RECORD3 was a multicentre, phase III study designed to investigate the efficacy and safety of rivaroxaban – a novel, oral, once-daily, direct Factor Xa inhibitor – compared with subcutaneous enoxaparin for thromboprophylaxis in patients undergoing total knee arthroplasty (TKA). Patients scheduled to undergo TKA (N=2,531) were randomized to receive either rivaroxaban 10 mg once daily (initiated 6–8 hours after surgery) or enoxaparin 40 mg once daily (initiated the evening before surgery, then given 6–8 hours after surgery), and daily thereafter for 10–14 days. The primary efficacy outcome was the composite of any deep vein thrombosis (DVT; symptomatic or asymptomatic detected by mandatory, bilateral venography), non-fatal pulmonary embolism (PE) and all-cause mortality within 13–17 days after surgery. Rivaroxaban significantly reduced the incidence of the primary efficacy outcome compared with enoxaparin (9.6% vs 18.9%, respectively; p<
0.001; relative risk reduction [RRR] 49%). Rivaroxaban significantly reduced the incidence of major VTE (the composite of proximal DVT, non-fatal PE and VTE-related death) compared with enoxaparin (1.0% vs 2.6%, p=0.01; RRR 62%), and the incidence of symptomatic VTE (0.7% vs 2.0%, p=0.005; RRR 66%). The incidence of bleeding events was similar in both groups (major bleeding: 0.6% and 0.5% in the rivaroxaban and enoxaparin groups, respectively; any on-treatment bleeding: 4.9% and 4.8%, respectively; haemorrhagic wound complications [the composite of excessive wound haematoma and surgical-site bleeding]: 2.0% and 1.9%, respectively). There were no deaths or PEs in the rivaroxaban group during the treatment period, and two deaths and four PEs in the enoxaparin group. Rivaroxaban was significantly more effective than enoxaparin for the prevention of VTE after TKA, with a similar rate of bleeding. The oral, direct Factor Xa inhibitor rivaroxaban, given once daily as a fixed, unmonitored dose of 10 mg, has the potential to change clinical practice for thromboprophylaxis after TKA.
Dabigatran etexilate (Pradaxa®) is an oral anticoagulant licensed in multiple countries, Europe and Canada, for the prevention of venous thromboembolic events (VTE) in patients undergoing total hip replacement surgery (THR) or total knee replacement surgery (TKR). The label recommendation for therapy initiation of dabigatran etexilate is a half dose given 1–4 hours after surgery. If this is not possible, then dabigatran etexilate should be started the day following surgery with the full dose. In the European pivotal Phase III clinical trials, this initial dosing was delayed until the day after surgery in 14% of the cases. This prompted a post hoc study to analyze if these patients received adequate thromboprophylaxis. Pooled efficacy data of major VTE events (composite of proximal DVT, symptomatic DVT, pulmonary embolism and VTE-related death) from the two European pivotal trials (RE-MODEL;
The oral direct thrombin inhibitor dabigatran etexilate (Pradaxa®) was recently approved in Europe for the prevention of venous thromboembolism (VTE) in patients undergoing elective total knee or total hip replacement surgery. In the Phase III RE-MODEL (
Dabigatran etexilate (Pradaxa®) is an oral direct thrombin inhibitor that was recently approved in Europe and Canada for the prevention of venous thromboembolism (VTE) in patients undergoing elective total knee replacement or total hip replacement surgery. Two pivotal clinical trials, RE-MODEL (
