Atherosclerosis
Atherosclerosis
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Introduction:
Atherosclerosis is a slow disease in which your arteries become clogged and hardened. Fat, cholesterol, calcium, and other substances form plaque, which builds up in arteries. Hard plaque narrows the passage that blood flows through. That causes arteries to become hard and inflexible (atherosclerosis is also known as hardening of the arteries). It leads to cardiovascular disease, which is the leading cause of death in people over 45. Soft plaque is more likely to break free from the artery wall and cause a blood clot, which can block blood flow to vital organs.
The effects of atherosclerosis differ depending upon which arteries in the body narrow and become clogged with plaque. If the arteries that bring oxygen-rich blood to your heart are affected, you may have coronary artery disease, chest pain, or a heart attack. If the arteries to your brain are affected, you may have a transient ischemic attack (TIA) or a stroke. If the arteries in your arms or legs are affected, you may develop peripheral artery disease. You may also develop a bulge in the artery wall (aneurysm).
Lowering blood pressure and LDL ("bad") cholesterol levels, eating a healthy diet with lots of fruits and vegetables, quitting smoking, losing weight, and getting more exercise can prevent atherosclerosis.
Signs and Symptoms:
Many times, people with atherosclerosis have any symptoms until an artery is 40% clogged with plaque. Symptoms vary depending upon which arteries are affected.
Coronary Artery Disease
Symptoms of coronary artery disease (where the heart arteries are narrowed) are usually brought on by physical exercise, sexual activity, exposure to cold weather, anger, or stress. The most common symptoms include:
Chest pain (generally a heavy, squeezing, or crushing sensation with possible burning or stabbing pains)
Abdominal, neck, back, jaw, or shoulder/arm pain
Weakness
Perspiration
Shortness of breath
Cerebrovascular Disease
Cerebrovascular disease (where the arteries that supply the brain with blood) are narrowed) can cause transient ischemic attack (a sudden loss of brain function with complete recovery within 24 hours) and stroke. Symptoms may include:
Weakness or paralysis on one side of the body
Trouble speaking or understanding speech
Loss of vision in one eye
Muscle weakness
Sudden trouble walking
Dizziness
Loss of balance or coordination
Sudden severe headache
Peripheral Artery Disease
Peripheral artery disease affects the arteries that supply the arms and legs with oxygen-rich blood. Symptoms may include:
Pain, aching, cramps, numbness or sense of fatigue in the leg muscles (intermittent claudication)
"Bruits" (blowing sounds your doctor can hear with a stethoscope that indicate turbulence in blood flow)
Hair loss
Thickened nails
Smooth, shiny skin surface
Skin that is cold to the touch
Gangrene
What Causes It?:
No one knows the exact cause of atherosclerosis, although they do know what causes it to get worse. Many researchers believe it begins with an injury to the innermost layer of the artery, known as the endothelium. These factors are thought to contribute to the damage:
High blood pressure
Elevated LDL ("bad") cholesterol
An accumulation of homocysteine (an amino acid produced by the human body, thought to be a risk factor for heart disease, stroke, osteoporosis, diabetes, and dementia)
Smoking
Diabetes
Inflammation
Once the artery is damaged, blood cells called platelets build up there to try and heal the injury. Over time, fats, cholesterol, and other substances also build up at the site, which thickens and hardens the artery wall. The blood flow through the artery is decreased, and the oxygen supply to organs also decreases. Blood clots may form, blocking the artery or entering your bloodstream and cut off blood supply to other organs.
Because some people do not have the classic risk factors of atherosclerosis (such as cigarette smoking and high blood pressure), it is possible that there may be other causes, such as an infection. Research is ongoing.
Risk Factors:
Risk factors for atherosclerosis include:
Being male
If female, being past menopause
High blood pressure
High LDL ("bad) cholesterol or triglycerides (fats in the blood)
Diabetes
Being overweight
Smoking
A family history of heart disease
Elevated homocysteine levels
Sedentary lifestyle
Diets high in saturated fat and trans fatty acids (trans fats)
Depression
What to Expect at Your Provider's Office:
Your doctor can determine your risk for heart disease by conducting some tests. Blood tests can show high levels of cholesterol, homocysteine, and blood clotting factors. A stress test (also known as an exercise tolerance test) monitors your heart rate and blood pressure while you walk on a treadmill or ride a stationary bicycle. An electrocardiogram (ECG) is used during a stress test to detect abnormal heart rhythms, scar tissue in the heart muscle from a prior heart attack, and areas of decreased blood flow to the heart. Imaging techniques used during a stress test (such as an ultrasound) can pinpoint areas where blood flow to the heart may be decreased. An angiogram (or angiography), where your doctor injects a dye into your arteries and then performs a chest x-ray, can reveal areas of damage and plaque buildup.
