Aquifer Hypertension Guidelines Module 2018 Aquifer Hypertension Guidelines Module 1
1. Introduction. In 2013 the National Heart Lung and Blood Institute (NHLBI) asked the American College of Cardiology (ACC) and the American Heart Association (AHA) to assume responsibility for producing national guidelines regarding cardiovascular disease prevention, including the management of hypertension. In 2017, the first ACC/AHA hypertension guideline was published and immediately became the most comprehensive and up-to-date review of this crucial topic 1. The guideline document makes a large number of specific recommendations on a broad range of topics, many of which are beyond the scope of this summary. Below is a summary of the key recommendations affecting day-to-day practice. 2018 Aquifer Hypertension Guidelines Module 2
2. New Definition of Hypertension. There is ample evidence from observational studies that starting at systolic blood pressures (SBP) as low as 115 mmhg, each 10 mmhg increase in SBP leads to a consequent increase in the incidence of a wide range of negative outcomes, including acute coronary syndrome, chronic kidney disease, cerebrovascular disease, heart failure and all-cause mortality. 2 This relationship is log-linear, so the rate of the increase in bad outcomes gets increasingly high as SBP goes up. Due to this evidence, and to clinical trial research about the impact of interventions to push blood pressures lower than the traditional goal of 140/90 mmhg, the new guideline encourages physicians to change the classification of adult blood pressures as follows. BP Category SBP DBP Normal < 120 mmhg and < 80 mmhg Elevated 120-129 mmhg and < 80 mmhg Hypertension Stage 1 130-139 mmhg or 80-89 mmhg Stage 2 140 mmhg or 90 mmhg This recommendation represents a major change in clinical thinking as it lowers the decadeslong definition of hypertension from pressures above 140/90 mmhg to those above 130/80 mmhg. One estimate of the impact of this new definition is that 45.6% of the US adult population will now meet the criteria for a diagnosis of hypertension. 3 2018 Aquifer Hypertension Guidelines Module 3
3. Use of Out-of-Office Blood Pressures. It has long been known that many patients experience higher blood pressure readings in the physician s office than at home. Particularly with the new lower definition of hypertension, the phenomenon of white coat hypertension could lead to the incorrect labeling of healthy adults as having hypertension. Related to this is that blood pressure readings in clinical trials are typically as much as 5-10 mmhg lower than those in physician offices, due to the proper measurement of blood pressure after a five-minute sitting period in research studies (something very difficult to achieve in a busy medical practice). 4 Teaching Point: Out-of-office blood pressure measurement for hypertension The new guideline encourages physicians to confirm the diagnosis of hypertension and to titrate medication therapy through the use of out-of-office blood pressure readings. This can be achieved via either: Ambulatory Blood Pressure Monitoring (ABPM) - formal 24-hour blood pressure measurements using a provider-provided device, or Home Blood Pressure Monitoring (HBPM) - blood pressure readings taken by a patient at home. The meta-analysis conducted for the 2017 guideline found that clinical trials of self-measured blood pressure led to a significant, but transient (six-month) improvement in SBP compared to patients having office-based blood pressure measurements. 5 While ABPM and HBPM are increasing in frequency, many existing practices do not have well-developed systems in place to implement this particular recommendation. 2018 Aquifer Hypertension Guidelines Module 4
4. When to Initiate BP-Lowering Medications. There are a large number of lifestyle measures that have been demonstrated to lower blood pressure and decrease cardiovascular outcomes. As such, the 2017 guidelines highlight behavioral measures as the first line for managing elevated blood pressure (SBP 120-129 mmhg) and hypertension (whether initiating medications or not). Teaching Point: Recommended behavioral interventions for elevated blood pressure Weight loss for those who are overweight or obese. A heart healthy diet, such as the DASH diet or Mediterranean diet. Sodium restriction, or in those over 75 who are well nourished a trial of sodium restriction (sodium restriction may lead to decreased oral intake in older patients). Potassium supplementation, particularly from diet (eg. tomatoes, avocados, green leafy vegetables, et al.) Increased physical activity through a structured exercise program. Restriction of alcohol consumption to no more than 2 standard drinks per day for men or 1 standard drink per day for women and for all adults 65 years or older. Interventions that reduce the risk of an outcome have the largest impact when implemented in patients at higher baseline risk of that outcome (ie. larger absolute risk reduction, lower numberneeded-to-treat). Considering this phenomenon, the 2017 guidelines encourage physicians to calculate a patient s baseline risk when considering blood pressure lowering medications. Commensurate with other recent guidelines (see the Aquifer Cholesterol module), they recommend the use of the Pooled Cohort Equations to estimate a patient s 10-year risk of atherocsclerotic cardiovascular disease (ASCVD) as the principal means for assessing baseline risk. 2018 Aquifer Hypertension Guidelines Module 5
