Abstract
Early and accurate risk prediction is an important clinical demand in patients with infective endocarditis (IE). The platelet-to-lymphocyte ratio (PLR) is an independent predictor of worse prognosis in various cardiovascular diseases. The aim of this study was to determine the value of PLR in the prediction of in-hospital mortality among IE patients. We retrospectively analyzed the clinical, laboratory, and echocardiographic data of 59 adult patients with definite IE and in 40 adult controls. In-hospital mortality occurred in 16 (27%) patients. Vegetation size, levels of high-sensitive C-reactive protein and procalcitonin, neutrophil-to-lymphocyte ratio, and PLR were significantly higher in the in-hospital-mortality-positive group than in the in-hospital-mortality-negative group (p = 0.004, p = 0.009, p = 0.030, p = 0.001, and p = 0.008, respectively). Lymphocyte count was, however, significantly lower in the in-hospital-mortality-positive group (p = 0.004). In the receiver-operating characteristic analysis, PLRs over 191.01 predicted in-hospital mortality with 56.3% sensitivity and 81.4% specificity [area under the curve 0.725, 95% confidence interval (CI) 0.594-0.833; p = 0.0027]. In the multivariate analysis, PLR was found to be an independent predictor of in-hospital mortality in patients with IE (odds ratio 1.022, 95% CI 1.003-1.042; p = 0.021). In conclusion, higher PLR may predict in-hospital mortality in patients with IE.