Direct oral anticoagulants are associated with lower risk of dementia in patients with atrial fibrillation

Background and aim: Atrial fibrillation (AF) is associated with increased risk of dementia. Whether direct oral anticoagulation (DOAC) reduce this risk compared to vitamin-K antagonist (VKA) is unclear. The aim of this study was to assess the risk of new all-cause dementia and vascular dementia in AF patients, treated with either DOAC or VKAs. Methods: Anonymized electronic medical records from the TriNetX federated research network were used. AF patients treated with DOACs within 1 month of AF diagnosis, were 1:1 propensity score-matched with those treated with a VKA. The analysis included patients who completed 5 and 10 years of follow-up and were assessed for all-cause dementia and vascular dementia. Cox proportional hazard models were used to hazard ratios (HR), respectively with 95% confidence intervals (CIs). Results: Among patients who completed 5 years of follow-up, after propensity score matching the final cohort consisted of 215,404 well-matched AF patients. All-cause dementia was diagnosed in 4,153 (3.9%) patients among those treated with DOACs and 4,150 (3.9%) among the VKA-treated patients (HR: 1.01, 95%CI: 0.96-1.05). Among patients 65-74 years old who were followed, DOAC treatment was associated with lower risk of dementia compared to VKAs (HR: 0.72; 95%CI: 0.59-0.86). Among patients who completed 10 years of followup, after propensity score matching the final cohort consisted of 19,208 well-matched AF patients. All-cause dementia was diagnosed in 314 (3.3%) patients among those treated with DOACs and 451 (4.7%) among the VKA-treated patients. DOAC treatment was associated with significantly lower risk of all-cause dementia during a follow-up period of 10 years compared to VKA treatment (HR: 0.72, 95%CI: 0.62-0.83), which remained consistent in patiens >= 65 years old. Conclusion: This propensity-score matched analysis showed that among AF patients, treatment with a DOACs for a period of 10 years was associated with lower risk of all-cause dementia and vascular dementia compared to VKA treatment, an effect which was not apparent in those treated for shorter duration. This finding requires confirmation in ongoing randomised controlled trials.