Coronary artery disease
Coronary Artery Disease
Coronary artery disease (CAD), also called heart disease, is a condition in which fatty deposits called plaque build-up in the heart’s arteries. These deposits cause arteries to become narrow and blocked, which restricts blood and oxygen flow to the heart muscle. CAD is the leading cause of death, for both men and women, in the United States.
The most important factors that increase the risk for CAD are:
Angina is the primary symptom of coronary artery disease. Angina feels like gripping pain or pressure in the chest area.
Some patients with CAD have few or no symptoms. Sometimes a heart attack may be the first sign that a person has CAD.
The American College of Cardiology, American Heart Association, and other professional organizations have released several new guidelines in the past year. Updated recommendations include:
Coronary artery disease (CAD), also called heart disease or ischemic heart disease, results from a complex process known as atherosclerosis (commonly called "hardening of the arteries"). In atherosclerosis, fatty deposits (plaques) of cholesterol and other cellular waste products build up in the inner linings of the heart’s arteries. This causes blockage of arteries and prevents oxygen-rich blood from reaching the heart (ischemia). There are many steps in the process leading to atherosclerosis, some not fully understood.
Cholesterol and Lipoproteins. The atherosclerosis process begins with cholesterol and sphere-shaped bodies called lipoproteins that transport cholesterol.
Oxidation. The damaging process called oxidation is an important trigger of atherosclerosis:
Inflammatory Response. For the arteries to harden there must be a persistent reaction in the body that causes ongoing harm. Researchers now believe that this reaction is an immune process known as the inflammatory response.
There is growing evidence that the inflammatory response may be present not only in local plaques in single arteries but also throughout the arteries leading to the heart.
Blockage in the Arteries. Eventually the calcified (hardened) arteries become narrower (a condition known as stenosis).
The End Result: Heart Attack. A heart attack can occur as a result of one or two effects of atherosclerosis:
The external structures of the heart include the ventricles, atria, arteries, and veins. Arteries carry blood away from the heart while veins carry blood into the heart. The vessels colored blue indicate the transport of blood with relatively low content of oxygen and high content of carbon dioxide. The vessels colored red indicate the transport of blood with relatively high content of oxygen and low content of carbon dioxide.
Heart disease is the leading cause of death in the United States. Over the past decades, heart disease rates declined in both men and women as they quit smoking and improved dietary habits. This improvement, however, has leveled off in recent years, most likely because of the dramatic increase in obesity in the U.S. and other industrialized nations.
The risks for coronary artery disease increase with age. About 85% of people who die from heart disease are over the age of 65.
Men have a greater risk for coronary artery disease and are more likely to have heart attacks earlier in life than women. Women’s risk for heart disease increases after menopause, and they are more likely to have angina than men.
Certain genetic factors increase the likelihood of developing important risk factors such as diabetes and high blood pressure. Heart disease tends to run in families. People whose parents or siblings developed heart disease at a younger age are more likely to develop it themselves.
African-Americans have the highest risk of heart disease, in part due to their high rates of severe high blood pressure, as well as diabetes and obesity.
Smoking. Smoking is the most important risk factor for heart disease. Smoking can cause elevated blood pressure, worsen lipids, and make platelets very sticky, raising the risk of clots. Although heavy cigarette smokers are at greatest risk, people who smoke as few as three cigarettes a day are at increased risk for blood vessel abnormalities that endanger the heart. Regular exposure to secondhand smoke also increases the risk of heart disease in nonsmokers.
Alcohol. Moderate alcohol consumption (one or two drinks a day; 5 ounces wine, 12 ounces beer, or 1.5 ounces hard liquor is one drink) can help boost HDL “good” cholesterol levels. Alcohol may also prevent blood clots and inflammation. By contrast, heavy drinking harms the heart. In fact, heart disease is the leading cause of death in alcoholics.
Diet. Diet plays an important role in the health of the heart, especially in controlling dietary sources of cholesterol and restricting salt intake that contributes to high blood pressure.
Physical Inactivity. Exercise has a number of effects that benefit the heart and circulation, including improving cholesterol and lipids, lowering blood pressure and blood sugar levels, and improving weight control. People who are sedentary are almost twice as likely to suffer heart attacks as are people who exercise regularly.
