Impact of lipoprotein apheresis on thrombotic parameters in patients with refractory angina and raised lipoprotein(a): Findings from a randomized controlled cross-over trial

BACKGROUND: Raised lipoprotein(a) [Lp(a)] is a cardiovascular risk factor common in patients with refractory angina. The apolipoprotein(a) component of Lp(a) exhibits structural homology with plasminogen and can enhance thrombosis and impair fibrinolysis. OBJECTIVES: The objective of the study was to assess the effect of lipoprotein apheresis on markers of thrombosis and fibrinolysis in patients with high Lp(a). METHODS: In a prospective, single-blind, crossover trial, 20 patients with refractory angina and raised Lp(a) > 50 mg/dL were randomized to three months of weekly lipoprotein apheresis or sham. Blood taken before and after apheresis/sham was assessed using the Global Thrombosis Test, to assess time taken for in vitro thrombus formation (occlusion time) and endogenous fibrinolysis (lysis time), as well as von Willebrand Factor, fibrinogen, D-dimer, thrombin/anti-thrombin III complex, prothrombin fragments 1 + 2, and thrombin generation assays. RESULTS: Lp(a) was significantly reduced by apheresis (100.2 [interquartile range {IQR}, 69.6143.0] vs 24.8 [17.2,34.0] mg/dL, P = .0001) but not by sham (P = .0001 between treatment arms). Apheresis prolonged occlusion time (576 ± 116 s vs 723 ± 142 s, P