Prosthetic Valve Infective Endocarditis Research Articles

Epidemiology and temporal trends of infective endocarditis between 2006 and 2018 at a tertiary referral center

Abstract Introduction Despite modern diagnostics, targeted antibiotic therapy and surgical treatment the mortality rate of infective endocarditis (IE) remains high. In developed countries both the risk factors and pathogens have changed. Objective and methods In our retrospective study we analyzed the clinical and microbiological characteristics, short- and long-term all-cause mortality, and temporal trends of consecutive patients admitted with IE between 2006 and 2018. Results We included 537 cases in our study, the mean age was 55.9 ± 16.5 years (72.2% male). 325 (60.5%) cases were native left-sided IE, 14 (3%) cases were right-sided IE, 130 (24%) cases were prosthetic valve IE, 62 (11.5%) cases were intracardiac device-related IE and 6 (1%) other cases. The most common microorganisms were Staphylococci (n=175; 33%), including 104 cases of methicillin-sensitive Staphylococcus aureus (MSSA), 27 cases of methicillin-resistant Staphylococcus aureus (MRSA) and 44 cases of coagulase-negative Staphylococci. Streptococcus species were identified in 141 cases (26%), Enterococcus species in 88 cases (16%) and 72 cases (13%) were classified as blood culture-negative IE. In-hospital all-cause mortality was 14%, mortality at six months was 27%, at one-year was 31%, and at five-year was 45%. The incidence of MSSA infections increased over time (p=0.024), while coagulase-negative Staphylococci (p<0.001), and Streptococci (p=0.047) infections decreased. None of the observed mortality rates showed significant change over the study period. Predictors of mortality were advanced age (HR 1.37; p<0.001), impaired renal function (HR: 1.03; p<0.001), reduced ejection fraction on admission (HR 1.38; p<0.001), stroke (HR 1.74; p=0.001), and MRSA infection compared to Streptococci (HR 2.56; p=0.002). Conclusion During the observed 13-year period Staphylococci were the most common pathogens, with an increasing incidence of MSSA infection in our tertiary center. The mortality rate of IE remained high and showed no improvement over time.

Impact of mandatory preoperative dental screening on infective endocarditis in patients undergoing surgical valve replacement

Abstract Background Guidelines recommend preoperative dental screening (PDS) prior to surgical valve replacement (SVR) to reduce risk of prosthetic valve infective endocarditis (IE). However, limited data support these recommendations. Purpose Investigate the effect of mandatory PDS on risk of IE in patients undergoing SVR. Methods A total of 1,207 patients undergoing SVR in Western-Denmark from 2020 to 2022 were included in this observational study. Patients were considered based on two applied PDS practices: mandatory PDS (MPDS), and no routine referral PDS (NPDS). Outcome data were retrieved from Danish registries and adjudicated using medical records. The primary endpoint was incidence of IE. Secondary endpoints were all-cause mortality, and the composite endpoint of IE and all-cause mortality. Key endpoints were also analyzed in a propensity score-matched (PSM) population. Results Of 805 patients in the MPDS, 93% (n=751) underwent subsequent PDS, compared to 5% (n=21) among 402 patients in the NPDS. Patients in the MPDS were older with higher rates of coexisting co-morbidities. During a median follow-up of 2.6 years (interquartile range 1.9-3.2 years), 3.3% (n=40) developed IE. The yearly incidence IE rate was higher in MPDS compared with NPDS (1.5% vs. 0.7%; p=0.08). All-cause mortality rate was higher in the MPDS (2-year mortality of 6.2% vs 2.3%, p=0.02) as well as the composite endpoint (p<0.01). Differences in IE rates, all-cause mortality, but not composite endpoint were abolished in 370 propensity score-matched patients. Conclusion Risk of IE was low regardless of PDS practice. MPDS prior to surgery did not alter the risk of IE or all-cause mortality in patients undergoing left-sided SVR in Denmark.Kaplan-Meier plot

The Evolving Epidemiology of Infective Endocarditis: An Observational Study from Western India

Background: Over the last few decades, the epidemiology and the management of infective endocarditis (IE) is undergoing significant evolution and advancements respectively. Many studies from the developed world and some from India have brought this to light. Objective: To study demography, risk factors, microbiological spectrum, clinical profile, management, and outcome of IE in a tertiary care setup in western India. Materials and Methods: This is a retrospective observational study of 90 patients diagnosed with definite as well as possible IE and admitted to the intensive care units (ICU) and wards in our institute from April 2015 to May 2022. Demographics, signs and symptoms, laboratory results, echocardiography, radiological findings, treatment, and outcomes were studied. Results: 73 (81.1%) were definite and 17 (18.9%) were possible cases of IE. 93.3% cases were community-acquired, 6.7% were hospital acquired. Mean age of the patients was 43.3 + or - 18.8 years. Male: female ratio was 4.3:1. 62.2% had an underlying cardiac illness, with congenital heart disease (CHD) being the most common (18.9%) followed by rheumatic heart disease (RHD) (16.5%). Fever, weight loss, dyspnea, and cough were the common presenting symptoms. 69 (76.7 %) patients had native valve IE, 13 (14.4%) had prosthetic valve IE, 6 (6.7%) had vegetations on the endothelium without involvement of the valves, 2 (2.2%) patients had vegetations on the prosthetic material used for repair of congenital heart defects. About 48% of patients had a history of prior receipt of antibiotics. Blood cultures were positive in 48 (53.3%) patients. Most common valve infected was the mitral valve (MV) and the most common organisms isolated were the viridans group of streptococci (VGS), with penicillin (Pn) MIC <0.5 mcg/ml of all but one isolate. Transesophageal echocardiography (TEE), done in 17 patients, improved the pick-up of abnormal echo findings from 83.3% to 91.1%. Ceftriaxone was the most common antibiotic used. Surgery was done in 22 (24.4%) patients. 67 (74.4%) patients were cured, 14 (15.6%) patients died and 9 (10%) patients were lost to follow-up. Conclusion: The increasing age of patients, absence of any underlying cardiac ailment, the importance of TEE in patients with high suspicion of IE, and the trend towards early surgery were the important aspects highlighted with respect to the changes happening in the field of IE. Almost all the strains of VGS, the most common isolated organisms, retained their sensitivity to Pn and ceftriaxone, making the treatment possible with once-a-day dosing of ceftriaxone monotherapy, highlighting the utilization of outpatient antibiotic therapy (OPAT).

