Streptococcus agalactiae infective endocarditis in Canada: a multicenter retrospective nested case control analysis

Background Infective endocarditis (IE) caused by Streptococcus agalactiae (GBS) is increasingly reported and associated with an aggressive course and high mortality rate. Existing literature on GBS IE is limited to case series; we compared the characteristics of patients with GBS IE to patients with GBS bacteremia without IE to identify risk factors for development of IE. Methods A nested case–control study in a cohort of adult patients with GBS bacteremia over a 18-year period was conducted across seven centres in three Canadian cities. A chart review identified patients with possible or definite IE (per Modified Duke Criteria) and patients with IE were matched to those without endocarditis in a 1:3 fashion. Multivariate analyses were completed using logistic regression. Results Of 520 patients with GBS bacteremia, 28 cases of possible or definite IE were identified (5.4%). 68% (19/28) met criteria for definite IE, surgery was performed in 29% (8/28), and the overall in-hospital mortality rate was 29% (8/28). Multivariate analysis demonstrated that IE was associated with injection drug use (OR = 19.6, 95% CI = 3.39–111.11, p = 0.001), prosthetic valve (OR = 11.5, 95% CI = 1.73–76.92, p = 0.011) and lack of identified source of bacteremia (OR = 3.81, 95% CI = 1.24–11.65, p = 0.019). Conclusions GBS bacteremia, especially amongst people who inject drugs, those with prosthetic valves, and those with no apparent source of infection, should increase clinical suspicion for IE.

Multimodality Imaging in the Diagnosis of Prosthetic Valve Endocarditis: A Brief Review

Infective endocarditis is a common and treatable condition that carries a high mortality rate. Currently the workup of infective endocarditis relies on the integration of clinical, microbiological and echocardiographic data through the use of the modified Duke criteria (MDC). However, in cases of prosthetic valve endocarditis (PVE) echocardiography can be normal or non-diagnostic in a high proportion of cases leading to decreased sensitivity for the MDC. Evolving multimodality imaging techniques including leukocyte scintigraphy (white blood cell imaging), 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), multidetector computed tomographic angiography (MDCTA), and cardiac magnetic resonance imaging (CMRI) may each augment the standard workup of PVE and increase diagnostic accuracy. While further studies are necessary to clarify the ideal role for each of these imaging techniques, nevertheless, these modalities hold promise in determining the diagnosis, prognosis, and care of PVE. We start by presenting a clinical vignette, then evidence supporting various modality strategies, balanced by limitations, and review of formal guidelines, when available. The article ends with the authors' summary of future directions and case conclusion.

Comparison of Staphylococcus Aureus Endocarditis Risk Factors With Bacteremia

Introduction: Infective endocarditis (IE) is endothelial damage of the endocardium, which is caused by infection. The etiologic agents' highest mortality and morbidity rates are associated with staphylococcus aureus (S. aureus). Accordingly, the knowledge of different risk factors for IE caused by the S. aureus is necessary.Material and methods: This study is an observational-analytical retrospective cohort study on 139 patients with staphylococcus aureus bacteremia (SAB), who referred to a cardiac center during 2011-2019. This study aimed to evaluate the risk factors in 48 patients with staphylococcus aureus endocarditis, who were selected from139 patients with S. aureus bacteremia. Results: The mean age (±SD) of the patients is 56.61 (±16.58), and85 (61.2%) persons are male. Forty-eight patients (34.5%) are diagnosed with staphylococcus aureus endocarditis regarding Duke criteria. In this study, the following risk factors were significantly associated with S. aureus endocarditis: age (p=0.003), long-term bacteremia (p=0.041), prosthetic heart valve (p=0.016), pre-existing IE (p=0.048), and embolic events (p=0.039).Conclusion: According to the findings, a significant number of patients with staphylococcus aureus bacteremia (SAB) have IE with different risk factors. Future studies with a larger sample size are recommended to detect IE risk factors.

