The Systemic Immune-Inflammation Index May Predict the Coronary Slow Flow Better Than High-Sensitivity C-Reactive Protein in Patients Undergoing Elective Coronary Angiography

METHODS: A total of 197 patients (102 patients with CSF; 95 patients with normal coronary flow) were included in this retrospective study. Clinical and angiographic characteristics of patients were obtained from hospital records. RESULTS: Patients with CSF had higher SII, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte (PLR), and high-sensitivity C-reactive protein (hsCRP) levels compared with the control group. Body mass index (p=0.022, OR 1.151, 95% CI 1.121–1.299), low-density lipoprotein (p=0.018, OR 1.028, 95% CI 1.005–1.052), hsCRP (p=0.044, OR 1.161, 95% CI 1.004–1.343), and SII (p < 0.001, OR 1.015, 95% CI 1.003–1.026) were independent predictors of CSF in the multivariable analysis. The optimal cutoff value of SII in predicting CSF was >877 in ROC curve analysis (p < 0.001, AUC = 0.892, 95% CI 0.848–0.936). This cutoff value of SII predicted the CSF with a sensitivity of 71.5% and specificity of 92.4%. Spearman correlation analysis showed a positive correlation between the mean TFC value and PLR, NLR, hsCRP, and SII. CONCLUSIONS: SII may be used as a better indicator for the prediction of CSF than hsCRP.