Aspirin therapy secondary prevention

PROFESS is an ongoing large randomized trial examining combination ER-DP plus aspirin therapy compared with clopidogrel (each group also with or without telmisartan, an angiotensin receptor antagonist) for the secondary prevention of early and late recurrent stroke, and other vascular events. 

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 most recent CHEST guidelines continue to recommend aspirin therapy for the secondary prevention of stroke.12 The... 

IgE -mediated urticarial/angioedema reactions and anaphylaxis are associated with aspirin and NSAIDs. Urticaria is the most common form of IgE-mediated reaction. This class is second only to fi-lactams in causing anaphylaxis. The potential for cross-reactivity between agents in IgE-mediated reactions appears small, but caution is advised. Because aspirin therapy is highly beneficial in primary and secondary prevention in... 

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. 

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. 

This study has therefore shown that in patients infected with H. pylori who take low-dose aspirin, eradication of H. pylori is as effective as prophylactic therapy with omeprazole in preventing recurrent upper gastrointestinal bleeding. Therefore, patients taking aspirin for cardiovascular prophylaxis could be tested for H. pylori infection and treated for it if infection is confirmed. In contrast, omeprazole is superior to eradication of H. pylori for the secondary prevention of upper gastrointestinal bleeding in H. py/on-infected users of naproxen and presumably other non-aspirin NSAIDs. 

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. 

In secondary prevention, carotid endarterectomy of an ulcerated and/or stenotic carotid artery is a very effective way to reduce stroke incidence and recurrence in appropriate patients and in centers where the operative morbidity and mortality are low. In fact, in ischemic stroke patients with 70% to 99% stenosis of an ipsilateral internal carotid artery, recurrent stroke risk can be reduced by up to 48% compared with medical therapy alone when combined with aspirin 325 mg daily. In patients in whom the risk of endarterectomy is thought to be excessive, carotid stenting may be effective in reducing recurrent stroke risk but is less invasive. Carotid stenting is still considered investigational, however, and issues remain regarding the optimal methods and patients for this procedure. 

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) ... 

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