Management of hypertension in adults in primary care: NICE guideline

Diagnosis

The diagnosis of hypertension uses both clinic blood pressure monitoring (CBPM) and ABPM readings (Box 1). If blood pressure measured in the clinic is 140/90 mmHg or higher, a second measurement should be taken during the consultation. If the second measurement is substantially different from the first, take a third measurement. The lower of the last two measurements should be recorded as the clinic blood pressure. Everyone with a clinic blood pressure of 140/90 mmHg or higher should have ABPM to make a diagnosis of hypertension.

ABPM was identified as the most accurate and cost-effective means of confirming the diagnosis of hypertension. The recommended protocol for ABPM measurements is at least twice hourly during the person's normal waking hours (for example, between 8am and 10pm). The average of at least 14 measurements taken over that period should be used to confirm the diagnosis. If ABPM is unsuitable (for example, in people with atrial fibrillation) or not tolerated, then HBPM is a suitable alternative. Blood pressure should be measured using the average of two readings in the morning and two in the evening, over 4–7 days. The readings on the first day should be discarded.

If blood pressure is ≥180 mmHg and/or 110 mmHg on CBPM, treatment should be considered as soon as possible, before the results of the ABPM are available.

CBPM should be used to monitor the response to treatment in all patients except those who have a discrepancy of ≥20/10 mmHg between clinic and HBPM/ABPM readings, in these patients HBPM or ABPM should be used.

Thresholds and targets

The guideline refers to the severity of hypertension in stages (Box 1). Patients with stage 1 hypertension, who are younger than 80 years and who have target organ damage or a 10-year cardiovascular risk of ≥20%, or established cardiovascular disease (CVD) or renal disease, should be offered medication, as should all patients with stage 2 hypertension. The target for treatment is a blood pressure <140/90 mmHg, as the evidence was not found to be sufficient to recommend a lower target. Stage 1 patients without target organ damage or CVD risk >20% are treated with lifestyle advice only, not medication.

Those diagnosed with hypertension aged <40 years should be considered for specialist referral. This is because 10-year cardiovascular risk assessments can underestimate the lifetime risk of cardiovascular events in these people. Those aged >80 years with stage 2 hypertension should be treated, but their blood pressure target should be ≤150/90 mmHg or less. The evidence for treating those aged >80 years is based on the results of the Hypertension in the Very Elderly Trial (HYVET),2 that treated to a target of 150/90 mmHg.

It is especially important to measure standing blood pressure in people with symptoms that are suggestive of postural hypotension. The blood pressure should be measured with the person sitting or lying, and again with the person standing. The person should be standing for at least a minute before the standing measurement is taken. If the systolic blood pressure drops by 20 mmHg or more, further investigation may be necessary and the standing blood pressure should be used in future.

Treatments

The treatment algorithm has been changed, with a greater emphasis on using CCBs for those aged ≥55 years and patients of African or Caribbean descent.

First-line treatment is now ACEI, ARB, or CCB, with an option of diuretic if CCB is not tolerated or the person has oedema or heart failure, or is at high risk of heart failure. ACEI or ARB should be used for those aged <55 years.

The second step is now ACE/ARB with a CCB for most patients.

The third step remains a diuretic but there is a preference for thiazide-like drugs. If diuretic treatment is to be initiated or changed, a thiazide-like diuretic, such as chlortalidone (12.5–25.0 mg once daily) or indapamide (1.5 mg modified-release once daily or 2.5 mg once daily) should be given in preference to a conventional thiazide diuretic such as bendroflumethiazide or hydrochlorothiazide. There was a lack of evidence for thiazide diuretics at the doses commonly prescribed in current practice but the guideline is clear that people who are already well controlled on a thiazide diuretic should continue on the treatment they are taking.

The fourth step for those with resistant hypertension is now to consider using the aldosterone antagonist spironolactone in a low dose (25 mg) if the patient's potassium is below 4.5 mmol/l. For those where the potassium is higher than 4.5 mmol/l, it may be better to use a higher dose of a thiazide-like diuretic.

There is very little evidence available regarding fourth-line therapy options, but what there is points to spironolactone being the likely best choice for many patients. Spironolactone is licensed for the treatment of hyperaldosteronism rather than hypertension, although patients with resistant hypertension and low or low normal potassium are likely to have some element of aldosteronism. Care must be taken with spironolactone if the patient becomes dehydrated; therefore, it is a good idea to advise the patient to temporarily stop the drug if they develop diarrhoea and vomiting or if their fluid intake is restricted.