Influence of selected antithrombotic treatment on thromboelastometric results.

Rotatory thromboelastometry (ROTEM) is used for diagnosing and monitoring bleeding patients. Some of these patients receive antithrombotic treatment, thus having an increased risk of bleeding. Only sparse knowledge exists about whether the ROTEM analysis is influenced by antithrombotic treatment. The objective of the present study was to examine if the ROTEM results are affected in patients receiving antithrombotic treatment. This prospective observational study included patients receiving either vitamin K-antagonists (VKA), aspirin (ASA) or ASA combined with an adenosine diphosphate (ADP) receptor antagonist (ASA + ADP). ROTEM analyses were performed using the standard assays EXTEM, INTEM and FIBTEM. Furthermore, haemoglobin, platelet count, International Normalized Ratio (INR), activated partial thromboplastin time, fibrinogen (functional), creatinine, estimated glomerular filtration rate, and C-reactive protein were determined. The study included 231 patients receiving antithrombotic treatment and compared the results to ROTEM previously collected data from 73 healthy subjects. The VKA (n = 73) patients had a consistently prolonged EXTEM clot initiation (p < .0001), which was significantly correlated to the INR (Spearman's r = 0.53, p < .0001). Additionally, the VKA patients had significantly reduced clot propagation [reduced maximum velocity, maximum velocity (MaxVel) and increased time to maximum velocity (MaxVel)]. ASA (n = 80) and ASA + ADP patients (n = 78) revealed a prolonged clot initiation. ASA patients had decreased clot propagation (increased MaxVel), whereas ASA + ADP patients had an inconsistent change in clot propagation (increased MaxVel and MaxVel). In conclusion, VKA treatment was revealed by the ROTEM analysis. On the contrary, ASA and ASA + ADP treatment were not consistently revealed by the analysis.