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Association of outcomes and anti‐Xa levels in the treatment of pediatric venous thromboembolism
Author(s) -
Fan Jennifer L.,
Roberts Laura E.,
Scheurer Michael E.,
Yee Donald L.,
Shah Mona D.,
LeeKim YoungNa J.
Publication year - 2017
Publication title -
pediatric blood and cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.116
H-Index - 105
eISSN - 1545-5017
pISSN - 1545-5009
DOI - 10.1002/pbc.26629
Subject(s) - medicine , therapeutic index , logistic regression , therapeutic effect , venous thromboembolism , venous thrombosis , thrombus , thrombosis , drug , pharmacology
Background There are few data in the pediatric population evaluating the relationship between measured anti‐Xa levels during enoxaparin therapy and thrombotic outcomes. Objective To determine whether there is a difference in outcomes in children who receive enoxaparin with mean anti‐Xa levels between 0.45 and 0.79 unit/ml (low therapeutic range) versus between 0.80 and 1.05 unit/ml (high therapeutic range) throughout their course of their treatment. Methods We retrospectively identified subjects with uncomplicated venous thromboembolism treated with enoxaparin. Results Of 69 patients with any response to therapy, 48 (70%) had mean anti‐Xa levels in the low therapeutic range and 21 (30%) had mean anti‐Xa levels in the high therapeutic range. Of 20 patients with no documented response to therapy, 13 (65%) had mean anti‐Xa levels in the low therapeutic range and 7 (35%) had mean anti‐Xa levels in the high therapeutic range. Forty‐eight (79%) of the 61 patients with low‐range mean anti‐Xa level had any response to therapy. Twenty‐one (75%) of the 28 patients with high‐range mean anti‐Xa level had any response to therapy. Chi‐square test ( P = 0.080) and logistic regression (OR = 1.23, P = 0.70) demonstrated no significant association between mean anti‐Xa range (lower vs. upper) and therapy response. Conclusions There was no statistically significant difference between low‐range versus high‐range mean anti‐Xa levels and thrombus resolution. Empiric clinical practices of targeting anti‐Xa levels in the higher therapeutic range to achieve better outcomes may not be warranted.