Relationship between intracoronary thrombus burden and systemic immune-inflammation index in patients with ST-segment elevation myocardial infarction

This study aimed to evaluate the relationship between intracoronary thrombus burden and systemic immune-inflammation index (SII) and to compare the predictive capacity of SII together with the neutrophil-lymphocyte ratio (NLR), and the platelet-lymphocyte ratio (PLR) in patients with ST-elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PPCI).A total of 425 patients were included in the study. The clinical, laboratory, and demographic characteristics of the patients were recorded. The thrombus classification "Thrombolysis in myocardial infarction (TIMI)" was used to assess the intracoronary thrombus burden. According to the TIMI thrombus classification, 229 (54%) patients with low thrombus burden (grade 0-3) and 196 (46%) patients with high thrombus burden (grade 4 and 5) were compared. SII was calculated as platelet × neutrophil/lymphocyte counts.High NLR (OR: 1.068, 95% CI:1.023-1.404; p = 0.031), PLR(OR: 1.012, 95% CI:1.002-1.018; p = 0.043), SII(OR: 1.325, 95% CI: 1.156-1.879; p = 0.015) and low left ventricle ejection fraction (LVEF) (OR: 0.957, 95% CI:0.924-0.990; p = 0.012) were found to be independent predictors of high thrombus burden. SII values above 812 predicted a high thrombus burden with a sensitivity of 82% and specificity of 73% (AUC: 0.836; 95% CI:0.795-0.877; p < 0.001). This predictiveness of SII was stronger as compared to NLR (0.836 vs. 0.818, p = 0.043) and PLR (0.836 vs. 0.780, p < 0.001).SII is an independent predictor of high thrombus burden in patients with STEMI. In addition, SII is superior to NLR and PLR in this regard.