Over the past five years, new research has led to better ways to
prevent strokes in high-risk patients. These developments have
prompted researchers from the American Heart Association
(www.americanheart.org) to announce new guidelines for the
management of ``mini-strokes'' to help prevent future strokes.
The report appeared in the November issue of the journal Stroke
(www.strokeaha.org).
The occurrence of mini-strokes, also called transient ischemic
attacks, or TIA, makes a person 10 times as likely to have a stroke
in the future. Mini-strokes are caused by clots that block blood
flow to the brain. The main symptoms are sudden difficulty with
speech or vision, and weakness or tingling on one side of the body.
Mini-strokes typically last only 15 minutes but can last up to
24 hours, said Dr. John Marler, associate director for clinical
trials at the National Institute of Neurological Disorders and
Stroke (www.ninds.nih.gov) in Bethesda, Md. If the condition lasts
over 24 hours, it is then considered a stroke. A mini-stroke has
few noticeable long-term effects; a stroke can cause severe brain
damage.
The AHA recommends that after a mini-stroke, patients be treated
with medications called antiplatelet agents, which help thin the
blood. This group of drugs includes aspirin. Recent research shows
that even low doses of aspirin (50 milligrams per day) are
effective in preventing future strokes in mini-stroke patients.
Patients can use up to 325 milligrams of aspirin per day, but
evidence shows that those who have another mini-stroke while still
on aspirin will not benefit from increased dosages.
``There really is good supporting evidence for the lower dose of
aspirin,'' said Marler. ``It's better tolerated by patients, and if
it's widely used, it could have a significant reduction of stroke
incidence.''
``It used to be four aspirin (1,300 milligrams) a day were
required to prevent stroke after TIA,'' said Dr. Ralph Sacco,
associate chairman of neurology at the Neurological Institute at
Columbia University in New York and senior author of the report.
High doses of aspirin can cause gastrointestinal distress; also,
some patients do not benefit from the treatment. Newer antiplatelet
medications, specifically clopidogrel (Plavix, Bristol-Myers
Squibb/Sanofi Pharmaceuticals Partnership) and dipyridamole
(Persantine, Boehringer Ingelheim), a new drug that is usually used
in combination with aspirin, are useful for patients who cannot
tolerate aspirin well.
The report recommends that physicians treat patients with
antiplatelets before using anticoagulant medications like warfarin
(Coumadin, DuPont Pharma). However, for mini-stroke patients who
have a type of irregular heartbeat called atrial fibrillation,
evidence shows that long-term treatment with anticoagulants is
effective in preventing future strokes.
The authors also described how mini-stroke patients can take an
active role in reducing their chances of having another stroke:
Patients should bring their blood pressure down to 140/90; if
the patient has diabetes, blood pressure should be reduced to
130/85.
Patients should stop smoking; nicotine replacement therapies or
formal smoking-cessation programs should be used if necessary.
If the person has heart disease, irregular heart beat,
congestive heart failure or heart valve disorder, effective
treatment of these disorders can greatly reduce the risk of stroke.
Alcohol use should be limited to one or two drinks a day, levels
that have been shown to reduce stroke rates.
Patients should reduce their intake of fat, saturated fat and
cholesterol.
In addition, patients should try to keep their weight down and
exercise for 30 to 60 minutes, three to four times a week.
The authors of the paper also wrote that severe blockage of the
carotid artery, the artery in the neck that supplies blood to the
brain, may necessitate a surgery called carotid endarterectomy.
Patients who have a blood flow blockage of 70 percent or greater
are the primary candidates for this carotid-artery surgery,
although all patients with a 50 percent or greater blockage should
be considered candidates for the surgery, the report said. Other
patients should be treated with medication.
Sacco and his colleagues point out, however, that older persons,
women and those with diabetes are less likely to benefit from
carotid-artery surgery, and these factors should be taken into
consideration before doctors recommend surgery.
