Prognostic value of the Aggregate Index of Systemic Inflammation for 12-month major adverse cardiovascular events in patients with STEMI undergoing primary PCI
Aims: ST-segment elevation myocardial infarction (STEMI) remains a major cause of morbidity and mortality despite advances in reperfusion strategies. Systemic inflammation plays a key role in the pathophysiology of acute myocardial infarction and may influence long-term outcomes. The Aggregate Index of Systemic Inflammation (AISI) is a novel composite biomarker reflecting overall inflammatory burden. However, its prognostic value in STEMI patients undergoing primary percutaneous coronary intervention (PCI) remains insufficiently explored.Methods: In this retrospective, single-center cohort study, a total of 1.224 patients with STEMI who underwent primary PCI between November 2022 and April 2025 were included. AISI was calculated using admission hematological parameters, and patients were stratified into tertiles. The primary endpoint was major adverse cardiovascular events (MACE), defined as a composite of all-cause mortality, reinfarction, and repeat revascularization at 12 months. Cox proportional hazards models were used to identify independent predictors of MACE. Restricted cubic spline (RCS) analysis was performed to assess non-linear associations, and AISI was log-transformed for further modeling.Results: During a 12-month follow-up, the incidence of MACE increased significantly across AISI tertiles (14.2%, 16.7%, and 23.0%, respectively; p=0.003). In univariate analysis, higher AISI levels were associated with increased risk of MACE. In multivariable Cox regression analysis, AISI remained an independent predictor of MACE (HR: 1.001, 95% CI: 1.000-1.001, p=0.001). Restricted cubic spline (RCS) analysis demonstrated a non-linear association between AISI and MACE (p for non linearity