Systemic immune-inflammation index predicts no-reflow phenomenon after primary percutaneous coronary intervention

Systemic immune-inflammation index (SII), on the basis of lymphocyte, neutrophil and platelet counts had been published to be a good prognostic factor in coronary artery disease. Nevertheless, the prognostic value of Systemic immune-inflammation index (SII) in a condition of no-reflow phenomenon (NRP) remains inconsistent, we evaluated the SII as a simple calculated tool for predicting the NRP among patients with STEMI who underwent primary percutaneus coronary intervention (PCI).

510 consecutive acute STEMI patients who underwent primary PCI within 12 h from symptom onset from October 2015 to January 2020 were enrolled in our study. The receiver-operating characteristic (ROC) curve was used to determine the cut-off value of SII to predict the no-reflow. Multivariate stepwise logistic regression, including covariates found to have a significant association with NRP in univariate analysis, was used to identify independent predictors of no-reflow.

A ROC curve analysis showed that the best cut-off value of SII for predicting no-reflow was 1028, with sensitivity and specificity of 79% and 70, respectively (AUC, 0.839; 95% CI 0.797-0.881). An ROC curve comparison analysis was performed to compare the SII with NLR and PLR. Multivariate analysis revealed that SII ≥1028 value (OR = 6.622, 95% confidence interval (CI): 3.802-11.627, p < .001), not using aspirin prior to admission (OR = 0.431, 95%CI: 0.236-0.786, p = .006), and CRP (OR = 1.004, 95%CI: 1.001-1.008, p = .041) were independent predictors related to occurrence of NRP after primary PCI in patients with acute STEMI.

SII levels are independently associated with the NRP in patients undergoing primary PCI for acute STEMI. High SII may be a promising indicator for the prediction of NRP in these patients.