Coronary Artery Disease

In coronary artery disease (CAD), the arteries that supply the heart with blood (coronary arteries) are partially or completely blocked.

CAD can limit activities and prevent people from living as they would like. It can also result in death, usually due to a heart attack, a disorder involving an abnormal heart rhythm (arrhythmia), or heart failure. However, much can be done to prevent and treat CAD.

In the United States, about 1 out of 6 people 65 and over has CAD. After age 65, the likelihood that a person will develop CAD increases with each passing year. In older men and women, CAD is the most common cause of death.

The heart, like other organs, needs a constant supply of blood to bring oxygen and nutrients to it and to remove waste products. The amount of oxygen the heart needs depends on how hard it is working. During physical activity, the heart has to work harder and so needs more oxygen. The right and left coronary arteries supply heart tissue with blood. They branch off the aorta just after it leaves the heart, then divide into smaller arteries.

See the figure Blood Flow Through the Heart.

When one or more of the arteries supplying the heart are partially blocked, the heart may not get enough oxygen. This inadequate supply of oxygen, called ischemia, often causes chest pain (angina). If an artery is completely blocked, some heart tissue may die. Death of heart tissue is called a heart attack. If a lot of heart tissue dies, the heart's ability to pump blood to the rest of the body is impaired, causing heart failure. If ischemia or a heart attack affects certain areas of the heart, the heart's electrical system may malfunction, leading to an abnormal heart rhythm.

Causes

CAD is almost always caused by atherosclerosis. In atherosclerosis, cholesterol and other materials are deposited in the wall of an artery, forming plaques (atheromas). As these plaques enlarge, they partially or completely block the artery. With time, calcium accumulates in the plaques. This process usually takes many years or even decades. For this reason, CAD is more common among older people. Occasionally, a blood clot forms on a plaque, making the degree of blockage greater and sometimes blocking the artery completely.

Certain circumstances and disorders (called risk factors) can make atherosclerosis and thus CAD more likely to develop. They include the following:

• Smoking
• Physical inactivity
• Excess body weight
• Parents or siblings who developed CAD before age 50 to 55 (family history)
• Older age
• Male sex
• High blood pressure
• Abnormal levels of cholesterol and triglycerides in the blood
• Diabetes
• A high level of C-reactive protein (CRP) in the blood

If CAD is present, these risk factors can make it worse.

Smoking greatly increases the risk of developing CAD and of making it worse. The more cigarettes smoked, the greater the risk. Also, older people who continue to smoke after having a heart attack are 2 to 3 times more likely to have another heart attack or to die within 5 years than those who stop.

Men tend to develop CAD about 10 years earlier than women, because until menopause, women seem to be protected by female hormones such as estrogen. After menopause, blood pressure and cholesterol levels tend to increase, and the risk of CAD increases.

High blood pressure is the most common risk factor for CAD in older people. For most older people, blood pressure should be lower than 140/90 mm Hg (millimeters of mercury).

Diabetes is a risk factor for CAD regardless of what the levels of sugar in the blood are. If blood sugar levels are poorly controlled, the risk is even greater.

Abnormal cholesterol levels include a high level of total cholesterol, a high level of low-density lipoprotein cholesterol (LDL, the "bad" cholesterol), and a low level of high-density lipoprotein cholesterol (HDL, the "good" cholesterol). High levels of triglycerides (another fat in the blood) may also increase the risk of CAD. Diet, exercise, weight, and genes affect cholesterol and triglyceride levels.

A high level of C-reactive protein in the blood indicates persistent inflammation (as occurs in rheumatoid arthritis). Inflammation, regardless of where it occurs in the body, may damage arteries, enabling plaques to form.

A high level of homocysteine (an amino acid) in the blood may increase the risk of CAD. But the importance of a high homocysteine level is not yet known. Depression and significant stress (such as the death of a spouse) may increase risk.

Rarely, the muscle layer of a coronary artery's wall suddenly and temporarily contracts (constricts), causing a spasm. A spasm can temporarily reduce or cut off blood flow to the heart.

