Patients with recurrent arterial thrombosis or embolism should be carefully evaluated for: compliance with antithrombotic prophylaxis modifiable risk factors (smoking, blood pressure, lipids) cardiac sources of peripheral embolism (echocardiography) thrombophilias (see Table 4) in patients under 40 years 73 arteritis (e.g. collagen disorders, syphilis) malignant disease.

*	In patients with recurrent arterial thromboembolism despite aspirin or other antiplatelet agents, especially those with cardiac sources of embolism or thrombophilias, prophylactic warfarin (target INR 2.5, range 2.0-3.0) should be considered, balanced against the increased risk of bleeding.

* This is a grade A recommendation for atrial fibrillation or myocardial infarction (see section 3); grade C for patients with peripheral arterial thrombosis (see section 6.1).

In patients with recurrent arterial thrombosis or embolism despite warfarin at target INR of 2.5, range 2.0-3.0, either the addition of aspirin (75 mg/day), high-intensity warfarin (target INR 3.5, range 3.0-4.0), or (if there is further recurrence) high-intensity warfarin plus aspirin (75 mg/day) may be considered. Based on level III evidence19

The increased risk of bleeding with such regimens should be considered.

There is evidence from retrospective studies that in patients with lupus anticoagulants, a target INR of 3.5, range 3.0-4.0, is more effective in prevention of recurrent thrombosis than warfarin at INR range 2.0-3.0.¹³⁴