OASIS 5 Trial shows fondaparinux may be an effective anti-thrombotic drug in many patients with acute coronary syndrome already on aspirin and clopidogrel
The OASIS 5 Trial suggests that fondaparinux
may be at least as effective as an anti-thrombotic drug as enoxaparin
for many patients with acute coronary syndrome already on aspirin
and clopidogrel, according to a presentation at the annual meeting
of the European Society of Cardiology.
The Organization to Assess Strategies for
Ischaemic Syndromes (OASIS 5) trial is the largest to date to study
therapies for patients with acute coronary syndrome and enrolled
more than 20,000 patients. In the comparison of fondaparinux and
enoxaparin as add-on therapy to aspirin and clopidogrel, the drugs
were equally effective for the primary composite endpoint of preventing
death, myocardial infarction, and refractory ischemia at 9 days
(incidence of 5.9 and 5.8 percent, respectively). Participants had
at least one of the three components of the primary endpoint.
Fondaparinux is the first in a new class
of anti-thrombotics that selectively inhibit Factor Xa, a central
protein in the coagulation process. In the treatment of thrombosis,
Factor Xa plays a central role in the generation of thrombin. Fondaparinux
has a proven safety profile with no reported cases of heparin-induced
thrombocytopenia, a common and potentially fatal side effect of
heparin.
In terms of side effects observed in the
study, fondaparinux was associated with a 47-percent reduction in
major bleeding compared with enoxaparin (2.1 and 4.0 percent incidence,
respectively). Mortality rates at one month were 17-percent lower
in the fondaparinux group (2.9 versus 3.5 percent). This difference
in mortality rates was maintained at six months post therapy (5.8
percent for fondaparinux and 6.6 percent for enoxaparin), representing
an 11-percent reduction in mortality.
"The OASIS 5 findings demonstrate that
fondaparinux is likely an effective anti-thrombotic drug in many
patients with acute coronary syndrome already receiving aspirin
and clopidogrel," said Dr. Salim Yusuf, principal investigator
of the study, and professor of medicine, McMaster University and
Hamilton Heath Sciences, Ontario, Canada.
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