The American Heart Association and the American Stroke Association have together issued new guidelines on how to prevent strokes. The new guidelines constitute a thorough reevaluation of the scientific literature on stroke prevention, and contain many differences from the previous set of guidelines, which were published in 2006.
The new guidelines were released online Dec. 2 in Stroke (2010:41 [doi:10.1161/STR.0b013e3181fcb238]).
Among the key recommendations:
• Healthy lifestyle choices, such as not smoking, eating a low-fat diet high in fruits and vegetables, drinking in moderation, exercising regularly, and maintaining normal body weight are additive and together can lower the risk of a first stroke by up to 80%.
• Emergency physicians should attempt to identify patients at high risk of stroke, and they should consider making referrals, conducting screenings, or beginning preventive therapy.
• Genetic screening for stroke risk is not recommended for the general population, but it may be appropriate in some circumstances, depending on family history and other factors.
• The usefulness of carotid artery stenting or carotid endarterectomy for patients with asymptomatic carotid artery stenosis remains uncertain. The advantages of revascularization over medical therapy alone are not well established.
• The general population should not be screened for carotid artery stenosis.
• Low-dose aspirin does not prevent a first stroke in low-risk patients or those with diabetes or asymptomatic peripheral artery disease. Aspirin may be appropriate for patients whose risk of stroke is high enough to outweigh the risk of bleeding with aspirin.
While the recommendations discuss the use of warfarin and antithrombin prophylaxis in atrial fibrillation, there’s no specific recommendation for the use of the oral direct thrombin* inhibitor dabigatran, which received Food and Drug Administration approval on Oct. 19, after the guidelines had been finalized, raising the question of whether the new guidelines are already out of date.
"Everything we do is out of date as soon as it’s done," said Dr. Larry B. Goldstein, who chaired the statement writing committee, in an interview. "Our guidelines aren’t based on whether a drug has been approved or not. They’re based on the science and on the evidence. ... It takes some time to produce these things, but if there’s a new study or studies that become available after a guideline has been published that affects our recommendations, then we publish an intermediate practice advisory."
While he regards dabigatran as very promising, Dr. Goldstein, director of the Duke Stroke Center in Durham, N.C., noted that many questions still remain. For example, it is unknown how often patients on dabigatran should have their liver function tested. If a patient has a bleeding complication while on the drug, there’s no way currently to reverse that. There are suggestions that dabigatran might increase the risk of myocardial infarction and may interact with other drugs, such as verapamil.
"The bottom line is that having this as an option is a very good thing," Dr. Goldstein said. "We’ve had a single drug that’s been proved to be efficacious for decades, but it carries its own baggage. We’re just going to have to see how this fits into clinical practice."
Dr. Goldstein acknowledged relationships with Bayer Corp., Pfizer Inc., and Abbott Labs, and other members of the writing committee had a variety of disclosures that are detailed in the publication.
* CORRECTION, 12/3/2010: The original version of this article misstated the action of dabigatran. It is an oral direct thrombin inhibitor. This version has been updated.