New blood pressure guidelines: supporters get coverage, critics don’t. Why?

Michael Joyce is a writer-producer at HealthNewsReview.org and tweets as @mlmjoyce

Last month the American College of Cardiology (ACC) and the American Heart Association (AHA) released new guidelines advising that high blood pressure (‘hypertension’) be defined at 130/80 millimeters of mercury, instead of the previously widely accepted (and higher) threshold of 140/90.

The response from news organizations was massive.

Last week, when the American Academy of Family Physicians (AAFP) announced it would NOT be supporting the new guidelines there was virtually no coverage at all.

To some extent this is completely understandable. After all, the influential ACC represents over 50,000 heart specialists, the AHA is one of the most popular nonprofit charities in the United States, and heart disease is the leading cause of death worldwide. More importantly, high blood pressure is a primary risk factor for heart disease (as well as stroke, which is the second leading cause of death worldwide), and the new guidelines would mean that almost half of the adults in the United States would now qualify as having ‘high blood pressure.’ So a tidal wave of front-page news feels appropriate.

But when a major medical association like the AAFP — which has nearly 130,000 members —  refuses to endorse the guidelines AND gives compelling reasons for doing so … why is that not news?

Some historical context helps in answering that question, and shows why the question itself is extremely important.

SPRINT: Too fast with too little?

The ACC/AHA guidelines are largely a response to a study called SPRINT that was published in the New England Journal of Medicine in late 2015. SPRINT stands for: “Systolic Blood Pressure Intervention Trial.” (‘Systolic’ is the upper number of your blood pressure reading, while ‘diastolic’ is the lower number.)

We wrote extensively about the news coverage generated by SPRINT at that time and highlighted a number of concerns. Most important was that the SPRINT results were actually announced before the study was complete (or published) because the trial had been stopped early. The benefit was so clear, investigators said, that it would be unethical to continue the research. They believed the information from this “landmark study” with “potentially life-saving information” needed to be communicated to the public immediately.

Yet in that glowing preliminary announcement, they provided no supporting data, no discussion of harms, nor did they even identify which medications were used to achieve their results.

What SPRINT actually found was this: it randomized hypertensive patients over age 50 into two groups — one group was treated with more medication to reach a target systolic blood pressure of less than 120, while the other group was treated less aggressively and had a target of less than 140. The main finding was that the more intensively treated group had a  25 percent relative reduction in their combined rate of heart attacks, stroke, heart failure, and cardiovascular deaths.

What does this 25 percent reduction really mean? It means the less aggressively treated group (target < 140) had about an 8 percent chance of one of these combined outcomes over four years. The more aggressively treated group (target < 120) had about a 6 percent chance. Hence, the eye-catching 25 percent reduction. Or, looking at it another way, 92 and 94 percent of the subjects, respectively,  did NOT have one of the combined outcomes.

Why the AAFP said ‘not so fast’

When the ACC/AHA guidelines (largely based on SPRINT, but also several other studies) were released last month here’s a sampling from the dozens of headlines that were generated:

Under New Guidelines, Millions More Americans Will Need to Lower Blood Pressure (New York Times)

More than 103 million Americans will have high blood pressure under new guidelines (ABC News)

Blood pressure of 130 is the new ‘high,’ according to first update of guidelines in 14 years (Washington Post)

The take-home message from these headlines — and many more like them — is clear: millions more of us now have a disease.

Just as with lowered blood sugar thresholds for diabetes (or, ‘pre-diabetes’), and lower bone density thresholds for osteoporosis (or, ‘osteopenia’), the new ACC/AHA guidelines qualify millions of us for a ‘disease‘  we apparently did not have the day before the guidelines were released.

But the AAFP isn’t buying it. Here’s why:

  • They felt the SPRINT data were given too much weight, while contradictory studies were ignored.
  • They believe the SPRINT study did not adequately address the harms associated with treating to the lower blood pressure threshold.
  • They were concerned about conflicts of interest; specifically, that the ACC/AHA guideline panel “commissioned the principal investigator of the SPRINT trial to chair its work.”

