Evaluation of empiric versus nomogram-based direct thrombin inhibitor management in patients with suspected heparin-induced thrombocytopenia.

The aim of this study was to evaluate a direct thrombin inhibitor (DTI) titration protocol in patients with suspected HIT. This observational study compared patients treated with argatroban or bivalirudin according to the University of Colorado Hospital DTI titration protocol versus a control group treated prior to protocol implementation. Protocol patients had DTI initial doses based on organ function and fixed dosage adjustments of 10, 25, or 50%. Initial doses and titrations in the control group were made per physician discretion. A total of 130 patients were enrolled: 47 in the protocol group and 83 in the control group (median age 54 years, 63% male, 78% critically ill, and 54% received argatroban). Goal aPTT was achieved with initial DTI dose in 64% of protocol patients and 46% of control patients (P = 0.07). Median (IQR) time to goal aPTT was reduced in the protocol group compared to the control group [5 hr (2-10 hr) vs. 13 hr (6-29 hr); P < 0.0001]. Median time to dose stabilization was 10 hr (6-27 hr) and 22 hr (13-40 hr) in the protocol and control groups, respectively; P < 0.0001. Median number of titrations to goal was 0 (0-1) versus 1 (0-4), respectively; P = 0.02. Median percentage of aPTT values in goal was 67% (41-100%) versus 53% (33-76%), respectively; P = 0.027. The DTI titration protocol shortened time to achieve goal aPTT, reduced time to dose stabilization, decreased the number of titrations required to achieve aPTT goal, and improved the percentage of aPTT values in goal range.