Oral anticoagulation for secondary stroke prevention
32 slide(s) – 00:24:55– English –2010-09-28
Stroke is one of the leading causes of death and disability in the Western world and efforts should be made to prevent its occurrence. Oral anticoagulation (OAC) is the first-choice secondary prevention strategy in patients with cardioembolic stroke due to atrial fibrillation. OAC with vitamin K agonists (VKA) is associated with a 70% risk reduction in recurrent stroke compared to 15% with aspirin. About 80 strokes per 1,000 patients per-year can be prevented with OAC. The target INR should be between 2 and 3. However, the use of VKA has many limitations including a narrow therapeutic range, necessitating frequent anticoagulation monitoring and dosage adjustment. Recent studies have shown that the INR is outside the therapeutic range during 30%-40% of the time in well-controlled stroke populations receiving OAC with VKA.A possible alternative for VKA appears to be the direct thrombin inhibitors (DTI), a new class of oral anticoagulants. In preliminary studies they showed advantages over VKA with regard to a predictable anticoagulant response not requiring routine anticoagulation monitoring. OAC should not be used for secondary prevention of stroke in patients who have suffered a prior TIA or stroke of non-cardioembolic origin (including individuals with symptomatic intracranial artery stenosis). The evidence supports the use of antiplatelet agents in these patients (aspirin, clopidogrel or a combination of aspirin and extended-release dypyridamole). The safety and efficacy of OAC is currently investigated in specific non-cardioembolic ischemic stroke subgroups including patients with paradoxical embolism due to patent foramen ovale, cervical artery dissections and cerebral venous thrombosis.