(RxWiki News) While bringing down high blood pressure can prevent stroke, it has been less clear whether lowering blood pressure after stroke is beneficial. Researchers recently explored this question.
Stroke is a leading cause of death and disability worldwide, but 80 percent of all strokes can be avoided, according to the National Stroke Association. Controlling blood pressure is often key.
Although blood pressure may be high after a stroke, a recently published report found that taking medication to lower blood pressure immediately after stroke did not make a difference in terms of reducing death risk or preventing a major disability.
"Learn the symptoms of stroke."
Jiang He, MD, this study's lead author and professor of epidemiology and medicine at Tulane University Health Science Center in New Orleans, and fellow researchers studied 4,071 people who had a stroke related to a clot (ischemic) as opposed to one cause by bleeding (hemorrhagic). About 85 percent of all strokes are ischemic.
Participants in this study — the China Antihypertensive Trial in Acute Ischemic Stroke (CATIS) — were from 26 hospitals across China and had high blood pressure upon admittance. Half the patients were randomly assigned to receive blood pressure-lowering medication, while the other half were instructed to stop taking their blood pressure prescriptions within the first 48 hours after the stroke.
For those receiving antihypertensive treatment, the goal was to lower systolic blood pressure by 10 to 25 percent within the first 24 hours after randomization to reach less than 140/90 mm Hg within seven days and then maintain that level during the hospital stay.
Systolic pressure (the top number) is the measurement of maximum force of the blood in the arteries, and diastolic pressure (the lower number) the pressure measurement when the heart is relaxed. The American Heart Association defines high blood pressure as 140/90 and normal blood pressure as 120/80.
At 14 days after the stroke or upon discharge from the hospital, about one third of the patients in each group had either died or developed a major disability.
At three months, that rate dropped to a quarter for each group. As time passed, some patients recuperated from their disability, which lowered the combined percentage of those who died or were disabled.
Lowering blood pressure in the long term is recommended for stroke patients to prevent additional strokes in the future. Unless blood pressure was extremely high, the researchers found no evidence that lowering pressure immediately after stroke was necessary.
“In most cases, treatment is unnecessary because the blood pressure declines naturally over time, and lowering blood pressure may be contraindicated [inadvisable]," said Jose Biller, MD, a member of the study's Data and Safety Monitoring Board and chair of the Department of Neurology of Loyola University Medical Center in Maywood, Illinois, in a press release. "It is important not to overtreat and cause low blood pressure, because the most important objective is to maintain adequate blood flow to the brain."
This study was published in February in the Journal of the American Medical Association (JAMA). The study was supported by Tulane University and Collins C. Diboll Private Foundation; Soochow University, a Project of the Priority Academic Program Development of Jiangsu Higher Education Institutions, China; and the National Natural Science Foundation of China.