A new and long-anticipated guideline for diagnosing and managing hypertension by the American College of Cardiology, the American Heart Association, and nine other collaborating societies was finally released last fall. What happens now?
Will the top-line, seismic change that the new guidelines called for – treating many patients with hypertension to a blood pressure below 130/80 mm Hg – become the standard of care for U.S. medicine? And what about the several other novel steps the guideline calls for including more careful and methodical measurement of blood pressure with greater emphasis on out-of-office blood pressure monitoring, increased reliance on lifestyle interventions, running a formal calculation of a patient’s cardiovascular disease risk to identify patients who warrant drug treatment, development and attention to a care plan for each hypertensive patient, and a team approach to management?
In this two-part feature, a potential revolution in care will be explored.
ACC/AHA guidelines: More than just numbers
The ACC and AHA guideline (J Am Coll Cardiol. 2017 Nov 13. doi: 10.1016/j.jacc.2017.11.006 ) is “comprehensive. It addresses many issues around hypertension, not just what is a good [blood pressure] number and a bad number. This is important because this type of document has not existed for quite some time,” said Donald E. Casey Jr., MD , a member of the guideline-writing panel, an internal medicine physician, and chief clinical affairs officer at Medecision in Wayne, Pa.
“This is the first time that a [blood pressure] guideline has explicitly led with a strategy of calculating a person’s risk using the ACC/AHA risk calculator . It’s not ‘what is your blood pressure?’ but ‘what is your risk?’ This is not a one-size-fits-all guideline.”
The biggest wild card when handicapping the odds that the new guideline will take hold is how U.S. primary care physicians, the clinicians who stand on the front line of U.S. medicine for diagnosing and treating hypertension, respond. Their reaction remained an open issue during the weeks following release of the new guideline, in large part because its headline feature, the treatment target of less than 130/80 mm Hg, is at odds with what a competing guideline released just 8 months earlier from the American College of Physicians (ACP) and the American Academy of Family Practice (AAFP) called for, namely, a hypertension treatment target of less than 150/90 mm Hg in patients aged 60 years or older who need drug intervention (Ann Int Med. 2017 March 21; 166[6]:430-7 ).
Primary care pushes back
Although a significant part of the ACC/AHA guideline has either received endorsement from or is likely acceptable to the primary care organizations, including recommendations for improved blood pressure measurement and the key role for healthy lifestyle interventions, these two sides seem irreconcilable on the core issue of what is the target blood pressure for many patients when they are on antihypertensive drugs.
That inference turned into a reality in mid-December when the AAFP released a scathing critique of the ACC/AHA guidelines, and reaffirmed its endorsement of the controversial blood pressure target set by the panel appointed to the Eighth Joint National Committee (JNC 8), which in 2014 recommended a treatment target when using antihypertensive medications of less than 150/90 mm Hg for patients aged 60 years and older (JAMA 2014 Feb 5; 311[5]:507-20 ).
In its December critique, the AAFP said it saw several problems with the ACC/AHA recommendations including lack of a systematic evidence review for most recommendations, overreliance on evidence from the SPRINT trial (N Engl J Med. 2015 Nov 26; 373[22]:2103-16 ), and “intellectual conflicts of interest” by several members of the ACC/AHA guideline panel, most notably the chair of the panel, Paul K. Whelton, MD , who also served as chair of the SPRINT steering committee.
A few weeks later, in late January, the ACP issued its own rejection of the core blood pressure target of the ACC/AHA guideline (Ann Int Med. 2018 Jan 23. doi: 10.7326/M17-3293 ). “Are the harms, costs, and complexity of care associated with this new target justified by the presumed benefits of labeling nearly half the U.S. [adult] population as unwell and subjecting them to treatment? We think not,” declared the statement from the ACP’s Clinical Guidelines Committee.
Although this ACP statement praised the ACC/AHA guideline in its “emphasis on the importance of blood pressure measurement technique and lifestyle changes,” it added that the guideline also “falls short in weighing the potential benefits against potential harms, costs, and anticipated variation in individual patient preferences.”
The statement went on to cite three specific flaws in the notion of using antihypertensive drugs to treat patients to less than 130/80 mm Hg: 1. Clinical trial results have not shown consistent evidence for benefit from a systolic blood pressure target of less than 130 mm Hg in older adults with diabetes or kidney disease. 2. Benefits are often overestimated and harms often underestimated when trial findings are applied to broad primary care populations. 3. No evidence from randomized controlled trials support a diastolic blood pressure target of less than 80 mm Hg.
“I think the new [ACC/AHA] guidelines are unlikely to be widely adopted by primary care physicians [PCPs]. I suspect that the responses of the ACP and AAFP to the guidelines will have an important impact on whether PCPs ultimately decide to change practice,” commented Jordana B. Cohen, MD , a nephrologist and hypertension researcher at the University of Pennsylvania in Philadelphia. “PCPs have long expressed exhaustion with constantly changing, overly complex guidelines. The frequently oscillating hypertension guidelines risk jeopardizing the trust of practicing PCPs with regard to hypertension guidelines,” she said in an interview. Dr. Cohen published an assessment of the ACC/AHA guideline soon after its release (Ann Int Med. 2017 Dec 5. doi: 10.7326/M17-3103 ).
Dr. Cohen said she agreed with a general target blood pressure of less than 130 mm Hg, while qualifying it with some caveats, and added that she did not agree that most patients should be treated to less than 80 mm Hg diastolic. “I will be less inclined to push for aggressive management in patients who are poorly functional, or those with many drug side effects or issues with polypharmacy. And given the evidence from ACCORD (N Engl J Med. 2010 April 29; 362[17]:1575-85 ), I do not plan to apply stricter blood pressure control in patients with diabetes, and also not in patients with nonproteinuric chronic kidney disease.”
