Preoperative Evaluation in Aortic Endocarditis: Findings on Cardiac CT

Cardiac computed tomography in infective endocarditis: "bridging the detection gap"

Infective Endocarditis (IE) remains a significant health challenge. Despite an increasing awareness, mortality is high and has remained largely unchanged over recent decades. Early diagnosis of IE is imperative and to assist clinicians several diagnostic criteria have been proposed. The best known are the Duke criteria. Originally published in 1994, these criteria have undergone significant modifications. This manuscript provides a timeline of the successive changes that have been made over the last 30 years. Changes which to a large degree have reflected both the evolving epidemiology of IE and the proliferation and increasing availability of advanced multi-modality imaging. Importantly, many of these changes now form part of societal guidelines for the diagnosis of IE. To provide validation for the incorporation of cardiac computed tomography (CT) in current guidelines, the manuscript demonstrates a spectrum of pictorial case studies that re-enforce the utility and growing importance of early cardiac CT in the diagnosis and treatment of suspected IE.

Imaging in Infective Endocarditis-Current Opinions and Trends in Cardiac Computed Tomography

Infective endocarditis is a rare disease with an increasing incidence and an unaltered high mortality rate, despite medical development. Imaging plays an integrative part in the diagnosis of infective endocarditis, with echocardiography as the initial diagnostic test. Research data in the utility of cardiac computed tomography (CCT) in the diagnostic algorithm of IE are rising, which indicates its importance in detection of IE-related lesion along with the exclusion of coronary artery disease. The latest 2023 European Society of Cardiology Guidelines in the management of IE classified CCT as class of recommendation I and level of evidence B in detection of both valvular and paravalvular lesions in native and prosthetic valve endocarditis. This review article provides a comprehensive and contemporary review of the role of CCT in the diagnosis of IE, the optimization of acquisition protocols, the morphology characteristics of IE-related lesions, the published data of the diagnostic performance of CCT in comparison to echocardiography as the state-of-art method, as well as the limitations and future possibilities.

Contemporary surgical management of infective endocarditis of the aortic root

Infective endocarditis involving the aortic root is associated with a high degree of morbidity and mortality. Native aortic root infections can develop from aggressive organisms or from delays in diagnosis or definitive care, whereas prosthetic valve infections commonly result in extensive destruction of the aortic root and neighboring structures. Early detection, tailored antibiotic therapy, thoughtful pre-operative planning, and multidisciplinary heart team management are the keys to optimizing patient outcomes. Aggressive and complete surgical debridement are mandatory prior to aortic root reconstruction. Surgical experience and patient-centered decision making are critical in selecting the optimal reconstructive strategy for the aortic root and adjacent structures.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01604-6.

Computed Tomography in Infectious Endocarditis

Imaging is one of the cornerstones in diagnosis and management of infective endocarditis, underlined by recent guidelines. Echocardiography is the first-line imaging technique, however, computed tomography (CT) has a class I recommendation in native and prosthetic valve endocarditis to detect valvular lesions in case of possible endocarditis and to detect paravalvular and periprosthetic complications in case of inconclusive echocardiography. Echocardiography has a higher diagnostic accuracy than CT in detecting valvular lesions, but not for diagnosing paravalvular lesions where CT is superior. Additionally, CT is useful and recommended by guidelines to detect extracardiac manifestations of endocarditis and in planning surgical treatment including assessment of the coronary arteries. The advent of photon-counting CT and its improved spatial resolution and spectral imaging is expected to expand the role of CT in the diagnosis of infective endocarditis. In this review, we provide an overview of the current role of CT in infective endocarditis focusing on image acquisition, image reconstruction, interpretation, and diagnostic accuracy.

Multimodality Imaging Diagnosis in Infective Endocarditis

Imaging is an important tool in the diagnosis and management of infective endocarditis (IE). Echocardiography is an essential examination, especially in native valve endocarditis (NVE), but its diagnostic accuracy is reduced in prosthetic valve endocarditis (PVE). The diagnostic ability is superior for transoesophageal echocardiography (TEE), but a negative test cannot exclude PVE. Both transthoracic echocardiography (TTE) and TEE can provide normal or inconclusive findings in up to 30% of cases, especially in patients with prosthetic devices. New advanced non-invasive imaging tests are increasingly used in the diagnosis of IE. Nuclear medicine imaging techniques have demonstrated their superiority over TEE for the diagnosis of PVE and cardiac implantable electronic device infective endocarditis (CIED-IE). Cardiac computed tomography angiography imaging is useful in PVE cases with inconclusive TTE and TEE investigations and for the evaluation of paravalvular complications. In the present review, imaging tools are described with their values and limitations for improving diagnosis in NVE, PVE and CIED-IE. Current knowledge about multimodality imaging approaches in IE and imaging methods to assess the local and distant complications of IE is also reviewed. Furthermore, a potential diagnostic work-up for different clinical scenarios is described. However, further studies are essential for refining diagnostic and management approaches in infective endocarditis, addressing limitations and optimizing advanced imaging techniques across different clinical scenarios.

