Controlling Hypertension Cuts Stroke Risk
Works even for patients with normal blood pressure
THURSDAY, Sept. 27, 2001 (HealthDayNews) -- Drug treatment to lower blood pressure can reduce the risk of strokes for high-risk patients even if their blood pressure is not abnormally elevated, an international study finds.
Combination drug therapy with two standard blood pressure medications, an ACE inhibitor and a diuretic, reduced the incidence of stroke by almost 30 percent for patients who already had suffered strokes or transient ischemic attacks (TIAs),which are temporary interruptions of blood flow to the brain that often precede a stroke, says a report in the Sept. 29 issue of The Lancet.
The study included more than 6,000 patients at 172 medical centers in Asia, Australasia and Europe. All had experienced strokes or TIAs. Some had hypertension -- high blood pressure -- which the study defined as a reading of 160 over 95; some had blood pressure lower than those levels. Half of them were given a placebo, an inactive substance. The other half were given an ACE inhibitor, sometimes accompanied by a diuretic.
In a four-year follow-up, the incidence of stroke in patients getting the two-drug regimen was 28 percent lower than those getting the placebo, the researchers report. The single-drug treatment did reduce blood pressure but did not reduce the risk of stroke.
"The results should have implications for the care of a large number of patients who survive stroke or a transient ischemic attack," the researchers write. "The responsible physician should consider starting treatment at the time of discharge from hospital or at a post-discharge follow-up visit... Although treatment may commence with a single agent, as it did in the run-in phase of this study, the objective should be to move patients onto combination therapy as soon as possible."
That finding is basically sound, says Dr. Jan A. Staessen, professor of medicine at the University of Leuven in Belgium and author of an accompanying editorial, "in the sense that, to some extent, normotensive patients have to be treated."
But the definition of high blood pressure has changed in the years since the study began, Staessen adds. The researchers defined normotensive -- normal blood pressure -- as anything below 160 over 95. Today, anything over 140 is defined as hypertension, he notes.
And other studies have found that single-drug treatment, with a diuretic alone, can reduce the risk of strokes in such high-risk patients, Staessen says. "My advice to clinicians is to use diuretics to treat patients who have already had a stroke," he adds.
But care must be taken in selecting patients for treatment with diuretics, says Dr. Edgar J. Kenton, chairman of the advisory committee of the American Stroke Association.
Diuretics lower blood pressure by taking fluid out of the body, Kenton says, and "in some patients you have to be cautious about using diuretics because of the risk of dehydration." The age and general physical condition of a patient have to considered, he says, as does the weather. Hot summer days may call for use of other drugs, such as ACE inhibitors or beta blockers, which lower blood pressure by different mechanisms.
The field is still evolving, Kenton adds. "Now we are becoming even more aggressive in treating these patients," he says. "Further studies are still needed."
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"This study provides more ammunition to support the treatment of these patients," Kenton says. "If you treat them for high blood pressure, you get a reduction in the recurrence rate."
Learn more about brain attacks from the National Stroke Association.