Rivaroxaban may be associated with a reduced risk of overall bleeding, gastrointestinal bleeding, and intracranial bleeding in patients with unprovoked venous thromboembolism (VTE) compared with warfarin, according to a retrospective study published in the European Journal of Hematology. The study also found that no single bleeding subtype was significantly more frequent in patients receiving rivaroxaban.
The study authors examined the association between major bleeding risk and rivaroxaban, a direct-acting oral anticoagulant compared with warfarin, a vitamin K antagonist, in patients with unprovoked VTE treated between January 2012 and December 2016. Claims data were collected from a commercial insurance database and a Medicare supplemental database.
A total of 10,489 patients receiving rivaroxaban and 26,364 patients receiving warfarin with an unprovoked VTE were identified. All the patients had received 1 or more primary diagnosis codes for unprovoked VTE during a hospitalization or visit to an emergency department. In addition, all patients were newly initiated on rivaroxaban or warfarin within 30 days after experiencing VTE.
Primary outcomes for the study were overall major bleeding and bleeding subtypes. Duration of medication and recurrence of VTE was also assessed.
Rivaroxaban was found to significantly reduce the risk of major bleeding (hazard ratio [HR] = 0.73), gastrointestinal bleeding (HR = 0.62), and intracranial hemorrhage (HR = 0.19) compared with warfarin. Patients received rivaroxaban for a median of 107 days and warfarin for a median of 113 days. Recurrent VTE was also reduced in patients who received rivaroxaban (HR = 0.53).
The authors concluded that rivaroxaban may be associated with a lower risk of overall major bleeding when used in clinical practice. However, they cautioned that this study has significant limitations because the data were collected from claims databases.
1. Kohn CG, Bunz TJ, Beyer-Westendorf J, et al. Comparative risk of major bleeding with rivaroxaban and warfarin: population-based cohort study of unprovoked venous thromboembolism [published online October 16, 2018]. Eur J Haematol. doi: 10.1111/ejh.13185