Radical change proposed in diagnosis of primary hypertension

DIAGNOSIS to confirm primary hypertension should rely on ambulatory blood pressure monitoring away from the clinic to avoid so-called 'white coat' hypertension.

This is one of the main recommendations in new draft NICE guidelines on the diagnosis and treatment of high blood pressure.

Hypertension is one of the most important preventable causes of premature ill health and death in the UK. It is a major risk factor for stroke, heart attack, heart failure, chronic kidney disease and cognitive decline. Primary hypertension is diagnosed when there is no simple identifiable cause of the raised blood pressure but it may be related to obesity, poor diet, physical inactivity or genetic inheritance.

The new draft guideline recommends that a diagnosis of primary hypertension should be confirmed using 24-hour ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM) rather than solely on measurements of blood pressure taken in the clinic. Allied to this, the draft guideline also proposes new thresholds for diagnosis and grades of hypertension which better reflect the values obtained using ABPM.

Professor Bryan Williams, Professor of Medicine, University of Leicester and University Hospitals NHS Trust, Leicester, and Chair of the Guideline Development Group said: "The wealth of new evidence generated since the original guideline was published in 2004, and the subsequent partial update in 2006, has largely served to further validate the recommendations already made. Of perhaps greatest significance are the findings which suggest that the current practice of using a series of blood pressure readings taken in the clinic alone for the diagnosis of hypertension can lead to inaccurate diagnosis.

"The resulting draft recommendation to use ambulatory blood pressure monitoring to confirm a diagnosis of hypertension recognises that the measurement of blood pressure, away from the clinic, in a more usual setting can reduce the over-diagnosis of high blood pressure and unnecessary treatment – for example, because of white-coat hypertension. In addition this new approach would not only improve diagnosis but would ultimately be cost-saving for the NHS."

But there are worries among some GPs that complying with the guidelines could be unfeasible and cost practices thousands of pounds in purchasing additional ambulatory monitoring devices.

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