Symptoms

Symptoms of CAD may occur when part of the heart does not get enough oxygen, causing ischemia in heart tissue (myocardial ischemia). Or symptoms may occur when part of the heart dies—that is, when a heart attack (myocardial infarction) occurs.

The most common symptom of myocardial ischemia is discomfort in the center of the chest, behind the breastbone. This discomfort, known as angina, is often described as pressure, tightness, squeezing, or heaviness (like a weight on the chest). Angina may or may not be painful. It may be felt only in the chest, or it may move. Most commonly, it moves down the left arm. It may move to the back, throat, neck, jaw, teeth, or right arm. Angina is usually triggered by situations in which the heart is working harder and needs more oxygen than usual. Examples are physical activity or emotional stress. The discomfort usually develops gradually (without a sudden, sharp pain) and subsides gradually after a few minutes (up to about 20 minutes). Angina may occur several times a day or only once in a while. Angina is usually relieved by resting or by taking nitroglycerin (placed or sprayed under the tongue).

Occasionally, angina is accompanied by shortness of breath, nausea, dizziness, or fatigue. People may also break out in a cold sweat or feel their heart pounding (as palpitations). In older people, the only symptom may be shortness of breath that is triggered by physical activity or stress. Some people have only a sensation that resembles indigestion but is unrelated to eating. This sensation is more likely to occur during physical activity. Sometimes the only symptom is a feeling of impending doom. Any combination of these symptoms may occur. Occasionally, ischemia may cause an older person to faint.

In many people with CAD, the pattern of symptoms remains about the same for months to years. That is, symptoms are produced by the same level of physical activity, and they do not change much in severity or frequency. In other people, symptoms gradually worsen over time. In contrast, symptoms sometimes suddenly worsen: They may become more severe, occur more often, or occur during less strenuous activity. Such sudden worsening of symptoms, called unstable angina, may mean that CAD has suddenly become worse. Immediate evaluation and treatment by a doctor are essential.

Sometimes myocardial ischemia causes no symptoms. In such cases, it is called silent ischemia.

Symptoms of a heart attack are similar to those of myocardial ischemia, but they usually last longer and are more severe. As with angina, pain due to a heart attack may be felt in the chest, neck, throat, jaw, teeth, or arms. However, in older people, a heart attack may cause little or no chest pain or discomfort. Instead, a heart attack may cause shortness of breath, a smothering feeling, nausea, vomiting, sweating, dizziness, indigestion, palpitations, overwhelming fatigue, fainting, a feeling of impending doom, or any combination of these symptoms. Less commonly, older people who are having a heart attack become confused, disoriented, or restless. About one fourth of heart attacks occur without symptoms, as silent heart attacks. Silent heart attacks are more common among people with diabetes.

As people age, the heart becomes less able to handle the stress of a heart attack. Heart failure may cause accumulation of fluid in the lungs (pulmonary edema). Other common problems include low blood pressure (hypotension) and abnormal heart rhythms (arrhythmias), such as atrial fibrillation and ventricular tachycardia. Less commonly, the heart muscle may tear (rupture), or a blood clot may form in the heart. Heart attacks can also lead to cardiogenic shock, which, if untreated, results in death. In cardiogenic shock, the heart cannot pump enough blood to the brain, kidneys, and other organs. As a result, these organs cannot function. Sometimes a heart attack causes death immediately because of a very fast irregular heart rhythm (venticular fibrillation).

After a heart attack, many people feel depressed, nervous, or anxious. To some degree, these feelings are a normal reaction to having had a heart attack. However, if these feelings are too intense or if they persist for more than a few weeks, they may interfere with normal recovery, and treatment may be needed.

Diagnosis

If older people develop any of the symptoms that might be caused by CAD, they should immediately contact their doctor.

If a person has typical symptoms and risk factors for CAD, the diagnosis is usually made easily. One or more tests may be done to confirm the diagnosis and to determine how extensive CAD is.

