Dabigatran, rivaroxaban, or apixaban versus enoxaparin for thromboprophylaxis after total hip or knee replacement: systematic review, meta-analysis, and indirect treatment comparisons

OBJECTIVE To analyse clinical outcomes with new oral anticoagulants for prophylaxis against venous thromboembolism after total hip or knee replacement. DESIGN Systematic review, meta-analysis, and indirect treatment comparisons. DATA SOURCES Medline and CENTRAL (up to April 2011), clinical trials registers, conference proceedings, and websites of regulatory agencies. STUDY SELECTION Randomised controlled trials of rivaroxaban, dabigatran, or apixaban compared with enoxaparin for prophylaxis against venous thromboembolism after total hip or knee replacement. Two investigators independently extracted data. Relative risks of symptomatic venous thromboembolism, clinically relevant bleeding, deaths, and a net clinical endpoint (composite of symptomatic venous thromboembolism, major bleeding, and death) were estimated using a random effect meta-analysis. RevMan and ITC software were used for direct and indirect comparisons, respectively. RESULTS 16 trials in 38,747 patients were included. Compared with enoxaparin, the risk of symptomatic venous thromboembolism was lower with rivaroxaban (relative risk 0.48, 95% confidence interval 0.31 to 0.75) and similar with dabigatran (0.71, 0.23 to 2.12) and apixaban (0.82, 0.41 to 1.64). Compared with enoxaparin, the relative risk of clinically relevant bleeding was higher with rivaroxaban (1.25, 1.05 to 1.49), similar with dabigatran (1.12, 0.94 to 1.35), and lower with apixaban (0.82, 0.69 to 0.98). The treatments did not differ on the net clinical endpoint in direct or indirect comparisons. CONCLUSIONS A higher efficacy of new anticoagulants was generally associated with a higher bleeding tendency. The new anticoagulants did not differ significantly for efficacy and safety.