Systemic Immune-Inflammation Index Predicted Presence and Severity of Coronary Artery Disease

Objective: We aimed to investigate whether systemic immune-inflammation index, an easily available inflammatory and immune response marker, is associated with SYNTAX score (SS) in patients admitted with suspected CAD who underwent coronary angiography (CAG). Materials and Methods: Evaluated retrospectively were 456 patients who CAG from the cardiology outpatient clinic between January 2020 and January 2022. The SII was calculated by the formula neutrophil × platelet / lymphocyte. SS scores were divided into 3 groups as <22 (lowest), 22-32 (intermediate), and ≥32 (highest). Those with an SS of 0 were taken as the control group. Results: Median were higher in CAD group compared to control group SII (631.0 vs 381.5, p< 0.001), and a positive correlation was found between SS and SII (r= 0.578, p<0.001) levels. Median SII levels were found to be higher as SS severity increased (p< 0.05 for each SS group). The cut-off value of SII in predicting the presence of CAD was >594.2, with 56.7% sensitivity and 91.1% specificity (AUC ± SE = 0.807 ± 0.020, p < 0.001). In addition, it was found that SII predicted lowest SS group compared to the control group (OR = 1.06; p < 0.001), intermediate SS compared to lowest SS (OR = 1.03; p < 0.001), and highest SS compared to intermediate SS (OR = 1.04; p < 0.001). Conclusion: SII has the potential to be a screening marker for presence and severity of CAD before CAG. This study demonstrates that SII is independently associated with coronary atherosclerosis burden.