Are novel non-invasive imaging techniques needed in patients with suspected prosthetic heart valve endocarditis? Eur Radiol. 2015;25:2125-2133. [PMID: 25680715 PMCID: PMC4457913 DOI: 10.1007/s00330-015-3605-7]

Echocardiographic predictors and associated outcomes of multiple vegetations in infective endocarditis: A pilot study

BACKGROUND

Infective endocarditis (IE) is a life-threatening infection with an annual mortality of 40%. Embolic events reported in up to 80% of patients. Vegetations of > 10 mm size are associated with increased embolic events and poor prognosis. There is a paucity of literature on the association of multiple vegetations with outcome.

AIM

To study the echocardiographic (ECHO) features and outcomes associated with the presence of multiple vegetations.

METHODS

In this retrospective, single-center, cohort study patients diagnosed with IE were recruited from June 2017 to June 2019. A total of 84 patients were diagnosed to have IE, of whom 67 with vegetation were identified. Baseline demographic, clinical, laboratory, and ECHO parameters were reviewed. Outcomes that were studied included recurrent admission, embolic phenomenon, and mortality.

RESULTS

Twenty-three (34%) patients were noted to have multiple vegetations, 13 (56.5%) were male and 10 (43.5%) were female. The mean age of these patients was 50. Eight (35%) had a prior episode of IE. ECHO features of moderate to severe valvular regurgitation [odds ratio (OR) = 4], presence of pacemaker lead (OR = 4.8), impaired left ventricle (LV) relaxation (OR = 4), and elevated pulmonary artery systolic pressure (PASP) (OR = 2.2) are associated with higher odds of multiple vegetations. Of these moderate to severe valvular regurgitation (P = 0.028), pacemaker lead (P = 0.039) and impaired relaxation (P = 0.028) were statistically significant. These patients were noted to have an increased association of recurrent admissions (OR = 3.6), recurrent bacteremia (OR = 2.4), embolic phenomenon (OR = 2.5), intensive care unit stay (OR = 2.8), hypotension (OR = 2.1), surgical intervention (OR = 2.8) and device removal (OR = 4.8). Of this device removal (P = 0.039) and recurrent admissions (P = 0.017) were statistically significant.

CONCLUSION

This study highlights the associations of ECHO predictors and outcomes in patients with IE having multiple vegetations. ECHO features of moderate to severe regurgitation, presence of pacemaker lead, impaired LV relaxation, and elevated PASP and outcomes including recurrent admissions and device removal were found to be associated with multiple vegetations.

Role of echocardiography in the diagnosis and clinical management of infective endocarditis

Infective endocarditis (IE) is a deadly disease, constituting both diagnostic and treatment challenges. A positive outcome requires rapid and accurate diagnosis, and for that, echocardiography unequivocally remains the cornerstone. Transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) have complementary roles and have been markedly improved during the last decades. The transthoracic modality is the recommended first-line approach but may only be sufficient in patients where the probability of IE is low and/or with clear acoustic windows, especially in patients with right-sided IE. The transesophageal modality is superior to TTE in most aspects and is recommended for all other patients. Both TTE and TEE may delineate vegetation location and size, assess for paravalvular extension of infection, and have the added advantage of defining the hemodynamic effects of valvular or device infection. However, echocardiography still has significant limitations, and novel imaging techniques are increasingly being exploited to improve diagnostic potential. Cardiac computed tomography (CT) performs better than TEE in the detection of abscess or pseudoaneurysm, while magnetic resonance imaging (MRI) has limited value in the diagnostic phase of IE but adds knowledge to the evaluation of extracardiac events. Nuclear molecular techniques are evolving as key supplementary methods in difficult-to-diagnose cases. Although newer imaging modalities are undergoing preliminary evaluation and multimodal imaging will play an increasing role in IE, echocardiography will continue to be pivotal in patients with IE for the foreseeable future.

Valvulitis: a new echocardiographic criterion for the diagnosis of bioprosthetic aortic valve infective endocarditis

INTRODUCTION AND OBJECTIVES

Diffuse homogeneous hypoechoic leaflet thickening, with a wavy leaflet motion documented by transesophageal echocardiography (TEE), has been described in some cases of prosthetic valve endocarditis (PVE) involving aortic bioprosthesis (AoBio-PVE). This echocardiographic finding has been termed valvulitis. We aimed to estimate the prevalence of valvulitis, precisely describe its echocardiographic characteristics, and determine their clinical significance in patients with AoBio-PVE.

METHODS

From 2011 to 2022, 388 consecutive patients with infective endocarditis (IE) admitted to a tertiary care hospital were prospectively included in a multipurpose database. For this study, all patients with AoBio-PVE (n=86) were selected, and their TEE images were thoroughly evaluated by 3 independent cardiologists to identify all cases of valvulitis.

RESULTS

The prevalence of isolated valvulitis was 12.8%, and 20.9% of patients had valvulitis accompanied by other classic echocardiographic findings of IE. A total of 9 out of 11 patients with isolated valvulitis had significant valve stenosis, whereas significant aortic valve regurgitation was documented in only 1 patient. Compared with the other patients with AoBio-PVE, cardiac surgery was less frequently performed in patients with isolated valvulitis (27.3% vs 62.7%, P=.017). In 4 out of 5 patients with valve stenosis who did not undergo surgery but underwent follow-up TEE, valve gradients significantly improved with appropriate antibiotic therapy.

CONCLUSIONS

Valvulitis can be the only echocardiographic finding in infected AoBio and needs to be identified by imaging specialists for early diagnosis. However, this entity is a diagnostic challenge and additional imaging techniques might be required to confirm the diagnosis. Larger series are needed.

Multimodality Imaging for the Assessment of Mitral Valve Disease

Mitral valve disease is the most common valvular heart disease. Imaging determines the etiology (anatomic assessment), valve function and severity of valvular heart disease (hemodynamic assessment), remodeling of the left ventricle and right ventricle, and preplanning and guidance of percutaneous intervention. Although roles of computed tomography and magnetic resonance are increasing, echocardiography serves as the first-line imaging modality for the diagnosis and serial follow-up in most cases. This review summarizes the roles of multimodality imaging currently available from research fields to daily clinical practice.

