Hemodynamic aspects in the association between orthostatic hypotension and cognition: a prospective cohort study

Abstract

AbstractBackgroundOrthostatic hypotension (OH) is related to an increased risk of dementia. To explore whether cerebral hypoperfusion could play a role in this relation, we assessed different OH patterns in relation to cognitive functioning and vascular brain injury in hemodynamically compromised participants of the Heart‐Brain Connection Study.MethodParticipants with carotid occlusive disease (COD) or heart failure (HF), and reference participants underwent OH measurements, neuropsychological assessment and a brain MRI at baseline and after 2 years of follow‐up. OH was defined as a drop in blood pressure upon standing of ≥ 20 mmHg systolic or ≥ 10 mmHg diastolic. We analyzed the association between OH, global cognitive functioning, white matter hyperintensity volume and lacunar infarcts with linear and logistic regression. We stratified by participant group, severity and duration of OH, chronotropic incompetence and presence of orthostatic symptoms to model different levels of hemodynamic impact.ResultWe included 348 participants (mean age 67.3±8.7 years, 121 females) of whom 192 completed 2‐year follow‐up. OH was present in 118 (33.9%) participants. Overall, prevalence of OH was not associated with cognitive function at baseline, with similar results after stratification by participant group. Still, those with OH did perform worse on cognitive assessment in case of large blood pressure drops (≥25 mmHg systolic or ≥15 mmHg diastolic; β ‐0.07, 95%CI: ‐0.13 – ‐0.02), in case of absent chronotropic incompetence (increase in heart rate ≥8 beats/min; β ‐0.06, 95%CI: ‐0.10 – ‐0.01) or when OH was accompanied by clinical symptoms (β ‐0.10, 95%CI: ‐0.18 – ‐0.01). OH patterns were not associated with change in cognition during follow‐up in the total sample. Brain imaging markers at baseline or follow‐up did not differ between participants with or without OH.ConclusionWhile more severe OH was associated with reduced cognitive function cross‐sectionally, we observed no association with cognitive decline or vascular brain injury on MRI in hemodynamically compromised individuals. These observations do not support the hypothesis that hypoperfusion is the main driver of the association between OH and dementia risk.