Continuous neuraxial or deep peripheral nerve blockade used to provide postoperative analgesia after major orthopaedic surgery is associated with a risk of spinal or perineural haematoma, especially in patients concomitantly receiving anticoagulants. Limited data on the use of fondaparinux in surgical patients in whom this procedure is performed are available. The EXPERT trial was an observational international study in patients undergoing major orthopaedic surgery designed to evaluate the overall efficacy and safety of once-daily 2.5 mg fondaparinux initiated 6 to 12 hours post-operatively and administered for 4±1 weeks after surgery. A 48-hour “therapeutic window” was applied in patients in whom a neuraxial/deep peripheral indwelling catheter was placed: one of the planned doses of fondaparinux was omitted, the catheter was removed 36 hours after the previous fondaparinux dose, and the next fondaparinux dose administered 12 hours after catheter removal. The primary endpoints were symptomatic venous thromboembolism (VTE) and major bleeding 5±1 weeks after surgery. These events were validated by an independent adjudication committee. Overall, 5704 patients (mean age ± SD: 66 ± 12 years) were recruited between July 2003 and October 2004. They underwent surgery for total hip replacement (52%, n=2941), knee replacement (40%, n=2263), hip fracture (6%, n=353), or other indications (3%, n=148). Fondaparinux was given for a median of 35 (range: 1–105) days. Many operations (62%) were performed under regional anaesthesia only. A neuraxial or deep peripheral nerve block catheter was placed in 29% (n=1630) of patients. It was removed between one and two days after surgery in 43% (706/1626), and between three and six days after surgery in 57% (920/1626). Overall, the rate of symptomatic VTE was 1.0% (54/5387); it was 0.8% (13/1535) in patients with catheter and 1.1% (41/3852) in patients without catheter, giving an odds ratio of 0.79 (95% CI: 0.42 to 1.49) in favour of patients with a catheter. The upper limit of the 95% CI being below the predetermined non-inferiority margin of 1.75, the efficacy of fondaparinux in patients with a catheter was therefore not inferior to that observed in patients without a catheter. The rate of major bleeding was 0.8% (42/5382) overall, 0.5% (7/1532) in patients with catheter and 0.9% (35/3850) in patients without catheter. No spinal or perineural hematomas or nerve damage were reported. At 5±1 weeks, 23 (0.4%) patients had died. In conclusion, 2.5 mg fondaparinux given daily for 4±1 weeks after major orthopaedic surgery was both effective and safe in routine practice. This benefit-risk ratio was similar in 1630 patients with a neuraxial/ deep peripheral indwelling catheter in whom a 48-hour “therapeutic window” was applied.
Ximelagatran is an oral direct thrombin inhibitor intended for the prophylaxis and treatment of thrombo-embolic complications. Purpose: The efficacy and safety of ximelagatran, and its subcutaneous (sc) form melagatran, were evaluated in patients undergoing total hip or knee replacement (THR, TKR). Study 1 was a randomised, double-blind, controlled, dose–response study in which patients received 2-6 doses of sc melagatran (1, 1.5, 2.25, or 3 mg bid) followed by oral ximelagatran (8, 12, 18, or 24 mg bid), or sc dalteparin (5000 IU od). Melagatran treatment was initiated immediately before surgery. Study 2 was a randomized, double-blind, controlled study in which patients received 1–5 doses of sc melagatran (3 mg bid) initiated 4–12 h after surgery followed by oral ximelagatran (24 mg bid), or sc enoxaparin (40 mg od). In both studies, low-molecular-weight heparin (LMWH) was started the evening before surgery, and all treatment regimens were continued for 8–11 days. Bilateral venography was performed on the final day of treatment. Results: In Study 1, 1876 patients underwent THR (n=1270) or TKR (n=606). A significant dose-dependent reduction in venous thromboembolism (VTE) was seen with melagatran + ximelagatran for both THR (P<
0.0001) and TKR (P=0.0014). The rate of VTE was significantly lower with the highest dose of melagatran + ximelagatran (15.1%) when compared with dalteparin (28.2%) (P<
0.0001). In Study 2, 2788 patients underwent THR (n=1923) or TKR (n=865). The VTE rate was 31% in the melagatran + ximelagatran group and 27% in the enoxaparin group (P=0.053). Total bleeding volume was not significantly different between treatment groups. Conclusion: Fixed-dose sc melagatran followed by oral ximelagatran are efficacious and well tolerated for the prophylaxis of VTE following THR or TKR.