Heparin-Induced Thrombocytopenia

To the Editor: Arepally and Ortel (Aug. 24 issue)¹ review the role of bivalirudin as one of the therapeutic options in the management of heparin-induced thrombocytopenia. In Table 2 of their article, the activated clotting time is listed as a means of monitoring the anticoagulation profile of bivalirudin. There is no linear correlation between the standard activated clotting time and the plasma bivalirudin concentration.^2,3 Several studies have shown that the standard activated clotting time does not provide an accurate measurement of the anticoagulation effect of bivalirudin, especially at large doses.³⁵ However, there is a good linear relationship between . . .