Impact of direct oral anticoagulant use on mortality in very old patients with non-valvular atrial fibrillation

Background: the efficacy and safety of direct oral anticoagulants (DOACs) compared with that of warfarin in very old patients with non-valvular atrial fibrillation (NVAF) have been reported in terms of thromboembolisms and bleeding. However, the association of DOAC use and mortality in such patients remains unclear.

Objectives: this study aimed to investigate the incidence of mortality, as well as thromboembolisms and major bleeding, in very old patients with NVAF using DOACs as compared with warfarin.

Methods: we conducted a single-centre historical cohort study of consecutive patients with NVAF aged ≥80 years who used oral anticoagulants. We compared the 5-year outcomes (all-cause mortality, thromboembolism, major bleeding and intracranial haemorrhage) between the DOAC and Warfarin groups.

Results: of 1,676 patients with atrial fibrillation aged 80 years and over, 1,208 with NVAF were included. Propensity score matching provided 461 patients in each group, and the risk of all-cause mortality, thromboembolisms, major bleeding and intracranial haemorrhages was significantly lower in the DOAC group than Warfarin group (hazard ratio [95% confidence interval] for DOAC use, 0.68 [0.54-0.87], 0.31 [0.19-0.53], 0.56 [0.36-0.88], 0.23 [0.10-0.56], log-rank P = 0.002, P < 0.001, P = 0.010, P < 0.001). The mortality rate within 1 year after major bleeding was significantly lower in the DOAC group than Warfarin group (14% versus 38%, P = 0.03), however, that after a thromboembolism was similar between the two groups (33% versus 35%).

Conclusion: patients with NVAF aged ≥80 years and using DOACs had a lower mortality than those using warfarin.