Background
The net benefit of oral anticoagulation (OAC) with vitamin K antagonists or direct oral anticoagulants in patients with advanced chronic kidney disease and atrial fibrillation remains uncertain.

Objectives
We examined the use, efficacy, and safety of OAC in patients with estimated glomerular filtration rate (eGFR) of <30 mL/min/1.73 m2 (including dialysis-treated patients) and atrial fibrillation.

Methods
In a retrospective cohort study, patients diagnosed with atrial fibrillation and eGFR of <30 mL/min/1.73 m2 were identified in national Danish registers between 2010 and 2022. Initiation of OAC was identified based on redemption of a relevant prescription. One-year risks of thromboembolic event, major bleeding, and death associated with OAC and no treatment were computed and standardized to the distribution of risk factors in the sample based on hazards determined in multiple Cox regression models adjusted for age and sex.

Results
A total of 3208 patients were included (mean age 80 years, 52.8% males, 20.9% chronic dialysis). OAC was initiated in 1375 (42.9%) patients, of whom 48.1% were vitamin K antagonists and 51.9% were direct oral anticoagulants. One-year risks in nontreated and anticoagulated patients were 4.8% (95% CI, 3.8%-5.7%) and 3.6% (95% CI, 2.8%-4.6%; P = .028) for thromboembolic event, 7.6% (95% CI, 6.6%-8.7%) and 10.5% (95% CI, 9.3%-12.1%; P < .001) for major bleeding, and 36.3% (95% CI, 34.2%-38.3%) and 29.6% (95% CI, 27.6%-31.6%; P < .001) for death, respectively.

Conclusion
In a retrospective study on patients with advanced chronic kidney disease and atrial fibrillation, OAC was associated with overall decreased 1-year risk of thromboembolic event and death offset by increased 1-year risk of major bleeding.