Hypertension

Definition

is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated.

Epidemiology

About 30% of people aged 45-54 years have blood pressure (BP) that is at least 140/90 mm Hg. About 70% of people aged 75 years or older have BP that is at least 140/90 mm Hg.

Presentation

Usually asymptomatic (except malignant HTN) Cardiac enlargement Features of underlying causes, eg: radiofemoral delay, palpable kidney

Causes

Primary/Essential/Idiopathic -95%

Secondary

Renal	Intrinsic renal disease(75%)- glomerulonephritis, PAN, systemic scelosis, chronic pyelonephritis, PKD Renovascular disease(25%) –atheromatous,  fibromascular dysplasia Renin producing tumour
Endocrine	Thyroid disease – hyperparathyroidism Adrenal – Cushing, Conn (Primary aldosternism), Phaechromocytoma
Others	Coarctation of aorta, pregnancy, sleep apnea, stress, drugs(alcohol, cocaine)

Investigation

U&E Creatinine cholesterol glucose ECG urine analysis Specific: (exlclude secondary cause) renal US renal arteriography 24h ambulatory BP monitoring (always lower, add-on 12/7 mmHg)

Hypertensive retinopathy

I	Tortuous arteries with thick shiny walls (silver or copper wiring)
II	A-V nipping (narrowing where arteries cross veins)
III	Flame haemorrhages and cotton wool spots
IV	Papillodema

Other considerations

Malignant (accelerated) hypertension:	this is a syndrome characterised by severe hypertension (e.g. systolic >200, diastolic>130 mm Hg) accompanied by encephalopathy or nephropathy, or by papilloedema and/or angiopathic haemolytic anaemia. Accelerated hypertension needs urgent (same day) assessment and treatment.
Hypertensive crisis:	a systolic blood pressure (BP) ≥180 mm Hg or a diastolic BP ≥120 mm Hg is considered a "hypertensive crisis". Treatment should safely reduce BP. Immediate reduction in BP is required only in patients with acute end-organ damage.
Systolic or diastolic pressure	for many years diastolic pressure was considered to be more important than systolic pressure. However, evidence from the Framingham study and the Multiple Risk Factor Intervention Trial (MRFIT) study indicates that systolic pressure is the most important determinant of cardiovascular risk.
Hypertension in the elderly:	Although age-related, rise in systolic pressure can be considered part of the 'normal' ageing process, isolated systolic hypertension (ISH) in the elderly should not be ignored; the benefits of treatment are far greater than treating moderate hypertension in middle-aged patients.

Management

Category	Systolic (mmHg)	Diastolic (mmHg)	Management
Normal	<120	<80	-
Pre-hypertension	120-139	80-89	Reassess in 5 years, advice on healthy lifestyle
Stage 1	140-159	90-99	CHD+stroke risk<20% and no target organ damage - advice and reassess every year
Stage 2	>160	>100	CHD+stroke risk>20% over 10y and no target organ damage or diabetes- advice and reassess every year
isolated systolic hypertension	>140	<90

Antihypertensive therapy choices

Initial Drug Choices

If the patient is young (<55) and non-black, start with: (A) Angiotensin-converting enzyme (ACE) inhibitor or Angiotensin-II receptor antagonist.

If the patient is black or aged ≥55 years, use: (C) Calcium-channel blocker or (D) Diuretic (thiazide).

Second Drug Choices

(A+C) ACE inhibitor or Angiotensin II receptor antagonist with Calcium-channel blocker or (A+D) ACE inhibitor or Angiotensin II receptor antagonist with Diuretic (thiazide)

Third Drug Choices

(A+C+D) ACE inhibitor or Angiotensin II receptor antagonist and Calcium channel blocker and Diuretic (thiazide).

Explain the need for long-term treatment: Remember that most drugs take 4-8 weeks to produce their maximum effect Betablockers are no longer recommended by NICE as first-line therapy, as they may be less effective in reducing major cardiovascular events, particularly stroke, than other drug combinations. They may be appropriate in younger individuals who cannot tolerate ACE inhibitors or angiotensin-II receptor antagonists. Co-prescribing betablocker with a calcium-channel blocker is better than a betablocker with a thiazide because of increased risk of developing diabetes. If this combination is unavoidable, consider screening for diabetes regularly. When hypertensive patients on betablockers are reviewed, the drug should be continued if there is a compelling indication for their use.