Systematic Immune-Inflammation Index Predicts Embolic Events in Infective Endocarditis

Infective endocarditis (IE) is a life-threatening disease with embolisms occurring in 20%-50% of cases. We aimed to evaluate the value of the systemic immune-inflammation index (SII) in predicting embolic events (EEs) in patients with infective endocarditis.A total of 186 patients diagnosed with definite IE, who admitted to the Union Hospital affiliated to Tongji Medical College, Huazhong University of Science and Technology, were retrospectively identified from November 2011 to March 2019.The median (interquartile) age of the patients was 46 (32-57) years. Viridans group streptococci were the most common microorganism identified from blood culture (24.7%). The most frequent complication was heart failure (64.2%), followed by EEs (30.2%). Patients complicated with EEs presented a significantly higher SII than those without EEs (1605.38 versus 1039.61, P = 0.001). SII had an area under the curve (AUC) value for EEs of 0.661 (95% CI: 0.575-0.747, P = 0.001), which predicted the presence of EEs with a sensitivity of 42.6% and specificity of 86.3%. Multivariate logistic regression analysis revealed that SII (OR = 6.925; 95% CI: 1.035-46.318, P = 0.046) was an independent predictor of EEs in IE patients.We demonstrated that a high level of SII is associated with a higher likelihood of EEs. The SII may be a promising predictor for EEs in patients with IE.