Safety and effectiveness of apixaban versus warfarin for acute venous thromboembolism in patients with end‐stage kidney disease: A national cohort study

BACKGROUND: Patients with end‐stage kidney disease (ESKD) are at significantly increased risk for both thrombosis and bleeding relative to those with normal renal function. The optimal therapy of venous thromboembolism (VTE) in patients with ESKD is unknown. OBJECTIVE: To compare the safety and effectiveness of apixaban relative to warfarin in patients with ESKD and acute VTE. DESIGN, SETTING AND PARTICIPANTS: New‐user, active‐comparator retrospective United States population‐based cohort with inverse probability of treatment weighting, using the United States Renal Data System data from 2014 to 2018. We included adults with ESKD on hemodialysis or peritoneal dialysis who were newly initiated on apixaban or warfarin for an acute VTE. MAIN OUTCOME AND MEASURES: The coprimary outcomes were major bleeding, recurrent VTE, and all‐cause mortality within 6 months of anticoagulant initiation. Secondary outcomes were intracranial hemorrhage and gastrointestinal bleeding. The primary analyses were based on intent‐to‐treat defined by the first drug received and accounted for competing risks of death. Sensitivity analyses included varied follow‐up time, as‐treated analyses, and dose‐specific apixaban subgroups. RESULTS: The apixaban and warfarin cohorts included 2302 and 9263 patients, respectively. Apixaban was associated with a lower risk of major bleeding (hazard ratio [HR] 0.81, 95% confidence interval [CI]: 0.70–0.94), intracranial bleeding (HR 0.69, 95% CI 0.48–0.98), and gastrointestinal bleeding (HR 0.82, 95% CI 0.69–0.96). Recurrent VTE and all‐cause mortality were not significantly different between the groups. CONCLUSION: Apixaban was associated with a lower risk of bleeding relative to warfarin when used to treat acute VTE in patients with ESKD on dialysis.