Lower systolic blood pressures with antihypertensive treatment have been linked to increased rates of all-cause mortality and accelerated cognitive decline among patients aged 85 and over.
Researchers from Switzerland and the Netherlands investigated the link between low blood pressure and patient outcomes in those taking antihypertensive treatments, compared with those who are not.
Their small study found that for patients prescribed antihypertensive therapy, all-cause mortality and rate of cognitive decline significantly increased with decreasing systolic blood pressure.
The paper, published in University of Oxford’s Age and Ageing, analysed data from a cohort study with a five-year follow-up, carried out in Leiden, the Netherlands.
In total, the team investigated data from 570 individuals aged 85 and over, of which 249 (43.7%) were prescribed antihypertensive therapy at baseline.
Participants prescribed and not prescribed antihypertensive therapy were similar in all other aspects except for a higher prevalence of CVD in those prescribed antihypertensives.
Researchers found that those prescribed antihypertensive therapy with a systolic blood pressure above 170 mmHg had the lowest risk of all-cause mortality, while those below 140 mmHg had the highest risk.
They also noted that those prescribed antihypertensives showed a faster rate of decline in the mental state examination as blood pressure decreased, despite the rate not being significantly faster for the non-medicated patients.
The paper said: ‘In this population-based cohort of individuals aged 85 years with a five year follow-up, we found lower systolic blood pressure was associated with higher all-cause mortality and faster annual cognitive decline in participants prescribed antihypertensive therapy.’
The authors called the findings ‘concerning’ and said: ‘For clinicians, this study raises the question of what the optimal target blood pressure level is for 85-year-old frail patients.’
NICE currently sets a higher target blood pressure for patients aged 80 and over (below 150/90 mmHg) who are treated for hypertension, when compared with those under 80 (below 140/90 mmHg).