Heparin-induced effects of prothrombin complex concentrates in thromboelastometry

Area of Science:

• Hematology
• Pharmacology

Background:

• Prothrombin complex concentrates (PCC) are used for coagulation factor deficiency and their use in reversing new oral anticoagulants is debated.
• PCC preparations often contain heparin to prevent thromboembolic events.
• Previous in vitro studies suggested a heparin effect of PCCs at appropriate concentrations.

Purpose of the Study:

• To investigate the in vitro heparin effect of PCCs at clinically relevant concentrations in whole blood.
• To compare a high-heparin PCC preparation with a new heparin-free PCC preparation.

Main Methods:

• Whole blood from ten healthy volunteers was tested using the NATEM assay on a ROTEM® thromboelastometer.
• Heparin-containing (Prothromplex®) and heparin-free (Cofact®) PCCs were tested at 0.31, 0.63, and 1.25 IU/ml.
• Protamine was added to assess reversibility of the heparin effect.

Main Results:

• The heparin PCC preparation showed a significant, concentration-dependent prolongation of clotting time (CT) and clot formation time (CFT), with reduced maximum clot firmness (MCF).
• The observed heparin effect was reversible with protamine.
• The heparin-free PCC did not impact coagulation onset or thrombus formation, as indicated by the alpha-angle.

Conclusions:

• The heparin content in PCCs exerts a significant heparin effect in thromboelastometry at clinically relevant concentrations.
• These findings support previous reports and emphasize the importance of considering the heparin component of PCCs in clinical settings.
• The heparin-free PCC demonstrated no procoagulant or anticoagulant effects in this study.