Predictive Value of Systemic Inflammation Score for Contrast-Associated Acute Kidney Injury and Adverse Outcomes Among Patients Undergoing Elective Percutaneous Coronary Intervention

Purpose: Prior research has demonstrated a key role of systemic inflammatory state in the pathogenesis and progression of contrastassociated acute kidney injury (CA-AKI). Recently, the systemic inflammation score (SIS) has been introduced to evaluate the inflammatory status, utilizing the lymphocyte-to-monocyte ratio (LMR) and albumin. The primary objective of this study was to determine whether the SIS can predict CA-AKI and long-term prognosis in patients undergoing elective percutaneous coronary Patients and Methods: A total of 5726 patients who underwent elective PCI were included from January 2012 to December 2018. The primary outcome was CA-AKI, defined as an increase in serum creatinine (SCr) >0.3 mg/dl or >50% than baseline SCr within 48 h after the PCI procedure. The secondary outcome was long-term mortality. All patients were classified into low- and high-SIS groups. Results: During hospitalization, 349 (6.1%) patients developed CA-AKI. Multivariate logistic regression analysis showed that patients in the high SIS group had a 1.47-fold higher risk of developing CA-AKI than those in the low SIS group [odds ratio (OR): 1.50, 95% confidence interval (CI): 1.12-2.01, P =0.006]. Furthermore, the SIS showed the greatest prediction performance for CA-AKI compared with other inflammatory hematological ratios. In the multivariate Cox regression analysis, the high SIS group was found to be closely associated with long-term mortality [hazard ratio (HR): 1.58, 95% CI: 1.26-1.97, P <0.001, vs low SIS group]. The Kaplan-Meier curve analysis also demonstrated a difference in long-term mortality between the two groups (Log rank test, P <0.001).Conclusion: The SIS was closely associated with CA-AKI and long-term mortality in patients after elective PCI. Thus, more attention should be paid to exploring the potential benefits of anti-inflammatory strategies in preventing CA-AKI and improving the prognosis of patients undergoing PCI.