Non-HACEK gram-negative bacilli infective endocarditis: data from a retrospective German cohort study

Abstract Purpose Infective endocarditis caused by non-HACEK gram-negative bacilli (GNB-IE) is rare but associated with significant morbidity and case fatality. Evidence on optimal treatment and management is limited. We aimed to describe the characteristics and management of GNB-IE patients, investigating factors associated with disease acquisition and unfavorable outcomes. Methods We conducted a retrospective descriptive single-center study (tertiary care and referral hospital) between 2015 and 2021, including adult patients with definite GNB-IE. We reviewed demographic, clinical and microbiological data, focusing on predisposing factors, clinical outcomes and 1-year mortality. Results Of 1093 patients with probable or definite IE, 19 patients (median age 69 years) had definite GNB-IE, with an increasing incidence throughout the study period. Median age-adjusted Charlson Comorbidity Index score was 4 points. Prosthetic valve IE (PVIE) was present in 7/19 (37%) patients. Nosocomial acquisition occurred in 8/19 (42%) patients. Escherichia coli and Klebsiella pneumoniae were the most common pathogens. Beta-lactam (BL) based combination therapy was applied in 12/19 (63%) patients (58% BL + fluoroquinolone, 42% BL + aminoglycoside). Cardiac surgery was required in 8/19 (42%) patients (PVIE 71%, native valve IE 25%), primarily for embolism prevention and heart failure. Complications occurred in 14/19 (74%) patients. The in-hospital mortality rate was 21% (4/19); the one-year mortality rate was 44% (7/16). One-year mortality did not significantly differ between patients who underwent cardiac surgery and patients managed with anti-infective treatment alone (p = 0.633). Conclusions GNB-IE affects elderly patients with high comorbidity levels and recent health-care exposure. GNB-IE was associated with high complication rates and high mortality.

Clinical characteristics and outcomes of aortic prosthetic valve endocarditis: comparison between transcatheter and surgical bioprostheses

Abstract Purpose Most data regarding infective endocarditis (IE) after transcatheter aortic valve implantation (TAVI) comes from TAVI registries, rather than IE dedicated cohorts. The objective of our study was to compare the clinical and microbiological profile, imaging features and outcomes of patients with IE after SAVR with a biological prosthetic valve (IE-SAVR) and IE after TAVI (IE-TAVI) from 6 centres with an Endocarditis Team (ET) and broad experience in IE. Methods Retrospective analysis of prospectively collected data. From the time of first TAVI implantation in each centre to March 2021, all consecutive patients admitted for IE-SAVR or IE-TAVI were prospectively enrolled. Follow-up was monitored during admission and at 12 months after discharge. Results 169 patients with IE-SAVR and 41 with IE-TAVI were analysed. Early episodes were more frequent among IE-TAVI. Clinical course during hospitalization was similar in both groups, except for a higher incidence of atrioventricular block in IE-SAVR. The most frequently causative microorganisms were S. epidermidis, Enterococcus spp. and S. aureus in both groups. Periannular complications were more frequent in IE-SAVR. Cardiac surgery was performed in 53.6% of IE-SAVR and 7.3% of IE-TAVI (p=0.001), despite up to 54.8% of IE-TAVI patients had an indication. No differences were observed about death during hospitalization (32.7% vs 35.0%), and at 1-year follow-up (41.8% vs 37.5%), regardless of whether the patient underwent surgery or not. Conclusion Patients with IE-TAVI had a higher incidence of early prosthetic valve IE. Compared to IE-SAVR, IE-TAVI patients underwent cardiac surgery much less frequently, despite having surgical indications. However, in-hospital and 1-year mortality rate was similar between both groups.

