The new 2017 ACC/AHA high blood pressure guidelines,¹ released November 13, 2017, has reclassified grades of hypertension for the first time as having "elevated" blood pressure with a systolic blood pressure (SBP) level of 120-129 mmHg (and with a diastolic blood pressure [DBP] level remaining <80 mmHg) and stages I versus II hypertension as being 130-139/80-89 mmHg and >140/>90 mmHg, respectively. In the old 2003 JNC 7 guidelines SBP of 120-139 mm Hg and DBP of 80-89 mm Hg were called pre-hypertension--a term no longer used. The new classification is estimated to increase the total number of American adults with elevated blood pressure to 46%, using the proposed SBP and DBP cut-points for definition of "elevated" BP, as compared to 32% of elevated BP in the adult population recommended in the 2003 JNC guidelines. However, non-drug treatment management is recommended for the majority of adults who would be newly classified as having SBP 120-129 mmHg with DBP remaining <80 mmHg.

Importantly, the new recommendations indicate a threshold for pharmacologic treatment of >130/80 mmHg, both for persons with known cardiovascular disease as well as those without. However, these new recommendations are based on 10-year atherosclerotic cardiovascular disease (ASCVD) risk derived from the ACC/AHA pooled cohort risk calculator of 10-year risk or higher. The use of the risk calculator to identify those in the primary prevention population who should be treated at the new lower 130/80 mmHg threshold is an important advancement, consistent with European risk-based treatment guidelines for hypertension, and with the use of the pooled cohort risk calculator in the 2014 ACC/AHA guideline for blood cholesterol treatment.² In the presence of BP >140/90 mmHg, even if ASCVD risk is <10%, antihypertensive treatment is indicated with a goal of reaching <130/80 mmHg. Similar to prior guidelines, a two-drug or fixed dose combination is recommended if the SBP is 20 mmHg or higher, or DBP 10 mmHg or higher from goal: thus corresponding to >150/90 mmHg as outlined in the new guidelines.

These guidelines for drug treatment initiation and goal BP levels hold for most adults, including those with diabetes (who are given a class I B-R recommendation for a 130 mmHg SBP and class I C-EO for an 80 mmHg DBP initiation and target level).¹ This is of course a reversal of recent recommendations, including those from panel members appointed by the JNC-8 as well as the European Society of Cardiology and American Diabetes Association who had all increased the treatment threshold to 140/90 mmHg in light of the failure of the ACCORD BP (Action to Control Cardiovascular Risk in Diabetes-Blood Pressure) trial to show benefit in the primary cardiovascular disease endpoint (despite showing a benefit from stroke) from the stricter 120 mmHg versus 140 mmHg SBP target.³ The current guideline committee, however, considered evidence from meta-analyses that included one study involving persons with diabetes mellitus (DM) and frequently combined with chronic kidney disease, where intensive blood pressure lowering to 133/76 mmHg versus 140/81 mmHg in the standard arm was shown to result in significant reductions in major ASCVD events of 14%, myocardial infarction 13%, and stroke 22%.⁴

These guidelines also hold for adults with metabolic syndrome, who for many, but not all, the 10-year ASCVD risk will reach 10%, warranting drug treatment at a blood pressure threshold of 130/80 mmHg, based on the multiple risk factors often present in such individuals. It should be noted, however, that because several key risk factors—notably waist circumference, glucose levels, and triglycerides—are not included in the ASCVD risk score, such calculated risk may actually be underestimated. This suggests an individualized approach to treatment even if calculated risk does not reach 10%, because the recommendations do not give specific guidance for thresholds of treatment in such persons. Furthermore, the guidelines indicate that persons with DM should use first-line classes of antihypertensive medication, including diuretics, ACE inhibitors, ARBs, and CCBs. These drug classes are useful and effective (with a class I-A recommendation); in addition, ACE inhibitors or ARBs may be considered in the presence of albuminuria (Class IIb).¹