Novel putative biomarkers for infective endocarditis by serum proteomic analysis: a comprehensive review of literature

Infective endocarditis (IE) is a challenging condition with high mortality. Prompt detection of IE has become essential for early and immediate management. The authors aimed to comprehensively review the existing literature on novel putative biomarkers for IE through serum proteomic analysis. The literature reveals high levels of N-terminal-pro-B-type natriuretic peptide (NT-proBNP) levels in IE with staphylococcal etiology, valvular lesions, and when combined with cardiac troponin I (cTnI), had a more significant value for risk stratification. A higher pro-ADM level, copeptin, NT-proBNP, and the monocyte-to-high-density lipoprotein cholesterol ratio (MHR) all impacted mortality during the hospital stay. The biomarker matrix metalloproteinase-9 was utilized to predict new-onset embolic events in patients, thus serving as a predictive marker. Procalcitonin was an important diagnostic marker in IE complicated with severe infection. Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interferon-γ, cTnI, and NT-proBNP were also discovered to be useful as prognostic indicators. Early diagnosis and appropriate treatment are possible using antiphospholipid antibodies as a diagnostic test for definite IE. It is also concluded that antineutrophilic cytoplasmic antibody positive individuals with IE had a lengthier hospital stay. These noninvasive biomarkers can identify patients at risk and provide appropriate and early clinical management. NT-proBNP, Cystatin C, troponins, IL-6, IL-8, S100A11, and AQP9 are examples of possible markers that appear promising for further research. In conclusion, large-scale validation studies should study these biomarkers further to establish their use in clinical settings.

Patients with Artificial Heart Valves

BACKGROUND

In Germany, a total of 38 547 heart valve procedures were performed in 2022. With a growing number of patients undergoing the surgical and interventional implantation of heart valves, the incidence of prosthetic endocarditis is also rising.

METHODS

We summarize the current state of the prophylaxis, diagnosis, and treatment of prosthetic endocarditis in a selective review of the literature.

RESULTS

Prosthetic endocarditis accounts for 10-30% of all cases of endocarditis. As its echocardiographic and microbiologic findings are often less specific than those of native endocarditis, its diagnosis now increasingly relies on alternative imaging modalities such as F-18-FDG PET-CT. Anti-infective and surgical treatment are made more difficult by biofilm formation on the prosthetic valve and the frequent formation of perivalvular abscesses.

CONCLUSION

Increased awareness of this clinical entity in the outpatient setting will promote the earlier initiation of appropriate diagnostic studies. Proper diagnostic evaluation is an essential prerequisite for the early detection and timely treatment of prosthetic endocarditis, with the goal of preventing progressive destruction and thus improving the outcome. Preventive and educative measures should be intensified, and certified, multidisciplinary endocarditis teams should be established. Antibiotic prophylaxis is now given much more restrictively than in earlier years; the risk of infection must be weighed against the potential development of both individual and collective resistance to antibiotic drugs.

The Role of Echocardiography and Cardiac Computed Tomography in Diagnosis of Infective Endocarditis

BACKGROUND

Infective endocarditis (IE) is a rare disease with a high mortality rate and rising incidence, requiring timely and precise diagnosis in order to choose appropriate therapy. Imaging of morphologic lesions is an integrative part of diagnosis. Artifacts and the patient's habitus make echocardiography difficult to visualize advanced-form IE. Cardiac computed tomography (CCT) constantly shows an additive diagnostic value due to high resolution of cardiac anatomy. Conjecturally, joint application of both diagnostic tests improves overall sensitivity and specificity in diagnosing IE.

METHODS

Patients with definite IE underwent transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and CCT. We analyzed valvular and paravalvular IE lesions in all three imaging methods and compared them to surgical or autopsy findings. We calculated sensitivity, specificity, diagnostic accuracy, and positive and negative predictive value of both imaging tests individually and jointly used.

RESULTS

We examined 78 patients, male to female ratio 2:1, mean age 52.29 ± 16.62. We analyzed 85 valves, 70 native valves, 13 prosthetic valves, and 2 corrected valves due to Ozaki procedure, along with a central shunt and 4 pacemaker leads. As a single test, the sensitivity and specificity of CCT, TTE, and TEE for valvular lesions were 91.6/20%, 65.5/57.9%, and 60/84%, and paravalvular lesions were 100/0%, 46/10.5%, and 14.7/100%. When combined together, sensitivity and specificity for valvular lesions rose to 96.6/0% and paravalvular lesions to 100/0%. We also analyzed the diagnostic performance for each test in single and mutual application, per specific IE lesion.

CONCLUSION

In the individual application, CCT in comparison to TTE and TEE shows better diagnostic performance in detection of valvular and paravalvular lesions. In joint application, there is a statistically significant difference in performance compared to their single use, especially in prosthetic valves and invasive forms of IE native valves.

Usefulness of cardiac computed tomography in prosthetic heart valve dysfunction

BACKGROUND

Prosthetic heart valve (PHV) dysfunction is a serious complication. Echocardiography remains the first-line imaging investigation to assess PHV dysfunction. However, the role of Computed Tomography (CT) scanning in this type of case has not been thoroughly studied yet. The objective of our study was to determine if cardiac Computed Tomography (CT) had a potentially complementary role to play alongside echocardiography in diagnosing the mechanism of prosthetic valve dysfunction.

METHODS AND RESULTS

This prospective cohort study was conducted on 54 patients with suspected PHV dysfunction. All patients underwent routine diagnosis work-up (transthoracic and transesophageal echocardiography) and additional cardiac CT. Cardiac CT showed findings that were not detected by echocardiography in seven patients (12%) namely aortic pannus (5) and pseudoaneurysm (2). An underlying thrombus was detected by echocardiography and missed by cardiac CT in 15 patients (27%). However, in these thrombotic cases, cardiac CT contributed to the functional evaluation of leaflets.

CONCLUSION

This study demonstrates that an integrated approach including transthoracic, transesophageal echocardiography and computed tomography is useful in patients with suspected PHV dysfunction. While computed tomography is more accurate in the diagnosis of pannus formation and periannular complications, echocardiography is superior at detecting thrombus.

