Anticoagulation therapy secondary prevention

Warfarin has not been adequately studied in non-cardioembolic stroke, but it is often recommended in patients after antiplatelet agents fail. One small retrospective study suggests that warfarin is better than aspirin.30 More recent clinical trials have not found oral anticoagulation in those patients without atrial fibrillation or carotid stenosis to be better than antiplatelet therapy. In the majority of patients without atrial fibrillation, antiplatelet therapy is recommended over warfarin. In patients with atrial fibrillation, long-term anticoagulation with warfarin is recommended and is effective in both primary and secondary prevention of stroke.12 The goal International Normalized Ratio (INR) for this indication is 2 to 3. 

Apart from surgical and interventional therapy of occlusive carotid artery disease, the major approach to preventing vascular disease and subsequent stroke is to pay close attention to the control of modifiable risk factors such as hypertension, smoking, diabetes, and hypercholesterolemia. Coumadin, an anticoagulant, is effective for the primary and secondary prevention of stroke in patients with atrial fibrillation. Aspirin, clopidogrel, and the combination of aspirin and cUpyridamole have been proven to be effective for secondary stroke prevention along with the antihypertensive combination of indap-amide and perindopril. 

Following Ml, all patients, in the absence of contraindications, should receive indefinite therapy with aspirin, a 8-blocker and an angiotensin-converting enzyme (ACE) inhibitor for secondary prevention of death, stroke, and recurrent infarction. Most patients will receive a statin to reduce low-density lipoprotein cholesterol to less than 70 to 100 mg/dL. Anticoagulation with warfarin should be considered for patients at high risk of death, reinfarction, or stroke. 

Data from two large, randomized trials demonstrate that the use of low, fixed-dose warfarin (mean INR 1.4) combined with aspirin or of low-intensity anticoagulation (mean INR 1.8) monotherapy provides no significant clinical benefit compared with aspirin monotherapy but significantly increases the risk of major bleeding. Therefore, warfarin therapy targeted to an INR of less than 2 cannot be recommended for secondary prevention of CHD events following MI. 

Blanchard E, Ansell J. Extended anticoagulation therapy for the primary and secondary prevention of venous thromboembolism. Drugs 2005 65 303-311. 

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