Thrombus

TEG® haemostasis system displays the new thrombus generation velocity curve

The rate and amount of thrombin generation is thought to be predictive of thrombosis or hemorrhage. The TEG® hemostasis system now provides the thrombus generation velocity curve - the first derivative of the standard TEG waveform.

The first derivative measures the rate of change and provides three new parameters of thrombus generation:

• time to maximum rate of thrombus generation (TMRTG)
• maximum rate of thrombus generation (MRTG)
• total thrombus generated (TG)

Along with the thrombus parameters, the coinciding lysis parameters are generated as well:

• time to maximum rate of lysis (TMRL)
• maximum rate of lysis (MRL)
• total lysis (TL)

Rivard et al* show in their paper the rate of thrombin generation as measured by the thrombin-antithrombin (TAT) method was compared to the TEG® thrombus generation parameter (TG). The results were highly correlated (r=.94), as shown below.

The figure below displays a series of TEG® waveforms along with the corresponding velocity curves. Increasing doses of tPA are added, resulting in increasing lysis. Note the change in shape of the lysis velocity curve (below the x axis) as the amount of tPA-and lysis-increases.

Thrombin generation information, on its own, however, is not sufficient to provide a complete picture of coagulation, since it does not take into account the contribution of fibrinogen level or cellular elements such as platelets. However, thrombus generation completes that picture, since it measures the entire process and incorporates the combination of thrombin generation along with the cell based haemostasis model. By measuring the net effect of all the hemostatic factors, the TEG® system delivers the most meaningful assessment of haemostasis as well as provides the additional TEG® parameters as a close proxy for the assessment of thrombin generation.