Baby Aspirin May Not Prevent Stroke
Coated Aspirin Particularly Lacks Blood-Thinning Effect
Feb. 14, 2003 (Phoenix) -- Taking a daily aspirin is an easy
and well-known way to reduce the chances of having a heart attack and stroke,
but new research suggests that a "one-size-fits-all" approach to
aspirin therapy may not protect your heart or your brain.
"We noticed that a lot of people who have strokes or heart
attacks are taking daily aspirin. So we decided to look at why aspirin failed
to protect them," says Mark Alberts, MD, director of the stroke program at
Northwestern Memorial Hospital in Chicago.
One way that aspirin protects against heart attacks and strokes
is by preventing blood clots from forming, says Alberts. So he and his
colleagues decided to find out just how effective aspirin is as a blood thinner
in people taking daily doses.
The researchers tested blood samples from 126 people who were
taking different doses of daily aspirin. Thirty-nine patients took a baby
aspirin (81 mg) every other day, every day, or twice per day.
"We were surprised to find that more than half the people
taking baby aspirin didn't have their blood adequately thinned," he says.
Only 44% of people taking baby aspirin had the full blood-thinning benefit.
He reported his findings at the American Stroke Association's
28th International Conference.
Eighty-seven patients were taking a standard aspirin (325 mg)
every day or twice a day. With the higher dose, patients did better, with only
28% showing no blood-thinning effect.
Coated aspirin -- originally designed to help protect the
stomach -- was a particular concern. The researchers found that 65% of patients
taking coated aspirin were not receiving any blood-thinning benefit from the
aspirin. But 75% of people taking regular uncoated aspirin did, says
"I think these findings suggest that the one-size-fits-all
approach does not work for aspirin therapy," he says.
Larry B. Goldstein, MD, professor of medicine and director of
the Duke Center for Cerebrovascular Disease in Durham, N.C., tells WebMD the
important message for patients is that there have been a number of large
studies that found that aspirin does help prevent heart attacks and stroke and
that benefit is not related to dose. "The FDA-approved dose is 81 mg to 325
mg," Goldstein says.
He says, too, that aspirin is more than just a blood thinner.
"It has other effects, and we are not yet sure what how aspirin offers its
protection." Goldstein was not involved with the study.
Both Alberts and Goldstein did agree on this point: If you are
taking aspirin, don't change your dose without checking with your doctor.
"Aspirin is a powerful drug and needs to be taken carefully," says