Warfarin, Aspirin, or Both After Myocardial Infarction
Topic: Antiplatelets in acute coronary syndrome
- Determine benefit of warfarin in secondary prevention after myocardial infarction.
- Randomized, multicenter, clinical trial
- Warfarin (goal INR 2.8 to 4.2), or warfarin with aspirin (75 mg daily, INR goal 2.0-2.5).
- Aspirin (160 mg daily).
- 3,630 patients
- < 75 years of age and hospitalized for acute MI.
- Contraindication to anticoagulation, malignancy, or poor compliance.
- 4 years
- Composite of death from cardiovascular causes, non-fatal reinfarction stroke.
- Each of the above endpoints analyzed independently.
- Mean age 60 years, 76% male.
- Rates of the primary endpoint was reduced in the warfarin alone, and warfarin plus aspirin groups by 19% (P = 0.03, NNT = 100) and 29% (P = 0.001, NNT = 67), respectively, compared to the aspirin alone.
- The difference between both groups receiving warfarin was not statistically significant.
- Event free survival was greatest in the warfarin plus aspirin group (P = 0.003).
- Nearly 4 times as many major bleeding events in the two groups receiving warfarin than in the group receiving aspirin.
- Major bleeding events were not statistically different between groups receiving warfarin, however, incidence of minor bleeding was greater in warfarin plus aspirin group.
TAKE AWAY: Moderate intensity warfarin combined with aspirin and high intensity warfarin alone resulted in a reduced risk of reinfarction and stroke but higher risk of bleeding, compared to aspirin alone.