Preventive Care:
You can prevent atherosclerosis by living a healthy lifestyle.
Stop smoking.
Exercise at least 30 minutes a day, 6 days a week.
Eat healthy foods, such as fruits, vegetables and whole grains that are low in saturated fat and high in fiber.
Maintain a normal weight (or lose weight if you need to).
Reduce stress.
If you have high blood pressure, high cholesterol, diabetes or another chronic condition, work with your doctor to keep it in check.
Treatment Options:
Healthy lifestyle choices (see "Preventive Care" section) are important in preventing and treating atherosclerosis. Your doctor may prescribe drugs to lower your cholesterol or blood pressure and to prevent complications. Nutrition and dietary supplements can help when used along with certain medications. Some herbs have also shown promise in lowering cholesterol levels and reducing the risk of heart disease.
Drug Therapies
Cholesterol-Lowering Drugs
If, after making adjustments to your diet and exercise habits, your "bad" LDL cholesterol remains high, your doctor may prescribe medications to lower it. If your cholesterol is extremely high (more than 200 mg/dL), you may start drug therapy at the same time you make lifestyle changes. Drugs commonly used to treat high cholesterol include:
Statins -- These are usually the drugs of choice as they are easy to take and have few interactions with other drugs. Side effects can include myositis (inflammation of the muscles), joint pain, stomach upset, and liver damage. People who are pregnant or have liver disease should not take statins. Statins include:
Lovastatin (Mevachor)
Pravastatin (Pravachol)
Rosuvastatin (Crestor)
Simvastatin (Zocor)
Atorvastatin (Lipitor)
Fluvastatin (Lescor)
Niacin (nicotinic acid) -- In prescription form, niacin is sometimes used to lower LDL cholesterol. It can be more effective in raising HDL cholesterol than other medications. Side effects may include redness or flushing of the skin (which can be reduced by taking aspirin 30 minutes before the niacin), stomach upset (which usually subsides in a few weeks), headache, dizziness, blurred vision, and liver damage. Dietary supplements of niacin should not be used instead of prescription niacin, as it can cause side effects. Only take niacin for high cholesterol with your doctor's supervision.
Bile acid sequestrants -- These are used to treat high levels of LDL. Common side effects include bloating, constipation, heartburn, and elevated triglycerides. People who have high levels of triglycerides (fats in the blood) should not take bile acid sequestrants. These drugs include:
Cholestyramine (Prevalite, Questran)
Colestipol (Colestid)
Colesevelam (WelChol)
Cholesterol absorption inhibitors -- The medication ezetimibe (Zetia) limits how much LDL cholesterol can be absorbed in the small intestine. Side effects include headaches, nausea, muscle weakness. Ezetimibe is combined with simvastatin in the drug Vytorin.
Fibric acid derivatives -- These medicines are effective at lowering triglyceride levels, and moderately effective at lowering LDL. They are used to treat high triglycerides and low HDL in people who cannot take niacin. Side effects include myositis, stomach upset, sun sensitivity, gallstones, irregular heartbeat, and liver damage.
Gemfibrozil (Lopid)
Fenofibrate (Tricor, Lofibra)
If you do not respond to one class of drugs, you doctor may use a combination of drugs from two classes.
