U.S. Food and Drug Administration
FDA Consumer magazine
January-February 2002
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Stroke is the third leading cause of death in the United States and the leading cause of serious, long-term disability. About 600,000 new strokes are reported in the United States annually and about 160,000 Americans die each year from stroke.
A study appearing in the Nov. 15, 2001, issue of The New England Journal of Medicine indicates that aspirin works as well as warfarin in helping to prevent recurrent strokes in most patients.
The study, called Warfarin versus Aspirin Recurrent Stroke Study (WARSS) was a seven-year double-blind, randomized clinical trial involving 2,206 patients at 48 participating centers--the largest trial to date comparing aspirin to warfarin for recurrent stroke prevention. It was sponsored by the National Institute of Neurological Disorders and Stroke (NINDS).
"Treatment is far superior to no treatment and treatment with either aspirin or warfarin is safe under carefully monitored conditions," says J. P. Mohr, M.D., director of the stroke unit at Columbia University's College of Physicians and Surgeons and lead investigator of the trial.
Both drugs slow clotting of the blood, and blood clots are involved in the final stages of the most common type of stroke due to blockage of the vessels that supply oxygen-rich blood to the brain. Aspirin affects the blood platelets, while warfarin inhibits circulating clotting proteins in the blood.
Aspirin has been used for over 100 years, but its beneficial effects to prevent stroke and heart attack only started to be recognized in the 1970s. Whether warfarin was superior to aspirin for stroke prevention was unclear prior to WARSS. Numerous previous studies have proven that use of aspirin reduces recurrent stroke by about 25 percent.
Part of the controversy about aspirin versus warfarin for stroke prevention has been the thinking among physicians. Many say that warfarin may be a better blood thinner than aspirin to prevent almost all forms of stroke, but add that it has greater side effects, increased risk of hemorrhage, and higher costs due to the need for blood tests to monitor the treatment effect.
An earlier NINDS trial cleared up some of the confusion by showing a distinct benefit of warfarin over aspirin in preventing recurrent stroke in patients whose stroke was related to atrial fibrillation (AF)--strokes caused by clots coming from the heart. About 15 percent of stroke patients have this heart rhythm abnormality, a condition in which the two upper chambers of the heart (the atria) do not have a rhythmic, forceful beat and the pulse is irregular.
However, greater insight was needed to determine the best therapy in preventing recurrent stroke in the larger number of patients without clots in the heart--the purpose of the WARSS study.
To make the aspirin and warfarin arms of the study as unbiased as possible, the investigators matched both groups of patients for primary stroke severity, age, gender, education, and race/ethnicity. The two groups were also matched for stroke risk factors, including hypertension, diabetes, cardiac disease, smoking, alcohol consumption, and physical activity.
The investigators used an aspirin dose of 325 milligrams per day and a warfarin dose specifically tailored to each individual patient. They also used a double-blind plan in which neither the treating doctor nor the patient knew which treatment was being received.
The researchers say additional analysis of the WARSS data may point to differences in the ability of aspirin and warfarin to prevent stroke for some patients. However, there was no evidence of significant differences overall between the two drugs.
Older men who see life's glass as being half full rather than half empty may be less likely to develop coronary heart disease, a new study indicates.
Researchers ranked a group of more than 1,000 older men based on a scoring system that characterized them along a continuum from pessimist to optimist. They found that each step up the scale toward optimism decreased the risk of coronary heart disease (CHD). The men ranked as being most optimistic had a risk of heart disease less than half of that of those ranked the most pessimistic, according to a study published in the November-December 2001 issue of Psychosomatic Medicine.
"These ... data are among the first to demonstrate that a more optimistic [perspective], or viewing the glass as half full, lowers the risk of CHD in older men," says lead author Laura D. Kubzansky, Ph.D., of the Harvard School of Public Health.
The study is based on data from 1,306 men whose average age at enrollment was just over 60 and who were followed for an average of 10 years.
Despite the protective effect on the development of CHD, the optimistic men were no less likely to die of any cause than were pessimistic men in the study. This may have been related to the fact that all the men, as veterans, had ready access to health care through the Department of Veterans Affairs, reducing their risk of dying from heart disease, according to the study.
The researchers suggest that the protective effects of optimism may be, in part, due to lower stress, which has been shown to decrease heart disease risk. Also, optimists are more likely to engage in health-promoting activities such as exercising and not smoking. However, the researchers note that their findings pertain specifically only to white men and cannot be generalized to women or non-white men.
The study was supported with funding from the National Heart, Lung, and Blood Institute and the National Institute on Aging.
Cardiovascular disease is the No. 1 killer in most industrialized countries. A new study indicates that combining the use of a statin drug and niacin can reduce the risk of heart attack or hospitalization for chest pain by 70 percent among people likely to suffer heart attacks and/or death from coronary heart disease.
The treatment used in the study combined two well-known ways of improving cardiac health: the use of a statin drug called simvastatin to lower levels of the so-called "bad" cholesterol, LDL, and the use of niacin, also called vitamin B-3, to boost levels of the "good" cholesterol, HDL. Niacin is the best agent known to raise blood levels of HDL, which helps remove cholesterol deposits from the artery walls.
The study, done by researchers at the University of Washington and published in the Nov. 29, 2001, issue of the New England Journal of Medicine, found that the combined treatment, in people with low levels of HDL and average levels of LDL, could even reverse plaque buildup in the arteries.
"This study shows that improving cholesterol levels in people with heart disease--especially lowering LDL cholesterol substantially, together with raising HDL cholesterol--greatly reduces the risk for a heart attack and heart disease complications and can actually reverse the buildup of cholesterol in the arteries of the heart," said Claude Lenfant, M.D., director of the National Heart, Lung, and Blood Institute, which funded the study.
Researchers also looked at the effect of a mixture of antioxidant vitamins on cardiovascular outcomes. The antioxidants involved in this study include vitamins C and E, beta-carotene and selenium.
The study found that the mixture of antioxidant vitamins actually blunted the expected rise in the "good" HDL cholesterol usually seen with the simvastatin and niacin combination. Scientists are not sure why this is so, since there has been laboratory evidence that suggests antioxidants should be helpful.
At the start of the study and again after three years of treatment, doctors performed angiograms on the arteries of the 160 people in the study. The angiograms, using computerized measurements, showed that in most of the people who received the combination treatment, plaque buildup had actually decreased.
"This is the first demonstration of a striking clinical benefit from this form of combination drug therapy used in patients with a common type of coronary disease," says B. Greg Brown, M.D., lead author of the study and a cardiologist at the university's medical school.
Giving statins to people with cardiovascular disease is now common, and has been proven to reduce cardiovascular risk by 25 percent to 35 percent over five years of treatment. The study involved use of niacin at moderately high and carefully supervised levels. Brown said that patients should only take niacin under a doctor's supervision. Rarely, the unsupervised use of niacin can cause severe liver problems, including liver failure.
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