Increased lipoprotein(a) levels as an independent risk factor for idiopathic and recurrent venous thrombosis

Abstract number: P1432

Marcucci R., Alessandrello Liotta A., Rogolino A., Lari B., Mannini L., Gori A.M., Lenti M., Abbate R., Gensini G.F., Prisco D.

University of Florence, Italy

Elevated lipoprotein (a) [Lp(a)] plasma levels are an established risk factor for arterial thrombotic disease. At variance, contrasting and scarce data are available on the role of increased Lp(a) plasma levels in venous thromboembolism (VTE). We studied 603 (209 M/394 F) consecutive unselected patients, with a history of VTE referred to our Thrombosis Center from January 2000 to January 2001, six months to one year after the acute event. Exclusion criteria were a history of arterial thromboembolism and the presence of a cancer. The control population was of 300 healthy subjects (100 M/200 F) recruited from partners or friends of the patients. We determined on patients and controls: plasma levels of Lp(a); antithrombin, protein C and protein S; activated protein C resistance; FV Leiden; polymorphism G20210A of the prothrombin; fasting Hcy levels; antiphospholipid antibodies (Lupus Anticoagulant and anticardiolipin antibodies). Lp(a) levels were significantly higher in patients than in controls (124 (1–1497) mg L^-1 vs. 102 (9–695) mg L^-1; P < 0.05). Lp(a) levels above 300 mg L^-1 were detected in 146/603 (24.2%) patients and in 41/300 (31.6%) controls (P < 0.005).At the multivariate analysis (adjusted for all acquired and hemostasis-related risk factors) the role of elevated Lp(a) levels as an independent risk factor for VTE was demonstrated (OR = 2.1 (1.3–3.4); P < 0.001). In 368/603 (61%) patients no circumstantial risk factor was present: among these patients the role of elevated Lp(a) levels as independent risk factor was confirmed (OR = 3.1 (1.3–3.4); P < 0.001) whereas in 235/603 (39%) patients with a secondary episode of VTE we were not able to document a role of elevated Lp(a) levels. 136/603 (22.5%) patients had a recurrent VTE. independent risk factors for recurrent VTE were: Lp(a) levels >300 mg L^-1 (OR = 5.1 (3.1–8.4); P < 0.001), hyperhomocysteinemia (OR = 5.0 (3.0–8.4); P < 0.001) and the presence of both FV Leiden and FII polymorphisms (OR = 3.7 (1.6–8.4); P < 0.001). These results suggest the possible utility of including Lp(a) determination in the evaluation of patients with a history of venous thrombosis and in particular in patients with idiopathic and recurrent VTE.