Measuring blood pressure has become more routine in the care of patients and, like other numeric data points collected within an optometric exam, ODs compare their findings against a norm. Without a standard set of guidelines for both classification of elevated blood pressure readings and also referral urgency, the information is virtually useless.
Luckily, there are several sets of internationally recognized guidelines for the diagnosis of hypertension. The problem is that they do not all agree on the “standards.” The most recently published, in fact, created quite a stir.1-4
Hypertension, based on most current standards, is defined as having a measured blood pressure of ≥140 mm Hg systolic or ≥90 mm Hg diastolic.5
Under this definition, the prevalence of hypertension in the U.S. is astounding, affecting 30.8 percent of adults age 20 or older, which in 2015 amounted to 75 million Americans.6 Prevalence increases with age, impacting 64.9 percent of those age 60 and older, and is most common among African Americans.7
These statistics have been relatively stable since the early 2000s.
However, the 2017 American College of Cardiology/American Heart Association Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure (ACC/AHC) in Adults defined hypertension as ≥2 blood pressure readings in ≥2 settings with ≥120 mm Hg systolic or ≥80 mm Hg diastolic.4,8
In conflict with other internationally recognized standards, this lower threshold for diagnosis increases the prevalence of hypertension in American adults by 26.8 percent.4,8
2017 guidelines criticized
The lowered thresholds for initiating management and treatment goals are based on lowering risk for future cardiovascular disease and the documented benefit of blood pressure reduction based on clinical trials.8
A more recent publication showed that patients had the same risk of cardiovascular disease regardless of threshold utilized, advocating an early start to therapy when indicated by the lower values.9
However, the lowered thresholds for classification and treatment have generated controversy among healthcare providers nationally and internationally with the criticism focused on the associated increased prevalence of hypertension, unnecessary treatment without perceived benefit, and subsequent cost to people and healthcare systems.1-4
On the other hand, the 2017 ACA/AHA Guidelines include 100 pages of useful points for the care of hypertensive patients, including methodologies, risk factors, etiologies, co-morbidities, and treatment strategies. Those aspects most applicable to optometry will be summarized here.8
Historically speaking, most practitioners recognize the blood pressure guidelines published by the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC), most recently updated in 2014.5
Table 1 illustrates JNC blood pressure classification and referral guidelines, with a comparison to the 2017 ACC/AHA guidelines (highlighted in gray). Generally speaking, most values are 10 mm Hg lower based on ACC/AHC.
1. Wilt TJ, Kansagara D, Qaseem A, Clinical Guidelines Committee of the American College of Physicians. Hypertension limbo: balancing benefits, harms, and patient preferences before we lower the bar on blood pressure. Ann Intern Med. 2018 Mar 6;168(5):369-370.
2. Crawford C. AAFP decides to not endorse AHA/ACC hypertension guideline: academy continues to endorse JNC8 guideline. American Academy of Family Physicians. Available at: https://www.aafp.org/news/health-of-the-public/20171212notendorseaha-acc.... Accessed 12/4/19.
3. Harmeet SR, Grover A, Hungin APS. Ambiguities in the guidelines for the management of arterial hypertension: Indian perspective with a call for global harmonization. Curr Hypertens Rep. 2017 Feb;19(2):17.
4. Khera R, Lu Y, Lu J, Saxena A, Nasir K, Jiang L, Krumholz HM.Impact of 2017 ACC/AHA guidelines on prevalence of hypertension and eligibility for antihypertensive treatment in United States and China: nationally representative cross sectional study. BMJ. 2018 Jul 11;362:k2357.
5. James PA, Oparil S, Carter BL, Cushman WC, Dennison-Himmelfarb C, Handler J, Lackland DT, LeFevre ML, MacKenzie TD, Ogedegbe O, Smith SC Jr, Svetkey LP, Taler SJ, Townsend RR, Wright JT Jr, Narva AS, Ortiz E. 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) on Detection, Evaluation, and Treatment of High Blood Pressure. JAMA. 2014 Feb 5;311(5):507-20.
6. National Center for Health Statistics. Health, United States, 2015: With Special Feature on Racial and Ethnic Health Disparities. Hyattsville, MD. National Center for Health Statistics (US). 2016. May. Report No 2016-1232.
7. CDC/NCHS, National Health and Nutrition Examination Survey (NHANES). Available at: www.cdc.gov/nchs/nhanes/index . Accessed 12/4/19.
8. 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. Circulation. 2018 Oct 23;138(17):e426-e483.
9. Flint AC, Conell C, Ren X, Banki NM, Chan SL, Rao VA, Melles RB, Bhatt DL. Effect of Systolic and Diastolic Blood Pressure on Cardiovascular Outcomes. N Engl J Med. 2019 Jul 18;381(3):243-251
10. Stavert B, McGuinness MB, Harper CA, Guymer RH, Finger RP. Cardiovascular Adverse Effects of Phenylephrine Eyedrops: A Systematic Review and Meta-analysis. JAMA Ophthalmol. 2015 Jun;133(6):647-52.
11. Venkatramani J, Mitchell P. Ocular and systemic causes of retinopathy in patients without diabetes mellitus. BMJ. 2004;328(7440):625–629.
12. Mozaffarian D, Benjamin EJ, Go AS, Arnett DK, Blaha MJ, Cushman M, de Ferranti S, Després JP, Fullerton HJ, Howard VJ, Huffman MD, Judd SE, Kissela BM, Lackland DT, Lichtman JH, Lisabeth LD, Liu S, Mackey RH, Matchar DB, McGuire DK, Mohler ER 3rd, Moy CS, Muntner P, Mussolino ME, Nasir K, Neumar RW, Nichol G, Palaniappan L, Pandey DK, Reeves MJ, Rodriguez CJ, Sorlie PD, Stein J, Towfighi A, Turan TN, Virani SS, Willey JZ, Woo D, Yeh RW, Turner MB; American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2015 update: a report from the American Heart Association. Circulation. 2015 Jan 27;131(4):e29-322.
13. Wohlfahrt P, Cífková R, Movsisyan N, Kunzová Š, Lešovský J, Homolka M, Soška V, Bauerová H, Lopez-Jimenez F, Sochor O. Threshold for diagnosing hypertension by automated office blood pressure using random sample population data. J Hypertens. 2016 Nov;34(11):2180-6.
14. Filipovský J, Seidlerová J, Kratochvíl Z, Karnosová P, Hronová M, Mayer O Jr. Automated compared to manual office blood pressure and to home blood pressure in hypertensive patient. Blood Press. 2016 Aug;25(4):228-34.