Background: It remains unclear whether oral anticoagulation (OAC) can prevent dementia or cognitive impairment (CI) in patients with atrial fibrillation (AF).Objective: To investigate the risk of dementia/CI among AF patients with and without OAC treatment.
Methods:We conducted a retrospective cohort study using UK primary care data (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016)(2017). Participants with newly diagnosed AF without a history of dementia/CI were identified. Inverse probability of treatment weights based on propensity-scores and Cox regression were used to compare the dementia outcomes.Results: Among 84,521 patients with AF, 35,245 patients were on OAC treatment, 49,276 received no OAC treatment and of these, 29,282 patients were on antiplatelets. Over a mean follow-up of 5.9 years, 5,295 patients developed dementia/CI. OAC treatment was associated with a lower risk of dementia/CI compared to no OAC treatment (hazard ratio (HR) 0.90, 95% confidence interval (CI), 0.85-0.95, p<0.001) or antiplatelets (HR=0.84, 95% CI=0.79-0.90, p<0.001). No significant difference in dementia risk was observed for direct oral anticoagulants (DOACs) versus warfarin (HR 0.89, 95% CI, 0.70-1.14, p=0.373), whereas dual therapy (OAC plus an antiplatelet agent) was associated with a higher risk of dementia/CI compared with no treatment (HR 1.17, 95% CI, 1.05-1.31), p=0.006).
Conclusion:OAC use was associated with a lower risk of dementia/CI compared to non-OAC and antiplatelet treatment among AF patients. The evidence for DOAC on cognitive function is insufficient and further studies including randomized clinical trials are warranted.