Abstract 11836: Higher Burden of Supraventricular Ectopy is Independently Associated With Greater Risk of Dementia in Older Adults Without Atrial Fibrillation: The Atherosclerosis Risk in Communities Study

Abstract

Introduction: In older adults without atrial fibrillation (AF), it is unclear if higher burden of supraventricular ectopy (SVE) is associated with dementia risk independent of cardiovascular risk factors and clinically documented stroke. Hypothesis: In older adults without AF, higher burden of SVE including premature atrial contractions (PAC) and atrial tachycardias (AT) are associated with a higher risk of dementia. Methods: Among 2167 participants (mean age, 79 years, 60% female, 26% Black) without adjudicated dementia, stroke or AF, at baseline (2016-17), AT and PAC were measured over 2 weeks by an ambulatory, continuous electrocardiogram recorder (Zio XT patch, iRhythm Technologies, Inc.). We quantified burden of PACs and ATs as: 1) natural log of frequency (episodes/day) due to skewed distributions, and 2) a dichotomous frequency measure, split at the median. Additionally, we dichotomized duration of the longest AT episode at the median. Dementia was adjudicated based on cognitive assessments through 2019 using the Clinical Dementia Rating scale at study visits or by telephone cognitive interviews, informant interviews, and ongoing linkage to medical records. We calculated relative risk of incident dementia using Poisson regression with robust error variance. Results: At baseline, median Zio XT patch wear time was 13.8 days (interquartile interval 13-14 days). Over 2 years of follow-up, 66 (3.0%) participants developed dementia. Higher frequency of AT and PAC (continuous or dichotomous) were associated with a higher risk of dementia independent of incident AF, stroke, and cardiovascular risk factors (Table). Conclusions: In older adults without AF, higher burden of SVE is associated with a greater risk of dementia independent of incident AF, stroke, and cardiovascular risk factors. Future research should define underlying mechanisms and evaluate the effect of lowering SVE burden on the risk of dementia in older adults with a higher SVE burden.