Obesity and Metabolic Syndrome. Excess body fat, especially around the waist, can increase the risk for heart disease. Obesity also increases the risk for other conditions (such as high blood pressure and diabetes) that are associated with heart disease. Obesity is particularly hazardous when it is part of the metabolic syndrome, a pre-diabetic condition that is significantly associated with heart disease. This syndrome is diagnosed when three of the following are present:
There are numerous way to control your weight and diet.
Unhealthy Cholesterol and Lipid Levels. Low-density lipoprotein (LDL) cholesterol is the "bad" cholesterol responsible for many heart problems. Triglycerides are another type of lipid (fat molecule) that can be bad for the heart. High-density lipoprotein (HDL) cholesterol is the "good" cholesterol that helps protect against heart disease. Doctors test for a "total cholesterol" profile that includes measurements for LDL, HDL, and triglycerides. The ratio of these lipids can affect heart disease risk.
High Blood Pressure. High blood pressure (hypertension) is associated with coronary artery disease. For an adult, a normal blood pressure reading is below 120/80 mm Hg. High blood pressure is generally considered to be a blood pressure reading greater than or equal to 140 mm Hg (systolic) or greater than or equal to 90 mm Hg (diastolic). Blood pressure readings in the prehypertension category (120 - 139 systolic or 80 - 89 diastolic) indicate an increased risk for developing hypertension.
Diabetes. Diabetes, especially for people whose blood sugar levels are not well controlled, significantly increases the risk of developing heart disease. In fact, heart disease and stroke are the leading causes of death in people with diabetes. People with diabetes, both type 1and type 2, are also at risk for high blood pressure and unhealthy cholesterol levels, blood clotting problems, and impaired nerve function, all of which can damage the heart.
Peripheral Artery Disease. Peripheral artery disease (PAD) occurs when atherosclerosis affects the extremities, particularly the feet and legs. The major risk factors for heart disease and stroke are also the most important risk factors for PAD. (The combination of such conditions with PAD also produces more severe forms of heart or circulatory disease.) Even though signs of heart disease are often not evident in the majority of patients with PAD, most of these patients also have coronary artery disease.
Depression. Although people with heart disease may become depressed, this does not explain entirely the link between the two problems. Data suggest that depression itself may be a risk factor for heart disease as well as its increased severity. A number of studies indicate that depression has biologic effects on the heart, including blood clotting and heart rate. Guidelines recommend that patients who have undergone coronary artery bypass surgery or angioplasty (PCI) be screened for depression. Stress may also contribute to risk.
Homocysteine and Vitamin B Deficiencies. Deficiencies in the B vitamins folate (known also as folic acid), B6, and B12 have been associated with a higher risk for heart disease in some studies. Such deficiencies produce higher blood levels of homocysteine, an amino acid that has been associated with a higher risk for heart disease, stroke, and heart failure.
However, while B vitamin supplements do help lower homocysteine levels, they appear to have no effect on heart disease outcomes, including preventing heart attack or stroke. Research indicates that homocysteine may be a marker for heart disease rather than a cause of it.
C-Reactive Protein. C-reactive protein (CRP) is a product of the inflammatory process. It is not known if the protein plays any causal role or whether it is simply a marker for other factors in the disease process.
C. pneumoniae and Other Infectious Organisms. Some microorganisms and viruses have been under suspicion for triggering the inflammation and damage in the arteries that contribute to heart disease. The strongest evidence to date supports a possible role from Chlamydia (C.) pneumoniae (an atypical bacterial organism that causes mild pneumonia in young adults). C. pneumoniae has been detected in plaques in the arteries of patients with heart disease. However, treatment with appropriate antibiotics has not been found to reduce the risk of future heart problems for patients infected with this organism.
Other studies suggest that cytomegalovirus (CMV), a common virus, may have similar effects. Many people, however, have been infected with these organisms, and no clear association has been found with any of these infections.
Sleep Apnea. Obstructive sleep apnea is a condition in which tissues in the upper throat sag at intervals during sleep, thereby blocking the passage of air. Patients with severe, untreated apnea are at increased risk for CAD, high blood pressure, stroke, and heart attack. However, there is no evidence to date that obstructive sleep apnea is an independent cause of cardiac events or stroke.
Periodontal Disease. Periodontal disease and heart disease are both inflammatory conditions. There appears to be an association between periodontal disease and CAD, but it is not yet clear if having one condition increases the risk of developing the other. Patients who have periodontal disease and at least one risk factor for heart disease should have a medical evaluation for heart problems. Patients who have CAD should have regular exams to check for signs of periodontal disease.
