US Hypertension Guidelines: Cutting Through the Controversy

May 23, 2018

It has been 6 months since the release of the updated American College of Cardiology (ACC)/American Heart Association (AHA) hypertension guidelines that lowered the blood pressure goal and threshold for diagnosis of hypertension to 130/80 mm Hg.

And while this new target has been welcomed by most in the cardiology community — with data published today suggesting large benefits in reducing cardiovascular events and deaths if the new targets were achieved — organizations representing family practitioners and general internists are still unhappy. 

How can practicing physicians navigate their way through these mixed messages and provide the best care for their patients? Medscape Medical News spoke to the major players involved in the argument and several outside experts in the field to gauge opinion on the issues as they stand now.

The AHA/ACC released the new hypertension guidelines in November 2017, with partner organizations including the American Academy of Physician Assistants, the American College of Preventive Medicine, the American Geriatrics Society, the American Pharmacists Association, the American Society of Hypertension, the American Society of Preventive Cardiology, the Association of Black Cardiologists, the National Medical Association, and the Preventive Cardiovascular Nurses Association.

The major changes in the document included a new classification system, with hypertension being diagnosed at a blood pressure of 130 mm Hg systolic; new recommendations on how blood pressure should be measured; lowering the blood pressure target from 140/90 to 130/80 mm Hg for all, including the elderly; and incorporating underlying cardiovascular risk into treatment decisions for those with systolic pressures of 130 to 139 mm Hg.

An analysis published May 23 in JAMA Cardiology estimates that the new definition of hypertension means that 45.4% of the US population (105 million adults) are now considered hypertensive, up from 32.0% (74.1 million) according to the definition in the 2014 guidelines. That's an increase in the number of US adults with a diagnosis of high blood pressure of 31 million, with 11 million of these qualifying for antihypertensive treatment, conclude the researchers, with senior author Jiang He, MD, PhD, from the Tulane University School of Public Health and Tropical Medicine in New Orleans, Louisiana.

Using data from the National Health and Nutrition Examination Survey, antihypertensive clinical trials, and population-based cohort studies, investigators calculate that achieving the 2017 hypertension guideline treatment goals in every individual would reduce major cardiovascular events by an additional 340,000 and total deaths by an additional 156,000 annually compared with the 2014 guideline. But this would also lead to an increase of 62,000 hypotension and 79,000 acute kidney injury or failure events.

An accompanying editorial, coauthored by Lawrence J. Fine, MD, DrPH; David C. Goff, MD, PhD; and George A. Mensah, MD, all from the National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, concludes that these latest data help us "understand the possible benefits of more effective treatment and prevention of hypertension."

And an editor's note by Clyde W. Yancy, MD, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, deputy editor of JAMA Cardiology, and Gregg C. Fonarow, MD, Ronald Reagan University of California Los Angeles Medical Center, concludes that the new data show that the benefit of hypertension therapy per the 2017 hypertension guidelines "meets the bar to qualify as a robust prevention strategy." 

"Given that benefits, especially fewer cardiovascular events and fewer deaths in those at higher cardiovascular risk, now clearly exceed potential harms, barriers to implementation should fall," Yancy and Fonarow write. "It is our opinion that the time is on us to implement."

But while the guidelines have been endorsed by many other professional societies, the American Academy of Family Physicians (AAFP) and the American College of Physicians (ACP) have refused to give their support. Their main objections relate to the new hypertension classification and blood pressure target of 130 mm Hg systolic, with specific concerns about the elderly.

The AAFP and ACP assert that the ACC/AHA guidelines committee gave too much weight to the SPRINT trial and not enough attention to systematic review of other evidence. They also claim that "the harms, costs, and complexity of care associated with the new target do not justify the presumed benefits."

ACP and AAFP have issued their own guidelines for older adults (age 60 years and older) recommending a target systolic pressure less than 150 mm Hg, or less than 140 mm Hg in selected persons at high cardiovascular risk, which they conclude "provides an optimal balance of benefits and harms." They also continue to endorse the 2014 guidelines developed by the Eighth Joint National Committee (JNC 8). 

"The new guidelines rely heavily on one trial — SPRINT — but that trial included patients with a significantly increased cardiovascular risk that can't be generalized to lower-risk individuals," AAFP President Michael Munger, MD, told Medscape Medical News. "Systematic reviews of other studies didn't get the same weight, and they didn't take into account adequately the burdens and harms of lower blood pressure, such as falls and dizziness."

