Currents: Spring 2001, Volume 2, Number 2
Comment by Harold P. Adams, Jr., M.D., Professor, Department of Neurology; Director, Division of Cerebrovascular Diseases, and Patricia H. Davis, M.D., Associate Professor, Department of Neurology
Stroke Council of the American Heart Association/American Stroke Association
(www.americanheart.org) and
National Stroke Association (www.stroke.org)
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A number of advances in the primary and secondary prevention of stroke have occurred during the last few years. In an effort to share information about these developments, a series of guidelines and statements have been authored by panels of the Stroke Council of the American Heart Association/American Stroke Association and the National Stroke Association. These communications cover a spectrum of recommendations for evaluation and treatment of patients who have a high risk for ischemic cerebrovascular disease. The distinction between primary prevention (treatment of patients who have not had any neurological symptoms) and secondary prevention (treatment of patients who have had a prior transient ischemic attack or ischemic stroke) is somewhat arbitrary, since the management options are similar for the two groups of patients. Nonetheless, management of patients with prior neurological symptoms does involve a greater sense of urgency because of the higher risk of a serious stroke. The foundation for stroke prevention includes measures to control factors that promote the development of atherosclerosis. Foremost among these are treating arterial hypertension and hypercholesterolemia and encouraging changes in lifestyles, including increased physical activity, weight reduction, smoking cessation, and limited alcohol consumption. The strength of the supporting data is considerable. Addressing these issues is also effective in preventing serious ischemic events besides stroke. The guidelines' recommendations help clinicians in their decisions about strategies of care for the individual patient. In the past, elevated cholesterol levels were not considered a critical risk factor for ischemic stroke. However, recent clinical and epidemiological data show the importance of the elevated cholesterol levels in accelerating cerebrovascular atherosclerosis. As a result, administering statins is becoming a significant component of primary prevention of stroke in patients with coronary artery disease. In addition, administration of ramipril (an ACE inhibitor) has been shown to reduce vascular events, including stroke, among high-risk patients, especially those with diabetes mellitus. Several clinical trials demonstrate a substantial benefit from oral anticoagulation for both the primary and secondary prevention of ischemic stroke among patients with atrial fibrillation. Unfortunately, many patients with atrial fibrillation, including those who have had neurological symptoms, are not being treated with anticoagulants. The recent guidelines strongly endorse this therapy, and practicing physicians need to heed the recommendations. If a patient is judged to be at high risk for hemorrhagic complications from oral anticoagulants, aspirin can be prescribed. Both anticoagulants and antiplatelet aggregating agents are effective in lowering the risk of stroke among patients with recent neurological symptoms. Anticoagulants usually are prescribed to patients with cardioembolic stroke, but the role of these medications in preventing ischemic stroke among patients with arterial diseases is less clear. Several antiplatelet aggregating agents (aspirin, aspirin/dipyridamole, ticlopidine, or clopidogrel) are available, and selection of the medication is made on a case-by-case basis. The current guidelines provide recommendations that can be used by primary care physicians. They also provide advice about the indications for carotid endarterectomy and other vascular reconstructive procedures to prevent stroke. The role of carotid endarterectomy in primary prevention is more controversial than its use in preventing stroke among patients with prior ischemic symptoms. This in large part is due to the observation that the risk of stroke is considerably lower among patients who have an asymptomatic stenosis of the internal carotid artery. In these cases, it is important to know the complication rate of the surgeon performing the operation. The use of carotid angioplasty and stenting as an alternative to carotid endarterectomy is being tested in a prospective, multicenter, randomized clinical trial. In summary, prevention remains the best approach to reducing the burden of ischemic stroke. These guidelines will help the primary care physician target those individuals who are at the highest risk for stroke. Other relevant references: Carotid angioplasty and stenting. Bettmann et al, Stroke 1998;29:336-338. Preventing ischemic stroke in patients with prior stroke and transient ischemic attack. Wolf et al, Stroke, 1999;30:1991-1994 Primary prevention of ischemic stroke. Goldstein et al, Stroke 2001;32:280-299 Prevention of a first stroke. Gorelick et al, JAMA 1999;281:1112-1120 |