An estimated 1.1 billion people worldwide have hypertension with the condition affecting approximately one third of adults in the UK; however, this figure rises to more than two in three for those over the age of seventy-five.
Hypertension causes brain clots and blocked arteries, which can result in strokes or heart attacks. Although a number of clinical trials have shown the benefit of hypertensive drug treatment on stroke, cardiovascular events and mortality, very few studies include the very elderly (corresponding to WHO ‘oldest-old’ as people aged 80 years and over). This has not only generated concerns that treatment for this demographic may be harmful, but it also raises ethical questions over whether this population is being denied the opportunity to benefit from clinical treatment.
HYVET trial investigates the benefits and risks of antihypertensive treatment in the elderly.
Brighton and Sussex Medical School (BSMS) research into hypertension has, for the first time, provided blood pressure targets for the very elderly to reduce the risk of death due to stroke or heart attack. Professor Chakravarthi Rajkumar was a key co-investigator in the HYVET trial, a project funded by the British Heart Foundation and the pharmaceutical company, the Institut de Recherches Internationales Servier, led by Professor Bulpitt (Hammersmith Hospital, Imperial College) and Professor Fletcher (London School of Hygiene and Tropical Medicine) and through it, the researchers were able to provide clinical guidance on hypertension in the UK and to change clinical practice and the treatment of hypertension in the very elderly in England.
Increasing age is a major predictor of death from stroke, with rates as high as 52 per cent in people over eighty. The HYVET Trial was conceived to provide the research evidence to resolve clinical uncertainty about the relative benefits and risks of antihypertensive treatment in the elderly. After two years of treatment the mean blood pressure reduced in the trialled patients, with 30 per cent reduction in the rate of fatal or non-fatal stroke, similar reductions in deaths from cardiovascular causes, and a 64 per cent reduction in the rate of heart failure.
The HYVET trial provided the research-based evidence needed to establish a blood pressure target within national and international healthcare guidelines, a measure specifically for the treatment of hypertension in the over eighties. As a result, General Practitioners in England now have a set blood pressure thresholds to refer to when considering hypertensive treatment in this age group. HYVET is the key evidence cited in international guidelines to treat high blood pressure in people aged 80 years and over, and by providing this guidance to healthcare professionals, it has contributed to improved quality of care worldwide. Meanwhile, data collected from GP practices across England confirms that the blood pressure targets in the very elderly, informed by the HYVET trial, have been met in up to 80 per cent of patients treated for hypertension at GP practices in England.