Antiplatelet 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. 

The AHA/ASA guidelines recommend that antiplatelet therapy as the cornerstone of antithrombotic therapy for the secondary prevention of ischemic stroke and should be used in noncardioembolic strokes. Aspirin, dopidogrel, and extended-release dipyridamole plus aspirin are all considered first-line antiplatelet agents (see Table 13-1). The combination of aspirin and clopido-grel can only be recommended in patients with ischemic stroke and a recent history of myocardial infarction or coronary stent placement and then only with ultra-low-dose aspirin to minimize bleeding risk. 

Antiplatelet therapy is the cornerstone of secondary prevention of ischemic stroke. 

All patients who have had an acute ischemic stroke or TEA should receive long-term antithrombotic therapy for secondary prevention. In patients with noncardioembolic stroke, this will be some form of antiplatelet therapy. In a recent meta-analysis, the overall benefit of antiplatelet therapy in patients with atherothrombotic disorders was estimated to be 22%. Aspirin is the best-studied of the available agents and, until recently, was considered the sole first-line agent. However, published literature has supported the use of clopidogrel and the aspirin plus extended-release dipyridamole combination product (ERDP + ASA) as additional first-line agents in secondary stroke prevention. 

Use of warfarin in the secondary prevention of noncardioem-bolic stroke was addressed in the Warfarin Aspirin Recurrent Stroke Study. In 2206 patients with recent stroke, warfarin (INR = 1.4—2.8) was not superior to aspirin 325 mg/day in the prevention of recurrent events. This led many clinicians to abandon the practice of using warfarin as an alternative agent in patients who suffered recurrent events while on antiplatelet therapy in favor of combination or alternate antiplatelet therapy. 

Antiplatelet (Aspirin) Therapy in Secondary Prevention of Myocardial Infarction (Ml) ... 

Tomaselh GF (2015) Introduction to a compendium on sudden cardiac death epidemiology, mechanisms, and management. Circ Res 116 1883-1886 Udell JA, Bonaca MP, Collet JP et al (2016) Long-term dual antiplatelet therapy for secondary prevention of cardiovascular events in the subgroup of patients with previous myocardial infarction a collaborative meta-analysis of randomized trials. Eur Heart J 37 390-399 Unudurthi SD, Hund TJ (2016) Late sodium current dysregulation as a causal factor in arrhythmia. Expert Rev Cardiovasc Ther 14 545-547... 

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