Clinical outcomes with unfractionated heparin monitored by anti‐factor Xa vs. activated partial Thromboplastin time

Abstract

Anti‐factor Xa (anti‐Xa) monitoring of unfractionated heparin (UFH) is associated with less time to achieve therapeutic anticoagulation compared to the activated partial thromboplastin time (aPTT). However, it is unknown whether clinical outcomes differ between these methods of monitoring. The aim of this research was to compare the rate of venous thrombosis and bleeding events in patients that received UFH monitored by anti‐Xa compared to the aPTT. A retrospective review of electronic health records identified adult patients that received UFH given intravenously (IV) for ≥2 days, with either anti‐Xa or aPTT monitoring at an academic tertiary care hospital. This was a pre/post study design conducted between January 1 to December 30, 2014 (aPTT), and January 1 to December 30, 2016 (anti‐Xa). All UFH adjustments were based on institutional nomograms. The primary outcome was venous thrombosis and the secondary outcome was bleeding, both of which occurred between UFH administration and discharge from the index hospitalization. A total of 2500 patients were in the anti‐Xa group and 2847 patients aPTT group. Venous thrombosis occurred in 10.2% vs 10.8% of patients in the anti‐Xa and aPTT groups, respectively (P = .49). Bleeding occurred in 33.7% vs 33.6% of patients in the anti‐Xa and aPTT groups, respectively (P = .94). Anti‐Xa monitoring was not an independent predictor of either outcome in multivariate logistic regression analyses. Our study found no difference in clinical outcomes between anti‐Xa and aPTT‐based monitoring of UFH IV.

A Pharmacotherapy Scholars Program to Provide Intensive Training to Enhance Pharmacy Students’ Postgraduate Readiness

“…Two manuscripts were published in peer-reviewed journals and four others were either under review or in the manuscript development phase as of fall 2019. 10,11…”

Comparison of Managing Factor Xa Inhibitor to Unfractionated Heparin Transitions by aPTT Versus a Treatment Guideline Utilizing Heparin Anti-Xa Levels

“…This estimated event rate was based on literature event rates up to 10.8%. 4,12 Due to the difficulty in estimating event rates, which could be much lower than we estimated due to variability in the literature, we determined all patients meeting inclusion and exclusion criteria would be enrolled during the study period. [16][17][18] If the primary endpoint met statistical noninferiority, it would then be analyzed for superiority.…”

“…2,3 Historically, UFH infusions have been monitored using activated partial thromboplastin time (aPTT) or UFHcalibrated anti-factor Xa assay (anti-Xa). 4 The concentration-dependent effect of FXai on measured UFH-calibrated anti-Xa levels can lead to challenges in adjusting UFH infusions, particularly in the setting of recent FXai use due to residual anticoagulant effects. 2,3,[5][6][7][8] Laboratory measurement of anti-Xa to titrate UFH in these patients continues to be a clinical dilemma.…”

Antikoagulation in der Intensivmedizin

“…Ein Teil der Wirkung von UFH kann auch mittels anti-IIa-basierten Testsystemen erfasst werden, wobei hier Antithrombin den verfügbaren Reagenzien zugefügt ist. Kontrollierte Prospektivstudien für die Anwendung dieser vom Testprinzip her spezifischeren Testsysteme im UFH-Monitoring sind kaum verfügbar [ 27 ].…”