Abstract 8684: Atrial Fibrillation is Associated with Higher Risk of Dementia and Post-Dementia Hospitalization Mortality in Individuals Without Stroke: The Atherosclerosis Risk in Communities (ARIC) Study

Background Atrial fibrillation (AF) is associated with higher risk of dementia in stroke patients. This association in patients without stroke is unclear. We sought to determine whether AF is associated with higher risk of dementia hospitalization and post-dementia hospitalization mortality in subjects without stroke in the ARIC cohort. Methods We included 15,264 subjects (age 45-64 yrs) enrolled in 1987-89, free of stroke before AF, free of stroke between AF and dementia hospitalization, and followed through 2007. AF events and dementia hospitalizations were identified from hospitalization discharge codes; AF was also identified from 4 exam ECGs. Stroke events were identified via annual phone calls, hospital record searching, and were physician-adjudicated. All-cause mortality was determined by cohort surveillance of the National Death Index and annual phone calls. We ran multivariable proportional-hazards models to assess associations between AF (time-varying exposure) and the outcomes: dementia hospitalization and post-dementia hospitalization mortality. Models were adjusted for age, sex, race, center, education, occupation, smoking, BMI, hypertension, diabetes, heart failure, and coronary heart disease. Results During follow-up (median 18.7 yrs), there were 1,496 AF cases, 572 dementia hospitalizations, and 320 post-dementia hospitalization deaths. The multivariable HR (95% CI) of dementia hospitalization associated with AF was 1.44 (1.09-1.92), p=0.01. At 15 years, 12.9% of participants with AF and 2.1% without AF were hospitalized with dementia (log-rank test, p<0.0001) (Figure). The multivariable HR (95% CI) of post-dementia hospitalization mortality associated with AF was 1.68 (1.16-2.24), p=0.006. Conclusions In persons without stroke, AF is associated with higher risk of dementia hospitalization and post-dementia hospitalization mortality. AF may increase risk of dementia via mechanisms other than cardio-embolic stroke.