Electrocardiography (ECG), a safe, quick, and painless test, is often done first. Small sensors (electrodes) are attached to the person's arms, legs, and chest. Electrodes detect the electrical currents produced in the heart during each heartbeat. The electrical currents are recorded as lines on a strip of graph paper (the electrocardiogram). Electrocardiography can often detect whether a heart attack is occurring or has already occurred. It may detect ischemia. However, this test does not always detect CAD, especially in people who are not having symptoms when the test is done. For this reason, a stress test is often recommended.

In a stress test, the heart has to work harder. Then, heart problems are more likely to be detected. This test is safe and can detect most cases of CAD. Stress tests often involve exercise, usually walking on a treadmill or pedaling a stationary bicycle. For people who cannot exercise, a drug such as dobutamine or adenosine can be given intravenously to stress the heart. Throughout a stress test, heart rate, blood pressure, and the electrocardiogram are recorded and closely monitored.

Echocardiography or nuclear (radionuclide) scanning may be done during a stress test. These tests are used to detect ischemia. They can also detect damage to the heart (such as that due to a heart attack) and determine how well the heart is pumping. In echocardiography, a hand-held device that sends and receives high-frequency sound (ultrasound) waves is placed on the person's chest. The ultrasound waves are used to produce a moving image of the heart. In nuclear scanning, pictures of the heart are taken after a tiny amount of a radioactive substance (radionuclide) is injected into a vein.

Sometimes computed tomography (CT) is used to detect CAD. It is done to check for calcium that can accumulate in plaques in coronary arteries. This test is simple, safe, quick, and painless. But its value in diagnosing CAD in older people is unclear. In this test, several x-rays are taken, and a computer is used to produce images of the coronary arteries.

Coronary angiography (cardiac catheterization) is the most accurate way to detect CAD and to determine the extent and location of blockages. This information helps doctors decide which treatments are best—for example, whether angioplasty or bypass surgery is needed. Cardiac catheterization can usually be done safely in people of all ages. However, it involves more risks than other tests, because it is invasive. (Invasive tests involve an incision or insertion of an instrument into the body.) The risk of serious problems is small, although the risk is somewhat higher for older people. The value of the information it provides greatly outweighs its small potential risk.

Cardiac catheterization is often recommended if symptoms and the results of other tests suggest that blockage of the coronary arteries could have serious consequences. Cardiac catheterization may also be done if other tests cannot confirm the diagnosis.

In cardiac catheterization, a long thin tube (catheter) is inserted into an artery near the hip (usually) or elbow and threaded to the heart. A dye is injected through the catheter to outline the coronary arteries and heart's chambers. Many x-rays are taken to look for blockages and to determine how well the heart is functioning.

After cardiac catheterization, the most common problem is bleeding at the site where the catheter was inserted. Usually, bleeding is mild, resulting in a bruise. Occasionally, bleeding is severe enough that a blood transfusion is needed. The risk of bleeding can be reduced by not moving the leg or arm into which the catheter had been inserted for several hours. Rarely, an artery is damaged, and surgery is needed to repair it. Other serious problems that can occur during or after cardiac catheterization include an allergic reaction to the dye, a heart attack, a stroke, an abnormal heart rhythm, and kidney failure.

If doctors suspect unstable angina or a heart attack, blood tests are done. A small amount of blood is drawn every 6 to 12 hours for 1 or 2 days. The blood is tested for proteins that are released into the bloodstream when the heart is damaged. These proteins include CK-MB, troponin I, and troponin T. If the level of any of these proteins is increased, heart tissue has been damaged or has died, probably because of a heart attack.

Prevention

Eating a healthy, well-balanced diet can help prevent CAD. Such a diet should be high in fiber and low in saturated fats, artificially hydrogenated fats (trans fatty acids), cholesterol, and foods containing simple or refined carbohydrates. It should include plenty of fruits, vegetables, and whole-grain foods.

Eliminating or controlling risk factors for CAD may help prevent the disease.

Stopping smoking is the single most important thing a person can do to prevent a heart attack. For people who smoke cigarettes, stopping smoking cuts the risk of having a heart attack in half. The benefit of stopping smoking is at least as great for older people as for younger people.

