Hypertension (HTN)

Normal = <120/80

Elevated = 120-129/80

Hypertension

  • Stage 1 = SBP 130-139 or DBP 80-89

  • Stage 2 = SBP >140 or DBP > 90

24-hour ambulatory definitions of HTN

  • Average of >125/75

  • Day >130/80

  • Night >110/65

Primary HTN Risk Factors:

  • Age

  • Obesity

  • Family history

  • Fewer nephrons

  • High sodium diet

  • Excess alcohol

  • Physical inactivity

  • Social determinants

Secondary causes

Medications

  • Oral contraceptive

  • NSAIDs

  • Antidepressants

  • Corticosteroids

  • Decongestants

  • Weight loss medications

  • Stimulants

Illicit drugs

Primary kidney disease

Primary aldosteronism

Renovascular hypertension

Obstructive sleep apnoea

Phaeochromocytoma

Coarctation of the aorta

Endocrine conditions

  • Cushing’s Syndrome

  • Hypothyroidism

  • Hyperthyroidism

  • Hyperparathyroidism

Complications of HTN

Risk begins to start with blood pressure >115/75

For every 20/10 increase, the risk of death from heart disease doubles

  • Left ventricular hypertrophy

  • Heart failure

  • Ischaemic stroke

  • Intracerebral bleed

  • Ischaemic heart disease

  • Chronic kidney disease

Evaluation

Once established check for

  • The extent of end-organ damage

  • Presence of CVD or CKD

  • Check cardiovascular risk factors

  • Lifestyle factors that could contribute

  • Potential interfering substances

Tests

  • FBC, UEC, Lipids, Glucose, TSH, CMP

  • ECG

  • Calculate 10-year risk

  • Urinalysis + ACR

  • Consider echo

  • Consider testing secondary causes but these are rare

Treatment

  • Weight loss

  • Less salt

  • More potassium

  • Healthy diet

  • Exercise

  • Less Alcohol

Outcomes

Treatment with medication produces

  • 50% risk reduction in heart failure

  • 35% risk reduction in stroke

  • 25% risk reduction in heart attack

This means 100 patients need to be treated for 5 years to prevent an adverse cardiovascular event in 2 patients.

Medication

Three primary options for most patients

  • ACEI or ARB

  • Calcium channel blocker

  • Thiazide

Start at the lowest dose

  • If not to target add 2nd agent

  • Titrate up one of the agents

  • If still not at target, add a third agent

Combinations to avoid

  • ACE inhibitor or ARB plus potassium-sparing diuretic – risk of hyperkalaemia.

  • beta blocker plus verapamil or diltiazem – risk of heart block.

  • ACE inhibitor plus ARB – increased risk of hypotensive symptoms, syncope, and renal dysfunction.

  • Thiazide diuretic and betablocker – not recommended in patients with glucose intolerance, metabolic syndrome, or established diabetes.

  • NSAIDs with ACE inhibitors, ARB, diuretics, and beta blockers.

Effective combinations

  • ACEI or ARB and Ca2+ blocker – Diabetes or lipid abnormalities

  • ACEI or ARB and thiazide diuretic – Heart failure, or post stroke

  • ACEI or ARB and beta blocker – Myocardial infarction (MI) or heart failure

  • Beta blocker and dihydropyridine calcium channel blocker – Heart disease

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