A joint procedural position statement on imaging in cardiac sarcoidosis: from the Cardiovascular and Inflammation & Infection Committees of the European Association of Nuclear Medicine, the European Association of Cardiovascular Imaging, and the American Society of Nuclear Cardiology

Cardiac sarcoidosis: diagnosis and management

Non-caseating granulomatous infiltration of the myocardium is the hallmark of cardiac sarcoidosis (CS). CS manifests clinically as conduction disturbance, ventricular arrhythmia, sudden cardiac death and/or heart failure with reduced ejection fraction. Other than confirmation through endomyocardial biopsy, a diagnosis of probable CS can be established by histological evidence of systemic sarcoidosis in addition to characteristic clinical or advanced imaging findings. Cardiac Magnetic Resonance imaging (CMR) and 18F-flurodeoxyglycose positron emission tomography (FDG-PET) are imaging modalities indispensable in the diagnosis and monitoring of CS. FDG-PET is the method of choice for identifying the active inflammatory phase of CS and in the monitoring and modifying of immunosuppressive treatment. CMR is better suited for assessing cardiac morphology and function. Both modalities are more effective in detecting CS when used in combination than either is alone. Management of CS is primarily based upon observational data of low quality due to a paucity of randomized controlled trials. Corticosteroid therapy and/or tiered-immunosuppression are the mainstays of treatment in reducing myocardial inflammation. Steroid-sparing agents aim to limit the unfavorable side-effects of a significant steroid burden. Antiarrhythmics and guideline-directed medical therapies are utilized for control of ventricular arrhythmia and left ventricular dysfunction respectively. CS necessitates multidisciplinary care in specialized centers to most effectively diagnose and manage the disease. Additional randomized trials are warranted to further our understanding of medical optimization in CS.

Innovations in Imaging: 18F-Fluorodeoxyglucose PET/CT for Assessment of Cardiovascular Infection and Inflammation

PURPOSE OF REVIEW

18F-Fluorodeoxyglucose positron emission tomography (PET) combined with computed tomography (CT), referred to as 18F-FDG PET/CT, plays a significant role in the diagnosis and management of patients with systemic infectious and inflammatory conditions. This review provides an overview of 18F-FDG PET/CT in systemic infectious and inflammatory conditions, including infective endocarditis (IE), cardiac implantable electrical device (CIED)/left ventricular assist device (LVAD) infection, sarcoidosis, and large-vessel vasculitis (LVV).

RECENT FINDINGS

This review highlights the past and present literature in the increasing role of 18F-FDG PET/CT in cardiovascular inflammation and infection, including diagnostic and prognostic findings. They key aspects of this paper are to highlight the importance of 18F-FDG PET/CT in cardiovascular infection and inflammation, and to provide illustrations of how it can contribute to patient diagnosis and management.

Multimodality imaging in arrhythmogenic cardiomyopathy - From diagnosis to management

Arrhythmogenic Cardiomyopathy (AC), an inherited cardiac disorder characterized by myocardial fibrofatty replacement, carries a significant risk of sudden cardiac death (SCD) due to ventricular arrhythmias. A comprehensive multimodality imaging approach, including echocardiography, cardiac magnetic resonance imaging (CMR), and cardiac computed tomography (CCT), allows for accurate diagnosis, effective risk stratification, vigilant monitoring, and appropriate intervention, leading to improved patient outcomes and the prevention of SCD. Echocardiography is primary tool ventricular morphology and function assessment, CMR provides detailed visualization, CCT is essential in early stages for excluding congenital anomalies and coronary artery disease. Echocardiography is preferred for follow-up, with CMR capturing changes over time. The strategic use of these imaging methods aids in confirming AC, differentiating it from other conditions, tracking its progression, managing complications, and addressing end-stage scenarios.

