Stroke Prevention in Atrial Fibrillation II "SPAF II"


Phase N/A Results

Trial Description

To define the benefits and risks associated with warfarin compared with aspirin in a large number of patients followed for a longer period of time (compared to SPAF I) according to age and inherent risk of thromboembolism.


  • Warfarin (Coumadin┬«)Drug
    Other Names: Coumadin
    Intervention Desc: Anticoagulant (Vitamin K antagonist)

Trial Design

Two parallel, randomized, placebo-controlled clinical trials of 1100 patients at 16 U.S. centers. One trial studied patients >75 years of age, the other <=75.

Patient Involvement

Patients were randomized to receive warfarin or aspirin (325 mg daily).


Type Measure Time Frame Safety Issue
Primary Ischemic stroke and systematic embolism as assessed every 3 months
Secondary Effect of therapies on all strokes with residual functional deficit (ischemic or hemorrhagic) and primary events plus vascular death. Also, reduction of primary events among patients considered to be at high inherent risk for thromboembolism.


National Institute for Neurological Disorders and Stroke, NIH