Purpose: Venous thromboembolism (VTE) after major orthopaedic surgery remains an important clinical problem. Convenient, oral antithrombotic agents that are both effective and safe could improve adherence to guidelines for VTE prophylaxis. Recently, the focus has been on the development of oral agents that target a single step in the coagulation cascade and Factor Xa is a pivotal step. Rivaroxaban is an oral, direct Factor Xa inhibitor. Four international phase III trials (the RECORD programme) were undertaken to investigate the safety and efficacy of once-daily rivaroxaban for thromboprophylaxis after major orthopaedic surgery. The results of RECORD3 showed that rivaroxaban was more effective than enoxaparin 40 mg once daily after total knee replacement (TKR), with a 48% risk reduction in VTE and all cause mortality. RECORD4 was designed to determine the efficacy and safety of 10 mg rivaroxaban od compared to 30 mg bid enoxaparin after total knee replacement (TKR).

Method: This study randomized 3148 patients to either rivaroxaban (10 mg od started 6–8 hours after surgery) or enoxaparin (30 mg bid s.c. started 12–24 hours after surgery) for 10–14 days. The primary efficacy outcome was the composite of asymptomatic deep vein thrombosis (DVT) detected by mandatory, bilateral venography and symptomatic DVT, non-fatal pulmonary embolism (PE), and all-cause mortality up to day 13±4. Secondary outcomes included major VTE (composite of proximal DVT, non-fatal PE, and VTE-related death) and symptomatic VTE. Safety outcomes included on-treatment major and non-major bleeding.

Results: Rivaroxaban provided a 31% relative risk reduction in the incidence of the primary efficacy outcome when compared to enoxaparin (6.9% vs 10.1%, respectively; p=0.012). The corresponding rates for major VTE were 1.2% and 2.0%, respectively (p=0.124) and for symptomatic VTE were 0.7% and 1.2%, respectively (p=0.187). There were no significant differences in bleeding incidence observed between rivaroxaban and enoxaparin (major bleeding: 0.7% vs 0.3%, respectively, p=0.110; clinically relevant non-major bleeding: 2.6% vs 2.0%, respectively, p=0.279).

Conclusion: Rivaroxaban 10 mg od is the first oral thromboprophylactic agent to significantly reduce the incidence of VTE after TKR compared to enoxaparin 30 mg bid, with a similar, low rate of bleeding.

Introduction: The standard length of hospital stay after total hip arthroplasty (THA) can be as short as 4 days. However, the risk of venous thromboembolism (VTE) extends beyond this period of hospitalization. A pooled analysis of the RECORD1 and RECORD2 studies evaluated the efficacy, safety, and timing of events with rivaroxaban compared with enoxaparin for the prevention of VTE after THA.

Methods: Patients (N=7,050) were randomized to receive oral rivaroxaban 10 mg once daily starting postoperatively (for 31–39 days) or subcutaneous enoxaparin 40 mg once daily starting preoperatively (for 31–39 days in RECORD1, and 10–14 days followed by placebo in RECORD2). The primary efficacy endpoint was the composite of symptomatic VTE and all-cause mortality. The safety endpoints were treatment-emergent major bleeding, major bleeding including surgical-site bleeding, major bleeding plus clinically relevant non-major (CRNM) bleeding, and any bleeding. The primary efficacy endpoint was assessed during treatment. The incidence and timing of the safety endpoints were assessed after the first dose of study medication and up to 2 days after the last dose.

Results: Rivaroxaban significantly reduced the incidence of symptomatic VTE and all-cause mortality compared with enoxaparin regimens (0.44% vs 1.01%, respectively; p=0.006), with no significant differences in major bleeding (0.2% vs 0.09%; p=0.219) or the composite of major plus CRNM bleeding (3.23% vs 2.61%; p=0.141). Of the symptomatic VTE and all-cause mortality events, 73% and 86% occurred after day 4 with the rivaroxaban and enoxaparin regimens, respectively. For the composite of major plus CRNM bleeding, 48% and 33% of events occurred after day 4 with the rivaroxaban and enoxaparin regimens, respectively.

