By Dennis Thompson
WEDNESDAY, May 23, 2018 (HealthDay News) -- One out of every three U.S. adults has high blood pressure that should be treated with medication, under guidelines recently adopted by the two leading heart health associations.
The American College of Cardiology and American Heart Association redefined high blood pressure at 130/80 in November, down from the previous level of 140/90, based on new evidence supporting a lower threshold.
Under the new guidelines, nearly 46 percent of U.S. adults now would be considered to have high blood pressure, a new study reported.
Further, 36 percent would be recommended for blood pressure medication, the study authors said.
That means the number of American adults diagnosed with high blood pressure would grow to 105 million from 74 million, and those who should be taking medication to 83 million from 72 million.
Full implementation of the new guidelines would mean 156,000 fewer deaths each year, and 340,000 fewer heart attacks, strokes and other heart-related ailments, the researchers concluded.
"Our study shows the benefit of risk reduction overweighs the potential risk of adverse events in the U.S. population," said study author Dr. Jiang He.
"We highly recommend practitioners to try to adhere to the new guidelines," said He, who is chairman of epidemiology with the Tulane University School of Public Health and Tropical Medicine in New Orleans.
Some debate has occurred since adoption of the new guidelines regarding risks associated with blood pressure medication, said Dr. Clyde Yancy, chief of cardiology with the Northwestern University Feinberg School of Medicine in Chicago.
"Whenever there is a change in the approach to a common problem that requires an entire rethink of what has been a standard of care, there's going to be some argument, some pushback, some hesitancy," Yancy said.
But the new study reveals that the potential benefits of the new guidelines far outweigh the risks, he added.
The researchers reported that doctors need to treat 70 people to prevent one case of heart attack or stroke, and 129 people to prevent one death.
By comparison, treatment numbers that would increase side effects associated with blood pressure medication are much higher:
- 468 people would need to be treated to cause one case of kidney injury.
- 603 treated to cause one case of dangerously low blood pressure.
- 1,171 treated to cause one person to pass out from a fall in blood pressure.
- 1,189 treated to cause one case of abnormal electrolyte levels in the blood.
"The number needed to harm is hundreds or thousands, but the number needed to benefit is not only less than 100, but it's exactly in keeping with the threshold set for statin therapy for primary prevention," Yancy said.
"We've already decided when the number needed to treat to improve outcomes is less than 100, that qualifies an important public health imperative," Yancy explained
He noted that 9 percent of people now considered to have high blood pressure would not be recommended for medication. Instead, they would try to lower their blood pressure through exercise, diet and other lifestyle changes.
Under the new guidelines, everyone with stage 1 high blood pressure should be evaluated for heart disease. Only those with heart disease or at high risk for developing it during the next decade would be prescribed drugs.
"The majority of people who are newly diagnosed ought to be able to be managed with non-drug regimens," Yancy said. "We should not dismiss those approaches. There is substantial benefit to be had by appropriately deploying these lifestyle and dietary changes."
Both Yancy and He said doctors should embrace the new guidelines, since many more lives would be saved.
"If your reason for reluctance is about risk, we've done the risk assessment," Yancy said. "The data reflect one big step toward better implementation and better outcomes."
The new study was published online May 23 in JAMA Cardiology.