Oral anticoagulants and cognitive impairment in patients with atrial fibrillation: A systematic review with meta-analysis and trial sequential analysis

Background: This systematic review assesses the likelihood of developing dementia and cognitive impairment in patients with atrial fibrillation (AF) receiving non-vitamin K antagonist oral anticoagulants (NOACs) as opposed to vitamin K antagonists (VKAs). Methods: We performed a systematic review with meta-analysis and trial sequential analysis (TSA), which encompassed both randomized controlled trials (RCTs) and observational studies. The objective was to assess the impact of NOACs and VKAs on the incidence of dementia in individuals diagnosed with AF. Results: Out of 1914 studies that were screened, 31 studies were included in the final analysis, which consisted of nine RCTs or their subsequent post-hoc analyses, in addition to 22 observational studies. The meta-analysis shows that NOACs were associated with a decreased probability of developing dementia of any cause [Rate Ratio (RR): 0.88; 95 % confidence interval (95 % CI): 0.82–0.94], especially in patients below the age of 75 (RR: 0.78; 95 % CI: 0.73–0.84). Consistent patterns were observed across all forms of dementia and cognitive function decline. The overall evidence indicates notable variability in the outcome with a moderate-to-low degree of certainty. The TSA suggests that the total sample size of the included trials (155,647 patients) was significantly smaller than the required information size of 784,692 patients to discern the true effect of NOAC versus VKA in terms of reducing dementia risk. Conclusion: NOACs may reduce the likelihood of developing dementia in patients with AF, particularly in those under the age of 75. This review highlights the urgent necessity for thorough research to determine the efficacy of NOACs in safeguarding cognitive health.