Safety and Effectiveness of Direct Oral Anticoagulants vs Warfarin in People With Atrial Fibrillation and Dementia

Objective: To determine risks of embolic events, bleeding, and mortality with direct oral anticoagulants (DOACs) vs warfarin in people with atrial fibrillation (AF) and dementia. Design: New-user retrospective cohort study using The Health Improvement Network database. Setting and Participants: A population-based sample comprising people with AF and dementia prescribed DOACs or warfarin from August 2011 to September 2017. Methods: Risk of ischemic stroke (IS), ischemic stroke/transient ischemic attack/systemic embolism (IS/ TIA/SE), all-cause mortality, intracranial bleeding (ICB), gastrointestinal bleeding (GIB), and other bleeding were compared for DOACs vs warfarin using propensity score-adjusted Poisson regression. Incidence rate ratios (IRRs) and absolute risk differences (ARDs) were calculated. Results: Overall, 2399 people with AF and dementia initiated DOACs (42%) or warfarin (58%). Before propensity score adjustment, patients who initiated DOACs were older and had more comorbidities. After adjustment, DOAC initiators demonstrated similar risks of IS, TIA, or SE; IS alone; and other bleeding but reduced ICB risk (IRR 0.27, 95% CI 0.08, 0.86; ARD -5.2, 95% CI -6.5, -1.0, per 1000 personyears) compared with warfarin. Increased risk of GIB (IRR 2.11, 95% CI 1.30, 3.42; ARD 14.8, 95% CI 4.0, 32.4, per 1000 person-years) and all-cause mortality (IRR 2.06, 95% CI 1.60, 2.65; ARD 53.0, 95% CI 30.2, 82.8, per 1000 person-years) were observed in DOAC initiators compared with warfarin. Conclusions and Implications: Among people with AF and dementia, initiating treatment with DOACs compared with warfarin was associated with similar risks of IS, TIA, or SE and IS alone. DOAC-treated patients demonstrated reduced ICB risk but increased GIB and all-cause mortality risks. We cannot exclude the possible impact of residual confounding from channeling of DOACs toward older and sicker people, particularly for the outcome of all-cause mortality. Further safety data are urgently needed to confirm findings. (C) 2019 AMDA - The Society for Post-Acute and Long-Term Care Medicine.