Lipoprotein(a), PCSK9 Inhibition, and Cardiovascular Risk

Background: Lipoprotein(a) [Lp(a)] may play a causal role in atherosclerosis. PCSK9 (proprotein convertase subtilisin/kexin 9) inhibitors have been shown to significantly reduce plasma Lp(a) concentration. However, the relationship between Lp(a) levels, PCSK9 inhibition, and cardiovascular risk reduction remains undefined. Methods: Lp(a) was measured in 25 096 patients in the FOURIER trial (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk), a randomized trial of evolocumab versus placebo in patients with established atherosclerotic cardiovascular disease (median follow-up, 2.2 years). Cox models were used to assess the independent prognostic value of Lp(a) and the efficacy of evolocumab for coronary risk reduction by baseline Lp(a) concentration. Results: The median (interquartile range) baseline Lp(a) concentration was 37 (13–165) nmol/L. In the placebo arm, patients with baseline Lp(a) in the highest quartile had a higher risk of coronary heart disease death,...