Systemic Immune-Inflammation Index Predicts Contrast-Induced Acute Kidney Injury in Patients Undergoing Coronary Angiography: A Cross-Sectional Study

Background and AimsSystemic immune-inflammation index (SII) is an emerging indicator and correlated to the incidence of cardiovascular diseases. This study aimed to explore the association between SII and contrast-induced acute kidney injury (CI-AKI). MethodsIn this retrospective cross-sectional study, 4,381 subjects undergoing coronary angiography (CAG) were included. SII is defined as neutrophil count x platelet count/lymphocyte count. CI-AKI was determined by the elevation of serum creatinine (Scr). Multivariable linear and logistic regression analysis were used to determine the relationship of SII with Scr and CI-AKI, respectively. Receiver operator characteristic (ROC) analysis, structural equation model analysis, and subgroup analysis were also performed. ResultsOverall, 786 (17.9%) patients suffered CI-AKI after the intravascular contrast administration. The subjects were 67.1 +/- 10.8 years wold, with a mean SII of 5.72 x 10(11)/L. Multivariable linear regression analysis showed that SII linearly increased with the proportion of Scr elevation (beta [95% confidence interval, CI] = 0.315 [0.206 to 0.424], P < 0.001). Multivariable logistic regression analysis demonstrated that higher SII was associated with an increased incidence of CI-AKI ([>= 12 vs. <3 x 10(11)/L]: odds ratio, OR [95% CI] = 2.914 [2.121 to 4.003], P < 0.001). Subgroup analysis showed consistent results. ROC analysis identified a good predictive value of SII on CI-AKI (area under the ROC curve [95% CI]: 0.625 [0.602 to 0.647]). The structural equation model verified a more remarkable direct effect of SII (beta = 0.102, P < 0.001) on CI-AKI compared to C-reactive protein (beta = 0.070, P < 0.001). ConclusionsSII is an independent predictor for CI-AKI in patients undergoing CAG procedures.

Automated summary

SII is an independent predictor for CI-AKI in patients undergoing CAG procedures. SII is linearly associated with the proportion of Scr elevation and higher SII is associated with an increased incidence of CI-AKI. SII has good predictive value and a more remarkable direct effect on CI-AKI compared to C-reactive protein.