"High blood pressure is the strongest risk factor for stroke, so you would think patients and their doctors would be vigilant about making sure blood pressure is under control," says researcher Amy Towfighi, MD, assistant professor of neurology at the University of Southern California.
According to the American Heart Association, people with high blood pressure have twice the risk of stroke compared to people with normal blood pressure, and treating high blood pressure with medication and lifestyle changes such as exercise substantially reduces stroke risk.
One study showed that bringing high blood pressure under control would prevent half of strokes, Towfighi tells WebMD. In people with high blood pressure, treatment with medication is recommended to bring levels to less than 140/90.
Towfighi presented the findings at the American Stroke Association’s International Stroke Conference 2012.
More Aggressive Treatment Needed
The study involved almost 500 adult stroke survivors who participated in a national survey from 1999 to 2004. A total of 72% reported they’d been diagnosed with high blood pressure at some point in their lives.
"We wanted to find out if their blood pressure was being treated and had been brought under control since the stroke," Towfighi says. So her team brought them in for blood pressure measurements.
"We were surprised that nearly half had poorly controlled hypertension -- readings over 140/90," she says.
Another 8% who didn't report a history of high blood pressure also had readings over 140/90.
The study also showed that stroke survivors who had diabetes or who were older, female, or Hispanic were more likely to have poorly controlled blood pressure.
Both doctors and stroke survivors need to be more aggressive about treatment, says American Stroke Association spokesman Daniel Lackland, DrPH, professor of epidemiology and neuroscience at the Medical University of South Carolina in Charleston.
There are several different classes of medication that work to lower blood pressure in different ways, and often a patient needs more than one type, he tells WebMD.
So once a patient is started on one class of drug, it shouldn’t be assumed that it will bring blood pressure under control, Lackland says.
Patients may be reluctant to add another drug due to cost or potential side effects, but it could be lifesaving, he says.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.