Advances in the diagnosis of myocarditis in idiopathic inflammatory myopathies: an overview of diagnostic tests

Cardiac involvement in idiopathic inflammatory myopathies (IIM) purports to worse clinical outcomes, and therefore early identification is important. Research has focused on blood biomarkers and basic investigations such as ECG and echocardiography, which have the advantage of wide availability and low cost but are limited in their sensitivity and specificity. Imaging the myocardium to directly look for inflammation and scarring has therefore been explored, with a number of new methods for doing this gaining wider research interest and clinical availability. Cardiovascular magnetic resonance (CMR) with contemporary multiparametric mapping techniques and late gadolinium enhancement imaging, is an extremely valuable and increasingly used non-invasive imaging modality for the diagnosis of myocarditis. The recently updated CMR-based Lake Louise Criteria for the diagnosis of myocarditis incorporate the newer T1 and T2 mapping techniques, which have greatly improved the diagnostic accuracy for IIM myocarditis.18F-FDG-PET/CT is a well-utilized imaging modality in the diagnosis of malignancies in IIM, and it also has a role for the diagnosis of myocarditis in multiple systemic inflammatory diseases. Endomyocardial biopsy, however, remains the gold standard technique for the diagnosis of myocarditis and is necessary for the diagnosis of specific cases of myocarditis. This article provides an overview of the important tests and imaging modalities that clinicians should consider when faced with an IIM patient with potential myocarditis.

2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults

Transthoracic echocardiography (TTE) is the most widely available and utilised imaging modality for the screening, diagnosis, and serial monitoring of all abnormalities related to cardiac structure or function. The primary objectives of this document are to provide (1) a guiding framework for treating clinicians of the acceptable indications for the initial and serial TTE assessments of the commonly encountered cardiovascular conditions in adults, and (2) the minimum required standard for TTE examinations and reporting for imaging service providers. The main areas covered within this Position Statement pertain to the TTE assessment of the left and right ventricles, valvular heart diseases, pericardial diseases, aortic diseases, infective endocarditis, cardiac masses, pulmonary hypertension, and cardiovascular diseases associated with cancer treatments or cardio-oncology. Facilitating the optimal use and performance of high quality TTEs will prevent the over or under-utilisation of this resource and unnecessary downstream testing due to suboptimal or incomplete studies.

Diagnostic and management strategies in cardiac sarcoidosis

Cardiac sarcoidosis (CS) is increasingly recognized in the context of with otherwise unexplained electrical or structural heart disease due to improved diagnostic tools and awareness. Therefore, clinicians require improved understanding of this rare but fatal disease to care for these patients. The cardinal features of CS, include arrhythmias, atrio-ventricular conduction delay and cardiomyopathy. In addition to treatments tailored to these cardiac manifestations, immunosuppression plays a key role in active CS management. However, clinical trial and consensus guidelines are limited to guide the use of immunosuppression in these patients. This review aims to provide a practical overview to the current diagnostic challenges, treatment approach, and future opportunities in the field of CS.

The Role of Magnetic Resonance Imaging in Cardiomyopathies in the Light of New Guidelines: A Focus on Tissue Mapping

Cardiomyopathies (CMPs) are a group of myocardial disorders that are characterized by structural and functional abnormalities of the heart muscle. These abnormalities occur in the absence of coronary artery disease (CAD), hypertension, valvular disease, and congenital heart disease. CMPs are an increasingly important topic in the field of cardiovascular diseases due to the complexity of their diagnosis and management. In 2023, the ESC guidelines on cardiomyopathies were first published, marking significant progress in the field. The growth of techniques such as cardiac magnetic resonance imaging (CMR) and genetics has been fueled by the development of multimodal imaging approaches. For the diagnosis of CMPs, a multimodal imaging approach, including CMR, is recommended. CMR has become the standard for non-invasive analysis of cardiac morphology and myocardial function. This document provides an overview of the role of CMR in CMPs, with a focus on tissue mapping. CMR enables the characterization of myocardial tissues and the assessment of cardiac functions. CMR sequences and techniques, such as late gadolinium enhancement (LGE) and parametric mapping, provide detailed information on tissue composition, fibrosis, edema, and myocardial perfusion. These techniques offer valuable insights for early diagnosis, prognostic evaluation, and therapeutic guidance of CMPs. The use of quantitative CMR markers enables personalized treatment plans, improving overall patient outcomes. This review aims to serve as a guide for the use of these new tools in clinical practice.

Cardiac transplant rejection assessment with 18F-FDG PET-CT: initial single-centre experience for diagnosis and management

BACKGROUND

Rejection is a major cause of mortality and morbidity in heart transplant (HTx) recipients. Current methods for diagnosing rejection have limitations. Imaging methods to map the entire left ventricle and reliably identify potential sites of rejection is lacking. Animal studies suggest FDG PET-CT (FDG PET) could have potential application in human HTx recipients.

