Effect of heparins on thrombin generation in hemophilic plasma supplemented with FVIII, FVIIa, or FEIBA.

Central venous catheters assist infusion of coagulation factors in hemophiliacs but can be problematic due to mechanical dysfunction, infection, and thrombosis. The effect of low molecular weight heparin, unfractionated heparin, or covalent antithrombin-heparin complex on thrombin generation in factor concentrate-supplemented hemophilic plasma were studied. Thrombin levels were similar to normal plasma after the addition of factor eight inhibitor bypassing agent to hemophilic plasma. At 0.2 U/ml of heparin, covalent antithrombin-heparin inhibited free thrombin generation to a greater degree than heparin and low molecular weight heparin. Covalent anti-thrombin-heparin may give a greater anticoagulant response in hemophilic plasma supplemented with factor VIII or factor VIIa than with factor eight inhibitor bypassing agent. Requirements for heparin in hemophilic patients with thrombosis may depend on the procoagulant treatment used.