High blood pressure - HYVET

The clinical question

We know that lowering blood pressure in people with hypertension (high blood pressure) helps to prevent heart and circulatory events, such as strokes or heart attacks. But there were concerns that the risk of side effects from treatment to lower blood pressure might outweigh any benefits for people over 80. 

Most of the previous hypertension treatment trials had not included elderly people. So there were no clear guidelines whether doctors should prescribe blood pressure lowering drugs to people in this age group. To answer this question, the BHF part funded the ‘Hypertension in the Very Elderly Trial’ (HYVET) led by Professor Christopher Bulpitt at Imperial College London.

What did the study involve?

HYVET was the first large trial of blood pressure-lowering treatment in the very elderly. The trial took place in 195 centres across 13 countries in Europe, China, Australasia and North Africa. 3845 participants who had high blood pressure and were aged 80 or over were randomly assigned to either:

• Take blood pressure lowering drugs. This included a diuretic, and an angiotensin-converting–enzyme (ACE) inhibitor in patients who did not respond well to diuretic treatment. 
• Take placebo medication.

The research team followed up the participants to:

• Determine whether they had a fatal or nonfatal stroke.
• Determine whether experienced a heart or circulatory event, such as a heart attack.
• Record whether they died of any cause.

What did the study show?

The HYVET trial was stopped early in 2007. The results showed:

• An important reduction in the rate of stroke and death from any cause in group taking blood pressure lowering drugs.
• Treating hypertension in this age group was associated with a 30% reduction in the rate of fatal or nonfatal stroke; a 21% reduction in the rate of death from any cause; a 23% reduction in the rate of death from heart and circulatory events; and a 64% reduction in the rate of heart failure.
• Importantly, there was no increase in drug side-effects in the treatment group. 

Why is the study important?

With life expectancy increasing, it is predicted that high blood pressure will become an increasing health problem worldwide. The HYVET trial showed for the first time, and conclusively, the benefits of blood pressure-lowering drug treatment in people aged 80 years or older. These results have shaped guidelines worldwide, including those published by the UK's National Institute for Health and Care Excellence (NICE).

HYVET was named ‘Trial of the Year 2008’ by the Society for Clinical Trials, recognising its major impact in “…providing the basis for a substantial and beneficial change in healthcare”.

Study details

"Hypertension in the Very Elderly Trial"
Award reference:  RG/1997010/10287
Principal Investigator: Professor Christopher Bulpitt, Imperial College London
Trial registration number: NCT00122811

Publication details

Beckett NS, Peters R, Fletcher AE, et al. Treatment of hypertension in patients 80 years of age or older. N Engl J Med. 2008;358(18):1887-98.