Stroke Guidelines Address Broader Issues

April 1, 2006
Laura Newman, MA

The most comprehensive evidence-based recommendations for preventing a second stroke have been released by the American Heart Association and the American Stroke Association's Stroke Council.1 In contrast with previous clinical practice guidelines, the new guidelines tie transient ischemic attack (TIA) with stroke, said Ralph Sacco, MD, chair of the American Stroke Association's Secondary Stroke Prevention Guidelines Committee.

The most comprehensive evidence-based recommendations for preventing a second stroke have been released by the American Heart Association and the American Stroke Association's Stroke Council.1 In contrast with previous clinical practice guidelines, the new guidelines tie transient ischemic attack (TIA) with stroke, said Ralph Sacco, MD, chair of the American Stroke Association's Secondary Stroke Prevention Guidelines Committee.According to the committee, the time to begin secondary stroke prevention is during the 24-hour hospital stay, when it is crucial to ensure that patients are receiving antithrombotic medications, are educated about risk factor control, and understand that they have an increased risk for a second stroke.Results from the Management of Atherothrombosis with Clopidogrel in High-Risk Patients with Recent Transient Ischemic Attack or Ischemic Stroke (MATCH) trial were the basis for the recommendations on these drugs.2 In the trial, patients with a previous stroke or TIA and additional risk factors were randomly assigned to receive 75 mg/d of clopidogrel or combination therapy with 75 mg/d of clopidogrel plus 75 mg/d of aspirin. The primary end point was a composite of ischemic stroke, myocardial infarction, vascular death, or rehospitalization secondary to ischemic events. Because there was an increased risk of hemorrhage in patients receiving combination therapy, it is not recommended.In assessing the optimum treatment, the committee addressed 2 scenarios: when clinical findings reveal a condition that would require anticoagulation with warfarin; and when no such condition is found and antiplatelet treatment would be the treatment of choice in nonpregnant women. The guidelines, based on Class IIb, Level C Evidence, address a variety of circumstances, including surgical recommendations and prevention of stroke for pregnant women.NEW SURGICAL RECOMMENDATIONS For patients who are highly symptomatic and are candidates for carotid endarterectomy, the procedure should be done early-within the first 2 weeks-rather than later, Sacco explained. In addition, angioplasty and stenting are now considered on a par with, rather than inferior to, carotid endarterectomy.HIGH-RISK PREGNANCIES The committee defined women at high risk as those who had a TIA or ischemic stroke or have high-risk thromboembolic conditions, including known coagulopathy or mechanical heart valves. Throughout pregnancy, unfractionated heparin, given subcutaneously every 12 hours with activated partial thromboplastin time monitoring, may be used. Adjusted-dose low molecular weight heparin with factor Xa can be given as an alternative. Another option would be using unfractionated or low molecular weight heparin until week 13, followed by warfarin until the middle of the third trimester, when unfractionated heparin or low molecular weight heparin can be used.LOW-RISK PREGNANCIES A reasonable option for women at low risk is using either unfractionated or low molecular weight heparin during the first trimester, followed by low-dose aspirin for the remainder of the pregnancy.The committee urged postmenopausal women not to use hormone replacement therapy (HRT). Within the past few years, the best level of evidence-randomized trials-have examined the benefits and harms of postmenopausal hormonal therapy. Two trials not only showed no reduction in stroke recurrence or death but found harm.3,4 The second trial, the Women's Health Initiative, was halted because of an increased risk in vascular events. A separate parallel trial that focused on the risk of stroke for women on HRT after a hysterectomy also found a similar high risk.5REFERENCES1. Sacco RL, Adams R, Albers G, et al. Guidelines for the prevention of stroke in patients with ischemic stroke or transient ischemic attack: a statement for healthcare professionals from the American Heart Association/American Stroke Association Council on Stroke. Stroke. 2006;37:577-617.2. Diener HC, Bogousslavsky J, Brass LM, et al. Aspirin and clopidogrel compared with clopidogrel alone after recent ischaemic stroke or transient ischaemic attack in high-risk patients (MATCH): randomised, double-blind, placebo-controlled trial. Lancet. 2004;364:331-337.3. Viscoli CM, Brass LM, Kernan WN, et al. A clinical trial of estrogen-replacement therapy after ischemic stroke. N Engl J Med. 2001;345:1243-1249.4. Rossouw JE, Anderson GL, Prentice RL, et al. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results from the Women's Health Initiative randomized controlled trial. JAMA. 2002;288:321-333.5. Hulley S, Grady D, Bush T, et al. Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. Heart and Estrogen/progestin Replacement Study (HERS) Research Group. JAMA. 1998;280:605-613.LAURA NEWMAN, MA, is a freelance science writer in New York.