Significance of Lipoprotein(a) in Coronary Artery Disease　― A Comparative Study of Patients Undergoing Percutaneous Coronary Intervention and Healthy Individuals ―

Background: Lipoprotein(a) is a risk factor for atherosclerotic cardiovascular disease (ASCVD). However, its distribution based on coronary artery disease (CAD) in the Japanese population remains unclear. We compared lipoprotein(a) distributions among patients with acute coronary syndrome (ACS), patients with chronic coronary syndrome (CCS), and controls. Methods and Results: We analyzed 3,710 individuals who visited Kagawa Prefectural Central Hospital from April 2019 to March 2024. Patients who underwent percutaneous coronary intervention (PCI) were classified into ACS (n=724) and CCS (n=579) groups. Another 2,407 individuals without ASCVD undergoing medical check-ups were the controls. Lipoprotein(a) levels were measured before PCI or during check-up. Distributions and associations with prevalent CAD were assessed using multivariable logistic regression. The mean ages were 70, 72, and 56 years in the ACS, CCS, and control groups, respectively (P<0.001). Median lipoprotein(a) levels were 13, 14, and 10 mg/dL in the ACS, CCS, and control groups, respectively (P<0.001). Proportions of patients with lipoprotein(a) >30 mg/dL were 19.1% and 26% (P<0.05), and proportions of patients with lipoprotein(a) >50 mg/dL were 7.8% and 11.5% in the ACS and CSS groups, respectively (P<0.05). Restricted cubic splines suggested continuous associations between lipoprotein(a) and prevalent ACS and CCS. Statin use did not affect intergroup differences. Conclusions: Lipoprotein(a) levels were higher in patients with CAD than in the controls, supporting its role as an independent risk marker.