Blood Pressure-Lowering Drugs
If, after making adjustments to your diet and exercise habits, your blood pressure remains high, your doctor may prescribe medications to lower it. Among the drugs used to lower blood pressure are:
Beta blockers -- slow down the heart rate (reducing the workload on the heart) and reduce stress hormones in the body (which allows blood vessels to relax). Beta blockers alone don't work as well in African-Americans, but are effective when combined with a thiazide diuretic. Beta blockers include
Atenolol (Tenormin)
Bisoprolol (Zebeta)
Metoprolol (Lopressor, Toprol XL)
Nadolol (Corgard)
Timolol (Blocadren)
Nebivolol (Bystolic)
Angiotensin-converting enzyme (ACE) inhibitors -- block the chemical angiotensin from forming in the body, helping prevent blood vessels from narrowing. As blood vessels relax, blood pressure is lowered. Like beta blockers, ACE inhibitors along don't work as well in African-Americans, but are effective when combined with a thiazide diuretic.ACE inhibitors include:
Captopril (Capoten)
Benazepril (Lotensin)
Enalapril (Vasotec)
Lisinopril (Prinivil, Zestril)
Fosinopril (Monopril)
Ramipril (Altace)
Perindopril (Aceon)
Quinapril (Accupril)
Moexipril (Univasc)
Trandolapril (Mavik)
Calcium-channel blockers -- relax blood vessels and lower blood pressure by blocking calcium from entering heart cells and arteries. Side effects may include constipation, nausea, and headache. Grapefruit juice interacts with some calcium-channel blockers, so avoid it if you take these drugs. Calcium-channel blockers include:
Amlodipine (Norvasc)
Bepridil (Vascor)
Diltiazem (Cardizem)
Felodipine (Plendil)
Nifedipine (Adalat, Procardia)
Nicardipine (Cardene)
Verapamil (Calan, Isoptin)
Angiotensin II receptor blockers (ARBs) -- block the effects of the chemical angiotensin in the body, lowering blood pressure. ARBs are sometimes used when a person cannot take ACE inhibitors. These drugs include:
Candesartan (Atacand)
Eprosartan (Tevetan)
Irbesartan (Avapro)
Losartan (Cozaar)
Telmisartan (Mycardis)
Valsartan (Diovan)
Diuretics -- help the kidneys get rid of sodium and water from the body. This decreases the volume of blood in the body and lowers blood pressure. There are three types of diuretics: thiazide, loop, and potassium-sparing.
Thiazide diuretics -- may lower potassium levels and may increase cholesterol and blood sugar. Hydrocholorothiazide is the most common of these.
Loop diuretics -- also tend to lower potassium levels. Furosemide (Lasix) and bumetanide (Bumex) are loop diuretics.
Potassium-sparing diuretics -- do not lower potassium. Amiloride (Midamor) and triamterene (Maxzidel) are in this class.
Sometimes drugs from these classes may be combined.
Blood-Thinning Drugs
Blood-thinning drugs -- antiplatelet agents and anticoagulants -- are used to keep blood clots from forming.
Aspirin -- reduces risk of transient ischemic attack (TIA), stroke, and heart attacks
Ticlodipine -- for people who cannot take aspirin (due to allergies, for example) or do not improve from aspirin; has more side effects than aspirin
Dipyridamole -- not as effective as aspirin when used alone but may be used in combination with aspirin or warfarin (another blood thinner)
Clopidogrel (Plavix) -- reduces risk of heart attacks
Glycoprotein IIb/IIIa receptor agonists (such as abciximab, eptifibatide, lamifiban, and tirofiban) -- used when awaiting or just following an angioplasty
Heparin -- anticoagulant; given by injection
Warfarin (Coumadin) -- often used after a heart attack
Surgery and Other Procedures
Several different procedures (surgical and non-surgical) may be performed depending upon which arteries are narrowed and how much they are blocked.
Non-surgical techniques
Angioplasty -- used to widen narrowed arteries. A surgeon inserts a catheter with a deflated balloon into the narrowed part of the artery. The balloon is inflated, widening the blood vessel so blood can flow more easily. The balloon is then deflated, and the catheter is removed. A permanent stent (wire mesh) may be put in to hold the artery open and improve blood flow.
Atherectomy -- a procedure to remove plaque from the arteries. It uses a laser catheter or a rotating shaver.
Surgical Procedures
Bypass surgery -- A surgeon uses a blood vessel from another part of your body or an artificial tube to reroute blood around clogged arteries.
Minimally invasive bypass surgery -- uses a small incision rather than the broad opening in the chest wall created during regular bypass surgery.
Endarterectomy -- used to remove plaque in the carotid (neck) or peripheral arteries.