Current Views on Infective Endocarditis: Changing Epidemiology, Improving Diagnostic Tools and Centering the Patient for Up-to-Date Management

Infective endocarditis (IE) is a rare but potentially life-threatening disease, sometimes with longstanding sequels among surviving patients. The population at high risk of IE is represented by patients with underlying structural heart disease and/or intravascular prosthetic material. Taking into account the increasing number of intravascular and intracardiac procedures associated with device implantation, the number of patients at risk is growing too. If bacteremia develops, infected vegetation on the native/prosthetic valve or any intracardiac/intravascular device may occur as the final result of invading microorganisms/host immune system interaction. In the case of IE suspicion, all efforts must be focused on the diagnosis as IE can spread to almost any organ in the body. Unfortunately, the diagnosis of IE might be difficult and require a combination of clinical examination, microbiological assessment and echocardiographic evaluation. There is a need of novel microbiological and imaging techniques, especially in cases of blood culture-negative. In the last few years, the management of IE has changed. A multidisciplinary care team, including experts in infectious diseases, cardiology and cardiac surgery, namely, the Endocarditis Team, is highly recommended by the current guidelines.

Expanding utility of cardiac computed tomography in infective endocarditis: A contemporary review

There is increasing evidence on the utility of cardiac computed tomography (CCT) in infective endocarditis (IE) to investigate the valvular pathology, the extra-cardiac manifestations of IE and pre-operative planning. CCT can assist in the diagnosis of perivalvular complications, such as pseudoaneurysms and abscesses, and can help identify embolic events to the lungs or systemic vasculature. CCT has also been shown to be beneficial in the pre-operative planning of patients by delineating the coronary artery anatomy and the major cardiovascular structures in relation to the sternum. Finally, hybrid nuclear/computed tomography techniques have been shown to increase the diagnostic accuracy in prosthetic valve endocarditis. This manuscript aims to provide a contemporary update of the existing evidence base for the use of CCT in 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.

Perivalvular Extension of Infective Endocarditis after Transcatheter Aortic Valve Replacement

BACKGROUND

Infective endocarditis (IE) following transcatheter aortic valve replacement (TAVR) has been associated with a dismal prognosis. However, scarce data exist on IE perivalvular extension (PEE) in such patients.

METHODS

This multicenter study included a total of 579 patients who had the diagnosis of definite IE at a median of 171 (53-421) days following TAVR. PEE was defined as the presence of an intracardiac abscess, pseudoaneurysm or fistula confirmed by transthoracic/transophageal echocardiography, computed tomography or peri-operative findings.

RESULTS

A total of 105 patients (18.1%) were diagnosed with PEE (perivalvular abscess, pseudoaneurysm, fistula, or a combination in 87, 7, 7, and 4 patients, respectively). A history of chronic kidney disease (ORadj: 2.08; 95% CI: [1.27-3.41], p=0.003) and IE secondary to coagulase-negative staphylococci (ORadj: 2.71; 95% CI: [1.57-4.69], p<0.001) was associated with an increased risk of PEE. Surgery was performed at index IE episode in 34 patients (32.4%) with PEE (vs. 15.2% in patients without PEE, p<0.001). In-hospital and 2-year mortality rates among PEE-IE patients were 36.5% and 69.4%, respectively. Factors independently associated with an increased mortality risk were the occurrence of other complications (stroke post-TAVR, acute renal failure, septic shock) and the lack of surgery at index IE hospitalization (padj<0.05 for all).

CONCLUSION

PEE occurred in about one fifth of IE post-TAVR patients, with the presence of coagulase-negative staphylococci and chronic kidney disease determining an increased risk. Patients with PEE-IE exhibited very high early and late mortality rates, and surgery during IE hospitalization seemed to be associated with better outcomes.

Should We Quantify Valvular Calcifications on Cardiac CT in Patients with Infective Endocarditis?

BACKGROUND

Evaluate the impact of valvular calcifications measured on cardiac computed tomography (CCT) in patients with infective endocarditis (IE).

METHODS

Seventy patients with native IE (36 aortic IE, 31 mitral IE, 3 bivalvular IE) were included and explored with CCT between January 2016 and April 2018. Mitral and aortic valvular calcium score (VCS) were measured on unenhanced calcium scoring images, and correlated with clinical, surgical data, and 1-year death rate.

RESULTS

VCS of patients with mitral IE and no peripheral embolism was higher than those with peripheral embolism (868 (25-1725) vs. 6 (0-95), p < 0.05). Patients with high calcified mitral IE (mitral VCS > 100; n = 15) had a lower rate of surgery (40.0% vs.78.9%; p = 0.03) and a higher 1-year-death risk (53.3% vs. 10.5%, p = 0.04; OR = 8.5 (2.75-16.40) than patients with low mitral VCS (n = 19). Patients with aortic IE and high aortic calcifications (aortic VCS > 100; n = 18) present more frequently atypical bacteria on blood cultures (33.3% vs. 4.8%; p = 0.03) than patients with low aortic VCS (n = 21).

CONCLUSION

The amount of valvular calcifications on CT was associated with embolism risk, rate of surgery and 1-year risk of death in patients with mitral IE, and germ's type in aortic IE raising the question of their systematic quantification in native IE.

