Hypertension (high blood pressure) is a major problem worldwide. The incidence of hypertension increases with age, affecting around 75% of those aged over 70.
Estimates suggest that about 54% of stroke, 47% of ischaemic heart disease and 25% of other cardiovascular diseases are attributable to high blood pressure.
While prevention of hypertension through weight control, exercise and diet is desirable, it is difficult to achieve, leaving control by pharmacological treatment as the most effective intervention. Trials have demonstrated the benefits of drug treatment on stroke mortality and morbidity. These trials included very few people over the age of 80. Moreover there was concern that treatment in this age group might be harmful.
Chris Bulpitt, professor of medicine for the elderly at Imperial College London and Astrid Fletcher, professor of epidemiology and ageing at the School, developed the first randomised controlled trial to evaluate the drug treatment of hypertension in people aged 80 and over, the Hypertension in the Very Elderly trial (HYVET). The trial was particularly important in view of ethical concerns that elderly people were being denied the opportunity to benefit. Conversely, if treatment was harmful this would have major implications for those already on treatment.
Nearly 4,000 patients from 13 countries in Europe, Australasia and North Africa took part and the results showed that drug treatment reduced overall mortality and stroke mortality and the incidence of heart failure. The results also suggested that treatment reduced dementia, although the findings were inconclusive. The trial provided reassurance that the drugs used did not increase the risk of fracture, an important result in the elderly.
The findings were published in the New England Journal of Medicine in 2008 with an accompanying editorial stating that the trial “puts the question of the usefulness of treating hypertension in the very old to rest”. The results gained widespread media attention. From 2009 updated national and international guidelines began to appear recommending the pharmacological treatment of hypertension in those aged 80 and over, all of which cited the HYVET trial as their main source of evidence.
For example, in 2011 the American College of Cardiology and American Hypertension Association published a joint report with the European Society of Hypertension. In the UK, the most influential guidelines are those from the National Institute for Health and Care Excellence (NICE). In 2011 NICE introduced revised guidelines in partnership with the British Hypertension Society. The guidelines are a firm recommendation to offer treatment to people aged 80 and over with high blood pressure.