METHODS

Between December 2020 and February 2022, all HTx recipients at Harefield Hospital, London, with definite or suspected rejection underwent FDG PET in addition to routine work-up.

RESULTS

Thirty HTx recipients (12 with definite and 18 with suspected rejection) underwent FDG PET scans. Overall, 12 of the 30 patients had FDG PET with increased myocardial avidity, of whom 2 died (17%). Eighteen patients of the 30 patients had FDG PET with no myocardial avidity and all are alive (100%, p = 0.15). All patients with definite rejection, scanned within 2 weeks of starting anti-rejection treatment, showed increased myocardial avidity. In 5 cases, FDG PET showed myocardial avidity beyond 6 weeks despite pulsed steroid treatment, suggesting unresolved myocardial rejection.

CONCLUSION

Preliminary findings suggest FDG PET may have a role in diagnosing cardiac transplant rejection. Future blinded studies are needed to help further validate this.

[Therapeutic Pathways in Sarcoidosis. A Position Paper of the German Society of Respiratory Medicine (DGP)]

The present recommendations on the therapy of sarcoidosis of the German Respiratory Society (DGP) was written in 2023 as a German-language supplement and update of the international guidelines of the European Respiratory Society (ERS) from 2021. It contains 5 PICO questions (Patients, Intervention, Comparison, Outcomes) agreed in the consensus process, which are explained in the background text of the four articles: Confirmation of diagnosis and monitoring of the disease under therapy, general therapy recommendations, therapy of cutaneous sarcoidosis, therapy of cardiac sarcoidosis.

Total-Body PET/CT Applications in Cardiovascular Diseases: A Perspective Document of the SNMMI Cardiovascular Council

Digital PET/CT systems with a long axial field of view have become available and are emerging as the current state of the art. These new camera systems provide wider anatomic coverage, leading to major increases in system sensitivity. Preliminary results have demonstrated improvements in image quality and quantification, as well as substantial advantages in tracer kinetic modeling from dynamic imaging. These systems also potentially allow for low-dose examinations and major reductions in acquisition time. Thereby, they hold great promise to improve PET-based interrogation of cardiac physiology and biology. Additionally, the whole-body coverage enables simultaneous assessment of multiple organs and the large vascular structures of the body, opening new opportunities for imaging systemic mechanisms, disorders, or treatments and their interactions with the cardiovascular system as a whole. The aim of this perspective document is to debate the potential applications, challenges, opportunities, and remaining challenges of applying PET/CT with a long axial field of view to the field of cardiovascular disease.

Sarcoid heart disease and imaging

Cardiac sarcoidosis (CS) can mimic any cardiomyopathy due to its ability to manifest with a variety of clinical presentations. The exact prevalence of CS remains unknown but has been reported ranging from 2.3% to as high as 29.9% among patients presenting with new onset cardiomyopathy and/or atrioventricular block. Early and accurate diagnosis of CS is often challenging due to the nature of disease progression and lack of diagnostic reference standard. The current diagnostic criteria for CS are lacking in sensitivity and specificity. Here, we review the contemporary role of advanced imaging modalities such as cardiac magnetic resonance imaging and positron emission tomography/computed tomography imaging in diagnosing and prognosticating patients with CS.

The clinical value of quantitative cardiovascular molecular imaging: a step towards precision medicine

Cardiovascular diseases (CVD) are the leading cause of death worldwide and have an increasing impact on society. Precision medicine, in which optimal care is identified for an individual or a group of individuals rather than for the average population, might provide significant health benefits for this patient group and decrease CVD morbidity and mortality. Molecular imaging provides the opportunity to assess biological processes in individuals in addition to anatomical context provided by other imaging modalities and could prove to be essential in the implementation of precision medicine in CVD. New developments in single-photon emission computed tomography (SPECT) and positron emission tomography (PET) systems, combined with rapid innovations in promising and specific radiopharmaceuticals, provide an impressive improvement of diagnostic accuracy and therapy evaluation. This may result in improved health outcomes in CVD patients, thereby reducing societal impact. Furthermore, recent technical advances have led to new possibilities for accurate image quantification, dynamic imaging, and quantification of radiotracer kinetics. This potentially allows for better evaluation of disease activity over time and treatment response monitoring. However, the clinical implementation of these new methods has been slow. This review describes the recent advances in molecular imaging and the clinical value of quantitative PET and SPECT in various fields in cardiovascular molecular imaging, such as atherosclerosis, myocardial perfusion and ischemia, infiltrative cardiomyopathies, systemic vascular diseases, and infectious cardiovascular diseases. Moreover, the challenges that need to be overcome to achieve clinical translation are addressed, and future directions are provided.