Three cases of Cutibacterium avidum prosthetic valve infective endocarditis at a single heart center

ObjectiveTo resolve an exceptional clustering of Cutibacterium avidum prosthetic valve infective endocarditis (IE) at a single heart center. MethodsDuring a period of 21 months, three patients experienced C. avidum bacteremia 24-128 days after aortic valve replacement. Operative procedures and electronic prescriptions of antimicrobials were surveyed, and bacterial isolates were genome sequenced. ResultsThe prosthetic valves were inserted by separate surgical teams. In one case, echocardiographic confirmation of IE was not achieved until 4 months after the first positive blood culture, but the causative agents were irrefutably documented in all cases by culture, or amplification of bacterial deoxyribonucleic acid, from removed prosthetic material. Whole-genome sequencing clustered isolates to a distinctive subgroup of the species but did not suggest inter-patient transmission of isolates. ConclusionsDespite vigorous sampling of blood and tissue, detection of C. avidum was not unconditional, neither by culture nor polymerase chain reaction test. The causative agent is likely underreported and should be meticulously searched for in culture-negative prosthetic valve endocarditis.

Acute heart failure in patients with valvular infective endocarditis: a one-year consecutive cohort from a Spanish tertiary centre

Abstract Funding Acknowledgements None. Background Infective endocarditis (IE) is associated with substantial morbidity and mortality. Acute decompensated heart failure (AHF) is a frequent complication of IE and it is often an indication for urgent cardiac surgery. Purpose The aim of this study was to describe clinical data and short term outcomes of patients admitted for valvular IE complicated with AHF. Methods We collected data from all the patients with IE admitted or referred to our Spanish tertiary centre from September 1st, 2022 to August 31st, 2023. Patients with non-valvular IE were not included. Results Two patients did not consent to participate in the study. 87 consenting patients were included. Of them, 38 (44%) presented with AHF, of whom 14 (16.1%) had acute pulmonary oedema, and 6 (6.9%) suffered cardiogenic shock. Mean age was 67.4 years old in the AHF group vs 64.0 in patients without AHF (non significant), 74% of male sex in both groups, Charlson Comorbidity Index of 4.9 vs 5.6 points (n.s.); prosthetic-valve endocarditis was more frequent in the AHF group compared to patients without AHF (42% vs 28%, p < 0.05). Urgent cardiac surgery was indicated in 91% of patients with AHF vs 44% of patients without heart failure (p < 0.01); when indicated, surgery was eventually performed in 65% vs 57% of the patients (n.s.). In AHF patients with surgical indication, in-hospital mortality rate was significantly higher in those that did not undergo surgery (64% vs 16%, p < 0.01). Compared to native-valve IE, prosthetic-valve IE was associated with higher rates of AHF (42% vs 28%, p < 0.05). In-hospital mortality rate was significantly higher in AHF patients (33.3% vs 3.0%, p < 0.01). Acute pulmonary oedema and cardiogenic shock patients had the highest in-hospital mortality (respectively, 43% and 67%). Similarly, mortality rate 30 days after hospital discharge was higher in the AHF group (16.0% vs 6.3%, p < 0.05). Conclusions In this population, presentation with AHF was associated with worse short-term outcomes. Surgery was indicated in the majority of AHF patients, and not performing it was associated with worse outcome.

Suppressive antibiotic therapy for infectious endocarditis

ObjectivesSuppressive antibiotic therapy (SAT) is a long-term antibiotic strategy at times applied when an indicated surgical management of infective endocarditis (IE) is not possible. Our aim was to describe the characteristics and outcomes of patients having received SAT for IE. MethodsWe conducted a retrospective, observational study at Strasbourg University Hospital, France between January 2020 and May 2023. We reviewed all medical files taken into consideration at weekly meetings of the local Multidisciplinary Endocarditis Team (MET) during the study period. We included patients having received SAT following the MET evaluation. The primary endpoint was all-cause mortality at most recent follow-up. Secondary endpoints included all-cause mortality at 3 and 6 months, infection relapse, and tolerance issues attributed to SAT. ResultsThe MET considered 251 patients during the study time, among whom 22 (9 %) had received SAT. Mean age was 77.2 ± 12.3 years. Patients were highly comorbid with a mean Charlson index score of 6.6 ± 2.5. Main indication for SAT was surgery indicated but not performed or an infected device not removed (20/22). Fourteen patients had prosthetic valve IE, including 9 TAVIs. Six patients had IE affecting cardiac implantable electronic devices. Staphylococcus aureus and enterococci were the main bacteria involved (6/22 each). Median follow-up time was 249 days (IQR 95–457 days). Mortality at most recent follow-up was 23 % (5/22). Three patients (14 %) presented tolerance issues attributed to SAT, and two patients suffered late infectious relapse. ConclusionMortality at most recent follow-up was low and tolerance issues were rare for patients under SAT, which might be a palliative approach to consider when optimal surgery or device removal is not possible.

External Validation of the 2023 Duke-International Society for Cardiovascular Infectious Diseases Diagnostic Criteria for Infective Endocarditis.