Common symptoms of coronary artery disease (CAD) include angina, shortness of breath (particularly during physical exertion), and rapid heartbeat. Sometimes patients with CAD have few or no symptoms until they have heart attack or heart failure.
Angina is a symptom, not a disease. It is the primary symptom of coronary artery disease and, in severe cases, of a heart attack. It is typically felt as chest pain and occurs as a consequence of a condition called myocardial ischemia. Ischemia results when the heart muscle does not get as much blood (and, as a result, as much oxygen) as it needs for a given level of work. Angina is usually referred to as one of two states:
Angina may be experienced in different ways and can be mild, moderate, or severe. The intensity of the pain does not always relate to the severity of the medical problem. Some people may feel a crushing pain from mild ischemia, while others might feel only mild discomfort from severe ischemia.
Stable Angina. Stable angina is predictable chest pain. Although less serious than unstable angina, it can be extremely painful or uncomfortable. It is usually relieved by rest and responds well to medical treatment (typically nitroglycerin). Any event that increases oxygen demand can cause an angina attack. Some typical triggers include:
Angina attacks can happen at any time during the day, but most occur between 6 a.m. and noon.
Specific symptoms that are more likely to indicate angina include:
Other symptoms that may indicate angina or accompany the pain or pressure in the chest include:
Unstable angina is a much more serious situation and is often an intermediate stage between stable angina and a heart attack, in which an artery leading to the heart (a coronary artery) becomes completely blocked. A patient is usually diagnosed with unstable angina under one or more of the following conditions:
Unstable angina is usually discussed as part of a condition called acute coronary syndrome (ACS). ACS also includes people with a condition called NSTEMI (non ST-segment elevation myocardial infarction) -- also referred to as non-Q wave heart attack. With NSTEMI, blood tests indicate a developing heart attack. These conditions are less severe than full-blown heart attacks but may develop into major attacks without aggressive treatment.
Prinzmetal's Angina. A third type of angina, called variant or Prinzmetal's angina, is caused by a spasm of a coronary artery. It almost always occurs when the patient is at rest. Irregular heartbeats are common, but the pain is generally relieved promptly with standard treatment.
Silent Ischemia. Some people with severe coronary artery disease do not have angina pain. This condition is known as silent ischemia, which may occur when the brain abnormally processes heart pain. This is a dangerous condition because patients have no warning signs of heart disease. Some studies suggest that people with silent ischemia have higher complication and mortality rates than those with angina pain. (Angina pain may actually protect the heart by conditioning it before a heart attack.)
Chest pain is a very common symptom in the emergency room, but heart problems account for less than half of all chest pain episodes. There are many other causes of chest pain or discomfort including injured muscles, arthritis, heartburn, and asthma. Still, if you are experiencing chest pain, it is best to seek immediate medical attention.
Many tests can diagnose possible heart disease. The choice of which (and how many) tests to perform depends on the patient's risk factors, history of heart problems, and current symptoms. Usually the tests begin with the simplest and may progress to more complicated ones.
Doctors routinely check for high blood pressure and unhealthy cholesterol levels in all older adults. Specific tests are also important in people who may have risk factors or symptoms of diabetes.
An electrocardiogram (ECG) measures and records the electrical activity of the heart. Up to half of people who suffer from angina or silent ischemia, however, have normal ECG readings. The waves measured by the ECG correspond to when different parts of the heart contract and relax. Specific waves seen on an ECG are named with letters:
The electrocardiogram (ECG, EKG) is used extensively in the diagnosis of heart disease, from congenital heart disease in infants to myocardial infarction and myocarditis in adults. Several different types of electrocardiogram exist.
The most important wave patterns in diagnosing and determining treatment for heart disease and heart attack are called ST elevations and Q waves.
Exercise stress test for evaluation of coronary artery disease may be performed in the following situations:
Basic Procedure. A stress test (exercise tolerance test) monitors the patient's heart rhythms, blood pressure, and clinical status. It can tell how well the heart handles work and if parts of the heart have decreased blood supply. A typical stress test involves:
An ECG is used to monitor heart rhythms during a stress test. (An echocardiogram or more advanced imaging technique may also be used to visualize the actions of the heart and blood flow.)
