Abstract
OBJECTIVES: This research aimed to evaluate the influence of the systemic immunoinflammatory index (SII) on the development of major adverse cardiovascular events (MACE) in individuals with coronary heart disease (CHD) and heart failure (HF), as determined by propensity score matching (PSM). METHODS: The 218 patients with CHD and HF were divided into the MACE group and the non-MACE group. After balancing the baseline data of the two groups by PSM (76 cases in each group after matching, total sample 152 cases), the diagnostic value of SII for MACE was analyzed using the ROC curve to determine the optimal threshold value. The independent risk factors for MACE were analyzed using multifactorial Cox regression. Kaplan-Meier curves were employed to compare the MACE-free survival rates of patients with varying SII levels. RESULTS: PSM effectively balanced the baseline characteristics of the two groups, with absolute values of standardized mean difference for all variables < 0.1. Platelet counts, neutrophil counts, neutrophil-to-lymphocyte ratio, SII, C-reactive protein (CRP), and NT-proBNP levels were significantly higher in the MACE group than in the non-MACE group (P < 0.05). The ROC curve showed that the area under the curve (AUC) of SII after PSM was 0.788 (95% CI 0.714-0.860, P < 0.001), with an optimal threshold of 589.31 (sensitivity 81.58%, specificity 65.79%). Multifactorial Cox analysis showed that SII ≥ 589.31 (HR 1.92, 95% CI 1.18-3.14, P = 0.009), elevated CRP (HR 1.12, 95% CI 1.03-1.23, P = 0.010), and NT-proBNP (HR 1.01, 95% CI 1.01-1.01, P < 0.001) were independent risk factors for MACE. Kaplan-Meier analysis showed that the incidence of MACE was significantly higher in the high SII (≥ 589.31) group than in the low SII group (69.30% vs 23.40%, P < 0.05). CONCLUSIONS: Elevated SII increases the risk of MACE in patients with CHD with HF and is associated with poor survival.