Contemporary applications of multimodality imaging in infective endocarditis

INTRODUCTION

Infective endocarditis (IE) is an increasingly important condition with significant morbidity and mortality. With advancements in cardiovascular interventions including prosthetic valve implantation and utilization of intracardiac devices, the prevalence of IE is rising in the modern era. Early detection and management of this condition are critical.

AREAS COVERED

This review presents a contemporary review of the applications of multi-modality imaging in IE, taking a comparative approach of the various imaging modalities.

EXPERT OPINION

Transthoracic and transesophageal echocardiography are essential imaging modalities in establishing the diagnosis of IE, as well as evaluating for complications of IE. Other imaging modalities such as cardiac computed tomography and nuclear imaging play an important role as adjuvant imaging modalities for the evaluation of IE, particularly in prosthetic valve IE and cardiovascular implantable device associated IE. It is crucial to understand the strengths, weaknesses, and clinical application of each imaging modality, to improve the diagnosis, management, and outcomes of patients with IE.

18F- FDG PET/CT in reclassifying the probable diagnosis of IE - A review

In the diagnosis of infective endocarditis (IE), Modified Duke's criteria, coupled with clinical suspicion, serve as the guiding framework. For cases involving prosthetic valve endocarditis and infections affecting implantable devices, the use of metabolic imaging with 18 F-FDG PET/CT scans has gained prominence, as per the recommendations of the European Society of Cardiology guidelines. This imaging modality enhances sensitivity and specificity by identifying infective foci within the heart and extracardiac locations. Early utilization of these scans is crucial for confirming or ruling out IE, although caution is required to mitigate false positive responses, especially in the presence of ongoing inflammatory activity. A standardized ratio of ≥2.0 between FDG uptake around infected tissues and the blood pool has demonstrated a sensitivity of 100 % and specificity of 91 %. It is noteworthy that the sensitivity of FDG PET/CT varies, being lower for native valve and lead infections but considerably higher for prosthetic valve and pulse generator infections. This review provides a comprehensive overview of the advantages offered by FDG PET/CT in achieving a definitive diagnosis of IE.

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.

Multimodality imaging in marantic endocarditis associated with cancer: a multicentric cohort study

AIMS

We aimed to assess the role of multimodality imaging (MMI) in the diagnosis of marantic endocarditis (ME) associated with cancers and to describe the clinical characteristics, management, and outcome of these patients.

METHODS AND RESULTS

In a retrospective multicentric study including four tertiary centres for the treatment of endocarditis in France and Belgium, patients with a diagnosis of ME were included. Demographic, MMI [echocardiography, computed tomography (CT), and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT)], and management data were collected. Long-term mortality was analysed. Between November 2011 and August 2021, 47 patients with a diagnosis of ME were included. Mean age was 65 ± 11 years. ME occurred in 43 cases (91%) on native valves. Vegetations were detected by echocardiography in all cases and in 12 cases (26%) by CT. No patient had an increased cardiac 18F-FDG valve uptake. The most common cardiac valve involved was aortic (34 cases, 73%). Twenty-two patients (46%) had a known cancer before ME, and 25 cases (54%) were diagnosed thanks to multimodality imaging. 18FDG PET/CT was performed in 30 patients (64%) and allowed a new diagnosis of cancer in 14 patients (30%). Systemic embolism was frequent (40 patients, 85% of cases). Forty-one patients (87%) were treated medically with anticoagulation therapy. One-year mortality was 55% (26 patients).

CONCLUSION

ME remains associated with a high risk of complications and death.

Infection Imaging: Focus on New Tracers?

Infections account for relevant morbidity and mortality, especially if the cardiovascular system is affected. Clinical manifestations are often unspecific, resulting in a challenging diagnostic work-up. The use of molecular imaging methods, namely [18F]FDG PET and leukocyte scintigraphy, is increasingly recognized in recently published international guidelines. However, these 2 established methods focus on the host's immune response to the pathogen and are therefore virtually unable to differentiate infection from inflammation. Targeting the microorganism responsible for the infection directly with novel imaging agents is a promising strategy to overcome these limitations. In this review, we discuss clinically approved [18F]FDG PET with its advantages and limitations in cardiovascular infections, followed by new PET-based approaches for the detection of cardiovascular infections by bacteria-specific molecular imaging methods. A multitude of different targeting options has already been preclinically evaluated, but most still lack clinical translation. We give an overview not only on promising tracer candidates for noninvasive molecular imaging of infections but also on issues hampering clinical translation.

Contemporary Features and Management of Endocarditis

Infective endocarditis is a rare but devastating disease. Morbidity and mortality rates have failed to improve despite new technological advances. The disease has evolved over time with new significant populations at risk-most notably those with prosthetic valves or implantable cardiovascular devices. These devices pose new challenges for achieving a timely and accurate diagnosis of infection. While the modified Duke criteria is accepted as the gold standard for diagnosing native valve endocarditis, it has been shown to have significantly inferior sensitivity when it comes to identifying infections related to right-heart endocarditis, prosthetic valves, and indwelling cardiac devices. Additionally, prosthetic valves and cardiovascular implantable electronic devices can exhibit shadowing and artifact, rendering transthoracic echocardiography and transesophageal echocardiography results inconclusive or even normal. Having a keen awareness of the varying clinical presentations, as well as emerging valvular imaging modalities such as F-fluorodeoxyglucose cardiac positron-emission tomography plus computed tomography, promises to improve the evaluation and diagnosis of infective endocarditis. However, indications for appropriate use of these studies and guidance on modern clinical management are still needed.

Early Biological Valve Failure: Structural Valve Degeneration, Thrombosis, or Endocarditis?

