Diagnosis Of Native Valve Endocarditis Research Articles

Infective Endocarditis after Transcatheter Aortic Valve Replacement: Challenges in the Diagnosis and Management

Although initially conceived for high-risk patients who are ineligible for surgical aortic valve replacement (SAVR), transcatheter aortic valve replacement (TAVR) is now recommended in a wider spectrum of indications, including among young patients. However, similar to SAVR, TAVR is also associated with a risk of infectious complications, namely, prosthetic valve endocarditis (PVE). As the number of performed TAVR procedures increases, and despite the low incidence of PVE post-TAVR, clinicians should be familiar with its associated risk factors and clinical presentation. Whereas the diagnosis of native valve endocarditis can be achieved straightforwardly by applying the modified Duke criteria, the diagnosis of PVE is more challenging given its atypical symptoms, the lower sensitivity of the criteria involved, and the low diagnostic yield of conventional echocardiography. Delay in proper management can be associated with increased morbidity and mortality. Therefore, clinicians should have a high index of suspicion and initiate proper work-up according to the severity of the illness, the underlying host, and the local epidemiology of the causative organisms. The most common causative pathogens are Gram-positive bacteria such as Staphylococcus aureus, coagulase-negative staphylococci, Enterococcus spp., and Streptococcus spp. (particularly the viridans group), while less-likely causative pathogens include Gram-negative and fungal pathogens. The high prevalence of antimicrobial resistance complicates the choice of therapy. There remain controversies regarding the optimal management strategies including indications for surgical interventions. Surgical assessment is recommended early in the course of illness and surgical intervention should be considered in selected patients. As in other PVE, the duration of therapy depends on the isolated pathogen, the host, and the clinical response. Since TAVR is a relatively new procedure, the outcome of TAVR-PVE is yet to be fully understood.

Abstract 13294: Role of Retrospective Cardiac Computed Tomography Angiography in the Detection of Prosthetic Valve Endocarditis

Case presentation A 47-year-old man was readmitted for evaluation of recurrent fevers, night sweats, and weight loss over a 3 month period. He had a history of bioprosthetic aortic and mitral valve replacements for rheumatic valve disease and heart failure with reduced ejection fraction due to non-ischemic cardiomyopathy. Physical examination was remarkable for a[LMD1] grade II/VI systolic murmur. Laboratory notable for neutrophilic leukocytosis elevated C-reactive protein and erythrocyte sedimentation rate. Blood cultures demonstrated Staphylococcus epidermidis . On transthoracic echocardiogram (TTE) performed in the current admission and transesophageal echocardiogram (TEE) done 2 months prior the prosthetic valves were not clearly visualized, but there was no regurgitation, stenosis or vegetation noted. Due to a high index of suspicion for prosthetic valve endocarditis (PVE), a retrospectively gated cardiac computed tomography angiography (CCTA) of the entire cardiac cycle was performed. It revealed a 13 mm mobile vegetation attached to the ventricular side of the left coronary cusp (Figure 1). Subsequently, the patient underwent a redo aortic valve replacement. Blood cultures cleared and the patient was discharged on hospital day 16 to complete 6 weeks of Cefazolin and Rifampin. Discussion: The modified Duke criteria play an important role in the diagnosis of native valve infective endocarditis (IE) (~ 80% sensitive), but it carries a lower diagnostic yield in the detection of PVE. While TEE carries high accuracy in the diagnosis of native valve endocarditis, approximately 30% of patients with PVE and/or intra-cardiac devices have inconclusive or normal echocardiographic findings. Inability to recognize IE in a timely fashion (<4 days) leads to greater embolic events. We showed how CCTA can be used to expedite the diagnosis of PVE.

18F]FDG-PET CT for the evaluation of native valve endocarditis

BackgroundWe examined the use of [18F]FDG-PET/CT for the diagnosis of native valve endocarditis (NVE). MethodsPET/CT images in patients with suspected NVE were retrospectively reviewed independently by two experienced physicians blinded to all clinical information. The gold standard consisted of surgical findings, when available, or the modified Duke criteria. ResultsFifty four subjects were included, 31 (57%) with a diagnosis of NVE. [18F]FDG-PET/CT correctly identified 21/31 (67.7%) subjects, yielding a sensitivity and specificity of 68% (95% CI 49-83%) and 100% (95% CI 85-100%), respectively. The sensitivity and specificity of the modified Duke criteria were 48% and 74%, respectively. Positive and negative predictive values of PET were 100% (95% CI 84-100%) and 70% (95% CI 51-84%), respectively. Modifying the Duke criteria to include [18F]FDG-PET positivity as a major criterion increased sensitivity to 77% without affecting specificity and led to the correct reclassification of 8/18 (44.4%) subjects from Possible IE to Definite IE. ConclusionThe addition of a positive [18F]FDG-PET/CT as a major criterion in the modified Duke Criteria improved performance of the criteria for the diagnosis of NVE, particularly in those subjects with Possible IE.

Diagnostic Performance of 18F-FDG PET/CT in Native Valve Endocarditis: Systematic Review and Bivariate Meta-Analysis.

