Comparison of rivaroxaban and low molecular weight heparin in the treatment of cancer-associated venous thromboembolism: a Swedish national population-based register study.

Background: Treating cancer-associated venous thromboembolism (CAT) with anticoagulation prevents recurrent venous thromboembolism (rVTE), but increases bleeding risk. Objectives: To compare incidence of rVTE, major bleeding, and all-cause mortality for rivaroxaban versus low molecular weight heparin (LMWH) in patients with CAT. Methods: We developed a cohort study using Swedish national registers 2013–2019. Patients with CAT (venous thromboembolism within 6 months of cancer diagnosis) were included. Those with other indications or with high bleeding risk cancers were excluded (according to guidelines). Follow-up was from index-CAT until outcome, death, emigration, or end of study. Incidence rates (IR) per 1000 person-years with 95% confidence interval (CI) and propensity score overlap-weighted hazard ratios (HRs) for rivaroxaban versus LMWH were estimated. Results: We included 283 patients on rivaroxaban and 5181 on LMWH. The IR for rVTE was 68.7 (95% CI 40.0–109.9) for rivaroxaban, compared with 91.6 (95% CI 81.9–102.0) for LMWH, with adjusted HR 0.77 (95% CI 0.43–1.35). The IR for major bleeding was 23.5 (95% CI 8.6–51.1) for rivaroxaban versus 49.2 (95% CI 42.3–56.9) for LMWH, with adjusted HR 0.62 (95% CI 0.26–1.49). The IR for all-cause mortality was 146.8 (95% CI 103.9–201.5) for rivaroxaban and 565.6 (95% CI 541.8–590.2) for LMWH with adjusted HR 0.48 (95% CI 0.34–0.67). Conclusions: Rivaroxaban performed similarly to LMWH for patients with CAT for rVTE and major bleeding. An all-cause mortality benefit was observed for rivaroxaban which potentially may be attributed to residual confounding. Trial registration number: NCT05150938 (Registered 9 December 2021). Highlights: Treating cancer-associated venous thromboembolism with anticoagulation prevents recurrent VTE, but may increase the risk of bleeding. DOACs have easier administration and proven higher treatment adherence compared to LMWH. Excluding cancer with high risk of bleeding, rivaroxaban performed similarly to LMWH for patients with cancer and VTE for recurrent VTE and major bleeding. An all-cause mortality benefit was observed for rivaroxaban compared to LMWH which potentially may be attributed to residual confounding. [ABSTRACT FROM AUTHOR]