Biological valve failure (BVF) is an inevitable condition that compromises the durability of biological heart valves (BHVs). It stems from various causes, including rejection, thrombosis, and endocarditis, leading to a critical state of valve dysfunction. Echocardiography, cardiac computed tomography, cardiac magnetic resonance, and nuclear imaging play pivotal roles in the diagnostic multimodality workup of BVF. By providing a comprehensive overview of the pathophysiology of BVF and the diagnostic approaches in different clinical scenarios, this review aims to aid clinicians in their decision-making process. The significance of early detection and appropriate management of BVF cannot be overstated, as these directly impact patients' prognosis and their overall quality of life. Ensuring timely intervention and tailored treatments will not only improve outcomes but also alleviate the burden of this condition on patients' life. By prioritizing comprehensive assessments and adopting the latest advancements in diagnostic technology, medical professionals can significantly enhance their ability to manage BVF effectively.

Evaluation of causal heart diseases in cardioembolic stroke by cardiac computed tomography

Cardioembolic stroke is a potentially devastating condition and tends to have a poor prognosis compared with other ischemic stroke subtypes. Therefore, it is important for proper therapeutic management to identify a cardiac source of embolism in stroke patients. Cardiac computed tomography (CCT) can detect the detailed visualization of various cardiac pathologies in the cardiac chambers, interatrial and interventricular septum, valves, and myocardium with few motion artifacts and few dead angles. Multiphase reconstruction images of the entire cardiac cycle make it possible to demonstrate cardiac structures in a dynamic manner. Consequently, CCT has the ability to provide high-quality information about causal heart disease in cardioembolic stroke. In addition, CCT can simultaneously evaluate obstructive coronary artery disease, which may be helpful in surgical planning in patients who need urgent surgery, such as cardiac tumors or infective endocarditis. This review will introduce the potential clinical applications of CCT in an ischemic stroke population, with a focus on diagnosing cardioembolic sources using CCT.

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.

Radionuclide Imaging of Infective Endocarditis

Infective endocarditis (IE) is associated with high morbidity and mortality. Early diagnosis is crucial for adequate patient management. Due to difficulties in the diagnosis, a multidisciplinary discussion in addition to the integration of clinical signs, microbiology data, and imaging data is used. Imaging, including echocardiography, molecular imaging techniques, and coronary CT angiography (CTA) is central to detect infections involving heart valves and implanted cardiovascular devices, also allowing for early detection of septic emboli and metastatic. This article describes the main clinical application of white blood cell SPECT/CT and [¹⁸F]FDG-PET/CT and CTA in IE and infections associated with cardiovascular implantable electronic devices.

Diagnostic performance of contemporary transesophageal echocardiography with modern imaging for infective endocarditis

Background

Infective endocarditis (IE) is associated with high morbidity and mortality. Following an initial negative transesophageal echocardiogram (TEE), high clinical suspicion warrants repeat examination. We evaluated the diagnostic performance of contemporary TEE imaging for IE.

Methods

This retrospective cohort study included patients ≥18 years old undergoing ≥2 TEEs within 6 months, with confirmed diagnosis of IE based on Duke criteria, 70 in 2011 and 172 in 2019, were included. We compared the diagnostic performance of TEE for IE in 2019 versus 2011. The primary endpoint was the sensitivity of initial TEE to detect IE.

Results

Sensitivity of the initial TEE to detect endocarditis was 85.7% versus 95.3%, in 2011 and 2019, respectively (P=0.01). On multivariable analysis, initial TEE more frequently detected IE in 2019, compared to 2011 [odds ratio (OR): 4.06, 95% confidence intervals (CIs): 1.41-11.71, P=0.01]. Improved diagnostic performance was driven by improved detection of prosthetic valve infective endocarditis (PVIE), sensitivity 70.8% in 2011 versus 93.7% (P=0.009) in 2019. In 2019, TEEs more frequently utilized probes with higher frame rates/resolution, than 2011 (P<0.001). Three dimensional (3D) technology was utilized in 97.2% of initial TEEs in 2019, compared to 70.5% in 2011 (P<0.001).

Conclusions

Contemporary TEE was associated with improved diagnostic performance for endocarditis, driven by improved sensitivity for PVIE.

Contemporary Review of Multi-Modality Cardiac Imaging Evaluation of Infective Endocarditis

Infective endocarditis (IE) remains to be a heterogeneous disease with high morbidity and mortality rates, which can affect native valves, prosthetic valves, and intra-cardiac devices, in addition to causing systemic complications. The combination of clinical, laboratory, and cardiac imaging evaluation is critical for early diagnosis and risk stratification of IE. This can facilitate timely medical and surgical management to improve patient outcomes. Key imaging findings for IE include vegetations, valve perforation, prosthetic valve dehiscence, pseudoaneurysms, abscesses, and fistulae. Transthoracic echocardiography continues to be the first-line imaging modality of choice, while transesophageal echocardiography subsequently provides an improved structural assessment and characterization of lesions to facilitate management decision in IE. Recent advances in other imaging modalities, especially cardiac computed tomography and 18F-fluorodeox-yglucose positron emission tomography, and to a lesser extent cardiac magnetic resonance imaging and other nuclear imaging techniques, have demonstrated important roles in providing complementary IE diagnostic and prognostic information. This review aims to discuss the individual and integrated utilities of contemporary multi-modality cardiac imaging for the assessment and treatment guidance of IE.

Prosthetic Aortic Valve Endocarditis Creeping Into the Paravalvular Space

Prosthetic valve endocarditis is a devastating infection with a challenging diagnosis and management. Despite advances in its diagnostic modalities, medical, and surgical interventions, prosthetic valve endocarditis still carries high morbidity and mortality rates. Here, we report a case of prosthetic aortic valve endocarditis that progressed to involve the paravalvular space and the importance of multimodality cardiac imaging in the early detection of paravalvular complications.

