Atrial fibrillation and dementia: not everything is clear…

Abstract

The prevalence of dementia is ever increasing, as well as the prevalence of atrial fibrillation (AF). Several studies and systematic reviews evaluated the association between AF and dementia, highlighting an increased risk for dementia (with odds ratios from 1.4 to 1.6), with robust results in patients with previous stroke. In fact, not only vascular dementia, but also Alzheimer's disease seems more frequent in patients with AF, even though the very high heterogeneity of the results does not allow for solid conclusions. One of the mechanisms by which AF can cause dementia is the presence of silent embolic cerebral infarctions, and therefore treatment with oral anticoagulants could reduce the incidence of dementia. The results of several studies and systematic reviews show that this therapy, particularly with the new oral anticoagulants, is associated with a reduction of approximately one third of dementia. Rhythm control, obtained either with pharmacological therapy or catheter ablation, is associated with a reduction of dementia impact as well. The association between AF and cognitive deficit is therefore well documented, being more evident in patients with previous stroke but also present in cohorts of patients without prior vascular events. The development of dementia in AF patients can be due to cerebral infarctions, both clinically evident or silent, as well as by microembolism, microbleeds and hypoperfusion. Oral anticoagulation, particularly with the use of new oral anticoagulants, as well as a rhythm control strategy can reduce the incidence of dementia. More recently, it has been shown that atrial cardiomyopathy is significantly associated with the incidence of dementia, also in patients with no history of AF or stroke.