The association between systemic inflammatory response index and in-hospital mortality in patients with infective endocarditis

Background Infective endocarditis (IE) has a significant mortality, and early identification of high-risk patients and prediction of poor outcomes is of great significance. In recent years, increasing research has revealed the predictors associated with infective endocarditis prognosis. Systemic inflammatory response index (SIRI) is an important new indicator of inflammation. So far, there have been no reports on the relationship between SIRI and the prognosis of IE patients. Hypothesis The purpose of this study was to explore the value of SIRI in predicting in-hospital death for patients with infective endocarditis (IE), so as to provide reference for improving the prognosis of patients with IE. Method A retrospective analysis was performed on the clinical data of patients with IE admitted to the First Affiliated Hospital of Nanjing Medical University from January 2017 to December 2019. SIRI was calculated according to the blood routine results of patients at admission; receiver operating characteristic curve was employed to determined the optimal cutoff value of SIRI. Patients were divided into groups (low SIRI group and high SIRI group; nonsurvivor group and survivor group) according to the levels of SIRI or their prognosis, and the general clinical features of the two groups were compared. Univariate and multivariate logistic regression analysis were performed to analyze the independent prognostic factors of in-hospital death in IE patients. Results A total of 147 IE patients meeting the diagnostic criteria were included, including 102 males (69.4%) and 45 females (30.6%). There was statistically significant difference in SIRI level between nonsurvivor group and survivor group (p < .05). After adjusting for the related factors, the risk of in-hospital death in the high SIRI was still a risk of in-hospital death with statistical significance (hazard ratio = 5.053, 95% confidence interval: 1.426-17.905, p = .012). Conclusions Higher SIRI level is independently associated with the risk of in-hospital death in IE patients, and can be an independent predictor of poor outcome in IE patients.