Hypertension - Diagnosis and Management

Effective Date: March 1, 2015
Revised Date: June 22, 2016

Recommendations and Topics

Scope

This guideline provides recommendations on how to diagnose and manage hypertension (HTN) in adults aged ≥ 19 years. Outside the scope of this guideline is the management of secondary causes of HTN,* accelerated HTN, acute HTN in emergency settings, and in pregnant adults. The amount of randomized controlled trials informing care of the elderly with raised blood pressure is limited.

For an algorithm of this guideline, refer to Appendix A: Diagnosis and Management of Hypertension Algorithm.

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Key Recommendations ¥,1

  • 140/90 or lower is the desirable blood pressure reading for an adult with no co-morbid conditions, diabetes, chronic kidney disease or other target organ damage.2 [Level 2, amended 2015]
  • When taking office blood pressure readings, the use of an automated office blood pressure measuring electronic device is recommended.3 [Level 2, new 2015]
  • Consider 24-hour ambulatory blood pressure monitoring or home blood pressure monitoring to confirm a hypertension diagnosis.4 [Level 1, new 2015]  
  • Instigate pharmaceutical management in context of the patient’s overall cardiovascular risk and not solely on their blood pressure.5 [Level 1, amended 2015]
  • Lifestyle management is recommended for those with mild hypertension (average blood pressure = 140 – 159/90 – 99), low-risk for cardiovascular disease and no co-morbidities.6 [Level 1, 2008]

Definition

An elevated blood pressure (BP) is defined as a systolic blood pressure (SBP) > 140 mm Hg or diastolic blood pressure (DBP) > 90 mm Hg or both.

Detection

In patients aged ≥ 45 years, BP should be recorded at least once every 5 years. This recording should be the average of several measurements.

Ensure standardized technique (e.g., patient in a seated position, selecting the arm with the higher BP) and equipment are being used (refer to Appendix B: Recommended Methods and Techniques for Measuring Blood Pressure). When possible, use an automated office BP measuring electronic device, as an alternative to manual office BP technique.3 Using automated office BP reduces errors due to improper technique, avoiding an overestimation of BP values (white-coat HTN) or underestimation of BP values (masked HTN).

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Diagnosis 7 - 9

Assessment of Elevated Blood Pressure

If average BP is elevated again, proceed to investigations and work-up to assess target organ damage and cardiovascular disease (CVD) risk. Select which arm to use by measuring BP in both arms with the patient in a seated position. Measure BP three more times using the arm with the higher reading, then discard the 1st reading and average the latter two.

Figure 1. Diagnosis of hypertension algorithm

Investigations and work-up includes:

  1. Medical history - ask about risk factors and rule out any exogenous factors

Risk Factors

  • Modifiable: smoking; physical activity levels/sedentary lifestyle; poor diet; body composition (e.g., body weight, body mass index, waist circumference); poor sleep; psychological factors (e.g., stress levels).
  • Non-modifiable: age; family history; ethnicity (e.g., African, Caribbean, South Asian (East Indian, Pakistani, Bangladeshi,Sri Lankan) origin).

Exogenous factors

  • White-coat HTN (~20% of patients with high manual office BP readings); prescription drugs (e.g., nonsteriodal anti-inflammatory drugs (NSAIDs), steroids, oral contraceptives, decongestants); and others (e.g., alcohol, stimulants, sodium).
  1. Physical examination - fundoscopy, central and peripheral cardiovascular examination, and abdominal examination
  2. Urinalysis - albumin to creatinine ratio (ACR), hematuria
  3. Test for blood chemistry - potassium, sodium, creatinine/estimated glomerular filtration rate (eGFR)
  4. Test for type 2 diabetes - fasting blood glucose OR hemoglobin A1c level
  5. Test for lipids - full lipid profile
  6. Electrocardiogram (ECG) standard 12-lead
  7. CVD risk assessment - Framingham Risk Score or www.bestsciencemedicine.com/chd/calc2.html. Refer to BCGuidelines.ca: Cardiovascular Disease – Primary Prevention.

Consider 24-hour ambulatory or home BP monitoring for appropriate patients (e.g., suspected white-coat HTN, unusual fluctuating office-based BP readings).4

Table 1. Ranking of preferred methods for measuring blood pressure by accuracy and accesibility3, 7, 10, 11

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Assessment of Hypertension

If ambulatory or home BP monitoring was not conducted, measure office BP again. A HTN diagnosis may be confirmed at this visit. If a HTN diagnosis cannot be confirmed or ruled out, consider ambulatory or home BP monitoring. Further office visits may be required.

Indications for Consultation with a Specialist

Indications for consultation with a specialist include:

  • Hypertensive emergency – DBP > 130 or BP > 180/110 with signs/symptoms;*
  • Sudden onset in the elderly;
  • Abnormal nocturnal BP differences12 – an extreme nocturnal BP dip (>20%), non/small nocturnal BP dip (<10%), or an increase in nocturnal BP are at risk for CVD;
  • Signs or symptoms suggesting of secondary causes of the HTN; and
  • Resistant HTN – BP still difficult to control after treating with 3 antihypertensive medications.