Interpreting Results. To accurately assess heart problems, a variety of factors are measured or monitored using the ECG and other tools during exercise. They include:
Using these and other measures, doctors can determine risk fairly accurately, particularly for men with chronic stable angina. The test has limitations, however, and some are significant. In patients with suspected unstable angina, normal or low risk results may not be as accurate in predicting future risk of cardiac events.
About 10% of patients, particularly younger people, will have false positive test results. In such cases, test results indicate abnormalities when there are no heart problems. In addition, for many reasons, the test is less accurate in women and an echocardiogram may be a more accurate procedure for them.
An echocardiogram is a noninvasive test that uses ultrasound images of the heart. This test is more expensive than an ECG, but it can be very valuable, particularly in identifying whether there is damage to the heart muscle and the extent of heart muscle damage.
A stress echocardiogram may be performed to further evaluate abnormal findings from an exercise treadmill test or a routine echocardiogram. Examples include identifying exactly which part of the heart may be involved and quantifying how much muscle has been infected. It may be the first test done when the exercise treadmill test cannot be performed due to certain abnormal rhythms.
Radionuclide procedures use imaging techniques and computer analyses to plot and detect the passage of radioactive tracers through the region of the heart. Such tracing elements are typically given intravenously. Radionuclide imaging is useful for diagnosing and determining:
Myocardial Perfusion (Blood Flow) Imaging Test (also called the Thallium Stress Test). This radionuclide test is typically used with an exercise stress test to determine blood flow to the heart muscles. It is a reliable measure of severe heart events. It may be useful in determining the need for angiography if CT scans have detected calcification in the arteries. About a minute before the patient is ready to stop exercising, the doctor administers a radioactive tracer into the intravenous line. (Tracers include thallium, technetium, or sestamibi.) Immediately afterwards, the patient lies down for a heart scan. If the scan detects damage, more images are taken 3 or 4 hours later. Damage due to a prior heart attack will persist when the heart scan is repeated. Injury caused by angina, however, will have resolved by that time.
Radionuclide Angiography. This is a technique for visualizing the chambers and major blood vessels of the heart. It uses an injected radioactive tracer and can be performed during exercise, at rest, or with use of stress-inducing drugs. It can help determine the severity of coronary artery disease and is an alternative to echocardiograms in certain situations.
Angiography is an invasive test. It is used for patients who show strong evidence for severe obstruction on stress and other tests, and for patients with acute coronary syndrome. It is required when there is a need to know the exact anatomy and disease present within the coronary arteries. A limitation of angiography is that it is not always the most occluded (narrowed) artery that causes the next heart attack. In an angiography procedure:
Magnetic Resonance Angiography (MRA). MRA is a newer noninvasive imaging technique that can provide three-dimensional images of the major arteries to the heart.
Computed tomography (CT) scans may be used to evaluate coronary artery disease.
Calcium Scoring CT Scans of the Heart. These scans are used to detect calcium deposits on the arterial walls. The presence of calcium correlates well with the presence of atherosclerosis of the heart. If the calcium score is very low, a patient is unlikely to have coronary artery disease. A higher calcium score may indicate an increased risk of current and future coronary artery disease. However, the presence of calcium does not necessarily signify narrowing of the arteries that would need further immediate evaluation or treatment.
CT Angiography. CT scans may also be used to visualize the coronary arteries. When compared to invasive angiography, CT angiography is not as accurate in identifying who truly has coronary artery disease and who does not. Other types of newer CT techniques include electron beam computed tomography and multidetector computed tomography.
Heart disease prevention is important before and after someone is diagnosed with the condition:
Key prevention measures include:
Your doctor should ask about your smoking habits at every visit. Smoking is a chronic condition and often requires repeat therapy using more than one technique.
All patients should start following a heart-healthy diet and exercise regularly, after talking to their doctors.
Healthy diet, regular exercise, and quitting smoking (if you smoke) may prevent heart disease. Follow your health care provider's recommendations for treatment and prevention of heart disease.
Patients with CAD should aim for LDL cholesterol levels of less than 100 mg/dL. (Doctors may recommend levels below 70 mg/dL for certain patients.) If patients cannot reach the LDL target through lifestyle measures, current guidelines recommend a statin drug. Statin drugs are the primary medications used for lowering LDL (“bad”) cholesterol levels.
