July 13, 2020
Study Evaluates Rivaroxaban Versus Warfarin in Obese Patients With Acute VTE
July 13, 2020—An analysis of electronic health record (EHR) data was conducted to evaluate the effectiveness and safety of rivaroxaban (Xarelto; Bayer AG and its partner Janssen Research & Development, LLC) versus warfarin for treatment and prevention of recurrent venous thromboembolism (VTE) in obese patients.
The findings were presented at the International Society on Thrombosis and Haemostasis 2020 Virtual Congress, held online July 12-14, and published online on June 25 by Olivia S. Costa, PharmD, et al online in Journal of Thrombosis and Thrombolysis. The study is funded by Janssen.
According to the abstract of the presentation, the background of the study is that rivaroxaban has demonstrated consistent drug levels and anticoagulation activity in obese patients compared with those of normal weight. However, there are limited data on the effectiveness and safety of rivaroxaban compared with warfarin in obese patients with VTE.
The investigators performed a cohort analysis using Optum de-identified EHR data from November 1, 2012, to September 30, 2018.
The study included patients with a body mass index (BMI) ≥ 30 kg/m2 who were admitted to the hospital, emergency department, or observation unit for VTE; received rivaroxaban or warfarin as their first oral anticoagulant (OAC) within 7 days after; and had ≥ 12 months of EHR activity before the acute event. Patients with evidence of OAC use at baseline were excluded.
Patients receiving rivaroxaban were 1:1 propensity score-matched to patients receiving warfarin (standard differences < 0.1 achieved for all covariates). Outcomes included recurrent VTE and major bleeding at 3, 6, and 12 months using an intent-to-treat approach. Subanalyses stratified by BMI (30-34.9, 35-39.9, and ≥ 40 kg/m2) were performed. Risk was compared using Cox regression.
The investigators identified 6,755 rivaroxaban users and 6,755 warfarin users with a BMI ≥ 30 kg/m2 who were experiencing an incident VTE.
The investigators found that rivaroxaban was associated with a reduced risk of recurrent VTE compared with warfarin at 3, 6, and 12 months. No difference was observed in major bleeding between rivaroxaban and warfarin at 3, 6, or 12 months. Additionally, subanalyses did not show a statistically significant interaction across BMI categories for either the recurrent VTE (P-interaction ≥ .43) or major bleeding (P-interaction ≥ .58) outcomes at any time point.
Among obese patients experiencing an acute VTE, rivaroxaban was associated with a significantly reduced risk of recurrent VTE versus warfarin at 3, 6, and 12 months, without impacting major bleeding, concluded the investigators in the ISTH presentation. Investigators also noted that these findings remained consistent across evaluated BMI classes.