Hypertension control has significant benefit for patients.

Detect and treat co-existent risk factors.

Assess cardiovascular risk.

Lifestyle modification and patient education is essential for all patients.

Medicine treatment is needed for SBP >140 mmHg and DBP > 90 mmHg. See medicine treatment choices below.

Immediate medicine treatment is needed for DBP > 110 mmHg and/or SBP >180 mmHg.

Patient evaluation for risk stratification [target organ damage (TOD) and clinical cardiovascular disease (CCD) and co-morbidity]

Thorough focused history and clinical examination is complemented by investigations.

Major risk factors for CVD:

»      diabetes mellitus,

»      hypertension,

»      obesity,

»      smoking,

»      dyslipidaemia, or

» family history of primary hypertension or premature cardiovascular disease in men <55 years and in women <65 years.

Target organ damage (TOD):

»             left ventricular hypertrophy, »           microalbuminuria, or »       elevated creatinine level.

Associated clinical condition (ACC):

»     ischaemic heart disease (angina or prior myocardial infarction),

»      heart failure,

»      stroke or transient ischaemic attack,

»      chronic kidney disease,

»      retinopathy,

»     peripheral arterial disease.

 Investigations

If overweight, record body weight and waist circumference at each visit when BP is measured. Central obesity is defined as waist circumference:

»                 102 cm in men, and

»        88 cm in women.

Do urine test strip analysis for protein, blood and glucose at presentation.

»      If normal, repeat urine test strip every 6 months.

»     If abnormal, do spot urine albumin:creatinine ratio. Repeat yearly.

»      If haematuria > 1+, investigate further.

»     If glycosuria, exclude diabetes mellitus.

»      If known diabetic, HbA_1c and fasting glucose.

»      Random total cholesterol.

»     If diabetic, do spot urine albumin creatinine ratio. Repeat yearly.

         >     normal: <3 mg/mmol

         >     microalbuminuria: 3–30 mg/mmol

         >     macroalbuminuria: >30 mg/mmol or overt nephropathy.

» Perform a resting ECG to exclude left ventricular hypertrophy or ischaemia.

»      Assess renal function (serum creatinine and eGFR).

Goals of treatment

Aim for SBP <140 mmHg and DBP <90 mmHg.

GENERAL MEASURES

Lifestyle modification

All persons with hypertension should be encouraged to make the following lifestyle changes as appropriate.

»     Smoking cessation.

» Maintain ideal weight, i.e. BMI <25 kg/m². Weight reduction in the overweight patient.

» Salt restriction with increased potassium intake from fresh fruits and vegetables (e.g. remove the salt from the table, gradually reduce added salt in food preparation and avoid processed foods).

» Reduce alcohol intake to no more than 2 standard drinks per day for males and 1 for females.

» Follow a prudent eating plan i.e. low fat, high fibre and unrefined carbohydrates, with adequate fresh fruit and vegetables.

» Regular moderate aerobic exercise, e.g. 30 minutes brisk walking at least 3 times a week.

MEDICINE TREATMENT

Initial drug choice in patients qualifying for treatment is dependent on the presence of compelling indications.

Advise patient to take medication regularly, including on the day of the clinic visit.

 Note:

Check adherence to antihypertensive therapy.

Monitor patients monthly and adjust therapy if necessary until the BP is controlled.

After target BP is achieved, patients can be seen at 3–6 monthly intervals.

Medicine treatment choices without compelling indications

Low risk: BP <160/100 mmHg, no risk factors, Target organ damage (TOD) or Associated clinical condition (ACC).

»    Lifestyle modification for 3–6 months.

»     Start antihypertensive therapy if target BP not achieved.

Moderate risk: BP <180/110 mmHg, 1–2 risk factors, no diabetes, TOD and/or ACC.

»    Lifestyle modification for 3–6 months.

»     Start antihypertensive therapy if target BP not achieved.

High or very high risk: BP >140/90 mmHg with 3 or more risk factors, diabetes, TOD and/or ACC.

Lifestyle modification with immediate antihypertensive therapy.

Low dose thiazide diuretic e.g.:

• Hydrochlorothiazide, oral, 12.5 mg daily.

If target blood pressure is not reached after one month despite adequate adherence, add one of the following: ACE inhibitor or calcium channel blocker.

 ACE inhibitor, e.g.:

• Enalapril, oral, 10 mg daily.

OR

      Long-acting calcium channel blocker, e.g.:

• Amlodipine, oral, 5 mg daily.

If target blood pressure is not reached after one month despite adequate adherence, add one of ACE inhibitor or calcium channel blocker, whichever has not already been used.

If target blood pressure is not reached after one month despite adequate adherence, add a -blocker.

 -blocker , e.g.:

• Atenolol, oral, 50 mg daily.

If target blood pressure is not achieved after one month despite adequate adherence, increase the dose of drugs, one drug every month, to their maximal levels: enalapril 10 mg 12 hourly, amlodipine 10 mg daily and hydrochlorothiazide 25 mg daily.

Note:

In 60–80% of patients a combination of the above antihypertensive therapy is needed. Combination therapy, i.e. hydrochlorothiazide plus a calcium channel blocker or ACE inhibitor should be considered at the outset in patients with BP >160/100 mmHg.

Medicine treatment choices with compelling indications 

Compelling indications	Drug class
Angina	ß-blocker Calcium channel blocker
Coronary artery disease	ß-blocker ACE inhibitor If ß-blocker contraindicated: verapamil
Post myocardial infarction	ß-blocker ACE inhibitor
Heart failure	ACE inhibitor Carvedilol Spironolactone Hydrochlorothiazide or furosemide
Left ventricular hypertrophy	ACE inhibitor
Stroke	Hydrochlorothiazide ACE inhibitor
Diabetes type 1 or 2 with/without evidence of microalbuminuria or proteinuria	ACE inhibitor, usually in combination with a diuretic.*
Chronic kidney disease	ACE inhibitor, usually in combination with a diuretic.
Isolated systolic hypertension	Hydrochlorothiazide Calcium channel blocker
Pregnancy	See Chapter 6
Prostatism	Alpha-blocker

Caution

Lower BP over a few days.

A sudden drop in BP can be dangerous, especially in the elderly. BP should be controlled within 1–6 months.

Risk assessment: 10 year risk of MI > 20%:

        HMGCoA reductase inhibitors e.g.:

• Simvastatin, oral, 10 mg daily.

This therapy requires good initial evaluation, ongoing support for patients and continuousevaluation to ensure compliance.

Therapy should be initiated together with appropriate lifestyle modification and adherence monitoring.

See section 3.1: Ischaemic heart disease and atherosclerosis, prevention.

REFERRAL

Referral is dynamic and patients can be referred up to a specialist or down to PHC when controlled. Consultation without referral may be all that is necessary.

Referrals are indicated when:

» Patients are compliant with therapy, and the blood pressure is refractory, i.e. >140/90 mmHg, while on drugs from three to four different classes at appropriate dose, one of which is a diuretic.

»     All cases where secondary hypertension is suspected.

» Complicated hypertensive urgency e.g. malignant/accelerated hypertension, severe heart failure with hypertension and hypertensive emergency.