“There are many caveats and obstacles to making the new ACC/AHA guidelines work. If we could really fine-tune blood pressure, the guidelines would probably save lives, but it will be extremely difficult to do in the real world,” commented John P.A. Ioannidis, MD , professor of medicine and a preventive medicine specialist at Stanford (Calif.) University. What the ACC/AHA guidelines call for “is largely impossible to do currently, so I’m very skeptical that the benefits will outweigh the harms. The AAFP position is more pragmatic. But it creates a head-to-head guideline competition, and it will create confusion in the ranks of primary care physicians and in patients. I think the more lenient blood pressure targets suggested by the AAFP will be closer to what most practices will aim for and achieve,” said Dr. Ioannidis in an interview. He has also published a commentary on the ACC/AHA guidelines (JAMA 2018 Jan 9; 319[2]:115-6 ).
Dr. Ioannidis said in his JAMA commentary that the panel that wrote the ACC/AHA guidelines had “no conflicts of interest.” In the interview, he took issue with the AAFP’s objection to intellectual conflicts among some panel members.
“The concern raised by the AAFP is legitimate. Most cardiovascular medicine guidelines until now have been problematic because of overt financial conflicts of interest. Here is a guideline with no obvious financial conflicts of interest.” The ACC/AHA guideline document shows that across the entire list of guideline panel members no one had any financial disclosures.
“Intellectual conflict exists in every person who knows something about a certain field,” continued Dr. Ioannidis. “The only way to get rid of intellectual conflicts is to recruit people who know nothing about the subject. That’s not advisable. The problem is not an intellectual conflict in any one person – everyone has an intellectual conflict. The problem is stacking the membership of a guideline panel in a way that all or almost all have expressed a strong preference for some policy or strategy so that the guideline is bound to stick with this approach. While several members of the ACC/AHA had an intellectual conflict, I doubt there is a case for saying the entire committee was stacked.”
Goals for older adults: Irreconcilable differences?
How was it that the ACC/AHA guideline and the ACP/AAFP guideline reached such disparate conclusions about the appropriate blood pressure treatment target for patients aged 60 years or older?
“The SPRINT trial is really the only study that has demonstrated benefit across outcomes from aggressive blood pressure control compared with moderate control. SPRINT was a large and important trial, but the inconsistency in results across studies was interpreted by the ACP/AAFP as a reason to cautiously apply its results to individual patients,” commented Devan Kansagara, MD , an internal medicine physician at the Portland VA Medical Center who was also the senior author of the literature review that formed the basis of the ACP/AAFP guideline (Ann Int Med. 2017 March 21; 166[6]:419-29 ) and also a coauthor of the ACP’s official comment on the ACC/AHA guideline published in January.
“A critical difference between the two guidelines stems from how potential [treatment] harms and patient values and preferences were considered. Our review and the ACP/AAFP guidelines extensively considered harms and treatment burden associated with lower blood pressure treatment targets. Lower targets did not increase the risk for fractures, falls, or cognitive declines, but they were associated with more symptomatic hypotension, syncope, and greater medication burden. The ACP/AAFP believed that there is likely to be significant variation in how individual patients might weigh the small potential benefit of aggressive blood pressure control against the potential harms and treatment burden. The ACC/AHA guidelines and the systematic review on which they were based did not include an assessment of harms,” Dr. Kansagara said in an interview. Dr. Casey maintained that the ACC/AHA literature review did consider potential harms from treatment.
“The ACC/AHA guidelines also considered results from observational studies. The ACP/AAFP did not. A number of studies show that progressively higher levels of blood pressure are associated with higher rates of cardiovascular disease events and mortality. But some observational studies showed that blood pressures in the low to low-normal range are associated with higher mortality. The problem with observational studies is that there are many reasons why a population with higher blood pressure may have worse outcomes. That does not mean that using medication to reduce blood pressure will improve outcomes.”
Other experts noted that while the ACP/AAFP data review and guideline took the SPRINT results into account, their review occurred too soon to also include two other important analyses that came down in favor of the less than 130/80 mm Hg target and were included in the ACC/AHA review: A meta-analysis of 42 trials with more than 144,000 patients that showed patients treated to a systolic blood pressure of 120-124 mm Hg had significantly fewer deaths and cardiovascular disease events compared with patients with higher achieved blood pressures (JAMA Cardiology, 2017 July; 2[7]:775-81 ); and a second meta-analysis of 17 trials with more than 55,000 patients that showed a target systolic pressure of less than 130 mm Hg produced the best balance of efficacy and safety (Am J Med. 2017 June; 130[6]:707-19 ).
The bottom line, said Dr. Kansagara, is that regardless of which guideline a physician follows, the publication of both last year will mean that “patients and their providers will likely have more conversations about blood pressure treatment. Both guidelines underscore the need to at least consider lower blood pressure targets in patients at high cardiovascular disease risk or in those who have had a cardiovascular disease event.” As a result of the two 2017 guidelines “I think PCPs will pay more attention to blood pressure as a modifiable risk factor.”
Dr. Casey, Dr. Whelton, Dr. Cohen, Dr. Kansagara, and Dr. Ioannidis had no disclosures.
This is part one of a two-part series. Part two will explore how the approach to diagnosis and management of hypertension spelled out in the ACC/AHA guidelines fits into the protocol-driven, data-monitored, team-delivered primary care model that has come to dominate U.S. primary care in the decade following passage of the Affordable Care Act.
