BY AMERICAN HEART ASSOCIATION NEWS
Editor’s note: This is one in a 10-part series of the top medical research advances as determined by American Heart Association volunteer and staff leaders.
It was 2011 when David Baldwin got a diagnosis familiar to millions of Americans: He had high blood pressure. He did as his doctor advised – lost some weight, cut back on salt and took medication. Eight months later, it had dropped a little.
“That’s when I saw the flier on the elevator at work,” said Baldwin, a research coordinator at the University of Alabama at Birmingham who was 62 at the time.
That was his ticket into a study that, four years later, is now likely to launch a wave of newly aggressive treatment of high blood pressure across the U.S. Results showed 43 percent fewer cardiovascular disease-related deaths in patients who dropped their systolic pressure to near 120 – instead of settling for under 140, the target that has long been considered acceptable – in findings that headlined the American Heart Association’s annual Scientific Sessions in Orlando, Florida.
According to the AHA, one out of every three American adults – about 80 million – has high blood pressure, increasing their risk for heart disease, stroke and other health problems.
“Getting the blood pressure lower saved lives,” said Suzanne Oparil, M.D., one of the study’s lead investigators and director of the Vascular Biology and Hypertension Program at the University of Alabama at Birmingham School of Medicine. Oparil was a member of a writing group that last year advocated for raising blood pressure targets.
“This is only one study, but it’s the best hypertension study looking at different treatment targets that’s ever been done,” she said. The landmark study was selected as one of the top 10 research advances in 2015.
The findings mean that 16.8 million Americans may become eligible for treatment or have their treatment increased, according to an analysis published online in the Journal of the American College of Cardiology.
The study followed 9,361 high blood pressure patients for just over three years – including Baldwin, who was eventually put on three blood pressure pills as part of the below-120 target group. He had some mild dizziness while golfing one summer, but after a dose adjustment reported no other problems.
Researchers found that while 65 people whose systolic blood pressure goal was below 140 died from heart disease and stroke, there were only 37 deaths among patients with the steeper goal of below 120.
The study, which was published simultaneously in the New England Journal of Medicine, also found that:
- There were 27 percent fewer deaths from any cause among patients in the lower blood pressure range (155 compared with 210).
- The risk of having or dying from a heart attack, acute coronary syndrome, stroke or heart failure fell by 25 percent (243 compared with 319).
- There were 38 percent fewer cases of heart failure in the more aggressively treated group (62 compared with 100).
High blood pressure contributed to nearly 400,000 U.S. deaths in 2013, according to the Centers for Disease Control and Prevention. Globally, the World Health Organization estimates it causes 7.5 million deaths.
“Most healthcare practitioners have been satisfied with the goal of 140, but I think with this new data, the norm will become 120 as a goal,” said Daniel Jones, M.D., a past AHA president and interim chairman of the department of medicine at the University of Mississippi Medical Center. Jones was not involved in the study.
Those enrolled in the Systolic Blood Pressure Intervention Trial, or SPRINT, were age 50 and older and had at least one other risk factor for heart disease and stroke. The dramatic results prompted investigators to stop the trial in August, nearly two years early.
Doctors have long struggled with how aggressively to treat high blood pressure, particularly in elderly patients and those with chronic kidney disease. Yet researchers found no significant differences in kidney function among participants with chronic kidney disease. And older participants, those 75 and older, appeared to benefit even more than those younger.
Systolic blood pressure is the top number in a blood pressure reading that measures pressure when the heart contracts. A reading below 120 is considered normal.
It took an average of three drugs to get blood pressure down to 120, one more than was needed to get below 140. A variety of blood pressure medications were used, including diuretics, calcium channel blockers, ACE inhibitors and angiotensin receptor blockers. Nearly all are available as low-cost generics.
Giving patients more drugs didn’t appear to increase the risk of most serious side effects, although there were more cases of some complications, including low blood pressure, fainting and acute kidney damage.
What’s still unclear is how aggressively to treat patients younger than 50 or those with diabetes, groups not included in the study.
“These findings should apply to almost everybody with high blood pressure,” said Jones, who is already treating his patients, diabetics and younger patients included, to the 120 goal. “The vast majority of my patients get there and tolerate it well.”
Jones said the SPRINT findings will influence new high blood pressure guidelines expected next fall from the AHA and American College of Cardiology. The question of how aggressively to treat diabetics will likely be addressed, said Jones, who is a member of the guidelines committee.
The same day the SPRINT results were released, the AHA and American Medical Association announced a joint initiative to help doctors and patients better control blood pressure. For now, AHA guidelines advise a systolic pressure of less than 140 for most adults with high blood pressure.
Even if the upcoming guidelines do recommend the lower 120 target, the problem is that only 53 percent of all patients even meet the currently recommended goal of below 140, according to 2014 data from the CDC.
But that national average can be misleading, said Paul Whelton, M.D., the chair of both SPRINT and the AHA/ACC guidelines committee. Some healthcare systems see control rates as high as 90 percent, he said.
“In structured environments where you’re setting targets, you’re monitoring patients carefully, you’re making sure people take their meds, you can do much better,” said Whelton, of Tulane University School of Public Health and Tropical Medicine.
The SPRINT investigators are also looking at how lower blood pressure impacts cognitive function and risk for dementia. Those results, along with longer-term outcomes on patients’ kidney function, are now being gathered.
At UAB, Oparil is now treating some patients more intensively, although she cautioned that patients still must make necessary lifestyle changes.
Editor’s Note: This story was written when high blood pressure was considered 140/90 or higher. New guidelines released in November 2017 changed the definition to 130/80.