Hypertension

• Hypertension classification:

  • Normal: <135/85 mmHg
  • Stage 1: Clinic BP >= 140/90 mmHg or average HBPM >= 135/85 mmHg
  • Stage 2: Clinic BP >= 160/100 mmHg or average HBPM >= 150/95 mmHg
  • Severe: Systolic >= 180 mmHg or diastolic >= 120 mmHg
• Admit for specialist treatment when blood pressure is >= 180/120 mmHg IF:

  • Papilloedema or retinal hemorrhage is present
  • life-threatening symptoms e.g new-onset confusion, chest pain, signs of heart failure or acute kidney injury
  • NICE also recommend referral if a phaeochromocytoma is suspected - labile or postural hypotension, headache, palpitations, pallor and diaphoresis.
• Non-specialist treatment for severe hypertension:

  • Urgent investigations for target end-organ damage - bloods, urine, ACR, ECG
  • If identified, commence antihypertensive treatment
  • If not, repeat clinic BP in 7 days
• Ambulatory blood pressure monitoring (ABPM):

  • At least 2 measurements per hour during the person's waking hours
  • Uses the average value of at least 14 measurements
• Home blood pressure monitoring (HBPM):

  • for each BP recording, two consecutive measurements need to be taken, at least 1 minute apart and with the person seated
  • BP should be recorded twice daily, ideally in the morning and evening
  • BP should be recorded for at least 4 days, ideally for 7 days
  • discard the measurements taken on the first day and use the average value of all the remaining measurements
• Hypertension classification:

  • Essential hypertension - most common and caused by a wide variety of factors e.g.  age, family history, obesity, high salt intake, sedentary lifestyle, and alcohol consumption.
  • Secondary hypertension - often a result of an underlying comorbidity
• Renal diseases that can cause hypertension:

  • glomerulonephritis
  • chronic pyelonephritis
  • ADPKD
  • Renal artery stenosis
• Endocrine disorders that can cause hypertension:

  • primary hyperaldosteronism
  • phaeochromocytoma
  • Cushing's syndrome
  • Liddle's syndrome
  • Congenital adrenal hyperplasia (11-beta hydroxylase deficiency)
  • Acromegaly
• Causes of secondary hypertension:

  • Renal disease
  • Endocrine disorders
  • Glucocorticoids
  • NSAIDs
  • Pregnancy
  • Coarctation of the aorta
  • Combined oral contraceptive pill
• Lifestyle management for hypertension:

  • Low salt diet - aiming for less than 6g/day
  • Reduced caffeine intake
  • General advice - smoking cessation, reducing weight, reducing alcohol intake, balanced diet, more exercise
• Hypertension treatment criteria:

  • Stage 1 (ABPM/HBPM>135/85) - treat if < 80 years of age AND any of the following apply; target organ damage, established cardiovascular disease, renal disease, diabetes or a 10-year cardiovascular risk equivalent to 10% or greater
  • Stage 2 (ABPM/HBPM>150/95) - offer drug treatment regardless of age
  • For patients >40 years of age, refer to specialist to exclude secondary cause
• Hypertension management:

  A) <55 or type 2 diabetes

  B) >=55 years with no type 2 diabetes

  C) Black African or African Caribbean ethnicity

  D) A

  E) A + C or A + D

  F) C

  G) C + A or C + D

  H) A + C + D

  I) If K <= 4.5 add spironolactone

  J) If K >4.5 add an alpha or beta blocker

  K) If BP not controlled on 4 drugs then specialist review

  
• Drugs employed in hypertension management:

  • ACE inhibitors
  • Angiotensin II receptor blockers
  • Calcium channel blockers
  • Thiazide like diuretics
  • Spironolactone
  • Alpha and beta blockers
• Blood pressure targets:

  • Age <80 years - clinic BP 140/90 mmHg or ABPM/HBPM 135/85 mmHg
  • Age >80 years - clinic BP 150/90 mmHg or ABPM/HBPM 145/85 mmHg
• Neurological influence on hypertension:

  • Increased sympathetic nervous system activity contributes to hypertension by promoting vasoconstriction, increased heart rate, and increased renin release from the kidneys.
• Renal influence on hypertension:

  • The kidneys play a critical role in blood pressure regulation through sodium and water balance. Impaired renal function, reduced glomerular filtration rate, or abnormalities in the RAAS can contribute to the development of hypertension.
• Endocrine and hormonal influence on hypertension:

  • Dysregulation of the RAAS, including increased production of angiotensin II and aldosterone, can result in vasoconstriction, sodium retention, and hypertension. Additionally, endothelial dysfunction, characterized by reduced nitric oxide production and increased endothelin-1 levels, can cause increased peripheral resistance and elevated blood pressure.
• Vascular influence on hypertension:

  • Structural and functional changes in the vasculature, such as increased arterial stiffness and impaired vasodilation, can contribute to the development of hypertension.
• Lifestyle risk factors for hypertension:

  • Obesity
  • High salt intake
  • Excessive alcohol consumption
  • Lack of exercise
• Cardiovascular complications of hypertension:

  • Coronary artery disease - and subsequently myocardial infarction
  • Heart failure
  • Atrial fibrillation
• Cerebrovascular complications of hypertension:

  • Stroke
  • Vascular dementia
• Renal complication of hypertension:

  • Chronic kidney disease
• Ocular complications of hypertension:

  • Hypertensive retinopathy
  • Glaucoma
• Peripheral vascular complications of hypertension:

  • Peripheral artery disease
  • Aortic aneurysm