Exercising regularly can help reduce the risk of CAD. Any regular exercise is better than no exercise. A good goal is 30 minutes of exercise at least 4 days a week. For most older people, walking is best. But jogging, swimming, and stationary cycling are good alternatives. These activities are aerobic exercise. That is, they require getting a continuous supply of oxygen from the air to the muscles being exercised. Aerobic exercise improves endurance and is particularly helpful in preventing CAD. But other types of exercise—flexibility (stretching) and strengthening exercises (such as weight training)—also help by maintaining general health and fitness. Exercising regularly, even in small amounts, is particularly beneficial for people who have been doing very little or no exercise.

Before starting an exercise program, older people should check with their doctor. If chest pain, shortness of breath, dizziness, or other symptoms occur, people should stop exercising and contact their doctor.

In addition to regular exercise, developing and maintaining a more active lifestyle can also help prevent CAD. For example, daily activities, such as gardening or housecleaning, can be done more vigorously or more often. Other ways to become more active are to walk instead of drive and to take the stairs instead of the elevator whenever possible.

The risk of developing high blood pressure can be reduced. Ways to help reduce the risk include exercising regularly, maintaining a healthy weight, eating a healthy diet, and limiting the amount of salt and alcohol consumed. People who already have high blood pressure may need to take antihypertensive drugs in addition to exercising and changing their diet. Losing weight if overweight and stopping smoking are also recommended.

If cholesterol levels are abnormal, stopping smoking, exercising regularly, and eating a healthy diet can help. People should reduce the amount of saturated fat and trans fatty acids they consume. When possible, monounsaturated fats and polyunsaturated fats, particularly omega-3 fats, should be substituted for saturated fats and trans fatty acids. Eating plenty of fruits, vegetables, and whole-grain foods also helps control cholesterol levels. However, most older people with high cholesterol levels need to take drugs. Statins, such as atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin, and simvastatin, are commonly used. Statins are especially helpful for older people with diabetes, regardless of what their cholesterol levels are. Other cholesterol-lowering drugs, such as cholestyramine, ezetimibe, gemfibrozil, and niacin, are also used.

Low levels of vitamins B₆ and B₁₂ and folic acid may contribute to the risk of CAD. Many older people have low levels of these vitamins. Therefore, many experts recommend a daily multivitamin supplement containing these vitamins. Other dietary supplements do not appear to help prevent CAD.

Reaching and maintaining a healthy weight can help control several risk factors for CAD: diabetes, high blood pressure, and abnormal cholesterol and triglyceride levels. Eating a healthy diet and exercising regularly can help people reach and maintain a healthy weight.

For people with diabetes, controlling the levels of sugar in the blood can help reduce the risk of CAD. Blood sugar levels can be controlled effectively with drugs combined with diet and exercise.

Treatment

Treatment of CAD varies depending on how severe the symptoms are and how extensive the blockages are. Most older people who have stable angina can be treated with drugs without being hospitalized. However, people who have unstable angina or who are having a heart attack must be hospitalized and treated immediately.

The main goals of treatment are to improve blood flow through the coronary arteries, relieve symptoms, and prevent additional problems.

Several different types of drugs may be prescribed to treat stable angina. If drugs are not effective or if the blockage is substantial, angioplasty or coronary artery bypass graft surgery may be necessary. Both procedures are good options for older people. Both relieve symptoms and may prolong life. Which procedure is done depends largely on the location and degree of blockage.

Drugs: Most people with CAD take several types of drugs: aspirin (or a similar drug), beta-blockers, and nitrates. Some people also take calcium channel blockers, angiotensin-converting enzyme (ACE) inhibitors, and statins.

Aspirin, an antiplatelet drug, reduces the risk of heart attacks and death. Antiplatelet drugs make blood clots less likely to form by preventing platelets from sticking together. The normal function of platelets is to stick together and help form blood clots that plug tears in the lining of blood vessels. However, if platelets form a clot on fatty deposits in a coronary artery, the clot may partially or completely block the artery. A heart attack may result. Doctors recommend that most people who have CAD take a small dose of aspirin (such as one children's aspirin) daily. People with an allergy to aspirin may take another antiplatelet drug, such as ticlopidine or clopidogrel. Because aspirin and other antiplatelet drugs prevent blood from clotting normally, bleeding problems occasionally occur. Doctors may advise older people with chronic bleeding (such as that due to a bleeding ulcer) not to take antiplatelet drugs.

