Nov 13 (Reuters) - Tighter blood pressure guidelines from U.S. heart organizations mean millions more people need to make lifestyle changes, or start taking medication, in order to avoid cardiovascular problems.
Americans with blood pressure of 130/80 or higher should be treated, down from the previous trigger of 140/90, according to new guidelines announced on Monday at the annual meeting of the American Heart Association in Anaheim, California.
At the new cutoff, around 46 percent, or more than 103 million, of American adults are considered to have high blood pressure, compared with an estimated 72 million under the previous guidelines in place since 2003.
High blood pressure accounts for the second-largest number of preventable heart disease and stroke deaths in the United States, second only to smoking.
The guidelines, also endorsed by the American College of Cardiology and 11 other organizations, do not change the definition of normal blood pressure as 120/80 or lower.
Potentially deadly high blood pressure can be brought under control with a wide array of medications, many sold as relatively inexpensive generics. The drug classes include angiotensin receptor blockers, such as Novartis AG's Diovan, calcium channel blockers, like Pfizer Incs's Norvasc, ACE inhibitors, including Pfizer’s Altace, and diuretics, such as Merck & Co Inc’s Hyzaar.
But the drugs have side effects and the new guidelines emphasize lifestyle changes including weight loss, diet and exercise as the first tool for combating hypertension.
"We see lifestyle modification as the cornerstone for treatment," said Dr. Bob Carey, vice-chair of the guidelines committee and professor of medicine at the University of Virginia Health System School of Medicine.
Under the new threshold for initiating treatment, patients assessed to be at higher risk of cardiovascular problems will also be started on medication, he said.
A large, government-sponsored study of hypertension patients aged 50 and older showed in 2015 that death from heart-related causes fell 43 percent and heart failure rates dropped 38 percent when their systolic blood pressure was lowered below 120 versus those taken to a target of under 140.
But patients in the 120 systolic blood pressure group had a higher rate of kidney injury or failure, as well as fainting.
Concerns about those side effects, as well as the fact that the close monitoring seen in a clinical trial is hard to replicate, led the AHA, ACC and other groups to select the 130 systolic blood pressure target.
The new guidelines also emphasize the importance of accurate blood pressure measurements, using an average of different readings at different times.
Adults with blood pressure of 130/80 "already have double the risk of heart attack compared to someone in the normal range," said Dr. Paul Whelton, professor at Tulane University School of Public Health and Tropical Medicine and School of Medicine in New Orleans and lead author of the new guidelines. "It doesn't mean you need medication, but it's a yellow light that you need to be lowering your blood pressure, mainly with non-drug approaches." (Reporting by Deena Beasley; Editing by James Dalgleish)