthy artery or vein from the body is connected, or grafted, to the blocked coronary artery. The grafted artery or vein bypasses (that is, goes around) the blocked portion of the coronary artery. This creates a new path for oxygen-rich blood to flow to the heart muscle.

Surgeons can bypass multiple coronary arteries during one surgery.

Overview

CABG is the most common type of open-heart surgery in the United States. Doctors called cardiothoracic (KAR-de-o-tho-RAS-ik) surgeons do this surgery.

However, CABG isn’t the only treatment for CHD. Other treatment options include lifestyle changes, medicines, and a procedure called coronary angioplasty (AN-jee-oh-plas-tee).

Angioplasty is a nonsurgical procedure that opens blocked or narrow coronary arteries. During angioplasty, a stent might be placed in a coronary artery to help keep it open. A stent is a small mesh tube that supports the inner artery wall.

CABG or angioplasty may be options if you have severe blockages in your large coronary arteries, especially if your heart’s pumping action has already grown weak. CABG also may be an option if you have blockages in the heart that can’t be treated with angioplasty. In this situation, CABG may work better than other types of treatment.

The goals of CABG may include:

  • Improving your quality of life and reducing angina and other CHD symptoms
  • Allowing you to resume a more active lifestyle
  • Improving the pumping action of your heart if it has been damaged by a heart attack
  • Lowering the risk of a heart attack (in some patients, such as those who have diabetes)
  • Improving your chance of survival

Outlook

The results of CABG usually are excellent. The surgery improves or completely relieves angina symptoms in most patients. Although symptoms can recur, many people remain symptom-free for as long as 10 to 15 years. CABG also may lower your risk of having a heart attack and help you live longer.

You may need repeat surgery if blockages form in the grafted arteries or veins or in arteries that weren’t blocked before. Taking medicines and making lifestyle changes as your doctor recommends can lower the risk of a graft becoming blocked.

There are several types of coronary artery bypass grafting (CABG). Your doctor will recommend the best option for you based on your needs.

Coronary artery bypass grafting (CABG) requires a team of experts. A cardiothoracic surgeon will do the surgery with support from an anesthesiologist, perfusionist (heart-lung bypass machine specialist), other surgeons, and nurses.

There are several types of CABG. They range from traditional surgery to newer, less-invasive methods.

Traditional Coronary Artery Bypass Grafting

For this type of surgery, you’ll be given medicine to help you fall asleep. A doctor will check your heartbeat, blood pressure, oxygen levels, and breathing during the surgery.

A breathing tube will be placed in your lungs through your throat. The tube will connect to a ventilator (a machine that supports breathing).

Your surgeon will make a 6- to 8-inch incision (cut) down the center of your chest wall. Then, he or she will cut your breastbone and open your rib cage to reach your heart.

During the surgery, you’ll receive medicine to thin your blood and keep it from clotting. A heart-lung bypass machine will be connected to your heart. The machine will take over your heart’s pumping action and move blood away from your heart.

A specialist will oversee the heart-lung bypass machine. The machine will allow the surgeon to operate on a heart that isn’t beating and that doesn’t have blood flowing through it.

This type of surgery usually lasts 3–6 hours, depending on the number of arteries being bypassed. Many steps take place during traditional CABG.

You’ll be under general anesthesia (AN-es-THEE-ze-ah) for the surgery. The term “anesthesia” refers to a loss of feeling and awareness. General anesthesia temporarily puts you to sleep.

During the surgery, the anesthesiologist will check your heartbeat, blood pressure, oxygen levels, and breathing. A breathing tube will be placed in your lungs through your throat. The tube will connect to a ventilator (a machine that supports breathing).

The surgeon will make an incision (cut) down the center of your chest. He or she will cut your chest bone and open your rib cage to reach your heart.

You’ll receive medicines to stop your heart. This allows the surgeon to operate on your heart while it’s not beating. You’ll also receive medicines to protect your heart function during the time that it’s not beating.

A heart-lung bypass machine will keep oxygen-rich blood moving throughout your body during the surgery.

The surgeon will take an artery or vein from your body—for example, from your chest or leg—to use as the bypass graft. For surgeries with several bypasses, both artery and vein grafts are commonly used.

