Extended-Duration Venous Thromboembolism Prophylaxis in Hospitalized Acutely Ill Medical Patients: A Review of the Evidence.

To evaluate the risks and benefits of extended-duration thromboprophylaxis (EDT) beyond hospitalization in acutely ill medical patients. PubMed was searched from inception (1946) through February 2015 for the search terms venous thrombosis/prevention and control, venous thromboembolism/prevention and control, anticoagulants, and aspirin. Relevant clinical trials evaluating pharmacologic strategies for EDT were screened for inclusion. Bibliographies of articles were extensively reviewed for additional sources. Three studies, and one additional subgroup analysis, were identified for inclusion. Enoxaparin and rivaroxaban demonstrated a significant reduction in venous thromboembolism (VTE) with EDT, but the benefit with enoxaparin was limited to the highest risk groups and women. The improved efficacy in both studies was accompanied by a ~2.5-fold increase in risk of major hemorrhage. Apixaban was unable to demonstrate a reduction of VTE and was also associated with a significant increase in bleeding. EDT should not be routinely provided to all medically ill patients. It may be considered in patients at the highest risk for VTE, but careful consideration must be used due to the increased risk of bleeding.