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Author comments on blood pressure variability and stroke as published in Lancet and Lancet Neurology

12 March 2010

Three studies published at the same time in the Lancet, and a further study in Lancet Neurology, show that it is variability in patients’ blood pressure that predicts the risk of a stroke most powerfully and not a high average or usual blood pressure level.

The results have major implications for diagnosis and treatment of high blood pressure in prevention of stroke and heart disease.

Professor Peter Rothwell of the Department of Clinical Neurology at the University of Oxford is lead author on the papers. He says:

‘Raised blood pressure, or hypertension, accounts for over 50% of the risk of stroke and other vascular events in the population.

‘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.‘

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.

‘Importantly, we have also shown that different blood-pressure-lowering drugs have different effects on blood pressure variability. Some increase the variability, which is bad, and some decrease it, which is good. We also show that these effects correlate with differences in the effectiveness of the drugs in preventing stroke.

The work shows that many patients need blood-pressure-stabilising drugs – a new concept – as well as blood-pressure-lowering drugs.

’For more information please contact the Press Office, University of Oxford on +44 (0)1865 280530 or press.office@admin.ox.ac.uk.  

Notes to Editors:

  • Hypertension affects over 50% of all adults, and a person’s lifetime risk of developing hypertension is about 90%. It is the most common indication given when prescribing drugs, and yet Professor Peter Rothwell believes it is very poorly treated in routine practice.
  •  A press release from the Lancet is available from the journal’s press office: +44 (0)20 7424 4949 or pressoffice@lancet.com
  • Oxford University’s Medical Sciences Division is one of the largest biomedical research centres in Europe. It represents almost one-third of Oxford University’s income and expenditure, and two-thirds of its external research income. Oxford’s world-renowned global health programme is a leader in the fight against infectious diseases (such as malaria, HIV/AIDS, tuberculosis and avian flu) and other prevalent diseases (such as cancer, stroke, heart disease and diabetes). Key to its success is a long-standing network of dedicated Wellcome Trust-funded research units in Asia (Thailand, Laos and Vietnam) and Kenya, and work at the MRC Unit in The Gambia. Long-term studies of patients around the world are supported by basic science at Oxford and have led to many exciting developments, including potential vaccines for tuberculosis, malaria and HIV, which are in clinical trials.