Physicians are encouraged to consider starting medication therapy for blood pressure as follows: Patient Group 10-year ASCVD risk Behavioral Interventions Medications* Stage 1 Hypertension (130-139/80--89 mmhg) Stage 1 Hypertension (130-139/80--89 mmhg) Stage 2 Hypertension (>= 140/90 mmhg) < 10% Yes No 10% Yes Yes < OR 10% Yes Yes All patients with clinical ASCVD < OR 10% Yes Yes Patients with diabetes mellitus < OR 10% Yes Yes Patient with chronic kidney disease < OR 10% Yes Yes * For all groups, the target blood pressure is 130/80 mmhg Only consider medications for such patients with stage 1 or 2 hypertension (ie. BP >= 130/80) The current guidelines dramatically increase the percentage of US adults who meet the criteria for hypertension (see New Definition of Hypertension above). However, due to the risk-based strategy for starting medications, a published analysis estimates that there will be only 1.9% more patients who require medication therapy for blood pressure (compared to prior guidelines) on the basis of these current guidelines. 3 2018 Aquifer Hypertension Guidelines Module 6
5. Choice of Medication Therapy for Hypertension. In general, the current guidelines were consistent with prior guidelines in finding that a variety of classes of blood pressure lowering medications are effective in preventing complications of hypertension. The choices of blood pressure agents are summarized in the following table: Group Medication Choices Notes General adult population Patients with Diabetes Thiazide Calcium Channel Blocker (CCB) ACE Inhibitor (ACE-I) Angiotensin Receptor Blocker (ARB) Thiazide CCB ACE-I ARB The meta-analysis conducted for the guidelines found a slight preference for thiazides (particularly chlorthalidone) as the first choice. In the absence of nephropathy, there is no preference for any starting agent. Patients with CKD ACE-I or ARB CCB and/or thiazide may be added as needed to achieve a goal of 130/80 mmhg An ACE-I or ARB is the first line in CKD. They should not be used in combination. Black Patients Thiazide CCB ACE-I ARB Older Adults Thiazide CCB ACE-I ARB Despite the meta-analysis not finding race-based differences in outcomes by choice of medication 5, this guideline recommends black patients be treated with either a thiazide or CCB as the first line. Thiazides are a reasonable first choice for most patients regardless of race. Older patients are more prone to adverse events with tight BP control, including orthostasis, falls, and kidney injury. Caution should be taken to ensure that older patients are not orthostatic before changes in medication therapy. Recommendations for tight BP control are restricted to community-dwelling seniors who are not nursing-home eligible. Patients with a limited life expectancy are unlikely to benefit from tight BP control. 2018 Aquifer Hypertension Guidelines Module 7
6. Differences from other recent guidelines. The 2017 ACC/AHA hypertension guideline represents a departure from several prominent recent guidelines. The differences can be attributed in part to the influence of more recent blood pressure trials (most notably the SPRINT trial see below 6 ) on the new guideline, but also due to differing views of the large body of evidence, which is often difficult to combine into a cohesive whole and is occasionally contradictory. The table below summarizes some of the differences in two other recent blood pressure guidelines. Guideline Agency Differences from the 2017 ACC/AHA Guideline Comments 8th Joint National BP goal of 140/90 mmhg for most Committee (JNC8) 7 adults BP goal of 150/90 mmhg for adults 60 BP goal of 140/90 mmhg for patient with diabetes More clearly articulated race-based preferences for particular classes of medications 2017 ACP*/AAFP 8 Guideline restricted to adults 60 BP goal of 150/90 mmhg for low risk adults 60 BP goal of 140/90 mmhg for high risk adults 60 BP goal of 140/90 mmhg for adults 60 with history of stroke Predated the SPRINT Trial Took a very strict evidence-based approach Often criticized for its higher SBP goal for adults 60, because this group has higher baseline ASCVD risk Took SPRINT into consideration Took a very strict evidence-based approach Panelists expressed concern over evidence of adverse events in lowering the SBP goal below 120 mmhg in the SPRINT trial (eg. syncope) * American College of Physicians American Academy of Family Physicians SPRINT Trial 6 : The 2017 ACC/AHA guideline was heavily influenced by the results of the 2015 SPRINT trial. This randomized trial studied two blood pressure goals in patients 50 years and older who had increased risk for cardiovascular disease (known prior CVD, chronic kidney disease, 10-year ASCVD risk of 15% or higher, or age > 75) and who did NOT have diabetes. In this population, those randomized to a blood pressure goal of 120/90 mmhg suffered significantly fewer cardiovascular outcomes (and all-cause mortality) than those given a goal of 140/90 mmhg. The average age was ~68, so this study provides some evidence that lower blood pressure goals may be better in older non-diabetic patients with increased CVD risk. As a cautionary note, patients in the tight control arm experienced significantly more adverse events related to antihypertensives, including hypotension, syncope, electrolyte abnormalities, and acute kidney injury. Older patients are both more likely to benefit from the positive benefits of blood pressure lowering (due to their higher baseline CVD risk) and more likely to experience these adverse events. 