Background: Infectious endocarditis is a life-threatening disease, requiring prompt and accurate diagnosis. The aim of this article is to perform a systematic review and meta-analysis of the literature to estimate the performance of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for the diagnosis of native valve endocarditis (NVE). Methods: Selected articles evaluating the diagnostic accuracy of 18F-FDG PET/CT in patients with suspected NVE, resulting from a comprehensive literature search through the PubMed/MEDLINE and Cochrane library databases until April 2020, were included for the systematic review and meta-analysis. Results: Seven studies (351 episodes of suspected NVE) were included. 18F-FDG PET/CT yielded a pooled sensitivity of 36.3% and a pooled specificity of 99.1% for the diagnosis of NVE. The pooled positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 8.3, 0.6, and 15.3, respectively. The sensitivity increased using contemporary PET/CT device with state-of-the-art patient preparation as well as innovative image acquisitions or adding the results of 18F-FDG PET/CT in a multimodality strategy. Conclusions: In our systematic review and meta-analysis, 18F-FDG PET/CT yielded a poor pooled sensitivity with an otherwise excellent pooled specificity for the diagnosis of NVE; however, several factors may increase the sensitivity without affecting the specificity and these factors should be better evaluated in future studies.

Meta-analysis of 18F-FDG PET/CT in the diagnosis of infective endocarditis

BackgroundThe current diagnosis of infective endocarditis (IE) is based on the modified Duke criteria, which has approximately 80% sensitivity for the diagnosis of native valve endocarditis (NVE), with lower sensitivity for the diagnosis of prosthetic valve endocarditis (PVE) and culture-negative endocarditis. There is preliminary evidence that 18F-FDG PET/CT is an adjunctive diagnostic test with high accuracy reported in small studies to date. We therefore performed a meta-analysis of studies evaluating the use of PET/CT in the diagnosis of IE to establish a more precise estimate of accuracy. MethodsPubMed, Embase, Cochrane library, CINAHL, Web of Knowledge, and www.clinicaltrials.gov were searched from January 1990 to April 2017 for studies evaluating the accuracy of PET/CT for the evaluation of possible IE. ResultsWe identified 13 studies involving 537 patients that were included in the meta-analysis. The pooled sensitivity of PET/CT for diagnosis of IE was 76.8% (95% CI 71.8–81.4%; Q = 39.9, P < 0.01; I2 = 69.9%) and the pooled specificity was 77.9% (95% CI 71.9–83.2%; Q = 44.42, P < 0.01; I2 = 73.0%). Diagnostic accuracy was improved for PVE with sensitivity of 80.5% (95% CI 74.1–86.0%; Q = 25.5, P < 0.01; I2 = 72.5%) and specificity of 73.1% (95% CI 63.8–81.2%; Q = 32.1, P < 0.01; I2 = 78.2%). Additional extracardiac foci of infection were found on 17% of patients on whole body PET/CT. ConclusionPET/CT is a useful adjunctive diagnostic tool in the evaluation of diagnostically challenging cases of IE, particularly in prosthetic valve endocarditis. It also has the potential to detect clinically relevant extracardiac foci of infection, malignancy, and other sources of inflammation leading to more appropriate treatment regimens and surgical intervention.

The Role of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Diagnosis of Left-sided Endocarditis: Native vs Prosthetic Valves Endocarditis.

18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) has emerged as a useful diagnostic tool for suspected infective endocarditis (IE) in patients with prosthetic valves or implantable devices. However, there is limited evidence regarding use of 18F-FDG-PET/CT for the diagnosis of native valve endocarditis (NVE). Between 2014 and 2017, 303 episodes of left-sided suspected IE (188 prosthetic valves/ascending aortic prosthesis and 115 native valves) were studied. 18F-FDG-PET/CT accuracy was determined in the subgroups of patients with NVE and prosthetic valve endocarditis (PVE)/ascending aortic prosthesis infection (AAPI). Associations between inflammatory infiltrate patterns and 18F-FDG-PET/CT uptake were investigated in an exploratory ad hoc histological analysis. Among 188 patients with PVE/AAPI, the sensitivity, specificity, and positive and negative predictive values of 18F-FDG-PET/CT focal uptake were 93%, 90%, 89%, and 94%, respectively, while among 115 patients with NVE, the corresponding values were 22%, 100%, 100%, and 66%. The inclusion of abnormal 18F-FDG cardiac uptake as a major criterion at admission enabled a recategorization of 76% (47/62) of PVE/AAPI cases initially classified as "possible" to "definite" IE. In the histopathological analysis, a predominance of polymorphonuclear cell inflammatory infiltrate and a reduced extent of fibrosis were observed in the PVE group only. Use of 18F-FDG-PET/CT at the initial presentation of patients with suspected PVE increases the diagnostic capability of the modified Duke criteria. In patients who present with suspected NVE, the use of 18F-FDG-PET/CT is less accurate and could only be considered a complementary diagnostic tool for a specific population of patients with NVE.

Native Aortic Valve Endocarditis—A Case Report

Introduction: To report a case of isolated “endocarditic” aortic regurgitation in a 17-year old female with infective vegetations on aortic valve. Case Report: A 17-year old female was admitted with features of heart failure and a febrile illness. Blood cultures were negative and ECG revealed normal. Echocardiography revealed a “kissing-type” of vegetation on the bicuspid aortic valve with severe aortic regurgitation and a dilated left ventricle with moderate dysfunction. Conclusion: The management of aortic insufficiency occurring in infective endocarditis may differ and the presence of intractable pulmonary edema or shock is a clear indication for prompt valve replacement. The traditional diagnostic criteria are insufficient to diagnose infective endocarditis and the modified Duke criteria provide high sensitivity and specificity over 80% for the diagnosis of native valve endocarditis with positive blood cultures.