Majed S Al Yami, Sawsan Kurdi, Ivo Abraham

Standard-duration (7-10 days) thromboprophylaxis with low molecular weight heparin, low dose unfractionated heparin, or fondaparinux in hospitalized medically ill patients is associated with ~50% reduction in venous thromboembolism (VTE) risk. However, these patients remain at high risk for VTE post-discharge. The direct oral anticoagulants (DOACs) apixaban, rivaroxaban and betrixaban have been evaluated for extended-duration (30-42 days) thromboprophylaxis in this population. We review the efficacy and safety results from the 3 pivotal trials of extended-duration DOAC thromboprophylaxis in medically ill patients. We performed a meta-analysis of these pivotal trials focusing on 6 VTE (efficacy) and three bleeding outcomes (safety). These results were integrated into a quantitative risk/benefit assessment. The trials evaluating extended-duration DOAC thromboprophylaxis in medically ill patients failed to establish clear efficacy and/or safety signals for each agent. Our meta-analysis shows that, as a class, DOACs have selective and partial extended-duration prophylactic activity in preventing VTE events. However, this is associated with a marked increase in the risk of various bleeding events. The risk/benefit analyses fail to show a consistent net clinical benefit of extended-duration DOAC prophylaxis in medically ill patients. At this time, the evidence of safe and effective extended-duration thromboprophylaxis with DOACs in this population is inconclusive.