Summary There seems to be a new guideline coming out soon, read some comments here. Otherwise, read below a summary of the 2014 Guidelines with added comments and explanations.

Definition

HTN is defined as a persistent elevation of office blood pressure (BP) ≥ 140/90 mmHg. Measured on three separate occasions within four weeks (2011 Guidelines state 8 weeks), unless the BP is ≥ 180/110. The blood pressure should also be recorded in the correct manner. The optimal BP is a value < 130/85 mmHg. Patients with BP ≥ 160/110mmHg should begin drug therapy and lifestyle modification. Patients with Grade 1 hypertension should begin with lifestyle modification for three to six months unless they are stratified as being “high risk”. High-risk patients are those with three or more major risk factors, diabetes, target-organ damage, or complications of hypertension (see table below).

Stage	Systolic BP mmHg	Diastolic BP mmHg
Normal	< 120	<80
Optimal	120 – 129	80 – 84
High Normal	130 – 139	85 – 89
Grade 1	140 – 159	90 – 99
Grade 2	160 – 179	100 – 109
Grade 3	≥ 180	≥ 110
Isolated systolic	≥ 140	< 90

The blood pressure measurement should also be measured correctly. There are a few things one should keep in mind while performing the blood pressure reading. The table below describes some of the most common, but there are more!

Recommendation for BP Measurement
- Patient sits for 3-5mins before BP measurement - SBP is measured by palpation first, in order to avoid missing the auscultatory gap - Take two readings, 2 minutes apart. If the next reading is more than 5mmHg different from the previous one then repeat. - Measure both arms’ BP - Patient should be seated, with arm supported at heart level - Patient should have NOT smoked, taken caffeine in the previous 30minutes - The correct cuff size - Take Korotkoff I and V as SBP and DBP

Recommendation for BP Measurement

- Patient sits for 3-5mins before BP measurement
- SBP is measured by palpation first, in order to avoid missing the auscultatory gap
- Take two readings, 2 minutes apart. If the next reading is more than 5mmHg different from the previous one then repeat.
- Measure both arms’ BP
- Patient should be seated, with arm supported at heart level
- Patient should have NOT
smoked, taken caffeine in the previous 30minutes
- The correct cuff size
- Take Korotkoff I and V as SBP and DBP

Types & Terms

Primary Hypertension (95%): AKA Essential hypertension, cause of this type of hypertension is not known.
Secondary Hypertension (5%): The blood pressure is a result of another medical problem or medication.
Malignant hypertension: When the blood pressure is severely elevated and it causes organ damage. Diastolic is usually higher than 140.
Gestational Hypertension
White-coat hypertension: There are higher readings in the office compared to outside the office
Masked Hypertension: There is normal BP readings in the office but higher BP readings outside the office. Usually will have features of target-organ damage.
Resistant Hypertension: When more than three different anti-hypertensives are prescribed and the blood pressure is still elevated.

Assessement

You need to assess the following three things (major risk factors, target organ damage, and complications) for each patient. These findings will help you identify the patients that are “high risk” patients, and these patients will also need treatment.

Major Risk Factors	Target Organ Damage (TOD)	Complications
-level of systolic and diastolic BP -smoking -dyslipidemia (Total Cholesterol > 5.1 mmol/L OR LDL > 3mmol/L OR HDL in MEN < 1 and WOMEN < 1.2mmol/L -Diabetes Mellitus -Men age > 55 -Women age > 65 -Family history of early onset cardiovascular disease (Men Aged < 55, Women Aged < 65) -Waist Circumference (Men ≥ 102cm, Women ≥ 88cm). However South Asians and Chinese waist circumference in men > 90cm and in women > 80cm	-Left Ventricular Hypertrophy (based on ECG as Sokolow-Lyons > 35mm, R in aVL > 11mm, Cornel > 2440 mm/ms) -MICROalbuminuria (Albumin:Creatinine ratio of 3 – 30mg/mmol from spot urine in the mornings and an eGFR > 60ml/min)	-Stroke/TIA -Advanced Retinopathy (hemorrhages, exudates OR papilledema) -Coronary Heart Disease -Heart Failure -Chronic Kidney Disease (MACROalbuminuria > 30mg/mmol OR eGFR < 60ml/min)

