A drug already being used to lower cholesterol and prevent heart attacks sharply reduced strokes in patients who already had heart disease, a Wake Forest University researcher told the American Heart Association meeting today (Nov. 8) in Atlanta.
Robert P. Byington, Ph.D., professor and head of the Section on Epidemiology, said the drug, pravastatin, reduced stroke by 20 percent, compared to placebo, in patients with heart disease or high cholesterol.
The study "offers a major new way to lower the stroke rate," Byington said.
He said the drug reduced the risk of stroke over a wide range of cholesterol values and among a wide spectrum of patients in pooled data from three similar clinical trials. The effect occurred primarily in the patients who already had coronary heart disease, where the reduction was 22 percent.
The Prospective Pravastatin Pooling Project began in 1992, before any of the three clinical trials were completed. The three trials - WOS (West of Scotland coronary prevention study), CARE (Cholesterol And Recurrent Events) and LIPID (Long-term Intervention with Pravastatin in Ischemic Disease) totaled 19,768 participants from Scotland, the United States, Canada and Australia-New Zealand.
All were randomized clinical trials that compared 40 milligrams per day of pravastatin to an inert placebo. WOS was conducted in patients with very high cholesterol levels, while CARE and LIPID involved coronary heart disease patients. The data was collected as the studies were underway, with patients remaining in the study an average of five years.
Over the course of the three studies, a total of 267 patients on pravastatin had strokes, compared to 331 patients on the placebo, a statistically significant difference. The stroke rate declined from 6.5 per thousand per year in the placebo group to 5.2 per thousand in the pravastatin group. Most of the strokes were non-fatal; the number of fatal strokes was just about the same in both groups.
The drug prevented the type of stroke caused by the blocking of an artery in the brain, a situation similar to the blocking of a coronary artery in the heart (which leads directly to a heart attack.)
He noted that the effect on stroke was somewhat unexpected. "People have been combining the results from lipid [cholesterol] lowering trials for years and even as late as 1992, in one of the last analyses, there was zero difference in strokes between the groups that were on lipid-lowering drugs and the people who were on placebo."
These earlier studies were done with other kinds of drugs that lower cholesterol. When the class of drugs called statins became available in the late 1980s, "we began seeing a much larger reduction in lipid levels, and amazingly, hints of reduction in stroke - and we weren''t expecting to see that at all."
The new study is strong evidence that pravastatin reduces strokes.
About 600,000 people suffer a non-fatal strokes each year in the United States, and these strokes are a leading cause of serious long-term disability and extensive and expensive rehabilitation.
The Prospective Pravastatin Pooling Project was funded by Bristol Myers Squibb, as were WOS, CARE and LIPID.
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