Coagulopathy induced in the perioperative period of cardiac surgery is multifactorial and complex. Coagulation assessment is still usually performed using standard laboratory testing. However, many of these tests were not designed to monitor coagulation in the perioperative period. Thromboelastography or rotational thromboelastometry are being increasingly used to monitor coagulopathy in the perioperative period of cardiac surgery. Both devices record the viscoelastic properties of clot formation by measuring mechanical impedance and related changes after activation of coagulation. These devices are able to rapidly assess coagulation status on whole blood, including the concentration of clotting factors, platelets, and fibrinogen, the effects of heparin, and (hyper)fibrinolysis. Our researches aimed to define the relationship between the use of viscoelastic tests, and the reduction of perioperative blood product transfusion. Although viscoelastic tests have a poor sensitivity to assess the magnitude of fibrinolysis, we designed and experimental model that increased their sensitivity.