Evaluation and Management of Cardiac Sarcoidosis with Advanced Imaging

A high clinical suspicion in the setting of appropriate history, physical exam, laboratory, and imaging parameters is often required to set the groundwork for diagnosis and management. Echocardiography may show septal thinning, evidence of systolic and diastolic dysfunction, along with impaired global longitudinal strain. Cardiac MRI reveals late gadolinium enhancement along with evidence of myocardial edema and inflammation on T2 weighted imaging and parametric mapping. 18F-FDG PET detects the presence of active inflammation and the presence of scar. Involvement of the right ventricle on MRI or PET confers a high risk for adverse cardiac events and mortality.

Combined FDG PET/MRI versus Standard-of-Care Imaging in the Evaluation of Cardiac Sarcoidosis

PURPOSE

To compare combined cardiac fluorine 18 (18F) fluorodeoxyglucose (FDG) PET/MRI with standard-of-care evaluation using cardiac MRI, 18F-FDG PET/CT, and SPECT perfusion imaging in suspected cardiac sarcoidosis (CS) with respect to radiation dose, imaging duration, and diagnostic test performance.

MATERIALS AND METHODS

Consecutive patients with suspected CS undergoing clinical evaluation with cardiac 18F-FDG PET/CT and gated rest technetium 99m sestamibi SPECT perfusion imaging were prospectively recruited between November 2017 and May 2021 for parallel assessment with combined cardiac 18F-FDG PET/MRI on the same day (ClinicalTrials.gov identifier, NCT03356756). Total effective radiation dose and imaging duration were compared between approaches (combined cardiac PET/MRI vs separate cardiac MRI, PET/CT, and SPECT). MRI findings were initially interpreted without PET data, and then PET and late gadolinium enhancement images were fused and interpreted together. Final diagnosis of CS was established using Japanese Ministry of Health and Welfare guidelines.

RESULTS

Forty participants (mean age, 54 years ± 14 [SD]; 26 [65%] male participants) were included, 14 (35%) with a final diagnosis of CS. Compared with separate cardiac MRI, PET/CT, and SPECT perfusion imaging, combined cardiac PET/MRI had 52% lower total radiation dose (8.0 mSv ± 1.2 vs 16.8 mSv ± 1.6, P < .001) and 43% lower total imaging duration (122 minutes ± 15 vs 214 minutes ± 26, P < .001). Combined PET/MRI had the highest area under the curve for diagnosis of CS (0.84) with 96% specificity and 71% sensitivity for colocalized FDG uptake and late gadolinium enhancement in a pattern typical for CS.

CONCLUSION

In the evaluation of suspected CS, combined cardiac 18F-FDG PET/MRI had a lower radiation dose, shorter imaging duration, and higher diagnostic performance compared with standard-of-care imaging.Clinical trial registration no. NCT03356756Keywords: Cardiac Sarcoidosis, 18F-FDG PET/MRI, 18F-FDG PET/CT, SPECT Perfusion Imaging, Cardiac MRI, Standard-of-Care Imaging Supplemental material is available for this article. © RSNA, 2023.

