Aspirin Taken Right After a Stroke May Prevent a Second One
June 1, 2000 -- Chalk another one up for aspirin: Researchers
have concluded that giving aspirin to stroke victims as soon as they arrive at
the hospital reduces their risk of having a second stroke.
In the first few days after having a stroke, patients are at
high risk of having another one, says Richard Peto, a professor at Oxford
University and co-author of an analysis published in the journal Stroke.
"We found that aspirin didn't do very much for repairing the damage done
already by the initial stroke, but ... it reduced the likelihood of having
another stroke in the hospital," he tells WebMD.
What's more, he says, it appears to be beneficial to give
aspirin to stroke victims right away even if doctors aren't 100% sure which
type of stroke the patient has had.
There are two kinds of strokes: ischemic stroke, caused by a
clot that blocks a blood vessel supplying the brain with blood, and hemorrhagic
or bleeding stroke, caused by a leaky blood vessel that bleeds into the brain.
A CT scan of the head can help a doctor determine if a stroke is the ischemic
or hemorrhagic type.
Aspirin, which thins the blood and thereby prevents clots, is
currently used to reduce the long-term risks of a second stroke in patients
who've had an ischemic stroke. But giving aspirin to patients who've had a
hemorrhagic stroke is considered dangerous, as it can cause more bleeding and
"Basically, doctors on the whole tend to wait for things to
settle down; they wait until they're sure of the diagnosis -- whether it is
ischemic or hemorrhagic," Peto says. "If you start aspirin a bit
earlier -- the first week or two is the time of highest risk -- it's the time
actually when aspirin is most protective. And what we have shown is that you
can safely start aspirin early on."
Peto and colleagues analyzed the results of two very large
studies, involving a total of 40,000 stroke patients, and found that compared
to patients who didn't get aspirin, a third fewer of the patients who received
aspirin had a recurrent stroke. Put another way, giving aspirin to 1,000 people
prevented about nine deaths or recurrent strokes.
Study author Zheng Ming Chen, MD, DPhil, of Oxford University,
says in a press release that preventing nine strokes or deaths out of 1,000
patients may not sound like much: "But if you consider there are several
million strokes worldwide each year, by treating one million of those with one
year of aspirin therapy, this will prevent about 20,000 strokes or
Even hemorrhagic stroke patients who were inadvertently given
aspirin did reasonably well, says Peto. "There were about 800 patients who,
in retrospect, had probably been misdiagnosed and they weren't any worse off
than patients who hadn't received aspirin.
"I think aspirin should become routine for suspected stroke
in the way that it is for suspected heart attack," he says. "What we
have shown is that ... the sooner you go ahead and act, the better, in terms of