Imaging Spectrum of Valvular and Paravalvular Complications of Prosthetic Heart Valve at CT Angiography

Prosthetic heart valve (PHV) dysfunction is an uncommon but potentially life-threatening condition. In routine practice, transthoracic echocardiography and cinefluoroscopy comprise first-line imaging for the diagnostic evaluation of PHV dysfunction. In cases in which the findings of echocardiography and cinefluoroscopy remain inconclusive or are contradictory, CT angiography can resolve these conflicts. CT angiography also provides incremental diagnostic information about patients with suspected PHV obstruction and endocarditis, in which case it can demonstrate the anatomic substrate and extent of involvement. Additionally, information regarding the coronary arteries, cardiac dimensions, and retrosternal space may be obtained in cases in which repeat surgery is planned. This imaging essay describes the imaging spectrum of valvular and paravalvular complications of PHV at CT angiography and how the knowledge regarding the spectrum of complications can be incorporated into multimodality imaging for guiding clinical management. Keywords: Prosthetic Heart Valve Dysfunction, Prosthetic Heart Valve Thrombosis, Pannus, Paravalvular Leak, CT Angiography, Cardiac, Valves Supplemental material is available for this article. © RSNA, 2021.

Imaging of Cardiac Infections: A Comprehensive Review and Investigation Flowchart for Diagnostic Workup

Infections of the cardiovascular system may present with nonspecific symptoms, and it is common for patients to undergo multiple investigations to arrive at the diagnosis. Echocardiography is central to the diagnosis of endocarditis and pericarditis. However, cardiac computed tomography (CT) and magnetic resonance imaging also play an additive role in these diagnoses; in fact, magnetic resonance imaging is central to the diagnosis of myocarditis. Functional imaging (fluorine-18 fluorodeoxyglucose-positron emission tomography/CT and radiolabeled white blood cell single-photon emission computed tomography/CT) is useful in the diagnosis in prosthesis-related and disseminated infection. This pictorial review will detail the most commonly encountered cardiovascular bacterial and viral infections, including coronavirus disease-2019, in clinical practice and provide an evidence basis for the selection of each imaging modality in the investigation of native tissues and common prostheses.

ACR Appropriateness Criteria® Infective Endocarditis

Infective endocarditis can involve a normal, abnormal, or prosthetic cardiac valve. The diagnosis is typically made clinically with persistently positive blood cultures, characteristic signs and symptoms, and echocardiographic evidence of valvular vegetations or valvular complications such as abscess, dehiscence, or new regurgitation. Imaging plays an important role in the initial diagnosis of infective endocarditis, identifying complications, prognostication, and informing the next steps in therapy. This document outlines the initial imaging appropriateness of a patient with suspected infective endocarditis and for additional imaging in a patient with known or suspected infective endocarditis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Impact of Cardiac Computed Tomographic Angiography on Diagnostic and Therapeutic Decisions in Patients with Suspected Prosthetic Heart Valve Dysfunction

Introduction

Computed Tomography (CT) scan is a helpful tool to assess the coronary arteries and the great vessels. However, its routine use in the assessment of patients with suspected prosthetic valve dysfunction (PVD) has not been studied thoroughly.

Objective

To determine the impact of routine cardiac computed tomography angiography (CCTA) on diagnostic and therapeutic decisions in patients with suspected PVD.

Methods and results

This was a prospective cohort study that was conducted on 50 consecutive patients with suspected PVD who underwent both 64-slice ECG-gated CT and transesophageal echocardiography (TEE). The gold standard was the intraoperative findings. Surgery was performed in forty-six patients. ECG-gated CT showed findings that were not detected by TEE in sixteen patients (32%) namely aortic root abscess, aortic pseudoaneurysm, paravalvular leakage (PVL), sclero-calcific disruption of sutures as cause of PVL, mechanical prosthesis occluder malfunction, an underlying thrombus as cause of malfunction and finally presence of aortic dissection. Furthermore, CTA findings dictated treatment changes in fourteen patients (28%).

Conclusion

This study demonstrates that ECG-gated CTA has a complementary role to TEE in patients with suspected PVD. CCTA is more accurate in diagnosis of periannular complications (Aortic root abscess and Pseudo-aneurysm) and in delineating their anatomical relation to surrounding cardiac structures. Therefore CCTA can have important role in deciding and planning the method of correction whether surgical or percutaneous and has to be considered after TEE in patients with a high suspicion on PVD.

The role of cardiac computed tomography in the diagnosis of prosthetic valve endocarditis - A comparison with transthoracic and transesophageal echocardiography and intra-operative findings

BACKGROUND

Infective endocarditis is one of the most severe complications after prosthetic valve implantation and an accurate diagnosis is a clinical challenge. The purpose was to assess the diagnostic usefulness of cardiac computed tomography (CT) in valvular and perivalvular complications in patients with prosthetic valve endocarditis (PVE) and to compare CT results with transthoracic echocardiography (TTE), transesophageal echocardiography (TEE) and intraoperative findings.

METHODS

The retrospective study included 44 consecutive patients with PVE who underwent cardiac surgery. The mean age was 59.6 ± 12.9 years, 33 (75 %) were males. The presence of vegetations, abscess/pseudoaneurysm, paravalvular leakage (PVL) and inflammatory infiltration were evaluated by TTE, TEE and CT prior to surgery and the results were compared with intraoperative findings.

RESULTS

Endocarditis affected 47 valves (26 mechanical, 21 biological) in 44 patients. PVE most often affected the aortic valve (n = 36), followed by the mitral valve (n = 9) and the pulmonary valve (n = 2). In the per-valve analysis, the sensitivity of TTE, TEE and CT in diagnosing vegetations was 65 %, 91 % and 96 %; abscess 44 %, 77 % and 89 %; paravalvular leakage 90 %, 100 % and 70 %; inflammatory infiltration 39 %, 56 % and 78 %, respectively. The combination of CT and echocardiography allowed the detection of abscesses/pseudoaneurysms and inflammatory infiltration in all cases except one.

