Medical guidelines for the treatment of hypertension challenged by Australian researchers
Sydney, Australia: Medical researchers from The George Institute for International Health at the University of Sydney have challenged current practice in the diagnosis and treatment of people with hypertension (high blood pressure).
In a report published today in the prestigious medical journal, The Lancet, the researchers state current medical guidelines in the US, Europe and Australia would classify as many as one-third of all adults as having hypertension.
The researchers suggest that many of those who would be diagnosed are otherwise healthy, and have only mildly raised blood pressures with little to gain from the antihypertensive drugs usually prescribed.
Professor Stephen MacMahon, Principal Director of The George Institute and one of the authors of the report said, "For too long guidelines have supported the belief among doctors and patients that hypertension is a disease — for the vast majority it is not."
While raised blood pressure is a cause of stroke and heart attack, Professor MacMahon said, "this should not be interpreted as indicating that if you have a raised blood pressure you must
be at high risk of stroke or heart attack."
"For many people with mildly raised blood pressure and no other risk factors such as high cholesterol, diabetes or smoking, the probability of having a stroke or heart attack is very low, often less than one percent per year."
The researchers argue that blood pressure lowering treatment should be targeted to high risk patients such as those with multiple risk factors for stroke or heart disease or a history of these conditions.
Co-author of the report, Professor Bruce Neal, Director of the Heart and Vascular Division of The George Institute said, "There is now a large body of evidence showing that blood pressure lowering drugs provide important benefits for high-risk patients, even in the absence of hypertension."
"We have shown that a patient with average or below average blood pressure who has had a stroke in the past will gain much more from blood pressure lowering treatment than a young healthy person with mild hypertension" said Professor Neal.
The researchers suggest that the persisting focus of guidelines on hypertension without adequate attention to the actual risks of stroke or heart attack, in part reflects the historical origins of blood pressure lowering drugs.
"Originally, antihypertensive drugs were developed for the treatment of patients with malignant hypertension, a now rare condition associated with a vastly worse outcome than that of mild hypertension", states Professor MacMahon.
They also argue that this focus is perpetuated by medical societies and other professional groups that portray hypertension as a disease rather than one factor among several that predict risk of cardiovascular diseases.
In 2002, worldwide sales of antihypertensive drugs exceeded USD 36 billion. The top three drugs alone accounted for more than USD 8 billion in sales.
"The same expenditure directed to people at high risk of stroke and heart attack would result in much greater avoidance of premature death and disability than does the current investment in the treatment of hypertension", suggested Professor MacMahon.
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