Whole blood thrombin generation test- a clinical validation

Rationale: The Calibrated Automated Thrombogram (CAT) assay is nowadays a very helpful tool to measure thrombin generation (TG) in the field of thrombosis and haemostasis research. Unfortunately up to now, it was only possible to perform this assay in platelet rich and poor plasma, but not in whole blood due to technical issues. We were able to overcome these problems and to adapt the CAT assay to make it able of measuring TG in a small volume of whole blood. The advantages are that whole blood is more physiological than plasma and that it can be used directly, reducing not only the time to perform the assay, but also the experimental errors that can occur.

Objective: Our primary objective is to validate our newly developed whole blood TG assay. In order to do this we want to compare and correlate the outcome of the TG assay in whole blood with TG in plasma, and also with the ROTEM, the scanning electron microscopy (SEM) and the routine coagulation tests that are performed in the hospital. Our secondary objective is to compare the results from all tests before and after transfusion of blood products and/or factor concentrates to check whether the improvement in the haemostatic function of the patient can also be detected with our newly developed whole blood TG assay.

Study design: This is a observational, comparative study between the results of the routine coagulation tests that are performed in the hospital, the ROTEM results, the SEM analysis, the results from TG in plasma with our newly developed TG assay in whole blood.

Study population: Patients above the age of 18 that are suffering from a bleeding and are transfused with blood products and/or factor concentrates during/after major surgery.

Main study parameters/endpoints: We are going to compare and correlate all the TG parameters (peak height, endogenous thrombin potential, lagtime, time-to-peak, velocity index) in plasma and whole blood with the SEM pictures (density and thickness of the fibrin network), ROTEM and the routine coagulation tests of the hospital (activated partial thromboplastin time, prothrombin time, INR, fibrinogen concentration, haematocrit, platelet count).

Whole blood thrombin generation generates reliable results which are comparable to plasma thrombin generation.

Samples are taken before and after transfusion.

Patients with controlled bleeding due to non cardiac surgery will receive standard treatment with blood products according to local protocols.