Background Information

Definition

NICE defines hypertension as:

• ≥140/90 mmHg persistent clinical reading, OR
• ≥135/85 mmHg on 24-hour blood pressure average reading

A few important types of hypertension:

• Primary hypertension (essential hypertension): persistently raised BP without an identifiable underlying cause
• Secondary hypertension: persistently raised BP in the presence of an identifiable underlying cause
• Accelerated / malignant hypertension: BP ≥180/120 mmHg + signs of retinal haemorrhage and/or papilloedema
• Resistant hypertension: BP ≥140/90 mmHg, despite triple drug therapy

Staging of Hypertension

The staging of hypertension is important in guiding management and stratifying severity.

Clinical Features

Typically asymptomatic and diagnosed on incidental findings.

Possible clinical features in severe hypertension or even malignant hypertension:

Diagnosis

Measuring Blood Pressure

Always measure BP in both arms:

• If difference >15 mmHg → repeat measurements
• If difference remains >15 mmHg → measure and record BP in the arm with the higher reading

If clinic BP ≥140/90 mmHg:

• Repeat the measurement → record the lower reading

Investigation and Diagnosis

The approach largely depends on the recorded clinic BP, and importantly referring patients as needed.

Stage 3 Hypertension (BP >180/120 mmHg)

Immediately assess for:

• Retinal haemorrhage or papilloedema (presence of any indicates malignant / accelerated hypertension)
• Life-threatening symptoms
  • New-onset confusion
  • Chest pain
  • Signs of heart failure 
  • Signs of AKI

Subsequent actions:

• If any of the above is present → refer for same-day specialist assessment
• If referral not indicated → urgent investigation for target organ damage
  • Target organ damage present → consider starting drug treatment immediately without confirming diagnosis
  • No target organ damage → repeat clinic BP within 7 days OR ABPM / HBPM

Stage 1-2 Hypertension (BP 140-90 – 180/120 mmHg)

Perform the following: (see below for more details)

1. Confirm hypertension diagnosis 
2. Assess for target organ damage
3. Assess cardiovascular risk

1. Confirm Hypertension Diagnosis

1st line: ambulatory blood pressure monitoring (ABPM)

• ABPM involves wearing a portable BP cuff under the clothes for 24 hours, while the person carry on normal daily activities and sleep
• The cuff automatically record BP regular intervals – ≥2 measurements/hour during person’s waking hours
• To confirm hypertension: use average of ≥14 measurements taken during person’s waking hours

2nd line: home blood pressure monitoring (HBPM)

• For each recording: take 2 consecutive measurements, ≥1 minute apart with the person seated
• Record BP twice daily (ideally morning and evening)
• Record BP for at least 4 days (ideally 7 days)
• To confirm hypertension: discard recording from day 1 (practice day), use average of all the remaining measurements

Diagnosis of hypertension is confirmed if:

• Clinic BP ≥140/90 mmHg, AND
• ABPM / HBPM average ≥135/85 mmHg

2. Assess for Target Organ damage

Perform all the following:

• Fundoscopy (to check for hypertensive retinopathy)
• 12-lead ECG
• Bloods: HbA1c, U&E, eGFR, total and HDL cholesterol
• Urine: ACR and reagent strip to test for haematuria

3. Assess Cardiovascular Risk

NICE recommends QRISK3 tool to estimate 10-year risk of CVD in 25-84 y/o patients without cardiovascular diseases.

See the Lipid Lowering Therapy and Cardiovascular Risk Reduction article to see how to manage cardiovascular risk and how to manage patients with established cardiovascular diseases.

BP <140/90 mmHg

Check BP at least every 5 years or more often.

Management

Approach

All patients: advise on lifestyle interventions

• A healthy balanced diet, including ↓ dietary sodium intake
• Healthy exercise pattern
• Avoid excessive consumption of caffeine
• Smoking cessation
• ↓ Alcohol consumption

Only start drug therapy in:

• Stage 2 hypertension (regardless of age)
• Stage 1 hypertension + <80 y/o + ANY of the following
  • QRISK3 ≥10%
  • Target organ damage
  • Established CVD
  • Diabetes
  • Renal disease

Choice of Anti-Hypertensive Drugs

Examples of commonly used anti-hypertensive drugs:

Step 1 – Monotherapy

• If T2DM (regardless of anything) → ACE-I / ARB
• No T2DM
  • >55 y/o → CCB
  • Afro-Caribbean of any age → CCB
  • <55 y/o and NOT Afro-Caribbean → ACE-I / ARB

Step 2 – Dual Therapy

Add 1 of the following to the current regimen (depending on what the patient is already taking):

• ACE-I / ARB
• CCB
• Thiazide-like diuretic

Step 3 – Triple Therapy

Give a combination of:

• ACE-I / ARB
• CCB
• Thiazide-like diuretic

Step 4 – Quadruple Therapy

First, perform the following:

• Confirm resistant hypertension with ABPM or HBPM
• Discuss adherence to medication
• Check for postural hypotension

For confirmed resistant hypertension → seek specialist advice / add a 4th drug (choice depends on blood potassium level):

• Potassium ≤4.5 mmol/L → spironolactone (low-dose)
• Potassium >4.5 mmol/L → alpha blocker (e.g. doxazosin) / beta blocker (e.g. atenolol, bisoprolol)

Always seek specialist advice if BP is not controlled with 4 drugs.

Choice of Anti-hypertensive Drugs in Specific Patient Populations

• Black African or African-Caribbean family origin: ARB is preferred over ACE-I
• Patients with hypertension + CKD + ACR >30 mg/mmol → ACE-I / ARB as 1^st line
  • If ACR ≤30 mg/mmol → follow the above algorithm
• Pregnant patients → see separate article (ACE-I and ARB are teratogenic and should be stopped)

Monitoring and BP Targets

Hypertension patients without T1DM / CKD:

T1DM / CKD patients:

• <80 y/o
  • T1DM / CKD + ACR <70 mg/mmol target: <140/90 mmHg
  • T1DM / CKD + ACR ≥70 mg/mmol target: <130/80 mmHg
• ≥80 y/o
  • All T1DM (regardless of ACR): <150/90 mmHg
  • CKD + ACR <70 mg/mmol target: <140/90 mmHg
  • CKD + ACR ≥70 mg/mmol target: <130/80 mmHg

References

Original Flowchart – Diagnosis and Treatment

Original Flowchart – Choice of Drug, BP Targets, Monitoring