Increased plasma levels of lipoprotein(a) and the risk of idiopathic and recurrent venous thromboembolism

Elevated lipoprotein(a) [Lp(a)] levels are a recognized risk factor for cardiovascular disease; however, little is known about their effects on venous thromboembolism. We conducted a case-control study of 603 adult patients with a history of venous thromboembolism (at least 6 months after the acute event) and 430 healthy subjects. We measured Lp(a), homocysteine, and antithrombin levels, factor V Leiden and factor II (prothrombin) polymorphisms, and anticardiolipin antibodies. Lp(a) levels >300 mg/L were found in 24% (n = 146) of the patients and in 13% (n = 58) of the controls ( P = 0.005). In a multivariate analysis adjusted for acquired and hemostasis-related risk factors, there was an independent association between elevated (>300 mg/L) Lp(a) levels and venous thromboembolism (odds ratio = 2.1; 95% confidence interval: 1.4 to 3.2; P = 0.002). These results were confirmed in the 341 patients with idiopathic venous thromboembolism, as well as in those with recurrent thromboembolism. These results show that Lp(a) is an independent risk factor for venous thromboembolism in adults, suggesting that it may be involved in the pathogenesis of idiopathic and recurrent disease.