By Dennis Thompson
MONDAY, Nov. 9, 2015 (HealthDay News) -- Millions of Americans could avoid heart disease if doctors controlled their high blood pressure more aggressively than previously recommended, a groundbreaking study contends.
The SPRINT trial has revealed that a target systolic blood pressure of 120 reduces by about one-quarter the rate of death, heart attack, heart failure and stroke, compared with the currently recommended target pressures of 140 for people under age 60 and 150 for seniors.
"This is, in my view, the most important blood pressure study of the last 40 years," Dr. Dan Jones, a past president of the American Heart Association, said during a presentation on SPRINT Monday at the association's annual meeting in Orlando, Fla. The final results were also published in the New England Journal of Medicine, to coincide with the meeting presentation.
Systolic pressure is the top of the two blood pressure numbers; it indicates the pressure being placed on blood vessels when the heart beats.
Jones said the SPRINT findings will likely weigh heavily on any future revisions the American Heart Association will make to its blood pressure treatment guidelines.
At least 16.8 million Americans could potentially benefit from the type of aggressive therapy pursued under SPRINT, according to a related report in the Nov. 9 online issue of the Journal of the American College of Cardiology.
That includes 10.8 million adults who directly fall under the guidelines by which people were included in the SPRINT trial -- aged 50 or older, a systolic blood pressure of 130 or higher and at least one additional risk factor for heart disease, said lead author Adam Bress, a research assistant professor of pharmacotherapy at the University of Utah.
"These are the individuals most likely to benefit from a new blood pressure target, because they meet all of the criteria that the SPRINT enrollees met," Bress said. "That's a very large group of people."
But it also includes 3 million people who have systolic blood pressure between 130 and 139 who are already taking medication. "Based on SPRINT, these people may benefit from increasing their dosage or adding more medications," Bress said.
Additionally, there's another 3 million in the 130-139 systolic blood pressure range who are trying to manage their blood pressure solely through lifestyle changes like diet and exercise. "Based on SPRINT, these individuals would highly likely benefit from starting medication," Bress said.
Back in September, the U.S. National Institutes of Health (NIH), which funded the trial, ended it more than a year early so they could share what they called "potentially lifesaving information" with the public.
High blood pressure is a leading risk factor for heart disease, stroke, kidney failure and other health problems, according to the NIH. An estimated one in three people in the United States has high blood pressure.
More than 9,300 participants aged 50 and older were recruited for SPRINT from about 100 medical centers and clinical practices throughout the United States and Puerto Rico.
When SPRINT was first designed, well-established clinical guidelines recommended a systolic blood pressure of less than 140 for healthy adults and 130 for adults with kidney disease or diabetes.
Researchers created the SPRINT clinical trial to see if pushing blood pressure even lower would improve people's health.
The researchers randomly divided the study participants into two groups, one where blood pressure was controlled to the current guidelines and another where systolic blood pressure was kept below 120.
Between 2010 and 2013, the standard group took an average of two different blood pressure medications to meet the recommended goal, while the intensive treatment group received an average of three medications to bring their blood pressure farther down.
The NIH expected to wrap up the study in 2017, but ended it early when officials concluded the results were too important to wait.
The investigators found that people in the intensive treatment group had a 27 percent reduced risk of death, and a 25 percent reduced risk of heart attack, stroke or heart disease, compared with people treated under existing guidelines.
Bress pointed out that the study did not include people with diabetes or who had suffered a stroke, and those people might also benefit from stricter blood pressure control.
The good news comes with one caveat. The participants in SPRINT had a significant increase in some serious side effects, including a two-thirds greater risk of slowed heart rate or abnormally low blood pressure and a one-third greater risk of fainting.
Doctors will have to weigh these potential side effects when treating high blood pressure in individual patients, said Dr. Paul Whelton, chair of the SPRINT steering committee and a clinical professor of epidemiology at Tulane University in New Orleans.
"You're always looking at both sides of the ledger," Whelton said. "There's no treatment that doesn't have an adverse effect. There are some signals, and we shouldn't dismiss them, but when you're looking at a 27 percent reduction in all-cause mortality, I think it's a very powerful result."