Atrial Fibrillation Is Associated with Cognitive Impairment, All-Cause Dementia, Vascular Dementia, and Alzheimer's Disease: a Systematic Review and Meta-Analysis.

Atrial fibrillation (AF) is a risk factor for cognitive impairment and dementia in patients with stroke history. However, the association between AF and cognitive impairment in broader populations is less clear. To systematically review and quantitatively synthesize the existing evidence regarding the association of AF with cognitive impairment of any severity and etiology and dementia. Medline, Scopus, and Cochrane Central were searched in order to identify studies investigating the association between AF and cognitive impairment (or dementia) cross-sectionally and longitudinally. Studies encompassing and analyzing exclusively patients with stroke history were excluded. A random-effects model meta-analysis was conducted. Potential sources of between-study heterogeneity were investigated via subgroup and meta-regression analyses. Sensitivity analyses including only studies reporting data on stroke-free patients, vascular dementia, and Alzheimer’s disease were performed. In total, 43 studies were included. In the pooled analysis, AF was significantly associated with dementia (adjusted OR, 1.6; 95% CI, 1.3 to 2.1; I2, 31%) and the combined endpoint of cognitive impairment or dementia (pooled adjusted OR, 1.5; 95% CI, 1.4 to 1.8; I2, 34%). The results were significant, even when studies including only stroke-free patients were pooled together (unadjusted OR, 2.2; 95% CI, 1.4 to 3.5; I2, 96%), but the heterogeneity rates were high. AF was significantly associated with increased risk of both vascular (adjusted OR, 1.7; 95% CI, 1.2 to 2.3; I2, 43%) and Alzheimer’s dementia (adjusted HR, 1.4; 95% CI, 1.2 to 1.6; I2, 42%). AF increases the risk of cognitive impairment, all-cause dementia, vascular dementia, and Alzheimer’s disease. Future studies should employ interventions that may delay or even prevent cognitive decline in AF patients.