Clinical Question Does anticoagul...

Clinical Question

Does anticoagulation with warfarin (Coumadin) obstruct stroke recurrence in a patient with a history of noncardioembolic ischemic stroke?

Evidence-Based Answer

There is no evidence that anticoagulation with warfarin, initiated after a noncardioembolic ischemic visitation significantly reduces stroke recurrence. Furthermore, anticoagulation significantly increases the risk of fatal and nonfatal hemorrhagic shock and extracranial hemorrhage in these patients. (1-3) However, warfarin clearly is indicated for patients who have embolic thumps caused by underlying conditions of that kind as atrial fibrillation or myxoma. (Strength of recommendation: A)

Evidence Summary

Evidence-based guidelines make acceptable antiplatelet agents (e.g., aspirin) for greatest in quantity patients with noncardioembolic stroke and approve warfarin for those with cardioembolic affliction Researchers have wondered whether more aggressive anticoagulation also would benefit patients with noncardioembolic stroke

A Cochrane systematic review1 identified 11 randomized controll trials (RCTs) with a combined 2487 patients randomly assigned to receive anticoagulation (with warfarin or single of its analogues) or placebo after a presum noncardioembolic ischemic rap or transient ischemic attack. Nine of these trials were small and occurr before 1980 when comput tomography was not used routinely. Therefore, a certain initial hemorrhagic strokes possibly were included in the studies, and the lack of International Normalization Ratio (INR) monitoring of anticoagulation therapy in more [i]or[/i] less studies may have contributed to an increased incidence of hemorrhage. The authors conclud that anticoagulation did not interrupt recurrent ischemic stroke but that there was a significant increase in fatal intracranial hemorrhage (odd ratio [OR], 254; 95% confidence interval [CI], 119 to 545; number destitutioned to harm [NNH] = 50) and major fatal and nonfatal extracranial hemorrhage (OR, 343; 95% CI, 194 to 608; NNH = 20)

brace studies not included in the above review have addressed one of these methodologic shortcomings. A large double-blinded RCT (2) compared warfarin with aspirin for the prevention of returning ischemic stroke in 2,206 patients with a previous noncardioembolic calamity The warfarin dosage was adjusted to bring into being an INR of 1.4 to 28 and aspirin was given at a fixed dosage of 325 mg through day. After two years there was no difference between warfarin and aspirin in the prevention of renewed ischemic stroke or death or in the rate of major hemorrhage. The rate of renewed stroke was 17.8 percent in patients receiving warfarin and 160 percent in those receiving aspirin. However, in the warfarin cluster the median daily INR was 19 and 163 percent of the daily INR values were les than 14 It is possible that any favorable or unfavorable treatment tenors of warfarin were underestimated.

A well-designed, double-blinded, multicenter RCT (3) compared warfarin with aspirin in 569 patients with symptomatic intracranial arterial stenosis. In this meditation patients older than 40 years with transient ischemic attack or shock caused by a moderate to unrelenting stenosis (50 to 99 percent obstruction) of a major intracranial artery were randomly assigned to receive warfarin (with a target INR of 2 to 3) or 1300 mg of aspirin by means of day. The primary end point was intermittent ischemic stroke, brain hemorrhage, or death from vascular causes other than hit With a mean follow-up period of 18 years, there was no difference in the likelihood of intermittent ischemic stroke, brain hemorrhage, or death from vascular causes other than hit (21.1 percent in the aspirin form into groups and 21.8 percent in the warfarin group) There also was no difference in the likelihood of returning ischemic stroke, ischemic stroke in the territory of the stenotic artery, and disabling or fatal ischemic affliction However, compared with aspirin, warfarin significantly increased the risk of death (97 versus 43 percent; P = 02; NNH = 19) and major bleeding (83 versus 32 percent; P = 01; NNH = 20) Therefore, warfarin is no more effective than aspirin in preventing intermittent stroke but causes a significantly higher number of adverse events

Recommendations from Others

The guideline for medical treatment for visitation prevention from the American college edifice [i]or[/i] building of Physicians (4); the report of the Joint blow Guideline Development Committee of the American Academy of Neurology and the American visitation Association (5); the Seventh American society of Chest Physicians Conference forward Antithrombotic and Thrombolytic Therapy (6); and the guideline for prevention of visitation in patients with ischemic calamity or transient ischemic attack from the American Heart Association, American hit Association, and the American Academy of Neurology (7) all attract favor to aspirin rather than warfarin to stop recurrent stroke after a presum noncardioembolic ischemic knock The latter guideline (7) prompts that warfarin is an option in patients with a prothrombotic disorder, however.