Complementary and Alternative Therapies
Nutrition and Supplements
Healthy eating habits can help reduce high cholesterol, high blood pressure, and overweight -- three of the major risk factors for heart disease. The American Heart Association (AHA) has developed dietary guidelines that help lower fat and cholesterol intake and reduce the risk of heart disease. The AHA does not recommend very low-fat diets because research shows that people benefit from unsaturated ("good") fats, such as those found in olive oil, in their diet.
Many fad diets are popular, but they may not help you lose weight and keep it off -- and in some cases, they may not even be healthy. Any healthy diet will include a variety of foods. If a diet bans an entire food group (such as carbohydrates), it's probably not healthy.
For healthy eating, eat a balanced diet that contains the following:
Grains: 6 - 8 servings per day (half should be whole grains)
Vegetables: 3 - 5 servings per day
Fruits: 4 - 5 servings per day
Fat-free or low-fat dairy: 2 - 3 servings per day
Lean meat, poultry, seafood: 3 - 6 oz. per day (about the size of a deck of cards)
Fats and oils: 2 - 3 tbsp. per day (use unsaturated fats such as olive oil or canola oil)
Nuts, seeds, legumes: 3 - 5 servings per week
Sweets, sugars: 5 or fewer servings per week (the fewer, the better)
In addition, the AHA also recommends eating 2 servings of fatty fish (such as salmon or lake trout) per week; holding sodium (salt, including salt already added to food) to less than 2,400 mg per day; and limiting alcohol intake to one drink a day for women and two for men.
Diets for People with High Blood Pressure
People with high blood pressure especially need to lower the amount of sodium in their diet. The DASH diet (Dietary Approaches to Stop Hypertension) emphasizes a diet rich in fruits, vegetables, and low-fat or non-fat dairy products that provide high intake of potassium, magnesium, and calcium sources. Sodium intake should be between 1,500 - 2,400 mg per day (the lower, the better). Weight loss, regular physical activity, and limiting alcohol are also very important factors for lowering blood pressure.
Mediterranean Diet
The Mediterranean style diet concentrates on whole grains, fresh fruits and vegetables, fish, olive oil, and moderate, daily wine consumption. The Mediterranean style diet is not low-fat. Instead, it is low in saturated fat but high in monounsaturated fat. It appears to be heart-healthy: In a long-term study of 423 patients who had a heart attack, those who followed a Mediterranean style diet had a 50 - 70% lower risk of recurrent heart disease compared with people who received no special dietary counseling.
The TLC (Therapeutic Lifestyle Changes) Diet
This diet is recommended for people who have high cholesterol. With the TLC diet, less than 7% of your daily total calories should come from saturated fat, and only 25% -35% of your daily calories should come from fat, overall. Sodium should be limited to 2,400 mg per day. If these steps don't lower your cholesterol, your doctor may suggest adding more soluble fiber to your diet, along with plant sterols (found in cholesterol-lowering margarines and salad dressings).
Supplements and Vitamins
Talk with your doctor before taking any of these vitamins, minerals, or supplements to make sure they are right for you; to establish the proper dose for your condition; and to make sure they do not interact with any prescription drugs, or herbs or supplements you also might be taking.
Folic acid (400 mcg per day), vitamin B6 (25 - 100 mg per day), vitamin B12 (2 - 100 mcg per day) -- The B vitamins help the body break down homocysteine, an amino acid that's been linked to increased risk of heart disease and stroke. Researchers think that homocysteine may also contribute to atherosclerosis by damaging artery walls, thus causing blood clots to form -- but so far they haven't found a definite link. Researchers also don't yet know whether taking B vitamins reduces the risk of atherosclerosis or heart disease, nor do they know how much might have an effect. If you have a number of risk factors for heart disease, talk to your doctor about checking your homocysteine levels and whether your doctor would recommend a B complex vitamin supplement. In the meantime, be sure to get enough B vitamins through your diet by eating fruits and leafy green vegetables every day.