Why this matters to you and your doctor

“There’s some point where lower is not better, and I think we’re probably getting close to that point,” says Kenny Lin MD, an associate professor of Family Medicine at Georgetown University, who says he’s worried about over-diagnosis and over-treatment with the lower threshold.

“If you’re going to make something a ‘disease’ you better have the evidence to support that, and you better have something significant to offer the patient that translates into quality of life. If my patients hit a blood pressure of 130/80 I’m already talking to them about lifestyle changes. So how does redefining this as a ‘disease’ — the new hypertension — really help them? I don’t think we should be labeling people as hypertensive — or even pre-hypertensive — unless the evidence is strong that in doing so, and treating accordingly, we’re going to truly make a difference. In this case, I don’t think we have that evidence.”

Tweet by Kenny Lin, MD

And there are other important considerations for clinicians dealing with patients with slightly elevated blood pressure. Unlike the ideal conditions used to measure blood pressure in the SPRINT trial, those in a medical office are less than ideal. Blood pressure measurements can vary depending on the measurement technique, time of day, your medications, and — of course — stress level. And if you’re not already stressed out by your health issues, just being in a medical office and meeting with a doctor can make blood pressure higher. It’s called the ‘white coat’ effect. NPR produced a very nice piece about this last month.

Point being, if you treat a blood pressure reading you presume is high — but is actually just artificially (and temporarily) elevated — you run a significant risk of dropping it far below normal. Consequences of low blood pressure include dizziness, dehydration, and passing out (especially in the elderly who are already prone to fractures from falls), and kidney damage.

Also — and this is a key part of the AAFP argument against following the aggressive ACC/AHA guidelines — family practitioners (and other primary care doctors) often find themselves treating patients with multiple medical problems, on multiple medications, having to carefully balance the risks of adding more medications, anticipating how these added drugs might interact with existing medications, and keeping in mind the cost of treatment for the patient and the health care system.

Big numbers & hype vs. evidence & nuance

It’s worth pointing out that some of the first wave of coverage of the ACC/AHA guidelines was quite good and raised some of the same objections the AAFP did. That could be one reason why some reporters did not cover the AAFP non-endorsement; they may have found it redundant to do so.

H. Gilbert Welch MD

Perhaps one of the most concise and insightful responses to the ACC/AHA guidelines was written by Gil Welch, MD. Welch is a professor of Medicine at the Dartmouth Institute for Health Policy and Clinical Research who specializes in over-diagnosis and over-treatment. It’s entitled “Don’t Let New Blood Pressure Guidelines Raise Yours” and is well worth reading.

But much of the coverage (such as these examples from USA Today, Good Housekeeping, and MSN.com) focused solely on the the huge numbers of people who would now be considered hypertensive.  There’s no mention of the possible risks/harms, other studies (such as this Cochrane Report: “Aiming for blood pressure targets lower than 140/90 is not beneficial“), or perspectives from physicians not associated with the SPRINT study.

The prevailing tone, in much of the coverage, was alarmist.

And maybe this is why the AAFP announcement didn’t generate even a fraction of the news that the ACC/AHA guidelines did. The latter referenced a major study that had already generated a tremendous buzz,  a study with big numbers that suggested millions of us might now have a disease; a disease that requires treatment, and without that treatment the consequences might be dire.

But the AAFP challenged a study that had made front page news and said it had inadequate evidence of benefits, while downplaying the harms.  They also pointed out that balancing those benefits and harms is quite nuanced, that treating or redefining a ‘new disease’  should be based on evidence, and the decision to treat should be made on a patient-by-patient basis.

I guess one of these is sexier than the other.  And just because some news organizations chose to highlight one over the other, doesn’t mean the rest of us should do the same.

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Gary Fradin

January 3, 2018 at 1:10 pm

One aspect of the Sprint study that I haven’t seen discussed so far: study participants were at increased risk of having a cardiovascular event like having clinical or subclinical cardiovascular disease. I suspect that patients with elevated BP but without such increased event risk would enjoy less benefit from following the new guidelines.