Role of Multimodal Imaging in Patients With Suspected Infections After the Bentall Procedure

Purpose: This study aimed to assess the diagnostic performances of multimodal imaging [i.e., white blood cell single-photon emission computed tomography/CT (99mTc-HMPAO-WBC SPECT/CT) and 18-fluoride-fluorodeoxyglucose positron emission tomography/CT ([18F]FDG PET/CT)] in patients with suspected infection after the Bentall procedure, proposing new specific diagnostic criteria for the diagnosis.Methods: Between January 2009 and December 2019, we selected within a cardiovascular infections registry, 76 surgically treated patients (27 women and 49 men, median 66 years, and range 29–83 years). All the patients underwent molecular imaging for a suspected infection after the replacement of the aortic valve and ascending aorta according to the Bentall procedure. We analyzed 98 scans including 49 99mTc-WBC and 49 [18F]FDG PET/CT. A total of 22 patients with very early/early suspected infection (<3 months after surgery) were imaged with both the techniques. Positive imaging was classified according to the anatomical site of increased uptake: to the aortic valve (AV), to both the AV and AV tube graft (AVTG) or to the TG, to surrounding tissue, and/or to extracardiac sites (embolic events or other sites of concomitant infection). Standard clinical workup included in all the patients having echocardiography/CT, blood culture, and the Duke criteria. Pretest probability and positive/negative likelihood ratio were calculated. Sensitivity and specificity of 99mTc labeled hexamethylpropylene amine oxime-WBC SPECT/CT (99mTc-HMPAO-WBC SPECT/CT) and [18F]FDG PET/CT imaging were calculated by using microbiology (n = 35) or clinical follow-up (n = 41) as final diagnosis. 99mTc-HMPAO-WBC scintigraphy and [18F]FDG PET/CT findings were compared with 95% CIs by using the McNemar test to those of echocardiography/CT, blood culture, and the Duke criteria.Results: Sensitivity, specificity, and accuracy of 99mTc-HMPAO-WBC were 86, 92, and 88%, respectively, with a slightly higher sensitivity for tube graft infection (TGI) as compared to isolated AV and combined AVTG. Overall, sensitivity, specificity, and accuracy of [18F]FDG PET/CT were 97, 73, and 90%, respectively. In 22 patients with suspected very early and early postsurgical infections, the two imaging modalities were concordant in 17 cases [10 true positive (TP) and 7 true negative (TN)]. [18F]FDG PET/CT presented a higher sensitivity than 99mTc-HMPAO-WBC scan. 99mTc-HMPAO-WBC scan correctly classified as negative three false-positive (FP) PET/CT findings.Conclusion: Our findings supported the use of 99mTc-HMPAO-WBC SPECT/CT and [18F]FDG PET/CT in patients with suspicion infection after the Bentall procedure early in the course of the disease onset to confirm the diagnosis and provide a comprehensive assessment of disease burden through the proposed criteria.

Transcatheter aortic valve replacement associated infective endocarditis case series: broadening the criteria for diagnosis is the need of the hour

Background Transcatheter valve replacement (TAVR) is an important therapeutic intervention for patients with aortic valve stenosis. As TAVR has become available to a broader population, there has been an increase in the number of less common, yet potentially catastrophic, complications. TAVR related infective endocarditis (TAVR-IE) is a rare, but potentially fatal, complication. Case series We present here two patients that we encountered for TAVR associated infective endocarditis. Our first patient presented 5 weeks after his TAVR. His initial presentation was consistent with signs of sepsis. The patient then developed Mobitz type I block during hospital course. His TEE was negative for features of infective endocarditis. Due to high suspicion, patient was taken for surgical exploration and was found to have multiple foci of vegetation adhered to the stent frame. Our second patient presented with new onset pulmonary edema, worsening heart failure and systemic inflammatory response. A TEE was done for persistent MSSA bacteremia which showed stable prosthetic valve function with no signs of infective endocarditis. Patient was discharged with a prolonged course of intravenous antibiotics. Patient was re-admitted for worsening sepsis and blood cultures were positive for MSSA. Patient was taken for surgical exploration of his prosthetic aortic valve which showed purulent aortic root abscess. Conclusion Through these cases, we aim to raise awareness on TAVR-IE. Due to the atypical clinical presentation, the modified Duke criteria may not be sufficient to diagnose TAVR-IE. Transesophageal echocardiogram in TAVR-IE may be negative or indeterminate. Prosthetic valve shadow may obscure smaller vegetations and/or smaller abscesses. A negative transesophageal echocardiogram should not rule out TAVR-IE and further diagnostic imaging modalities should be considered. PET/CT after administration of 18F-FDG (fluorodeoxyglucose) is a useful diagnostic tool in the diagnosis of infective endocarditis where TEE has been negative or inconclusive. Multi-modal imaging, in addition to the modified Duke criteria, can facilitate early diagnosis and improved mortality outcomes.

