Efficacy of RIvaroxaban for Prevention of Venous Thromboembolism After Knee Arthroscopy

Overview

Study Objective: To assess the value of Rivaroxaban for the prevention of venous thromboembolism (VTE) after knee arthroscopy (KA) taking the placebo as standard of reference. Study Population: Patients undergoing therapeutic KA at the study Centers, irrespective of the type and duration of the procedure, will be eligible for the study. Study Design: Multicenter, randomized, double blind superiority, phase II trial comparing two arms: * (R-7d) Rivaroxaban (10 mg od os) for 7 days * (PL-7d) Placebo for 7 days. Follow-up: 3-month period after the randomization Standard of Reference:Placebo will be the standard of reference in accordance to international guidelines Study length May 2012-December 2012 Total patients number: 500 patients Primary Efficacy End-Point: Occurrence in the 3-month period after the randomization of at least one of the following events, objectively proven (by means of CCDU; multi-slice chest TC-angio; autopsy, if necessary, or clinical ground): * All-cause mortality * Symptomatic VTE * Asymptomatic proximal DVT Secondary Efficacy End-point: • Combined incidence of all DVT plus symptomatic PE Primary Safety End-point: Incidence of major bleedings. Secondary Safety End-point: Overall incidence of bleeding

The treatments will be administered postoperatively (1st dose 8-10 hours after procedure), for prevention of venous thromboembolism after KA. A bilateral whole-leg colour-coded Doppler ultrasonography (CCDU) is scheduled for all patients at 7 (+1) days of follow-up; additionally, CCDU was due if the patients developed symptoms or signs suggestive of venous thromboembolism earlier. Statistical \& Analytical Plan and Methodology: In the absence of prophylaxis the incidence of venous thromboembolism (primary efficacy end-point) after KA, as assessed by CCDU, is about 8.0% (combining weighted results of various paper). Prophylaxis with low-molecular weight heparins assures approximately a 60-70% relative risk reduction in this setting. Based on the findings of published trials investigating the efficacy of Rivaroxaban for prevention of venous thromboembolism after elective hip and knee surgery, when using a low-molecular-weight heparin as comparator, investigators can speculate that Rivaroxaban will further reduce this incidence (at least 1.2%).