Increased Serum Systemic Immune-Inflammation Index is Independently Associated With Severity of Carotid Artery Stenosis

Stroke is a significant contributor to morbidity and mortality. The present study investigated how the systemic immune inflammation index (SII) could be used to predict the likelihood of developing carotid artery stenosis (CAS), which can be seen using carotid artery angiography (CAAG). This study comprised 418 individuals who underwent CAAG for CAS. SII was calculated by multiplying the platelet count by the neutrophil/lymphocyte ratio (NLR). The patients were divided into two groups: non-critical and critical CAS (stenosis below %70 and above ≥70%, respectively). Compared with the non-critical CAS, the critical CAS group had greater high sensitivity C-reactive protein levels (4.5 [3.1-5.7] vs 3.9 [2-5] [mg/L], P < .001), NLR (4.1 [2.9-7.5] vs 2.9 [1.8-3.7], P < .001), platelet/lymphocyte ratio (233 [110-297] vs 119 [96-197], P < .001), and SII (860 [608-2455] vs 604 [458-740], P < .001). Receiver Operating Characteristic Curve analysis demonstrated the best cutoff value of 672.3 for SII to predict the critical CAS with 71.2% sensitivity and 60.1% specificity. According to our study, an increase in SII is an independent predictor of the severity of CAS in patients undergoing CAAG.