Prevention

Forty percent of patients who have had a stroke or TIA will suffer a subsequent stroke within 5 years. In 2006, the American Heart Association / American Stroke Association released guidelines for preventing a second stroke. These guidelines recommend::

Quit Smoking. Also avoid exposure to second-hand smoke.

Maintain Weight. People should aim for a BMI index of 18.5 to 24.9. In people who are obese, reducing weight to this level can reduce the risk for stroke by 15% in men and 22% in women. Waist measurements should be no more than 35 inches for women and 40 inches for men.

Exercise. Everyone in normal health should engage in at least moderate physical activity for a minimum of 30 minutes on most -- if not all -- days of the week.

Limit alcohol. No more than 2 drinks a day for men and 1 drink a day for nonpregnant women.

Healthy Diet. Everyone should aim for a diet that contains a healthy balance of fruits, vegetables, grains, fish, nuts, legumes, poultry, lean meat, and low-fat dairy items. Avoid saturated fats and trans fatty acids.

Improve Cholesterol. People with at least two risk factors and a 10-year risk for heart disease or stroke of more than 20% should aim for LDL levels of less than 100 mg/dl. Raising HDL levels is important for people at risk for stroke. Statins are now used in most cases.

Keep Blood Pressure Low. People in normal health should aim for 139/89 mm Hg or less. Patients with certain health problems, such as diabetes, should aim lower.

Control Diabetes. People with diabetes should aim for fasting blood glucose levels of less than 110 mg/dl and hemoglobin A1C of less than 7%. Blood pressure goals should be 130/80 mm Hg or less.

Take Aspirin or Other Antiplatelet Therapy. People at high risk for heart disease should take a low-dose aspirin every day, unless they have medical reasons to avoid aspirin. (As an alternative to aspirin alone, your doctor may prescribe clopidogrel alone or aspirin plus extended release dipyridamole.) Aspirin may help to prevent strokes caused by blockage in the artery (ischemic stroke), but it may slightly increase the risk of strokes caused by bleeding in the brain (hemorrhagic stroke). A 2005 study found that low-dose aspirin may also help prevent stroke in healthy women over age 65. Current American Heart Association guidelines do not recommend that younger or low-risk women take daily aspirin for stroke and heart disease prevention.

Control Atrial Fibrillation. People with atrial fibrillation should use anticoagulants to reduce their risk of blood clots. Carotid Endarterectomy Surgery or Stenting: Recommended for most symptomatic patients with neck artery stenosis (narrowing or blockage) of more than 70% and some patients with stenosis of 50 – 69%.

Diet and Weight Control

A healthy diet rich in fruits and vegetables and low in salt and saturated fats may significantly lower the risk for both ischemic and hemorrhagic stroke.

Fruits and Vegetables. Studies suggest that people can protect their heart and circulation by eating plenty of fruits and vegetables. Eating at least five servings a day reduces blood pressure and protects against both heart attack and stroke. Important foods include most fruits (especially potassium-rich fruits including bananas, oranges, prunes, and cantaloupes) and vegetables (especially carrots, spinach, celery, alfalfa, mushrooms, lima beans, potatoes, avocados, broccoli). Vegetables, such as broccoli and kale, may be specifically protective against a first ischemic and possibly hemorrhagic stroke. Foods such as apples and tea, which are high in food chemicals called flavonoids, may also be very beneficial.

Whole Grains and Nuts. A 2000 study reported a lower incidence in stroke in women who had a high intake of whole-grain foods. Nuts may also be protective.

Calcium, Potassium, and Magnesium. Calcium, magnesium, and potassium serve as electrolytes in the body. They are important in controlling blood pressure and may also have protective effects against stroke:

Some evidence suggests that diets rich in potassium may protect against stroke by 22 - 40%, mostly by reducing blood pressure but also possibly because of other mechanisms. Low potassium levels may increase the risk for stroke in certain people.

A major study reported that calcium intake is associated with a lower risk for stroke in women, which supports an earlier study reporting a lower risk for stroke in men who drank more milk.

Magnesium deficiencies may increase the risk for atrial fibrillation. No evidence yet exists, however, that taking magnesium supplements is protective.

Salt Restriction. Although the effects of salt restriction are not entirely clear, a 2002 study indicated that even a modest reduction in salt intake for more than a month might reduce the risk of death from stroke by 14% in people with high blood pressure and 6% in people with normal blood pressure.

Fats and Oils. The effects of fats and oils on stroke are complex. One study indicated that middle-aged men without heart disease who had the highest intake of monounsaturated or saturated fat (but not polyunsaturated oils) also had the lowest risk for stroke. Monounsaturated oils, obtained in olive and canola oils, may have protective benefits against both heart disease and stroke. Saturated fats, found in animal products, are known risk factors for heart disease. Some studies suggest, however, that low intake of animal protein and saturated fat increases the risk of hemorrhagic stroke.