Evidence of clinical impact supports a new petition for Medicare coverage of 18F-FDG-PET/CT in the evaluation of Staphylococcus aureus bacteremia: a focused literature review and call to action

Staphylococcus aureus bacteremia (SAB) causes considerable morbidity and mortality and requires comprehensive assessment for metastatic infection. The roles of routine imaging beyond echocardiography in SAB, including 18F-FDG-PET/CT, remain contentious. We performed a literature review of studies reporting impact of 18F-FDG-PET/CT on the clinical management or outcomes of SAB published through 3/1/2022. We identified seven observational studies, in which 18F-FDG-PET/CT frequently identified metastatic foci of infection, revealed foci undetected by prior investigations, led to additional source control procedures, and was associated with fewer infection relapses and lower mortality. Calculated numbers needed to treat (NNTs) for receipt of 18F-FDG-PET/CT were 7-9 to change antimicrobial therapy, 10-27 to lead to an additional source control procedure, and 4-8 to prevent death. These data are comparable to the evidence for clinical impact of other diagnostic modalities accepted as standard of care in SAB, and form a compelling basis for advocacy to expand access to 18F-FDG-PET/CT.

Cardiac Imaging for Diagnosis and Management of Infective Endocarditis

Imaging is central to the care of patients with infective endocarditis. While transthoracic and transesophageal echocardiography are the principle imaging techniques, additional modalities including positron emission tomography and cardiac computed tomography, and to a lesser extent intracardiac echocardiography, play an increasing role. This review discusses the role of cardiac imaging in establishing the diagnosis of endocarditis, in predicting its embolic risk and in making decisions regarding the need for and timing of surgery.

Nuclear Imaging in Infective Endocarditis

Infective endocarditis (IE) is a life-threatening disease with stable prevalence despite prophylactic, diagnostic, and therapeutic advances. In parallel to the growing number of cardiac devices implanted, the number of patients developing IE on prosthetic valves and cardiac implanted electronic device (CIED) is increasing at a rapid pace. The diagnosis of IE is particularly challenging, and currently relies on the Duke-Li modified classification, which include clinical, microbiological, and imaging criteria. While echocardiography remains the first line imaging technique, especially in native valve endocarditis, the incremental value of two nuclear imaging techniques, ¹⁸F-fluorodeoxyglucose positron emission tomography with computed tomography (¹⁸F-FDG-PET/CT) and white blood cells single photon emission tomography with computed tomography (WBC-SPECT), has emerged for the management of prosthetic valve and CIED IE. In this review, we will summarize the procedures for image acquisition, discuss the role of ¹⁸F-FDG-PET/CT and WBC-SPECT imaging in different clinical situations of IE, and review the respective diagnostic performance of these nuclear imaging techniques and their integration into the diagnostic algorithm for patients with a suspicion of IE.

Best Practices for Imaging Cardiac Device-Related Infections and Endocarditis: A JACC: Cardiovascular Imaging Expert Panel Statement

The diagnosis of cardiac device infection and, more importantly, accurate localization of the infection site, such as defibrillator pocket, pacemaker lead, along the peripheral driveline or central portion of the left ventricular assist device, prosthetic valve ring abscesses, and perivalvular extensions, remain clinically challenging. Although transthoracic and transesophageal echocardiography are the first-line imaging tests in suspected endocarditis and for assessing hemodynamic complications, recent studies suggest that cardiac computed tomography (CT) or CT angiography and functional imaging with ¹⁸F-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) with CT (FDG PET/CT) may have an incremental role in technically limited or inconclusive cases on echocardiography. One of the key benefits of FDG PET/CT is in its detection of inflammatory cells early in the infection process, before morphological damages ensue. However, there are many unanswered questions in the literature. In this document, we provide consensus on best practices among the various imaging studies, which includes the detection of cardiac device infection, differentiation of infection from inflammation, image-guided patient management, and detailed recommendations on patient preparation, image acquisition, processing, interpretation, and standardized reporting.

Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021

BACKGROUND

 Transcatheter aortic valve implantation (TAVI) has gained worldwide acceptance and implementation as an alternative therapeutic option in patients with severe aortic valve stenosis unable to safely undergo surgical aortic valve replacement. This transformative technique places the radiologist in a key position in the pre-procedural assessment of potential candidates for this technique, delivering key anatomical information necessary for patient eligibility and procedural safety. Recent trials also provide encouraging results to potentially extend the indication to patients with safer risk profiles.

METHOD

 The review is based on a PubMed literature search using the search terms "transcatheter heart valve", "TAVI", "TAVR", "CT", "imaging", "MR" over a period from 2010-2020, combined with personal comments based on the author's experience.

RESULTS AND CONCLUSION

 CT plays a prominent role in the pre-procedural workup, delivering as a true 3D imaging modality optimal visualization of the complex anatomy of the aortic root with simultaneous evaluation of the patency of the different access routes. As such, the contribution of CT is key for the determination of patient eligibility and procedural safety. This input is supplementary to the contributions of other imaging modalities and forms an important element in the discussions of the Heart Valve Team. Knowledge of the procedure and its characteristics is necessary in order to provide a comprehensive and complete report. While the role of CT in the pre-procedural evaluation is well established, the contribution of CT and MR and the clinical significance of their findings in the routine follow-up after the intervention are less clear and currently the subject of intense investigation. Important issues remain, including the occurrence and significance of subclinical leaflet thrombosis, prosthetic heart valve endocarditis, and long-term structural valve degeneration.

KEY POINTS

  · CT plays a crucial role in evaluating transcatheter heart valve candidates. · Evaluation must include the dimensions of the aortic root and access paths. · The exact post-procedural role of CT and MRI has not yet been determined..

CITATION FORMAT

· Salgado R, El Addouli H, Budde RP. Transcatheter Aortic Valve Implantation: The Evolving Role of the Radiologist in 2021. Fortschr Röntgenstr 2021; 193: 1411 - 1425.

