Novel oral anticoagulants for venous thromboembolism prophylaxis after total hip or knee replacement: an update on rivaroxaban (xarelto).

IntroductIon In 2005, approximately 285,000 individuals underwent total hip replacement (THR) procedures, and approximately 523,000 individuals had total knee replacement (TKR) procedures in the U.S.1 As the population ages, it is estimated that by 2030 the demand for these surgeries will increase, and the numbers are expected to grow to 572,000 THR procedures and 3,480,000 TKR procedures annually.1 Venous thromboembolism (VTE), which encompasses deep vein thrombosis (DVT) and pulmonary embolism (PE), is a significant source of morbidity and mortality following THR and TKR.2 In the absence of thromboprophylaxis, the prevalence of proximal DVT after THR and TKR procedures is 18% to 36% and 5% to 22%, respectively.2 PE occurs in approximately 0.9% to 28% of patients after THR surgery and in 1.5% to 10% of patients after TKR surgery. Rates of fatal PE are estimated to be as high as 2% following these procedures.2 The American College of Chest Physicians (ACCP) and the American Academy of Orthopaedic Surgeons have produced evidence-based clinical practice guidelines for the prevention of VTE following THR or TKR procedures.3,4 The guidelines recommend the use of pharmacological agents, mechanical compressive devices, or both, for thromboprophylaxis.3,4 Recently updated ACCP guidelines recommend the routine use of traditional anticoagulants, such as low-molecular-weight heparins (LMWHs), fondaparinux (Arixtra, GlaxoSmithKline), vitamin K antagonists such as warfarin (Coumadin, BristolMyers Squibb), aspirin, or one of the newer oral anticoagulants—rivaroxaban (Xarelto, Janssen), dabigatran (Pradaxa, Boehringer Ingelheim), or apixaban (Eliquis, Pfizer/BristolMyers Squibb)—for pharmacological thromboprophylaxis after THR or TKR surgery.3 Despite the availability of clinical practice guidelines for thromboprophylaxis after hip or knee replacement surgery, data from the Global Orthopaedic Registry suggest that compliance with the guideline recommendations is poor in real-world clinical practice, particularly in the U.S.5 Failure to provide optimal thromboprophylaxis after orthopedic surgery clearly puts patients at risk of VTE and has significant cost implications for health care institutions. Since June 2011, the Centers for Medicare & Medicaid Services has required states to implement non-payment policies for provider preventable conditions, namely VTE following THR and TKR.6 The quality of patient care after replacement surgery would be improved by closer adherence to clinical practice guidelines, and ongoing quality monitoring programs may help to address this. The Surgical Care Improvement Project (SCIP) has released a series of National Hospital Quality Measures designed to improve care after surgery by significantly reducing complications.7 Two core measures apply to VTE: SCIP-VTE-1 records the number of patients who have been prescribed VTE prophylaxis, and SCIP-VTE-2 looks at the number of patients who actually receive VTE prophylaxis.7 Even with optimal prophylaxis, some patients remain at risk for VTE, because symptomatic VTE continues to occur in 1.3% to 10% of patients within the 3-month period following THR or TKR surgery.2 There is, therefore, an urgent need for improved prophylactic agents. The goal of this article is to educate clinicians, including pharmacists, nurses, and physicians, on new developments in VTE prophylaxis following THR or TKR surgery and to present study data, clinical highlights, and pharmacoeconomic analyses of the oral anticoagulant rivaroxaban. Novel Oral Anticoagulants for Venous Thromboembolism Prophylaxis After Total Hip or Knee Replacement