Abstract 4137804: Associations between falls and other serious adverse events and antihypertensive medication in individuals with dementia: An observational cohort study

Background: The balance of benefits and risks associated with lowering blood pressure levels in individuals with dementia remains controversial with a lack of evidence for possible harms associated with antihypertensive treatment (AHT). Objectives: We examined the association between AHT and serious adverse events (SAEs) in individuals with dementia compared to those without. Methods: This was a retrospective analysis using nationally representative, UK general practice population between 1998 and 2018, using data from electronic health records (Clinical Practice Research Datalink, GOLD). Individuals included were age ≥40 years and not previously prescribed AHT. Diagnosis of dementia was based on standardised clinical codes. The primary outcome was the first hospitalisation or death from a fall within 10 years of the follow-up period. Secondary outcomes were first hospitalisation or death from hypotension, syncope, and fracture. Cox regression analyses, adjusted for propensity score were used to assess the risk of SAEs. Results: In a population of 1,219,732 individuals, 23,510 had dementia. Antihypertensive medications were newly prescribed in 4,062/23,510 (17.3%) individuals with dementia and 142,385/1,196,222 (11.9%) individuals without dementia in the 12 months exposure period. In individuals with dementia, AHTs were associated with an increased risk of hospitalisation or death from falls (adjusted hazard ratio [aHR] 1.15, 95% confidence interval [CI] 1.08, 1.22), hypotension (aHR 1.51, 95%CI 1.29, 1.78), syncope (aHR 1.34, 95%CI 1.11, 1.61), but not fracture (aHR 1.05, 95%CI 0.96, 1.15). In individuals without dementia, the association between AHT and SAEs was similar, with an increased risk of hospitalisation or death from falls (aHR 1.07, 95%CI 1.05, 1.10). However, absolute risk of falls with AHT per 10,000 individuals per year was significantly higher in individuals with dementia (47, 95%CI 26, 70) compared to those without (14, 95%CI 10, 18). The absolute risks of hypotension and syncope with AHT were also higher in the individuals with dementia compared to those without. Conclusions: AHT was associated with increased risk of SAEs in individuals with and without dementia, however, the absolute risk of harm from falls was more than double in individuals with dementia. Clinicians, patients, and their carers should consider these risks before starting new antihypertensive medications, particularly in the context of dementia, although they remain small.