Heparin-induced thrombocytopenia

To the Editor: We disagree that the study by Warkentin et al. (May 18 issue)¹ identified a difference in outcome favoring the use of low-molecular-weight heparin. Their initial study of the identical patient population found no statistically significant difference in thrombotic events, incidence of venous thrombosis, episodes of major bleeding, or red-cell–transfusion requirements between the group given standard heparin and the group given low-molecular-weight heparin.² From both studies (really the same study) one can conclude only that heparin-induced thrombocytopenia is a marker of thrombotic disease, because the authors do not demonstrate that thrombosis as a consequence of heparin-induced thrombocytopenia has.