Evaluation of Laboratory Predictors for In-Hospital Mortality in Infective Endocarditis and Negative Blood Culture Pattern Characteristics

Objective: This study aimed to identify possible differences between blood culture-negative and blood culture-positive groups of infective endocarditis (IE), and explore the associations between biological parameters and in-hospital mortality.

Methods: This was a retrospective study of patients hospitalized for IE between 2007 and 2017. Epidemiological, clinical and paraclinical characteristics, by blood culture-negative and positive groups, were collected. The best predictors of in-hospital mortality based on the receiver-operating characteristic (ROC) analysis and AUC (area under the curve) results were identified.

Results: A total of 126 IE patients were included, 54% with negative blood cultures at admission. Overall, the in-hospital mortality was 28.6%, higher in the blood culture-negative than positive group (17.5% vs. 11.1%, p = 0.207). A significant increase in the Model for End-Stage Liver Disease Excluding International Normalized Ratio (MELD-XI) score was observed in the blood culture-negative group (p = 0.004), but no baseline characteristics differed between the groups. The best laboratory predictors of in-hospital death in the total study group were the neutrophil count (AUC = 0.824), white blood cell count (AUC = 0.724) and MELD-XI score (AUC = 0.700).

Conclusion: Classic laboratory parameters, such as the white blood cell count and neutrophil count, were associated with in-hospital mortality in infective endocarditis. In addition, MELD-XI was a good predictor of in-hospital death.