Conclusion: Rivaroxaban significantly reduced symptomatic VTE and all-cause mortality after THA compared with the enoxaparin regimens, with no significant difference in bleeding events. Major plus CRNM bleeding was more likely to occur earlier than day 4, whereas the majority of symptomatic venous thromboembolic events occurred after day 4. These results highlight the relevance of extended duration of thromboprophylaxis after THA as most VTE events occur post-discharge.

Introduction: The risk of venous thromboembolism (VTE) remains a major concern beyond the standard period of hospitalization of about 4 days after total knee arthroplasty (TKA). A pooled analysis of the RECORD3 and RECORD4 studies evaluated the efficacy, safety, and timing of events with rivaroxaban compared with enoxaparin for the prevention of VTE after TKA.

Methods: Patients (N=5,679) were randomized to receive oral rivaroxaban 10 mg once daily starting postoperatively or subcutaneous enoxaparin 40 mg once daily starting preoperatively (European Union regimen; RECORD3) or enoxaparin 30 mg every 12 hours starting postoperatively (North American regimen; RECORD4) for 10–14 days. The primary efficacy endpoint was the composite of symptomatic VTE and all-cause mortality, and this was analyzed over the treatment period. The safety endpoints were treatment-emergent major bleeding, major bleeding including surgical-site bleeding, major bleeding plus clinically relevant non-major (CRNM) bleeding, and any bleeding. The incidence and timing of the safety endpoints were assessed after the first dose of study medication and up to 2 days after the last dose.

Results: Rivaroxaban significantly reduced symptomatic VTE and all-cause mortality compared with enoxaparin regimens (0.73% vs 1.71%, respectively; p=0.001) with no significant differences in major bleeding (0.62% vs 0.36%, p=0.185) or composite of major plus CRNM bleeding (3.13% vs 2.48%, p=0.145). The majority of venous thromboembolic events occurred after day 4 for both regimens (rivaroxaban: 70%; enoxaparin: 68%). For the composite of major plus CRNM bleeding events, 44% occurred after day 4 with rivaroxaban regimens and 38% occurred after day 4 with enoxaparin regimens.

Conclusion: Rivaroxaban significantly reduced symptomatic VTE and all-cause mortality compared with enoxaparin regimens after TKA, with no significant difference in bleeding events between regimens. Major plus CRNM bleeding was more likely to occur before day 4, whereas the majority of symptomatic venous thromboembolic events occurred after day 4. These results highlight the importance of continuing thromboprophylaxis beyond the normal time of hospital discharge for TKA.

Introduction: Four randomized, double-blind, phase III studies (RECORD1–4) investigated the oral, direct Factor Xa inhibitor rivaroxaban for the prevention of venous thromboembolism (VTE) after major orthopaedic surgery. Patients (N=12,729) were randomized to receive oral rivaroxaban 10 mg once daily or subcutaneous enoxaparin 40 mg once daily (RECORD1–3), or 30 mg twice daily (RECORD4). In RECORD1 and 2, patients undergoing total hip arthroplasty received rivaroxaban for 31–39 days. Enoxaparin was given for 31–39 days in RECORD1, 10–14 days followed by placebo in RECORD2. In RECORD3 and 4, patients undergoing total knee arthroplasty received prophylaxis for 10–14 days. After prophylaxis, all patients were followed up for a further 30–35 days. Rivaroxaban significantly reduced the incidence of the primary efficacy outcome for the individual studies (total VTE; composite of any deep vein thrombosis, non-fatal pulmonary embolism [PE] and all-cause mortality) compared with the enoxaparin regimens, with similar rates of major bleeding.

Methods: A pre-specified pooled analysis of all four trials was performed on all randomized patients who received at least one dose of double-blind study medication to evaluate the effect of rivaroxaban on the composite of symptomatic VTE and all-cause mortality (primary outcome for pooled analysis), and bleeding. This outcome was analysed at day 12±2 in the active treatment pool (enoxaparin-controlled in all studies) and in the total study duration pool (including follow-up after treatment).

