Baddour, Larry M.

Abstract Background The incidence, epidemiology, and clinical characteristics of enterococcal bloodstream infection (BSI) have not previously been studied on a population-based level in the United States. Methods We utilized the Expanded Rochester Epidemiology Project medical records linkage system to conduct a contemporary 5-year, retrospective, population-based study of monomicrobial enterococcal (ME) BSI among adult residents of 8 counties in southeast Minnesota from January 1, 2018 to December 31, 2022. Results A total of 109 cases of ME-BSI were identified. The overall age- and sex-adjusted incidence rate was 6.7 per 100 000 person-years (95% confidence interval, 5.4–7.9). Multivariable analysis revealed that male sex (P < .001) and older age (P < .001) were each independently associated with increased incidence, whereas no temporal association was demonstrated (year effect, P = .475). The median age of incident cases was 76.8 years (interquartile range, 65.0–83.3). Urinary tract source was the most common presumed source (42.2%), and Enterococcus faecalis was the predominant (83.5%) pathogen. Overall, 14.4% of patients met modified Duke criteria for definite infective endocarditis. Cumulative mortality was 28.4% at 12 weeks and 43.1% at 1 year. Conclusions In this population-based study, ME-BSI was significantly associated with older age and male sex. There was a high rate of mortality at 12 weeks and 1 year, with ∼1 out of 7 cases complicated by definite infective endocarditis. These findings underscore the importance of ongoing investigation of this syndrome.

Background: The relationship between vegetation characteristics in Staphylococcus aureus infective endocarditis (IE) and blood culture time to positivity (TTP) has not been investigated. This study evaluates the correlation between vegetation length and TTP in patients with S. aureus IE. Methods: A retrospective cohort study was conducted that included 164 definite cases S. aureus IE. Vegetation length was determined by transesophageal echocardiography (TEE), and TTP was measured in hours from the initial time of blood culture incubation to positivity. Correlations between vegetation characteristics and TTP were analyzed using Spearman’s rank correlation coefficient. Results: A modest but statistically significant negative correlation was observed between vegetation length and TTP (Spearman ρ = −0.18, p = 0.020), suggesting that larger vegetations were associated with shorter TTP. No significant correlations were found for other vegetation characteristics (e.g., vegetation mobility, location, or number) and TTP. Conclusions: Larger vegetation size in S. aureus IE was associated with shorter TTP. These findings highlight the importance of vegetation size in the pathophysiology of S. aureus IE and its role in bacteremia dynamics.

Abstract Background There remains a lack of consensus regarding the postoperative treatment regimen in patients with native valve Staphylococcus aureus infective endocarditis who undergo surgical valve replacement or repair. Methods We conducted a multicenter retrospective review of patients with S aureus native valve endocarditis who underwent surgical valve replacement or repair at Mayo Clinic Enterprise (Minnesota, Florida, Arizona, and Mayo Clinic Health Systems) between 1 January 2012 and 31 December 2022. Postoperative treatment regimens were classified as either monotherapy with a methicillin-sensitive or methicillin-resistant S aureus active agent or combination therapy that included rifampin and/or gentamicin with either active agent. Results Of the 339 patients diagnosed with S aureus native valve endocarditis, 61 underwent surgical valve replacement or repair within the initial 6 weeks of antimicrobial therapy. A total of 12 (20.2%) patients died during the 1-year follow-up period. Between patients postoperatively treated with monotherapy (n = 33) and combination therapy (n = 28), a propensity score–weighted analysis revealed that combination therapy was associated with increased risk of 1-year mortality (P = .039), 6-month relapse (P = .016), and treatment-related adverse events (P < .001). Conclusions Among patients treated for native valve infective endocarditis caused by S aureus after valvular surgical intervention, all study outcomes—adverse events and drug-drug interactions, 6-month infective endocarditis relapse, and 1-year mortality—were higher in the combination therapy group than the monotherapy group.