Beta-blockers slow the heart rate and reduce the heart's need for oxygen. They also lower blood pressure. As a result, myocardial ischemia is less likely to develop, and angina occurs less often. Beta-blockers also reduce the risk of heart attacks and sudden death and prolong life in people with CAD.

Nitrates, such as nitroglycerin, expand (dilate) blood vessels. Thus, they improve blood flow to the heart. Also, the heart does not have to work as hard to pump blood. Nitrates reduce the heart's need for oxygen. As a result, they relieve angina. Nitroglycerin can relieve angina in a few minutes. It is usually taken as a tablet or spray under the tongue. When the drug is taken this way, its effects last up to 30 minutes. People with angina should keep nitroglycerin with them at all times. Other nitrates, such as isosorbide, have effects that last longer. These drugs can be taken to prevent angina. They are available as tablets taken by mouth and as skin patches or ointments. When nitrates are used continuously, their effects wear off after a few hours. Consequently, people should not take nitrates for more than about 16 hours each day.

The most common side effect of nitrates is headache. For most people, headaches subside after a few days and do not interfere with long-term use of the drugs. Nitrates can also lower blood pressure, resulting in dizziness and sometimes fainting, especially in older people. Therefore, when taking nitroglycerin under the tongue, older people should sit or lie down.

Calcium channel blockers dilate blood vessels, improve blood flow to the heart, and lower blood pressure. These drugs also prevent spasms of the arteries. Calcium channel blockers are often used when people cannot take beta-blockers or when beta-blockers and nitrates do not relieve symptoms.

ACE inhibitors lower blood pressure and reduce the amount of work the heart has to do. These drugs reduce the risk of heart attacks, heart failure, and death. They are not used to relieve angina. The most common side effect is a dry, hacking cough. Occasionally, the cough is severe enough that the drug must be discontinued.

Statins are used primarily to control abnormal cholesterol levels. They reduce the risk of heart attacks, strokes, and death in older people with CAD. Muscle soreness that develops while taking a statin may indicate muscle damage. So if this symptom develops, people should contact their doctor immediately.

Coronary angioplasty: Coronary angioplasty (percutaneous transluminal coronary angioplasty, or PTCA) is used to physically open a blocked coronary artery. This procedure is often preferred to bypass surgery because it is less invasive. However, angioplasty may be impossible because the affected area is too large or there are too many blockages to be treated effectively with angioplasty.

During angioplasty, people are usually awake. The procedure is similar to angiography. A thin tube (catheter) with a balloon at its tip is threaded into the blocked coronary artery. Inflating the balloon opens up the artery. Often, a small tube made of wire mesh (stent) is inserted at the same time. Angioplasty with a stent is more likely to prevent the artery from becoming blocked again than is angioplasty alone. After a stent has been inserted, people are usually given clopidogrel or ticlopidine for up to several months. These drugs reduce the risk that a blood clot will block the artery again. Stents that are coated with a drug to further reduce the risk of blockages are available.

See the figure Unblocking an Artery: Angioplasty.

Sometimes angioplasty causes temporary chest pain. Other problems that can occur are the same as those for cardiac catheterization. But the risk of serious problems, including heart attacks and death, is somewhat higher.

Coronary artery bypass graft surgery (CABG): In this surgery, commonly called bypass surgery, a vein or an artery from another part of the body is used to bypass the blocked coronary artery. Bypass surgery is usually recommended when there are several blockages or when the blockages occur throughout the length of a coronary artery. In such cases, angioplasty is unlikely to be effective. More than half of people who have bypass surgery are 65 or over.

For bypass surgery, a segment of an artery or a vein from another part of the body is attached (grafted) to the coronary artery. Thus, the blocked area is skipped (bypassed). Arteries are preferred to veins because they are less likely to become blocked.

See the figure Bypassing a Coronary Artery.