The 2023 Duke-International Society of Cardiovascular Infectious Diseases (ISCVID) criteria for infective endocarditis (IE) were introduced to improve classification of IE for research and clinical purposes. External validation studies are required. We studied consecutive patients with suspected IE referred to the IE team of Amsterdam University Medical Center (from October 2016 to March 2021). An international expert panel independently reviewed case summaries and assigned a final diagnosis of "IE" or "not IE," which served as the reference standard, to which the "definite" Duke-ISCVID classifications were compared. We also evaluated accuracy when excluding cardiac surgical and pathologic data ("clinical" criteria). Finally, we compared the 2023 Duke-ISCVID with the 2000 modified Duke criteria and the 2015 and 2023 European Society of Cardiology (ESC) criteria. A total of 595 consecutive patients with suspected IE were included: 399 (67%) were adjudicated as having IE; 111 (19%) had prosthetic valve IE, and 48 (8%) had a cardiac implantable electronic device IE. The 2023 Duke-ISCVID criteria were more sensitive than either the modified Duke or 2015 ESC criteria (84.2% vs 74.9% and 80%, respectively; P < .001) without significant loss of specificity. The 2023 Duke-ISCVID criteria were similarly sensitive but more specific than the 2023 ESC criteria (94% vs 82%; P < .001). The same pattern was seen for the clinical criteria (excluding surgical/pathologic results). New modifications in the 2023 Duke-ISCVID criteria related to "major microbiological" and "imaging" criteria had the most impact. The 2023 Duke-ISCVID criteria represent a significant advance in the diagnostic classification of patients with suspected IE.

A Bayesian network-based approach for identifying risk factors and predicting ischemic stroke in infective endocarditis patients.

This study aimed to seek the risk factors and develop a predictive model for ischemic stroke (IS) in patients with infective endocarditis (IE) utilizing a Bayesian network (BN) approach. Data were obtained from the electronic medical records of all adult patients at three hospitals between 1 January 2018, and 31 December 2022. Two predictive models, logistic regression and BN, were used. Patients were randomly assigned to the training and test sets in a 7:3 ratio. We established a BN model with the training dataset and validated it with the testing dataset. The Bayesian network model was built by using the Tabu search algorithm. The areas under the receiver operating characteristic curve (AUCs), calibration curve, and decision curve were used to evaluate the prediction performance between the BN and logistic models. A total of 542 patients [mean (SD) age, 49.6 (15.3) years; 137 (25.3%) female] were enrolled, including 151 (27.9%) with IS and 391 (72.1%) without IS. Hyperlipidemia, hypertension, age, vegetation size (>10 mm), S. aureus infection, and early prosthetic valve IE were closely correlated with IS. The BN models outperformed the logistic regression in training and testing sets, with accuracies of 76.06% and 74.1%, AUC of 0.744 and 0.703, sensitivities of 25.93% and 20.93%, and specificities of 96.27% and 90.24%, respectively. The BN model is more efficient than the logistic regression model. Therefore, BN models may be suitable for the early diagnosis and prevention of IS in IE patients.

963. External Validation of the 2023 Duke - International Society for Cardiovascular Infectious Diseases (ISCVID) Diagnostic Criteria for Infective Endocarditis (IE)