CONCLUSION

CT was superior to echocardiography in the diagnosis of paravalvular abscesses, vegetations and inflammatory infiltration. Echocardiography had a higher diagnostic value to CT in the evaluation of paravalvular leakage. Cardiac CT combined with echocardiography improves the diagnostic accuracy of PVE and both modalities should be performed.

Cardiac computed tomography in the contemporary evaluation of infective endocarditis

Increasing data have accumulated on the role of Cardiac Computed Tomography (CCT) in infective endocarditis (IE) with high accuracy for large vegetations, perivalvular complications and for exclusion of coronary artery disease to avoid invasive angiography. CCT can further help to clarify the etiology of infective prosthetic valve dysfunction (e.g. malposition, abscess, leak, vegetation or mass). Structural interventions have increased the relevance of CCT in valvular heart disease and have amplified its use. CCT may be ideally integrated into a multimodality approach that incorporates a central role of transesophageal echocardiography (TEE) with 18-FDG PET and/or cardiac magnetic resonance in individually selected cases, guided by the Heart Team. The coronavirus-19 (COVID-19) pandemic has resulted in renewed attention to CCT as a safe alternative or adjunct to TEE in selected patients. This review article provides a comprehensive, contemporary review on CCT in IE to include scan optimization, characteristics of common IE findings on CCT, published data on the diagnostic accuracy of CCT, multimodality imaging comparison, limitations and future technical advancements.

2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

This executive summary of the valvular heart disease guideline provides recommendations for clinicians to diagnose and manage valvular heart disease as well as supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from January 1, 2010, to March 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, Cochrane, Agency for Healthcare Research and Quality Reports, and other selected database relevant to this guideline. Structure: Many recommendations from the earlier valvular heart disease guidelines have been updated with new evidence and provides newer options for diagnosis and treatment of valvular heart disease. This summary includes only the recommendations from the full guideline which focus on diagnostic work-up, the timing and choice of surgical and catheter interventions, and recommendations for medical therapy. The reader is referred to the full guideline for graphical flow charts, text, and tables with additional details about the rationale for and implementation of each recommendation, and the evidence tables detailing the data considered in developing these guidelines.

Role of Cardiac CT in Infective Endocarditis: Current Evidence, Opportunities, and Challenges

Infective endocarditis (IE) can present with variable clinical and imaging findings and is associated with high morbidity and mortality. Substantial improvement of CT technology, most notably improved temporal and spatial resolution, has resulted in increased use of this modality in the evaluation of IE. The aim of this article is to review the potential role of cardiac CT in evaluating IE. Supplemental material is available for this article. © RSNA, 2021.

ECG-gated CT in Aortic Perivalvular Abscess: Comparison with Transesophageal Echocardiography and Intraoperative Findings

Background The 2015 European Society of Cardiology guidelines acknowledged similar diagnostic performance of electrocardiography (ECG)-gated CT on perivalvular abscesses compared with transesophageal echocardiography (TEE), but data on ECG-gated CT remain insufficient. Purpose To determine the diagnostic performance of ECG-gated CT for assessing aortic root perivalvular abscesses and to compare it with TEE. Materials and Methods Between January 2008 and June 2019, the imaging records of surgically confirmed infective endocarditis were retrospectively reviewed for presence of aortic perivalvular abscesses, their extension, fistulization, vegetations, and valvular destruction. The diagnostic performance of ECG-gated CT was analyzed in all patients (part A) and in an noninferiority analysis (part B; δ = -10%) in patients undergoing TEE. Results A total of 178 patients (median age, 54 years [interquartile range, 15 years]; 147 men) were evaluated (CT, n = 178; TEE, n = 35). In part A, the sensitivity and specificity of CT were 70 of 71 (99% [95% confidence interval (CI): 96%, 100%]) and 102 of 107 (95% [95% CI: 91%, 99%]) for abscess; 65 of 68 (96% [95% CI: 91%, 100%]) and 107 of 110 (97% [95% CI: 94%, 100%]) for extension, 36 of 36 (100% [95% CI: 100%, 100%]) and 139 of 142 (98% [95% CI: 96%, 100%]) for fistulization, 153 of 160 (96% [95% CI: 93%, 99%]) and five of 18 (28% [95% CI: 7%, 49%]) for vegetations, and 90 of 90 (100% [95% CI: 100%, 100%]) and 24 of 88 (27% [95% CI: 18%, 37%]) for valvular destruction. In part B, ECG-gated CT had noninferior sensitivity compared with TEE for detecting abscess (difference, 14 percentage points [lower one-sided 95% CI: -4 percentage points]), extension (difference, 0 percentage points [lower one-sided 95% CI: 0 percentage points]), fistulization (difference, 0 percentage points [lower one-sided 95% CI: 0 percentage points]), and valvular destruction (difference, 5 percentage points [lower one-sided 95% CI: -4 percentage points]). Specificity of CT was inferior for demonstrating perivalvular abscess (difference, 5 percentage points [lower one-sided 95% CI: -11 percentage points]) and valvular destruction (difference, -62 percentage points [lower one-sided 95% CI: -92 percentage points]). ECG-gated CT had inferior sensitivity in detecting vegetations (difference, -6 percentage points [lower one-sided 95% CI: -14 percentage points]). Conclusion Electrocardiography-gated CT had noninferior sensitivity compared with transesophageal echocardiography for identification of aortic perivalvular abscesses, extension of these abscesses, fistulization, and valvular destruction but had inferior sensitivity in detection of vegetations. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Sakuma in this issue.

