What have we learned from real-world NOAC studies in venous thromboembolism treatment?

Venous thromboembolism (VTE) remains a substantial clinical and health-economic burden worldwide and effective anticoagulant treatment is necessary immediately after VTE is suspected to reduce short- and long-term VTE related morbidity and mortality. For decades, low molecular weight heparin (LMWH), fondaparinux and Vitamin K antagonists (VKAs) have been the standard of anticoagulant therapy for VTE patients but these treatment options had clinically relevant drawbacks and limitations. The introduction of non-VKA oral anticoagulants (NOACs) that specifically inhibit either thrombin or factor Xa have resolved many of these drawbacks because these new compounds exhibit a rapid onset and offset of action, fewer food and drug interactions and a predictable anticoagulant effect. All NOACs have successfully completed their respective phase-III trial programs consisting of many large randomized controlled trials, leading to approval for acute VTE treatment around the world. Nevertheless, their introduction into daily care practice is challenging and a careful evaluation of the effectiveness and safety of NOACs in less selected cohorts outside carefully monitored clinical trials is essential. This review introduces the different types of real-world evidence (RWE) and explores the available data for VTE treatment with NOACs, based on a literature search using the key words "venous thromboembolism" or "VTE" in combination with "NOAC", "DOAC", "apixaban", "dabigatran", "edoxaban" and "rivaroxaban" on June 30; 2017, followed by data extraction from studies that reported real-world outcome data for VTE treatment with NOACs, although available evidence is almost exclusively limited to rivaroxaban.