Keep Blood Pressure Low. People in normal health should have a blood pressure reading of 120/80 mm Hg or less. Blood pressure readings of 120/80 are considered normal, readings of 140/90 or higher indicate high blood pressure (hypertension), and readings in between the two are called pre-hypertension. Patients with CAD should aim for blood pressure readings of less than 130/80 mm Hg. If they cannot achieve this target, current guidelines recommend that they receive at least two blood pressure medications.
All patients with diabetes should have their blood sugar (glucose) levels well managed. For most patients, a goal would be to bring HbA1c levels down to around 7%. Blood pressure goals for people with diabetes, both type 1 and type 2, are currently being reexamined. At this time, the recommended goal is to maintain blood pressure readings of 130/80 mm Hg.
Current American Heart Association (AHA) for guidelines for a heart-healthy diet recommend:
People should aim for a BMI index of 18.5 - 24.9. Weight reduction is recommended for obese patients who have high blood pressure, high cholesterol levels, metabolic syndrome, or diabetes.
Some obese patients with coronary artery disease may consider having bariatric surgery (stomach bypass) to lose excess weight. The weight lost after surgery can help improve blood pressure, cholesterol, blood sugar and other factors associated with CAD.
Everyone in normal health should do at least moderate physical activity for a minimum of 30 - 60 minutes on most, if not all, days of the week
Even low amounts of moderate or high intensity exercise (walking or jogging 12 miles a week) can help produce beneficial changes in cholesterol and lipid levels. However, more prolonged exercise is required to significantly change cholesterol levels, notably by increasing HDL ("good cholesterol"). Resistance (weight) training has also been associated with heart protection.
Your doctor needs to know if your activity causes any angina symptoms. Sudden strenuous exercise (especially snow shoveling) puts many people at risk for angina and heart attack. Patients with angina should never exercise shortly after eating. People with risk factors for heart disease should seek medical clearance and a detailed exercise prescription. And all people, including healthy individuals, should listen carefully to their bodies for signs of distress as they exercise.
Sexual Activity. Most patients with stable CAD can safely engage in sexual activity. Patients with severe heart disease should abstain from sex until their condition has stabilized. Exercise and cardiac rehabilitation can help lower the risks associated with sexual exertion.
PDE5 inhibitor drugs [sildenafil (Viagra), vardenafil (Levitra), tadalafil (Cialis), avanafil (Stendra)] are safe and helpful for most patients with stable CAD who have issues with erectile dysfunction. However, patients who take nitrate drugs in any form must never take PDE5 inhibitors.
Patients with CAD are considered at high risk for complications from influenza. People with CAD should get an annual flu shot.
Lifestyle changes (such as weight control, exercise, and quitting smoking) are the first approach for all degrees of coronary artery disease. Depending on severity and individual conditions, patients may also need one or more medications, surgery, or both.
Medications. Many types of medications are used to treat angina and CAD. They include:
Interventional Procedures and Surgery. Intervention is usually recommended for people who have:
The two main surgical procedures for patients with coronary artery disease are:
The decision to choose angioplasty or coronary artery bypass depends on a patient’s individual profile, including the number and types of coronary arteries involved, the health stability, previous procedures, patient preference, and more.
Patients considering surgery should discuss all options and risks with their doctors. Guidelines recommend that patients with CAD discuss their treatment options with a medical team that includes both a cardiac surgeon (who performs CABG) and an interventional cardiologist (who performs PCI). No surgical procedure cures coronary artery disease, and patients must continue to rigorously maintain a healthy lifestyle and any necessary medications. For some patients, lifestyle changes and medications may be able to control the disease without surgery or angioplasty.
Anti-clotting drugs that inhibit or break up blood clots are used at every stage of heart disease. They are generally classified as either anti-platelets or anticoagulants. Both anti-platelets and anticoagulants prevent blood clots from forming, but they work in different ways. Anti-platelets prevent blood platelets from sticking together. Anticoagulants are “blood thinners” that stop blood from clotting. Both of these therapies carry the risk of bleeding, which can lead to dangerous situations, including stroke.
For most patients with CAD, anti-platelet drugs are preferred over anticoagulants. Anticoagulants may be prescribed for patients with atrial fibrillation or prosthetic heart valves.