Comparative Value of Cardiac CT and Transesophageal Echocardiography in Infective Endocarditis: A Systematic Review and Meta-Analysis

PURPOSE

To assess the comparative diagnostic accuracy of cardiac CT and transesophageal echocardiography (TEE) in the detection of valvular and perivalvular complications in infective endocarditis.

MATERIALS AND METHODS

PubMed and Embase databases were systematically searched until July 2019 for original articles published in English. Studies were included if (a) they used CT and/or TEE as an index test, (b) data were provided as infective endocarditis valvular complications (classified as abscess or pseudoaneurysm, vegetation, leaflet perforation, and paravalvular leakage), and (c) they used surgical findings as the reference standard.

RESULTS

Eight studies fulfilled the inclusion criteria. The sensitivity was higher for CT than TEE for abscess or pseudoaneurysm detection, 78% (95% confidence interval [CI]: 70%, 85%) (112 of 142) versus 69% (95% CI: 62%, 76%) (94 of 135) (P = .052) and increased to 87% (95% CI: 78%, 93%) (70 of 79) when restricted to multiphase CT studies, the difference being significant (P = .04). The sensitivity was significantly higher for TEE than CT for vegetation detection, 94% (95% CI: 92%, 96%) (363 of 383) versus 64% (95% CI: 57%, 70%) (151 of 237) (P < .001) and leaflet perforation detection, 81% (95% CI: 71%, 88%) (74 of 91) versus 41% (95% CI: 25%, 59%) (14 of 35) (P = .02).The sensitivity for paravalvular leakage was 69% (95% CI: 58%, 79%) (56 of 80) versus 44% (95% CI: 30%, 59%) (21 of 48) for TEE and CT, respectively (P = .27).

CONCLUSION

CT performs better than TEE in the detection of abscess or pseudoaneurysm whereas TEE gives superior results for vegetation detection, leaflet perforation, and paravalvular leakage.Supplemental material is available for this article.© RSNA, 2020.

Higher incidence of perivalvular abscess determines perioperative clinical outcome in patients undergoing surgery for prosthetic valve endocarditis

Background

Cardiac surgery for prosthetic valve endocarditis (PVE) is associated with substantial mortality. We aimed to analyze 30-day and 1-year outcome in patients undergoing surgery for PVE and sought to identify preoperative risk factors for mortality with special regard to perivalvular infection.

Methods

We retrospectively analyzed data of 418 patients undergoing valve surgery for infective endocarditis between January 2009 and July 2018. After 1:1 propensity matching 158 patients (79 PVE/79 NVE) were analyzed with regard to postoperative 30-day and 1-year outcomes. Univariate and multivariable analyses were performed to identify potential risk factors for mortality.

Results

315 patients (75.4%) underwent surgery for NVE and 103 (24.6%) for PVE. After propensity matching groups were comparable with regard to preoperative characteristics, clinical presentation and microbiological findings, except a higher incidence of perivalvular infection in patients with PVE (51.9%) compared to NVE (26.6%) (p = 0.001), longer cardiopulmonary bypass (166 [76–130] vs. 97 [71–125] min; p < 0.001) and crossclamp time (95 [71–125] vs. 68 [55–85] min; p < 0.001). Matched patients with PVE showed a 4-fold increased 30-day mortality (20.3%) in comparison with NVE patients (5.1%) (p = 0.004) and 2-fold increased 1-year mortality (PVE 29.1% vs. NVE 13.9%; p = 0.020). Multivariable analysis revealed perivalvular abscess, sepsis, preoperative AKI and PVE as independent risk factors for mortality. Patients with perivalvular abscess had a significantly higher 30-day mortality (17.7%) compared to patients without perivalvular abscess (8.0%) (p = 0.003) and a higher rate of perioperative complications (need for postoperative pacemaker implantation, postoperative cerebrovascular events, postoperative AKI). However, perivalvular abscess did not influence 1-year mortality (20.9% vs. 22.3%; p = 0.806), or long-term complications such as readmission rate or relapse of IE.

Conclusions

Patients undergoing surgery for PVE had a significantly higher 30-day and 1-year mortality compared to NVE. After propensity-matching 30-day mortality was still 4-fold increased in PVE compared to NVE.

Patients with perivalvular abscess showed a significantly higher 30-day mortality and perioperative complications, whereas perivalvular abscess seems to have no relevant impact on 1-year mortality, the rate of readmission or relapse of IE.

Caseous Calcification of the Mitral Annulus

Soft-tissue masses or mass-like lesions involving the mitral valve include a wide range of diseases such as tumors, abscesses, vegetations, thrombus and, rarely, caseous calcifications of the mitral annulus. Caseous calcifications of the mitral annulus is a rare variant of mitral annular calcification that is usually asymptomatic and diagnosed incidentally. Echocardiography is the first-choice imaging modality. Cardiac computed tomography is an ideal tool to confirm the presence of calcifications and caseous necrosis. In cases where there is doubt, cardiac magnetic resonance imaging may be used. We present the case of a 62-year-old patient with an intra-cardiac mass diagnosed by echocardiography. Imaging modalities to achieve a correct diagnosis and avoid unnecessary surgical intervention are discussed.

Multimodality Imaging of Complications of Cardiac Valve Surgeries

Replacement with a prosthetic heart valve (PHV) remains the definitive surgical procedure for management of severe cardiac valve disease. PHV dysfunction is uncommon but can be a life-threatening condition. The broad hemodynamic and pathophysiologic manifestations of PHV dysfunction are stenosis, regurgitation, and a stuck leaflet. Specific structural abnormalities that cause PHV dysfunction include prosthetic valve-patient mismatch, structural failure, valve calcification, dehiscence, paravalvular leak, infective endocarditis, abscess, pseudoaneurysm, abnormal connections, thrombus, hypoattenuating leaflet thickening, and pannus. Multiple imaging modalities are available for evaluating a PHV and its dysfunction. Transthoracic echocardiography is often the first-line imaging modality, with additional modalities such as transesophageal echocardiography, CT, MRI, cine fluoroscopy, and nuclear medicine used for further characterization and establishing a specific cause. The authors review PHVs and the role of imaging modalities in evaluation of PHV dysfunction and illustrate the imaging appearances of different complications. Online supplemental material is available for this article. ^©RSNA, 2019.