Abstract Background The 2023 Duke-ISCVID criteria for IE were recently introduced to improve classification of IE for research and clinical purposes (Table 1). We compared the diagnostic accuracy of the new criteria with the 2000 modified Duke criteria, the 2015 European Society of Cardiology (ESC) criteria and a clinically adjudicated reference standard by a panel of international experts on IE.Table 1:Overview of changes in criteria from 2000 modified Duke to 2023 Duke-ISCVIDAdapted from: Fowler et al, Clinical Infectious Diseases, 2023 Methods The study population consisted of consecutively enrolled patients suspected to have IE and discussed by the IE team of the Amsterdam University Medical Center (AMC) between October 2016 and March 2021. A panel of international experts on IE assigned a final diagnosis, which served as the reference standard. We compared the definite classification of the 2023 Duke-ISCVID criteria against this reference standard. We also evaluated accuracy of the new criteria, excluding data obtained from cardiac surgery and pathology (“Clinical Criteria”). Lastly, we quantified the added value of the proposed changes to the criteria, and compared the 2023 Duke-ISCVID to previous criteria using the McNemar test. We performed sensitivity analyses in patients who underwent cardiac surgery and patients who underwent TEE. Results 595 patients with suspected IE were included, of whom 399 (67%) were adjudicated as having IE. 111 patients (19%) had prosthetic valve IE, 48 (8%) had cardiac implantable electronic device IE. The 2023 Duke-ISCVID criteria were more sensitive than the modified Duke or ESC criteria (84.2 vs 74.9 vs 80%,respectively, p &amp;lt; 0.001 for ISCVID vs ESC criteria) without significant loss of specificity (Table 2). After excluding cardiac surgery/pathology results, the 2023 Duke-ISCVID Clinical Criteria also had significantly better sensitivity than the modified Duke and ESC criteria, again without losing specificity. The changes in the 'major microbiological' and 'imaging' criteria had the most impact (Figure 1). Findings were robust in sensitivity analyses (Table 3). When classifying ‘definite’ and ‘possible’ IE as a positive test, the 2023 Duke-ISCVID criteria had 99% sensitivity compared to the reference standard, but specificity decreased to 21%.Table 2:Diagnostic accuracy of modified Duke, ESC and Duke-ISCVID criteria Sensitivity and specificity are against the reference standard (adjudication panel). The Clinical Criteria classification is the Duke-ISCVID classification when results from surgery or post-mortem studies are not used to determine classification.Table 3:Sensitivity analyses of accuracy of Duke-ISCVID criteria In the Definite + Possible analysis, patients with possible IE according to the Duke-ISCVID criteria were also considered as having IE. All comparisons are against the reference standard (adjudication panel). Conclusion In this cohort, the 2023 Duke-ISCVID criteria represent a significant advance in the diagnostic classification of patients suspected of IE. Added value of new Duke-ISCVID criteria compared to modified Duke criteria Each point (red square for sensitivity, blue circle for specificity) provides the diagnostic accuracy measure for the 2000 modified Duke Criteria with addition of a specific change from the Duke-ISCVID criteria. The horizontal bars represent the 95% confidence interval for the point estimate. The top points represent the modified Duke criteria without addition, the bottom points are the complete Duke-ISCVID criteria. Disclosures Larry M. Baddour, MD, Boston Scientific: Advisor/Consultant|Roivant Sciences: Advisor/Consultant Arnold S. Bayer, MD, Akagera Medicines: Grant/Research Support|ContraFect Corporation: Grant/Research Support Emanuele Durante Mangoni, MD,, PhD, Advanz pharma: Advisor/Consultant|Advanz pharma: Grant/Research Support|Advanz pharma: Honoraria|Angelini: Grant/Research Support|Angelini: Honoraria|Genentech: Advisor/Consultant|Genentech: Board Member|Genentech: Honoraria|Infectopharm: Grant/Research Support|Menarini: Board Member|Menarini: Honoraria|Pfizer: Advisor/Consultant|Pfizer: Board Member|Pfizer: Grant/Research Support|Pfizer: Honoraria|Roche: Advisor/Consultant|Roche: Board Member|Roche: Honoraria Thomas L. Holland, MD, Aridis: Advisor/Consultant|Basilea Pharmaceutica: Advisor/Consultant|Karius: Advisor/Consultant|Lysovant: Advisor/Consultant Adolf W. Karchmer, MD, Karius: Grant/Research Support|Up To Date: Honoraria Vance G. Fowler, MD, MHS, Amphliphi Biosciences, Integrated Biotherapeutics; C3J, Armata, Valanbio; Akagera, Aridis, Roche, Astra Zeneca: Advisor/Consultant|Genentech, Regeneron, Deep Blue, Basilea, Janssen;: Grant/Research Support|Infectious Diseases Society of America: Honoraria|MedImmune, Allergan, Pfizer, Advanced Liquid Logics, Theravance, Novartis, Merck; Medical Biosurfaces; Locus; Affinergy; Contrafect; Karius;: Grant/Research Support|Novartis, Debiopharm, Genentech, Achaogen, Affinium, Medicines Co., MedImmune, Bayer, Basilea, Affinergy, Janssen, Contrafect, Regeneron, Destiny,: Advisor/Consultant|Sepsis diagnostic: Patent pending|UpToDate: Royalties|Valanbio and ArcBio: Stock Options

Impact of mandatory preoperative dental screening on post-procedural risk of infective endocarditis in patients undergoing transcatheter aortic valve implantation: a nationwide retrospective observational study

Guidelines recommend preoperative dental screening (PDS) prior to cardiac valve surgery, to reduce the incidence of prosthetic valve infective endocarditis (IE). However, limited data support these recommendations, particular in patients undergoing transcatheter aortic valve implantation (TAVI). We aimed to investigate the effect of mandatory PDS on risk of IE in patients undergoing TAVI. In this observational study, a total of 1133 patients undergoing TAVI in Western-Denmark from 2020 to 2022 were included. Patients were categorized based on two implemented PDS practices: mandatory PDS (MPDS group), and no referral for PDS (NPDS group). Outcome data were retrieved from Danish registries and confirmed using medical records. The primary outcome was incidence of IE. Secondary outcomes were all-cause mortality and composite outcome of all-cause mortality and IE. Of 568 patients in the MPDS group 126 (22.2%) underwent subsequent oral dental surgery, compared to 8 (1.4%) among 565 patients in the NPDS group. During a median follow-up of 1.9 years (interquartile range 1.4-2.5 years), 31 (2.7%) developed IE. The yearly incidence IE rate was 1.4% (0.8-2.3) and 1.5% (0.8-2.4) in MPDS and NPDS, respectively, p=0.86. All-cause mortality rates were similar between groups (estimated 2-year overall mortality of 6.7% (4.8-9.2) vs. 4.7% (3.2-6.9), MPDS and NPDS, respectively, p=0.15). Consistent findings were found in 712 propensity score-matched patients. Mandatory PDS did not demonstrate reduced risk of IE or all-cause mortality compared to targeted PDS in patients undergoing TAVI. The funder had no role in the study design, data management, or writing.

Prognosis of prosthetic valve infective endocarditis due to Streptococcus spp., a retrospective multi-site study to assess the impact of antibiotic treatment duration.