Omega-3 fatty acids, found in fish oil (1 - 4 g per day) -- There is good evidence that omega-3 fatty acids (namely EPA and DHA) found in fish oil can help prevent and treat atherosclerosis by preventing the development of plaque and blood clots. Omega-3s can also help prevent heart disease, lower blood pressure, and reduce the level of triglycerides (fats) in the blood. One preliminary study found that people with high cholesterol who took fish oil and red yeast rice lowered cholesterol levels about as much as people who took simvastatin (Zocor). The AHA recommends that people eat at least two servings of fatty fish (such as salmon) per week. People with heart disease or those who need to lower triglycerides may need to take fish oil supplements. Because fish oil at high doses can increase the risk of bleeding, talk to your doctor before taking a high dose (more than 1 g per day), especially if you already take blood-thinning medication.
Beta-sitosterol (800 mg to 6g per day in divided doses about 30 minutes before meals) -- Beta-sitosterol is a plant sterol, a compound that can stop cholesterol from being absorbed by the intestines. A number of well-designed scientific studies have shown that beta-sitosterol does lower "bad" LDL cholesterol levels in the body. Beta-sitosterol may lower the amount of vitamin E and beta-carotene absorbed by the body, so you may want to ask your doctor if you need to take extra E or beta-carotene.
Potassium -- Your body needs potassium to keep electrolytes balanced and for nerves to function properly. Some diuretics may cause the body to get rid of too much potassium. If you take a prescription diuretic, your doctor may also recommend a potassium supplement. But be sure to check with your doctor before taking a potassium supplement if you take a diuretic. High levels of potassium can be dangerous.
Policosanol (5 - 10 mg two times per day) -- Policosanol is a mix of waxy alcohols usually derived from sugar cane and yams. Several studies have indicated it may lower "bad" LDL cholesterol and possibly even raise "good" HDL cholesterol. One study found that policosanol was equivalent to fluvastatin (Lescol) and simvastatin (Zocor) in lowering cholesterol levels. It may also stop blood clots from forming. However, most studies have been conducted in Cuba by a research group that uses a proprietary form of policosanol and is funded by the manufacturer, so it is hard to evaluate the evidence. Policosanol may increase the risk of bleeding, and should not be taken by people who also take blood-thinning medication.
Antioxidant vitamins (beta-carotene, C, E) -- Some large, observational studies have suggested that people who consume more antioxidant vitamins have a lower risk of heart disease than those who consumer lower amounts. However, no studies have shown a cause-and-effect relationship.
Beta-carotene -- While some studies suggest that eating a diet high in beta-carotene (found in yellow, orange, and dark green vegetables) may protect against atherosclerosis, other studies show it may increase the risk for people who smoke or drink a lot of alcohol. Researchers think that eating vegetables with beta-carotene also provides the body with other antioxidants that may have the protective effect, while just taking a supplement does not.
Vitamin C -- Several studies suggest that eating a diet high in vitamin C can help protect against heart disease. But there is no evidence that taking extra vitamin C through a supplement will help.
Vitamin E -- One randomized, placebo-controlled study failed to show any reduction in heart disease among people who took vitamin E. However, researchers are still studying the effects of vitamin E on heart disease risk.
Selenium (100 - 200 mcg per day) -- Some studies show that people who consume more selenium in their diet have a lower risk of heart disease, but again, researchers haven't shown a cause-and-effect relationship. And one study found that taking selenium for a long time significantly increased the risk of developing type 2 diabetes. Talk to your doctor before taking extra selenium.
Coenzyme Q10 (CoQ10) -- Researchers believe that CoQ10 may inhibit blood clot formation and boost levels of antioxidants. One study found that people who received daily CoQ10 supplements within 3 days of a heart attack were much less likely to experience subsequent heart attacks and chest pain. They were also less likely to die of the condition than those who did not receive the supplements. Still, more research is needed to say whether CoQ10 has any role in preventing or treating atherosclerosis. People who take statins may have lower amounts of CoQ10 in their bodies and may consider taking a supplement. If you take statins, ask your doctor if you need a CoQ10 supplement.
Polyphenols -- Polyphenols are chemical substances found in plants that have antioxidant properties. Test tube, animal, and some population-based studies suggest that the flavonoids quercetin, resveratrol, and catechins (all found in high concentration in red wine) may help reduce the risk of atherosclerosis by protecting against the damage caused by LDL cholesterol. However, more studies in humans are needed to confirm these findings.
