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BCGuidelines.ca - By BC Physicians, for BC Physicians

Hypertension - Detection, Diagnosis and Management

Effective Date: February 15, 2008

Summary | Flow Sheet | Patient Guide | Full Guideline in PDF

Recommendations and Topics

Scope

This guideline focuses on the detection, diagnosis and management of hypertension (HT) in non-pregnant adults (age 19 years and older). Hypertension in each category is defined by an elevation of the systolic or diastolic threshold or both.

PART 1: Detection and Diagnosis

Blood Pressure Assessment

A baseline blood pressure (BP) should be established in all adults and reassessed periodically, commensurate with age and the presence of other risk factors.1

Details of proper technique and equipment are included in Appendix A. Blood pressure monitoring should be rigorous in those patients who:

  • Have known or newly detected elevated BP
  • Have cardiovascular target organ damage *
  • Have other risk factors
  • Are receiving antihypertensive therapy

* Target organ damage includes: cerebrovascular disease, coronary heart disease (CHD), left ventricular hypertrophy (LVH), chronic kidney disease (CKD), peripheral vascular disease and hypertensive retinopathy.

Algorithm for the Detection and Diagnosis of Hypertension (see Algorithm 1)

Investigations and Risk Assessment

  • Urinalysis
  • Blood chemistry (potassium, sodium, creatinine/estimated glomerular filtration rate [eGFR])
  • Fasting blood glucose
  • Fasting total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides
  • Standard 12 lead electrocardiogram (ECG)
  • Microalbuminuria** (albumin/creatinine ratio [ACR])2,3
  • Framingham risk assessment (10-year CHD risk) (Appendix B) or UKPDS risk assessment if Type II Diabetes (DM). See Diabetes Care

** Detection of microalbuminuria as an indicator of kidney damage may be helpful when choosing a management strategy for hypertension. Currently, there is some evidence showing that angiotensin converting enzyme inhibitors (ACEI) do improve cardiovascular outcomes for patients with microalbuminuria.3

Algorithm 1: Detection and diagnosis of hypertension

(printable PDF)

Algorithm 1: Detection and diagnosis of hypertension

* Rule out exogenous factors, for example: NSAIDS, steroids, oral contraceptives, decongestants, alcohol, stimulants, salt, sleep apnea

** Assess BP for the diagnosis of hypertension:

  • Office BP assessment: Avg. BP ≥ 140/90 over 3 visits (See Appendix A for technique)
  • 1 week home/self BP measurement (if available): Avg. BP ≥ 140/90 (See Appendix C for worksheet)

*** Investigations and risk assessment:

Urinalysis; blood chemistry (potassium, sodium, creatinine/estimated glomerular filtration rate); fasting blood glucose; fasting total cholesterol; high-density lipoprotein; low-density lipoprotein; triglycerides; standard 12 lead electrocardiogram; microalbuminuria (albumin/creatinine ratio); Framingham risk assessment (10-year CHD risk) or UKPDS risk assessment if Type II Diabetes.

Note: 24-hour ambulatory blood pressure measurement may provide information on white-coat hypertension and may also be helpful in assessing patients with apparent drug resistance, hypotensive symptoms with antihypertensive medications, episodic hypertension and autonomic dysfunction.4

PART 2: Management

A flow sheet is included in this guideline (Appendix D) to help facilitate care for your hypertensive patients.

The Framingham Risk Assessment Chart (Appendix B) is designed to estimate 10-year coronary heart disease (CHD) risk in adults who do not have heart disease or diabetes. For the purpose of this guideline, CHD risk is used as a proxy for cardiovascular disease risk. The risk of stroke is approximately 25% of CHD risk.5 The risk factors included in the Framingham calculation are: gender, age, total cholesterol, HDL cholesterol, systolic blood pressure, treatment for hypertension and cigarette smoking.

The Framingham Risk Assessment Chart is a useful tool for estimating CHD risk in hypertensive patients, and may help inform your treatment decisions.

Blood Pressure Readings and the Management of Hypertension

The management of essential hypertension requires patient lifestyle management and/or therapeutic intervention to work towards the following blood pressure readings:

Table 1: Desirable blood pressure readings* † ‡

Table 1: Desirable blood pressure readings

* The benefits of initiating antihypertensive therapy when mild to moderate hypertension is first diagnosed after the age of 80 years are still uncertain.7 Treatment can be continued with caution in previously treated patients after the age of 80 years.

The risk of a systolic blood pressure in the range of 140 to 160 and/or a diastolic blood pressure in the range of 90 to 100, in the absence of target organ damage or other risk factors, is small and may not outweigh the potential harms of pharmacologic treatment in all patients.

Exercise caution in patients who have a diastolic BP close to 60, and regardless of BP, reassess the need for treatment if hypotensive symptoms exist.