With 130 mm Hg as the threshold for a hypertension diagnosis, Munger added, "millions more people will now be labeled as having a medical condition without any evidence to support this. We should be preaching lifestyle to everyone anyway regardless of their blood pressure. If someone has a blood pressure of 132/80 mm Hg and no other risk factors or family history, do they really need to be worried about having hypertension? I don't think so."

Timothy J. Wilt, MD, a coauthor of the ACP/AAFP guidelines, added: "We believe that initiation of pharmacologic therapy at or above a BP [blood pressure] of 130/80 mm Hg and treatment targets less than 130/80 mm Hg in a broad population of older adults are not supported by evidence and may result in low-value care by unnecessarily labeling and treating a large segment of the population."

Chair of Guidelines Committee Responds

Chair of the ACC/AHA hypertension guidelines committee, Paul Whelton, MD, Tulane University School of Public Health and Tropical Medicine, told Medscape Medical News they had hoped to create some consensus. "I wish the ACC/AHA efforts could have brought all the professional societies together to develop one guideline, but that was not to be. People tend to focus on the differences rather that what we agree on."

"We made a strong effort to consult outside groups on the guidelines," he said. "We received over 100 comments and responded to all of them. But we are in the position that there are a number of different guidelines and we have to deal with that. My hope is that we find some commonalties."

In an interview, he responded to the specific issues raised by the ACP/AAFP.

"To say that we haven't included enough other data outside of SPRINT is a ridiculous statement," Whelton said. "I sometimes think people have an opinion and haven't read our document at all."

"We looked at all the world literature in detail," he asserted. "Many other meta-analyses have shown benefits of lowering systolic pressure right down to the early 120s, and when we were discussing SPRINT, the three of us on the guidelines committee who were involved in that trial stepped away so there was no conflict of interest."

He pointed out that the SPRINT trial showed a dramatic benefit of intensive blood pressure lowering both on the composite endpoint and on all-cause mortality in the whole trial and specifically in the elderly subgroup. "Mortality data is hard to get wrong — people are either alive or dead."

On the claim that they didn't give enough weight to harms of intensive blood pressure lowering in SPRINT, Whelton said, "Of course we looked at adverse events. We investigated all serious adverse events extremely thoroughly."

In SPRINT serious adverse events did not differ between the two groups, he noted. "There was an increase in hypotension and some electrolyte changes in the intensive group, but these did not have serious biological consequences. We looked very carefully at the very frail elderly, but still the benefits of intensive blood pressure lowering vastly outweighed the adverse events.

"We want to be sensible and careful, but getting caught up in the possibility of adverse events should not prevent us from doing the right thing for older adults. You have to ask, Would you prefer the patient to have a stroke or risk an electrolyte imbalance?

"The entire committee was very comfortable with the 130 mm Hg target, as well as the evidence review committee, which was firewalled from us," he added. "We all thought 130 was a very safe and reasonable target."

Whelton said in general he has had a good response to the guidelines from family practice doctors. "They have said after listening to us present the guidelines that although it will make their life more complicated, it does seem to be the best thing for the patients."

Evidence for Low-Risk Individuals

One of the major points of disagreement centers on whether there is enough evidence to recommend a 130–mm Hg target for low-risk patients.

Supporting the ACP/AAFP stance, Michael LeFevre, MD, Department of Family and Community Medicine, University of Missouri School of Medicine, Columbia, who was part of the previous JNC 8 hypertension guidelines committee, said he is particularly concerned about labeling everyone with pressures above 130/80 mm Hg as hypertensive even if they have no other risk factors.

"That is a lot of people and that label is not benign — it has serious consequences," he commented to Medscape Medical News. "It can affect their medical insurance and their life insurance, and I don't think it is justified by the science. The SPRINT trial was a selective group — the vast majority were higher-risk patients already taking antihypertensive medications. They have extrapolated this data to the group at low risk with systolic pressures in the 130 to 140 range without treatment. We don't have the science to support that."

Paul James, MD, a primary care doctor and first author of the previous JNC 8 guidelines, has a similar view.

"The new ACC/AHA guidelines represent a real challenge for the community to accept. They may be evidence informed but they are not evidence based," he said.  

