Rivaroxaban for Pulmonary Embolism in a Hemodialysis Patient With Transiently Reduced Antithrombin Activity: A Case Report

A 66-year-old woman receiving maintenance hemodialysis developed acute pulmonary embolism, bilateral deep vein thrombosis, and a right atrial thrombus. Antithrombin activity was 58% during etiologic evaluation and later recovered to 93%, suggesting transiently reduced activity rather than inherited deficiency. No unfractionated or low-molecular-weight heparin had been given before antithrombin testing or subsequently used to treat the thromboembolic event. Because heparin anticoagulation depends on antithrombin, the team considered that it might be less effective and excluded a heparin-based regimen. The patient was hemodynamically stable and declined invasive procedures. After considering argatroban and warfarin, the team initiated off-label rivaroxaban following informed discussion. Rivaroxaban was started at 10 mg in the morning plus 5 mg in the evening on nondialysis days, reduced to 7.5 mg twice daily after 1 week, and then adjusted to 10 mg in the morning plus 2.5 mg in the evening on nondialysis days. During 3 months of close clinical and laboratory follow-up, the thrombi largely resolved without major bleeding or recurrent thromboembolism. This single observation does not establish the safety, efficacy, or dosing of rivaroxaban in hemodialysis; it illustrates the need for individualized, multidisciplinary decision-making when considering rivaroxaban for pulmonary embolism in patients receiving hemodialysis.