Routine Investigations

Height, Weight, BMI: The ideal BMI is < 25 kg/m2 [Done at every visit]
Waist Circumference: As stated above, MEN should be < 102cm and women < 88cm [Done at every visit]
Blood Tests [Done at first visit, then yearly]
1. Fasting Glucose: Should consider HbA1c or GTT if impaired fasting glucose (6.1 – 7.1mmol/L)
2. Cholesterol: If the total cholesterol is > 5.1, then do a fasting lipogram
3. Creatinine: To calculate eGFR / Renal function
4. Electrolytes: Consider a low K+ as a sign of primary aldosteronism or as an effect of diuretics.
5. Uric acid: High uric acids is a relative contra-indication to diuretics
ECG: Should be done if indicated and if there is availability. Assess for LVH. [Done at first visit and yearly]
Urine dipstick: If there is any abnormality, should be sent for microscopy and protein estimation [Done at first visit, then yearly]

BP Targets

The universal target for antihypertensive treatment is BP < 140/90 mmHg regardless of the cardiovascular risk or any other co-morbidities. However, as an exception, elderly patients above 80 years old should have a target goal of 140 – 150 mmHg.
The other co-morbidities should also be treated: hyperlipidemia and diabetes
Aspirin is not routinely prescribed, especially if the blood pressure is not controlled. It is mainly used for secondary prevention of cardiovascular disease.
In the 2011 guidelines, all patients needed a target goal of < 140/90mmHg, except patients who were at high risk (diabetes mellitus, renal disease, congestive heart failure) who would benefit from a blood pressure of < 130/80 mmHg.

Management

Non-pharmacological

Weight: Advice the patient to loose weight to a BMI of 18.5 – 24.9 kg/m2
Diet: Decrease saturated fats, total fats and increase fruits and vegetables
Dietary Na+ (Salt): < 100 mmol or 6g NaCl/day (a teaspoon = 6g of salt)
Physical Activity: Brisk walking for 30mins per day most days
Moderation of alcohol: No more than two drinks per day for men, less than 1 drink for women. A standard drink (approximately 10 g of ethanol) is equivalent to 25 ml of liqueur/spirits, 125 ml of wine, 340 ml of beer, or 60 ml of sherry.
Tobacco: Complete cessation (including snuff)

Pharmacological

NB: You can start with either of the medications described below, but always consider the patient profile, agent/drug profile, and/or any indications.

