Three recent papers recently published in The Lancet, and a further study in The Lancet Neurology, show that it is variability in patients’ blood pressure that is more likely to predict the risk of a stroke than a high average or usual blood pressure level.
The results of the studies, led by Professor Peter Rothwell and colleagues at the University of Oxford, some of whom are supported by the Oxford NIHR Biomedical Research Centre, have major implications for the diagnosis and treatment of high blood pressure in prevention of stroke and heart disease.
‘Raised blood pressure, or hypertension, accounts for over 50% of the risk of stroke and other vascular events in the population,’ says Professor Rothwell of the Department of Clinical Neurology.
‘It has long been believed that it is the underlying average blood pressure that determines most of the risk of complications from hypertension and all of the benefit from the drugs that are used to lower blood pressure. The work that we have done shows that this hypothesis is only partly true – at least when it comes to stroke, the most common complication of hypertension,’ he adds.
In the four papers, Professor Rothwell and colleagues show that variability in blood pressure is important as well as a raised average blood pressure.
Raised blood pressure, or hypertension, accounts for over 50% of the risk of stroke and other vascular events in the population.
‘We have shown that it is variations in people’s blood pressure rather than the average level that predicts stroke most powerfully. Occasional high values, and what might be called episodic hypertension, carry a high risk of stroke. Previously, such fluctuations were considered to be benign and uninformative,’ says Professor Rothwell.