A comparison of danaparoid and lepirudin in heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a hypercoagulable syndrome strong ly associated with thrombosis that is usually treated with drugs that inhib it factor Xa (danaparoid) or thrombin (lepirudin). In the present study the outcome of HIT-patients treated with danaparoid or lepirudin was compared using the single or combined endpoints of new thromboembolic complications (new TECs). amputations and/or death. and major bleeding. HIT-patients trea ted with lepirudin were enrolled in two prospective trials and patients, wh o were identified in the same two laboratories during the same time period. who were not enrolled into these studies but treated with danaparoid, were assessed retrospectively according to a standardized questionnaire. 126 da naparoid (60.3% female) and 175 lepirudin treated patients (58.3% female) f ulfilled the same inclusion and exclusion criteria. In a time-to-event-anal ysis the cumulative risk of combined endpoint was higher in HIT-patients wi thout thromboembolic complication at baseline treated with danaparoid (usua lly in prophylactic dose 750 anti-factor Xa units b.i.d. or t.i.d. s.c.) as compared to lepirudin (aPTT adjusted) (P = 0.020). Whereas HIT-patients wi th TEC at baseline who were usually treated with therapeutic dose had a sim ilar outcome in both treatment groups (P = 0.913). Major bleeding occurred in 2.5% (95% CI 0.5-7.0%) of danaparoid treated patients as compared to 10. 4% (95%; CI 6.3-15.9%) of lepirudin treated patients until day 42 (P = 0.00 9). This indicates that the efficacies of therapeutic doses of danaparoid o r lepirudin in preventing death, amputation or new TEC in HIT-patients do n ot differ largely, but the risk of bleeding seems to be higher in lepirudin treated patients. The prophylactic dose of danaparoid approved in the Euro pean Union for HIT without TEC at baseline seems suboptimal. A prospective comparative trial is required to verify these preliminary conclusions.