Oral anticoagulants in extremely high risk very elderly (>90 years) patients with Atrial Fibrillation

Abstract Background The prevalence and incidence of atrial fibrillation (AF) increases with age, resulting in a high mortality and morbidity, especially from stroke and systemic thromboembolism (SSE). Nonetheless, the elderly are often denied oral anticoagulants (OACs), especially if they are “very elderly” (age ≥90 years) and perceived to be “high risk” of bleeding, for example, those with a history of intracranial haemorrhage (ICH), gastrointestinal bleeding or chronic kidney disease. We aimed to investigate the effectiveness and safety of OAC in this “high risk” very elderly group. Methods We used the Taiwan National Insurance Database to identify “high risk” very elderly subjects taking OACs, whether warfarin or non-vitamin K antagonist OACs (NOACs), who were compared to non-OAC users for the composite clinical endpoint of “ischemic stroke, ICH, major bleeding or mortality”. Propensity score matching was used for comparisons of the treatment groups. Results We studied 7,362 subjects (48.4% males; mean age 92.5 years, SD 2.78), of which 1737 were taking NOACs, 670 warfarin and 4955 were non-OAC users. Using non-OAC users as the reference group, warfarin use in “high risk” very elderly patients was associated with a higher risk of the composite endpoint (adjusted hazard ratio [aHR] 1.163, 95% CI 1.052–1.287), while NOACs were associated with a lower risk (aHR 0.763, 0.702–0.830). After propensity matching, NOACs were associated with a lower risk of events compared to “non-OAC use” or “warfarin”, while warfarin had a similar risk compared to non-OAC use (Figure). Conclusions Warfarin was associated with a similar (after propensity matching) or higher (Cox model before matching) risk of the composite clinical outcome compared to non-OAC use. NOACs were associated with a significantly lower risk of the composite clinical outcome compared to warfarin or non-OAC use. NOACs should be considered as the preferred OAC strategy in these “high risk” very elderly AF patients. Funding Acknowledgement Type of funding source: None