A critical appraisal of bleeding events reported in venous thromboembolism prevention trials of patients undergoing hip and knee arthroplasty.

Four famous key opinion leaders in the field of venous thromboembolism (VTE) prevention have performed a critical appraisal of bleeding events reported in VTE prophylaxis trials of patients undergoing hip and knee arthroplasty. They have included 16 phase III trials published between 2001 and 2010 involving 41,265 patients comparing one of five new anticoagulants (fondaparinux, ximelagatran, dabigatran, rivaroxaban and apixaban) with a common comparator, enoxaparin.

They elegantly confirm what was already well known by experts and regulatory authorities: major bleeding rates in patients treated with enoxaparin range from 0.1% to 3.1% in hip arthroplasty trials and from 0.2% to 1.4% in knee arthroplasty trials, depending of the initial criteria. In studies that excluded surgical-site bleeding from the definition, major bleeding rates are about 10-fold lower than in those which included surgical-site bleeding.

The appraisal of bleeding in surgery should now undergo an international standardization process in order to homogeneize the interpretation of the data and, for sure, to prevent any temptation of companies to downplay the side effects of new anticoagulant treatments.

– Charles-Marc Samama