Warfarin Versus Aspirin Recurrent Stroke Study

Columbia University

Status and phase: Completed; Phase 3

Conditions: Stroke

Treatments: Drug: Active Warfarin; Drug: Active Aspirin; Drug: Aspirin placebo; Drug: Warfarin placebo

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT00027066

R01NS028371 (U.S. NIH Grant/Contract)

Details and patient eligibility

About

The goal of this study is to compare aspirin to warfarin for the prevention of recurrent stroke.

Full description

This study compared aspirin to warfarin to determine optimal therapy for the prevention of recurrent stroke. Both drugs slow clotting of the blood. Blood clots are involved in the final stages of the most common type of stroke due to blockage of the vessels that supply oxygen-rich blood to the brain. Aspirin affects the blood platelets, while warfarin inhibits circulating clotting proteins in the blood. Numerous previous studies have proven that use of aspirin reduces recurrent stroke by about 25 percent. Part of the controversy about aspirin versus warfarin for stroke prevention has been the thinking among clinicians that warfarin may be a better blood thinner than aspirin to prevent almost all forms of stroke, but that it has greater side effects, increased risk of hemorrhage, and higher costs due to the need for blood tests to monitor the treatment effect for patients.

To make the aspirin and warfarin arms of the study as unbiased as possible, the investigators matched both groups of patients for primary stroke severity, age, gender, education, and race/ethnicity. The two groups were also matched for stroke risk factors, including hypertension, diabetes, cardiac disease, smoking, alcohol consumption, and physical activity. The investigators used an aspirin dose of 325 mg/day and a warfarin dose specifically tailored to each individual patient.

This study found that aspirin works as well as warfarin in helping to prevent recurrent strokes in most patients.

Sex: All

Ages: 30 to 85 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Inclusion:

• Acceptable candidates for warfarin therapy
• Had an ischemic stroke within the previous 30 days
• Had scores of 3 or more on the Glasgow Outcome Scale

Exclusion:

• Base-line INR above the normal range (more than 1.4)
• History of stroke due to a procedure or that was attributed to high-grade carotid stenosis for which surgery was planned
• History of stroke associated with an inferred cardioembolic source

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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2,206 participants in 2 patient groups

Active Warfarin and Aspirin Placebo

Active Comparator group

Description:

One 2 mg scored tablet daily of Warfarin and one 325 mg tablet daily of aspirin placebo.

Treatment:

Drug: Active Warfarin

Drug: Aspirin placebo

Active Aspirin and Warfarin Placebo

Active Comparator group

Description:

One 325 mg tablet daily of aspirin and one 2 mg scored tablet daily of Warfarin placebo.

Treatment:

Drug: Active Aspirin

Drug: Warfarin placebo