Individualized Dose of Fibrinogen Following Cardiopulmonary Bypass

Condition(s) studied

Investigational drug(s) / intervention(s)

Blood samples for PK: Samples will be taken at regular intervals to characterize the kinetics of fibrinogen evolution post-transfusion. Sampling times will be at t = 0 (before transfusion), 10 minutes, H1, H3, H6, H9, H12, D1, and D2 relative to the start of fibrinogen transfusion (measurement of fibrinogen levels and viscoelastic tests), then every two days until the end of hospitalization (measurement of fibrinogen levels only).

Study summary

Heart surgery is essential for many cardiovascular conditions, but it is a major operation with a significant mortality rate of around 4% in Europe. Among the main complications encountered postoperatively, hemorrhage occurs at a rate of around 8.2% for severe bleeding and 1.6% for massive bleeding.

Hemorrhagic complications are caused by hemostasis disorders attributable to extracorporeal circulation (ECC). Despite recent advances in material design, ECG activates hemostasis, leading to the consumption of various coagulation factors, including fibrinogen, as well as the absorption of fibrinogen by the various components of the circuit. Postoperative hypofibrinogenemia has multiple causes and is correlated with the risk of bleeding and the need for red blood cell transfusions in cardiac surgery under CPB, and therefore indirectly with mortality related to this procedure. The administration of fibrinogen concentrates is the standard treatment; however, the optimal dose to normalize fibrinogen levels and reduce bleeding is unknown.

Good practice recommendations in cardiac surgery suggest administering fibrinogen in cases of bleeding associated with fibrinogen levels below 2 g/L. However, the time required to obtain fibrinogen level results from the laboratory (approximately 1 hour) is not always compatible with the urgency of transfusion needs in these situations. Transfusion optimization strategies have been proposed using viscoelastic tests (ROTEM, Werfen, or Quantra, Stago, for example). The administration of fibrinogen guided by these tests has reduced the need for red blood cell transfusions; however, this strategy increases the cost attributable to fibrinogen because it favors its administration without individualizing the dose to be administered. To date, it is not possible to individualize the dose of fibrinogen to be administered based on baseline fibrinogen levels and kinetics. Developing such an administration strategy would allow for i) faster correction of hypofibrinogenemia and ii) a reduction in associated costs by administering the minimum effective dose.

Eligibility

Primary outcome measure(s)

• Characterize the sources of variability in plasma fibrinogen levels in response to administration of fibrinogen concentrate after cardiac surgery with cardiopulmonary bypass. — During surgery (day 0) (before transfusion then at 10min, 1 hour, 3 hours, 6 hours, 9 hours, 12 hours after transfusion) then at day 1, day 2, day 4 and day 6.
  Measurement of blood samples using the Clauss technique

Trial sites (2)

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