The Role of Echocardiography in the Contemporary Diagnosis and Prognosis of Cardiac Sarcoidosis: A Comprehensive Review

Cardiac sarcoidosis (CS) is a rare inflammatory disorder characterised by the presence of non-caseating granulomas within the myocardium. Contemporary studies have revealed that 25-30% of patients with systemic sarcoidosis have cardiac involvement, with detection rates increasing in the era of advanced cardiac imaging. The use of late gadolinium enhancement cardiac magnetic resonance and 18fluorodeoxy glucose positron emission tomography (FDG-PET) imaging has superseded endomyocardial biopsy for the diagnosis of CS. Echocardiography has historically been used as a screening tool with abnormalities triggering the need for advanced imaging, and as a tool to assess cardiac function. Regional wall thinning or aneurysm formation in a noncoronary distribution may indicate granuloma infiltration. Thinning of the basal septum in the setting of extracardiac sarcoidosis carries a high specificity for cardiac involvement. Abnormal myocardial echotexture and eccentric hypertrophy may be suggestive of active myocardial inflammation. The presence of right-ventricular involvement as indicated by free-wall aneurysms can mimic arrhythmogenic right-ventricular cardiomyopathy. More recently, the use of myocardial strain has increased the sensitivity of echocardiography in diagnosing cardiac involvement. Echocardiography is limited in prognostication, with impaired left-ventricular (LV) ejection fraction and LV dilatation being the only established independent predictors of mortality. More research is required to explore how advanced echocardiographic technologies can increase both the diagnostic sensitivity and prognostic ability of this modality in CS.

Diagnosis of cardiac sarcoidosis: histological evidence vs. imaging

INTRODUCTION

The prognosis for cardiac sarcoidosis (CS) remains unfavorable. Although early and accurate diagnosis is crucial, the low detection rate of endomyocardial biopsy makes accurate diagnosis challenging.

AREAS COVERED

The Heart Rhythm Society (HRS) consensus statement and the Japanese Circulation Society (JCS) guidelines are two major diagnostic criteria for the diagnosis of CS. While the requirement of positive histology for the diagnosis in the HRS criteria can result in overlooked cases, the JCS guidelines advocate for a group of 'clinical' diagnoses based on advanced imaging, including cardiovascular magnetic resonance and 18F-fluorodeoxyglucose positron emission tomography, which do not require histological evidence. Recent studies have supported the usefulness of clinical diagnosis of CS. However, other evidence suggests that clinical CS may sometimes be inaccurate. This article describes the advantages and disadvantages of the current diagnostic criteria for CS, and typical imaging and clinical courses.

EXPERT OPINION

The diagnosis of clinical CS has been made possible by recent developments in multimodality imaging. However, it is still crucial to look for histological signs of sarcoidosis in other organs in addition to the endomyocardium. Additionally, phenotyping based on clinical manifestations such as heart failure, conduction abnormality or ventricular arrhythmia, and extracardiac abnormalities is clinically significant.

Positron Emission Tomography in Heart Failure: From Pathophysiology to Clinical Application

Imaging modalities are increasingly being used to evaluate the underlying pathophysiology of heart failure. Positron emission tomography (PET) is a non-invasive imaging technique that uses radioactive tracers to visualize and measure biological processes in vivo. PET imaging of the heart uses different radiopharmaceuticals to provide information on myocardial metabolism, perfusion, inflammation, fibrosis, and sympathetic nervous system activity, which are all important contributors to the development and progression of heart failure. This narrative review provides an overview of the use of PET imaging in heart failure, highlighting the different PET tracers and modalities, and discussing fields of present and future clinical application.

Hot spot imaging in cardiovascular diseases: an information statement from SNMMI, ASNC, and EANM

This information statement from the Society of Nuclear Medicine and Molecular Imaging, American Society of Nuclear Cardiology, and European Association of Nuclear Medicine describes the performance, interpretation, and reporting of hot spot imaging in nuclear cardiology. The field of nuclear cardiology has historically focused on cold spot imaging for the interpretation of myocardial ischemia and infarction. Hot spot imaging has been an important part of nuclear medicine, particularly for oncology or infection indications, and the use of hot spot imaging in nuclear cardiology continues to expand. This document focuses on image acquisition and processing, methods of quantification, indications, protocols, and reporting of hot spot imaging. Indications discussed include myocardial viability, myocardial inflammation, device or valve infection, large vessel vasculitis, valve calcification and vulnerable plaques, and cardiac amyloidosis. This document contextualizes the foundations of image quantification and highlights reporting in each indication for the cardiac nuclear imager.

