MO503
SAFETY AND EFFICACY OF ANTICOAGULATION IN PATIENTS WITH EGFR<30 ML/MIN/1.73 M2 AND ATRIAL FIBRILLATION Free

Net benefit of anticoagulation in patients with eGFR <30 ml/min/1.73 m2 and atrial fibrillation remains uncertain. The aim of this study was to evaluate the use, efficacy and safety of anticoagulation therapy in patients with eGFR<30 ml/min/1.73m² (including dialysis treated patients) and atrial fibrillation.

In a retrospective cohort study, all patients with atrial fibrillation and eGFR<30 ml/min/1.73 m² were identified in nationwide Danish registers between 2008 and 2018. Cumulative incidences of stroke and major bleeding stratified on anticoagulation treatment were computed using the Aalen-Johansen estimator. One-year risks of stroke and major bleeding were calculated with comparison of treatment vs. no treatment based on Cox regression models adjusted for age, sex and dialysis status with G-computation of one-year risks standardized to the distribution of risk factors in the sample. Major bleeding was defined as any diagnosis of bleeding leading to hospitalization.

A total of 2,452 patients with eGFR <30 ml/min/1.73 m² and de novo atrial fibrillation were identified. Mean age was 78.8 years, 51.3% were male and 20% received dialysis therapy. Anticoagulation therapy was initiated in 877 patients (35.8%), with warfarin accounting for 58.6% of all prescriptions.

Overall, one-year standardized risk of bleeding was 10.6% (95% confidence interval (CI) 8.7%-12.7%) and 8.2% (95% CI 6.9%-9.5%) in patients with and without anticoagulation, while the risks of stroke were 3.6% (95% CI 2.6%-4.5%) and 5.1% (95% CI 4.1%-6.1%), respectively.

In subgroup analyses of patients dependent vs. non-dependent on dialysis, the standardized one-year risk of bleeding was 13.3% (95% CI 9.0%-19.8%) vs. 10.4% (95% CI 8.6%-12.4%) in patients with anticoagulation and 9.0% (95% CI 6.5%-12.0%) vs. 7.8% (95% CI 6.5%-9.2%) in patients without anticoagulation. While the risk of stroke was 3.5% (95% CI 0.8%-6.7%) vs. 3.5% (95% CI 2.5%-4.9%) in patients with anticoagulation and 5.7% (95% CI 3.5%-7.8%) vs. 4.9% (95% CI 3.7% vs. 6.3%) in patients without anticoagulation. Cumulative incidences of major bleeding and stroke are shown in the figure.

Use of anticoagulation was associated with increased risk of bleeding and reduced risk of stroke in patients with eGFR<30 ml/min/1.73 m² and atrial fibrillation. Randomized controlled trials are needed to establish the benefit and harm of anticoagulation in this population.