New guideline widens hypertension definition, incorporates CV risk
A newly released, long-awaited guideline published by the American Heart Association, the American College of Cardiology and nine other societies has expanded the definition of hypertension and could have tremendous implications for management of the condition, and for public health.
According to the new guideline, hypertension is now defined as systolic BP 130 mm Hg/diastolic BP 80 mm Hg, which the guideline authors propose will lead to a new diagnosis in approximately 14% more Americans, with 45.6% of U.S. adults now considered to have hypertension. The hypertension definition change was influenced by the landmark SPRINT trial, in which patients treated to a systolic BP target < 120 mm Hg had better CV outcomes compared with a target < 140 mm Hg.
The guideline lowers the threshold for hypertension from systolic BP 140 mm Hg/diastolic BP 90 mm Hg, eliminates the category of prehypertension and, for some patients, bases treatment recommendations on CVD risk.
The changes were presented in November at the AHA Scientific Sessions and published simultaneously in Hypertension and the Journal of the American College of Cardiology. Cardiology Today spoke with experts in the field immediately following the guideline release and a month later, after the community had time to digest the new guideline. Hypertension experts interviewed by Cardiology Today praised the new guideline as an accurate reflection of current science, but expressed concern about ease of implementation.
“While the news media says that now half the country is hypertensive, that’s not arbitrary at all. It’s based on very good data that look at risk,” Cardiology Today Editorial Board Member George L. Bakris, MD, professor of medicine and director of the American Society for Hypertension Comprehensive Hypertension Center, University of Chicago Medicine, and a reviewer of the new guideline, said in an interview. “It specifically has as a goal that if [a patient has] greater than 10% 10-year cardiovascular risk, you should be more aggressive with treatment. That may sound obvious, but previous guidelines assumed that, never really defined it and never put it into context. This guideline does that, and it’s a very important step forward.”
Although the new guideline emphasizes achieving BP goals of less than 130 mm Hg systolic/80 mg diastolic and identifies lifestyle changes and drugs proven to get BP under control, it is “unfortunately incredibly dense,” Cardiology Today Editorial Board Member Steven E. Nissen, MD, MACC, chairman of the Robert and Suzanne Tomsich Department of Cardiovascular Medicine at the Cleveland Clinic’s Sydell and Arnold Miller Family Heart and Vascular Institute, told Cardiology Today. “The primary people who treat hypertension are the primary care doctors, internists and family practitioners. And they’re not going to read a 200-page guideline. Making it simpler is an important goal for the medical community so that it gets implemented.”
According to the authors, the percentage of U.S. adults considered to have hypertension will rise (see Graphic), but the increase should not result in a major increase of people who will be placed on antihypertensive medications. The guideline states that in patients with stage 1 hypertension, which includes many not previously considered to have hypertension, antihypertensive medication should not be prescribed unless the patient has a previous CV event, diabetes or chronic kidney disease, or is at high 10-year risk for atherosclerotic CVD according to the ACC/AHA Pooled Cohort Equation.
The guideline changes the thresholds for elevated BP, stage 1 hypertension and stage 2 hypertension (see Table on p. 13). It eliminates the category of prehypertension and deems BP > 180 mm Hg systolic/120 mm Hg diastolic a “hypertensive crisis” that must be dealt with by a clinician immediately.
The writing committee gave a class I recommendation to a BP target of < 130 mm Hg systolic/80 mm Hg diastolic in patients with confirmed hypertension and known CVD or a 10-year risk for atherosclerotic CVD of 10% or higher, and a class IIb recommendation to that target in adults with confirmed hypertension but no additional markers for CVD risk.
The decision to make the BP target < 130 mm Hg systolic/80 mm Hg diastolic was influenced by the results of the SPRINT trial, but “there were a number of factors which led us to select the intermediate level of 130 over 80 rather than going all the way to less than 120 over 80 as a target,” writing committee vice chair Robert M. Carey, MD, MACP, FAHA, professor of medicine and dean emeritus at the University of Virginia Health System School of Medicine, said during a press conference at the AHA Scientific Sessions.
The BP target of < 130 mm Hg systolic/80 mm Hg diastolic is recommended in community-dwelling adults aged 65 years and older, but it is reasonable to consider different targets for older adults with extensive comorbidities and a limited life expectancy, writing committee chair Paul K. Whelton, MB, MD, MSc, Show Chwan Chair of Global Public Health, Tulane University School of Public Health and Tropical Medicine, Tulane University School of Medicine, said during the press conference. Whelton noted that an analysis from SPRINT showed an intensive BP target benefited patients age 75 years and older.
Keith C. Ferdinand, MD, FACC, FAHA, professor of medicine at Tulane and Cardiology Today Editorial Board Member, said the guideline has potential to improve CV health.
“The science- and evidence-based approach to this new guideline is a leap forward for clinical medicine,” Ferdinand told Cardiology Today. “The utilization of [atherosclerotic] CVD risk calculation to guide the initiation of pharmacotherapy is appropriate since it will focus attention on those patients who need medication to lower their risk.”