Review patient at monthly intervals until BP is in the desired range for two consecutive visits. Then review every 3-6 months (as long as the patient remains stable).

At each visit:

  • Measure blood pressure
  • Reinforce benefits of a healthy lifestyle
  • Confirm that medications are taken appropriately
  • Review the patient's knowledge of their condition and their treatment
  • Establish the minimum dose of medication required to achieve the desired BP

At least annually:

  • Consider risk factors
  • Re-check co-morbidities
  • Examine for evidence of target organ damage
  • Check creatinine/ eGFR

Lifestyle Management 1,4

As a diagnosis is being established, provide adequate explanation and support to patients so that they clearly understand the nature and significance of this condition, and that they have the primary responsibility for the management of their blood pressure. Provide patients with information on available community support, such as those offered by the Heart and Stroke Foundation, including self-management courses (see Hypertension Patient Guide).

Offer and review the following lifestyle recommendations at each visit:

  • Smoking cessation: Complete cessation of smoking and avoidance of exposure to second hand smoke is recommended. For assistance to quit, refer patients to QuitNow Services at 1 877 455-2233 (toll-free in BC; available 24/7/365) and at www.quitnow.ca to obtain self-help materials.
  • Physical activity: All people should be prescribed 30-60 minutes of moderate intensity dynamic activity 4-7 days per week (dynamic activity includes: walking 3 km [2 miles] in 30 minutes once per day or walking 1.5 km [1 mile] in 15 minutes two times per day, jogging, cycling or swimming). Recommend getting a pedometer for immediate positive feedback.
  • Weight reduction: Maintenance of a healthy body weight (body mass index [BMI] 18.5-24.9 kg/m2, waist circumference < 102 cm [40"] for men and < 88 cm [35"] for women) is recommended for everyone. All overweight hypertensive individuals should be advised to lose weight. Weight loss strategies should be long-term and employ a multidisciplinary approach that includes dietary education, increased physical activity and behavioural intervention.
  • Dietary recommendations: Hypertensive individuals and normotensive individuals at increased risk of developing hypertension should consume a diet that emphasizes fruits, vegetables, low-fat dairy products, fibre, whole grains, and protein sources that are reduced in saturated fats and cholesterol (Dietary Approaches to Stop Hypertension [DASH] diet) (see Appendix E). In addition, reduced consumption of trans-fats and increased consumption of fish high in omega 3 fatty acids reduces cardiovascular risk.
  • Reduce salt intake: In addition to a well-balanced diet, a reduced dietary sodium intake of ≤ 1,500 milligrams per day (approximately 1 tsp of table salt) is recommended for individuals with hypertension. Advise patients about the "hidden" salt content of processed foods, such as lunchmeat, canned soups and pasta.
  • Alcohol consumption: Alcohol consumption should be limited to two drinks or less per day and consumption should not exceed 14 standard drinks per week for men and 9 standard drinks per week for women. A standard drink is defined as:
    • 1 can (341 mL) of 5% beer or
    • 1 glass (150 mL) of 12% wine or
    • 1.5 oz (45 mL) of 40% spirits
  • Potassium, calcium and magnesium intake: Supplementation of potassium, calcium and magnesium is not recommended for the prevention or treatment of hypertension.

Pharmacologic Treatment

An effective, individualized plan for the management of hypertension requires that benefits are considered along with potential harms. Periodically, consideration may be given to discontinuing or reducing antihypertensive medications to assess the appropriate level of pharmacologic management.

1. Indications for drug therapy in uncomplicated hypertension1

The benefits of pharmacologic treatment in people with mild hypertension (an average blood pressure between 140/90 and 160/100), and a 10-year CHD risk of less than 20% are unclear (Table 2). Use clinical judgement when recommending therapy for this patient group.

Pharmacologic treatment in addition to lifestyle modification is recommended for patients with an average blood pressure ≥ 160/100, even in the absence of other major cardiovascular risk factors.

Table 2: Benefits of blood pressure lowering with medication in patients with mild hypertension8

Table 2: Benefits of blood pressure lowering with medication in patients with mild hypertension

2. Treatment of uncomplicated hypertension

Consider monotherapy with a low-dose thiazide diuretic as first-line treatment.

