2026 FSA Podium and Poster Abstracts

Background: Patients with nonvalvular atrial fibrillation (AF) and advanced chronic kidney disease (CKD), including stage 4–5 CKD and end-stage renal disease (ESRD), are at high risk for both thromboembolic and bleeding complications. Randomized clinical trials evaluating direct oral anticoagulants (DOACs) have largely excluded patients with severe renal dysfunction, resulting in limited evidence to guide anticoagulation decisions in this population. Warfarin has historically been the most commonly used anticoagulant in advanced CKD, while apixaban is increasingly prescribed based on emerging observational data. However, comparative real-world data evaluating both effectiveness and safety outcomes remain limited.

Methods: We performed a retrospective cohort study using the TriNetX Global Collaborative Network, which includes electronic health record data from 168 healthcare organizations. Adult patients with nonvalvular AF (ICD-10 I48) and advanced CKD (stage 4–5 CKD or ESRD) who initiated warfarin or apixaban were identified. Patients with mechanical or bioprosthetic heart valves or rheumatic mitral stenosis were excluded. Propensity score matching (1:1) was conducted to balance baseline demographics and comorbidities, including age, sex, cardiovascular disease, hypertension, diabetes mellitus, prior cerebrovascular disease, liver disease, and CKD severity. The primary effectiveness outcome was cerebral infarction (ICD-10 I63) occurring 0–365 days after anticoagulation initiation. The primary safety outcome was intracranial hemorrhage (ICD-10 I61) occurring 0–365 days after index. One-year risks, risk differences, risk ratios, and odds ratios with 95% confidence intervals were calculated.

Results: After propensity score matching, 54,371 patients were included in each treatment cohort. At one year, cerebral infarction occurred in 2,900 patients (5.3%) receiving warfarin and 2,737 patients (5.0%) receiving apixaban. Warfarin was associated with a modest but statistically significant increase in the risk of cerebral infarction compared with apixaban (risk difference 0.3%; risk ratio 1.06; 95% CI 1.007–1.115; p = 0.026). Intracranial hemorrhage occurred in 575 patients (1.1%) in the warfarin cohort and 378 patients (0.7%) in the apixaban cohort. Warfarin was associated with a significantly higher risk of intracranial hemorrhage (risk difference 0.4%; risk ratio 1.52; 95% CI 1.34–1.73; p < 0.0001).

Conclusions: Among patients with nonvalvular atrial fibrillation and advanced chronic kidney disease, warfarin therapy was associated with a higher one-year risk of both cerebral infarction and intracranial hemorrhage compared with apixaban. These real-world findings support the use of apixaban as a potentially safer and at least non-inferior anticoagulant option in patients with severe renal dysfunction, pending confirmation from randomized clinical trials.