"The ACC/AHA guidelines have taken the SPRINT results in a relatively high-risk population and extrapolated them to younger, healthier people," James said. "We feel the guidelines will lead to people who are healthy being overmedicated without fully examining the benefits and risk of treatment."

James notes that a systolic pressure of 130 to 139 mmHg — now defined as hypertension in the new guidelines — used to be called "pre-hypertension."

In family practice, pre-disease is what we refer to as health. Dr Paul James

 

"In family practice, pre-disease is what we refer to as health," he said. "To what end does it help to label people earlier and earlier with a diagnosis causing great levels of worry and use of medications that we don't know have any benefit? The American Cancer Society wants us to label everyone as pre-cancer. Now the AHA wants us to label everyone as pre-heart disease. I would not be against this if we had studies to support it, but I want to see the science that validates this."

Whelton acknowledges it is "tough" in the lowest-risk group, as it would require "enormous" trials to demonstrate a benefit on outcomes. "But we know people with blood pressures of 130 to 139 are at increased risk of cardiovascular events compared to those with lower pressures, so they are not 'pre-' anything," he said. "And we are only recommending lifestyle changes for this group. It is a surprise to me that anyone would think lifestyle change would not be beneficial to them."

Hypertension experts polled on this sided with Whelton.

William White, MD, past president of the American Society of Hypertension and chief of the Division of Hypertension and Clinical Pharmacology at UConn Health, Farmington, Connecticut, acknowledged there is the argument that SPRINT had a generally quite high-risk population.

"The guidelines have extrapolated SPRINT data to lower-risk patients for public health reasons," he said, but added, "I think that is a reasonable thing to do. So you could say that the guidelines are not strictly 100% based on data from randomized controlled trials but they are well intentioned from a public heath view."  

"The conflict here is one between cardiologists and internists," White said. "Cardiologists like to lower blood pressure aggressively. Internists don't. We all know what happens in general clinical practice — if you give them a target of 130 they will be happy with 135. If you ask them to aim for 140, then they think 145 is okay."  

The conflict here is one between cardiologists and internists. Cardiologists like to lower blood pressure aggressively. Internists don't. Dr William White

 

"Yes, it is a bit silly that half the population is now labeled as hypertensive," he conceded, "but the guidelines were careful to say that in those 130 to 139 systolic and at low cardiovascular risk, then they don't need drug therapy."

Michael Weber, MD, professor of medicine at SUNY Downstate College of Medicine, New York City, and editor of the Journal of Clinical Hypertension, put forward a similar argument. 

"Perhaps the classification of hypertension at 130 mm Hg may be a bit on the aggressive side," he said. "I don't think I know too many people who now don't have hypertension. But we recognize that cardiovascular events increase with increasing blood pressure. Where we draw the line and diagnose hypertension is somewhat arbitrary, but good clinicians can figure out what to decide for their patients."

Labeling hypertension at 130 mm Hg encourages treatment of patients at higher cardiovascular risk and may encourage those at lower risk to think more about their lifestyle, Weber added. "Surely this is beneficial."

"You could probably get by not treating younger people with pressures of 140 to 145, but why wouldn't you want to treat anyone in this range?" he pointed out. "The modern drugs are very well tolerated; side effects are very rare in most patients. Why wouldn't you want to provide cardiovascular protection before your patients have an event?"

"The fact is, when the target was 140, many patients were not treated anywhere near adequately," Weber added. "If we target 130, then at least more people will get to 140. I'm happy with the guidelines — and they are only guidelines — they do state that individual doctors should discuss the situation with the individual patient and share the treatment decisions."

George Bakris, MD, the University of Chicago Medicine, Illinois, and coauthor of a "Perspective" piece on the AHA/ACC guidelines in the New England Journal of Medicine, also supports the 130 mm Hg target.

"I think the ACC/AHA have produced an amazing preventative health document, but most physicians are not thinking about preventative care — they focus more on treating acute conditions. I think the ACP/AAFP are over-reacting to the 130 mm Hg threshold/goal, as the guidelines are not advocating using drug therapy in low-risk patients under 140 mm Hg."

"The ACP/AAFP have a mantra of keeping costs down and are always quite conservative," he added. "There is a similar argument going on between them and the American Diabetes Association (ADA) over glucose targets."

Still, in his Perspective article, Bakris acknowledges that it may be "problematic" to lower the threshold for hypertension for primary care physicians. 