Usually, more than one blockage is bypassed. A triple bypass means that three blocked coronary arteries are bypassed. A quadruple bypass means that four coronary arteries are bypassed. A higher number of blocked, bypassed arteries does not necessarily mean that the surgery was riskier or that the long-term outlook is worse.

During surgery, the heart is usually stopped from beating because operating on a heart that is not moving is easier. A heart-lung machine is used to pump blood through the bloodstream.

Bypass surgery usually takes 3 to 5 hours. After surgery, people typically spend 1 to 3 days in intensive care and a total of 5 to 10 days in the hospital. Most older people need several weeks to recuperate before they can resume their normal activities.

Less invasive (and possibly less risky) techniques for bypass surgery are available. These techniques include "off-pump" surgery (in which the heart is left beating) and surgery with a smaller chest incision. The safety and effectiveness of these techniques in older people are being studied.

Bypass surgery is routine and relatively safe. However, risks are higher for older people than for younger ones, partly because older people are more likely to have other disorders that increase risk (such as diabetes, lung disorders, or kidney disorders). Problems that can occur after bypass surgery include strokes, abnormal heart rhythms, temporary confusion, difficulty breathing, pulmonary embolism, bleeding, infections, kidney failure, and death.

Emergency treatment: Anyone with angina that is worsening (unstable angina) or with symptoms that may indicate a heart attack should take one aspirin, call an emergency telephone number (such as 911), and get to a hospital immediately. The aspirin should be chewed so that it is absorbed more quickly.

The sooner treatment begins, the better the person's outlook. In cases of a heart attack, prompt transportation by an ambulance to an emergency department may save the person's life. Spending time trying to contact the person's doctor or waiting for family members to arrive delays treatment and is dangerous. People who have unstable angina are usually hospitalized. Those who are having a heart attack are always hospitalized.

In the emergency department, people who may have unstable angina or who have symptoms of a heart attack are given aspirin (by mouth) and oxygen (through nasal prongs or a face mask). Most people are given nitroglycerin (under the tongue, as ointment, or intravenously) and morphine (intravenously). A beta-blocker may also be given (intravenously or by mouth). Heparin, a drug that makes blood less likely to clot (anticoagulant), is often given (intravenously or by injection under the skin).

While treatment is being started, electrocardiography and blood tests are done. If these tests confirm unstable angina or a heart attack, additional treatments may be given. Glycoprotein IIb/IIIa inhibitors may be given intravenously in addition to aspirin and heparin. These drugs are powerful antiplatelet drugs that help prevent new blood clots from forming in a coronary artery.

People who have had a major heart attack may be given a drug that dissolves blood clots (thrombolytic drug). Dissolving the clot in the blocked coronary artery restores blood flow to the heart. Thus, damage to the heart is reduced, and the outlook is improved. These drugs are useful only when given within the first 6 to 12 hours of a heart attack.

Rarely, thrombolytic drugs cause serious bleeding, including bleeding into the brain. This problem occurs in fewer than 1 out of 100 people, but the risk is higher for older people. The risk is also higher for people who have very high blood pressure or who have had a stroke.

An alternative to thrombolytic drugs is cardiac catheterization, done immediately and followed by angioplasty (often with a stent). This technique opens a blocked artery more effectively than thrombolytic drugs and is less likely to result in a stroke. However, fewer than 1 out of 5 hospitals in the United States can do this procedure in an emergency situation. Rarely, cardiac catheterization done at the time of a heart attack detects extensive blockage that requires emergency bypass surgery.

Additional treatments may be needed for problems that develop after a heart attack, such as abnormal heart rhythms, heart failure, or pulmonary edema. Rarely, surgery is needed to repair a tear (rupture) in the heart caused by a heart attack.

After a heart attack, people are often given aspirin, clopidogrel or ticlopidine (especially if a stent has been inserted), a beta-blocker, an ACE inhibitor, and a statin. Some people may also be given nitrates, a calcium channel blocker, or warfarin (an anticoagulant). People who cannot tolerate an ACE inhibitor because of cough or other side effects may be given an angiotensin II receptor blocker.