If blood pressure is not adequately controlled, use combination therapy by adding one or more of the following agents:

  • Angiotensin converting enzyme inhibitor (ACEI)
  • Angiotensin II receptor blocker (ARB) if ACEI intolerant
  • Long-acting dihydropyridine calcium channel blocker (DHP-CCB)

Note:

  • Beta-blockers may no longer be a first-line treatment option (with some exceptions)9,10
  • Long-acting DHP-CCBs are a preferred second-line treatment option for patients at risk for, or with a history of, stroke
  • Alpha-blockers are not a first-line treatment option

Consideration should also be given to the addition of low-dose ASA therapy in hypertensive patients with a Framingham risk score of ≥ 20% who are between 50 and 70 years-of-age. Avoid using ASA in patients with a history of hemorrhagic stroke. Blood pressure must be well controlled.11,12

3. First-line treatment for hypertension complicated by co-morbid conditions1

It is important to control co-morbid conditions optimally when managing hypertension. Pharmacologic treatment must be chosen with even more care in these individuals. The following table lists recommended medications for consideration when individualizing antihypertensive drug therapy. See Appendix F for a list of commonly prescribed antihypertensive medications in each class.

Table 3: First-line treatment of hypertension complicated by co-morbid conditions

(printable PDF)

Table 3: First-line treatment of hypertension complicated by co-morbid conditions

4. Contraindications to antihypertensive medications

Table 4: Contraindications to antihypertensive medications

Table 4: Contraindications to antihypertensive medications

The investigation and management of secondary causes of hypertension is beyond the scope of this guideline. Please consult current medical texts for investigation and management advice, or consider referral to an appropriate specialist. For some examples of secondary causes of hypertension, refer to Appendix G.

Rationale

The following subsections include a brief overview of the literature used to generate recommendations for this guideline. The final subsection provides the methodology used for obtaining evidence and describes the types of evidence used throughout this guideline.

Hypertension (HT) remains a major public health issue in Canada. Although the diagnosis and treatment of HT appears simple, this disease remains poorly managed; for example, it is estimated that only 50% of Canadians with hypertension are aware of their diagnosis and that only 16% of Canadians with hypertension have adequate BP control.1

Combined, heart disease and stroke are the leading cause of death, accounting for one in three deaths in BC.13 Hypertension is a significant and controllable risk factor for heart disease, stroke, heart failure, renal disease and recurrent cardiovascular events.6 Hypertension is also the most common indication in Canada for visits by adults to physicians.14

The benefits of lowering blood pressure in certain settings with lifestyle changes and certain drugs have been well documented. Reductions in mortality,6,8,15 cardiovascular events,4,8,15,16 left ventricular hypertrophy,4 stroke and myocardial infarction,8,15,17 dementia,18,19 deterioration of renal function,4,15,20 renal failure20 and incidence of diabetes15 have all been associated with successful treatment of hypertension.

Evidence: Evidence was obtained through a systematic review of peer-reviewed literature (up to May, 2007) using the databases MEDLINE, PubMed, EBSCO, Ovid, and the Cochrane Collaboration's Database for Systematic Reviews. Clinical practice guidelines from other jurisdictions for the prevention and management of hypertension, diabetes, chronic kidney disease, dyslipidemia, congestive heart failure, cerebrovascular disease and overweight/obesity were also reviewed (up to May 2007). Recommendations are based on large, randomized controlled trials (RCTs) wherever possible. Lifestyle recommendations are based on large, prospective cohort trials.

References

  1. Canadian Hypertension Education Program. 2007 CHEP recommendations for the management of hypertension. 2007. www.hypertension.ca/chep/
  2. Jensen J, Feldt-Rasmussen B, Strandgaard S, et al. Arterial hypertension, microalbuminuria, and risk of ischemic heart disease. Hypertension 2000;35:898-903.
  3. Atthobari J, Asselbergs FW, Boersma C, et al. Cost-effectiveness of screening for albuminuria with subsequent fosinopril treatment to prevent cardiovascular events: A pharmacoeconomic analysis linked to the Prevention of REnal and Vascular ENdstage Disease (PREVEND) study and the Prevention of REnal and Vascular ENdstage Disease Intervention Trial (PREVEND IT). Clin Ther 2006;28(3):432-444.
  4. Chobanian AV, Bakris GL, Black HR, et al. The seventh report of the Joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure: The JNC 7 Report. JAMA 2003;289(19):2560.
  5. Wolf PA, D'Agostino RB, Belanger AJ, et al. Probability of stroke: A risk profile from the Framingham study. Stroke 1991:22(3):312-318.
  6. Whitworth JA. 2003 World Health Organization (WHO)/International Society of Hypertension (ISH) statement on management of hypertension. J Hypertens 2003;21(11):1983-1992.
  7. Elliott WJ. Management of hypertension in the very elderly patient. Hypertension 2004;44:800-804.
  8. Psaty BM, Lumley T, Furberg CD, et al. Health outcomes associated with various antihypertensive therapies used as first-line agents: A network meta-analysis. JAMA 2003;289(19):2534.
  9. Wiysonge CS, Bradley H, Mayosi BM, et al. Beta-blockers for hypertension. Cochrane Database Syst Rev 2007.
  10. National Collaborating Centre for Chronic Conditions. Hypertension: management of hypertension in adults in primary care: partial update. London: Royal College of Physicians, 2006.
  11. Baigent C. Aspirin for everyone older than 50? Against. BMJ 2005;330(7505):1442-1443.
  12. Ridker PM, Buring JE. Aspirin in the prevention of cardiovascular disease in women. N Engl J Med 2005;352(26):2752-2752.
  13. British Columbia Vital Statistics Agency. Selected vital statistics and health status indicators. One hundred and thirty-fourth Annual Report. 2005.
  14. Kaplan NM. Guidelines for the management of hypertension. Can J Cardiol 2000;16(9):1147-1152.
  15. Dahlöf B, Sever PS, Poulter NR, et al. Prevention of cardiovascular events with an antihypertensive regimen of amlodipine adding perindopril as required versus atenolol adding bendroflumethiazide as required, in the Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowering Arm (ASCOT-BPLA): a multicentre randomised controlled trial. Lancet 2005;366(9489):895-906.
  16. Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker versus diuretic: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). JAMA 2002;288(23):2981.
  17. Law MR, Wald NJ, Morris JK, et al. Value of low dose combination treatment with blood pressure lowering drugs: analysis of 354 randomised trials. BMJ 2003;326(7404):1427.
  18. Forette F, Seux M, Staessen JA, et al. Prevention of dementia in randomised double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) trial. Lancet 1998;352(9137):1347-1351.
  19. Tzourio C, Anderson C, Chapman N, et al. Effects of blood pressure lowering with perindopril and indapamide therapy on dementia and cognitive decline in patients with cerebrovascular disease. Arch Intern Med 2003;163(9):1069-1075.
  20. Casas JP, Chua W, Loukogeorgakis S, et al. Effect of inhibitors of the renin-angiotensin system and other antihypertensive drugs on renal outcomes: systematic review and meta-analysis. Lancet 2005;366(9502):2026-2033.