Diagnostic Challenges in Sepsis

Purpose of Review

Sepsis is a leading cause of death worldwide. Groundbreaking international collaborative efforts have culminated in the widely accepted surviving sepsis guidelines, with iterative improvements in management strategies and definitions providing important advances in care for patients. Key to the diagnosis of sepsis is identification of infection, and whilst the diagnostic criteria for sepsis is now clear, the diagnosis of infection remains a challenge and there is often discordance between clinician assessments for infection.

Recent Findings

We review the utility of common biochemical, microbiological and radiological tools employed by clinicians to diagnose infection and explore the difficulty of making a diagnosis of infection in severe inflammatory states through illustrative case reports. Finally, we discuss some of the novel and emerging approaches in diagnosis of infection and sepsis.

Summary

While prompt diagnosis and treatment of sepsis is essential to improve outcomes in sepsis, there remains no single tool to reliably identify or exclude infection. This contributes to unnecessary antimicrobial use that is harmful to individuals and populations. There is therefore a pressing need for novel solutions. Machine learning approaches using multiple diagnostic and clinical inputs may offer a potential solution but as yet these approaches remain experimental.

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.

Multimodality imaging in the diagnosis and management of prosthetic valve endocarditis: A contemporary narrative review

Infective endocarditis is one of the leading life-threatening infections around the world. With the exponential growth in the field of transcatheter interventions and advances in specialized surgical techniques, the number of prosthetic valves and cardiac implantable devices has significantly increased. This has led to a steep rise in the number of cases of prosthetic valve endocarditis (PVE) comprising up to 30% of all cases. Clinical guidelines rely on the use of the modified Duke criteria; however, the diagnostic sensitivity of the modified Duke criteria is reduced in the context of PVE. This is in part attributed to prosthesis related artifact which greatly affects the ability of echocardiography to detect early infective changes related to PVE in certain cases. There has been increasing recognition of the roles of complementary imaging modalities and updates in international society recommendations. Prompt diagnosis and treatment can prevent the devastating consequences of this condition. Imaging modalities such as cardiac computed tomography and ¹⁸-fluorodeoxyglucose positron emission tomography/computed tomography are diagnostic tools that provide a complementary role to echocardiography in aiding diagnosis, pre-operative planning, and treatment decision-making process in these challenging cases. Understanding the strengths and limitations of these adjuvant imaging modalities is crucial for the implementation of appropriate imaging modalities in clinical practice.

EACVI recommendations on cardiovascular imaging for the detection of embolic sources: endorsed by the Canadian Society of Echocardiography

Cardioaortic embolism to the brain accounts for approximately 15-30% of ischaemic strokes and is often referred to as 'cardioembolic stroke'. One-quarter of patients have more than one cardiac source of embolism and 15% have significant cerebrovascular atherosclerosis. After a careful work-up, up to 30% of ischaemic strokes remain 'cryptogenic', recently redefined as 'embolic strokes of undetermined source'. The diagnosis of cardioembolic stroke remains difficult because a potential cardiac source of embolism does not establish the stroke mechanism. The role of cardiac imaging-transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), cardiac computed tomography (CT), and magnetic resonance imaging (MRI)-in the diagnosis of potential cardiac sources of embolism, and for therapeutic guidance, is reviewed in these recommendations. Contrast TTE/TOE is highly accurate for detecting left atrial appendage thrombosis in patients with atrial fibrillation, valvular and prosthesis vegetations and thrombosis, aortic arch atheroma, patent foramen ovale, atrial septal defect, and intracardiac tumours. Both CT and MRI are highly accurate for detecting cavity thrombosis, intracardiac tumours, and valvular prosthesis thrombosis. Thus, CT and cardiac magnetic resonance should be considered in addition to TTE and TOE in the detection of a cardiac source of embolism. We propose a diagnostic algorithm where vascular imaging and contrast TTE/TOE are considered the first-line tool in the search for a cardiac source of embolism. CT and MRI are considered as alternative and complementary tools, and their indications are described on a case-by-case approach.

Expert opinion paper on cardiac imaging after ischemic stroke

This expert opinion paper on cardiac imaging after acute ischemic stroke or transient ischemic attack (TIA) includes a statement of the "Heart and Brain" consortium of the German Cardiac Society and the German Stroke Society. The Stroke Unit-Commission of the German Stroke Society and the German Atrial Fibrillation NETwork (AFNET) endorsed this paper. Cardiac imaging is a key component of etiological work-up after stroke. Enhanced echocardiographic tools, constantly improving cardiac computer tomography (CT) as well as cardiac magnetic resonance imaging (MRI) offer comprehensive non- or less-invasive cardiac evaluation at the expense of increased costs and/or radiation exposure. Certain imaging findings usually lead to a change in medical secondary stroke prevention or may influence medical treatment. However, there is no proof from a randomized controlled trial (RCT) that the choice of the imaging method influences the prognosis of stroke patients. Summarizing present knowledge, the German Heart and Brain consortium proposes an interdisciplinary, staged standard diagnostic scheme for the detection of risk factors of cardio-embolic stroke. This expert opinion paper aims to give practical advice to physicians who are involved in stroke care. In line with the nature of an expert opinion paper, labeling of classes of recommendations is not provided, since many statements are based on expert opinion, reported case series, and clinical experience.

Multimodality Imaging for the Assessment of Mitral Valve Disease

Mitral valve disease is the most common valvular heart disease. Imaging determines the etiology (anatomic assessment), valve function and severity of valvular heart disease (hemodynamic assessment), remodeling of the left ventricle and right ventricle, and preplanning and guidance of percutaneous intervention. Although roles of computed tomography and magnetic resonance are increasing, echocardiography serves as the first-line imaging modality for the diagnosis and serial follow-up in most cases. This review summarizes the roles of multimodality imaging currently available from research fields to daily clinical practice.

