Cutting blood pressure below the currently recommended target can significantly reduce the rate of heart attacks, strokes, heart failure and deaths, federal health officials reported Friday.
The findings come from the largest study ever conducted to examine whether reducing systolic blood pressure — the top number patients get when examined — below the currently recommended goal would be beneficial.
The study was halted early when an analysis indicated the benefits were clear, officials said. "This is landmark study," says Dr. Gary Gibbons, director of the National Heart, Lung and Blood Institute, which sponsored the study. "We think that this study will clearly have an impact on patient care for those with hypertension."
Other experts agreed.
"This is a very big deal," says Dr. Mark Creager, president of the American Heart Association and director of the Heart Vascular Center at the Dartmouth Hitchcock Medical Center in Lebanon, N.H. "I believe that this study will serve as a roadmap towards saving a significant number of lives."
About one-third of U.S. adults have high blood pressure, which is a major risk factor for a variety of health problems, including heart attacks, strokes and heart failure. Currently, most guidelines recommend that high blood pressure patients reduce their systolic blood pressure, which cardiologists consider to be the more important of the two readings from a blood pressure measurement, to a maximum of 140 millimeters of mercury.
But there's been a big debate about whether lower systolic blood pressure might be even better. So the NHLBI sponsored the SPRINT study beginning in 2009. Researchers recruited more than 9,300 adults with high blood pressure and at least one other risk factor for heart disease, such as being a smoker or having high cholesterol. Half of their doctors tried to get their systolic pressure down to 140. The other half shot for 120.
The study was supposed to continue until 2016, but it was stopped recently when a panel monitoring the results found in a preliminary analysis that it had already produced significant results: Reducing systolic blood pressure to 120 or lower reduced heart attacks, strokes and heart failure by almost a third and the risk of death by almost a quarter, Gibbons says.
Details about the findings haven't yet been published in a scientific journal, but will be, the researchers say.
Gibbons, Creager and others said they expected the findings would lead to new guidelines for doctors. But doctors may act sooner.
"If we have a patient in our office tomorrow who fits the criteria of this trial it certainly doesn't seem too early to begin to lower our target to 120," says Dr. Mary Norine Walsh, medical director, heart failure and cardiac transplantation at the St. Vincent Heart Center of Indiana. She is also a vice president of the American College of Cardiology.
Still, it may be difficult for patients to hit the lower target. About half of those who have been diagnosed with high blood pressure fail to reach the current target of 140.
"We have a long way to go in improving public awareness about high blood pressure, making sure it's detected and appropriately treated," Creager says. "But studies such as this really reinforce that we need to take important steps to raise public awareness to make sure that [patients] are having conversations with their health care providers about how it can be effectively managed."
ROBERT SIEGEL, HOST:
The National Institutes of Health has halted a major study about blood pressure because it has produced some startling results. The study found that lowering blood pressure even more than currently recommended could have huge benefits for many people. NPR health correspondent, Rob Stein reports.
ROB STEIN, BYLINE: When someone gets their blood pressure measured, they get two numbers like 110 over 70 or 140 over 90. Both numbers are important, but that first number - systolic blood pressure - has long been considered the really important one. And Gary Gibbons of the National Heart, Lung and Blood Institute says doctors mostly try to keep it below 140 for people in their fifties.
GARY GIBBONS: This is the commonly recommended target of systolic blood pressure of 140.
STEIN: But there's been a big debate about whether getting it even lower would be even better. So researchers began following more than 9,000 people age 50 and older with high blood pressure. Half of their doctors tried to lower that top number to the current target, 140. Half shot for much lower - 120.
GIBBONS: On average, it took two types of medication to control the blood pressure in the standard group to 140, whereas the more intensive group averaged about three medications.
STEIN: And when the researchers took what was supposed to be just an early look at what was happening to make sure nothing was going wrong, the impact of hitting that lower target was surprisingly clear.
GIBBONS: It significantly reduced the rates of heart attacks, heart failure and stroke by 30 percent and lowered the risk of death by 25 percent - pretty substantial. There are not a lot of things in medicine where that occurs.
STEIN: The results were so dramatic, Gibbons says, that officials decided to stop the study early and announce the results this morning.
GIBBONS: This is a major finding, and we think it'll be a landmark study.
STEIN: Other experts agree.
MARK CREAGER: This is a very big deal.
STEIN: Mark Creager is the president of the American Heart Association. He points out that high blood pressure is one of the most common health problems in America. One out of every 3 adults has high blood pressure.
CREAGER: I believe this study will serve as a roadmap towards saving a significant amount of lives.
STEIN: Creager predicted the study would lead his and other major medical groups to revise their guidelines to recommend doctors start shooting for 120 and not only by hiking the dose on the blood pressure drugs they're giving their patients or prescribing more drugs.
CREAGER: In addition to all of that, we have to be mindful of the many other things that are useful in lowering blood pressure, and that includes a healthy diet, particularly one that's low in salt.
STEIN: And some experts predicted many doctors wouldn't wait for official new guidelines to be issued before trying to hit this new target. Mary Norine Walsh is the vice president of the American College of Cardiology.
MARY NORINE WALSH: Seeing a patient, even tomorrow morning, armed with this data - if a patient in front of us is over the age of 50 with cardiovascular risk, using that new target of 120 seems reasonable.
STEIN: But many experts say it won't be easy to hit that new target. Many people who have high blood pressure don't even know it, and about half of those who do haven't been able to get it down to 140 no matter how hard they try. Rob Stein, NPR News. Transcript provided by NPR, Copyright NPR.