Utility and correlation of known anticoagulation parameters in the management of pediatric ventricular assist devices

Abstract

AIMTo assess utility and correlation of known anticoagulation parameters in the management of pediatric ventricular assist device (VAD).METHODSRetrospective study of pediatric patients supported with a Berlin EXCOR VAD at a single pediatric tertiary care center during a single year.RESULTSWe demonstrated associations between activated thromboplastin time (aPTT) and R-thromboelastography (R-TEG) values (rs = 0.65, P < 0.001) and between anti-Xa assay and R-TEG values (rs = 0.54, P < 0.001). The strongest correlation was seen between aPTT and anti-Xa assays (rs = 0.71, P < 0.001). There was also a statistically significant correlation between platelet counts and the maximum amplitude of TEG (rs = 0.71, P < 0.001). Importantly, there was no association between dose of unfractionated heparin and either measure of anticoagulation (aPTT, anti-Xa or R-TEG value).CONCLUSIONThis study suggests that while there is strong correlation between aPTT, anti-Xa assay and R-TEG values for patients requiring VAD support, there is a lack of relevant correlation between heparin dose and degree of effect. This raises concern as various guidelines continue to recommend using these parameters to titrate heparin therapy.

Effects of a single subcutaneous dose of enoxaparin on veterinary viscoelastic coagulation monitor variables in healthy cats: Double blind, placebo controlled cross‐over trial

“…While some previous studies in people demonstrated a correlation between viscoelastic testing variables and anti-Xa activity, such findings were not consistent. 16,[27][28][29] One small experimental study in healthy dogs demonstrated a strong correlation between TEG variable r-time and anti-Xa activity. 30 Anti-Xa activity is not commonly used for monitoring people receiving LMWH.…”

Measures of anticoagulation and coagulopathy in pediatric cardiac extracorporeal membrane oxygenation patients

“…Over the last two decades, TEG has been applied in various clinical scenarios such as liver transplant, trauma or pre-and post-ventricular assist device (VAD). [29][30][31][32] These publications have described in detail the utilization of TEG for detection of coagulopathy as well as for TEG guided therapies including our previous work on use of TEG during VAD therapy. 32 Only recently, TEG guided heparin therapy was tested in a pilot study in adult ECMO and showed less adjustment and lower dose needs for heparin without adverse impact.…”

“…[29][30][31][32] These publications have described in detail the utilization of TEG for detection of coagulopathy as well as for TEG guided therapies including our previous work on use of TEG during VAD therapy. 32 Only recently, TEG guided heparin therapy was tested in a pilot study in adult ECMO and showed less adjustment and lower dose needs for heparin without adverse impact. 33 A study looking at the predicting thrombotic complications in ECMO found that Anti-Xa levels and TEG R values were predictive of thrombotic events.…”

Correlation of thromboelastography with conventional coagulation testing in elderly trauma patients on pre-existing blood thinning medications

“…Only one small retrospective study exists comparing TEG and anti-Xa levels in which a moderate correlation between TEG reaction time and anti-Xa activity was demonstrated in pediatric heart failure patients. 39…”