Comparison of percent adjusted versus predefined incremental argatroban dosing nomograms in patients with heparin induced thrombocytopenia

Abstract

IntroductionHeparin-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 methodsThis 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. ResultsA 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. ConclusionsNo 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.