Medword.com

Thursday March 25 2:20 PM ET
NEW YORK, Mar 25 (Reuters Health) -- To help prevent some of the 731,000 strokes suffered by Americans each year, the National Stroke Association (NSA) has issued guidelines on the best way for physicians to treat those people at greatest risk.

The guidelines, which are published in the March 24/31 issue of The Journal of the American Medical Association, were based on a review of medical studies. The following is a list of six conditions identified as risk factors for stroke and recommendations for treatment:

-- Hypertension -- the most prevalent and modifiable risk factor for stroke. Results of studies show that a decrease in diastolic blood pressure (the lower number in a blood pressure reading) of 5 to 6 mm Hg reduces the risk for stroke by 42%. Recommendations include lifestyle modifications, such as weight reduction and physical activity, treatment with medication to lower blood pressure, and strategies to improve patients' adherence to medication regimens.

-- Heart attack -- the risk of stroke is increased in the first month after a heart attack. Use of anticoagulants, antiplatelet agents, and cholesterol-lowering agents are recommended. Anticoagulants, such as warfarin, are recommended for patients who have had a heart attack and also have one or more of these conditions: persistent atrial fibrillation (a heart rhythm disorder); decreased function of the left ventricle (the heart's main pumping chamber); or blood clots detected in the left ventricle after the heart attack.

-- Atrial fibrillation -- electrical misfiring in part of the heart resulting in inefficient pumping of blood. Atrial fibrillation affects more than 2 million adults in the US and increases risk of stroke six-fold. About 36% of strokes in patients aged 80 to 89 are attributed to atrial fibrillation. Warfarin is recommended for patients 75 and older; in patients under age 75, warfarin or aspirin is recommended, depending on other risk factors.

-- Diabetes -- may increase risk of stroke through acceleration of atherosclerosis. Studies have not conclusively shown that tight control of blood sugar reduces risk of stroke, but the NSA recommends ``rigorous comprehensive control of blood sugar levels... as we await more information.''

-- High cholesterol -- the NSA supports the use of pravastatin for patients who have had a heart attack and have average cholesterol levels of less than 240 mg/dL, and simvastatin for patients with coronary heart disease and high cholesterol.

-- Asymptomatic carotid artery disease -- narrowing of the carotid artery. This is ``an important risk factor,'' although mass screening is not cost effective. In patients who have a life expectancy of 5 years or more, less than a 3% surgical risk, and a 60% or greater occlusion of the carotid artery, surgery is recommended.

The NSA guidelines also point to four lifestyle factors that contribute to stroke: lack of exercise, high-fat, high-salt diet, alcohol consumption, and cigarette smoking. The organization suggests regular exercise, such as walking 30 minutes daily; a good diet, low in salt, high in folate, vitamin B6 and B12; moderate consumption of alcohol, (two drinks a day or less); and reducing or quitting cigarette smoking.

The American Heart Association applauded the guidelines in an accompanying commentary.

``The best way to combat stroke is not to have one,'' Dr. Edgar Kenton, a neurologist and American Heart Association board member, commented in a statement to the press.

SOURCE: The Journal of the American Medical Association 1999;281:1112-1120.

Copyright: Paul E. Collier, M.D., F.A.C.S.