Enhanced Recovery and Abbreviated Length of Anticoagulation for Thromboprophylaxis after primary Hip Arthroplasty

Coordinating Investigators: Prof. Stavros Konstantinides, MD, Prof. Philipp Drees, MD

EU Clinical Trial No.: 2023-507490-18-00

An increasing proportion of the population in Europe and other parts of the world suffers from hip osteoarthritis necessitating surgical joint arthroplasty. Total hip arthroplasty (THA) is associated with a high risk of venous thromboembolism, but the appropriate duration of postoperative anticoagulation remains controversial. ENABLE-Hip („Enhanced Recovery and Abbreviated Length of Anticoagulation for Thromboprophylaxis after primary Hip Arthroplasty”) is a multicentre investigator-initiated and academically sponsored prospective randomised active-control trial. Short-duration (10-day) prophylactic anticoagulation (experimental arm) will be compared to standard-duration (35-day) anticoagulation (control arm). Patients will be mobilised early, following a standardised enhanced recovery protocol. Following randomisation and an initial two-day open-label period of prophylactic anticoagulation as per local protocol, treatment with the study drug (rivaroxaban at the approved prophylactic dose of 10 mg daily) will be started and continued until 10 days after surgery. After this time, patients will be switched (in a double-blinded manner) to placebo in the experimental arm, or continue on active drug in the control arm, until a total of 35 days postoperatively. The primary outcome is acute symptomatic proximal deep vein thrombosis or symptomatic/fatal pulmonary embolism within 3 months after surgery. The study is planned to include 2,932 patients. A formal interim analysis will be performed after 3-month follow-up of the first 1,760 randomised patients. ENABLE-Hip will be the first major randomised controlled trial to test an overall reduction in the duration of post-THA thromboprophylaxis, instead of replacing one antithrombotic drug by another. It has the potential to inform future guidelines for this large patient population.