Coagulation in familial hypercholesterolemic patients: effect of current hypolipidemic treatment and anticoagulants

Familial hypercholesterolemia (FH) is a relatively rare genetic disease associated with high serum cholesterol levels but also with abnormalities in blood coagulation. Novel pharmacotherapeutic approaches in FH including proprotein convertase subtilisin/kexin type 9 antibodies (PCSK9Ab) are very efficient in decreasing cholesterol levels but their impact on coagulation in FH is not yet established. Therefore, we hypothesized that these novel antidyslipidemic drugs can positively impact blood coagulation due to their more potent effect on cholesterol. A total of 15 healthy volunteers and all 15 available patients with severe FH treated at the University Hospital Hradec Králové were enrolled, coagulation was assessed by mechanic coagulometer, and the impact of four clinically used direct anticoagulants was analyzed ex vivo. FH patients were treated effectively as their total cholesterol was 4.11 ± 1.57 mM and LDL cholesterol was 2.44 ± 1.46 mM, which were even lower values than detected in our generally healthy controls. Twelve from the 15 FH patients were finally analyzed as 3 were treated with anticoagulants. Coagulation in FH patients was prolonged more extensively by dabigatran and rivaroxaban, when compared to healthy controls. Treatment with PCSK9Ab or lipid apheresis did not seem to have a significant effect on coagulation. The latter procedure however significantly decreased serum levels of one vitamin K form, MK4. Shorter coagulation time was associated with higher levels of LDL, non-HDL, and total cholesterol. Current treatment of FH seems to improve the effects of direct anticoagulants beyond known effects on LDL cholesterol levels.