Continuing Warfarin Protective After Diagnosis of Dementia
Findings in cohort of veterans aged 65 years or older receiving warfarin for nonvalvular atrial fibrillation
FRIDAY, Jan. 6, 2017 (HealthDay News) -- For veterans receiving warfarin for nonvalvular atrial fibrillation, continuing warfarin after a diagnosis of dementia is associated with a protective effect in prevention of stroke and mortality, according to a study published online Dec. 30 in the Journal of the American Geriatrics Society.
Ariela R. Orkaby, M.D., from the Veterans Affairs Boston Healthcare System, and colleagues conducted a retrospective cohort study involving 2,572 veterans aged 65 years and older who had been receiving warfarin for nonvalvular atrial fibrillation for six months or more and were newly diagnosed with dementia. Participants were followed for up to four years.
The researchers found that 405 individuals (16 percent) persisted on warfarin therapy after a diagnosis of dementia. Warfarin had a significant protective effect in prevention of ischemic stroke, major bleeding, and all-cause mortality (hazard ratios [HRs], 0.64 [95 percent confidence interval (CI), 0.46 to 0.89; P = 0.008], 0.72 [95 percent CI, 0.55 to 0.94; P = 0.02], and 0.66 [95 percent CI, 0.55 to 0.79; P < 0.001], respectively). The protective effect of continuing warfarin persisted in prevention of stroke and mortality in propensity-matched analyses (HRs, 0.74 [95 percent CI, 0.54 to 0.996; P = 0.047] and 0.72 [95 percent CI, 0.60 to 0.87; P < 0.001], respectively); there was no statistically significant decrease in the risk of major bleeding (HR, 0.78 [95 percent CI, 0.61 to 1.01; P = 0.06]).
"Discontinuing warfarin after a diagnosis of dementia is associated with a significant increase in stroke and mortality," the authors write.