Resources

The BC HealthGuide Online provides detailed information on managing hypertension. Web site: www.bchealthguide.org (search word: high blood pressure)

The Heart and Stroke Foundation of Canada offers excellent materials for the control of lifestyle factors that contribute to hypertension, heart disease, stroke and kidney disease. This includes public recommendations for the control of high blood pressure, the Blood Pressure Action Plan™ (an online e-tool to help you control your blood pressure), a body mass index calculator, a risk factor calculator and specific dietary information. Web site: www.heartandstroke.ca. Telephone: 1 888 473-4636 (Toll free) (BC/Yukon division office)

The Canadian Hypertension Society has more detailed information regarding hypertension and blood pressure. Web site: www.hypertension.ca.

Dial-A-Dietitian provides accessible, quality information to the public and health information providers throughout British Columbia about nutrition. Registered dietitians provide nutrition consultation by phone. Web site: www.dialadietitian.org. Telephone 1 800 667-3438 (Toll free) or 604 732-9191 (Greater Vancouver)

American Heart Association

Web site: www.americanheart.org (search word: high blood pressure)

Mayo Clinic

Web site: www.mayoclinic.com (search word: high blood pressure)

Healthy Heart Society of BC

Web site: www.heartbc.ca/public/BP.htm

Appendices

Appendix A: Recommended Technique for Measuring Blood Pressure

Appendix B: Framingham Instruction Sheet and Risk Assessment Chart

Appendix C: Home Blood Pressure Monitoring Worksheet

Appendix D: Hypertension Care Flow Sheet

Appendix E: Dietary Approaches to Stop Hypertension (DASH)

Appendix F: Antihypertensive Drugs

Appendix G: Examples of Secondary Causes of Hypertension

Sponsors

This guideline was developed by the Guidelines and Protocols Advisory Committee, approved by the British Columbia Medical Association and adopted by the Medical Services Commission.

This guideline is based on scientific evidence current as of the effective date.

The principles of the Guidelines and Protocols Advisory Committee are to:

  • encourage appropriate responses to common medical situations
  • recommend actions that are sufficient and efficient, neither excessive nor deficient
  • permit exceptions when justified by clinical circumstances.

Contact Information
Guidelines and Protocols Advisory Committee
PO Box 9642 STN PROV GOVT
Victoria BC V8W 9P1
E-mail: hlth.guidelines@gov.bc.ca
Web site: www.BCGuidelines.ca

 

Disclaimer The Clinical Practice Guidelines (the "Guidelines") have been developed by the Guidelines and Protocols Advisory Committee on behalf of the Medical Services Commission. The Guidelines are intended to give an understanding of a clinical problem and outline one or more preferred approaches to the investigation and management of the problem. The Guidelines are not intended as a substitute for the advice or professional judgment of a health care professional, nor are they intended to be the only approach to the management of clinical problems.  We cannot respond to patients or patient advocates requesting advice on issues related to medical conditions. If you need medical advice, please contact a health care professional.