691. Infective Endocarditis with an Indication for Cardiac Surgery in a Tertiary Care Educational Hospital: Does Cardiac Surgery Improve Outcomes?

Background In this retrospective cohort study, it was aimed to compare the clinical characteristics and outcomes of IE cases without and with an indication for cardiac surgery in terms of whether they have been operated or not, in a tertiary-care educational hospital. Methods Patients that were followed up for definite IE (diagnosed according to modified Duke criteria between March 2007 and November 2020) with an indication for cardiac surgery according to European Society of Cardiology Guidelines, comprised the study group. Subjects were evaluated in terms of whether these cases have been operated or not, demographic features, underlying diseases, risk factors, clinical and laboratory findings, therapy responses, complications, and mortality. The timing of surgery is defined as emergency; surgery performed within 24 hours, urgent; within a few days, elective; after at least one-two weeks of antibiotic therapy. Statistical analysis was performed via Chi square and Student T tests and a p value < 0.05 was considered significant. Results A total of 90 patients with an indication for surgery, 33.3% patients in underwent surgery, 66.6% patients in not underwent surgery group fulfilled the study criteria. The most frequently seen complaints in patients were fever (91.1%), cold-shiver (56.6%), weight-loss (27.7%), dyspnea (25.5%), and tachycardia (20%). Heart murmur was detected during cardiac auscultation of 44 patients. Mean blood leukocyte count, C-reactive protein and erythrocyte sedimentation rate were 12324 ± 6558/mm3 (1408-30330), 11.46 ± 8.38 mg/dl (0.18-34.6) and 61.43 ± 33.4 mm/h (2-130), respectively. There was no significant difference between two groups in terms of cardiac/non-cardiac risk factors, age, gender, etiologic agents, laboratory findings, septic embolisms and complaints (Table 1). In total IE with an indication for surgery mortality was 27.7%. Mortality rate was significantly less and heart murmur was significantly higher in cases who underwent surgery than those did not undergo surgery (p: 0.0447). Table 1. Comparison of basic characteristics of patients in the two operated / unoperated cohorts. Conclusion These data support the importance of the guidelines’ criteria for cardiac surgery in the management of IE. Assuming that only 1/3 of the surgery needing cases received surgery, more interventions are needed to decrease the barriers against surgery. Disclosures All Authors: No reported disclosures

683. Epidemiology and Microbiology of Infective Endocarditis: A Six Year Experience

Background The epidemiology and microbiology of infective endocarditis (IE) is not well studied in India. Studies from developed countries report a culture positivity of more than 90% in IE, while in India it has been lower (40–70%). Viridans Group Streptococci (VGS) are the commonest organism identified from previous Indian studies. The state of Kerala in India has better health indicators compared to the rest of India and it is likely that the epidemiology of IE in Kerala may be different. We therefore studied the epidemiology and microbiology of IE in patients admitted to a tertiary care hospital in Kerala over six years (2015 – 2020). Methods An electronic medical record search was conducted to identify patients who satisfied definite or possible IE criteria as per modified Duke criteria. Three sets of blood cultures were sent in BacT/Alert blood culture bottles for all suspected cases of IE. Blood culture was done using BacT-ALERT 3D automated microbial detection system (bioMérieux, France) and organisms were identified using VITEK-2 system. Transthoracic echocardiogram was done for all patients and a transoesophageal echocardiogram was done when indicated. Results 70 patients satisfied the inclusion criteria. Majority (70.4%) were male; mean age was 50.7±16.3 years. 71% patients had underlying valvular heart disease. Diabetes mellitus (53.5%) was the most common comorbidity followed by chronic kidney disease (18.3%). Mitral valve was most commonly affected (53.5%) followed by the aortic valve (19.7%) and both valves were involved in 5.7%. Right sided valves were affected in 8.5%. Prosthetic valve endocarditis accounted for 10% of cases. No echocardiographic evidence of endocarditis was seen in 11.3%. Blood culture was positivity was 64.8%. Staphylococcus aureus (20%) was the most common organism isolated, followed by VGS (17.1%). 50% of the Staphylococcus aureus isolated were methicillin resistant. Among 57 patients in whom an outcome was recorded, mortality was 12.2%. Microbiology profile of infective endocarditis Conclusion Staphylococcus aureus has emerged as the most common etiological agent of IE in our study, in contrast to previous studies from India where VGS was predominant. The high prevalence of MRSA is of concern. Disclosures All Authors: No reported disclosures