The duration of antibiotic treatment for prosthetic valve endocarditis caused by Streptococcus spp. is largely based on clinical observations and expert opinion rather than empirical studies. Here we assess the impact of a shorter antibiotic duration. To assess the impact of antibiotic treatment duration for streptococcal prosthetic valve endocarditis on 12-month mortality as well as subsequent morbidity resulting in additional cardiac surgical interventions, and rates of relapse and reinfection. This retrospective multisite (N= 3) study examines two decades of data on patients with streptococcal prosthetic valve endocarditis receiving either 4 or 6 weeks of antibiotics. Overall mortality, relapse, and reinfection rates were also assessed for the entire available follow-up period. The sample includes 121 patients (median age 72 years, IQR [53; 81]). The majority (74%, 89/121) received a ß-lactam antibiotic combined with aminoglycoside in 74% (89/121, median bi-therapy 5 days [1; 14]). Twenty-eight patients underwent surgery guided by ESC-guidelines (23%). The 12-month mortality rate was not significantly affected by antibiotic duration (4/40, 10% in the 4-week group vs 3/81, 3.7% in the 6-week group, p=0.34) or aminoglycoside usage (p=0.1). Similarly, there were no significant differences between the 2 treatment groups for secondary surgical procedures (7/40 vs 21/81, p=0.42), relapse or reinfection (1/40 vs 2/81 and 2/40 vs 5/81 respectively). Our study found no increased adverse outcomes associated with a 4-week antibiotic duration compared to the recommended 6-week regimen. Further randomized trials are needed to ascertain the optimal duration of treatment for streptococcal endocarditis.

Contemporary profile of infective endocarditis in young patients in the era of ageing population: a comparative study

Abstract Aim The aim of the study is to describe the main differences in epidemiological characteristics, clinical features and prognosis between IE patients aged &amp;lt;50 and ≥50 years. Methods A total of 1935 episodes of IE were prospectively recruited at three tertiary centres from 1996 to 2022. Patients were classified into two groups: &amp;lt;50 years (n=333, median age 40 [IQR 33-45] and ≥50 years (n=1602, median age 71 [IQR 64-78]). Variables related to epidemiology, microbiology, echocardiography and outcomes among both groups were analysed. Results The proportion of male patients was higher in those &amp;lt;50 years (73.9% vs 64%; p&amp;lt;0.001). Patients aged ≥50 years had more comorbidities. Time to diagnosis was longer in this group of patients (6.2 ± 1.5 vs 21.7 ± 14.12 days; p&amp;lt;0.001). Proportion of community-acquired IE was higher in &amp;lt;50-year episodes (64.4% vs 81%; p&amp;lt;0.001). Intravenous drug use (IVU) was significantly more frequent in younger patients (22.6% vs 0.5%; p&amp;lt;0.001). Likewise, tricuspid native valve IE was more common in patients &amp;lt;50 years old (16.6% vs 4%; p&amp;lt;0.001). Congenital heart disease (17.2% vs 2.7%; p&amp;lt;0.001) and mitral valve prolapse (6.3% vs 3.8%; p=0.041) were more frequent in patients aged&amp;lt;50 years. Conversely, prosthetic valve IE (38.4% vs 20.7%; p&amp;lt;0.001) was more common in patients &amp;gt;50 years. Streptococcus bovis (0.9% vs 5.6%; p&amp;lt;0.001), enterococci (3% vs 12.6%; p=0.000), coagulase-negative staphylococci (9.9% vs 18.4%; p&amp;lt;0.001) and gram-negative bacilli (1.2% vs 3.5%; p=0.028) infections were more frequent in ≥50-year adults, while the incidence of Streptococcus viridans (21.9% vs 10.7%; p&amp;lt;0.001) and HACEK (1.2% vs 0.3%; p=0.03) infections was higher in the &amp;lt;50-year group. Staphylococcus aureus IE was similar between the two groups (23.7% vs 19.4%; p=0.074). The presence of vegetations (87.4% vs 80.9%; p=0.005), as well as severe new valve regurgitation (42% vs 30.8%; p&amp;lt;0.001) were more often found in &amp;lt;50-year patients. Acute heart failure (44.1% vs 59.5%; p&amp;lt;0.001), acute kidney failure (27.3% vs 47.5%; p&amp;lt;0.001) and septic shock (15.3% vs 20.9%; p=0.02) were more frequent in &amp;gt;50-year group. No differences in frequency of cardiac surgery among both groups were found (61.9% vs 57.6%; p=0.147). In-hospital mortality was significantly higher in ≥50-year patients (15.6% vs 29.2%; p&amp;lt;0.001). Mortality remained higher in ≥50-year adults who underwent cardiac surgery (12.4% vs 23.3%; p=0.001) as well as those who did not undergo surgery (20.5% vs 37.2%; p&amp;lt;0.001). Conclusions Patients aged &amp;lt;50 years diagnosed with IE were more frequently male, and had a higher proportion of community-acquired infections. Congenital heart disease, mitral valve prolapse and IVU were more frequent in &amp;lt;50-year adults. Streptococcus viridans infections were more frequent in this group of patients. In-hospital complications and mortality were lower compared to older patients, regardless of whether they underwent cardiac surgery.