  • Artery grafts. These grafts are much less likely than vein grafts to become blocked over time. The left internal mammary artery most often is used for an artery graft. This artery is located inside the chest, close to the heart. Arteries from the arm or other places in the body also are used.
  • Vein grafts. Although veins are commonly used as grafts, they’re more likely than artery grafts to become blocked over time. The saphenous vein—a long vein running along the inner side of the leg—typically is used.

When the surgeon finishes the grafting, he or she will restore blood flow to your heart. Usually, the heart starts beating again on its own. Sometimes mild electric shocks are used to restart the heart.

You’ll be disconnected from the heart-lung bypass machine. Then, tubes will be inserted into your chest to drain fluid.

The surgeon will use wire to close your chest bone (much like how a broken bone is repaired). The wire will stay in your body permanently. After your chest bone heals, it will be as strong as it was before the surgery.

Stitches or staples will be used to close the skin incision. The breathing tube will be removed when you’re able to breathe without it.

The image shows how a heart-lung bypass machine works during surgery.

You’ll be given medicine to stop your heartbeat once you’re connected to the heart-lung bypass machine. A tube will be placed in your heart to drain blood to the machine.

The machine will remove carbon dioxide (a waste product) from your blood, add oxygen to your blood, and then pump the blood back into your body. Your surgeon will insert tubes into your chest to drain fluid.

Once the bypass machine starts to work, the surgeon will repair your heart problem. After the surgery is done, he or she will restore blood flow to your heart. Usually, your heart will start beating again on its own. Sometimes mild electric shocks are used to restart the heart.

Once your heart has started beating again, your surgeon will remove the tubes and stop the heart-lung bypass machine. You’ll be given medicine to allow your blood to clot again.

The surgeon will use wires to close your breastbone. The wires will stay in your body permanently. After your breastbone heals, it will be as strong as it was before the surgery.

Stitches or staples will be used to close the skin incision. Your breathing tube will be removed when you’re able to breathe without it.

Nontraditional Coronary Artery Bypass Grafting

Nontraditional CABG includes off-pump CABG and minimally invasive CABG.

Off-Pump Coronary Artery Bypass Grafting

Instead, your surgeon will steady your heart with a mechanical device so he or she can work on it. Your heart will continue to pump blood to your body.

Off-pump heart surgery is like traditional open-heart surgery because the chest bone is opened to access the heart. However, the heart isn’t stopped, and a heart-lung bypass machine isn’t used.

Surgeons can use off-pump CABG to bypass any of the coronary (heart) arteries. Off-pump CABG is similar to traditional CABG because the chest bone is opened to access the heart.

However, the heart isn’t stopped and a heart-lung-bypass machine isn’t used. Instead, the surgeon steadies the heart with a mechanical device.

Off-pump CABG sometimes is called beating heart bypass grafting.

Minimally Invasive Direct Coronary Artery Bypass Grafting

For this type of heart surgery, your surgeon will make small incisions in the side of your chest between the ribs. These cuts can be as small as 2–3 inches. The surgeon will insert surgical tools through these small cuts.

A tool with a small video camera at the tip also will be inserted through an incision. This tool will allow the surgeon to see inside your body.

There are several types of minimally invasive direct coronary artery bypass (MIDCAB) grafting. These types of surgery differ from traditional bypass surgery because the chest bone isn’t opened to reach the heart. Also, a heart-lung bypass machine isn’t always used for these procedures.

MIDCAB procedure. This type of surgery mainly is used to bypass blood vessels at the front of the heart. Small incisions are made between your ribs on the left side of your chest, directly over the artery that needs to be bypassed.

The incisions usually are about 3 inches long. (The incision made in traditional CABG is at least 6 to 8 inches long.) The left internal mammary artery most often is used for the graft in this procedure. A heart-lung bypass machine isn’t used during MIDCAB grafting.

Port-access coronary artery bypass procedure. The surgeon does this procedure through small incisions (ports) made in your chest. Artery or vein grafts are used. A heart-lung bypass machine is used during this procedure.

Robot-assisted technique. –Da Vinci Robotic Surgery-This type of procedure allows for even smaller, keyhole-sized incisions. A small video camera is inserted in one incision to show the heart, while the surgeon uses remote-controlled surgical instruments to do the surgery. A heart-lung bypass machine sometimes is used during this procedure.