Lifestyle vs. medication
For patients with systolic BP 120 mm Hg to 129 mm Hg/diastolic BP < 80 mm Hg, lifestyle modifications should be encouraged, the authors wrote. Carey noted that this is also the case for systolic BP 130 mm Hg to 139 mm Hg/diastolic BP 80 mm Hg to 89 mm Hg who are not at high risk. BP-lowering medication should be used in patients with systolic BP 130 mm Hg to 139 mm Hg/diastolic BP 80 mm Hg to 89 mm Hg who are at high risk, and in all patients with systolic BP of 140 mm Hg or more or diastolic BP of 90 mm Hg or more, he said.
Recommended lifestyle modifications include weight loss; healthy diet, especially the DASH diet; reduced sodium intake, ideally < 1,500 mg per day but at least a reduction of at least 1,000 mg per day; increased potassium intake to 3,500 mg per day; physical activity of at least 90 to 150 minutes per week; and moderate alcohol intake, no more than two drinks per day for men and one drink per day for women, Carey said.
“Lifestyle should be the cornerstone” of any treatment plan, Carey stated.
Nonetheless, some patients who did not receive antihypertensive medications under previous guidelines will receive medications under the new guideline.
According to an analysis simultaneously published in Circulation and JACC by Paul Muntner, PhD, from the department of epidemiology of School of Public Health at the University of Alabama at Birmingham, and colleagues, antihypertensive medication was recommended for 34.3% of U.S. adults under the guideline written by the Seventh Joint National Committee (JNC 7) and is recommended for 36.2% of U.S. adults under the new guideline.
Role of risk assessment
In a significant departure from previous hypertension guidelines, the new guideline recommends clinicians incorporate CV risk into their treatment decisions for patients.
Risk-based decision-making is most likely to occur in adults with stage 1 hypertension, defined as systolic BP 130 mm Hg to 139 mm Hg/diastolic BP 80 mm Hg to 89 mm Hg. For these individuals, the guideline recommends starting with nonpharmacologic therapy alone for those who do not have clinical CVD or an estimated 10-year atherosclerotic CVD risk of greater than 10% according to the Pooled Cohort Equation, but combining pharmacologic and nonpharmacologic therapy for those who have one or both.
Combining pharmacologic and nonpharmacologic therapy is also recommended for patients with systolic BP 140 mm Hg/diastolic BP 90 mm Hg but no history of CVD and an estimated 10-year atherosclerotic CVD risk of less than 10%.
“The most important recommendation is to incorporate cardiovascular risk,” Wanpen Vongpatanasin, MD, FACC, FAHA, professor of internal medicine, director of the Hypertension Section, and the Norman and Audrey Kaplan Chair in Hypertension at UT Southwestern Medical Center, told Cardiology Today. “We have known that blood pressure is an important risk factor, but no one has explicitly said how do we incorporate risk into day-to-day management of hypertension. I’m glad this is part of the guideline.”
Benefits of using BP level and atherosclerotic CVD risk assessment include that “treatment is focused on patients most likely to have events, more CVD events are prevented, there is a larger absolute CVD risk reduction with treatment, there is a lower number needed to treat to prevent one CVD event, more quality-adjusted life-years are saved and the cost of care is lowered,” Carey said during the press conference.
However, Nissen questioned whether using the Pooled Cohort Equation is the best way to assess CVD risk.
“The risk calculator has been shown to be relatively inaccurate in multiple other studies,” he said. “I would have preferred if they had done something else. In addition, it hasn’t been extensively tested for blood pressure.”
Nissen also expressed concern over the guideline recommending the same BP target for almost all adults.
“I’m concerned that there are some harms such as falls associated with lowering blood pressure fairly aggressively in older people,” he said.
Optimal BP measurement
The guideline has an extensive section on how best to measure BP. The question of optimal BP measurement techniques came to the forefront after SPRINT was published, because the measurement technique used in SPRINT was very different from that typically used in clinical practice, and many experts believed it resulted in lower readings than those seen in everyday practice.
“The challenge is to get blood pressure measured accurately in clinical practice,” Vongpatanasin told Cardiology Today. “Most of the time, we are lucky to get one reading. The way SPRINT was conducted, blood pressure was measured using a standardized protocol that we often can’t afford in practice, including resting for 5 minutes, no talking and no looking at your phone. Each practice needs to think about these protocols carefully and to try to incorporate them into practice. If blood pressure is not measured carefully, it could potentially increase the risks of treatment, because there would potentially be more side effects from overtreatment.”
The guideline provides a six-step checklist for accurate measurement of BP. In general, the steps are proper preparation of the patient, proper techniques for obtaining the measurement, which measurements to take, proper documentation, averaging of at least two readings and providing the readings to the patient verbally and in writing.
“The guideline provides you a way to rule out white-coat hypertension in the office if you would simply take the time,” Bakris told Cardiology Today.