Cardiovascular positron emission tomography: established and emerging role in cardiovascular diseases

Cardiac positron emission tomography (PET) imaging has established themselves firmly as excellent and reliable functional imaging modalities in assessment of the spectrum of coronary artery disease. With the explosion of technology advances and the dream of flow quantification now a reality, the value of PET is now well realized. Cardiac PET has proved itself as precise imaging modality that provides functional imaging of the heart in addition to anatomical imaging. It has established itself as one of the best available techniques for evaluation of myocardial viability. Hybrid PET/computed tomography provides simultaneous integration of coronary anatomy and function with myocardial perfusion and metabolism, thereby improving characterization of the dysfunctional area and chronic coronary artery disease. The availability of quantitative myocardial blood flow evaluation with PET provides additional prognostic information and increases diagnostic accuracy in the management of patients with coronary artery disease. Hybrid imaging seems to hold immense potential in optimizing management of cardiovascular diseases and furthering clinical research.

Nuclear medicine in the assessment and prevention of cancer therapy-related cardiotoxicity: prospects and proposal of use by the European Association of Nuclear Medicine (EANM)

Cardiotoxicity may present as (pulmonary) hypertension, acute and chronic coronary syndromes, venous thromboembolism, cardiomyopathies/heart failure, arrhythmia, valvular heart disease, peripheral arterial disease, and myocarditis. Many of these disease entities can be diagnosed by established cardiovascular diagnostic pathways. Nuclear medicine, however, has proven promising in the diagnosis of cardiomyopathies/heart failure, and peri- and myocarditis as well as arterial inflammation. This article first outlines the spectrum of cardiotoxic cancer therapies and the potential side effects. This will be complemented by the definition of cardiotoxicity using non-nuclear cardiovascular imaging (echocardiography, CMR) and biomarkers. Available nuclear imaging techniques are then presented and specific suggestions are made for their application and potential role in the diagnosis of cardiotoxicity.

Assessment of Cardiac Sarcoidosis: FDG PET and BMIPP SPECT

PURPOSE OF REVIEW

Cardiac sarcoidosis (CS) is an inflammatory disease of unknown etiology that can lead to life-threatening arrhythmias, heart failure, and death. Advanced cardiac imaging modalities have improved the clinician's ability to detect this disease. The purpose of this review is to discuss the recent evidence of cardiac metabolic imaging as assessed by [¹⁸F]FDG PET and [¹²³I]BMIPP SPECT in the evaluation of CS patients.

RECENT FINDINGS

[¹⁸F]FDG PET is the gold standard to identify myocardial inflammation. [¹²³I]BMIPP SPECT can uncover early myocardial damage as well as advanced stages of CS when fibrosis prevails. In presence of inflammation, myocardial [¹⁸F]FDG uptake is increased, but in contrast, BMIPP myocardial uptake is reduced or even suppressed. Thus, a complementary role of cardiac metabolic imaging by [¹⁸F]FDG PET and BMIPP SPECT has been proposed to detect the whole spectrum of CS. [¹⁸F]FDG PET is considered an important tool to improve the diagnosis and optimize the management of CS. The role of [¹²³I]BMIPP SPECT in diagnosing CS is still under investigation. Further studies are needed to evaluate the clinical utility of combined cardiac metabolic imaging in the diagnosis, prognosis, and for selecting treatments in CS patients.

Real-time three-dimensional echocardiography for detection of cardiac sarcoidosis in the early stage: a cross-sectional single-centre study

BACKGROUND

Sarcoidosis with cardiac involvement has a relatively high morbidity and mortality, and early diagnose of cardiac sarcoidosis is a critical issue. Systolic dyssynchrony index (SDI) measured by three-dimensional echocardiography was used in our study for detection of subclinical left ventricular (LV) systolic dysfunction in patients with sarcoidosis and normal LV function on two-dimensional echocardiography.

METHODS

Forty-four patients diagnosed with sarcoidosis (without clinically apparent cardiac involvement) and 44 healthy control subjects were included in this study. Two-dimensional echocardiographic parameters, also LV volumes and SDI measured by 3D echocardiography were analyzed in all participants.

RESULTS

While two-dimensional echocardiographic results of both study groups were similar; SDI_16 (SDI for 16 segments of LV) results were significantly higher in sarcoidosis group compared to healthy controls (6.99 ±5.02 vs 2.89 ± 1.32, p < 0.0001).

CONCLUSION

SDI_16 was higher in patients with sarcoidosis compared to healthy controls probably due to patchy infiltration characteristic of the disease. This parameter could be used as a marker to identify patients with cardiac involvement of sarcoidosis in the early phase.