Abstract Infective endocarditis (IE) is a relatively rare but life-threatening systemic infection, which remains associated with high morbidity and mortality. The epidemiology of IE has shifted to involve an increasing numbers of older patients with both cardiovascular and other types of prosthetic devices, multiple comorbid conditions often requiring invasive procedures, increasingly virulent pathogens, in particular Staphylococcus aureus, or that can harbour anti-microbial resistance, and an escalation of injection drug use in many areas of the world. In parallel, advancements in diagnostic and therapeutic options have led to complex strategies in patients’ management. Despite these epidemiologic shifts, clinical trials have been rare and most of the evidence guiding IE management derives from expert consensus or analysis of large registries. Because of this, a multi-disciplinary IE team-based approach has been recommended as the standard of care. The aim of this review is to explore the rationale for a multi-disciplinary team-based approach to the management of IE. This approach has proved to be potentially beneficial based on multiple investigations that have evaluated patient outcomes. In addition, implementation strategies, feasibility and options of the team approach have also been highlighted.

Abstract Cardiac implantable electronic device infections (CIEDIs) present substantial challenges for infectious diseases specialists, encompassing diagnosis, management, and complex decision making involving patients, families, and multidisciplinary teams. This review, guided by a common clinical case presentation encountered in daily practice, navigates through the diagnostic process, management strategies in unique scenarios, long-term follow-up, and critical discussions required for CIEDIs.

Abstract Cardiac implantable electronic device infections (CIEDIs) present substantial challenges for infectious diseases specialists, encompassing diagnosis, management, and complex decision-making involving patients, families, and multidisciplinary teams. This review, guided by a common clinical case presentation encountered in daily practice, navigates through the diagnostic process, management strategies in unique scenarios, long-term follow-up, and critical discussions required for CIEDIs.

Abstract Background The Rochester Epidemiology Project (REP) has been used to examine numerous infectious and non-infectious entities in a population-based approach in Olmsted County, Minnesota. To further investigate patterns of enterococcal bloodstream infection (BSI), we used the Expanded Rochester Epidemiology Project (E-REP) to include additional surrounding counties to conduct a retrospective population-based study of adult patients who developed enterococcal BSI, with or without infective endocarditis (IE). Methods The E-REP population under study included eight counties in southeastern Minnesota (including Olmsted County), representing a total population of over 250,000 individuals. Adults (age ≥ 18 years) diagnosed with an initial episode of enterococcal BSI with or without enterococcal IE between January 1, 2018 and December 31, 2022 were included; patients with either polymicrobial BSI with enterococci or a previous bout of enterococcal BSI before the study period were excluded. Cases of enterococcal BSI and IE were identified using ICD-10 codes and underwent complete medical record review. Patient characteristics, microbiology, antibiotic regimens, infectious complications, and outcomes were collected. Results A total of 113 cases of enterococcal BSI were identified over the five-year study period. The age- and sex-adjusted incidence rate of enterococcal BSI was 6.9 per 100,000 person-years, with a significantly higher rate among males than females (Figure 1). BSI incidence rate varied by age, with patients 80 years or older having the highest incidence rate (Figures 1 and 2). Twenty-two cases of enterococcal IE were identified, yielding an overall IE prevalence of 20.8% (Figure 3). The cumulative mortality rate at 12 months was high at 41.7% (Figure 3). Five patients (4.4%) had a relapse of enterococcal BSI, defined as recurrence of BSI after negative follow-up blood cultures and within 12 weeks of the initial BSI. Conclusion This is the first population-based investigation that has focused on the epidemiology and clinical profile of patients with enterococcal BSI and complicating IE in a US population. This included an IE prevalence of 20.8%, which should be considered when evaluating and managing patients with enterococcal BSI. Disclosures Larry M. Baddour, MD, UpToDate, Inc.: Royalty payments (authorship duties).

