Risk of major bleeding in elderly users of non-vitamin K antagonist Oral anticoagulants according to advanced age

초록

Background: Recently, use of non-vitamin K antagonist oral anticoagulants (NOAC) are increasing worldwide. However, evidence on the bleeding risk associated with increasing age among elderly NOAC users have been lacking. Objectives: We aimed to investigate risk of major bleeding in elderly NOAC users in different age groups. Methods: We performed a case-crossover study using Korea Insurance Review and Assessment Service-Aged Patient Sample database during January 1, 2016 to December 31, 2016. Aged patients with hemorrhagic events using NOAC were included. Major bleeding events were defined as gastrointestinal, cerebrovascular, or other bleedings. We defined the case period as 1 to 30 days and the control period as 60 to 90 days, respectively, before the date of hemorrhagic event. We categorized aged patients into 3 groups (65–74, 75–84, and 85 or older). Odds Ratios (ORs) with 95% confidence intervals (CIs) were calculated by conditional logistic regression. Results: A total of 8,042 patient with bleeding were studied, with means age of 75.5 (±6.2) years, of whom 4,601 (57.21%) were female. The number of patients using dabigatran, rivaroxaban, apixaban, and edoxaban was 1,570 (19.5%), 4,758 (59.2%) 1,773 (22.0%), and 685 (8.5%). The OR of bleeding associated with NOAC use was 2.85 (95%, CI 2.50–3.20). The OR of major bleeding in each age groups was 2.86 (95% CI, 2.38–3.42) for 65–74 years, 2.79 (95% CI, 2.32–3.34) for 75–84 years, and 3.19 (95% CI, 2.02–4.96) for 85 years or older. Conclusions: Major bleeding events needs to be carefully monitored in elderly patients using NOAC, especially in patients aged 85 years or older. Additional factors including diseases and NOAC dose need to be further investigated.