Systemic Immune-Inflammatory Index as a Determinant of Atherosclerotic Burden and High-Risk Patients with Acute Coronary Syndromes

Abstract

Background: Systemic immune-inflammatory index (SII), which is derived from neutrophil, platelet and lymphocyte counts, represents the homeostatic balance among inflammatory, immune and thrombotic status. The systemic immune-inflammatory index is superior to indices such as neutrophil-lymphocyte ratio in predicting prognosis in various malignancies, while it is shown to predict future cardiac events better than traditional risk factors after coronary intervention. Objectives: Herein, we aimed to evaluate the relationship of the systemic immune-inflammatory index with atherosclerotic burden and in-hospital complications in acute coronary syndrome patients. Methods: The clinical outcomes, such as extent of myocardial damage, atherosclerotic burden, bleeding, acute kidney injury, duration of hospital stay and in-hospital mortality, were evaluated in a retrospective cohort of 309 consecutive acute coronary syndrome patients. The systemic immune-inflammatory index was calculated as (Platelet X Neutrophil)/Lymphocyte count on admission. Study population was categorized into tertiles with regard to systemic immune-inflammatory index. A p value of <0.05 was considered statistically significant. Results: The highest systemic immune-inflammatory index values were within ST elevation myocardial infarction patients (641.4 in unstable angina pectoris, 843.0 in non-ST elevation myocardial infarction patients and 996.0 in ST elevation myocardial infarction patients; p=0.004). Maximal troponin concentration (0.94 vs. 1.26 vs. 3; p<0.001), number of diseased vessels (1 vs. 2 vs. 2; p<0.001), the SYNTAX (synergy between percutaneous coronary intervention with taxus and coronary artery bypass grafting) score (9 vs. 14 vs. 17.5; p<0.001) and duration of hospital stay (2 vs. 2 vs. 3; p<0.001) also increased with increasing SIItertile (tertile1 vs. tertile 2 vs. tertile 3). Systemic immune-inflammatory index was an independent predictor of SYNTAX score (ß: 0.232 [0.001 to 0.003]; p<0.001), extent of myocardial damage (ß: 0.152 [0 to 0.001]; p=0.005) and duration of hospital stay (ß: 0.168 [0.0 to 0.001]; p=0.003). Conclusions: This study has demonstrated that the systemic immune-inflammatory index, a simple hematological index, is a marker of atherosclerotic burden and longer hospital stay on well-known risk factors in high risk acute coronary syndrome patients.