Extended Venous Thromboembolism Prophylaxis Comparing Rivaroxaban and Aspirin to Aspirin Alone Following Total Hip and Knee Arthroplasty

 

Eligibility

Inclusion Criteria:

  • Patients undergoing elective THA/TKA

Exclusion Criteria:

  • Previous documented VTE (proximal DVT or any PE)
  • Hip or lower limb fracture in the previous three months, not related to present surgery
  • Metastatic cancer
  • Life expectancy less than 6 months
  • History of major bleeding that in the judgment of the investigator precludes use of anticoagulant prophylaxis
  • History of aspirin allergy, active peptic ulcer disease or gastritis that in the judgment of investigator precludes use of aspirin
  • History of significant hepatic disease or any other condition that in the judgment of the investigator precludes the use of rivaroxaban
  • Creatinine clearance less than 15 ml per minute
  • Pre-operative platelet count less than 100 x 109 /L
  • Need for long-term anticoagulation due to a pre-existing co-morbid condition or due to the development of VTE following surgery but prior to randomization
  • Received anticoagulation post operatively
  • Bilateral THA/TKA or simultaneous hip and knee arthroplasty
  • Major surgical procedure within the previous 3 months
  • Requirement for major surgery post arthroplasty within a 90 day period
  • Chronic daily aspirin use with dose greater than 100 mg a day
  • Women of childbearing potential who are not abstinent or do not use effective contraception or are breast-feeding throughout the study drug period
  • Unwilling or unable to give consent
  • Previous participation in the EPCAT III study
  • Under 18 years of age
  • Concomitant use of drugs that are strong inhibitors of P-gp AND CYP3A4 (e.g., systemic treatment with ketoconazole, itraconazole, or ritonavir) or strong inducers of P-gp AND CYP3A4 (e.g., rifampicin, phenytoin, carbamazepine, phenobarbital, St. John’s Wort)
  • Known allergy to food dye

Contact

PI
Dr. Glen Richardson

Description

Venous thromboembolism (VTE-deep vein thrombosis and pulmonary embolism) is a common complication following major lower limb surgery. Prior to the use of antithrombotic prophylaxis, pulmonary embolism was the most common cause of death in patients undergoing total hip arthroplasty (THA) occurring in up to 1% of patients. In 2008, rivaroxaban was approved for use in Canada for VTE prophylaxis following THA and TKA. Presently, rivaroxaban is the most commonly prescribed anticoagulant by orthopedic surgeons in Canada. The EPCAT II study demonstrated that aspirin was at least as safe and effective as rivaroxaban for preventing VTE when administered for 30 days (THA) and for 9 days (TKA), in patients who had initially received a 5 day course of rivaroxaban. These results have led to intense interest in the use of aspirin prophylaxis following total hip and knee arthroplasty.

The EPCAT III study hypothesizes that VTE prophylaxis with aspirin for 35 days (THA) and 14 days (TKA) will be at least as effective at reducing the rate of symptomatic VTE complications and will be safe and more cost-effective than 5 days of rivaroxaban followed by aspirin for identical time periods.

Study Objectives

      • To determine whether aspirin is at least as effective as rivaroxaban followed by aspirin for preventing the development of symptomatic VTE complications following THA/TKA
      • To determine the safety of this regimen as determined by rates of clinically relevant bleeding complications
      • To compare the cost-effectiveness of this regimen

Sample size = 5400 

References