Performance of 18F-FDG PET/CT in the diagnosis of endocarditis

Abstract Background Infectious endocarditis (IE) remains a diagnostic challenge that requires a combination of clinical, microbiology, and imaging clues. Usefulness of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) in the diagnostic algorithms has been demonstrated. However, performances of 18F-FDG PET/CT vary greatly between studies and types of IE. 18F-FDG PET/CT may have a better sensitivity for prosthetic valve IE (PVE) than for native valve IE (NVE) or cardiac implantable electronic devices IE (CIED-IE). Purpose Define the performance of 18F-FDG PET/CT after echocardiography in the diagnosis of all types of IE in our institution. Methods This hybrid study was conducted at a university hospital from January 2014 to June 2022 (retrospective cohort: 2014-17 and prospective cohort: from 2018 onwards). Adult patients with a suspected valvular or CIED-IE were included. Realization of 18F-FDG PET/CT was left at the discretion of the treating physician or by an endocarditis-team that was established in 2018. 18F-FDG PET/CT analysis were performed nuclear medicine physicians and radiologists (when the CT was contrast-enhanced), based on visual interpretation. The final diagnosis of possible or definite IE was defined by the endocarditis team according to European Society of Cardiology 2015 modified Duke criteria. Results During the study period, 280 18F-FDG PET/CT with interpretable intracardiac results were performed for a clinical suspicion of IE in 247 patients. A final IE diagnosis was retained for 116 episodes (41%; 81 definite and 35 possible IE), among which 102 valvular (59 NVE and 44 PVE) and 20 CIED-IE. 18F-FDG PET/CT showed radiologic signs of endocarditis in 60 episodes (21%) with an overall specificity, sensitivity, positive and negative predictive values (PPV, NPV) of 97.6%, 48.3%, 93.3%, and 72.7%, respectively. This led to an overall accuracy of 77.1% and between 80 to 85% when looking at specific types of IE. Performances of 18F-FDG PET/CT for each type of IE are shown in Figure 1. Addition of 18F-FDG PET/CT to the modified Duke criteria reclassified the diagnosis in 37 cases: from possible/rejected IE to definite IE in 25 cases (21.5%) and from rejected IE to possible IE in 12 cases (10.3%) (Figure 2). Figure 2 shows a Shankey diagram of classification of episodes by clinical Duke criteria without 18F-FDG PET/CT results (left side), clinical Duke criteria with 18F-FDG PET/CT results (center) and final diagnosis retained by clinicians (right side). Conclusion Use of 18F-FDG PET/CT in a multimodal diagnostic approach led to an acceptable accuracy for all types of IE in our center. Signs of endocarditis on 18F-FDG PET/CT should be interpreted as confirmatory, while absence of sign do not efficiently rule out this diagnosis. In this cohort, 18F-FDG PET/CT helped to reclassify 15.9% of possible or rejected IE.Performance of 18F-FDG PET/CTShankey diagram of IE classification

Abstract 12025: Utility of Intracardiac Echocardiography for Prosthetic Valve Infective Endocarditis and Cardiovascular Device-Related Infection: A Contemporary Systematic Review

Introduction: Infective endocarditis (IE), particularly prosthetic valve endocarditis (PVE) and cardiac device-related endocarditis (CDIE), presents significant diagnostic challenges. The efficacy of intra-cardiac echocardiography (ICE) for diagnosing IE and assessing intra-cardiac infections when transesophageal echocardiography (TEE) is contraindicated, is not extensively studied. Methods: We searched six databases, including PubMed, Embase, Scopus, Ovid, Science Direct, and Web of Science, for articles published between September 2002 and November 2022, related to the utility of ICE in IE. Eligibility screening followed the search. Results: From the 12 identified studies discussing ICE for IE diagnosis, ten cases of IE were highlighted in nine reports, and three cohort studies included 236 patients without individual patient details. ICE was not used in any native valve IE case. Predominantly male patients (90%) had a median age of 42 years, developing endocarditis 2.5 years post initial cardiac procedure. The most common microorganisms identified were Staphylococcus species. ICE proved beneficial in various scenarios, particularly PVE and CDIE, especially when echocardiography studies were inconclusive or contraindicated. As an alternative to TEE, ICE offers clear visualization of right heart structure, guiding interventions such as pacemaker lead extractions. It excels in detecting device lead abnormalities and small vegetations in CDIE cases, supporting risk stratification and preparation for infected device extraction. Notably, all PVE cases involved bioprosthetic valves, affecting various heart structures and valves. Conclusion: This systematic review highlights ICE as an adjunct imaging modality in IE, especially in PVE and CDIE when TEE is contraindicated. Preliminary data suggest its valuable role during intracardiac lead extractions.

Case report: a missed case of chronic Q fever infective endocarditis demonstrating the ongoing diagnostic challenges

Diagnosis of chronic Q fever is often difficult for clinicians, particularly in the presence of a second pathology. In addition to the chronic constitutional symptoms, the most common manifestations of chronic Q fever include infective endocarditis and endovascular infection. We describe a case of prosthetic valve infective endocarditis caused by both Streptococcus sanguinis and Coxiella burnetti on a background of a previous aortic graft and bioprosthetic aortic valve replacement 2 years earlier. The diagnosis of chronic Q fever infective endocarditis was delayed because the significance of the abnormal valve histology from the patient’s previous surgery was initially overlooked. It was only after the patient had relapsed on appropriate therapy for the S. sanguinis prosthetic valve endocarditis that a subsequent review of the operative valve histology, along with the patient’s epidemiological risk factors, led to consideration of an additional culture-negative cause for infective endocarditis. Histological examination of the valve tissue had shown exophytic fibrin vegetations and acute inflammation. Further clinical assessment revealed previous exposure to Q fever and C. burnetti DNA was detected via polymerase chain reaction on the valve tissue. Q fever infective endocarditis must be considered if valves are inflamed or have vegetations with a subsequent negative culture. It should also still be considered in the presence of an alternative bacteraemia if the patient has risk factors for exposure.

