Platelet‐mapping assay for monitoring antiplatelet therapy during mechanical circulatory support in children: A retrospective observational study

Abstract

Essentials Thromboelastography (TEG)‐platelet mapping (PM) assay is used for antiplatelet‐drug monitoring.The TEG‐PM was evaluated for dypiridamole and aspirin monitoring in 4 BH‐implanted children.Some TEG‐PM tracings were atypical leading to wrong results.The TEG‐PM has to be improved for antiplatelet‐drug monitoring during ventricular assistance. IntroductionThe complex hemostatic changes associated with Berlin Heart (BH) implantation in children require a challenging antithrombotic treatment. The aim of this retrospective analysis was to evaluate the thromboelastography (TEG)‐platelet mapping (PM) assay to monitor antiplatelet therapy in children implanted with a BH.Methods TEG‐PM was performed in 4 BH‐implanted patients receiving dipyridamole and aspirin, and 9 healthy volunteers. Patients’ antiplatelet therapy was adjusted to TEG‐PM results. Light transmission aggregometry (LTA) was also available for 2 of these patients.ResultsBetween 2009 and 2014, 4 BH‐implanted patients received a dual antiplatelet therapy monitored by TEG‐PM. In 2 patients, 18 of 34 tracings were atypical, because the maximum amplitude due to fibrin never stabilized, which made difficult antiplatelet therapy adjustment as recommended by BH's guidelines. To overcome this difficulty, TEG‐PM and LTA were next performed in parallel. However, both methods led to different decisions to adjust antiplatelet therapy in 57% of the cases. In order to better understand this atypical tracing, TEG‐PM was also performed in 9 volunteers and surprisingly 3 of them had the same atypical tracing. This atypical tracing was corrected by adding apyrase, suggesting that adenosine diphosphate (ADP) participates to spontaneous platelet activation in heparinized samples. In addition, we evidenced a high variability in the responses of TEG‐PM with ADP in volunteers.ConclusionsAntiplatelet therapy monitoring in BH‐implanted children remains challenging, as TEG‐PM is sensitive to several preanalytical and analytical conditions.

Antiplatelet Effect of Ketorolac in Children After Congenital Cardiac Surgery

“…14,15 Similarly, other investigators have considered greater than 50% to 70% AA inhibition in children to be associated with full inhibitory effect by this assay. [16][17][18][19] To our knowledge, standardized reference ranges for % AA inhibition via TEG-PM in children have not been identified in the literature. 5 The TEG-PM assay for the contribution of AA is used to test ASA effectiveness.…”

Viscoelastic Testing in the Management of Adult Patients on Mechanical Circulatory Support Devices with Focus on Extracorporeal Membrane Oxygenation

“…66 67 Many publications have suggested that TPM-AA/ADP percent inhibition is unreliable. 67 68 69 70 The experience of the authors of this article is in line with the results of these studies. 71 There is a growing amount of clinical experience and scientific literature supporting the successful use of MA-AA/ADP parameters that measure residual platelet activity when stimulated with AA or ADP agonists.…”

“…The mechanism underlying this phenomenon has not been clarified. 66,67 Many publications have suggested that TPM-AA/ADP percent inhibition is unreliable. [67][68][69][70] The experience of the authors of this article is in line with the results of these studies.…”