One study of resveratrol in mice found that it protected against age-related damage to vital organs, including the heart and liver, even when the mice ate a high-fat diet. Although this study is promising, researchers need to confirm its findings and to see whether resveratrol would have the same effect in humans. No one is sure how much resveratrol you would need to see if there is any benefit. In addition, resveratrol may have estrogen-like effects, and researchers don't yet know whether it would pose the same risks as estrogen supplements.
Vitamin D -- Some preliminary studies suggest that vitamin D may also help protect against heart disease, but researchers aren't sure why. One observational study found that women over the age of 65 who took vitamin D supplements to protect against osteoporosis had one-third less risk of dying from heart disease as women who did not take the supplements. And a recent study found that a vitamin D deficiency was associated with an increased risk of heart disease, especially among people with high blood pressure.
Herbs
Hawthorn (Crataegus monogyna, 160 - 1,800 mg per day in two or three divided doses) -- Hawthorn contains the polyphenols rutin and quercetin, and was used traditionally to treat cardiovascular diseases. Animal and laboratory studies show that hawthorn has antioxidant properties that help protect against the formation of plaques and may help lower high cholesterol and high blood pressure. Talk to your doctor before taking hawthorn, as it can interact with other drugs taken for heart disease and high blood pressure.
Garlic (Allium sativum, 900 mg per day of garlic powder, standardized to 0.6% allicin) -- Some clinical trials have shown that fresh garlic and garlic supplements may lower cholesterol levels, prevent blood clots, and destroy plaque. However, other studies show mixed evidence, and one 2007 study showed no effect at all. Garlic can increase the risk of bleeding and should not be taken if you are also taking blood-thinning medication.
Olive leaf extract(Olea europaea, 1000 mg per day) -- One study found that people with mild high blood pressure (hypertension) lowered cholesterol and blood pressure by taking olive leaf extract, compared to those who took placebo. More research is needed to confirm this study's findings.
Red yeastor red yeast rice (Monascus purpureus, 1,200 mg two times per day with meals) -- Several studies indicate that a proprietary form of red yeast (Cholestin) can lower cholesterol levels, and that the herb acts like the prescription drugs statins (See "Medications" section). For that reason, you should not take red yeast without a doctor's supervision, especially if you already take statins to lower cholesterol.
Psyllium (Plantago psyllium, 10 - 30 g per day in divided doses taken 30 - 60 minutes after meals) -- Taking psyllium, a type of fiber, helps lower cholesterol levels as well as blood sugar levels. If you take medicine for diabetes, talk to your doctor before taking psyllium.
Guggul (Commiphora mukul, 3 - 6 g per day) -- Guggul is used in Ayurvedic medicine to treat high cholesterol levels. Scientific studies have found mixed results -- guggul appears to work in Indian populations, but not in people who eat Western-style, high-fat diets.
Acupuncture
Acupuncture may help reduce risk factors for heart disease. It can help people who want to quit smoking. Some studies indicate that it may aid in weight loss as well as lowering cholesterol and blood pressure.
Homeopathy
Although few studies have examined the effectiveness of specific homeopathic remedies, professional homeopaths would recommend appropriate treatments to reduce the risk of atherosclerosis based on their knowledge and experience. Homeopathic prescriptions for atherosclerosis would include remedies to lower high blood pressure and cholesterol. Before prescribing a remedy, homeopaths take into account a person's constitutional type. In homeopathic terms, a person's constitution is his or her physical, emotional, and intellectual makeup. An experienced homeopath would assess all of these factors when determining the most appropriate remedy for each individual.
Other Considerations:
Prognosis and Complications
Some complications of atherosclerosis include:
Heart disease
Heart failure
Abnormal heart rhythms
Stroke
Heart attack
Poor blood supply to certain parts of the body (such as the legs or intestines)
Kidney failure
Death
The outlook for atherosclerosis varies from person to person. People with atherosclerosis should work closely with their doctor to make the right lifestyle changes and, if needed, take the proper medications to control their condition and avoid complications.
Alternative Names:
Arteries - hardening of; Arteriosclerosis; Coronary artery disease
Reviewed last on: 12/13/2008
Steven D. Ehrlich, NMD, private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network
UMMC is a member of the University of Maryland Medical System, 22 S. Greene Street, Baltimore, MD 21201. TDD: 401.328.9600 or 1.800.492.5538
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