Management

Once a diagnosis has been confirmed, conduct a patient-specific discussion to decide upon desirable BP readings and an individualized treatment plan. This discussion should consider any benefits and potential harms.

Desirable Blood Pressure Readings

140/90 or lower is the desirable blood pressure reading for an adult with no-comorbid conditions, diabetes, chronic kidney disease or other target organ damage.2 However, an individual patient’s desirable BP is influenced by their age, presence of target organ damage, CVD risk level and/or the presence of other CVD risk factors (refer to BCGuidelines.ca: Cardiovascular Disease – Primary Prevention).

This guideline uses the term ‘desirable BP’ instead of ‘targets’ to encourage clinical judgement when dealing with an individual patient. The suggested desirable BP readings of 140/90 is provided as guidance only, since recommending a uniform threshold for all patients or even patient groups is not optimal. Also, the term ‘targets’ is not used because the treat-to-target approach is not recommended.

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Controversies in Care: Blood Pressure Readings in the Diabetes Population

This guideline recommends a desirable BP reading of 140/90 for the diabetes population. There is an acknowledgement that this does not align with the Canadian Hypertension Education Program’s7 or the Canadian Diabetes Association’s12 recommendation of a 130/80 target; but it does align with the Eighth Joint National Committee’s9 and National Institute for Health and Care Excellence’s8 guidance. The target of 130/80 is not supported by any randomized controlled trials, and therefore is mostly consensus based. However, there is no evidence to completely discard the 130/80 either. A desirable BP of 140/90 is based on a recent large clinical trial2 that found no significant difference between a target of 140/90 versus 120/80, thus a 130/80 would unlikely be beneficial versus 140/90. Future trials are needed to bring clarity to this issue.

Lifestyle Management

Recommend lifestyle management for patients with mild HTN (average BP = 140 – 159/90 – 99), low-risk for CVD and no co-morbidities (refer to Table 3 for list of co-morbidities).6

The benefits of pharmacologic treatment in the mild HTN group is unknown, and may not outweigh the potential harms (e.g., increased risk of falls).14 In a recent systematic review, pharmaceutical treatment within this patient group did not reduce total mortality, total CV events, coronary heart disease or stroke, when compared to a placebo treatment.14 Whereas, the benefits of lifestyle management (e.g., smoking cessation, increasing physical activity, obtaining or maintaining a healthy body composition, eating a well-balanced diet, and monitoring salt intake) with this patient group has been documented (refer to Table 2). For more information, refer to BCGuidelines.ca: Lifestyle & Self-Management Supplement (In Progress).

Table 2. Impact of health behaviours on blood pressure7, 8

Table 2, Impact of health behaviours on blood pressure
 

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Pharmaceutical Management7 

Instigate pharmaceutical management in context of the patient’s overall CVD risk (e.g., not solely based on a patient’s BP) and in conjunction with lifestyle management.5 Pharmacologic management may be considered if:

  1. Average BP is > 140/90 and with target organ damage or CVD risk >20%;
  2. Average BP is > 140/90 with 1+ co-morbidities (refer to Table 3 for co-morbidities list);
  3. Average BP is ≥ 160/100; or
  4. Desirable BP is not reached with lifestyle management.

Treatment of Hypertension without Specific Indications

In general, antihypertensive medications are equally effective in lowering BP. When prescribing one, take into account cost of the drug, any side-effects and any potential contraindications. For a list of commonly prescribed antihypertensive medications in each class, refer to Appendix D: Commonly Used Antihypertensive Drugs.

Without specific indications, consider monotherapy with one of the following first-line drugs:

  • Thiazide diuretic;
  • Long-acting calcium channel blocker (CCB);
  • Angiotensin converting enzyme inhibitor (ACE-I; in non-black patients); or
  • Angiotensin II receptor blocker (ARB).

Among these, thiazide diuretics are the least costly agents. Although hydrochlorothiazide (12.5 to 25 mg daily) is the more commonly prescribed thiazide diuretic for monotherapy, outcome studies15, 16 suggested that it may be inferior to chlorthalidone (12.5 to 25 mg daily) in reducing CV events (e.g., non-fatal myocardial infarction, stroke, or death).17 However, chlorthalidone poses a slightly higher risk of hypokalemia (7-8%) than hydrochlorothiazide, even at low doses.18

Note that alpha-blockers are no longer considered to be a first-line option. Beta-blockers are not a preferred first-line drug but may be used for patients aged < 60 years old and those with specific indications (e.g., stable angina).

If desirable BP is not achieved with standard-dose monotherapy, use combination therapy by adding one or more of the first-line drugs. Combination of ACE-I and ARB is not recommended, and caution with combining a non-dihydropyridine CCB (i.e., verapamil or diltiazem) and a beta-blocker.

Treatment of Hypertension with Specific Indications

Selecting an antihypertensive drug for a patient with 1+ co-morbidities may require a specific first-line drug. Refer to Table 3 for recommended first-line and second-line treatments.