Results: Rivaroxaban significantly reduced the incidence vs enoxaparin of the composite of symptomatic VTE and death (day 12±2: 0.47% vs 0.97%, respectively, p=0.001; total study duration: 0.81% vs 1.6%, respectively, p< 0.001) and the composite of PE and death (day 12±2: 0.19% vs 0.39%, respectively, p=0.049; total study duration: 0.47% vs 0.76%, respectively, p=0.039). The rates of major bleeding with the rivaroxaban and enoxaparin regimens were 0.34% and 0.21%, respectively, p=0.175 at day 12±2 and at total study duration were 0.44% and 0.27%, respectively, p=0.135. Rivaroxaban also reduced the composite of death, infarction, stroke, symptomatic VTE and major bleeding vs enoxaparin (total study duration: 1.6% vs 2.2%, respectively, p=0.006).

Conclusion: Rivaroxaban reduced the composites of major clinical outcomes compared with enoxaparin regimens, with similar rates of major bleeding, in patients undergoing major orthopaedic surgery.

Introduction: Four randomized, double-blind phase III studies (RECORD1–4) investigated the oral, direct Factor Xa inhibitor rivaroxaban for the prevention of venous thromboembolism (VTE) after elective total hip and total knee arthroplasty (THA and TKA). Patients (N=12,729) were randomized to receive oral rivaroxaban 10 mg once daily, or subcutaneous enoxaparin 40 mg once daily (RECORD1–3), or 30 mg twice daily (RECORD4). Those undergoing THA received rivaroxaban or enoxaparin for 31–39 days in RECORD1, and rivaroxaban for 31–39 days or enoxaparin for 10–14 days followed by placebo in RECORD2. In RECORD3 and 4 (TKA), prophylaxis was for 10–14 days.

Methods: A prespecified pooled analysis of all four studies evaluated the effect of rivaroxaban on the composite of symptomatic VTE and all-cause mortality, and bleeding, relative to enoxaparin. The present subgroup analysis investigated potential drug–drug interactions with concomitant non-steroidal anti-inflammatory drugs (NSAIDs) or acetylsalicylic acid (ASA) – commonly used pain medications known to affect bleeding risk. The risk of on-treatment bleeding in the total study duration pool of all four RECORD studies was investigated. These prespecified analyses focused on on-treatment, adjudicated bleeding events, any bleeding, and the composite of major bleeding and clinically relevant non-major bleeding – after the first tablet intake (rivaroxaban or matching placebo). Co-medication use was evaluated over time. Relative bleeding rates with and without co-medication were calculated separately for the rivaroxaban and enoxaparin/placebo groups. Time after surgery (day of surgery was day 1) was stratified into three periods (days 1–3, days 4–7 and day 7 up to 2 days after the last dose), based on the decreasing risk with time of a first bleeding event after surgery and because prevalence of co-medication use can vary over time. Bleeding rates were recorded for each time period over the at-risk period (the day of surgery until the last day of double-blind study medication intake +2 days or until initial event onset). The ratio of the bleeding rate for co-medication exposed vs unexposed patient-days in the rivaroxaban group was compared with the corresponding rate ratio for the enoxaparin/placebo group for bleeding events (Mantel–Haenszel methods).

Results: Concomitant use of ASA in the rivaroxaban groups showed rate ratios similar to those in the enoxaparin/placebo group (1.32 and 1.40, respectively, for any bleeding). Rate ratios were also similar with concomitant use of NSAIDs (1.22 in both groups, for any bleeding).

Conclusion: In the RECORD1–4 subanalysis, there was no indication of increased bleeding associated with the use of these co-medications in patients taking rivaroxaban, compared with enoxaparin.

