If you're confused about the latest recommendations for treating high blood pressure, take heart. Doctors are confused, too.
On Wednesday, a panel of specialists called the Eighth Joint National Committee published guidelines saying that many people over 60 don't need to start taking medications to lower blood pressure until it's above 150/90 millimeters of mercury.
If doctors follow the advice, they'll be less likely to prescribe blood pressure drugs to people at milder risk for heart problems.
Why? There's a lack of conclusive evidence that using drugs to get pressures lower than that will reduce a person's risk of heart attack and stroke — or increase life expectancy.
That's a substantial change from the current recommendation for all adults to get their systolic blood pressure (the first number) below 140, which is endorsed by the American Heart Association and the American College of Cardiology, two big medical professional societies. People with diabetes or kidney disease were told to go even lower, to 130.
In the new guidelines, the systolic goal for adults under 60 remains at 140, but it wipes out the lower target for people with diabetes and kidney disease.
You may wonder why there are dueling guidelines when the Joint National Committee was convened by the National Institutes of Health five years ago to come up with a single national standard. Well, there's a story behind that.
Earlier this year, the NIH decided it was going to get out of the guidelines business, handing it over to the professional societies.
That left the Joint National Committee orphaned. Figuring that joining up with the AHA and the ACC would substantially delay release, the group published its own guidelines in JAMA, the journal of the American Medical Association.
"Producing guidelines in the United States has become increasingly more complicated and contentious," one of three editorials accompanying the guidelines noted.
Indeed, one reason that NIH may have bailed is because the process has become so politicized. The Obama administration came under serious heat from the American Cancer Society and patient groups for a 2009 decision to raise the recommended age to start mammograms to 50. And in 2006 the Infectious Diseases Society of America was sued by the state of Connecticut for recommending against long-term antibiotic treatment for Lyme disease.
"This is a funny situation," says Dr. Harlan Krumholz, a cardiologist at the Yale School of Medicine. "What's good here is that they're really adhering to evidence and being honest about what we don't know. I think in earlier guidelines there's been this false sense of security."
People with very high blood pressure, like 160 or 170 systolic and above, clearly benefit from aggressive treatment with medication to lower blood pressure, Krumholz says. But the evidence shows that people with moderately elevated blood pressure don't gain the same reduction in risk of heart attacks and stroke, even if they manage to lower their numbers.
"We should be going after people with marked elevation to make sure they're all getting treated," Krumholz told Shots. "People with mild risk, you have to be honest with them, and say, 'I don't know if I'm doing much for you.' "
The new guidelines also reflect the fact that after a point it becomes increasingly difficult to push blood pressure lower with drugs.
"It's easy to bring someone from 170 to 150," says Dr. Domenic Sica, a nephrologist at Virginia Commonwealth University, and president-elect of the American Society For Hypertension. "But if you're on three drugs and you're at 150, you may need three more drugs to get from 150 to 130."
The low odds of making that big a change can discourage both patients and doctors. "It's a daunting task," Sica tells Shots. Having more reasonable evidence-based goals may encourage people to work with their doctors to come up with a liveable plan, including healthful eating, exercise, and perhaps less medication and blood pressure monitoring.
But for now, patients and doctors will have to decide what guidelines they like best.
"It's a conundrum," Sica notes, adding that it will also affect how insurance companies rate doctors based on performance, and how they reimburse. "Do they really think insurance companies are going to accept 150 over 90?"
If this isn't confusing enough for you, stay tuned. Next year the AHA and the ACC are scheduled to release their own updated guidelines.