Abstract
Lipoprotein(a) (Lp(a)) is a genetically determined lipoprotein with proatherogenic and prothrombotic properties. Its prognostic role in patients undergoing percutaneous coronary intervention (PCI) remains incompletely defined. This systematic review evaluates the association between elevated Lp(a) and cardiovascular outcomes after PCI. A comprehensive search of PubMed, Embase, Scopus, IEEE Xplore, and Web of Science was conducted for studies published between 2021 and 2025. Observational studies evaluating elevated Lp(a) and cardiovascular outcomes in PCI patients were included. Methodological quality was assessed using the Newcastle-Ottawa Scale (NOS). Eight studies comprising 23,421 patients were included. Elevated Lp(a) thresholds ranged from ≥30 mg/dL to ≥50 mg/dL. Seven studies demonstrated a significant positive association between elevated Lp(a) and adverse outcomes, with hazard ratios for major adverse cardiovascular events (MACEs) ranging from 1.14 to 4.29. Elevated Lp(a) was consistently associated with increased risks of myocardial infarction (HR 1.79), stent thrombosis (HR 1.83), and repeat revascularisation. One study in patients with well-controlled low-density lipoprotein cholesterol (LDL-C; <70 mg/dL) found no significant association. Subgroup analyses revealed that the prognostic value of Lp(a) was most pronounced in high-risk patients and those with diabetes. One study demonstrated that a greater decrease in Lp(a) over 12 months was associated with lower MACE risk. NOS assessment rated seven studies as high quality and one as moderate quality. Elevated Lp(a) is independently associated with increased risk of adverse cardiovascular outcomes after PCI, although this risk may be attenuated by aggressive LDL-C lowering. These findings may support the consideration of routine Lp(a) measurement in PCI patients for risk stratification and to help inform secondary prevention strategies, although confirmation from prospective and interventional studies is warranted.