Other fat compounds that may be stroke protective are omega-3 fatty acids:

  • Alpha-linolenic acid is found in canola oil, soybeans, and walnuts. One particular benefit against stroke is its ability to help prevent the formation of blood clots.
  • Omega-3 fatty acids are categorized as docosahexaenoic (DHA) or eicosapentaneoic acids (EPA). They are found in oily fish and nutritional supplements. These compounds have anti-inflammatory and anti-blood clotting effects and may be significantly beneficial to the heart and reduce the risk for stroke. However, people who have implantable defibrillators should not take fish oil supplements because they may worsen heart rhythm problems.

In any case, consuming fish two or three times a week helps the heart.

Vitamins

Folic Acid and B Vitamins. 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. Researchers have been studying whether vitamin B supplements can reduce homocysteine levels and, consequently, heart disease risks.

Several major 2006 studies indicated that while B vitamin supplements help lower homocysteine levels, they have no effect on heart disease outcomes. The studies, published in the New England Journal of Medicine, examined patients who had either recently had a heart attack or suffered from diabetes or heart disease. Results showed a similar number of heart attacks and strokes among patients who took folic acid and B6 and B12 vitamins and those who received placebo. And, the vitamins seemed to increase risks for patients who had undergone stenting. Some experts think that homocysteine may be a marker for heart disease rather than a cause of it.

Antioxidant Vitamins. The effects of antioxidant vitamins and carotenoids on stroke have been studied extensively. Most studies have found that these vitamins do not help protect against stroke. An important 2001 study reported no protection from stroke with vitamins A or E or beta carotene. A 2005 study in the Journal of the American Medical Association found that vitamin E definitely does not protect women from stroke or heart attack.

Caffeine Intake, Alcohol, and Smoking

Smoking. Everyone should quit smoking.

Alcohol. Mild to moderate alcohol use (one to seven drinks a week) is associated with a significantly lower risk for ischemic stroke, although not hemorrhagic stroke. Heavy alcohol use, particularly a recent history of drinking, is associated with a higher risk of both ischemic and hemorrhagic stroke.

Coffee. In healthy people with normal blood pressure, drinking a couple of cups of coffee a day is unlikely to do any harm. Caffeine may actually have nerve-protecting properties that may help stroke survivors. Caffeine drinkers, however, might do better to choose tea, which may have beneficial nutrients, and people with existing hypertension should avoid caffeine altogether (since caffeine may increase the risk for stroke in this group).

Exercise

Exercise helps reduce the risk of atherosclerosis, which can help reduce the risk of stroke. Experts recommend at least 30 minutes of exercise on most, if not all, days of the week.

Lifestyle changes picture
Hypertension is a disorder characterized by chronically high blood pressure. It must be monitored, treated, and controlled by medication, lifestyle changes, or a combination of both.

Reducing Blood Pressure

Reducing blood pressure is essential in stroke prevention. Lifestyle measures such as exercise, weight loss, and healthy diets are important for everyone. Drug therapy is recommended for people with hypertension who cannot control their blood pressure through lifestyle changes. Many different types of drugs are used to control blood pressure. They include ACE inhibitors, angiotensin-receptor blockers, beta-blockers, calcium channel blockers, and diuretics. Some drugs, such as Hyzaar, combine an angiotensin receptor blocker with a diuretic to both treat high blood pressure and prevent stroke. [For more information, see In-Depth Report #14: High blood pressure.]

Lowering LDL and Raising HDL Cholesterol

In 2004, the National Cholesterol Education Program issued updated recommendations on how to control cholesterol levels. These guidelines emphasize that patients should lower their LDL (“bad”) cholesterol and recommend that more people take LDL-lowering medication. Lowering LDL cholesterol and raising HDL (“good”) cholesterol can significantly reduce the risks of heart disease, including stroke. Several different types of drugs (statins, bile-acid binding resins, niacin, and fibrates) are used to control cholesterol.

Statins are among the most important of these drugs. Brands include lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), fluvastatin (Lescol), atorvastatin (Lipitor), and rosuvastatin (Crestor). Research increasingly suggests that lowering LDL levels as much as possible is critical for preventing stroke and other heart disease problems. A major analysis of over 200 studies found that statins reduced the risk for heart problems by 60% and stroke by 17%. Another study of over 20,000 people with cerebrovascular disease found that patients who took statin therapy for 2 years reduced their risk of ischemic stroke by 25%. [For more information, see In-Depth Report #23: Cholesterol.]

Influenza Vaccinations (Flu Shots)

Influenza vaccinations may protect patients with a history of heart attack or heart events. A 2002 study further suggested that flu shots might protect against stroke, although possibly not in patients older than age 75.

