Aspirin
does little or nothing for hard arteries, researchers find
University of Florida
For decades, aspirin
has been widely used to reduce the risk of cardiovascular problems.
Now, a team led by a
University of Florida Health researcher has found that aspirin may provide
little or no benefit for certain patients who have plaque buildup in their
arteries.
Aspirin is effective
in treating strokes and heart attacks by reducing blood clots.
The researchers
tracked the health histories of over 33,000 patients with atherosclerosis --
narrowed, hardened arteries -- and determined that aspirin is marginally
beneficial for those who have had a previous heart attack, stroke or other
blood-flow issues involving arteries.
However, among
atherosclerosis patients with no prior heart attack or stroke, aspirin had no
apparent benefit. The findings were published May 18 in the journal Clinical
Cardiology.
Because the findings
are observational, further study that includes clinical trials are needed
before definitively declaring that aspirin has little or no effect on certain
atherosclerosis patients, said Anthony Bavry, M.D., an associate professor in
the UF College of Medicine's department of medicine and a cardiologist at the
Malcom Randall Veterans Affairs Medical Center in Gainesville.
"Aspirin therapy is widely used and embraced by cardiologists and general practitioners around the world. This takes a bit of the luster off the use of aspirin," Bavry said.
Bavry said the
findings do not undercut aspirin's vital role in more immediate situations: If
a heart attack or stroke is underway or suspected, patients should still take
aspirin as a treatment measure.
"The benefit of
aspirin is still maintained in acute events like a heart attack or a
stroke," he said.
Among more than 21,000
patients who had a previous heart attack or stroke, researchers found that the
risk of subsequent cardiovascular death, heart attack or stroke was marginally
lower among aspirin users.
For those
atherosclerosis patients who had not experienced a heart attack or stroke,
aspirin appeared to have no effect.
The risk of
cardiovascular death, heart attack and stroke was 10.7 percent among aspirin
users and 10.5 percent for non-users.
Patients who enrolled
in the nationwide study were at least 45 years old with coronary artery
disease, cerebrovascular disease or peripheral vascular disease. Their medical
data were collected between late 2003 and mid-2009.
The researchers did
identify one group that got some benefit from aspirin -- people who had a
coronary bypass or stent but no history of stroke, heart attack or arterial
blood-flow condition.
Those patients should
clearly stay on an aspirin regimen, Bavry said. Bavry said discerning aspirin's
effectiveness for various patients is also important because the medicine can
create complications, including gastrointestinal bleeding and, less frequently,
bleeding in the brain.
Because of
insufficient data, the current study wasn't able to address the extent of
aspirin's role in bleeding cases.
"The cardiology
community needs to appreciate that aspirin deserves ongoing study. There are
many individuals who may not be deriving a benefit from aspirin. If we can
identify those patients and spare them from aspirin, we're doing a good
thing," he said.
The current findings
are the second time this year that Bavry and his collaborators have published
research about the apparent ineffectiveness of aspirin therapy.
In April, the group showed
that the drug may not provide cardiovascular benefits for people with
peripheral vascular disease, which causes narrowed arteries and reduced blood
flow to the limbs.
Bavry also cautioned
patients with atherosclerosis or peripheral vascular disease not to quit
aspirin therapy on their own. Instead, they should discuss the matter with
their physician, he said.
