Antiphospholipid Antibodies and Stroke Study "APASS"


Phase N/A Results

Trial Description

To evaluate the effect of antiphospholipid antibodies (aPL) positivity on recurrent stroke or thrombotic events.


  • Aspirin (stroke prevention) Drug
    Intervention Desc: Antiplatelet agent; inhibits thromboxane A2
  • Warfarin (Coumadin┬«)Drug
    Other Names: Coumadin
    Intervention Desc: Anticoagulant (Vitamin K antagonist)

Trial Design

Study uses patients enrolled in WARSS, a randomized and double-blind secondary stroke and death prevention trial comparing aspirin and warfarin in two treatment arms. Antiphospholipid antibody status at baseline on all WARSS enrolled subjects. aPL status will also be documented yearly and at the time of a recurrent thrombo-occlusive event for all aPL(+) patients and one matched aPL(-) patient for each aPL(+) patient to ensure blinding of aPL status at each of the WARSS clinical centers.

Patient Involvement

Blood samples were drawn from patients prior to their randomization in the WARSS trial. Samples were analyzed for aPL status by an independent laboratory.


Type Measure Time Frame Safety Issue
Primary Two-year rate of the composite end point of death from any cause, ischemic stroke, transient ischemic attack, myocardial infarction, deep vein thrombosis, pulmonary embolism, and other systemic thrombo-occlusive events.


National Institute for Neurological Disorders and Stroke, NIH