Thrombosis Update (Aug 2021)
Comparison of percent adjusted versus predefined incremental argatroban dosing nomograms in patients with heparin induced thrombocytopenia
Abstract
Introduction: Heparin-induced thrombocytopenia (HIT) necessitates initiation of non-heparin based anticoagulation to prevent long-term sequelae. Optimal anticoagulation needs to be reached safely and rapidly. The optimal adjustment of argatroban dosing has remained unclear. Materials and methods: This retrospective cohort study at UI Health screened patients between 1/1/2011 to 3/21/2017. Patients were included if argatroban was administered for 24 h or more for suspected or confirmed HIT. The primary outcome was to compare time to reach 2 consecutive activated partial thromboplastin time within 60 to 100 s (stable therapeutic aPTT) between pre-guideline (dose incremental adjusted) and post-guideline (percent adjusted) nomograms. Secondary outcomes were to characterize safety events and analyze the effect of covariates on the primary outcome. Results: A total of 231 patients were screened, 29 patients pre-guideline and 24 patients post-guideline were included. The mean ± SD time to reach stable therapeutic aPTT was 17.3 ± 14.4 h pre-guideline and 27.4 ± 23.5 h post-guideline (p=0.08). The mean ± SD number of dose adjustments was 1.5 ± 2.2 pre-guideline and 1.7 ± post-guideline (p = 0.89). ICU admission, hepatic impairment, albumin level, total bilirubin level, weight, and starting argatroban dose did not statistically affect time to stable therapeutic aPTT. There were 3 major bleed events and 3 thrombotic events, all occurred in pre-guideline cohort. Conclusions: No statistically significant difference in time to reach therapeutic anticoagulation between dosing nomograms or in any safety or clinical outcomes was found. Less stringent, provider-driven argatroban dosing nomograms may have similar efficacy and safety to more aggressive dosing.
