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By Gene Emery
BOSTON, Aug 27 (Reuters) - Two studies released on Wednesday call into question the advantage of using a blood pressure medicine and a well-known blood thinner for preventing the recurrence of a stroke.
The first found that patients who received the blood pressure drug telmisartan were no less likely to have another stroke than those taking a placebo.
In the second study, doctors discovered that aspirin combined with the anti-platelet drug dipyridamole worked no better than the standard anti-clotting treatment clopidogrel for reducing the chance of stroke.
“We found no evidence that either of the two treatments was superior to the other in the prevention of recurrent stroke,” said Ralph Sacco of the University of Miami, who led the study.
“Even though in science you always strive to find a superior treatment, in this case it gives us options for treatment depending on the patient and their response to the different medications.”
Clopidogrel is sold by Bristol-Myers Squibb (BMY.N) under the brand name Plavix while Boehringer Ingelheim GmbH makes dipyridamole under the brand name Persantine.
Both papers, released online by the New England Journal of Medicine, come from the “Profess” study, which included 20,332 patients from 695 medical centers in 35 countries.
Strokes kill about 5 million people worldwide each year and having high blood pressure increases the risk. When a person survives a stroke, there is an 8 percent chance of having another within one year.
That is why telmisartan, sold by various brand names such Boehringer Ingelheim’s Micardis or the Pritor or Kinzal brands by Bayer Schering Pharma BAYG.DE, was given to half the volunteers in the study, led by Salim Yusuf of McMaster University on Ontario, Canada.
After two and a half years of followup, 8.7 percent had another stroke compared to 9.2 percent in the placebo group, an insignificant difference.
The drug, an angiotensin-receptor blocker, also had no effect on the risk of heart attack, other major cardiovascular events or diabetes, the study, paid for by privately held Boehringer Ingelheim, showed.
Among volunteers receiving Plavix as their blood thinner, 8.8 percent had another stroke versus 9 percent for the aspirin-dipyridamole combination. The risk of major bleeding was similar in both groups.
“Furthermore, there was no significant difference between the two treatments in the risk of fatal or disabling strokes,” the researchers wrote.
Drs. David Kent and David Thaler of the Tufts University School of Medicine in Boston agreed the findings were confusing and suggested a Japanese poem called a haiku for understanding it. “For stroke prevention, use an antiplatelet drug, treat hypertension,” they advised.
Editing by Maggie Fox