LI Xiu-min, SUN Shi-guang, ZHANG Wei-dong

Background  Enoxaparin is routinely used for prevention of venous thromboembolism (VTE) after total hip or knee arthroplasty. The purpose of this study was to compare the efficacy and safety of apixaban, a newly oral direct inhibitor of factor Xa versus enoxaparin.
Methods  We performed a meta-analysis of relevant randomized-controlled trials (RCTs) identified in PubMed, Cochrane Library, Embase China Biological Medical Literature database, Countries Journal full-text database, VIP database, and WanFang database. The primary efficacy outcome for our meta-analysis was all VTE and all-cause mortality. The secondary efficacy outcomes included major VTE, non-fatal pulmonary embolism, and mortality. The primary safety outcome was bleeding events, categorized as major, clinically relevant non-major, or minor events.
Results  Four RCTs, involving 14 065 patients, were included in our meta-analysis. Compared to enoxaparin, thromboprophylaxis with apixaban was associated with significantly fewer VTE and all-cause mortality (8346 patients, risk ratio (RR): 0.63, 95% CI 0.42–0.95) and similar incidence of bleeding events (major bleeding, 11 525 patients, RR 0.76, 95% CI 0.43–1.33; clinically relevant non-major bleeding, 11 525 patients, RR 0.83, 95% CI 0.69–1.01; and minor bleeding, 11 828 patients, RR 0.93, 95% CI 0.79–1.09). However, our meta-analysis revealed similar effects of apixaban with enoxaparin for thromboprophylaxis with regard to the secondary efficacy outcomes.
Conclusions  Apixaban was more effective than recommended dose of enoxaparin and had a similar safety profile for thromboprophylaxis after hip and knee arthroplasty. But more evidence, especially well designed head-to-head RCTs, is needed to confirm the superior efficacy of apixaban.