Anticoagulant Agent Superior in International PREVAIL Study

Anticoagulant Agent Superior in International PREVAIL Study

February 10, 2007

    SAN FRANCISCO, Feb. 10 /Xinhua-PRNewswire/ -- A
1,700-patient study comparing anticoagulation therapies
found that enoxaparin, one of a class of compounds called
low-molecular-weight heparins, is significantly more
effective than an older therapy at preventing a dangerous
and common ischemic stroke complication called venous
thromboembolism (VTE).

    Importantly, patients benefited even when the treatment
was not initiated for up to two days following the onset of
ischemic stroke symptoms. "These results are extremely
useful for practitioners to know that they have a relatively
long therapeutic window to start prophylaxis following the
diagnosis of ischemic stroke," said neurologist David
Sherman, M.D., professor of medicine at The University of
Texas Health Science Center at San Antonio. 

    Dr. Sherman is principal investigator for the
international PREVAIL study (Prevention of VTE after Acute
Ischemic Stroke with Low-Molecular-Weight Heparin
Enoxaparin). He presented the findings today at the 2007
International Stroke Conference in San Francisco. The
research was sponsored by Sanofi-Aventis, maker of
Lovenox(R), brand name for enoxaparin.

    Ischemic stroke, caused by a blood vessel blockage, is
by far the most common type of stroke (about 85 percent of
cases). VTE, a general term used to describe the formation
of a blood clot (thrombus) that blocks a vessel, is
diagnosed for the first time in an estimated 300,000
Americans each year.

    The PREVAIL study enrolled 1,762 patients in 15
countries who suffered ischemic stroke. Participants were
enrolled within 48 hours of the onset of ischemic stroke
symptoms. They were randomly assigned to be treated with
either enoxaparin or the older class of agent,
unfractionated heparin, for 10 days and were followed for
90 days.

    Enoxaparin reduced the relative risk for developing VTE
after an acute ischemic stroke by 43 percent versus
unfractionated heparin (10.2 percent of participants in the
enoxaparin arm of the study developed VTE, versus 18.1
percent of participants in the unfractionated heparin arm).


    Results showed that this significant reduction of VTE
risk with enoxaparin versus unfractionated heparin was
maintained whether the treatment was initiated within 24
hours of stroke symptom onset or whether it was initiated
24 to 48 hours after symptom onset. 

    Among participants receiving enoxaparin within 24 hours
of symptom onset, 8.1 percent suffered VTE. Among those
receiving unfractionated heparin within 24 hours, the
figure was 18.5 percent. Among participants receiving
enoxaparin after 24 to 48 hours, 11.3 percent suffered VTE.
Among those receiving unfractionated heparin after that
duration, the figure was 17.8 percent.

    This relative risk reduction was associated with a
comparable safety profile as assessed by no significant
difference in clinically important bleeding, whatever the
time of initiation (within 48 hours after stroke onset). 

    Furthermore, the clinical benefit of enoxaparin on VTE
prevention did not affect stroke patient outcomes at three
months as compared to unfractionated heparin. Rate of
stroke progression and stroke recurrence were comparable in
both groups.

    The University of Texas Health Science Center at San
Antonio is the leading research institution in South Texas
and one of the major health sciences universities in the
world. With an operating budget of $536 million, the Health
Science Center is the chief catalyst for the $14.3 billion
biosciences and health care industry, the leading sector in
San Antonio's economy. The Health Science Center has had an
estimated $35 billion impact on the region since inception
and has expanded to six campuses in San Antonio, Laredo,
Harlingen and Edinburg. More than 22,000 graduates
(physicians, dentists, nurses, scientists and allied health
professionals) serve in their fields, including many in
Texas. Health Science Center faculty are international
leaders in cancer, cardiovascular disease, diabetes, aging,
stroke prevention, kidney disease, orthopaedics, research
imaging, transplant surgery, psychiatry and clinical
neurosciences, pain management, genetics, nursing, allied
health, dentistry and many other fields.  For more
information, click on http://www.uthscsa.edu .


    For more information, please contact:

    The University of Texas Health Science Center
     Will Sansom
     Tel: [phone]

     Lucie Portela
     Tel: [phone] 


SOURCE  The University of Texas Health Science Center