Usefulness of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Diagnosis of Infective Endocarditis in Patients With Adult Congenital Heart Disease

BACKGROUND

Infective endocarditis (IE) in patients with adult congenital heart disease (ACHD) remains a diagnostic challenge due to difficulties in detecting endocardial lesions by echocardiography. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) has shown good diagnostic performance in prosthetic valve IE. This study aimed to assess its additional diagnostic value in ACHD-associated IE and to characterize its advantages.Methods and Results:Overall, 22 patients with ACHD and clinical suspicion of IE were retrospectively studied. ¹⁸F-FDG PET/CT was performed in addition to conventional assessment based on the modified Duke criteria. The final IE diagnosis was determined by an expert team during a 3-month clinical course, resulting in 18 patients diagnosed with IE. Seven patients (39%) were diagnosed with definite IE only by initial echocardiography. An ¹⁸F-FDG PET/CT assessment revealed endocardial involvement in the other 9 patients, resulting in the diagnosis of definite IE in 16 in total (88%). Right-sided endocardial lesions were more common (n=12, 67%) but rarely identified by echocardiography, whereas ¹⁸F-FDG PET/CT revealed right-sided lesions in 9 patients. A negative ¹⁸F-FDG PET/CT (n=7, 39%) assessment was associated with a native valve IE (71% vs. 0%). In 4 patients who were identified with not-IE, neither echocardiography nor ¹⁸F-FDG PET/CT detected any suspicious cardiac involvement.

CONCLUSIONS

In the diagnosis of ACHD-associated IE, characterized by right-sided IE, ¹⁸F-FDG PET/CT assessment should be useful.

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.

Endocarditis in Patients with Aortic Valve Prosthesis: Comparison between Surgical and Transcatheter Prosthesis

The interventional treatment of aortic stenosis is currently based on transcatheter aortic valve implantation/replacement (TAVI/TAVR) and surgical aortic valve replacement (SAVR). Prosthetic valve infective endocarditis (PVE) is the most worrisome complication after valve replacement, as it still carries high mortality and morbidity rate. Studies have not highlighted the differences in the occurrence of PVE in SAVR as opposed to TAVR, but the reported incidence rates are widely uneven. Literature portrays different microbiological profiles for SAVR and TAVR PVE: Staphylococcus, Enterococcus, and Streptococcus are the pathogens that are more frequently involved with differences regarding the timing from the date of the intervention. Imaging by means of transoesophageal echocardiography, and computed tomography (CT) Scan is essential in identifying vegetations, prosthesis dysfunction, dehiscence, periannular abscess, or aorto-ventricular discontinuity. In most cases, conservative medical treatment is not able to prevent fatal events and surgery represents the only viable option. The primary objectives of surgical treatment are radical debridement and the removal of infected tissues, the reconstruction of cardiac and aortic morphology, and the restoration of the aortic valve function. Different surgical options are discussed. Fast diagnosis, the adequacy of antibiotics treatment, and prompt interventions are essential in preventing the negative consequences of infective endocarditis (IE).

A narrative review of the interpretation of guidelines for the treatment of infective endocarditis

The recommendations of the current guidelines and the position papers of professional societies from the European Society of Cardiology/European Society of Cardiothoracic Surgeons (ESC), the American College of Cardiology/American Heart Association/Society of Thoracic Surgeon (ACC/AHA/STS) and American Association of Thoracic Surgeon (AATS) regarding management of patients with valvular heart endocarditis were updated over the past decade. However, some of the recommendations appear to contradict one another. Given the changing paradigms on how the disease manifests, our aim was to review the respective guidelines and highlight these differences whilst drawing attention to the subsequent studies from which they were derived. In particular, concerns regarding antibiotic prophylaxis and therapy, imaging modality for diagnosis and follow-up, cerebrovascular sequalae and timing of surgery are appraised in detail. We also identified the novel techniques used such as transcatheter therapies and advances in imaging modalities used for diagnosis and treatment of this condition. The lack of randomised control trials (RCTs) does raise several issues regarding applicability of findings in day-to-day practice. Therefore, the focus of upcoming studies should be on clearly defined multicenter RCTs to provide more robust evidence for the management and treatment of infective endocarditis as future guidelines will be based on the outcomes of these trials.

Infective endocarditis - A review of current therapy and future challenges

Etiological, microbiological and epidemiological factors changed over time, but mortality rates remain high in infective endocarditis (IE). Healthcare-associated IE is nowadays responsible for a significant proportion of cases due to increasing numbers of cardiac devices. Cardiac implantable electronic devices, transcatheter aortic valve replacement, and percutaneous valve repair are meanwhile used, especially in old and sick patients. In suspected IE modified Duke criteria, integrating clinical results, imaging, and biomarkers are traditionally applied. Newer imaging technologies such as multi-slice computed tomography, photon-emission computed tomography, and magnetic resonance imaging might add value to conventional echocardiography in diagnosis and management of IE. Treatment consists of long-term antibiotic therapy, infectiological source control and/or cardiac surgery. Recently, antibiotic parenteral outpatient regimens and partial oral treatment strategies were shown to shorten hospital stays in patients suffering from IE. However, it remains unclear how to best select patients for partial oral therapy. This review describes new trends in diagnosing, imaging, and treating IE in a changing patient collective with particular focus on patients with implantable cardiac devices.

Cardiac Imaging After Ischemic Stroke or Transient Ischemic Attack

PURPOSE OF REVIEW

Cardiac imaging after ischemic stroke or transient ischemic attack (TIA) is used to identify potential sources of cardioembolism, to classify stroke etiology leading to changes in secondary stroke prevention, and to detect frequent comorbidities. This article summarizes the latest research on this topic and provides an approach to clinical practice to use cardiac imaging after stroke.

RECENT FINDINGS

Echocardiography remains the primary imaging method for cardiac work-up after stroke. Recent echocardiography studies further demonstrated promising results regarding the prediction of non-permanent atrial fibrillation after ischemic stroke. Cardiac magnetic resonance imaging and computed tomography have been tested for their diagnostic value, in particular in patients with cryptogenic stroke, and can be considered as second line methods, providing complementary information in selected stroke patients. Cardiac imaging after ischemic stroke or TIA reveals a potential causal condition in a subset of patients. Whether systematic application of cardiac imaging improves outcome after stroke remains to be established.