"Some people with blood pressures of 130 to 139/80 to 89 mm Hg who are at higher cardiovascular risk may benefit from earlier intervention, but though such a broad-brush approach may be fine from a public health perspective, it could overburden our primary care physician workforce," he writes.

"Proper blood pressure measurement is critical but time consuming," he points out. "The unintended consequence may be that many people, now labeled as patients with hypertension, receive pharmacologic therapy that's unlikely to provide benefit given their low absolute risk, and they may therefore experience unnecessary adverse events."

What About Diabetes?

Bakris also chaired the committee for the latest ADA blood pressure guidelines, which he said have "a small discrepancy" with the AHA/ACC guidelines.

"The ACC/AHA recommends a target of 130/80 for all whereas the ADA recommends 140/90 for most people with diabetes, but 130/80 for those at high risk of cardiovascular disease, with a strong emphasis on individualization of treatment for each patient," he explained.

More information on reasons for the differences with the AHA/ACC guidelines were set out in a recent "Viewpoint" article in JAMA that Bakris coauthored with Ian H. de Boer, MD, University of Washington, Seattle, and Christopher P. Cannon, MD, Harvard Medical School, Boston, Massachusetts.

"In diabetics, the same magnitude of benefit of very low blood pressure doesn't seem to constantly be seen compared to nondiabetics," Bakris said. "Sometimes in diabetics with extensive microvascular disease, lowering blood pressure can mean some tissues are not perfused adequately, so we are being a bit more cautious, but I would say the two sets of guidelines are 97% in agreement."

Whelton said the difference of opinion comes from the fact the ACC/AHA guidelines would classify all people with diabetes as being at high risk or likely to progress to being high risk.  

"The query in diabetics comes from the ACCORD trial, which was difficult to interpret. It had very wide confidence intervals, which included the possibility of a large benefit or a small harm from intensive blood pressure lowering, so it didn't answer the question," he said. "But by putting the two trials together they are absolutely consistent with each other."   

Different Targets for Older Adults?

The other major point of disagreement with the ACC/AHA guidelines and the AAFP/ACP is targets for the elderly.

"Our literature review of all the world evidence shows that reducing blood pressure to lower than 150 mm Hg in older people does not reduce the risk of cardiovascular events much further but substantially increases the risk of side effects," Munger said.

LeFevre acknowledged SPRINT showed a benefit with lower pressure in elderly, "but that was just one trial," he said. "The target of 150 for those aged over 60 recommended by AAFP/ACP is in line with the literature we have, but they do say that for high-risk individuals there is an option to intensify treatment to a goal of 140. There are older people for whom a goal of 140 is a good idea but these should be selected on a case by case basis."

Whelton responded that the SPRINT results are clear for the older population. "The results in the elderly were more pronounced than in the whole population. And our recommendation is not just based on SPRINT — there are also several meta-analyses of other studies which reached the same conclusion — that systolic blood pressure less than 130 was good for all ages."

White said the AAFP/ACP position is "a terrible mistake." "People were shocked when they made this statement," he said. "In many cohort studies involving many tens of thousands of patients, cardiovascular events are much lower with blood pressures well below 130. They are going back decades to when we believed higher pressures were better for older people. To go back there would cause many more people to suffer strokes and heart attacks. That is unconscionable."

He added: "I understand there is some concern about going too low in older people but SPRINT discounted that. That trial included a large population of older people and they did very well going right down below 130. Ignoring that information is definitely a problem."

Weber also fervently defended the ACC/AHA guideline on this. "The AAFP/ACP are wrong about targets for older adults," he said. "Other trials have also supported similar targets in older people and younger people. The single biggest risk factor for a cardiovascular event is age — just by being 75 years old, even if you are fit enough to climb mountains, puts you way over the top in terms of the risk of a major cardiovascular event. It is absurd to say that any old person is at low risk. And the older people got the biggest benefits in SPRINT. You just can't fight that data."

Weber pointed out that the other criticism of SPRINT made by some is that they did not give due consideration to side effects of medication,  such as syncope, which can occur more frequently in older people. But he stressed that the mortality benefit trumps concerns about adverse effects every time. "Yes, some patients may experience some dizziness but then you have to ask: Would you rather work through this problem or would you rather take the risk of a fatal event?"