Abstract Background Prosthetic valves are considered a risk factor for endocarditis however diagnosing prosthetic valve endocarditis (PVE) is complicated by acoustic shadowing on echocardiography. In 2023, the ISCVID published an update to the Duke Criteria (Duke 2023) which intended to increase the sensitivity in diagnosing PVE. The purpose of this study was to examine how TAVR infective endocarditis (TAVR-IE) was diagnosed at our institution 90 Day Mortality Kaplan Meier Curve Methods HERON was utilized to match cases between ACC/STS databases and the EMR at The University of Kansas Health System (TUKHS). Patients with bacteremia occurring after a TAVR were reviewed. Each case was evaluated if they met rejected/possible/definitive endocarditis criteria in the Modified Duke Criteria (Duke 2005) and the Duke 2023 Criteria. To adjudicate the diagnosis, an expert panel reviewed all cases that met definitive endocarditis criteria in any edition of the Duke Criteria. Results A total of 2371 TAVRs were conducted at TUKHS from 2012 to 2023. We identified 146 cases of post procedure bacteremia. We excluded 53 cases leaving 93 in the cohort. Transeophageal echocardiography was utilized in about half of the cases (TTE 73, TEE 45). F-FDG positron emission tomography/CT was done in six patients and Cardiac CT in one patient. Cultures returning with Enterococcus spp (16). viridans group streptococci (15), and Staphylococcus spp. (15) had similar incidence. About half had either atypical organisms (40) on 2005 Duke criteria or polymicrobial growth (7). Definitive criteria were met in 18 and 21 patients for the Duke 2005 and Duke 2023 Criteria respectively. Two cases had minor microbiological criteria upgraded to major in Duke 2023. One case was promoted to definitive endocarditis based on Cardiac CT. Upon adjudication the panel agreed with Duke 2023 Criteria classification. Sensitivity was calculated 85%/100% for Duke 2005 and Duke 2023 Criteria respectively. Kaplan Meier curves calculated no significant difference of 3 month mortality between TAVR patients who had met definitive criteria and those who did not. (Figure #1) Conclusion The 2023 ISCVID Duke Criteria in this study appeared to have superior sensitivity for TAVR-IE when compared to the older Modified Duke Criteria published in 2005. Disclosures Larry M. Baddour, MD, UpToDate, Inc.: Royalty payments (authorship duties). Wissam El Atrouni, MD, ViiV Healthcare: Advisor/Consultant

Abstract Background Staphylococcus lugdunensis (SL) is a coagulase-negative staphylococcus with virulence comparable to that of Staphylococcus aureus. The “skip phenomenon” (SP) is a pattern where blood cultures are intermittently negative before final clearance of bloodstream infection (BSI). SP is well-documented in S. aureus bacteremia but has not been described previously in SL. In this report, we present a cohort with SL BSI and describe its prevalence and their clinical features and outcomes. Methods We conducted a retrospective review of patients with blood cultures positive for SL in samples referred to the Mayo Clinic reference lab between June 2012 and June 2022. We assessed clinical characteristics, including time to positivity, prevalence of the skip phenomenon (defined by a positive culture after 24 hours of negative cultures), patient demographics including Charlson Comorbidity Index, mortality and length of hospital stay. Results We identified 55 patients with SL BSI and 33 of them had enough laboratory data to determine the prevalence of the skip phenomenon. SP was present in 5 of 33 (15.2%) patients. For all patients with SL BSI, the median age was 67 years (interquartile range [IQR] 61-79); mean CCI in the group with SP was 5.6 (standard deviation 2) and those without SP was 5.9 (standard deviation 2.7); median duration of bacteremia was 3 days (IQR 1-4); median hospital length of stay was 14 days (IQR 8-20); and 1-year mortality was 45%. Oxacillin susceptibility was present in 33 of 34 cases. Conclusion A total of 15% of patient cases with SL BSI demonstrated the SP. Recognition of the SP in patients with SL BSI is important as this may impact duration of antibiotic therapy and timing of long-term cardiovascular device placement. Disclosures Larry M. Baddour, MD, UpToDate, Inc.: Royalty payments (authorship duties).