Accelerated Hypertension

Accelerated hypertension (malignant hypertension) is the term used to describe severe hypertension (180mmHg systolic and 110mmHg diastolic) occurring with retinopathy of Grade III (flame haemorrhages, dot and blot haemorrhages, hard and soft exudates) to Grade IV (papilloedema).¹
The finding of accelerated hypertension in a patient demands urgent referral for assessment and treatment in order to minimise end-organ damage and reduce the risk of life threatening events such as myocardial infarction, encephalopathy, and intracerebral or subarachnoid haemorrhage.

Accelerated hypertension may be seen in association with renal disease or may occur as a discrete entity and will occur in approximately 1% of patients with essential hypertension. Average age at presentation is 40 years; men are more commonly affected than women.

Risk Factors

• Cigarette smoking
• Black ethnic origin
• Secondary hypertension sufferers

Accelerated hypertension may occur due to raised renin levels e.g. those found in association with²:

• Unilateral renovascular hypertension
• Renin-secreting neoplasms
• Trauma to the kidneys
• Renal vasculitis e.g. scleroderma, polyarteritis, and SLE
• Pheochromocytoma
• Cocaine abuse
• Clonidine withdrawal
• Sodium-volume overload and low renin levels e.g. acute glomerulonephritis, primary aldosteronism
• Pre-eclampsia/eclampsia

This may be asymptomatic, or may present with any of the many symptoms and/or signs of end organ damage:

• Headache
• Fits
• Nausea and vomiting
• Visual disturbance
• Chest pain
• Neurological deficit e.g. CVA
• Bleeding due to disseminated intravascular coagulopathy (DIC)
• Microangiopathic haemolytic anaemia

The investigation of any patient thought to have accelerated hypertension should be undertaken urgently and by doctors with expertise in this field. Investigations should include¹:

• Full history; including
  • Past medical history
  • Full systems review
  • Drug history including over the counter, herbal remedies and recreational drugs
• Full examination; including
  • Blood pressure measurements lying, standing and in both arms
  • Fundoscopy
  • Neurological examination
• ± Ambulatory blood pressure monitoring
• Urine dip testing for protein and blood
• U &E's
• Blood sugar measurement
• Fasting blood lipids
• ECG
• ±CT/MRI scan of head or kidneys
• ±Plasma renin activity
• ±Plasma aldosterone level
• ±Catecholamine levels
• FBC ± Clotting screen
• ±Creatinine clearance
• ±Auto-antibody levels e.g. anti-nuclear factor

Management of Accelerated Hypertension

• Patients may be admitted to hospital.
• Patients typically have altered blood pressure autoregulation; reducing the blood pressure too fast may result in organ hypoperfusion.
• The initial goal is to reduce the mean arterial pressure by approximately 25% over the first 24-48 hours.
• An arterial line is helpful for continuous titration of blood pressure.
• Sodium and volume depletion may be severe, and volume expansion with isotonic sodium chloride solution must be considered.

General Management

All patients with hypertension should be given advice on lifestyle measures which will help to reduce their overall risk of cardiovascular disease. Such measures include¹:

• Maintaining a body mass index of 20-25 kg/m²
• Reduce salt intake to <100 mmol/day
• Limit alcohol consumption to < 3 units per day for men and 2 units per day for women.
• Regular exercise (at least 30 minutes per day for at least 3 days a week)
• Eat at least 5 portions a day of fresh fruit and vegetables
• Reduce amounts of fat eaten, particularly animal fats

Drug treatment

Many patients will require more than one agent to achieve an acceptable in blood pressure. In severe hypertension it is thought safer to add drugs in a step wise manner until adequate control is achieved, and later stepped down if the fall in blood pressure is greater than desirable.

A: ACE inhibitor or angiotensin receptor blocker, C: Calcium channel blocker, D: Diuretic (thiazide and thiazide-like)
Beta-blockers are no longer preferred therapy for hypertension.³ However, they may be considered in young people who:

• Have intolerance to ACE inhibitors or angiotensin 2 receptor antagonists
• Are women of child-bearing age
• Show evidence of increased sympathetic drive

If hypertension is uncontrolled with a combination of 4 drugs, seek specialist advice.

Additional drug therapies

The use of a statin should be considered in patients below the age of 80, with raised cholesterol levels or with a 10 year risk of cardiovascular disease > 20%.⁴The use of aspirin 75mg may be considered once the blood pressure is controlled to levels of <150/90 in patients over the age of 55 with end organ damage, diabetes or a 10 year risk of cardiovascular disease greater than 20%.

Without treatment accelerated hypertension may result in death within a year in over 90% of patients as a result of end organ damage e.g. MI, CVA or renal failure. The prognosis has improved dramatically over the last few decades, and with optimal treatment the 5 year survival rate is > 80%.