Prognostic Value of Lipoprotein (a) in Japanese Patients with Acute Coronary Syndrome Surviving Primary Percutaneous Coronary Intervention to Discharge.

Previous studies investigating lipoprotein(a) [Lp(a)] as a prognostic factor in acute coronary syndrome (ACS) have yielded conflicting results, with limited data in Japanese populations. Inconsistent inclusion of early in-hospital deaths further limits clinical applicability for secondary prevention strategies.To evaluate the prognostic value of Lp(a) levels in ACS patients who underwent successful primary percutaneous coronary intervention (PCI) and survived to hospital discharge.This single-center retrospective study enrolled 347 consecutive Japanese ACS patients who underwent primary PCI between December 2016 and March 2021 and were discharged alive. Patients were stratified by Lp(a) levels: < 30 mg/dL (n = 275) and ≥ 30 mg/dL (n = 72). The primary endpoint was major adverse cardiac events (MACE), defined as all-cause death, nonfatal myocardial infarction, nonfatal stroke, and heart failure requiring hospitalization. Kaplan-Meier survival analysis and multivariable Cox regression models were performed.During a median follow-up of 37 months, 59 MACE events (17.0%) occurred. The median Lp(a) level was 14 mg/dL. Kaplan-Meier analysis showed no significant difference in MACE-free survival between groups (log-rank P = 0.46). In all multivariable analyses, Lp(a) ≥ 30 mg/dL was not associated with mid-term MACE. Significant predictors were age ≥ 70 years, male sex, and chronic kidney disease.Elevated Lp(a) levels did not significantly predict mid-term MACE in Japanese ACS patients surviving primary PCI. Traditional risk factors, including age, male sex, and chronic kidney disease, were the primary determinants of mid-term prognosis in this population.