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.

Repeat transesophageal echocardiography in infective endocarditis: An analysis of contemporary utilization

BACKGROUND

Current guidelines from the American Heart Association (AHA) recommend repeating transesophageal echocardiography (TEE) in three to five days if there is high suspicion of IE despite an initial TEE that was negative. This recommendation, however, is based on limited published data.

OBJECTIVES

This investigation attempts to identify specific factors that prompted repeat TEE and evaluate the yield of IE-related findings demonstrated by repeat TEE as compared to initial or prior TEE.

METHODS

A retrospective cohort who had at least one repeat TEE during an index hospitalization or initial course of antimicrobial therapy for IE between January 2014 and September 2018. We assessed the impact of repeat TEE on IE diagnosis and patient management and included a comparative analysis of patients with initial TEE only.

RESULTS

Overall, 59 (44.7%) of 132 IE patients underwent repeat TEE. In a comparative analysis that involved patients who had undergone an initial TEE only versus those who had repeat TEE, male gender (P = .029) and presence of a prosthetic valve or annuloplasty ring (P = .017) were significantly associated with repeat TEE. Importantly, 8 (17.4%) of repeat TEE were critical for IE diagnosis, 8 (17.4%) impacted antimicrobial management, and 11 (23.9%) supported cardiovascular surgical intervention.

CONCLUSIONS

From a population-based cohort of incident IE cases, repeat TEE was more frequently (44.7%) done in patients with suspect or proven IE and associated complications than anticipated. Repeat TEE remains pivotal in a contemporary practice that involves critical aspects of IE diagnosis and management.

Imaging of the aortic root on high-pitch non-gated and ECG-gated CT: awareness is the key!

The aortic pathologies are well recognized on imaging. However, conventionally cardiac and proximal aortic abnormalities were only seen on dedicated cardiac or aortic studies due to need for ECG gating. Advances in CT technology have allowed motionless imaging of the chest and abdomen, leading to an increased visualization of cardiac and aortic root diseases on non-ECG-gated imaging. The advances are mostly driven by high pitch due to faster gantry rotation and table speed. The high-pitch scans are being increasingly used for variety of clinical indications because the images are free of motion artifact (both breathing and pulsation) as well as decreased radiation dose. Recognition of aortic root pathologies may be challenging due to lack of familiarity of radiologists with disease spectrum and their imaging appearance. It is important to recognize some of these conditions as early diagnosis and intervention is key to improving prognosis. We present a comprehensive review of proximal aortic anatomy, pathologies commonly seen at the aortic root, and their imaging appearances to familiarize radiologists with the diseases of this location.

Infective endocarditis complicating transcatheter aortic valve implantation

Infective endocarditis complicating transcatheter aortic valve implantation (TAVI-IE) is a relatively rare condition with an incidence of 0.2%–3.1% at 1 year post implant. It is frequently caused by Enterococci, Staphylococcus aureus and coagulase negative staphylococci. While the incidence currently appears to be falling, the absolute number of cases is likely to rise substantially as TAVI expands into low risk populations following the publication of the PARTNER 3 and Evolut Low Risk trials. Important risk factors for the development of TAVI-IE include a younger age at implant and significant residual aortic regurgitation. The echocardiographic diagnosis of TAVI-IE can be challenging, and the role of supplementary imaging techniques including multislice computed tomography (MSCT) and positron emission tomography (18FDG PET) is still emerging. Treatment largely parallels that of conventional prosthetic valve endocarditis (PVE), with prolonged intravenous antibiotic therapy and consideration of surgical intervention forming the cornerstones of management. The precise role and timing of cardiac surgery in TAVI-IE is yet to be defined, with a lack of clear evidence to help identify which patients should be offered surgical intervention. Minimising unnecessary healthcare interventions (both during and after TAVI) and utilising appropriate antibiotic prophylaxis may have a role in preventing TAVI-IE, but robust evidence for specific preventative strategies is lacking. Further research is required to better select patients for advanced hybrid imaging, to guide surgical management and to inform prevention in this challenging patient cohort.

Three dimensional transesophageal echocardiography: a missing link in infective endocarditis imaging?

The role of two dimensional (2D) echocardiography (ECHO) for the diagnosis and clinical decision making in infective endocarditis (IE) has been extensively studied and described in the medical literature. Some reports have demonstrated the incremental value of three dimensional (3D) transesophageal (TE) ECHO in the setting of IE. However, a systematic review focusing on the role of 3D imaging is lacking. In this manuscript, we examine the role of 3D TE ECHO in the diagnosis of IE. IE is a challenging disease in which 2D transthoracic (TT) and TE ECHO have complementary roles and are unequivocally the mainstay of diagnostic imaging. Still, 2D imaging has important limitations. Technological advances in 3D imaging allow for the reconstruction of real-time anatomical images of cardiac structure and function. 3D imaging has emerged as a diagnostic technique that overcame some of the limitations of 2D ECHO. Currently, both transthoracic and transesophageal echocardiography transducers are able to generate 3D images. However, 3D TE ECHO provides images of a higher quality in comparison to 3D TT ECHO, and is the best echocardiographic modality able to allow for a detailed anatomical imaging. 3D TE ECHO may represent the key adjunctive echocardiographic technique being able to positively impact on IE-related surgical planning and intervention and to facilitate the interaction between the surgeon and the imaging specialist. Importantly, 3D TE ECHO is not the recommended initial modality of choice for the diagnosis of IE; however, in highly specialized centers, it has become an important complementary technique when advanced surgical planning is required. Furthermore, anatomical imaging has become the link between the different techniques that play a role in IE imaging. In fact, both computed tomography and magnetic resonance allow three dimensional reconstruction. An important future goal should allow for the fusion among various imaging modalities. Our review highlights the role of 3D TE ECHO in IE imaging and emphasize where it offers incremental value.

