How Low Should You Go? Big Study Sheds Light on Best Blood Pressure
By the Editors of Yahoo Health
Details were revealed Monday from a landmark federal study that challenges decades of thinking on blood pressure, giving a clearer picture of plusses and minuses of more aggressive treatment.
The study was stopped in September, nearly two years early, when it became clear that lower pressure for most people over 50 helps prevent heart problems and deaths, but side effects and other key details were not disclosed.
Full results came Monday at an American Heart Association conference in Orlando and were published online by the New England Journal of Medicine, along with a dozen commentaries in three science journals.
"Overall, we deemed that the benefits far outweigh the risks” of aiming lower, said one study leader, Dr Paul Whelton of Tulane University.
One in 3 US adults has high blood pressure, a reading of 140 over 90 or more. Normal is under 120 over 80. Detailed data unveiled at the AHA meeting showed additional benefits of intensive lowering of systolic pressure — the top number in a blood pressure reading — to 120 or below, despite the commonly used medical target of simply below 140 over 90.
“We thought 140 was good enough,” study co-author George Thomas, MD, director of Cleveland Clinic’s Center for Hypertension and Blood Pressure Disorders, told Yahoo Health . He says that the results are surprising given that they’re so different from the current recommended guidelines.
“What we’ve been aiming for was 140,” he says. “We didn’t have any evidence to suggest otherwise.” Thomas notes that 120 is considered a “normal” systolic blood pressure for most people, but the goal has always been to get people with high blood pressure to 140.
The findings are so significant because high blood pressure is a leading risk factor for various health issues, including heart disease, stroke, and kidney failure. According to the NIH, an estimated one in three people in the US has high blood pressure.
Nicole Weinberg, MD, a cardiologist at Providence Saint John’s Health Center in Santa Monica, Calif., told Yahoo Health that the new findings are “wonderful” because many clinicians have noticed better results in heart muscle and artery function when high blood pressure patients can get closer to 120.
“But when the guidelines say that it’s 140, you’re always fighting an uphill battle with patients,” she says.
More than 9,300 people were enrolled. Half got two medicines, on average, to get their top blood pressure reading below 140. The rest got three drugs and aimed for under 120.
One complication is that study enrolled people with a systolic blood pressure of 130 or more, somewhat muddying the notion of who needs treatment.
After one year, 1.65 percent of the lower pressure group had suffered a major heart problem or heart-related death, compared to 2.2 percent of the others, a 25 percent lower risk. About 3.3 percent of the lower pressure group died, versus 4.5 percent of the others, a 27 percent lower risk.
Too-low blood pressure, fainting episodes and more worrisome, kidney problems were 1 percent to 2 percent higher in the lower pressure group. Yet falls that cause injury due to lightheadedness were not more common, as had been feared especially for older people.
The risks were considered well worth the benefits of a lower risk of heart trouble and death.
DOES IT APPLY TO ME?
The study involved people over 50 whose top reading was over 130. People with diabetes were excluded, so the results do not apply to them. The results also may not apply to people with previous strokes, the very old, those with severe kidney disease or people already taking a lot of different drugs, said Dr James Stein, who heads the high blood pressure program at the University of Wisconsin in Madison.
People who start with a high top reading, such as 170 or 200, also may not do well trying to drop so low so suddenly, Dr Murray Esler of Baker IDI Heart and Diabetes Institute in Melbourne, Australia, wrote in a commentary in the journal Hypertension.
GUIDELINES MAY CHANGE
The new study “makes sense and is a major advance,” Stein said. “Time to fix the guidelines,” which come from many groups and aim for a top number of 130 to 150, depending on age and other factors, such as whether the patient has diabetes.
THE BOTTOM LINE
Only half who know they have high blood pressure have it under control now. From a public health standpoint, improving that situation may be more important than having a new number as a target.
“If we lower the goal … you’ll see more and more people getting to lower pressure,” said Dr Daniel Jones of the University of Mississippi, a heart association spokesman.