Rehabilitation: After a heart attack or bypass surgery, rehabilitation is usually helpful. Rehabilitation begins in the hospital with such activities as getting out of bed, sitting in a chair, and going to the bathroom. People are encouraged to walk as soon as they are physically able. Resuming activities soon after a heart attack or bypass surgery helps prevent problems (such as blood clots in the legs) and speeds recovery.

After discharge from the hospital, activities should be gradually increased over a period of 2 to 4 weeks. If possible, people should walk a little each day. People should increase their walking time gradually until they can walk 20 to 30 minutes comfortably. Most people can resume sexual activity, drive, and go back to work within 2 to 4 weeks after discharge. Lifting heavy objects or weights should be avoided for at least 4 weeks. The return to usual activities may be slower if the heart attack was extensive or if problems develop after bypass surgery.

Many older people, especially those who were not in good physical condition before the heart attack, benefit from continuing rehabilitation in a cardiac rehabilitation program. These programs include exercise sessions supervised by a trained exercise specialist. People are also taught how to change to a lifestyle that can help reduce the risk of another heart attack. Typically, people attend three sessions a week for 8 to 12 weeks.

Long-term treatment: Most people who have had a heart attack must continue to take drugs for the rest of their life. These drugs may include aspirin or another antiplatelet drug, a beta-blocker, an ACE inhibitor, and a statin. Some people are given an anticoagulant (usually warfarin), a nitrate, a calcium channel blocker, or several of these drugs. People who cannot tolerate an ACE inhibitor because of cough or other side effects may be given an angiotensin II receptor blocker.

Eliminating or controlling risk factors is a lifelong task, even when angioplasty or bypass surgery is done. If risk factors are not eliminated or controlled, CAD tends to worsen and cause additional problems. Blood pressure, cholesterol levels, and weight should be kept within recommended ranges if possible. Smokers should stop smoking. Eating a low-fat, healthy diet is recommended. Most people are advised to exercise regularly. Learning to manage stress, when possible, may help.

If depression lasts more than 2 weeks after discharge from the hospital, treatment is needed. If family members notice that depression is persisting, they should encourage the person to contact the doctor. Without treatment, people with depression recover more slowly and have more serious problems later. People with depression are more likely to die during the first year after a heart attack. Treatment of depression, which includes counseling and antidepressant drugs, is usually effective. Regular exercise, which improves mood and strengthens the heart, may help.

Outlook

CAD tends to worsen over time. Blockages tend to worsen so that less and less blood flows through the blocked arteries, and new blockages tend to develop. Angina tends to worsen. However, eliminating or controlling risk factors can delay and even prevent development and worsening of blockages. Treatment can relieve angina for years or even decades.

For people who have had a heart attack, the outlook depends on how much of the heart has been damaged. If a heart attack is massive or causes certain abnormal heart rhythms, death may occur within seconds, minutes, or days. However, most people who survive for a few days after a heart attack recover. They may live, sometimes with few or no symptoms, for years or decades afterward. The outlook is worse for people who continue to have angina or abnormal heart rhythms or who develop heart failure. Following a healthy lifestyle and taking the drugs that the doctor prescribes can help prevent a heart attack and improve the outlook.

Sometimes because of a person's condition, treatments such as bypass surgery and angioplasty are too risky or will not prolong life. For example, these treatments may not benefit older people who have very advanced CAD, extensive damage to the heart, or other serious disorders (such as severe lung disorders or advanced cancer). These people are unlikely to survive for more than a few months. Care then focuses on relieving symptoms, such as pain and shortness of breath, and on making the person's remaining days as comfortable and fulfilling as possible.

In people with CAD, death often occurs without warning. Death can occur quickly, before any symptoms develop or before they become bothersome. Such a death may result from a heart attack or an abnormal heart rhythm. Or death can occur after a period of chronic illness with ups and downs. Such a death may result from heart failure. Consequently, people with CAD, even those without significant symptoms, should prepare advance directives, stating what kind of care they want at the end of life.

See the sidebar Recognizing a Heart Attack.

See the table Drugs Used for Coronary Artery Disease.