528: COMPARING ARGATROBAN AND UNFRACTIONATED HEPARIN FOR PEDIATRIC VTE A SINGLE-CENTER STUDY

Abstract

Learning Objectives: The current standard of care for parenteral treatment of venous thromboembolism (VTE) in the acute setting is anticoagulation with unfractionated heparin. This treatment has known limitations. Direct thrombin inhibitors, such as argatroban, have been used with increasing frequency and success in adults. There is little data on the use of these agents in pediatrics. Our goal was to compare titratability of argatroban and heparin and the ability to remain within a therapeutic window in patients who received argatroban. Methods: Single center, retrospective study of all inpatients receiving argatroban for VTE between January 2010 and December 2016. We obtained dosing data for heparin and argatroban, therapeutic goals, and all PTT and anti Xa values. Titrations were identified by computer algorithm and confirmed by manual review. Primary outcomes were time to first therapeutic goal and minutes inside therapeutic window. Secondary outcomes were titrations required to reach therapeutic goal and titrations per drug run. We analyzed time to therapeutic goal with a Cox frailty Survival model adjusted for age and within subject. We used a Negative Binomial model to analyze time in therapeutic window, titrations to reach goal, and number of titrations per drug run. Results: A total of 23 patients received argatroban, 17 also received heparin in the same encounter. Median age was 126 months. There were a total of 53 drug runs (26 heparin and 27 argatroban). Median days on heparin was 2.85 (IQR: 0.77–5.06) and 2.75 for argatroban (IQR: 1.0–6.0). The Cox frailty model showed no significant effect of drug for time to therapeutic goal (HR for argatroban vs. Heparin: 1.4 with 95% C.I.: 0.7–2.8, p=0.29). There was no significant effect of drug for time in therapeutic window (p=0.82). There was no difference between heparin and argatroban in titrations during the drug run (p=0.74). In the subset of 40 runs where the therapeutic goal was reached there was no difference in the number of titrations (p=0.41). Conclusions: There was no difference between heparin and argatroban in this single center cohort for time to first therapeutic goal or total time inside therapeutic window. Choice of drug had no effect on number of titrations to reach therapeutic goal and overall number of titrations per drug run. These findings may be due to lack of controlling for potential confounders such as severity of illness and diagnosis, as well as a limited sample size.