Introduction: Venous thromboembolism (VTE) after major orthopaedic surgery remains an important clinical problem. Convenient, oral antithrombotic agents that are both safe and effective could improve adherence to guidelines for VTE prevention. Recently, the focus has been on the development of oral agents that target a single step in the coagulation cascade. Factor Xa is the pivotal point in the coagulation cascade, making it a particularly attractive target for anticoagulant drugs. Rivaroxaban is an oral, direct Factor Xa inhibitor. Four international phase III trials (the RECORD programme) are being undertaken to investigate the safety and efficacy of once-daily rivaroxaban for thromboprophylaxis after major orthopaedic surgery. The results of RECORD3 showed that rivaroxaban was more effective than enoxaparin 40 mg once daily after total knee replacement (TKR), with a 48% risk reduction in VTE and all cause mortality. RECORD4 is designed to compare rivaroxaban 10mg once daily with enoxaparin 30 mg every 12 hours for thromboprophylaxis following TKR.

Methods: RECORD4 is a prospective, double-blind trial in which approximately 3000 TKR patients worldwide are being studied. Patients are randomized to receive either oral rivaroxaban 10 mg (starting 6–8 hours after surgery and continued once daily), or subcutaneous enoxaparin 30 mg (given every 12 hours and starting 12–24 hours after surgery). Study medication is given for 10–14 days, and mandatory bilateral venography is undertaken the following day. The primary efficacy outcome is a composite of deep vein thrombosis (DVT; symptomatic, or detected by mandatory venography), non-fatal pulmonary embolism (PE), and all-cause mortality. The major secondary efficacy outcome is major VTE (the composite of proximal DVT, PE and VTE-related death). The primary safety outcome is major bleeding. Other safety endpoints include all bleeding events, cardiovascular events and abnormal laboratory parameters.

Results: The final results of this trial will be presented.

Conclusions: The results of this trial will provide valuable data concerning the use of rivaroxaban for thromboprophylaxis after TKR in the North American setting.

Purpose: Thromboembolic events, such as deep vein thrombosis (DVT) and pulmonary embolism (PE), are a serious risk after major orthopaedic surgery. BAY 59-7939 is a novel, oral, direct Factor Xa inhibitor in clinical development for the prevention and treatment of thromboembolic disorders. The efficacy and safety of BAY 59-7939 for thromboprophylaxis have been determined relative to enoxaparin in two clinical trials, one after elective total hip replacement surgery, and one after elective total knee replacement surgery. This pre-specified analysis combines data from two multicenter, multinational, double-blind, dose-ranging studies; the hip surgery trial was performed in Europe, and the knee surgery trial in North America.

Methods: Patients (N=1343) were randomized to oral BAY 59-7939 at 2.5, 5, 10, 20, or 30 mg twice daily (bid), or subcutaneous enoxaparin (40 mg once daily starting 12 hours before hip surgery, or 30 mg bid starting 12 hours after knee surgery), continuing until mandatory bilateral venography was performed 5–9 days after surgery. The primary efficacy endpoint was a composite of DVT, PE, and all-cause mortality. The primary safety endpoint was major, post-operative bleeding.

Results: The primary efficacy endpoint occurred in 21.6%, 22.9%, 16.1%, 24.4%, and 19.3% of patients receiving BAY 59-7939 2.5, 5, 10, 20, and 30 mg bid, respectively, and 27.8% receiving enoxaparin (n=914). No significant dose–response relationship for efficacy was observed with BAY 59-7939 (P=0.39); this was potentially due to the efficacy achieved with the lower BAY 59-7939 doses. A significant dose–response relationship was observed for major, post-operative bleeding with BAY 59-7939 (P< 0.001), which occurred in 0.9%, 1.3%, 2.1%, 3.9%, and 7.0% of patients receiving BAY 59-7939 2.5, 5, 10, 20, and 30 mg bid, respectively, and 1.7% of patients receiving enoxaparin (n=1317).

Conclusions: This analysis showed that BAY 59-7939 has a wide therapeutic window for the prevention of VTE following major orthopaedic surgery, and, at doses of 2.5–10 mg bid, has similar efficacy and safety to the enoxaparin regimens.

Funding : Commerical funding

Funding Parties : This study was sponsored by Bayer HealthCare AG