(RxWiki News) High blood pressure is the most important risk factor for stroke that you can change, according to the American Heart Association. A lower pressure may also ward off having additional strokes.
When a person has an ischemic stroke, a clot in a blood vessel stops blood from reaching the brain. Survivors of small artery strokes who lower their blood pressure may be less likely to have a hemorrhagic stroke (bleeding in the brain), according to a new study.
"Have your blood pressure checked regularly."
Oscar Benavente, MD, professor and research director of stroke and cerebrovascular health at the University of British Columbia in Vancouver, Canada, collaborated with other scientists who observed 3,020 patients who had experienced small subcortical strokes. These strokes are in the small vessels deep in the brain.
Patients were age 63 on average, 63 percent were men, 75 percent had a history of high blood pressure, 37 percent had a history of diabetes and 20 percent were current tobacco users.
All patients took blood pressure lowering medication to reach a lower healthy blood pressure. Investigators, however, divided patients into two groups: one included those who were to reach a lower targeted systolic pressure of 130 mm Hg and the other was to reach a higher targeted systolic pressure between 130 and 149 mm Hg. Patients assigned to the lower target took more medications.
Systolic pressure is the measurement of maximum force of the blood in the arteries as opposed to diastolic, which is the pressure measurement when the heart is relaxed. The American Heart Association defines normal blood pressure as less than 120 mm Hg for systolic and less than 80 mm Hg for diastolic.
Pre-hypertension is systolic pressure between 120 mm Hg and 139 mm Hg. People with pre-hypertension are likely to develop high blood pressure unless steps are taken to control it. Hypertension or high blood pressure is systolic pressure above 140 mm Hg.
Those assigned to reach a lower blood pressure had an average systolic blood pressure of 126.8 mm Hg while the other group averaged 137.8 mm Hg.
Bleeding in the brain, also known as intracerebral hemorrhage, was reduced by 63 percent in those who achieved the lower blood pressure levels.
While the likelihood of the bleeding type of stroke was lowered, there was no significant difference in the likelihood of clot-caused stroke with lower blood pressure. Also, although the lower blood pressure target was safe, it did lead to more episodes of fainting.
“We know keeping blood pressure low protects against a first and a recurrent stroke,” said Dr. Benavente. “What the study tells us is that a systolic reading of 135 mm Hg may not be enough, but that getting the blood pressure down to below 130 mm Hg may offer our stroke patients greater clinical benefits. I would tell my patients who had this type of stroke to get their blood pressure below 130.”
The study was presented in February at the American Stroke Association’s International Stroke Conference 2013. The research was funded by National Institute of Neurological Disorders and Stroke. Research presented at academic conferences should be considered preliminary until published in a peer reviewed journal.