Association of Oral Anticoagulant Type with Risk of Dementia among Patients with Atrial Fibrillation Open Access

Chen, Nemin (Spring 2018)

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Oral anticoagulation (OAC) 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 AF patients initiating different OACs.


We identified patients with non-valvular AF initiating OACs in two US healthcare claim databases, MarketScan (2007-2015) and Optum Clinformatics (2009-2015). Dementia, comorbidities and use of medications were defined based on 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 (HRs) and 95% confidence intervals (CIs) of incident dementia for each propensity score-matched cohort, and meta-analyzed database-specific results.


We analyzed 307,099 AF patients from the MarketScan database and 161,346 from the Optum database, of which 6,572 and 4,391 respectively had a diagnosis of incident dementia. Mean follow-up of each cohort ranged between 0.7 and 2.2 years. Patients initiating direct oral anticoagulants (DOACs) 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 DOAC user groups (dabigatran vs. rivaroxaban: HR 1.02, 95%CI 0.79, 1.32; dabigatran vs. apixaban: HR 0.92, 95%CI 0.63, 1.36; apixaban vs. rivaroxaban: HR 1.01, 95%CI 0.86, 1.19).


Patients with AF initiating DOACs experienced lower rates of incident dementia than warfarin users. No obvious benefit was observed for any particular DOAC in relation to dementia rates.

Table of Contents

Background        1

Methods             3

Study population              3

OAC use               4

Outcome             4

Covariates           4

Statistical analysis            5

Results 8

Comparison of DOACs with warfarin        9

Comparisons among dabigatran, rivaroxaban, and apixaban          10

Sensitivity and subgroup analyses             10

Assessment of confounding by indication              11

Discussion           12

Study strengths and limitations  14

Conclusions        17

Perspectives      18

References         19

Figure Legends 23

Tables   24

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