Patients ALWAYS need lifestyle modification
In most uncomplicated primary hypertension, you can initiate them on a diuretic (thiazide), ACE Inhibitor or Angiotensin Receptor Blocker, and/or Calcium Channel Blocker to be used as monotherapy or as in combination. It is important to think of these agents’ side effects, patient profile, contraindications, complications, and any target organ damage incurred by these patients.
If the patient has an initial BP ≥ 160/110 (Grade 2), if possible, they may be initiated on combination therapy.
After diagnosing hypertension:
1. If BP is GRADE 1 with < 3 major risk factors, no diabetes, no target organ damage or complications
  1. Treatment: Lifestyle modification for 3 – 6 months. If the goal is NOT achieved after the 3 – 6 months then initiate monotherapy on the following visit and review in 4-6 weeks. If the BP is not controlled yet, then treat it as GRADE 2.
2. If BP is GRADE 1 with ≥ 3 major risk factors, diabetes, target organ damage, or complications
  1. Treatment: Lifestyle modification AND start monotherapy. Review the patient in 4-6 weeks. If BP is not controlled yet then treat it as GRADE 2.
3. If BP is GRADE 2
  1. Treatment: Lifestyle modifications and start a two-drug therapy, review in 4-6 weeks. If the BP is still not controlled then you may add a third drug OR optimize the current agent’s dosages.
4. If BP is GRADE 3, then treat it as SEVERE HYPERTENSION.
  1. Asymptomatic Severe Hypertension
    1. These patients have severe hypertension, but they are asymptomatic without evidence of target organ damage or complications
    2. Keep these patients rested and repeat blood pressure measurements after 1 hour
    3. If it is still elevated commence oral therapy using two first-line drugs
    4. Follow up within a week OR earlier
    5. Early referral is adviced if the blood pressure is not controlled withoin 2-4 weeks
  2. Hypertensive Urgency
    1. Usually present as an symptomatic patient with headache, shortness of breath and oedema
    2. There is NO immediate life threatening neurological, eye, cardiac or renal complications such as in hypertensive emergencies
    3. Need to treat them at the hospital
    4. Commence treatment with two oral agents and aim to lower the diastolic BP to 100mg slowly over 48 to 72 hours. Use either long acting calcium channel blocker, ACEI at low doses, B-blockers or diuretics.

Hypertensive Emergency
1. It is an severe ACUTE elevation of blood pressures associated with ACUTE and ongoing organ damage to the brain, eyes (grade 3 or 4 retinopathy), heart, kidneys or vascular system.
2. Preferrably should be treated in ICU, if not possible treat them hin a ward where they can be closely monitored
3. Blood pressure should be treated and lowered from minutes to hours.
4. Intravenous anti-hypertensive have become the standard of care
  1. Labetalol, Nitroprusside, Nitroglycerin
  2. Reduced the blood pressure only 25% over 24 hours
  3. Begin oral therapy once blood pressures are controlled
5. NB: Caution with lowering blood pressure in patients with ischaemic strokes since this may lead to the extension of the ischaemic penumbra

Notes: Loop diuretics such as furosemide should not be used because of their short duration of hypotensive activity (about 6 hours), unless there is evidence of chronic kidney disease (CKD) with an estimated glomerular filtration rate (GFR) <45 ml/min.

The BP Triangle

The triangle below shows how you can initiate the patient’s treatment. You may select either an ACEI/ARB OR Thiazide OR a CCB. You will then need to remember some common side effects.

For instance, you initiate the patient on a Thiazide, then you realize on a review that the treatment is not working. You can pick either an ACEI/ARB or CCB.

If the treatment is still not successful, then you can select the remaining agent in the triangle. Then you can consider optimizing the agent’s doses (by increasing the dose).

If there is still an issue with the patient’s blood pressure, then you may consider adding a 4th agent. Before jumping to a B-Blocker (Carvedilol), you may consider using an MRA(Spironolactone).

You need to select an agent that will benefit the patient. For instance, patients with Diabetes Mellitus benefit from ACE Inhibitors. B-Blockers are contra-indicated in patients with Diabetes. Although it is stated that some agents have “poor response in Africans”, it does not mean that they should not be used. It just means that these agents should ideally not be used alone or as first-line treatment.

For more information, read our article called, “Common drugs used for hypertension.“

Disclaimer: The information written above is mostly adapted from the South African Hypertension Practice Guidelines 2014 (YK Seedat, BL Rayner, Yosuf Veriava) and full credit is given to their authors. Where possible, information from the South African Hypertension Guidelines 2011 (Y K Seedat, B L Rayner) was also used and from the EML Guidelines.

References and Further Reading 1. South African Hypertension Guideline 2011 - KZN health (no date). Available at: https://tinyurl.com/2s45xdcx (Accessed: November 23, 2022).
2. Guidelines (no date) Southern African Hypertension Society. Available at: https://tinyurl.com/y89znt8p (Accessed: November 23, 2022).

Published on 11 July 2022

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