Association of Anticoagulant Choice on mortality in the Primary Treatment of Non-Cancer Venous Thromboembolism: Medicare 2011-2018.

Abstract

Direct oral anticoagulants (DOACs; rivaroxaban, apixaban) and warfarin are approved for venous thromboembolism (VTE) treatment. Few direct comparisons of DOACs on risk of mortality among VTE patients exist, and for patients with concomitant conditions (e.g., kidney and liver disease) clinical guidelines are unclear. We evaluated 6-month all-cause mortality by anticoagulant prescribed for primary treatment of VTE. Using Medicare 20% sample data, we created a propensity score matched analytic dataset of 47,860 beneficiaries with non-cancer incident VTE. We used Cox regression to estimate adjusted hazard ratios (HRs) of OACs with 6-month mortality, and tested interactions by liver/kidney disease. There were 3,422 deaths over 6 months of follow-up. In adjusted models, patients prescribed rivaroxaban [HR: 0.82 (95% CI: 0.76-0.90)] had lower rates of mortality versus warfarin. There was no association comparing apixaban to warfarin [HR: 0.96 (95% CI: 0.87-1.07)]. In head-to-head comparisons of apixaban versus rivaroxaban the HR was 1.14 (95% CI: 1.01-1.28)]. Findings were similar among patients with liver and kidney disease. Overall, risk of death was similar by OAC prescribed. Though it is possible residual confounding remained, there was some suggestion of lower risk with rivaroxaban than warfarin. DOACs appear safe among VTE patients with concomitant kidney or liver disease.