Hypertension: Diagnosis and Targets — MCCQE Notes

Measurement decides the threshold

The same patient is hypertensive at different numbers depending on the method. This is the part candidates get wrong:

Out-of-office measurement is preferred to confirm the diagnosis, precisely because it identifies white coat hypertension (high in clinic, normal outside — do not treat) and masked hypertension (normal in clinic, high outside — do treat).

A single reading of ≥ 180/110 with evidence of end-organ damage does not need confirmation.

Work-up at diagnosis

Look for secondary causes and for damage already done:

• Bloods: electrolytes, creatinine and eGFR, fasting glucose or HbA1c, lipids
• Urinalysis and urine albumin-to-creatinine ratio
• ECG — left ventricular hypertrophy
• Consider secondary causes when hypertension is severe, resistant, or presents before 30 or after 55: renal artery stenosis, primary aldosteronism (hypokalaemia, resistant), phaeochromocytoma, obstructive sleep apnoea, coarctation, thyroid disease, drugs (NSAIDs, oral contraceptives, decongestants, stimulants, liquorice)

Targets

• Most patients: < 140/90
• Diabetes: < 130/80
• High cardiovascular risk (as defined by SPRINT-type criteria, using AOBP): systolic < 120, which requires intensive monitoring for hypotension, syncope, electrolyte disturbance and acute kidney injury
• CKD: < 140/90 for most, individualised

First-line drug choice

Any of these as monotherapy in uncomplicated hypertension:

• Thiazide/thiazide-like diuretic
• ACE inhibitor or ARB (never both together)
• Long-acting dihydropyridine calcium channel blocker
• Beta-blocker — only under 60, and not first-line otherwise

Compelling indications override the general rule:

• Diabetes with albuminuria, or CKD → ACE inhibitor or ARB
• Post-MI, heart failure → ACE inhibitor/ARB plus beta-blocker
• Black patients without CKD or heart failure → thiazide or calcium channel blocker preferred
• Pregnancy → labetalol, nifedipine or methyldopa; ACE inhibitors and ARBs are contraindicated

Resistant hypertension

Not at target on three drugs including a diuretic, at optimal doses. Before escalating: confirm adherence, confirm technique and cuff size, exclude white coat effect with ambulatory monitoring, review NSAIDs and other culprits, then screen for secondary causes. Spironolactone is the usual fourth agent.