Antihypertensives can reduce both stroke and mortality in the very elderly, according to preliminary results of a now-halted trial carried out by researchers at Imperial College London, UK.

The 3,845 patient Hypertension in the Very Elderly Trial (HYVET) is the largest ever clinical study to look at the effects of lowering blood pressure solely in those aged 80 and over and has been stopped early after significant reductions in overall mortality in those receiving treatment were observed.

Patients with high blood pressure from across the world were randomised for the double-blind, placebo-controlled trial, which began in 2001, and they were given either placebo or a low-dose diuretic indapamide and an additional ACE inhibitor (perindopril), in tablet form once a day. Definitive figures will not be available until all the data has been collected and the results will be published possibly in March next year but the researchers said that while “we do not want to put an exact figure on the risk reductions at the moment…it is statistically significant."

A number of earlier trials have also demonstrated that reducing blood pressure in the under-80s reduces stroke and cardiovascular events but it was noted that “previous smaller and inconclusive studies also suggested that whilst lowering blood pressure in those aged 80 or over reduced the number of strokes, it did not reduce, and even increased, total mortality”.

Chris Bulpitt, HYVET principal investigator from the Care of the Elderly Department at Imperial, said: "It was not clear prior to our study whether the over-80s would benefit from blood pressure lowering medication in the same way as younger people. Our results are great news for people in this age group because they suggest that where they have high blood pressure, such treatment can cut their chances of dying as well as stroke."

Over the next few months, all HYVET patients will be seen for a final visit and offered the option of switching to indapamide.

Commenting on the announcement, Isabel Lee, research liaison officer at The Stroke Association said that “this trial further supports our knowledge of the role of high blood pressure in stroke” and “around 50,000 strokes could be prevented each year through its control." She noted that an estimated 150,000 people in the UK have a stroke each year with three-quarters being over the age of 65, “so the trials observations are very encouraging news for the UK’s ageing population.”