Traditional blood pressure tests miss thousands at risk

DOCTORS must scrap traditional methods of measuring blood pressure as thousands of dangerously ill patients are being missed, researchers warn today.

They are urging GPs to switch to a technique where patients are sent home with portable devices to wear for 24 hours.

University College London researchers have shown this is far more effective than a one-off reading from an inflatable cuff.

In the largest study of its kind, they found the devices were 50 per cent more accurate at predicting if patients would die from heart disease.

Furthermore, they discovered almost a fifth of adults with normal blood pressure readings using the traditional method actually had high blood pressure.

These patients – said to have ‘masked’ high blood pressure – would ordinarily be sent away by GPs without treatment.

Up to a quarter of adults have high blood pressure but nearly half of these – 6million – have never been diagnosed.

It is known as a silent killer because there are no symptoms but it greatly increases the risk of heart attacks, strokes, kidney disease and dementia.

The portable devices, called ambulatory blood pressure monitors (ABPMs), £500 to £1,000 and there is normally one per GP surgery.

The devices measure blood pressure at intervals of 20 to 30 minutes while patients go about their daily routines. For this reason they are far more accurate as many patients with high blood pressure have normal readings when sat in a chair.

They have been increasingly adopted since 2011, when health watchdog Nice said they were highly effective – but researchers say use is still patchy.

Many surgeries have not yet bought the device and, even when they have, one is not enough to share between 7,000 patients on each register. This study, published in the New England Journal of Medicine, involved the records of 63,910 patients over a ten-year period.

All had their blood pressure measured using the traditional method or the portable device. Researchers then compared their accuracy of predicting whether patients died of heart disease over the ten years.

The new devices were found, on average, to be 50 per cent more accurate at predicting death. Importantly, the study also found that those patients with ‘masked’ high blood presauthor sure, who had a normal reading in traditional method, were the most likely to die.

They had a higher chance of dying from cardiovascular disease than those treated for high blood pressure – most likely as a result of not being prescribed treatment because doctors presumed they were normal. Lead

‘What doctors and medics should use’

Professor Bryan Williams, of University College London, said: ‘This research is a clear game- changer as, for the first time, it definitively shows that blood pressure measured regularly during a 24-hour period predicts the risk of heart disease, stroke and death much better than blood pressure measured in a doctor’s surgery or clinic.

‘Quite simply, measuring blood pressure over 24 hours is what doctors and medics should be using to make clinical decisions about treatment. With a much more accurate assessment of a patient’s blood pressure, doctors will be able to provide the most effective treatments at the earliest opportunity, which will save many more lives.

‘With 1billion people around the world having high blood pressure, this study, the largest ever of its kind, should lead to changes in clinical practice across the world, with the use of ABPM becoming much more commonplace.’

Another disadvantage with the traditional method is that many patients experience sudden high blood pressure when they walk into the consulting room because they patients are anxious or nervous.

Normally GPs suspect their reading is wrong because they are otherwise healthy and they are sent home to measure their blood pressure themselves.

An ideal reading is between 90/60 millimetres of mercury (mmHg) and 120/80mmHg.

If it is significantly higher, there is extra strain on the blood vessels and main organs.

Last month the British Heart Foundation warned the condition was costing the NHS £2billion a year.