Current guidelines recommend that patients with CAD receive anti-platelet therapy with either aspirin or clopidgorel. Two newer anti-platelet drugs, Prasugrel (Effient) and ticagrelor (Brilinta), may be recommended for patients with acute coronary syndrome (unstable angina or early signs of heart attack) who have received a stent during PCI.
A thrombus is a blood clot that forms in a vessel and remains there. An embolism is a clot that travels from the site where it formed to another location in the body. Thrombi or emboli can lodge in a blood vessel and block the flow of blood in that location depriving tissues of normal blood flow and oxygen. This can result in damage, destruction (infarction), or even death of the tissues (necrosis) in that area.
Aspirin. Aspirin is known as a nonsteroidal anti-inflammatory drug (NSAID). It stops blood platelets, which are major clotting factors, from sticking together to form a blood clot. Aspirin therapy is extremely beneficial for patients with coronary artery disease or history of stroke.
If you have been diagnosed with CAD, your doctor may recommend that you take a daily dose (from 75 – 162 mg) of aspirin. A daily dose of 81 mg is recommended for patients who have undergone PCI (angioplasty). Aspirin can reduce the risk of heart attack and ischemic stroke. However, prolonged use of aspirin can increase the risks for stomach bleeding. A doctor needs to consider a patient’s overall medical condition and risk factors for heart attack before recommending aspirin therapy.
A daily low-dose aspirin (75 - 81 mg) is usually the first choice for preventing heart disease or stroke in high-risk individuals. In general, daily low-dose aspirin is recommended for prevention of heart disease for the following people who have never had a heart attack or stroke:
Clopidogrel. Thienopyridines are anti-platelet drugs. Clopidogrel (Plavix, generic) is the standard thienopyridine for patients with CAD. Prasugrel (Effient) is a new thienopyridine that may be prescribed for patients with acute coronary syndrome.
For heart disease primary and secondary prevention, daily aspirin is generally the first choice. Clopidogrel is prescribed instead of aspirin for patients who are aspirin allergic or who cannot tolerate aspirin. For most patients, clopidogrel is not taken in combination with aspirin because the two drugs combined can increase the risk of bleeding.
Clopidogrel is also recommended for patients who are undergoing angioplasty. Patients who receive drug-coated stents require prolonged clopidogrel therapy. Patients having coronary bypass surgery should not take clopidogrel for at least 5 days prior to surgery because of a significant bleeding risk.
Thienopyridine anti-platelet drugs like clopidogrel can increase the risk for upper gastrointestinal bleeding, especially for patients who have pre-existing ulcers or other risk factors. For this reason, some doctors recommend that patients who are at high risk of gastrointestinal bleeding take a proton pump inhibitor (PPI) drug along with clopidogrel. PPI drugs help suppress gastric acid production, which in turn helps heal ulcers. However, PPI drugs can interfere with clopidogrel’s anti-platelet effects. Discuss with your doctor the risks and benefits of taking a PPI drug along with clopidogrel and whether this is right for you.
Beta blockers are useful for preventing angina attacks and reducing high blood pressure. They reduce the heart's oxygen demand by slowing the heart rate and lowering blood pressure. They can help reduce risk of death from heart disease and from heart surgeries, including PCI and coronary bypass.
Beta blockers are used or recommended in a number of situations:
Beta blockers include propranolol (Inderal), carvedilol (Coreg), bisoprolol (Zebeta), acebutolol (Sectral), atenolol (Tenormin), labetalol (Normodyne, Trandate), metoprolol (Lopressor, Toprol-XL), and esmolol (Brevibloc). All of these drugs are available in generic form. A nasal spray form of propranolol may be helpful in reducing exercise-induced angina attacks.
Side Effects. Beta blocker side effects include fatigue, lethargy, vivid dreams and nightmares, depression, memory loss, and dizziness. They can lower HDL (“good”) cholesterol. Beta blockers are categorized as non-selective or selective. Non-selective beta blockers, such as carvedilol and propranolol, can narrow bronchial airways. These beta blockers should not be used by patients with asthma, emphysema, or chronic bronchitis.
PATIENTS SHOULD NEVER ABRUPTLY STOP TAKING THESE DRUGS. The sudden withdrawal of beta blockers can rapidly increase heart rate and blood pressure. The doctor may advise a patient to slowly decrease the dose before stopping completely.
