Efficacy and Safety of Non-Vitamin K Antagonist Oral Anticoagulants in Atrial Fibrillation Patients With Impaired Liver Function: A Retrospective Cohort Study.

Background Patients with impaired liver function ( ILF ) were excluded from clinical trials that investigated non-vitamin K antagonist oral anticoagulants ( NOAC s) for stroke prevention in patients with atrial fibrillation. The aim of this study was to evaluate the efficacy and safety of NOAC s in atrial fibrillation patients with ILF . Methods and Results A cohort study based on electronic medical records was conducted from 2009 to 2016 at a multicenter healthcare provider in Taiwan and included 6451 anticoagulated atrial fibrillation patients (aged 76.7±7.0 years, 52.5% male). Patients were classified into 2 subgroups: patients with normal liver function (n=5818) and patients with ILF (n=633, 9.8%). Cox regression analysis was performed to investigate the risks of thromboembolism, bleeding, and death associated with use of NOAC s and warfarin in patients with normal liver function and ILF , respectively. In patients with normal liver function, compared with warfarin therapy (n=2928), NOAC therapy (n=4048) was associated with significantly lower risks of stroke or systemic embolism (adjusted hazard ratio: 0.75; 95% confidence interval, 0.65-0.88; P<0.001) and death (adjusted hazard ratio: 0.69; 95% confidence interval, 0.60-0.80; P<0.001) with no difference in major bleeding or gastrointestinal bleeding. In patients with ILF , compared with warfarin therapy (n=394), NOAC therapy (n=342) was associated with significantly lower risk of death (adjusted hazard ratio: 0.64; 95% confidence interval, 0.49-0.83; P<0.001), but no difference in stroke or systemic embolism, major bleeding, or gastrointestinal bleeding. Conclusions In atrial fibrillation patients with ILF , NOAC therapy and warfarin therapy were associated with similar risks of stroke or systemic embolism, major bleeding, and gastrointestinal bleeding.