Impact of Chemotherapy and Anticancer Agent Type on 30-Day All-Cause In-Hospital Mortality of Venous Thromboembolism Patients With Cancer in Japan.

Background: To contribute to the treatment and management of venous thromboembolism (VTE) patients with cancer, we used data from the Japanese Registry of All Cardiac and Vascular Diseases and the Diagnosis Procedure Combination database to clarify the impact of chemotherapy on 30-day all-cause in-hospital mortality. Annual changes in oral anticoagulant use were also evaluated. Methods and Results: We identified 106,404 VTE patients who were hospitalized for the management of VTE between 2012 and 2021. The primary outcome was all-cause in-hospital mortality within 30 days after admission for VTE. After adjusting for covariates using propensity score (PS) matching, outcomes were compared between patients with and without chemotherapy. In the PS-matched cohort, subgroup analyses estimated the association between specific anticancer agents or hormone therapy and 30-day all-cause mortality. Mortality was significantly lower in the group with than without chemotherapy group (odds ratio 0.46; P<0.001). However, the analysis revealed no significant association between any anticancer agent or therapy and 30-day mortality. Warfarin use decreased markedly from 100% in 2012 to 7% in 2021, whereas the use of oral direct Factor Xa inhibitors increased significantly (P for trend <0.001). Conclusions: In this study, 30-day mortality was lower in the group with than without chemotherapy group. Among VTE patients with cancer, direct Factor Xa inhibitors appear to be preferred over warfarin due to bleeding risk.