Part of the debate is whether BP measurement should be attended. In a new analysis of SPRINT presented at the AHA Scientific Sessions, the reduced risk for CV events associated with the lower systolic BP target in SPRINT occurred regardless of whether the BP measurement was attended.
BP measurements in SPRINT were an average of three readings using an automated device (907XL, Omron) after a 5-minute rest period, Karen C. Johnson, MD, MPH, FAHA, Endowed Professor of Women’s Health in the department of preventive medicine at the University of Tennessee Health Science Center and vice chair of the SPRINT steering committee, said during a press conference.
The difference in mean achieved systolic BP was consistent across BP measurement techniques. The treatment effect did not differ between patients who were always alone during measurement and those who were never alone.
“The majority of sites in SPRINT measured BP with the patient being alone at some part of the BP measuring process,” Cardiology Today Editorial Board Member Sripal Bangalore, MD, MHA, FACC, FAHA, FSCAI, associate professor of medicine, director of research of the cardiac catheterization laboratory and director of the Cardiovascular Outcomes Group in the Cardiovascular Clinical Research Center at NYU Langone Health, said in an interview. “Clinical practices should take this into consideration if they are to adopt a SPRINT-like strategy. Using the same BP target is absurd if your BP measurement technique is different since studies have clearly shown a difference in BP readings with different techniques.”
The new guideline is more than 200 pages and has 15 sections and 106 recommendations accompanied by 448 evidence tables. Even its executive summary is lengthy at 112 pages.
“It’s going to take a while to translate this to clinical practice,” Bakris said. “What may help is that the AHA has put a practice-specific version on its website that cuts out all the theory and gets right to the algorithms and a few brief sentences on why they should be followed.”
Bakris said doctors should read the guideline’s executive summary and a management algorithm near the front of the main document, which have almost everything needed for use in clinical practice.
Nissen said “the implementation piece remains to be developed and is something we have to work on. We must do a good job of educating the majority of people who treat this disorder, who are not cardiologists, on what we are trying to say.”
Bakris said success of implementation may well depend on reimbursement issues.
Those who decide on reimbursement “need to allow time for the physician to educate the patient about low-sodium diets, about getting a good sleep history, etc,” he said. “But because [doctors] are limited in time for what they’re getting paid for, it’s not happening. What really drives clinical practice is: Are there policy decisions that link payment to outcomes? If the answer is yes, doctors will follow the guideline. If the answer is no, it’s not going to happen.”
Clinicians should ensure that expanding the definition of hypertension does not have “unintended consequences,” Bangalore told Cardiology Today.
“The positive aspects are that starting early might be beneficial to reduce the risk of events, but let’s not forget that branding somebody with a disease condition may actually worsen it,” he said. “At the end of the day, you have to individualize treatment.”
Nonetheless, Ferdinand said, the new guidance represents a positive step toward reclaiming the gains made in prevention of CVD and mortality from it, which have slipped in recent years due to increasing prevalence of uncontrolled risk factors, diabetes and obesity.
“It is indeed the control of risk factors, including hyperlipidemia and hypertension, which have been the primary reasons for the decline in CVD mortality that has been seen in the United States,” Ferdinand said. “If we don’t control hypertension, then we may actually see a reversal of these gains in heart disease and stroke.” – by Erik Swain
- Johnson KC, et al. LBS.03. Latest Insights into Hypertension Management. Presented at: American Heart Association Scientific Sessions; Nov. 11-15, 2017; Anaheim, California.
- Muntner P, et al. Circulation. 2017;doi:10.1161/CIRCULATIONAHA.117.032582.
- Muntner P, et al. J Am Coll Cardiol. 2017;doi: 10.1016/j.jacc.2017.10.073.
- The SPRINT Research Group. N Engl J Med. 2015;doi:10.1056/NEJMoa1511939.
- Whelton PK, et al. Hypertension. 2017;doi:10.1161/HYP.0000000000000065.
- Whelton PK, et al. J Am Coll Cardiol. 2017;doi:10.1016/j.jacc.2017.11.006.
- For more information:
- George L. Bakris, MD, can be reached at firstname.lastname@example.org.
- Sripal Bangalore, MD, MHA, FACC, FAHA, FSCAI, can be reached at email@example.com.
- Robert M. Carey, MD, MACP, FAHA, can be reached at firstname.lastname@example.org.
- Keith C. Ferdinand, MD, FACC, FAHA, can be reached at email@example.com.
- Steven E. Nissen, MD, MACC, can be reached at firstname.lastname@example.org.
- Wanpen Vongpatanasin, MD, FACC, FAHA, can be reached at email@example.com.
- Paul K. Whelton, MB, MD, MSc, can be reached at firstname.lastname@example.org.
Disclosures: Bakris, Bangalore, Carey, Johnson, Muntner, Nissen, Vongpatanasin and Whelton report no relevant financial disclosures. Ferdinand reports he is a consultant for Amgen, Boehringer Ingelheim, Novartis, Quantum Genomics and Sanofi.