A large subgroup of WARSS (Warfarin-Aspirin Recurrent Stroke Study) was studied to evaluate whether the presence of a positive antiphospholipid antibody indicated a treatment interaction with warfarin or aspirin for secondary stroke preven- tion. Participants had to be 30 to 85 years of age, to be deemed safe for warfarin therapy, to have experienced an ischemic stroke within 30 days, and to have had a modified Rankin Scale score of 3. Investigators found no differential stroke risk reduction in people with a 1-time positive antiphospholipid antibody with warfarin (RR, 0.99 CI, 0.70 1.28]; treatment-by-antiphospholipid interaction, P=0.91) compared with those without a positive antibody.612 Therefore, aspirin is more preferable than warfarin because of the lower risk of bleeding with aspirin. The prevalence of antiphospholipid syndrome in the stroke popula- tion varies, but younger populations are most com- Approximately 13% of patients with antiphospholipid syndrome have stroke as the initial clinical manifestation of the disease.621 In patients with cryptogenic stroke and a history of thrombosis or rheumatological disease, it would seem reasonable to consider testing for antiphos- In older populations with increasing frequency of vascular risk factors, there is no evidence supporting the systematic testing for antiphospholipid antibodies. 2. Although no trials of antithrombotic intervention have been performed exclusively in stroke patients, the available evidence favors anticoagulation with VKA compared with aspirin to reduce recurrent arterial thromboses. An INR with a target range of 2 to 3 is preferable over an INR with a range >3 because higher-intensity anticoagulation is not superior in preventing thrombotic events and is associated with a higher risk of hemorrhagic com- When anticoagulation has been tested against aspirin, an INR of 2 to 3 is a typi- cal range to be used as a comparison arm, further supporting the use of this therapeutic range as 3. 