New approaches should be used to treat and diagnose high blood pressure, according to draft guidelines today published by the National Institute for Health and Clinical Excellence (NICE). The proposed changes include lending patients a monitor device to be worn at home for 24 hours to confirm blood pressure, and using revised criteria to decide when a patient should be given medication.
The extensive new guidelines, which are still subject to revision, come as part of a routine NICE review of the options available for treating high blood pressure, medically known as hypertension. People with the condition may not show any outward symptoms but may have problems such as kidney damage and an increased risk of heart disease, heart attack and stroke.
The move towards monitoring at home is in part designed to bypass the “white coat effect”, the phenomenon where nervousness causes certain patients to experience a temporary rise in blood pressure when being tested by a doctor. NICE has also re-examined the evidence for treatment of specific groups, such as people aged over 80 and people with high blood pressure that is resistant to medication.
What is the white coat effect?
It is thought that up to a quarter of patients experience a temporary increase in blood pressure while having their blood pressure measured by their doctor. This can potentially suggest that a patient has high blood pressure when it would be within a healthy range during everyday life. The effect can also make it appear that an individual’s high blood pressure is worse than it is. The effect is more common in older people and among pregnant women.
The draft guidelines define white coat hypertension as a patient having persistently elevated blood pressure in a clinical setting but a normal daytime average (below 135/85mmHg) when read using the home methods recommended in the draft guidelines.
While the effect has been discussed since the 1940s, it is generally poorly understood. For example, NICE says it is unclear whether the benefits of treatment differ substantially in those with or without white coat hypertension.
What do the draft guidelines say?
The extensive draft guidelines feature both new guidance and updates to existing NICE recommendations.
One major new recommendation is that diagnoses of high blood pressure should be confirmed by offering patients a form of testing known as 24-hour ambulatory blood pressure monitoring (ABPM). The process involves wearing a type of mobile blood pressure monitor that records numerous blood pressure measurements throughout the day and night. NICE says the move will provide better diagnosis than simply relying on measurements in a clinical setting, and will help avoid the white coat effect.
The guidelines also recommend that doctors look for evidence of organ damage and perform a formal assessment of cardiovascular risk when considering a diagnosis of high blood pressure.
The draft guidelines also feature updated guidance on blood pressure targets, the use of blood pressure medication, treatment of people aged over 80, treatment of adults under 40 and drug-resistant high blood pressure.
Are these new guidelines official?
No. These are currently only draft guidelines and they have not yet replaced NICE’s official guidance on high blood pressure, published in 2006. When NICE creates or updates guidelines, it initially creates a detailed draft version that must be subjected to a formal consultation process before it becomes official. This consultation allows relevant medical organisations, such as patient groups, the NHS and medical bodies, to provide their input. This may cause the draft guidelines to change before they are made official.
The official guidelines created from these draft proposals are scheduled to be published in August 2011.
I’ve been diagnosed with high blood pressure. What should I do?
If you think your blood pressure may have been read incorrectly, do not stop taking your medication. If you have concerns about your medication or the white coat effect, your GP can give you advice.