Assessment of Lipoprotein(a) and Endogenous Fibrinolysis in Atherosclerotic Cardiovascular Disease/Aortic Valve Disease

The Global Thrombosis Test (Thromboquest Limited, UK) is an in vitro method imitating high shear stress conditions akin to that which exist in a severely stenosed artery. The test measures platelet reactivity (occlusion time) and endogenous fibrinolysis time (lysis time). Thromboelastography is a technique that assesses the whole process of clotting and its viscoelastic properties, from the initial activation and aggregation of platelets, to the role of thrombin and finally the stability of the formed clot, as a measure of fibrinolytic resistance. Plasma will be stored for subsequent analysis of other thrombotic, fibrinolytic, inflammatory and coagulation markers as deemed appropriate. For patients deemed eligible for treatment with either a PCSK9i or inclisiran, this will be assessed prior to commencing treatment and also 3-6 months after starting treatment. This will only be assessed once for patients with moderate or severe aortic valve calcification.

Lp(a) will be measured by particle enhanced immunotubidimetricassay. Human lipoprotein (a) agglutinates with latex particles coated with anti-Lp(a) antibodies. The precipitate is determined turbidimetrically at 800 / 660 nm. The platform employed will be the Roche® Immunoassay Analyser (Roche Diagnostics GmbH, Sandhofer Strasse 116, D-68305 Mannheim). Traceability: This method has been standardized against the IFCC (International Federation of Clinical Chemistry) reference material SRM2B for nmol/L. For patients deemed eligible for treatment with either a PCSK9i or inclisiran, this will be assessed prior to commencing treatment and also 3-6 months after starting treatment. This will only be assessed once for patients with moderate or severe aortic valve calcification.