2018 Aquifer Hypertension Guidelines Module 8
7. Different Viewpoints In December of 2017, the American Academy of Family Physicians announced its decision to not endorse the new ACC/AHA hypertension guideline and to continue to endorse the JNC8 guideline published in 2014. 9 In the explanation of this decision the authors cited several reasons: They argued that much of the new guideline was not based on a systematic review of the literature. While it is true that many of the >100 individual recommendations were not supported by a systematic review, a new systematic review was conducted about most of the major changes in blood pressure management in the new guideline (eg. new treatment goals and choice of medications). They point out that the published systematic review looking at the optimal blood pressure treatment goals did not look at harms in addition to benefits of lower treatment goals. This is an important and valid critique. They argue that the guideline was heavily influenced by the SPRINT trial (see above) and that other trials were minimized. In fact, the chair of the new guideline panel was the principal investigator from the SPRINT trial, a situation which could influence the guideline panel s thinking. In the meta-analysis conducted in the systematic review for this new guideline, the SPRINT trial was not given extra weighting over other trials. In addition, other, more recent meta-analyses have confirmed the findings of this systematic review. They argue that the use of the ASCVD risk tool as a guide for whom to target for medication therapy is not based on randomized trials. The AAFP s decision highlights the challenges to and subtleties of interpreting clinical evidence and translating it into practice. Aquifer encourages students to remember that clinical guidelines are not intended to be treated like rigid prescriptions. Physicians must individualize their clinical decisions to the particular needs of their actual patients, using guidelines as frameworks for improving the quality of care rather than as algorithms. 2018 Aquifer Hypertension Guidelines Module 9
Contributors David Anthony, MD, MSc authored this 2018 version. Alexander Chessman, MD authored an earlier version and collaborated on this 2018 revision. Kathryn E. Callahan, MD collaborated on this 2018 version. 2018 Aquifer Hypertension Guidelines Module 10
End Notes 1 Whelton PK, Carey RM, Aronow WS, Casey DE Jr, Collins KJ, Dennison Himmelfarb C, DePalma SM, Gidding S, Jamerson KA, Jones DW, MacLaughlin EJ, Muntner P, Ovbiagele B, Smith SC Jr, Spencer CC, Stafford RS, Taler SJ, Thomas RJ, Williams KA Sr, Williamson JD, Wright JT Jr. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension. Published online November 13, 2017. 2 Lewington S, Clarke R, Qizilbash N, Peto R, Collins R; Prospective Studies Collaboration. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies.lancet. 2002 Dec 14;360(9349):1903-13. 3 Muntner P, Carey RM, Gidding S, Jones DW, et al. Potential U.S. Population Impact of the 2017 American College of Cardiology/American Heart Association High Blood Pressure Guideline. J Am Coll Cardiol. 2018 Jan 16;71(2):109-118. 4 Chobanian AV. Hypertension in 2017 - What is the right target? JAMA February 14, 2017;317(6):579-80. 5 Reboussin DM, Allen NB, Griswold ME, Guallar E, Hong Y, Lackland DT, Miller ER 3rd, Polonsky T, Thompson-Paul AM, Vupputuri S. Systematic review for the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. Published online November 13, 2017. 6 The SPRINT Research Group. A Randomized trial of intensive versus standard blood-pressure control. NEJM 2015;373:2103-2116. 7 James PA, Oparil S, Carter BL, Cushman WC, et al. 2014 evidence-based guideline for the management of high blood pressure in adults: Report from the panel members appointed to the Eighth Joint National Committee (JNC 8). JAMA 2014;311(5):507-20. 8 Qaseem A, Wilt TJ, Rich R, Humphrey LL, et al. Pharmacologic Treatment of Hypertension in Adults Aged 60 Years or Older to Higher Versus Lower Blood Pressure Targets: A Clinical Practice Guideline From the American College of Physicians and the American Academy of Family Physicians. Ann Intern Med 2017;166(6):430-37. 9 https://www.aafp.org/news/health-of-the-public/20171212notendorseahaaccgdlne.html?cmpid=em_ap_20171213. Accessed 12/20/17. 2018 Aquifer Hypertension Guidelines Module 11