June 6 (UPI) -- Rigid adherence to the latest blood pressure guidelines could result in one-third fewer deaths among stroke survivors, according to a study by the American Heart Association and the American Stroke Association.
Researchers used data between 2003 and 2014 from the National Health and Nutrition Examination Surveys to estimate the effect of new guidelines on stroke survivors nationwide. The results were published Wednesday in the Journal of the American Heart Association.
"The potential to reduce mortality and recurrent stroke is immense, because more than half of all strokes are attributable to uncontrolled high blood pressure," lead author Dr. Alain Lekoubou, a clinical instructor in neurology at the Medical University of South Carolina, said in a AHA/ASA press release.
In guidelines released last November, the threshold for high blood pressure -- called stage 1 hypertension -- was changed to at or above 130 mmHg for the top number or 80 mmHg for the bottom number. The previous threshold for high blood pressure was at or above 140/90 mmHg.
With the change, it means 46 percent of U.S. adults are identified as having high blood pressure, compared with 32 percent under the previous definition.
Although more people will be diagnosed with hypertension under the new guideline, only a small increase in the percentage of people will require medication, the AHA said.
Blood pressure-lowering medications are recommended for all stroke survivors with blood pressures of 130/80 mmHg or higher, and additional drugs to reduce blood pressure below that threshold.
The survey, conducted between 2003 and 2014, included 6,250,751 participants at least 21 years old after a stroke. Participates provided blood pressure measurements and were asked about their stroke history and blood pressure treatment.
"The new guideline offers physicians and policymakers a unique opportunity to reinforce the already decreasing stroke-related mortality trends of the last few decades," Lekoubou said. "It is our responsibility to ensure that stroke survivors identified with hypertension are treated more aggressively and to ensure that those on treatment remain on treatment."
Researchers determined there is a 32.7 percent reduction in deaths -- comparing the rates in stroke survivors above and below the 130/80 mmHg target blood pressure: 8.3 percent vs. 5.6 percent.
Also, the proportion of stroke survivors diagnosed with hypertension and recommended for pressure-lowering medication would rise 66.7 percentage points from 29.9 percent to 49.8 percent.
And the percentage of stroke survivors already taking pressure-lowering drugs who will be prescribed additional medication would rise 53.9 percent from 36.3 percent to 56 percent.
The researchers noted it is difficult to treat blood pressure in stroke survivors.
"Stroke survivors can face many hurdles in adhering to treatment, including major neurological impairments and depression, which can reduce the motivation to take medication," Lekoubou said. "Caring for stroke survivors may be complicated because it is primarily a disease of the elderly, who are often taking several medications to treat their medical conditions."