Hypertension

 

Hypertension is persistently raised arterial blood pressure. Blood pressure is normally distributed in the population and there is no natural cut-off point above which 'hypertension' definitively exists. Arbitrary thresholds are therefore used to define hypertension.  Hypertension is a major risk factor for ischaemic and haemorrhagic stroke, myocardial infarction, heart failure, chronic kidney disease, cognitive decline and premature death

Primary hypertension has no identifiable cause (accounts for about 90% of people with hypertension).  Secondary hypertension (about 10% of people) is the result of a known underlying cause such as Conn's adenoma, renovascular disease, or phaeochromocytoma.  The prevalence of hypertension in adults in England in 2015 was 31% in men and 26% in women

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Risk factors

Risk factors for hypertension include:

  1. Age — blood pressure tends to rise with advancing age
  2. Sex — Up to about 65 years, women tend to have a lower blood pressure than men. Between 65 to 74 years of age, women tend to have a higher blood pressure
  3. Ethnicity — people of Black African and Black Caribbean origin are more likely to be diagnosed with hypertension
  4. Genetic factors — research on twins suggest that up to 40% of variability in blood pressure may be explained by genetic factors
  5. Social deprivation — people from the most deprived areas in England are 30% more likely to have hypertension than those from the least deprived
  6. Lifestyle — smoking, excessive alcohol consumption, excess dietary salt, obesity, and lack of physical activity are associated with hypertension
  7. Anxiety and emotional stress — can raise blood pressure due to increased adrenaline and cortisol levels

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Severity criteria

Classify the severity of confirmed hypertension using the following criteria:

  1. Stage one hypertension — clinic blood pressure at least 140/90 mmHg, and subsequent ABPM daytime average or HBPM average at least 135/85 mmHg
  2. Stage two hypertension — clinic blood pressure at least 160/100 mmHg, and subsequent ABPM daytime average or HBPM average is at least 150/95 mmHg
  3. Severe hypertension — clinic systolic blood pressure at least 180 mmHg or clinic diastolic blood pressure at least 110 mmHg
  4. Accelerated hypertension — clinic blood pressure usually higher than 180/110 mmHg with signs of papilloedema and/or retinal haemorrhage

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Diagnosis and blood pressure monitoring

Blood pressure monitoring

  1. When considering a diagnosis of hypertension, measure blood pressure in both arms:
    1. If the difference in readings between arms is more than 20 mmHg, repeat the measurements
    2. If the difference in readings between arms remains more than 20 mmHg on the second measurement, measure subsequent blood pressures in the arm with the higher reading
  2. If blood pressure measured in the clinic is 140/90 mmHg or higher:
    1. Take a second measurement during the consultation
    2. If the second measurement is substantially different from the first, take a third measurement
  3. Record the lower of the last two measurements as the clinic blood pressure
  4. If the clinic blood pressure is 140/90 mmHg or higher, offer ambulatory blood pressure monitoring (ABPM) to confirm the diagnosis of hypertension
  5. If a person is unable to tolerate ABPM, home blood pressure monitoring (HBPM) is a suitable alternative to confirm the diagnosis of hypertension
  6. When using HBPM to confirm a diagnosis of hypertension, ensure that:
    1. for each blood pressure recording, two consecutive measurements are taken, at least 1minute apart and with the person seated and
    2. blood pressure is recorded twice daily, ideally in the morning and evening and
    3. blood pressure recording continues for at least 4 days, ideally for 7 days

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Drug treatment

  1. If the person has severe hypertension, consider starting antihypertensive drug treatment immediately, without waiting for the results of ABPM or HBPM

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Referral and review

Referral

  • Refer the person to specialist care the same day if they have:
    • accelerated hypertension, that is, blood pressure usually higher than 180/110 mmHg with signs of papilloedema and/or retinal haemorrhage or
    • suspected phaeochromocytoma (labile or postural hypotension, headache, palpitations, pallor and diaphoresis)
  • Consider the need for specialist investigations in people with signs and symptoms suggesting a secondary cause of hypertension

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Review

  • If hypertension is not diagnosed, measure the person's clinic blood pressure at least every 5 years subsequently, and consider measuring it more frequently if the person's clinic blood pressure is close to 140/90mmHg

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Assessment of cardiovascular risk and organ damage

  1. While waiting for confirmation of a diagnosis of hypertension, carry out investigations for target organ damage (such as left ventricular hypertrophy, chronic kidney disease and hypertensive retinopathy) and a formal assessment of cardiovascular risk using a cardiovascular risk assessment tool (QRISK2)
  2. If hypertension is not diagnosed but there is evidence of target organ damage such as left ventricular hypertrophy, albuminuria or proteinuria, consider carrying out investigations for alternative causes of the target organ damage

