Association of Oral Anticoagulant Type With Risk of Dementia Among Patients With Nonvalvular Atrial Fibrillation

Abstract

Background Oral anticoagulants ( OACs ) in patients with atrial fibrillation ( AF ), in addition to reducing stroke risk, could also prevent adverse cognitive outcomes. The purpose of this study was to compare the risk of dementia incidence across patients with AF initiating different OAC s. Methods and Results We identified patients with nonvalvular AF initiating OAC s in 2 US healthcare claim databases, MarketScan (2007-2015) and Optum Clinformatics (2009-2015). Dementia, comorbidities, and use of medications were defined on the basis of inpatient and outpatient claims. We performed head-to-head comparisons of warfarin, dabigatran, rivaroxaban, and apixaban in propensity score-matched cohorts. We calculated hazard ratios ( HR s) and 95% confidence intervals ( CI s) of incident dementia for each propensity score-matched cohort and meta-analyzed database-specific results. We analyzed 307 099 patients with AF from the MarketScan database and 161 346 from the Optum database, of which 6572 and 4391, respectively, had a diagnosis of incident dementia. The mean follow-up of each cohort ranged between 0.7 and 2.2 years. Patients initiating direct OACs experienced lower rates of dementia than those initiating warfarin (dabigatran: HR , 0.85; 95% CI , 0.71-1.01; rivaroxaban: HR , 0.85; 95% CI , 0.76-0.94; apixaban: HR , 0.80; 95% CI , 0.65-0.97). There were no differences in rates of dementia comparing direct OAC user groups (dabigatran versus rivaroxaban: HR , 1.02; 95% CI , 0.79-1.32; dabigatran versus apixaban: HR , 0.92; 95% CI , 0.63-1.36; apixaban versus rivaroxaban: HR , 1.01; 95% CI , 0.86-1.19). Conclusions Patients with AF initiating direct OACs experienced lower rates of incident dementia than warfarin users. No obvious benefit was observed for any particular direct OAC in relation to dementia rates.

Keywords: atrial fibrillation; dementia; direct oral anticoagulant; warfarin.

Figure 1

Flow chart of enrollees’ selection to final analysis sample. Inclusion criteria were applied to the MarketScan and Optum databases, and all the eligible enrollees were matched 1:1 on propensity score to generate 6 final head‐to‐head oral anticoagulant (OAC) comparison cohorts. AF indicates atrial fibrillation.