Abstract 1122‐000111: Embolic Stroke of Undermined Significance with Unusual Degree of CSF Neutrophilic Pleocytosis

Introduction : A 50 year old African American female with a history of hyperlipidemia, hypertension, diabetes mellitus, and peripheral artery disease with right lower extremity bypass earlier in 2021 presented with altered mental status (AMS) and right‐sided facial droop. She presented to an outside hospital where her temperature was 102.1°F and blood pressure was 185/84. The National Institute of Health Stroke Scale (NIHSS) was 16. Notable labs included white blood cell (WBC) count 10.3, sodium 133, lactate 2.7. Urine drug screen notable for THC. Urinalysis, CXR, COVID screen were negative. CT of the head did not show acute findings, CT angiogram did not show any stenosis or large vessel occlusions and CT perfusion revealed perfusion deficits in the left hemisphere. Given her elevated temperature and lactate, a lumbar puncture (LP) was performed. Cerebrospinal fluid (CSF) analysis revealed WBC count 58 (95% neutrophilic predominance), RBC count 128, glucose 324 (serum glucose 576), protein 77 and lactate dehydrogenase (LDH) 23. Concerns for meningitis lead to her being started on broad spectrum antibiotics (ampicillin, ceftriaxone, acyclovir, and vancomycin). She was then transferred to our comprehensive stroke center for further management. Methods : Initially she remained febrile and somnolent, but after 36 hours of antibiotics, her mentation improved. Antibiotics and antivirals were slowly tapered after the CSF meningitis panel, gram stain, cultures, and viral PCRs came back negative. MRI of brain showed acute left posterior cerebral artery (PCA) ischemic stroke with punctate infarcts of right lentiform nucleus and periventricular area. Transthoracic echocardiogram (TTE) showed the left ventricle with severe hypertrophy and ejection fraction (EF) 65–70%. There was concern for endocarditis with systemic infection, however transesophageal echocardiogram (TEE) was negative for infectious vegetations and bubble study was negative. Blood cultures showed no growth after four days. Syphilis screen, ANA, HIV were also negative. Lipids were elevated with total cholesterol 214 and LDL 138. Hemoglobin A1c was also elevated at 13. Results : After being stable for several days, the patient’s NIHSS reduced to three, two points for right homonymous hemianopia and one point for minor facial paralysis. An implantable loop recorder was placed to monitor for any arrhythmias that may have led to her stroke and the patient was discharged home on aspirin and atorvastatin. Conclusions : With the initial presentation of fever and AMS in this patient, there was high suspicion of infective endocarditis. She also suffered an ischemic stroke which was determined to be embolic from an undetermined source. The patient did not meet modified Duke Criteria for “possible infective endocarditis” which is considered when the patient has one major and one minor criteria or three minor criteria. Two minor criteria were met including a temperature > 38oC on admission and vascular embolic phenomena (stroke). Interestingly, blood and CSF cultures never grew an organism although the CSF WBC count was 58. While CSF lymphocytosis has been associated with TIA‐like presentations and other viral or fungal etiologies associated with ischemic stroke, this is perhaps the first case of a neutrophilic‐predominant CSF pleocytosis in setting of ischemic stroke without a clear source.