Value of cardiac computed tomography angiography in pre-operative assessment of infective endocarditis

Background

Substantial development of cardiac computed tomography angiography (CTA) technology in the last decade has commanded to increase usage of this modality for assessing infective endocarditis (IE). The objective of this study is to evaluate the sensitivity and specificity of preoperative cardiac CTA imaging as opposed to transthoracic echocardiography (TTE) in the assessment of complications associated to IE, with comparison to surgical findings.

Methods

Among 52 patients with surgically proven IE in our database, 24 underwent contrast-enhanced ECG cardiac CTA and were included in the study and all of them also underwent TTE.

Results

For the detection of pseudoaneurysm/abscess in both native and prosthetic valves, cardiac CTA demonstrated significantly higher sensitivity (91.5% vs. 15.8%, p < 0.0001) with similar specificity (81.25). Cardiac CTA demonstrated similar sensitivity and specificity in identifying vegetation and valvular dehiscence in all patients.

Conclusions

Preoperative cardiac CTA can be seen as complementary to TTE in assessing complications such as pseudoaneurysm or abscess of the patients with IE.

The usefulness of cardiac CT in the diagnosis of perivalvular complications in patients with infective endocarditis

Objectives

The aim of the study was to compare the usefulness of cardiac CT to transthoracic (TTE) and transesophageal (TEE) echocardiography in the diagnosis of infective endocarditis (IE) and perivalvular complications using surgical inspection as the gold standard.

Material and methods

Fifty-three consecutive patients (42 men, mean age 58.3 ± 12.5) with IE requiring surgical procedures were enrolled in the study. All patients underwent preoperative TTE, TEE, and CT. The presence of vegetations, perivalvular abscess/pseudoaneurysm, leaflet perforation, inflammatory infiltration, and prosthesis dehiscence was assessed.

Results

We analyzed 71 affected valves (58 native, 13 prosthetic). Intraoperative assessment revealed 11 abscesses/pseudoaneurysms. Sensitivity and specificity of echocardiography (TTE + TEE) and CT were 63%, 90% and 81%, 90%, respectively. The combination of CT and echocardiography allowed diagnosing all abscesses/pseudoaneurysms. Inflammatory infiltration was found intraoperatively in 15 patients. Sensitivity and specificity of TEE and CT were 53%, 94% and 46%, 100%, respectively. Intraoperative assessment revealed leaflet perforation in 16 patients. Sensitivity and specificity of TEE and CT were 75%, 79% and 43%, 89%. The sensitivity of the combination of TTE + TEE + CT was 81%. Perivalvular leakage was found in eight patients with a prosthetic valve. Sensitivity and specificity of echocardiography and CT were 100%, 100% and 88%, 100%, respectively. TEE showed higher sensitivity (97%) than CT (89%) in the diagnosis of vegetations.

Conclusions

The combination of TTE, TEE, and CT increased the sensitivity for the detection of valvular and perivalvular complications of IE.

Key Points

• CT is a useful modality in the diagnosis of IE and its local complications in addition to echocardiography.

• For the detection of abscesses and pseudoaneurysms, CT is superior to echocardiography. Combining these two modalities can increase the sensitivity of diagnosing abscess/pseudoaneurysm up to 100%.

• Adding CT to TEE increases the sensitivity for detection of inflammatory infiltrate. CT is not superior to echocardiography in diagnosing vegetations, valvular leaflet perforations, and perivalvular leaks, but it can be a useful tool when echocardiography is indeterminate.

Demonstration of infective endocarditis by cardiac CT and transoesophageal echocardiography: comparison with intra-operative findings

Aims

We aimed to compare imaging findings of infective endocarditis between computed tomography (CT) and transoesophageal echocardiography (TEE) using surgical inspection as a reference standard.

Methods and results

Forty-nine patients (aged 54 ± 17 years, 69% men) who underwent pre-operative CT and TEE for infective endocarditis were included. Twelve of these patients had prosthetic valve endocarditis. Imaging findings of infective endocarditis were classified as vegetation, leaflet perforation, abscess/pseudoaneurysm, and paravalvular leakage. Diagnostic performances of CT and TEE were evaluated using surgical inspection as a reference standard. Interobserver agreements for CT findings were obtained using Cohen's κ test. The detection rates of infective endocarditis per patient with CT and TEE were 93.9% (46/49) and 95.9% (47/49), respectively. In per-imaging analysis, the sensitivities of CT and TEE were not significantly different for both native and prosthetic valve infective endocarditis (sensitivity: vegetation, 100% in TEE and 90.9% in CT; leaflet perforation, 87.5% in TEE and 50.0% in CT; abscess/pseudoaneurysm, 40.0% in TEE and 60.0% in CT; paravalvular leakage, 100% in TEE and 50.0% in CT). Interobserver agreements for CT findings were substantial or excellent (0.79-0.88).

Conclusion

Cardiac CT can accurately demonstrate infective endocarditis in pre-operative patients with a similar diagnostic accuracy to TEE. The interobserver agreements for the CT findings of infective endocarditis were excellent.

