Design and rationale of the non-interventional, edoxaban treatment in routiNe clinical prActice in patients with venous ThromboEmbolism in Europe (ETNA-VTE-Europe) study

Background:Venous thromboembolism (VTE, including deep vein thrombosis [DVT] and pulmonary embolism [PE])has an annual incidence rate of 104–183 per 100,000 person-years. After a VTE episode, the two-year recurrence rate isabout 17%. Consequently, effective and safe anticoagulation is paramount. Edoxaban is a direct oral anticoagulant(DOAC) approved VTE treatment. Current safety and efficacy data are derived from clinical trials, and information abouttreatment durations beyond 12 months are not available.Methods:ETNA-VTE-Europe is an 18-month prospective, single-arm, non-interventional, multinational post-authorisationsafety study. Approximately 310 sites across eight European countries (Austria,Belgium, Germany, Ireland, Italy, theNetherlands, Switzerland and the United Kingdom) will participate in the study, with the intention to represent theregional distributions of centres, healthcare settings and specialties.An estimated cohort of 2700 patients will berecruited, the only enrolment criteriabeing acute symptomatic VTE, no participation in an interventional study, andtreating physician decision to prescribe edoxaban independently from the registry. Data from patient medical recordsand/or telephone interviews will be collected at baseline, 1, 3, 6, 12 and 18 months. The primary objective is to evaluatethe18-monthrateofsymptomaticVTErecurrenceinpatientswithVTEtreatedwithedoxabanoutsideaclinicaltrial.Theco-primary objective is to evaluate the real-world rates ofbleeding and adverse drug reactions. Secondary outcomesinclude rates of other patient-relevant safety events, adherence to and discontinuation of edoxaban. Furthermore, 12-month ETNA-VTE-Europe data will be considered in the contextof those for patients receiving different anticoagulants inthe PREFER in VTE registry and Hokusai-VTE clinical trial