Newer Blood Pressure Drug No Better Than Placebo in Preventing Stroke
WEDNESDAY, Aug. 27 -- The blood pressure drug telmisartan does not lower the rate of stroke, cardiovascular events or diabetes better than a placebo in patients who have had a stroke, a new study finds.
Telmisartan is an angiotensin II receptor blocker, which works by blocking the action of chemicals that constrict the blood vessels enabling the blood to flow more smoothly, thus lowering blood pressure.
"Overall, there was no difference in the two groups, people taking telmisartan and those taking placebo," said study co-researcher Dr. Ralph L. Sacco, chairman of neurology at the University of Miami's Miller School of Medicine. "However, we did find a difference in that those who were in the study longer the drug had an effect compared to those who were in the study for a short time."
Sacco thinks that the longer someone takes telmisartan may increase its effectiveness in preventing additional strokes. "These effects have not been seen early after a stroke, they may be more delayed," he said. "The follow-up time in this study was only two a half years, and it may have hurt us."
Blood pressure control is essential in preventing strokes, Sacco said. "But this study in itself doesn't say you have to use angiotensin II receptor blocker early," he said. "Other studies have suggested that these drugs may be better for stroke risk reduction, but in this study, we can't say that."
The report was released early in the Aug. 27 issue of the New England Journal of Medicine.
For the study, Sacco's group randomly assigned 20,332 stroke patients to daily doses of telmisartan or placebo. The researchers looked for incidents of stroke in cardiovascular events such as heart attack and heart failure. They also looked for new cases of diabetes.
Over two-and-a-half years of follow-up, 8.7 percent of patients receiving telmisartan suffered a stroke, compared with 9.2 percent of the patients receiving placebo. In addition, 13.5 percent of patients taking telmisartan had a major cardiovascular event versus 14.4 percent of patients in the placebo group. Diabetes occurred in 1.7 percent of patients taking telmisartan and in 2.1 percent of patients receiving placebo.
In a second study in the same issue of the journal, researchers led by Sacco compared the effectiveness of two drug regimens designed to reduce clotting, Persantine (Dipyridamole) plus aspirin or Plavix (clopidogrel) in preventing new strokes among the same group of patients as in the first study.
"The two drugs were essentially the same in terms of their ability to reduce the risk of recurrent stroke, as well as reducing the risk of heart attack and death after a stroke," Sacco said.
During two-and-a-half years of follow-up, 9 percent of the patients taking Persantine and aspirin suffered a stroke compared with 8.8 percent of those taking Plavix. In both groups, 13.1 percent of the patients had a heart attack or died.
"Both drugs are equally effective; neither drug is superior to the other in terms of reducing a recurrent stroke," Sacco said.
Deciding which drug regimen to use depends on the individual patient, Sacco said. "In some patients, we may use Plavix, particularly in those who have cardiac disease, and in some patients, we may still use this combination of Persantine and aspirin. Choices are helpful, since different people respond differently to different medicines," he said.
For more on stroke, visit the American Stroke Association.
Posted: August 2008