Hypertension diagnosis and management

Quick Overview

Hypertension affects 25% of UK adults and is the single most important modifiable risk factor for cardiovascular disease. NICE NG136 defines a structured diagnostic pathway using ambulatory/home BP monitoring and a staged treatment escalation approach. Accurate diagnosis and achieving target BP reduces stroke risk by 35-40% and MI risk by 20-25%.

Core Facts & Concepts

Diagnostic Thresholds (NICE NG136)

Target BP Values

• <80 years: <140/90 mmHg (clinic) or <135/85 mmHg (ABPM/HBPM)
• ≥80 years: <150/90 mmHg (clinic) or <145/85 mmHg (ABPM/HBPM)
• Type 2 diabetes + kidney/eye/cerebrovascular disease: <130/80 mmHg
• CKD with ACR >70 mg/mmol: <130/80 mmHg

Secondary HTN Screening Indications 🚩

• Age <40 years with no family history
• Resistant HTN (≥3 drugs including diuretic)
• Hypokalaemia (unprovoked or disproportionate)
• Sudden onset or worsening control
• Signs: radio-femoral delay, renal bruit, cushingoid features

Problem-Solving Approach

Diagnostic Pathway (NICE NG136)

1. Clinic BP ≥140/90 mmHg → Offer ABPM (or HBPM if ABPM declined/not tolerated)
2. ABPM protocol: Minimum 14 measurements per 24h (≥2/hour during waking hours)
3. HBPM protocol: 2 consecutive measurements, twice daily (morning/evening), 4-7 days; discard day 1, use average of remaining readings
4. Confirm diagnosis using ABPM/HBPM thresholds (not clinic readings)
5. Stage 1 HTN + end-organ damage OR CVD risk ≥10% → Treat
6. Stage 2+ HTN → Treat all patients

Treatment Escalation Steps

Step 1

• <55 years or any age with T2DM: ACE-i or ARB (NOT both)
• ≥55 years or Afro-Caribbean: CCB (rate-limiting if evidence of HF)

Step 2: ACE-i/ARB + CCB

Step 3: ACE-i/ARB + CCB + thiazide-like diuretic (indapamide or chlorthalidone preferred over bendroflumethiazide)

Step 4 (resistant HTN): Add spironolactone 25mg (if K+ ≤4.5 mmol/L) OR increase thiazide-like diuretic OR add alpha/beta-blocker

⚠️ Warning: Check U&Es and eGFR before starting ACE-i/ARB; recheck in 2 weeks. Accept eGFR drop ≤25% and K+ rise to 5.5 mmol/L.

Analysis Framework

Investigating End-Organ Damage (Baseline)

• 📊 Bloods: U&E, HbA1c, lipids, eGFR
• 🫀 ECG: LVH (Sokolow-Lyon >35mm; Cornell voltage >28mm males, >20mm females)
• 💧 Urine ACR: Microalbuminuria (≥3 mg/mmol) indicates renal damage
• 👁️ Fundoscopy: Grade 1-4 retinopathy

Secondary Causes Investigation

Visual Aid

Key Points Summary

✓ Diagnosis requires ABPM/HBPM confirmation: Stage 1 ≥135/85 mmHg; Stage 2 ≥150/95 mmHg

✓ Target BP <140/90 mmHg (<80 years); <150/90 mmHg (≥80 years); <130/80 mmHg if diabetes with complications or CKD with ACR >70

✓ Treatment Step 1: ACE-i/ARB if <55/T2DM; CCB if ≥55/Afro-Caribbean. Step 2: Combine both. Step 3: Add thiazide-like diuretic

✓ Screen for secondary causes if: age <40, resistant HTN (≥3 drugs), hypokalaemia, or sudden onset/deterioration

✓ Resistant HTN (Step 4): Add spironolactone 25mg if K+ ≤4.5 mmol/L; check aldosterone:renin ratio before starting

✓ Monitor U&Es 2 weeks after ACE-i/ARB: Accept eGFR drop ≤25% and K+ up to 5.5 mmol/L

✓ HBPM technique: 2 readings twice daily for 4-7 days, discard day 1, average remaining readings