Warfarin Versus Aspirin Recurrent Stroke Study

Completed

Phase 3 Results

Trial Description

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

Detailed 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.

Conditions

Interventions

  • Aspirin (stroke prevention) Drug
    Intervention Desc: Antiplatelet agent; inhibits thromboxane A2
  • Warfarin (Coumadin┬«)Drug
    Other Names: Coumadin; Acenocoumarol
    Intervention Desc: Anticoagulant (Vitamin K antagonist)
  • Active Aspirin Drug
    Intervention Desc: 325mg tablet daily
    ARM 1: Kind: Experimental
    Label: Active Aspirin and Warfarin Placebo
    Description: One 325 mg tablet daily of aspirin and one 2 mg scored tablet daily of Warfarin placebo.
  • Active Warfarin Drug
    Intervention Desc: 2mg scored tablet daily
    ARM 1: Kind: Experimental
    Label: Active Warfarin and Aspirin Placebo
    Description: One 2 mg scored tablet daily of Warfarin and one 325 mg tablet daily of aspirin placebo.
  • Aspirin placebo Drug
    Intervention Desc: 325mg aspirin placebo pill
    ARM 1: Kind: Experimental
    Label: Active Warfarin and Aspirin Placebo
    Description: One 2 mg scored tablet daily of Warfarin and one 325 mg tablet daily of aspirin placebo.
  • Warfarin placebo Drug
    Intervention Desc: 2mg scored placebo tablet
    ARM 1: Kind: Experimental
    Label: Active Aspirin and Warfarin Placebo
    Description: One 325 mg tablet daily of aspirin and one 2 mg scored tablet daily of Warfarin placebo.

Trial Design

  • Allocation: Randomized
  • Masking: Double Blind (Subject, Investigator)
  • Purpose: Prevention
  • Endpoint: Safety/Efficacy Study
  • Intervention: Parallel Assignment

Patient Involvement

Patients were randomized to receive either aspirin (325 mg/day) or warfarin (INR 1.4-2.8) for at least two years. Blinded management of INRs using real or computer-generated values.

Outcomes

Type Measure Time Frame Safety Issue
Primary Recurrent ischemic stroke or death from any cause.
Secondary TIAs, MI, adverse experiences (hemorrhage).

Sponsors