Therapeutic Effects of PCSK9 Inhibitors on Lp(a)-Associated Atherosclerosis: Evidence and Perspectives

ABSTRACT: Lipoprotein(a) [Lp(a)] is a genetically determined independent risk factor for atherosclerotic cardiovascular disease (ASCVD) that drives a significant residual risk through proatherogenic, proinflammatory, and prothrombotic pathways. However, current mainstay lipid-lowering therapies such as statins have limited efficacy in reducing Lp(a) levels, highlighting a critical therapeutic gap. This review aims to synthesize evidence on the role of Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) inhibitors in targeting Lp(a). We systematically searched PubMed and Embase for clinical trials and mechanistic studies (2010-2025), using the PRISMA and AMSTAR-2 frameworks to ensure methodological rigor and demonstrated that PCSK9 inhibitors (eg, alirocumab, evolocumab, and tafolecimab) not only reduced low-density lipoprotein (LDL-C) by 55%-60% but also lowered Lp(a) by 20%-30%. The efficacy of these agents varies ethnically, with tafolecimab showing superior performance in East Asian populations, which is partly attributable to the higher prevalence of the PCSK9 R46L loss-of-function allele. Mechanistically, PCSK9 inhibitors lowered Lp(a) levels through 2 pathways: suppression of hepatic synthesis and enhanced plasma clearance. This evidence supports the 2023 ESC guidelines, which issued a Class IIa recommendation for PCSK9 inhibitor use in patients with ASCVD and elevated Lp(a) levels. Given the evolving landscape, further research is warranted to confirm the role of these therapies in precision medicine paradigms for managing Lp(a)-associated risks.