The new guidelines also place an increased emphasis on the use of out-of-office and self-monitoring of blood pressure, i.e., home blood pressure monitoring (HBPM) and/or ambulatory blood pressure monitoring (ABPM) to confirm the diagnosis of hypertension and for titration of blood pressure medication, with a class I-A recommendation. Furthermore, a class IIa-B-NR recommendation is for screening white coat hypertension when the clinic blood pressure is in the hypertensive range but less than 160/100 mmHg, and for screening masked hypertension when the clinic blood pressure is elevated in the 120-129 mmHg SBP or 75-79 for DBP range. White coat hypertension is then diagnosed if the ABPM and/or HBPM reading are <130/80 mmHg and masked hypertension if the readings are >130/80 mmHg, respectively. In adults with white coat hypertension, periodic monitoring with either ABPM or HBPM is reasonable to detect transition to sustained hypertension, most often in the presence of elevated 10-year ASCVD risk and advanced age.⁵ For adults being treated for masked hypertension, especially in the presence of target organ damage or increased overall ASCVD risk, further screening for masked uncontrolled hypertension with ABPM may be reasonable as a class iib-C-EO recommendation.⁵ Although ABPM is the "gold standard" for detecting masked naïve and/or masked uncontrolled hypertension, the unavailability or excessive cost of ABPM may result in choosing HBPM as the second-choice procedure for diagnosing these two forms of masked hypertension. An additional option not covered in the new guidelines is office/clinic automated blood pressure measurements, which have been shown to significantly predict future ASCVD events as compared to routine office/clinic measurements.⁷ Automated office/clinic measurements have been strongly recommended in the Canadian hypertension guidelines.⁷ It is crucial, therefore, for government agencies to provide the necessary future resources for automated blood pressure monitors and ABPM.

These recommendations for ABPM or HBPM are especially relevant for those persons with diabetes, where studies have shown 30% have increased levels of masked and masked uncontrolled hypertension.⁸ Consideration should also be given for modification of the management of hypertension in specific patient groups such as those of different race/ethnicity (especially African Americans), women (including those who are pregnant), and older adults.

References

1. Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PNCA 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. J Am Coll Cardiol 2017. [Epub ahead of print]
2. Stone NJ, Robinson JG, Bairey Merz CN, et al. 2013 ACC/AHA guideline on the treatment of blood cholesterol to reduce atherosclerotic cardiovascular risk in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2014;63:2889-934.
3. ACCORD Study Group, Cushman WC, Evans GW, et al. Effects of intensive blood-pressure control in type 2 diabetes mellitus. N Engl J Med 2010;362:1575-85.
4. Xie X, Atkins E, Lv J, et al. Effects of intensive blood pressure lowering on cardiovascular and renal outcomes: updated systematic review and meta-analysis. Lancet 2016;387:435-43.
5. Franklin SS, Thijs L, Asayama K, et al. The cardiovascular risk of white-coat hypertension. J Am Coll Cardiol 2016;68:2033-43.
6. Banegas JR, Ruilope LM, de la Sierra A, et al. High prevalence of masked uncontrolled hypertension in people with treated hypertension. Eur Heart J 2014;35:3304-12.
7. Myers MG, Kaczorowski J, Paterson JM, Dolovich L, Tu K. Thresholds for diagnosing hypertension based on automated office blood pressure measurements and cardiovascular risk. Hypertension 2015;66:489-95.
8. Leitao CB, Canani LH, Kramer CK, Boza JC, Pinotti AF, Gross JL. Masked hypertension, urinary albumin excretion rate, and echocardiographic parameters in putatively normotensive type 2 diabetic patients. Diabetes Care 2007;30:1255-60.

Keywords: Blood Pressure Monitoring, Ambulatory, Antihypertensive Agents, Masked Hypertension, Blood Pressure, White Coat Hypertension, Angiotensin-Converting Enzyme Inhibitors, Metabolic Syndrome, Risk Factors, Triglycerides, Cardiovascular Diseases, Blood Pressure Monitors, Hypertension, Blood Pressure Determination, Renal Insufficiency, Chronic, Calcium Channel Blockers, Cholesterol, Stroke, Diabetes Mellitus, Myocardial Infarction, Primary Prevention

< Back to Listings