Ambulatory Blood Pressure Monitoring in the UK
NICE Hypertension Guidelines – Key Priorities
High blood pressure is one of the leading causes of premature morbidity and mortality in the UK, therefore hypertension management is also one of the most common interventions in primary care. National Institute for Health and Care Excellence (NICE) provides guidance and advice to improve health. The new hypertension guidelines include updated recommendations on blood pressure measurement and contain information on the use of ambulatory blood pressure monitoring, blood pressure targets and antihypertensive drug treatment. The guidelines should carefully be considered by healthcare professionals, but the guidance does not replace the professonals' knowledge and skills.
Definitions
Stage 1 hypertension: clinic blood pressure is 140/90 mmHg or higher and ambulatory blood pressure monitoring (ABPM) daytime average or home blood pressure monitoring (HBPM) average blood pressure is 135/85 mmHg or higher.
Stage 2 hypertension: clinic blood pressure is 160/100 mmHg or higher and subsequent ABPM daytime average or HBPM average blood pressure is 150/95 mmHG or higher.
Severe hypertension: clinic systolic blood pressure is 180 mmHG or higher or clinic diastolic blood pressure is 110 mmHg or higher.
Ambulatory blood pressure monitoring – offered automatically above 140/90 mmHg
NICE guidelines contain clear instructions on how to diagnose hypertension. Key priorities include:
1. If clinic blood pressure is equal or above 140/90 mmHg, ambulatory blood pressure monitoring (ABPM) is automatically offered to confirm the diagnosis of hypertension.
2. When ambulatory blood pressure monitoring is used, minimum 2 measurements are necessary to be taken hourly during the patient's usual waking hours. Waking hours are called 'active period' in ambulatory blood pressure monitoring (for example between 08:00 and 22:00). The average value of at least 14 measurements should be used to confirm a diagnosis of hypertension.
3. When using traditional home blood pressure monitoring (HBPM) to confirm a diagnosis of hypertension, ensure that:
- for each blood pressure recording 2 consecutive blood pressure measurements are taken at least with 1 minute difference and with the person seated and
- blood pressure is recorded twice daily in the morning and evening and
- blood pressure recording lasts for at least 4 days, but 7 days are preferable.
Discard measurements taken on the first day and use the average value of all the remaining measurements to confirm a diagnosis of hypertension.
Antihypertensive drug treatment
Antihypertensive drug treatment should be initiated and offered:
1. For people aged under 80 years with stage 1 hypertension who have :
- target organ damage and/or
- established cardiovascular damage and/or
- renal disease and/or
- diabetes and/or
- a 10-year cardiovascular risk equivalent to 20% or higher.
2. For people of any age with stage 2 hypertension
3. For people aged under 40 years with stage 1 hypertension and no evidence of target organ damage, cardiovascular damage, renal disease, diabetes, get a specialist evaluation of secondary causes of hypertension and a more detailed assesement of potential target organ damage.
Monitoring treatment and blood pressure targets
For people with white coat effect, which is a discrepancy of more than 20/10 mmHg between clinic and average daytime ABPM or average HBPM blood pressure measurements at the time of diagnosis, consider ABPM or HBPM as 'confirmation' to clinic blood pressure measurements to monitor the effects of antihypertensive treatment.
Source: NICE clinical guidelines 127 - developed by the Newcastle Guideline Development and research Unit and ipdated by the National Clinical Guideline Centre and the British Hypertension Society