Evolving trends in infective endocarditis over three decades in a developing country

Introduction Infective endocarditis (IE) is a rare serious disease for which diagnosis and treatment and prophylaxis continue to develop. Purpose The aim of our work were to analyze evolution in its epidemiologic, clinical, and microbiologic characteristics, as well as the outcomes. Methods This study compare data from a retrospective study conducted by Bennis and Al based on 157 cases of infectious endocarditis admitted in tertiary care Hospital between January 1983 and December 1994, theses cases are referred as Group A; and 103 cases of infective endocarditis according to Duke criteria admitted to the same center three decades afterwards from december 2013 to January 2020, which are referred as Group B. Results The mean age of the patients has became older over decades, with a mean of 27.5 years (11–65 years) in the group A versus 39.2 years [13–84] in the group B, with preservation of the male predominance (62.8% in group A vs 62.1% in group B). Infectious endocarditis secondary to rheumatic valvular heart disease has significantly decreased from 63.% of patients in group A to 27.5% in group B. Mitral or mitro-aortic valve involvement stayed predominant in both groups with a increase of mechanical prosthetic valve involvement with 9.7% in group B. A portal of entry of the infection was identified in 63% of patients in group A versus 41% in group B, we noted a significant decrease of dental-related cases from 64% in group A to 29% in group B, and a predominance of invasive procedure/devices cases in group B with 36% of identified cases. In group A Blood cultures were positive in 42% of cases with a predominance of Staphylocci (30%) and coagulase-negative Staphylococci (25.7% of cases) whilst in group B blood cultures were positive in 30% of cases with a predominance of Staphylococci (36.6%) and Streptococci (20% of cases). Echocardiography as a useful diagnostic tool demonstrated specific lesions of infectious endocarditis (abcess or vegetations) in 73.2% of cases in group A and 82% in group B. The clinical course in group A was complicated by congetive heart failure CHF (47.8%) or neurological lesions (11.5%) while in group B CHF was noted in 35% of cases and 8% of neurological lesions and The global mortality went from 28.7% in group A to 15% in group B related mostly to cardiogenic shock. Conclusion Our work demonstrated changes in the epidemiologic characteristics of IE that parallel changes in demographic and risk factors. The progress of diagnosis and treatement options in developing countries explains the better prognosis for this condition today. FUNDunding Acknowledgement Type of funding sources: None.

SHARPEN score: an independent predictor of survival after infective endocarditis discharge

Background Infective endocarditis (IE) presents high mortality even in patients that were adequately treated. Proper identification of these patients is imperative for better care delivery. SHARPEN score (Systolic BP, Heart failure, Age, Renal function, Pneumonia, Elevated peak CRP, and Non-intravenous drug abusers) was validated to predict in-hospital mortality due to IE; its performance in predicting survival after hospital discharge, however, has not yet been evaluated. Purpose To assess the SHARPEN score in predicting survival after hospital discharge due to IE. Methods Retrospective cohort study including all patients ≥18 years discharged after definitive IE (modified Duke criteria) admission at a public tertiary teaching hospital in southern Brazil, between 2000–16. Only the first hospitalization for IE was considered in those patients with >1 admission for that reason in the studied period. The SHARPEN score was calculated at admission, and each patient was classified as low-moderate (2–10 points) or high (11–20 points) risk. Follow-up was carried out through the review of medical records, and the assessed outcome was death by any cause. Survival analysis was performed using the Kaplan-Meier curves, which were compared using the Log-rank test. Results A total of 135 patients (mean age: 53±17 years, 97 [72%] male) were discharged after IE episode. Staphylococcus aureus was the main etiologic agent (29 [21.5%]), and cardiac surgery was performed in 54 (40%) patients. The median SHARPEN score was 9 (IQR: 7–11 points), being classified as low-moderate risk (96 [71%]) and high risk (39 [29%]) patients, respectively. Median post-discharge follow-up was 3.4 (IQR: 0.19–9) years (682 patient-years), with 37 deaths during the period. Mean post-discharge survival was 12.4 years (95% CI: 10.7–14), significantly higher in patients classified as low-moderate risk (13.7 years) in comparison to high risk (8.4 years) (Log-rank P=0.006; Figure). Conclusion Patients classified as high-risk by SHARPEN score during IE admission present significantly higher mortality after discharge, despite being effectively treated for the IE episode. SHARPEN score could also be used to assess morbimortality after discharge, helping to implement special care programs for high-risk patients. FUNDunding Acknowledgement Type of funding sources: None.