Background: Viscoelastic tests, whole blood-based assays that allow for continuous monitoring of clot development and dissolution, are increasingly utilized in liver transplant and other surgical settings. Correlation with conventional coagulation assays among these different populations remain largely unknown.

Aims: We hypothesized that the tenuous hemostatic state of liver failure patients may alter correlations between viscoelastic test parameters and traditional coagulation assays.

Methods: We performed a retrospective review of all FIBTEM-Maximum Clot Firmness (MCF) and Clauss fibrinogen (FIBR) assays and all EXTEM-Clotting time (CT) and Prothrombin time (PT) assays performed in parallel in liver transplant and cardiac surgery populations over a 3-year period.

Results: Ninety-five and 421 instances of parallel FIBTEM-MCF/FIBR testing were identified for liver transplant and cardiac surgery patients, respectively. For both groups, there was a strong positive correlation between FIBTEM-CT and FIBR (R=0.89, p =< 0.00001 for liver transplant; R=0.86,p=< 0.00001 for cardiac surgery). Linear regression showed FIBTEM-MCF[mm] = (0.0526)Fibrinogen[mg/dL] for liver transplant patients and FIBTEM-MCF[mm] = (0.0615)Fibrinogen[mg/dL] for cardiac surgery patients. Interestingly, linear combinations of estimators analysis of the linear coefficients showed the two patient population correlations were statistically significantly different (p=0.005).
One-hundred-and-eleven and 476 instances of parallel EXTEM/PT testing were identified for liver transplants and cardiac surgery patients, respectively. In contrast to FIBTEM-MCF/FIBR, there was a lack of correlation between the EXTEM-CT and PT in both patient populations (R= 0.30 for liver transplant; R=0.32 for cardiac surgery). No discernable difference in this lack of correlation between the two patient populations could be identified.

Conclusions: Overall, these data suggest that FIBTEM-MCF correlation with Clauss fibrinogen is altered in liver transplant patients. Additional studies to assess clinical impact are needed.

« Back to ISTH 2020 Congress

ISTH Congress Abstracts - https://abstracts.isth.org/abstract/altered-fibtem-fibrinogen-correlation-in-liver-transplant-patients-relative-to-cardiac-surgery-patients/