Abstract:

Objective To evaluate the systemic immune inflammation index (SII) as a novel predictor of major adverse cardiovascular events (MACE) in patients with heart failure with reduced ejection fraction (HFrEF). Methods This retrospective cohort study enrolled 304 consecutive HFrEF patients admitted to the Department of Cardiology, Anshan Central Hospital between June 2022 and June 2024. Patients were followed until June 2025 and categorized according to MACE occurrence during followup into a MACE group (n=94) and a non-MACE group (n=210). Laboratory parameters and related indices were recorded. Univariate and multivariate binary logistic regression analyses were used to identify factors associated with MACE. The discriminative performance of SII for MACE was assessed by receiver operating characteristic (ROC) curve analysis and quantified by the area under the curve (AUC). Results Baseline characteristics, including sex, age, body mass index (BMI), hypertension, diabetes, prior percutaneous coronary intervention (PCI), white blood cell count, and liver and renal function tests, did not differ significantly between groups (P>0.05). Compared with the non-MACE group, the MACE group had higher smoking prevalence, higher neutrophil counts, platelet count, higher neutrophiltolymphocyte ratio (NLR), elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP), and higher SII (all P<0.05), while lymphocyte counts and serum albumin were significantly lower (P<0.05). In multivariate logistic regression, smoking history and SII remained independently associated with MACE risk in HFrEF patients (P<0.05). Conclusion SII is an independent predictor of MACE in patients with HFrEF. Measurement of SII may facilitate early identification of patients at high risk of adverse cardiovascular outcomes and inform targeted preventive strategies.

Key words: heart failure with reduced ejection fraction, major adverse cardiovascular events, systemic immune-inflammation index