Evaluation of Haematological and Biochemical Markers as Simple Predictors of In-hospital Mortality in Infective Endocarditis

Abstract

Background: Infective endocarditis (IE) is a serious illness with high morbidity and mortality. There is a need for early recognition of patients at risk of adverse events to guide management decisions and improve outcomes. Recent studies have identified inflammatory biomarkers including C-reactive protein (CRP), neutrophil-to-lymphocyte-ratio (NLR), and platelet-to-lymphocyte ratio (PLR) as prognostic factors in IE. We sought to identify simple laboratory parameters in IE patients as predictors of in-hospital mortality in our centre. Method: This is a single centre retrospective review of all patients diagnosed with definite IE (using Modified Duke Criteria) at St Vincent's Hospital, Melbourne, between January 1999-December 2012. Results: 288 patients were identified, 68.06% males and 31.94% females (mean age, 53.58 years). In-hospital mortality was 20.14% (54/288) and surgical management was 30.9%(89/288). Predictors of in-hospital mortality were higher admission levels of white cell count (WCC), neutrophil count, NLR, CRP and bilirubin [p < 0.001, p = 0.004, p = 0.010, p = 0.017 and p = 0.001 respectively] and lower admission levels of serum albumin and platelet count [p = 0.003 and p = 0.001 respectively]. On stepwise multiple logistic regression analysis, higher white cell and lower platelet counts were identified as independent predictors of in-hospital mortality when adjusted for age, sex, length of stay, and other inflammatory indices [OR 1.1253, p = 0.002 and OR = 0.9944, p = 0.001 respectively]. Conclusion: Our findings suggest that higher white cell and lower platelet counts are independently associated with in-hospital mortality in IE patients. These simple and inexpensive inflammatory indices may be useful for early identification of high-risk IE patients.