Higher Aspirin Doses May Protect Recurrent Strokes

Stroke survivors who take aspirin and havestroke recurrence in some, but not all, stroke
elevated blood levels of cholesterol and other lipidssurvivors.
may need to take higher doses of aspirin to"It provides another piece of the puzzle as to
prevent a second brain attack, a new study finds.why some people fail with aspirin," says Helgason.
Vadim Karepov, M.D., Ph.D., and his colleagues at"It suggests that some are not taking the right
the Tel Aviv Medical Center in Israel, examineddoses and that there might be a particular dose
the patient profiles of 3,140 consecutive strokefor a particular person."
patients, 2,239 of whom had a first ischemicKarepov is one of a team of researchers involved
stroke, and 901 of whom had experienced ain the Tel Aviv Stroke Study, a project focusing
second ischemic stroke. They found that aspirinon stroke prevention
failed to act in 126 of the 2,239 with a firstIn the study Karepov explored causes of aspirin
stroke and 157 of the 901 with a second stroke.failure, including age, ischemic heart disease,
Aspirin doses in these patients ranged from 100cholesterol and lipid levels and inadequate aspirin
to 1,000 milligrams (mg) daily.dose. The 3,140 men and women who
An ischemic stroke is one caused by a reductionparticipated in the trial were grouped according to
or cessation of blood flow, usually resulting from awhether they had had one or more strokes and
clot that plugs up an artery that feeds blood toif they had taken aspirin regularly as a preventive
the brain.treatment
The researchers found that individuals who haveHyperlipidemia and aspirin dose were the only
hyperlipidemia (elevated cholesterol and otherstriking links to aspirin failure. Among patients who
lipids) were most prone to aspirin failure and mighthad suffered a single stroke, hyperlipidemia was
benefit from higher doses than typically usedassociated with aspirin failure in 23 percent of
(aspirin doses usually range from 125 - 1,000 mgcases. Hyperlipidemia was present in only 7.8
daily).percent of patients who responded to aspirin.
Karepov presented these results today at theSimilar trends were found among patients with
AHA's 21st International Joint Conference onrecurrent strokes. Hyperlipidemia was observed in
Stroke and Cerebral Circulation.14 percent of the aspirin-failed group versus 6.4
"Our results show a possible way of preventing apercent of those whom aspirin did not fail.
second stroke in these patients who will require"We have seen that aspirin prevents mortality
higher doses or other aggressive therapy," saysand severity of recurrent strokes, but it is less
Karepov, noting that the effectiveness of aspirineffective in patients with such ischemic heart
increased with doses of 350 mg/day or more.disease risk factors as hyperlipidemia. These
Aggressive therapy in such cases could includepatients need more aggressive therapy or bigger
such actions as: higher aspirin doses; use of thedoses," concludes Karepov.
drug Ticlid (which keeps platelets -- blood- clottingAlthough aspirin has been used for about 15 years
components -- from sticking together); treatmentas preventive therapy against second strokes, it
with anticoagulants; and combination drug therapy,averts only about 25 percent of recurrent
Karepov says.strokes. Aspirin also has not been shown
Cathy Helgason, M.D., professor of neurology ateffective against first strokes, according to
the University of Illinois College of Medicine inKarepov.
Chicago, comments that the Tel Aviv study'sStroke is the third leading cause of death and the
results were consistent with other researchleading cause of serious disability in the United
showing that aspirin is effective in preventingStates.