Prevention of deep vein thrombosis after hip replacement - Comparison between two low-molecular-weight heparins, tinzaparin and enoxaparin

Consecutive patients undergoing total hip replacement in 43 centres were ra ndomly assigned to receive blindly either enoxaparin (40 mg) or tinzaparin (4,500 anti-Factor IU Xa), as once daily subcutaneous injections. The first injection was administered 12 h preoperatively. Efficacy was assessed by b ilateral venography performed 12-14 days postoperatively. Efficacy and safe ty were blindly and centrally adjudicated. Among the 499 patients included, 440 had a venogram. The total incidence of DVTs was 44 (20.1%) of the 219 patients of the enoxaparin group and fs (21.7%) of the 221 patients of the tinzaparin group. The upper limit of the 80% confidence interval of the dif ference between the two treatment groups was less than 5.0%. Therefore acco rding to the protocol's specifications equivalence was shown. Proximal DVTs occurred in 10.5% of the enoxaparin group (23 patients) and in 9.5% (21 pa tients) of the tinzaparin group. No overt major bleeding was observed. One patient in the enoxaparin group developed severe thrombocytopenia and died. The LMWH tinzaparin appears clinically to be as effective and safe as enox aparin in the prophylaxis of deep vein thrombosis after total hip replaceme nt, at the doses used and under the conditions of this study.