Prevalence of infective endocarditis in patients with bloodstream infections and deployment of echocardiographic resources in a single-center registry
Authors: De Oliveira E K , Van Vaerenbergh K , Shumkova M , Beles M , Boel A , Cattoir L , Iturriagagoitia A , Moya A , Schelfaut D , Castelein T , Wouters S , Spapen J , Brouwers S , Penicka M , Van Camp G 
Published: January 2025

Abstract

Background
Improving early screening for Infective Endocarditis (IE) in bloodstream infections (BSIs) is crucial due to the high morbidity and mortality rates. Additionally, it is imperative to ensure the cost-effectiveness of imaging tests. Despite the potential of epidemiology to identify high-risk IE patients, there remains a significant lack of data on the prevalence of IE according to microbiological etiology in BSIs.

Purpose
To investigate the risk according to microbiological etiology and echocardiographic screening of IE cases among BSIs.

Methods
A single-center observational registry between January 2015 and December 2021. All consecutive hospitalized adults with BSIs were included. The echocardiographic screening for IE and the prevalence of definitive IE diagnosis was assessed. All clinically significant hemoculture with the same microorganism during the same hospitalization was considered as one BSI.

Results
Among 4939 BSIs related to 4242 admissions in 3708 patients analyzed [74 (64-83) years; 2882 (58.7%) male],133 (2.7%) BSIs were identified as definite IE. The most prevalent pathogens in BSIs (Figure 1) were Enterobacterales (48.3%), Staphylococcus aureus (11.5%), and Anaerobic species (7.6%). Patients with Streptococcus bovis complex BSI had the highest risk of IE (19.2%), followed by Listeria monocytogenes BSI (16.7%) and Enterococcus faecalis BSI (15.5%). Following the selection of only IE typical species according to the main IE diagnostics criteria (Figure 1), the high IE risks are underestimated in some aggregation groups (Streptococci) or no considering some as non-typical (Listeria monocytogenes), or more clear risks in more detailed microorganisms (Streptococcus gallolyticus) or in specific species in the presence of intracardiac material. The highest rate of echocardiography screening for IE (Figure 2) occurred in the BSIs caused by Staphylococcus aureus with 75%, followed by Other Streptococci (72.7%), Staphylococcus lugdunensis (72.2%), and Streptococcus bovis complex (66.9%). Although the IE prevalence was high in the Listeria monocytogenes, Enterococcus faecalis, and HACEK BSIs, echocardiographic screening was performed from 41.7% to 66.3%. The echocardiography screening was higher in the presence of intracardiac prosthesis material, ranging from 40 to 100% of BSI with this condition. Among BSIs groups without IE cases, echocardiography screening was performed in 27.3% to 59.4%.

Conclusions
Our data illustrates a discrepancy between the prevalence of BSI species and their risk of IE. We also demonstrated how a narrow focus on typical species in the main IE diagnostic criteria can lead to a misleading risk analysis. Our analysis of echocardiographic screening in patients with BSIs for detecting IE demonstrated that it could be optimized considering these disparities.