Table 3. Pharmacologic treatment recommendations of hypertension complicated by co-morbidity7

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Follow-up to Treatment

Two weeks after instigating antihypertensive medications, follow-up with an eGFR to monitor kidney function. Then, follow-up with the patient at monthly intervals until BP is in a desired range for two consecutive visits. Review every 3 - 6 months (as long as the patient remains stable). Establish the minimum dose of medication required to achieve the desired BP. Periodically, consider discontinuing or reducing antihypertensive medications to assess the appropriate level of pharmacologic management. Monitor kidney function whenever medications are changed (e.g., dose adjustments).

Ongoing Care

Implement self-management strategies to assist the patient in managing their BP. At least annually, review the patient’s risk factors, examine for evidence of target organ damage, and check eGFR and ACR.

Resources

References

  1. OCEBM Levels of Evidence Working Group. The Oxford 2011 Levels of Evidence. Oxford Centre for Evidence-Based Medicine. Available at: www.cebm.net
  2. Cushman WC, Evans GW, Byington RP, et al. ACCORD Study Group. Effects of intensive blood-pressure control in type 2 diabetes mellitus. N Engl J Med. 2010;362(17):507-515.
  3. Myers MG, Kaczorowski J, Dawes M, et al. Automated office blood pressure measurement in primary care. Can Fam Physician. 2014;60:127-32.
  4. Hodgkinson J, Mant J, Martin U, et al. Relative effectiveness of clinic and home blood pressure monitoring compared with ambulatory blood pressure monitoring in diagnosis of hypertension: Systematic review. BMJ (Clinical Research Ed.) 2011;342, d3621.
  5. The Blood Pressure Lowering Treatment Trialists’ Collaboration. Blood pressure-lowering treatment based on cardiovascular risk: A meta-analysis of individual patient data. Lancet. 2014;384:591-98.
  6. Dickinson HO, Mason JM, Nicolson DJ, et al. Lifestyle interventions to reduce raised blood pressure: A systematic review of randomized controlled trials. J Hypertens. 2006;24(2),215–233.
  7. Dasgupta K, Quinn RR, Zarnke KB, et al. The 2014 Canadian Hypertension Education Program recommendations for blood pressure measurement, diagnosis, assessment of risk, prevention and treatment of hypertension. Can J Cardiol. 2014;30:485-501.
  8. National Institute for Health and Care Excellence. Hypertension: The clinical management of primary hypertension in adults (Clinical Guidance 127). 2011. London: National Institute for Health and Care Excellence.
  9. James PA, Oparil S, Carter BL, 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. doi:10.1001/jama.2013.284427.
  10. Myers MG, Godwin M, Dawes M, et al. Measurement of blood pressure in the office: Recognizing the problem and proposing the solution. Hypertension. 2010;55:195-200.
  11. Kaczorowski J, Dawes M, Gelfer M. Measurement of blood pressure: New developments and challenges. BCMJ. 2012;54(8):399-403.
  12. Fagard RH. Dipping pattern of nocturnal blood pressure in patients with hypertension. Expert Rev Cardiovasc Ther. 2009;7(6):599-605.
  13. Canadian Diabetes Association Clinical Practice Guidelines Expert Committee, Gilbert R, Rabi D, LaRochelle P, et al. Treatment of hypertension. Can J Diabetes. 2013;37 Suppl 1: S117-8.
  14. Diao D, Wright JM, Cundiff DK, et al. Pharmacotherapy for mild hypertension. Cochrane Database Syst Rev. 2012;8:CD006742.
  15. Dorsch MP, Gillespie BW, Erickson SR, et al. Chlorthalidone reduces cardiovascular events compared with hydrochlorothiazide: A retrospective cohort analysis. Hypertension. 2011; 57(4):689–94.
  16. Roush GC, Holford TR, Guddati AK. Chlorthalidone compared with hydrochlorothiazide in reducing cardiovascular events: Systematic review and network meta-analyses. Hypertension.  2012;59(6):1110–17.
  17. Messerli FH, Makani H, Benjo A, et al. Antihypertensive efficacy of hydrochlorothiazide as evaluated by ambulatory blood pressure monitoring: A meta-analysis of randomized trials. JACC. 2011;57(5):590-300.
  18. The ALLHAT Officers and Coordinators for the ALLHAT Collaborative Research Group. Major outcomes in high-risk hypertensive patients randomized to angiotensin-converting enzyme inhibitor or calcium channel blocker vs diuretic: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). JAMA. 2002;288(23):2981-2196.

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Resources

  • RACE - Rapid Access to Consultative Expertise program, a telephone advice line from a selection of specialty services for general practitioners.
  • CHEP - Canadian Hypertension Education Program, www.hypertension.ca/en/chep
  • BHS - British Hypertension Society, www.bhsoc.org/
  • BC Guidelines - www.BCGuidelines.ca
    • Cardiovascular Disease – Primary Prevention
    • Lifestyle & Self-Management Supplement (In Progress)

Appendices

Associated Documents

The following documents accompany this guideline:

 

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This guideline is based on scientific evidence current as of the Effective Date.

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.

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 problem. 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.

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