Abstract
Since increased cholesterol levels are crucial in determining the development of atheroma,
their reduction represents a mainstay in primary and secondary cardiovascular prevention.
The most recent spectacular advancement in cholesterol-lowering therapy is represented
by proprotein convertase subtilisin/kexin type-9 (PCSK9) inhibitors. Although their
benefit over currently available treatments has been ascribed primarily to their strong
low-density lipoprotein (LDL)-cholesterol reducing action, several clues suggest that
PCSK9 inhibitors may also influence platelet function and blood coagulation. PCSK9
knockout mice develop less venous and arterial thrombosis and show reduced in vivo
platelet activation upon arterial injury. In patients with acute coronary syndromes
(ACSs) treated with P2Y12 inhibitors, a direct association between PCSK9 serum levels and residual platelet
reactivity was found. A direct correlation between urinary excretion of 11-dehydro-thromboxane-B2, a marker of in vivo platelet activation, and circulating PCSK9 levels was reported
in patients with atrial fibrillation. Moreover, recombinant human PCSK9 added in vitro
to human platelets potentiated activation induced by weak agonists. Finally, blood
clotting factor VIII (FVIII), which is associated with stroke and ACS risk, is cleared
from the circulation by members of the LDL receptor (LDLR) family. Given that PCSK9
degrades LDLR, it is conceivable that PCSK9 inhibitors by enhancing the expression
of LDLR may slightly decrease circulating FVIII, in this way contributing to the prevention
of cardiovascular events. This review aims to discuss the possible and hypothetical
interactions between PCSK9 and the haemostatic system and to examine the possible
pleiotropic effects of PCSK9 inhibitors in cardiovascular prevention.
Keywords
atherothrombosis - CD36 - dyslipidaemia - FVIII - LOX-1