Risk and prediction of dementia in patients with atrial fibrillation - A nationwide population-based cohort study

BackgroundAtrial fibrillation (AF) is associated with an increased risk of cognitive impairment and functional decline, and may contribute to development of dementia.ObjectivesData from a nationwide large-scale population-based cohort study are lacking. Besides, how best to predict the occurrence of incident dementia among AF subjects remains uncertain.MethodsA total of 332,665 AF subjects without dementia were identified as the study group from the “National Health Insurance Research Database” in Taiwan. For each study patient, one age- and sex-matched subject without AF and dementia was selected as the control group. The study end point was occurrence of dementia, and the usefulness of CHADS2 and CHA2DS2-VASc scores in predicting dementia was analyzed.ResultsDuring the follow-up, 29,012 AF patients experienced dementia with an annual incidence of 2.12%, higher than non-AF subjects (1.50%). Patients with AF possessed a higher risk of dementia with a hazard ratio (HR) of 1.420 after adjustments for age, gender, baseline differences and medication use. Among AF patients, the CHADS2 and CHA2DS2-VASc scores were significant predictors of dementia with an adjusted HR of 1.520 and 1.497 per 1 increment of the CHADS2 and CHA2DS2-VASc scores, respectively. The c-index for CHA2DS2-VASc in predicting dementia (0.611, 95% confidence interval [CI] = 0.608-0.614) was significantly higher than the CHADS2 score (0.589, 95% CI = 0.586-0.592) (DeLong test p < 0.001).ConclusionsIn this nationwide cohort study, AF was independently associated with a higher risk of dementia. The CHA2DS2-VASc score can be used to estimate the risk of dementia in AF patients.