Can frailty inform the management of hypertension in older people?

Background

Hypertension increases the risk of cardiovascular disease. Whilst blood pressure (BP) lowering can reduce this risk, it can also cause adverse effects. This PhD study uses mixed methods to explore the utility of frailty to identify older people for whom the association of BP and outcomes is different.

Methods

Meta-analysis summarised observational studies to date. A retrospective cohort study used linked electronic health records from the Welsh Secure Anonymised Information Linkage (SAIL) databank. Frailty was measured using the electronic frailty index. Time to event analysis measured first ever major adverse cardiovascular event (MACE), all-cause mortality and injurious falls. Narrative interviews explored the perspectives of ten older people on the utility of frailty in managing hypertension on their terms.

Results

Meta-analysis identified that all-cause mortality was lower for older people who were not frail with systolic BP < 140 mm Hg compared to > 140 mm Hg, but there was no association in the context of frailty. In a population of 145,598 people with hypertension over the age of 65, compared to participants who were fit, people with frailty were associated with significantly higher MACE events despite adjustment for known cardiovascular risk factors (increased risk of 38% in mild frailty, 84% in moderate frailty, 117% in severe frailty). Frailty did not modify the association of BP and outcomes, but frailty did modify the association of BP-lowering medication and outcomes. Narrative interviews explored ways in which frailty could guide hypertension management towards what matters most to the individual.

Discussion

Findings provide evidence that frailty can usefully identify older people with increased risk of cardiovascular and non-cardiovascular outcomes in the context of hypertension management and suggest that the modifying effect of frailty in this context is in the degree to which someone sustains benefit or suffers adverse effects of BP-lowering treatment.