title: Extended duration rivaroxaban versus short-term enoxaparin for the prevention of venous thromboembolism after total hip arthroplasty: a double-blind, randomised controlled trial.
abstract: BACKGROUND
  The risk of venous thromboembolism is high after total hip arthroplasty and could persist after hospital discharge. Our aim was to compare the use of rivaroxaban for extended thromboprophylaxis with short-term thromboprophylaxis with enoxaparin.
  
  
  METHODS
  2509 patients scheduled to undergo elective total hip arthroplasty were randomly assigned, stratified according to centre, with a computer-generated randomisation code, to receive oral rivaroxaban 10 mg once daily for 31-39 days (with placebo injection for 10-14 days; n=1252), or enoxaparin 40 mg once daily subcutaneously for 10-14 days (with placebo tablet for 31-39 days; n=1257). The primary efficacy outcome was the composite of deep-vein thrombosis (symptomatic or asymptomatic detected by mandatory, bilateral venography), non-fatal pulmonary embolism, and all-cause mortality up to day 30-42. Analyses were done in the modified intention-to-treat population, which consisted of all patients who had received at least one dose of study medication, had undergone planned surgery, and had adequate assessment of thromboembolism. This study is registered at ClinicalTrials.gov, number NCT00332020.
  
  
  RESULTS
  The modified intention-to-treat population for the analysis of the primary efficacy outcome consisted of 864 patients in the rivaroxaban group and 869 in the enoxaparin group. The primary outcome occurred in 17 (2.0%) patients in the rivaroxaban group, compared with 81 (9.3%) in the enoxaparin group (absolute risk reduction 7.3%, 95% CI 5.2-9.4; p<0.0001). The incidence of any on-treatment bleeding was much the same in both groups (81 [6.6%] events in 1228 patients in the rivaroxaban safety population vs 68 [5.5%] of 1229 patients in the enoxaparin safety population; p=0.25).
  
  
  CONCLUSIONS
  Extended thromboprophylaxis with rivaroxaban was significantly more effective than short-term enoxaparin plus placebo for the prevention of venous thromboembolism, including symptomatic events, in patients undergoing total hip arthroplasty.
authors.affiliation: Barts and the London School of Medicine and Dentistry, London, UK. akkakkar@tri-london.ac.uk
authors.forename: Ajay K
authors.initials: AK
authors.lastname: Kakkar
authors.forename: Benjamin
authors.initials: B
authors.lastname: Brenner
authors.forename: Ola E
authors.initials: OE
authors.lastname: Dahl
authors.forename: Bengt I
authors.initials: BI
authors.lastname: Eriksson
authors.forename: Patrick
authors.initials: P
authors.lastname: Mouret
authors.forename: Jim
authors.initials: J
authors.lastname: Muntz
authors.forename: Andrea G
authors.initials: AG
authors.lastname: Soglian
authors.forename: Akos F
authors.initials: AF
authors.lastname: Pap
authors.forename: Frank
authors.initials: F
authors.lastname: Misselwitz
authors.forename: Sylvia
authors.initials: S
authors.lastname: Haas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D017984:Enoxaparin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009025:Morpholines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000069552:Rivaroxaban; D013876:Thiophenes / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D054556:Venous Thromboembolism / Q000517:prevention & control*
chemical_list: D017984:Enoxaparin; D005343:Fibrinolytic Agents; D009025:Morpholines; D013876:Thiophenes; D000069552:Rivaroxaban