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 (MaxVelt)]. ASA (n = 80) and ASA + ADP patients (n = 78) revealed a prolonged clot initiation. ASA patients had decreased clot propagation (increased MaxVelt), whereas ASA + ADP patients had an inconsistent change in clot propagation (increased MaxVel and MaxVelt). 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.