Clinical and morphological features of infective endocarditis of native and prosthetic heart valves

Aim. To evaluate clinical and morphological data of infective endocarditis (IE) of native and prosthetic heart valves.Material and methods. This retrospective cohort study included 354 patients that had signs of IE according to pathological study of surgical material from native valves and prosthetic heart valves. The patients were divided into two groups: the first group included patients with native valve IE (n=328), while the second group — with prosthetic valve IE (n=26).Results. Among patients with native valve IE, aortic (AV) and mitral valve (MV) IE was recorded in 67,6% and 20,7%, respectively. In the group of patients with prosthetic IE, AV IE also predominated — 57,7% vs 26,9% in MV IE. In the majority of patients in the first group, secondary IE was detected (68,9%). The development of IE in the presence of bicuspid AV (BAV), degenerative AV disease, and rheumatic valve disease was revealed in 40,7%, 31,4% and 6,7%, respectively. In the group of patients with native valve IE, subactive IE was most often detected — in 38,4%, while in 7,1% — signs of process remission were detected. In the group of patients with prosthetic valve IE, IE with moderate activity was detected more often than in the group of patients with native valve IE (42,3% vs 26,8%, p=0,042). In the group of patients with prosthetic valve IE, the presence of colonies of microorganisms and neutrophilic infiltration in the histological material was somewhat more common, while in patients with native valve IE there was a tendency towards a higher percentage of necrosis in the studied material (42,4% vs 38,5%, p&gt;0,05).Conclusion. This work confirms changes in the epidemiological characteristics of patients with IE. A high frequency of subactive forms of IE was noted according in patients with native valve IE, which requires individual approach to antibacterial therapy depending on the pathomorphological IE activity.

Oral streptococcal infective endocarditis among individuals at high risk following dental treatment: a nested case-crossover and case-control study

It is not clear whether Viridans Group Streptococcal Infective Endocarditis (VGS-IE) among individuals at high risk is more frequent following bacteraemia caused by invasive dental procedures (IDPs) than after daily bacteraemia caused by chewing and tooth brushing. The aim of this nested study was to assess if VGS-IE was temporally associated with IDPs in a national cohort of individuals at high risk. This nested case-control and case-crossover study was based on a Swedish national cohort study of 76,762 individuals at high risk of IE due to complex congenital heart disease, prosthetic heart valve or previous IE. Participants were living in Sweden between July 1st, 2008 and January 1st, 2018. The frequency of IDPs during the 3 months before VGS-IE was calculated and compared to controls (sampled 1:10). A case-crossover study was conducted to account for residual confounders. Participants were identified using the national patient register, and IDPs were identified using the national dental health register. 98,247 IDPs were carried out in the cohort during the study period: 624 occasions of oral surgery, 44,190 extractions and 53,433 sessions of subgingival scaling. The study could not confirm that IDPs were more common among cases (4.6%) than controls (4.1%), OR=1.22 [95% Confidence Interval (CI) 0.64-2.3], or during case- (3.3%) than reference periods (3.8%), OR=0.89 [95% CI: 0.68-1.17]. Restricting the analysis to the period when cessation of antibiotic prophylaxis for the prevention of IE in Swedish dentistry was recommended, from the 1st of October 2012 to the 1st of January 2018, did not alter the results of the case-control study: OR 0.64, 95% CI: 0.20-2.09, or the case-crossover study: OR 0.58, 95% CI: 0.15-2.19. The study could not confirm that VGS-IE is associated with IDPs among individuals at high risk. A study with larger sample size could clarify whether there is a lack of association. The finding of a small (<5%) proportion of cases temporally associated with IDPs is similar to that of the previous large-scale study on IDPs and VGS-IE. Funding was provided by the Board of doctoral education at Karolinska Institutet, the Public Health Agency of Sweden, Folktandvården Stockholm AB, Steering Group for Collaborative Odontological Research at Karolinska Institutet and Stockholm City County, and the Swedish Dental Association.

Enterococcal Prosthetic Valve Infective Endocarditis Presenting as Complete Heart Block with Intramyocardial Abscess Causing Asystolic Cardiac Arrest

The extension of an intracardiac abscess causing complete heart block is a rare complication of infective endocarditis that is associated with a high mortality. Early identification of conduction abnormalities and a low threshold for suspecting infective endocarditis is crucial to provide prompt management to prevent intracardial extension of infection. We report a case of a patient presenting with complete heart block in the setting of profound hyperkalemia, and was then found to have enterococcal prosthetic valve endocarditis, which was complicated by an intracardiac aortic root abscess which led to asystolic cardiac arrest. The development of heart block in endocarditis serves as a marker for poor prognosis and can signify progression of infection. Management therefore requires immediate pacing, antibiotic delivery to lessen infectious burden, and evaluation for consideration of surgical options such as valve replacement. It is therefore recommended for patients with endocarditis complicated by conduction abnormalities or intracardial abscesses to be treated by a multi-disciplinary team consisting of cardiologists, cardiothoracic surgeons, and infectious disease specialists.