http://www.theheart.org/web_slides/1136777.do Fifth Organization to Assess Strategies in Acute Ischemic Syndromes

1. OASIS-5 (Fifth Organization to Assess
Strategies in Acute Ischemic Syndromes)

2. OASIS-5 (Fifth Organization to Assess Strategies in Acute
Ischemic Syndromes)
S Yusuf (McMaster University, Hamilton, ON)
European Society of Cardiology 2005 Congress
• Background:
Fondaparinux is the first of a new class of antithrombotic drugs: selective
factor-Xa inhibitors
• Population and treatment:
20 078 patients randomized within 24 hours of an ACS to fondaparinux
(2.5 mg subcutaneously once daily) or enoxaparin (1 mg/kg twice daily) for
two to eight days
• Primary outcomes:
Primary efficacy outcome: a composite of death/MI/refractory ischemia at
day 9
Primary safety outcome: rate of major bleeding at day 9

3. OASIS-5: Results (efficacy)
• Fondaparinux is as effective as enoxaparin in the reduction of the primary
efficacy end point: HR 1.01 (95% CI 0.90–1.13)
Efficacy results at day 9
End point Enoxaparin Fondaparinux
(n=10 021), % (n=10 057), %
Death/MI/refractory ischemia 5.8 5.9
Death/MI 4.1 4.1
Death 1.9 1.8
MI 2.7 2.7
Refractory ischemia 1.9 2.05

4. OASIS-5: Results (safety)
• 47% reduction in major bleeds at day 9 with fondaparinux
• Net clinical benefit—combination of efficacy and bleeding results—at day 9 with
fondaparinux (HR 0.82 , 95% CI 0.74–0.90; p<0.00001)
Bleeding results at day 9
End point Enoxaparin Fondaparinux HR (95% CI) p
(n=10 021), % (n=10 057), %
Total bleeds 7.0 3.2 0.44 (0.39–0.51) <0.0001
Major bleeds 4.0 2.1 0.53 (0.45–0.62) <0.0001
TIMI major bleeds 1.3 0.7 0.54 (0.41–0.73) <0.0001
Minor bleeds 3.1 1.1 0.35 (0.28–0.43) <0.0001

5. OASIS-5: Commentary*
"This new drug . . . has a net clinical benefit at no greater financial cost."
- Dr Salim Yusuf
"There is no doubt in my mind that this drug is preferable to enoxaparin. Physicians
will have to think twice or thrice before prescribing enoxaparin after seeing these
reductions in bleeding and mortality with fondaparinux."
- Dr Shamir Mehta (co–
lead investigator)
"This is a great situation that we have previously only dreamed about."
- Dr Robert Califf
*All comments from OASIS-5/Michelangelo: Dramatically reduced bleeding favors fondaparinux over
enoxaparin in ACS (http://www.theheart.org/article/554453.do)

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