Meta-analysis casts doubt on hypertension age guidance
By Lilian Anekwe
A major new study has dramatically reopened the debate over how best to treat hypertension, after concluding there is no evidence to justify choosing drug class on the basis of age.
The BMJ meta-analysis of 31 trials involving more than 190,000 patients found all classes of drugs reduced blood pressure by about the same amount and that age had no clear effect on treatment outcomes.
The researchers insisted the study should greatly simplify decisions over drug choice, while GP experts called for guidance to be amended and the ACD algorithm scrapped. Diuretics should be used first-line as the cheapest and safest available drugs, they suggested.
A spokesperson for NICE said it would consider the paper and did not rule out bringing forward the planned review of its guidance.
Current NICE and British Hypertension Society guidelines recommend ACE inhibitors first-line in under-55s with calcium channel blockers or diuretics for over-55s. ß-blockers are no longer preferred first-line therapy, although they can be considered in younger patients.
But the new study could bring ß-blockers more widely into play, after finding no evidence of a differential effect in younger and older adults. It also found ‘strong support' for lowering blood pressure in elderly people, as risk reduction did not decline with age.
The meta-analysis was conducted by the international Blood Pressure Lowering Treatment Trialists' Collaboration, including researchers from the University of Oxford and Imperial College London.
Study leader Dr Fiona Turnbull, senior lecturer in medicine at the University of Sydney, said: ‘The results greatly simplify things. Lowering BP lowers risk of stroke or heart attack and, as long as effective blood pressure reduction is achieved, factors such as tolerability and cost should be bases for drug choice, not a patient's age.'
Dr John Ashcroft, a GP in Ilkestone and vascular lead for Derbyshire County PCT, said: ‘This study means you should go for the cheapest agents, with the best side-effect profiles at all ages – that is, low-dose diuretics.'
But Professor Peter Sever, a member of the British Hypertension Society's guidelines working party, questioned the age
cut-off of 65 in the meta-analysis, and said the suggestion GPs should not take a patient's age into account was ‘utterly wrong'.
Professor Bryan Williams, professor of medicine at the University of Leicester and expert adviser to NICE, said: ‘This is a meta-analysis, not a trial. It does not in any way detract from the BHS/NICE recommendations, although I suspect it has been designed to try to do so.'