Angiotensin converting enzyme (ACE) inhibitors are important heart-protective drugs, particularly for people with diabetes and high blood pressure. They reduce the production of angiotensin, a chemical that causes arteries to narrow, and so are commonly used to lower blood pressure. They may also reduce risk for heart attack, stroke, complications of diabetes, and death in patients at high risk for heart disease.
ACE inhibitors are indicated for most patients who have had heart attacks. They are particularly helpful for patients with coronary artery disease who also have diabetes or who have heart failure or left ventricular dysfunction (when the heart's main chamber does not pump as well as it should).
ACE inhibitors include captopril (Capoten, generic), ramipril (Altace, generic), enalapril (Vasotec, generic), quinapril (Accupril, generic), benazepril (Lotensin, generic), perindopril (Aceon, generic), and lisinopril (Prinivil, Zestril, generic).
Side Effects. Side effects of ACE inhibitors may include an irritating cough. More serious side effects are uncommon but may include excessive drops in blood pressure, allergic reactions, and high blood potassium levels. If you cannot tolerate the side effects of ACE inhibitors, your doctor may prescribe an angiotensin receptor blocker (ARB) as an alternative high blood pressure drug.
Nitrates have been used in the treatment of angina for over 100 years. These drugs release nitric oxide, thereby relaxing the smooth muscles in blood vessels. Nitrates are used primarily for control of angina symptoms. Many nitrate preparations are available. The most commonly used are nitroglycerin, isosorbide dinitrate, and isosorbide mononitrate. Nitrates can be absorbed from the gastrointestinal tract (oral tablet), skin (ointment or patch), or from under the tongue (sublingual tablet or spray).
Rapid Acting Nitrates. Rapid-acting nitrates are used to treat acute attacks. Nitroglycerin is the most widely used drug for this purpose. It can be administered under the tongue (sublingually or as a spray) or pocketed between the upper lip and gum (buccally) and can relieve angina within minutes. The procedure for taking nitroglycerin during an attack is as follows:
Nitroglycerin is very unstable so its potency can be easily lost. Patients should take the following precautions:
Intermediate to Long-Term Nitrates. Sublingual tablets of isosorbide dinitrate have a slower onset of action than nitroglycerin and are useful for preventing exercise angina. Ointments, skin patches, and oral tablets are used for longer-term prevention of angina attacks:
Long-acting forms may lose their effectiveness over time, so doctors generally schedule nitrate-free breaks to prevent tolerance.
Side Effects. Nitrates can have many side effects, some of which can be serious.
Common side effects of nitrates include headaches, dizziness, nausea and vomiting, blurred vision, fast heartbeat, sweating, and flushing on the face and neck. Low blood pressure and dizziness can be relieved by lying down with the legs elevated. These effects are significantly worsened by alcohol, beta blockers, calcium channel blockers, and certain antidepressants. Patients who take nitrates in any form cannot take medications for erectile dysfunction, such as sildenafil (Viagra), vardenafil (Levitra), tadalafil (Cialis), and avanafil (Stendra). The doctor may prescribe medicines to lessen these side effects. Patients should contact their doctor if these side effects are persistent or severe.
Serious side effects requiring immediate medical help include fever, joint or chest pain, sore throat, skin rash (especially on the face), unusual bleeding or bruising, weight gain, and swelling of the ankles.
Withdrawal. Withdrawal from nitrates should be gradual. Abrupt termination may cause angina attacks.
Calcium channel blockers reduce heart rate and slightly dilate the blood vessels of the heart, thereby decreasing oxygen demand and increasing oxygen supply. They also reduce blood pressure. CCBs vary chemically, however, and although some are helpful, others may even be dangerous for certain patients with CAD.
There is no strong evidence that any calcium channel blockers improve survival rates. Overdose can cause dangerously low blood pressure and slow heart beats. Patients with heart failure have a higher risk for death with these drugs and should not take them. No one taking any calcium channel blocker should withdraw abruptly because such action could dangerously increase the risk of high blood pressure. Note: Grapefruit and Seville oranges boost the effects of certain CCBs, sometimes to toxic levels. (Regular oranges do not appear to pose any hazard.)
Ranolazine (Ranexa) is used to treat chronic angina in patients who have not responded to other angina drugs. Ranolazine is taken in combination with amlodipine, beta blockers, or nitrates.
