麻豆传媒

ANAHEIM -- After years of contention among professional societies over raising blood pressure targets, for the general population, including community-dwelling seniors.

The American Heart Association and American College of Cardiology, which took over from the NHLBI's Joint National Commission in 2013, released the 2017 guideline with endorsement from nine other groups with key changes to the threshold, treatment algorithm, and blood pressure (BP) measurement.

BP Classifications

Normal blood pressure remains below 120 mm Hg, but hypertension has been split into stage 1 (130/80 to 139/89 mm Hg) and stage 2 (140/90 mm Hg and higher) with different implications for treatment.

With the new target, the overall prevalence of hypertension among U.S. adults will jump to 45.6% compared with 31.9% based on the JNC7's 140/90 mm Hg threshold. That represents an additional 31.1 million people -- based on National Health and Nutrition Examination Survey data through 2014 -- for a total prevalence of 103.3 million, a simultaneously published study in Circulation indicated.

The targets were the same for older and younger adults, with the caveat that treatment decisions should be individualized for seniors with a high comorbidity burden and limited life expectancy.

The change was largely based on the SPRINT trial's finding that a target below 120 mm Hg reduced heart attack, stroke, or death in higher-risk older adults, with clear benefit and no evidence of increased risk of falls or orthostatic hypertension in elderly individuals in the trial.

But the SPRINT researchers have cautioned that the blood pressure measurements were taken with a careful automated process and in a clinical trial setting with a motivated population that differs from most clinical settings, such that their findings should not be directly applied to usual practice.

"It's much less evidenced-based than JNC8, but it's important to give advice. You can't study everything. There will never be another SPRINT," commented Suzanne Oparil, MD, who was a reviewer for the new guideline but had co-chaired the JNC8 effort that resulted in unofficial recommendations after being disbanded by the NHLBI.

That controversial guideline had recommended looser thresholds for most hypertensive individuals 60 or older, starting pharmacologic treatment when the systolic pressure is 150 mm Hg or higher or the diastolic pressure is 90 mm Hg or higher.

"You can't get a direct conversion," agreed ACC immediate-past president Richard Chazal, MD, "but it's about as 'science-y' as one can get."

The guideline writing committee selected 130/80 mm Hg as an intermediate target balancing efficacy and safety for the general population, writing committee vice chair Robert Carey, MD, of the University of Virginia in Charlottesville, explained at a press conference. Even without SPRINT, though, the evidence across the more than 900 sources reviewed for the guidelines supported that lower is better for blood pressure, the group emphasized.

BP Treatment

The blood pressure target for treatment also shifted to less than 130/80 mm Hg. However, there were key differences in recommended treatment by hypertension category.

• Stage 1 hypertension in the 130/80 to 139/89 mm Hg range was recommended for nonpharmacologic (predominantly lifestyle) therapy only unless the patient has clinical cardiovascular disease or at least a 10% 10-year risk of it based on the already in use for cholesterol treatment decisions
• Stage 2 hypertension is recommended for blood pressure medication regardless of 10-year risk or cardiovascular disease status
• Elevated blood pressure (previously prehypertension) in the 120-129 mm Hg systolic range was recommended for non-pharmacologic attention to lifestyle therapy

Lifestyle measures are weight loss, the DASH diet, reducing sodium, increasing potassium through diet, physical activity, and moderate alcohol consumption (limit one drink per day for women, two for men).

Lifestyle change is challenging, acknowledged Paul Whelton, chair of the guidelines writing committee, also speaking at the press conference. However, "we have to come to grips with it, whether somebody can achieve the goals or not we have to provide them with the information and the mechanisms to achieve those goals.”

The Circulation paper estimated a much smaller impact on prevalence of antihypertensive treatment than for overall prevalence because of the distinction by hypertension stage and risk level. It suggested an increase to 36.2%, up from 34.3% of adults with hypertension recommended for antihypertensive medication under the JNC7 guideline, representing an additional 4.2 million people.

“Yes, this will be a new challenge for clinicians as many more patients will be classified as hypertension and need treatment — both lifestyle modifications and, in some, medications,” commented American Society of Hypertension President John Bisognano, MD. “But this is a challenge that is worth taking for the right reasons and is the right approach to take.”

Carey suggested "this guideline may be a can opener" to force change and a re-commitment to lifestyle improvements.

Donald Lloyd-Jones, MD, of Northwestern University in Chicago, predicted it will be a paradigm shift in how blood pressure is treated in the U.S.

BP Measurement

The guidelines reiterated proper measurement techniques for BP measurement, including having the patient sit quietly for 5 minutes before a reading is taken.

Whelton also emphasized that the measurement should be averaged over two or three measurements taken on two or three separate office visits.

A new recommendation was for out-of-office BP measurement to confirm the diagnosis of hypertension and for titration of BP-lowering medication, in conjunction with telehealth counseling or clinical interventions.

Adoption

The guideline itself was published in Hypertension, as a rambling, that might be too much for many physicians to comb through, commented William Cushman, MD, a key SPRINT investigator.

“It’s long because it’s comprehensive,” Whelton said.

Still, "I generally think it is a very good guideline. I agree with most of recommendations," he told 麻豆传媒. "I do think more emphasis could be made that the <130/80 mm Hg goal is reasonable, but SBP <120 mm Hg may be more appropriate if BP is taken properly with an automated manometer (not with how BPs are often measured in practice).

"Realize the diastolic BP goal is based on expert opinion, not evidence. We need to continue to emphasize how BP is measured in most settings should change. You can't use a conversion factor since the difference in a sloppy BP reading and a correct technique is unpredictable in the individual patient. I think the goals are very feasible -- they are already being achieved in a high percentage in some practice settings, e.g., Kaiser. "

Endorsing organizations were the American Academy of Physician Assistants, American College of Preventive Medicine, American Geriatrics Society, American Pharmacists Association, American Society of Hypertension, American Society of Preventive Cardiology, Association of Black Cardiologists, National Medical Association, and the Preventive Cardiovascular Nurses Association.

While the American Medical Association wasn't a party to the guidelines, it is a "close" partner and will help disseminate them along with a public service advertising campaign, Whelton said.

Conflict Ahead?

Notably, primary care and diabetes care organizations that have clashed with cardiologists over blood pressure guidelines did not sign on to the ACC/AHA 2017 guideline. The American College of Physicians and American College of Family Physicians, for instance, released guidelines earlier this year loosening thresholds to 150 mm Hg systolic for people 60 and older.

While the AHA/ACC have embraced their role as setting the national guideline from the government's perspective, "I think it would be naïve for us to say we are the only guideline. We are the people that NHLBI asked to do this, so here we are. But the others exist," Chazal told 麻豆传媒.

Oparil cautioned that it may be hard for physicians to shift practice quickly. "There's not enough emphasis placed on hypertension. People will settle on any old number you get any old way, and that's not appropriate."

In order for this to really take hold it's going to have to be established as a standard for payment, she suggested.

What the timeline might be for adopting these guidelines into the performance standards of the Centers for Medicare and Medicaid Services, insurers, and even the AHA/ACC's own programs is unclear, Chazal said.

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