Atrial Fibrillation and Its Treatments

Treatment for atrial fibrillation always includes drugs (aspirin or warfarin) to prevent clots from forming. In addition to anticoagulants (blood thinners), other approaches may include:

  • Restoring or maintaining normal heart rhythm. This is accomplished with anti-arrhythmic drug, cardioversion procedures, or surgery to remove the defective area.
  • Controlling heart rate. Specific drugs are used for this approach.

Important studies report that controlling heart rate may be the preferable approach. In several studies, rhythm control offered no survival advantages and did not protect against ischemic stroke. Therapies aimed at controlling heart rate, furthermore, had fewer complications.

Drugs to Prevent Blood Clots

After a diagnosis of atrial fibrillation, warfarin (an anticoagulant) or aspirin (an antiplatelet) are essential to prevent blood clots. These drugs can reduce the risk for stroke by over 60% in patients with atrial fibrillation.

  • Warfarin (Coumadin) is the main anticoagulant drug used to prevent strokes in high-risk patients with atrial fibrillation. Warfarin carries a risk for bleeding, but for most patients, warfarin’s benefits far outweigh its risks. Patients who are at risk for bleeding usually have a history of alcohol abuse, chronic kidney disease, or previous gastrointestinal bleeding.
  • Aspirin is less effective than warfarin, but has a lower risk for bleeding. It is the preferred treatment for younger people with atrial fibrillation and for people who do not have other risk factors for stroke such as high blood pressure or diabetes. Aspirin is also prescribed for higher risk patients who cannot tolerate anticoagulation therapy.
  • Researchers are investigating other drugs for preventing stroke and heart problems in patients with atrial fibrillation. These drugs include the antiplatelet medication clopidogrel (Plavix) and the angiotensin receptor blocker irbesartan (Avapro). Recent research indicates that anticoagulants such as warfarin (Coumadin) work better for atrial fibrillation patients than the combination of clopidogrel plus aspirin. Clinical trials are continuing to investigate whether clopidogrel alone is better than aspirin alone.

Restoring and Controlling Heart Rhythm

To initially restore heart rhythm, anti-arrhythmic drugs are usually tried first. If they fail to restore normal rhythm, cardioversion is often effective. (Some experts suggest trying cardioversion first to avoid side effects of the drugs.) Long-term maintenance therapy using anti-arrhythmic drugs may be required.

Electrical Cardioversion. Electrical cardioversion is mild shock therapy and is the current standard treatment used to restore normal heart rhythm. It is conducted as follows:

  • Anticoagulants (drugs used to prevent blood clotting) should be administered, if possible, at least 3 weeks before the procedure.
  • During the procedure, the patient must be conscious and, although sedated, can experience some pain from the procedure.

Although the stabilizing effect is usually only temporary, some evidence suggests that a series of cardioversion may succeed in maintaining normal rhythm in young healthy patients without the need for antiarrhythmic medications.

Low-energy implanted cardioverters (Atrioverter, Jewel AF) are being investigated for maintenance. Studies are promising.

Drugs Used for Maintaining Normal Heart Rhythm. For maintaining a stable rhythm, the following drugs may be used. The specific choices typically depend on whether the patient has existing heart disease or not:

  • For patients with no heart disease, the first choices include sotalol, flecainide, or propafenone, which are often used sequentially. If these fail, then amiodarone or a newer drug dofetilide (Tikosyn) may be tried. Others include ibutilide (Covert) and azimilide. If these drugs are not effective, other drugs tried include quinidine, procainamide, and disopyramide.
  • In patients with heart disease, amiodarone, dofetilide, or sotalol are commonly used depending on the cause of heart disease.

Amiodarone is more effective than most others and has been thought to be safer than many other similar drugs. Even in low doses, however, there is a high incidence of side effects, including thyroid disorders, neurologic, skin, and eye problems, and abnormally slow heart beats. Many of these drugs carry a small but significant increased risk, however, for a life-threatening arrhythmia called torsades de pointes. People with certain heart conditions should avoid these drugs.

Surgical Procedures for Complex AF. In some difficult cases, surgery may be recommended. The options and candidates depend on other complicating factors. The following are some examples:

  • AV node ablation involves severing the communication between the atria (the two upper chambers of the heart) and the ventricles (the two lower chambers). A pacemaker is then implanted just under the skin with electrodes leading to the ventricles. This approach is very effective, but it is irreversible and lifelong. Radiofrequency ablation may be an option in some patients.
  • A more aggressive procedure uses open chest surgery, in which a maze of cuts is made in the atria. As they heal, the scar tissue prevents the heart circuitry from misfiring. This technique controls atrial fibrillation in more than 90% of appropriate candidates. A new procedure is similar but less invasive.

Controlling Heart Rate

Drugs Used to Control Heart Rate. Beta-blockers or calcium channel blockers are used to control heart rate at the onset of atrial fibrillation. Digitalis, an older drug, is not used as often but can be effective in combination with the other drugs.