Relationship between systemic immune-inflammation Index and contrast-induced acute kidney injury in cardiovascular patients: systematic review and meta-analysis

Introduction: Contrast-induced acute kidney injury (CI-AKI) imposes high costs and various complications on individuals and society. Considering that inflammation is a significant risk factor for CI-AKI incidence, the present research aimed to investigate the relationship between the systematic immune-inflammation (SII) index and the CI-AKI risk in cardiovascular patients using the systematic review and meta-analysis method. Materials and Methods: In the present study, ProQuest, PubMed, Embase, Web of Science, Cochrane, Scopus, and Google Scholar databases were used to search for articles published until October 16, 2024. Data analysis was conducted using the STATA 14 software, and tests with P values < 0.05 were considered statistically significant. Results: There was no significant association between the SII index and risk of CI-AKI in patients who underwent carotid artery angiography (OR: 1; 95% CI: 1, 1.01) or coronary angiography (OR: 1.96; 95% CI: 0.94, 4.11). However, in patients undergoing percutaneous coronary intervention (PCI) (OR: 1.01; 95% CI: 1, 1.02), high SII index levels increased the risk of CI-AKI. High SII index levels (OR: 1.01; 95% CI: 1.01, 1.02), higher ages (OR: 1.04; 95% CI: 1.02, 1.06), high-sensitivity C-reactive protein (hs-CRP) (OR: 1.01; 95% CI: 1, 1.02), hypertension (OR: 1.63; 95% CI: 1.31, 2.03), diabetes mellitus (OR: 1.73; 95% CI: 1.12, 2.68), neutrophil to lymphocyte ratio (NLR) (OR: 1.09; 95% CI: 1.01, 1.17), and neutrophil count (OR: 1.12; 95% CI: 1.08, 1.16) increased the risk of CI-AKI in cardiovascular patients. On the other hand, estimated glomerular filtration rate (eGFR) (OR: 0.98; 95% CI: 0.98, 0.99), lymphocyte count (OR: 0.47; 95% CI: 0.31, 0.71), and hemoglobin (OR: 0.97; 95% CI: 0.96, 0.98), albumin (OR: 0.96; 95% CI: 0.93, 0.99) in individuals with CIN were lower than those in the no-CIN group. Conclusion: High systemic immune-inflammation index levels, age, NLR, hs-CRP, hypertension, diabetes mellitus, and neutrophil count were among the risk factors of CI-AKI incidence in cardiovascular patients. Registration: This study has been compiled based on the PRISMA checklist, and its protocol was registered on the PROSPERO (ID: CRD42024604243) and Research Registry (UIN: reviewregistry1904) website.