Continued Use of Warfarin in Veterans with Atrial Fibrillation After Dementia Diagnosis. Issue 2 (30th December 2016)

• Record Type: Journal Article
• Authors: Orkaby, Ariela R.; Ozonoff, Al; Reisman, Joel I.; Miller, Donald R.; Zhao, Shibei; Rose, Adam J.
• Is Part Of: Journal of the American Geriatrics Society. Volume 65:Issue 2(2017:Feb.)
• Page Start: 249
• Page End: 256
• Publication Date: 2016-12-30
• Subjects: atrial fibrillation -- dementia -- warfarin; Geriatrics -- Periodicals; 618.97
• DOI: 10.1111/jgs.14573
• Languages: English
• ISSNs: 0002-8614

Abstract

Abstract : Objectives: To determine the effectiveness of warfarin in older adults with dementia. Design: Retrospective cohort study. Setting: Department of Veterans Affairs national healthcare system. Participants: Veterans aged 65 and older (73% aged ≥75, 99% male, 91% white) who had been receiving warfarin for nonvalvular atrial fibrillation for at least 6 months, were newly diagnosed with dementia in fiscal year 2007 or 2008, and were not enrolled in Medicare Advantage (n = 2, 572). Measurements: The onset of dementia was defined according to International Classification of Diseases, Ninth Revision, code. Participants were followed for up to 4 years for persistence of warfarin therapy, anticoagulation control, major hemorrhage, ischemic stroke, and all‐cause mortality. Results: The average CHADS2 score was 3.3 ± 1.3. After a diagnosis of dementia, 405 individuals (16%) persisted on warfarin therapy. Unadjusted Cox proportional hazards analysis demonstrated a protective effect of warfarin in prevention of ischemic stroke (hazard ratio (HR) = 0.64, 95% confidence interval (CI) = 0.46–0.89, P = .008), major bleeding (HR = 0.72, 95% CI = 0.55–0.94, P = .02), and all‐cause mortality (HR = 0.66, 95% CI = 0.55–0.79, P < .001). Using propensity score matching, the protective effect of continuing warfarin persisted in prevention of stroke (HR = 0.74, 95% CI = 0.54–0.996, P = .047) and mortality (HR = 0.72, 95% CI = 0.60–0.87, P < .001), with no statistically significant decrease in risk of major bleeding (HR = 0.78, 95% CI = 0.61–1.01, P = .06). Conclusion: Discontinuing warfarin after a diagnosis of dementia is associated with a significant increase in stroke and mortality.