Computed Tomography of Cardiac Valves: Review

Valvular heart disease is a common clinical problem. Although echocardiography is the standard technique for the noninvasive evaluation of the valves, cardiac CT has evolved to become a useful tool in the evaluation of the cardiac structures as well. Importantly, CT allows for improved quantification of valvular calcification due to its superior spatial resolution. It may improve the detection of small valvular or perivalvular pathology or the characterization of valvular masses and vegetations. This review describes the assessment of normal and diseased heart valves by cardiac CT and discusses its strengths and weaknesses.

Role of preoperative cardiac CT in the evaluation of infective endocarditis: comparison with transesophageal echocardiography and surgical findings

Background

Significant improvement of computed tomography (CT) technology in the last decade has led to more use of this modality for evaluating infective endocarditis (IE) especially since the introduction of high resolution electrocardiogram (ECG) synchronized multiphasic (4D) acquisition. While there are a number of reports on the accuracy and value of 4D CT for evaluation of IE, there is no published data regarding the performance of single-phase ECG gated CT for assessment of IE. The purpose of this study is to evaluate the sensitivity and specificity of preoperative single-phase ECG-gated CT imaging versus transesophageal echocardiography (TEE) in the assessment of complications related to IE, with comparison to surgical findings.

Methods

Among 899 patients with surgically proven IE in our database, 122 underwent contrast-enhanced ECG cardiac CT and were included in the study; 84 of these patients also underwent TEE.

Results

Overall, there was no significant difference between CT and TEE in the identification of pseudoaneurysm/abscess and dehiscence. For the detection of pseudoaneurysm/abscess in prosthetic valves, CT demonstrated higher sensitivity (81% vs. 64%) and specificity (75% vs. 33%) in patients with mechanical aortic valves; TEE demonstrated marginally higher sensitivity (72% vs. 63%) and specificity (80% vs. 73%) in patients with bioprosthetic aortic valves, although the differences are not statistically significant. TEE demonstrated significantly higher sensitivity (85% vs. 16%) in identifying vegetation in all patients (P<0.0001), including patients with prosthetic valves (sensitivity, 78% vs. 19%). The combined imaging findings of CT and TEE demonstrated improved sensitivity in identifying pseudoaneurysm/abscess and slightly improved detection of prosthesis dehiscence.

Conclusions

Preoperative single-phase gated CT can be seen as complementary to TEE in assessing complications of suspected IE or may be substituted for TEE when vegetation or dehiscence is depicted on transthoracic echocardiography and the patient has a contraindication to TEE.

Recommendations on nuclear and multimodality imaging in IE and CIED infections

In the latest update of the European Society of Cardiology (ESC) guidelines for the management of infective endocarditis (IE), imaging is positioned at the centre of the diagnostic work-up so that an early and accurate diagnosis can be reached. Besides echocardiography, contrast-enhanced CT (ce-CT), radiolabelled leucocyte (white blood cell, WBC) SPECT/CT and [¹⁸F]FDG PET/CT are included as diagnostic tools in the diagnostic flow chart for IE. Following the clinical guidelines that provided a straightforward message on the role of multimodality imaging, we believe that it is highly relevant to produce specific recommendations on nuclear multimodality imaging in IE and cardiac implantable electronic device infections. In these procedural recommendations we therefore describe in detail the technical and practical aspects of WBC SPECT/CT and [¹⁸F]FDG PET/CT, including ce-CT acquisition protocols. We also discuss the advantages and limitations of each procedure, specific pitfalls when interpreting images, and the most important results from the literature, and also provide recommendations on the appropriate use of multimodality imaging.

Targeting Cardiovascular Implant Infection: Multimodality and Molecular Imaging

Owing to their success in clinical practice, the prevalence of cardiovascular implants is continuously increasing. Implant infection is a relevant complication but remains a diagnostic challenge because echocardiography as a first-line test may be limited. Accordingly, a multimodality approach is increasingly used for diagnostic workup and supported by recent guidelines. As reviewed here, computed tomography and nuclear imaging provide incremental diagnostic value and may be combined in a single hybrid imaging session using positron emission tomography/computed tomography or single photon emission computed tomography/computed tomography. Molecular or cellular imaging helps to overcome the limitations of morphological imaging in implants. Larger-scale clinical studies, earlier application in the time course of diagnosis, monitoring of therapy success, technical advances, and novel radiopharmaceuticals will all contribute to sustained growth of advanced infection-targeted imaging in cardiovascular medicine.

18F-FDG-PET/CT Angiography for the Diagnosis of Infective Endocarditis

PURPOSE OF REVIEW

This article reviews the current imaging role of ¹⁸F-fluordeoxyglucose positron emission computed tomography (¹⁸F-FDG-PET/CT) combined with cardiac CT angiography (CTA) in infective endocarditis and discusses the strengths and limitations of this technique.

RECENT FINDINGS

The diagnosis of infective endocarditis affecting prosthetic valves and intracardiac devices is challenging because echocardiography and, therefore, the modified Duke criteria have well-recognized limitations in this clinical scenario. The high sensitivity of ¹⁸F-FDG-PET/CT for the detection of infection associated with the accurate definition of structural damage by gated cardiac CTA in a combined technique (PET/CTA) has provided a significant increase in diagnostic sensitivity for the detection of IE. PET/CTA has proven to be a useful diagnostic tool in patients with suspected infective endocarditis. The additional information provided by this technique improves diagnostic performance in prosthetic valve endocarditis when it is used in combination with the Duke criteria. The findings obtained in PET/CTA studies have been included as a major criterion in the recently updated diagnostic algorithm in infective endocarditis guidelines.