Angioplasty, also called percutaneous coronary intervention (PCI), involves procedures such as percutaneous transluminal coronary angioplasty (PTCA) that help open the blocked artery.
Angioplasty can help reduce the frequency of angina attacks for patients who have not been helped by drug therapy. It is commonly recommended for patients who have critically blocked arteries or have already had a recent, acute heart attack. Angioplasty can also help improve survival and prevent heart attacks in patients with acute coronary syndrome (ACS). However, doctors have been uncertain about angioplasty's benefits for survival and heart attack prevention in lower-risk patients with stable coronary artery disease.
Angioplasty works no better than standard heart medication (drugs to control blood pressure, lower cholesterol, and prevent blood clots) in preventing heart attack, stroke, and hospitalization in patients with stable coronary artery disease. Doctors now recommend angioplasty only for patients who have severe heart disease. For patients with stable heart disease, drug therapy may be sufficient enough treatment and allow them to safely defer having surgery.
Procedure. A typical angioplasty procedure follows these steps:
Complications occur in about 10% of patients (about 80% of them happening within the first day). Success rates are better in hospital settings with experienced teams and backup.
Recuperation and Complications. Angioplasty is less invasive than bypass surgery, requiring only one night in the hospital. Recuperation takes about a week. Chest pain after the procedure is very common and usually due to problems other than ischemia. Mild chest pain is even more common when a stent is used, possibly because the artery is stretched.
The most important short- and long-term complication of angioplasty is narrowing or reclosure (restenosis) of the artery, which can lead to heart attack if not treated with a repeat procedure. Stenting, anti-clotting drugs, and other advances have significantly helped prevent reclosure and reduce heart attack rates. Nevertheless, a repeat procedure is still needed to restore the opening in 10 - 15% of patients who have stents.
Drug-Coated Stents. Stents coated with the drugs sirolimus (Rapamune) or paclitaxel (Taxol) have been increasingly used in the last several years. Drug-eluting stents (as they are also called) can help prevent restenosis. However, because drug-eluting stents reduce arterial tissue growth, they can increase the risks of blood clots.
Recent studies indicate that drug-eluting stents are safe and effective for patients with coronary artery disease when they are used for FDA-approved indications. Some studies have indicated that problems may arise when these stents are used for “off-label” purposes in patients with more complicated health problems, although other studies have found no increased risks. There is still some concern that all stents (both bare metal and drug eluting) may be used too frequently for patients who may be better served by drugs or bypass surgery.
It is very important that all patients who have drug-eluting stents take aspirin and clopidogrel for at least 1 year after the stent is inserted to reduce the risk of blood clots. For patients undergoing PCI who have acute coronary syndrome, two newer antiplatelet drugs – prasugrel (Effient) or ticagrelor (Brilinta) – may be options. These drugs, like aspirin, help prevent blood platelets from clumping together. It is important that patients who have drug-eluting stents take both aspirin and another anti-platelet drug. If for some reason patients cannot stick to a dual anti-platelet regimen, they should receive a bare metal stent instead of a drug-eluting stent.
Coronary artery bypass graft surgery (CABG) is an alternative to angioplasty for many patients with severe coronary artery disease, but it is a very invasive open-heart surgical procedure.
Minimally invasive coronary artery bypass surgery (MIDCAB), also called “keyhole heart surgery,” may be an option for some patients. It uses various techniques, including endoscopy or robotic-assisted approaches. Unlike standard CABG, with MIDCAB patients do not have their heart stopped and do not have to be put on a heart-lung machine during the procedure. In MIDCAB, the surgeon uses a smaller incision on the left side of the chest. CABG requires a longer incision down the center of the chest.
In a traditional CABG procedure:
Complications. Complications are generally rare but can include bleeding, infections, heart attack, and stroke. Finding a surgeon who performs at least 100 of the procedures a year helps reduce the risk for complications.
Blood clots may form in the new graft, closing it up or narrowing the treated vessel over time. Therapy with aspirin and other anti-clotting drugs help keep the graft open and working properly.
Recuperation and Rehabilitation. After leaving the hospital, patients should have cardiac rehabilitation. Guidelines recommend that doctors refer patients who have had CABG or PCI to a comprehensive outpatient cardiac rehabilitation program. Rehabilitation includes education about healthy diet and lifestyle choices, as well as exercise training to rebuild strength and stamina.
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Review Date: 5/24/2012
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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