Bakris raised one caveat. "Most elderly people do very well with systolic pressures in the 120s and 130s, but there might be some with isolated systolic hypertension whose diastolic pressure would be too low if aiming for these low systolic pressures. This can affect perfusion to the brain and cause fatigue and memory problems, so I think it would be helpful to point that out and advise not going any lower if this occurs. Other than that, I'm fine with the 130 target for the elderly as well."

"There was a major furor when the AAFP/ACP came out with their hypertension guidelines for older adults, which have largely been dismissed by the cardiology community," Bakris added.

Risk Stratification: Is the Threshold Correct?

Another new feature of the ACC/AHA guidelines is inclusion of risk stratification for individuals in the 130 to 139 mm Hg systolic range, with drug therapy recommended for those with a 10-year risk for a cardiovascular event over 10% and lifestyle advice for those under this risk threshold. This has also generated some discussion.

A group led by Robert Phillips, MD, Houston Methodist, Texas, report a study, published recently in the Journal of the American College of Cardiology, that re-analyzed the SPRINT results, taking into account both cardiovascular events and adverse effects of lower blood pressure targets. They found that patients who benefited most from intensive blood pressure lowering were in the top two quartiles in terms of cardiovascular risk, with a 10-year cardiovascular risk of 18.2% or above. 

"The new guidelines have incorporated risk stratification for the first time, which we agree with, but they advise using medication to treat everyone with a systolic blood pressure of 130 to 139 with a 10-year cardiovascular risk of 10% or more," Phillips commented to Medscape Medical News. "Our data suggest that a 10-year risk of 18% would have been a better point at which to recommend treatment."

"The group in between 10% and 18% 10-year risk represents several million people in the US," he said. "That's a lot of people. We believe that for those people a goal of 140 systolic is more appropriate. That would spare millions of people taking unnecessary medication with the accompanying unnecessary worry."

But Whelton was not impressed with this study, which he described as a "lazy and inappropriate analysis."

"It is ignoring the fact that serious adverse events were the same in the two groups, and it is misleading to give equal weighting to outcome events, such as all-cause mortality, stroke, and heart failure hospitalization, and adverse events, such as syncope and electrolyte disturbances. There is nothing equal about death and an electrolyte disturbance," he said.

"We calculated out risk threshold for treatment recommendation by extrapolating from clinical trials," Whelton added. "The concept of risk stratification is very important, and this is the first time it has been incorporated into US hypertension guidelines. Getting a risk prediction calculator into electronic health records for the clinician to use is a huge achievement. It might not be the perfect risk assessment tool, but it is a very good start." 

The risk calculator they used is the same as that used for lipid therapy, he noted, because they didn't want to complicate things by asking clinicians to do more than one risk analysis. "It is also very well validated in US cohorts," he said.

More Collaboration Called For

Rather than fighting over differences, Whelton is calling for the various different professional associations to be more collaborative. 

"We should be seeking out common areas of practice," he said. "We agree that we should be treating most people with blood pressure over 140/90, and that we should consider cardiovascular risk. Surely everyone should also agree that we need better ways of measuring blood pressure — the way we do at the moment with just one quick measurement is appalling. It's like running a lab without any quality control or flying a plane without a license."

But Weber thinks collaboration of all parties is unlikely. "There is an undercurrent of anger and personality clashes between the two sides here. We will have to live with this impasse, but the good news is that most primary care physicians in the United States are strongly focused on controlling their patients' hypertension and will know how to work through this controversy."

He noted that in only a few weeks' time, the new European hypertension guidelines will be announced at the European Society of Hypertension meeting in Barcelona, Spain. "Let's see what the Europeans come up with — I suspect they will be largely supportive of the strong ACC/AHA position."

"Ultimately, guidelines are recommendations that good clinicians interpret and use in the best interests of their patients — they are not cast in stone!" Weber concluded.  

Whelton was on the steering committee of the SPRINT trial. LeFevre was a member of the JNC 8 panel that developed the 2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults and currently serves on the Science Advisory Panel of the AAFP. He was not involved in the AAFP's decision to not endorse the ACC/AHA hypertension guideline. James was first author of the JNC 8 guidelines. White receives funding from the US National Institute on Aging for work on hypertension in older persons and is chair of the steering committee for the NIRVANA-HTN trial in treatment-resistant hypertension, which is sponsored by Novartis Pharmaceuticals. Bakris is the co-chair of the American Diabetes Association Blood Pressure Consensus Report.

JAMA Cardiol. Published online May 23, 2018. Abstract, Editorial, Editor's Note

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