Diagnosis

A 45-year-old man attends for a BP check. The lowest value of 3 measurements is 150/100 mmHg. What is the preferred next step in confirming a diagnosis of hypertension?

1. Echocardiography to confirm left ventricular hypertrophy

2. Renal function test to confirm renal impairment

3. Serial blood pressure measurement

4. Ambulatory blood pressure measurement (ABPM)

5. ECG to confirm left ventricular hypertrophy

In practice, clinical blood pressure measurement (CBPM) is determined by taking at least 3 measurements, one minute apart, with the patient rested and relaxed. The lowest value from the 2nd or 3rd measurement is usually the most reliable.

• If the CPBM is ≥140/90 mmHg and the patient is not known to be hypertensive, confirm hypertension with ABPM, unless this is not tolerated or not available. If ABPM is not available, home blood pressure monitoring (HBPM) is advised if possible.

• With ABPM there should be at least 2 measurements per hour during the person’s usual waking hours (e.g. 08.00 and 22.00). The average value of at least 14 of these measurements is used to confirm the diagnosis.

• For HBPM, it is recommended that the patient takes 2 resting blood pressures, 2 minutes apart, twice daily. They should do this for 4-7 consecutive days and ignore the readings taken on the 1st day. The average reading will be more accurate with a higher number of readings.

• Chronic poorly controlled hypertension is an important cause of LVH.  LVH is often absent in the early stages of hypertensive disease. For this reason ECG and/or echocardiography are not ideal for making the diagnosis of hypertension.

Stage 1 

• ≥140/90 clinic or 

• ≥135/85 ABPM/HBPM

Stage 2 

• ≥160/100 home or

•  ≥150/95 ABPM/HBPM

Stage 3 

• ≥180 or 

• ≥110 diastolic in clinic

Isolated systolic hypertension

• ≥160 systolic

References

• Hypertension in Adults: diagnosis and management (NG 136, 2019)

• High blood pressure (hypertension) (NHS Choices)

• Hypertension - not diabetic (CKS)

• Management of Hypertension (Patient.info)

• Blood pressure lowering and risk of new-onset type 2 diabetes: an individual participant data meta-analysis (Lancet, 2021)

Hypertension in pregnancy

• Hypertension in pregnancy (CKS)

• Hypertension in pregnancy: diagnosis and management (NICE)

Renal function, serum electrolytes and blood pressure should be measured before starting an angiotensin converting enzyme (ACE) inhibitor and again within one or two weeks of starting treatment.

Patients should be monitored as appropriate as the dose is titrated upwards, until the maximum tolerated or target dose is reached, and then at least annually.

More frequent monitoring may be needed in patients who are at increased risk of deterioration in renal function.

Resource:

NICE. Hypertension in adults: diagnosis and management. NG136. 2019 (updated 2022).

A 45-year-old man has the following blood pressure readings taken five minutes apart at a routine health check.

149/92 mmHg

146/94 mmHg

145/93 mmHg

If the lower of the final two clinic readings is 140/90 mmHg or greater, the patient should be offered ambulatory blood pressure monitoring (ABPM), or home blood pressure monitoring if the patient is unable to tolerate ABPM.

Resources:

RCGP. Hypertension in adults: diagnosis and management. EKU. 2021.1: Jan 2020

NICE. Hypertension in Adults: diagnosis and management. NG136. 2019 (updated 2023).

The correct answer is: Ambulatory blood pressure monitoring (ABPM)