How much warfarin is enough in APS related thrombosis?

Overview

Warfarin is the best available, most effective treatment for the secondary prevention of recurrent thrombosis in antiphospholipid syndrome (APS) patients. However, warfarin is cumbersome for both patients and physicians because of risk for bleeding and the need for frequent monitoring. Much detail regarding optimal management of APS patients still lacks an evidence-based approach. Asymptomatic patients should not receive warfarin. An optimal treatment for patients with livedo, cardiac valve disease, leg ulcers or microangiopathic nephropathy is unknown; it is likely that warfarin is ineffective for these manifestations of the APS. In low risk patients who have not previously failed warfarin, moderate intensity anticoagulation (target international normalized ratio [INR] 2.5) is as effective as, and safer than, high intensity anticoagulation (INR 3.5), at least for patients with venous thrombosis. Current recommendations, based on the opinion rather than on documentation, state that warfarin should be prescribed for the APS patient's life; studies that challenge this conclusion for carefully defined low risk patients whose thromboses occurred with trigger events will be welcome, as will be studies examining alternatives to warfarin, including antiplatelet drugs.