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Lifestyle advice

Click here for information for the Drug & Alcohol Service, Exercise Referral Scheme, Healthy Weight Service and Smoking Cessation

Further information can be found on the CVD Prevention page

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Initiating and monitoring antihypertensive drug treatment

Initiating Treatment

  1. Offer antihypertensive drug treatment to people aged under 80 years with stage 1 hypertension who have one or more of the following:
    1. target organ damage
    2. established cardiovascular disease
    3. renal disease
    4. diabetes
    5. a 10-year cardiovascular risk equivalent to 20% or greater
  2. Offer antihypertensive drug treatment to people of any age with stage 2 hypertension
  3. For people aged under 40 years with stage 1 hypertension and no evidence of target organ damage, cardiovascular disease, renal disease or diabetes, consider seeking specialist evaluation of secondary causes of hypertension and a more detailed assessment of potential target organ damage. This is because 10-year cardiovascular risk assessments can underestimate the lifetime risk of cardiovascular events in these people

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Monitoring treatment and blood pressure targets

  1. Aim for a target clinic blood pressure below 140/90 mmHg in people aged under 80 years with treated hypertension
  2. Aim for a target clinic blood pressure below 150/90 mmHg in people aged 80 years and over, with treated hypertension

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Choosing antihypertensive drug treatment

Step 1 Treatment

  1. Offer people aged under 55 years step 1 antihypertensive treatment with an angiotensin-converting enzyme (ACE) inhibitor or a low-cost angiotensin-II receptor blocker (ARB). If an ACE inhibitor is prescribed and is not tolerated (for example, because of cough), offer a low-cost ARB
  2. Do not combine an ACE inhibitor with an ARB to treat hypertension
  3. Offer step 1 antihypertensive treatment with a calcium-channel blocker (CCB) to people aged over 55 years and to black people of African or Caribbean family origin of any age. If a CCB is not suitable, for example because of oedema or intolerance, or if there is evidence of heart failure or a high risk of heart failure, offer a thiazide-like diuretic

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Step 2 Treatment

  1. If blood pressure is not controlled by step 1 treatment, offer step 2 treatment with a CCB in combination with either an ACE inhibitor or an ARB

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Step 3 Treatment

  1. Before considering step 3 treatment, review medication to ensure step 2 treatment is at optimal or best tolerated doses
  2. If treatment with three drugs is required, the combination of ACE inhibitor or angiotensin II receptor blocker, calcium-channel blocker and thiazide-like diuretic should be used

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Step 4 Treatment

  1. Regard clinic blood pressure that remains higher than 140/90 mmHg after treatment with the optimal or best tolerated doses of an ACE inhibitor or an ARB plus a CCB plus a diuretic as resistant hypertension, and consider adding a fourth antihypertensive drug and/or seeking expert advice

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Annual review

  1. Discuss the person's lifestyle, symptoms, and (if applicable), medication, including any adverse effects
    1. If necessary, use interventions to overcome medication non-adherence, such as suggesting the recording of medicine-taking, encouraging monitoring of the condition, simplifying the dosing regimen, and/or using a multi-compartment medicines system
  2. Check clinic blood pressure:
    1. If blood pressure is above the target range, confirm that it is persistently raised by:
      1. Either, rechecking blood pressure on 2–3 occasions over the next few weeks or months depending on clinical judgement
      2. Or,  if a 'white coat effect' is suspected, consider ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM)
      3. If blood pressure is persistently raised above the target range, ensure that secondary causes for hypertension have been excluded, and consider additional antihypertensive drug treatment
    2. If blood pressure is within the target range:
      1. If adverse effects of the current antihypertensive drug treatment are unacceptable, consider an alternative treatment
      2. If treatment is well tolerated, either, review the person in a further 12 months, or consider a trial of stopping or reducing antihypertensive drug treatment
  3. Check renal function annually by measuring serum creatinine, electrolytes, and estimated eGFR, and dipstick urine to check for proteinuria
    1. If proteinuria is present, consider checking the urine albumin:creatinine ratio (ACR), ideally tested on a first-void morning urine sample
  4. For people who are not on an antiplatelet drug or statin reassess their cardiovascular disease risk using the QRISK2 assessment tool

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QRISK

The QRISK2 risk calculator is an algorithm designed to calculate a person's risk of developing cardiovascular disease over the next 10 years by answering some simple questions

The online algorithm can be found here

Advice and Guidance is being made available for all specialties, and is being provided by consultant specialists at East Kent Hospitals.  To make a request or to check to if a query has been answered, you will need to log in via the electronic Referral System (eRS)

Click here for the "how to access" e-Referral Advice and Guidance Manual for instructions on how to make a request and check responses

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