Improving the Diagnostic Performance of 18F-Fluorodeoxyglucose Positron-Emission Tomography/Computed Tomography in Prosthetic Heart Valve Endocarditis

BACKGROUND

¹⁸F-Fluorodeoxyglucose (FDG) positron-emission tomography/computed tomography (PET/CT) was recently introduced as a new tool for the diagnosis of prosthetic heart valve endocarditis (PVE). Previous studies reporting a modest diagnostic accuracy may have been hampered by unstandardized image acquisition and assessment, and several confounders, as well. The aim of this study was to improve the diagnostic performance of FDG PET/CT in patients in whom PVE was suspected by identifying and excluding possible confounders, using both visual and standardized quantitative assessments.

METHODS

In this multicenter study, 160 patients with a prosthetic heart valve (median age, 62 years [43-73]; 68% male; 82 mechanical valves; 62 biological; 9 transcatheter aortic valve replacements; 7 other) who underwent FDG PET/CT for suspicion of PVE, and 77 patients with a PV (median age, 73 years [65-77]; 71% male; 26 mechanical valves; 45 biological; 6 transcatheter aortic valve replacements) who underwent FDG PET/CT for other indications (negative control group), were retrospectively included. Their scans were reassessed by 2 independent observers blinded to all clinical data, both visually and quantitatively on available European Association of Nuclear Medicine Research Ltd-standardized reconstructions. Confounders were identified by use of a logistic regression model and subsequently excluded.

RESULTS

Visual assessment of FDG PET/CT had a sensitivity/specificity/positive predictive value/negative predictive value for PVE of 74%/91%/89%/78%, respectively. Low inflammatory activity (C-reactive protein <40 mg/L) at the time of imaging and use of surgical adhesives during prosthetic heart valve implantation were significant confounders, whereas recent valve implantation was not. After the exclusion of patients with significant confounders, diagnostic performance values of the visual assessment increased to 91%/95%/95%/91%. As a semiquantitative measure of FDG uptake, a European Association of Nuclear Medicine Research Ltd-standardized uptake value ratio of ≥2.0 was a 100% sensitive and 91% specific predictor of PVE.

CONCLUSIONS

Both visual and quantitative assessments of FDG PET/CT have a high diagnostic accuracy in patients in whom PVE is suspected. FDG PET/CT should be implemented early in the diagnostic workup to prevent the negative confounding effects of low inflammatory activity (eg, attributable to prolonged antibiotic therapy). Recent valve implantation was not a significant predictor of false-positive interpretations, but surgical adhesives used during implantation were.

Cardiac imaging after ischemic stroke : Echocardiography, CT, or MRI?

About 20–25% of all ischemic strokes are of cardioembolic etiology, with atrial fibrillation and heart failure as the most common underlying pathologies. Diagnostic work-up by noninvasive cardiac imaging is essential since it may lead to changes in therapy, e.g., in—but not exclusively—secondary stroke prevention. Echocardiography remains the cornerstone of cardiac imaging after ischemic stroke, with the combination of transthoracic and transesophageal echocardiography as gold standard thanks to their high sensitivity for many common pathologies. Transesophageal echocardiography should be considered as the initial diagnostic tool when a cardioembolic source of stroke is suspected. However, to date, there is no proven benefit of transesophageal echocardiography-related therapy changes on the main outcomes after ischemic stroke. Based on the currently available data, cardiac computed tomography and magnetic resonance imaging should be regarded as complementary methods to echocardiography, providing additional information in specific situations; however, they cannot be recommended as first-line modalities.

Methicillin-Resistant Staphylococcus aureus Prosthetic Valve Endocarditis: Pathophysiology, Epidemiology, Clinical Presentation, Diagnosis, and Management

Staphylococcus aureus prosthetic valve endocarditis (PVE) remains among the most morbid bacterial infections, with mortality estimates ranging from 40% to 80%. The proportion of PVE cases due to methicillin-resistant Staphylococcus aureus (MRSA) has grown in recent decades, to account for more than 15% of cases of S. aureus PVE and 6% of all cases of PVE. Because no large studies or clinical trials for PVE have been published, most guidelines on the diagnosis and management of MRSA PVE rely upon expert opinion and data from animal models or related conditions (e.g., coagulase-negative Staphylococcus infection). We performed a review of the literature on MRSA PVE to summarize data on pathogenic mechanisms and updates in epidemiology and therapeutic management and to inform diagnostic strategies and priority areas where additional clinical and laboratory data will be particularly useful to guide therapy. Major updates discussed in this review include novel diagnostics, indications for surgical management, the utility of aminoglycosides in medical therapy, and a review of newer antistaphylococcal agents used for the management of MRSA PVE.

Quest for cardiovascular interventions: precise modeling and 3D printing of heart valves

Digitalization of health care practices is substantially manifesting itself as an effective tool to diagnose and rectify complex cardiovascular abnormalities. For cardiovascular abnormalities, precise non-invasive imaging interventions are being used to develop patient specific diagnosis and surgical planning. Concurrently, pre surgical 3D simulation and computational modeling are aiding in the effective surgery and understanding of valve biomechanics, respectively. Consequently, 3D printing of patient specific valves that can mimic the original one will become an effective outbreak for valvular problems. Printing of these patient-specific tissues or organ components is becoming a viable option owing to the advances in biomaterials and additive manufacturing techniques. These additive manufacturing techniques are receiving a full-fledged support from burgeoning field of computational fluid dynamics, digital image processing, artificial intelligence, and continuum mechanics during their optimization and implementation. Further, studies at cellular and molecular biomechanics have enriched our understanding of biomechanical factors resulting in valvular heart diseases. Hence, the knowledge generated can guide us during the design and synthesis of biomaterials to develop superior extra cellular matrix, mimicking materials that can be used as a bioink for 3D printing of organs and tissues. With this notion, we have reviewed current opportunities and challenges in the diagnosis and treatment of heart valve abnormalities through patient-specific valve design via tissue engineering and 3D bioprinting. These valves can replace diseased valves by preserving homogeneity and individuality of the patients.