Potential novel imaging targets of inflammation in cardiac sarcoidosis

Cardiac sarcoidosis (CS) is an inflammatory disease with high morbidity and mortality, with a pathognomonic feature of non-caseating granulomatous inflammation. While 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is a well-established modality to image inflammation and diagnose CS, there are limitations to its specificity and reproducibility. Imaging focused on the molecular processes of inflammation including the receptors and cellular microenvironments present in sarcoid granulomas provides opportunities to improve upon FDG-PET imaging for CS. This review will highlight the current limitations of FDG-PET imaging for CS while discussing emerging new nuclear imaging molecular targets for the imaging of cardiac sarcoidosis.

Contemporary approach to catheter ablation of ventricular tachycardia in nonischemic cardiomyopathy

Nonischemic cardiomyopathy (NICM) comprises a heterogenous group of disorders with myocardial dysfunction unrelated to significant coronary disease. As the use of implantable defibrillators has increased in this patient population, catheter ablation is being utilized more frequently to treat NICM patients with ventricular tachycardia (VT). Progress has been made in identifying multiple subtypes of NICM with variable scar patterns. The distribution of scar is often mid-myocardial and subepicardial, and identifying and ablating this substrate can be challenging. Here, we will review the current understanding of NICM subtypes and the outcomes of VT ablation in this population. We will discuss the use of cardiac imaging, electrocardiography, and electroanatomic mapping to define the VT substrate and the ablation techniques required to successfully prevent VT recurrence.

A role for artificial intelligence in molecular imaging of infection and inflammation

The detection of occult infections and low-grade inflammation in clinical practice remains challenging and much depending on readers’ expertise. Although molecular imaging, like [¹⁸F]FDG PET or radiolabeled leukocyte scintigraphy, offers quantitative and reproducible whole body data on inflammatory responses its interpretation is limited to visual analysis. This often leads to delayed diagnosis and treatment, as well as untapped areas of potential application. Artificial intelligence (AI) offers innovative approaches to mine the wealth of imaging data and has led to disruptive breakthroughs in other medical domains already. Here, we discuss how AI-based tools can improve the detection sensitivity of molecular imaging in infection and inflammation but also how AI might push the data analysis beyond current application toward predicting outcome and long-term risk assessment.

FDG PET/MRI of Acute Myocarditis After mRNA COVID-19 Vaccination

ABSTRACT

A 22-year-old man visited the emergency department with chest pain. He had received a second dose of the coronavirus disease 2019 (COVID-19) mRNA (Moderna) vaccine 5 days prior. 18F-FDG PET/MR revealed a focal FDG uptake and late gadolinium enhancement on the basal posterolateral wall of the left ventricle. Myocarditis after a COVID-19 vaccination has been reported predominantly after the second dose of mRNA vaccines in young men. This was a case of acute focal myocarditis after a COVID-19 mRNA vaccination, which was well-visualized by FDG PET/MRI.

Long-term, real world experience of ventricular tachycardia and granulomatous cardiomyopathy

BACKGROUND

Granulomatous cardiomyopathy(GCM) is relatively uncommon in patients presenting with ventricular tachycardia(VT). Sarcoidosis and tuberculosis are the most common causes of GCM with VT. The aim of study was to evaluate their clinical characteristics and the long-term outcomes.

METHODS

We retrospectively analyzed patients from March 2004 to January 2020, presenting with VT and subsequently diagnosed to have GCM. Patients were divided into three groups (sarcoid, tuberculosis and indeterminate) based on serologic tests, imaging and histopathology. The response to anti-arrhythmic and disease specific therapy on long-term follow-up were analysed.

RESULTS

There were 52 patients, comprising 27 males and 25 females, age 40 ± 10 years. The follow-up period was 5.9 ± 3.9 years. Sarcoidosis was diagnosed in 20(38%); tuberculosis(TB) in 15(29%) and 17(33%) patients were indeterminate. Left ventricular ejection fraction(LVEF) of the entire cohort was 0.45 ± 0.14. Erythrocyte Sedimentation Rate(ESR) was found to be significantly higher in TB(43.6 ± 18.4) patients vs sarcoid(18.9 ± 6.7)p < 0.0001, but not the indeterminate group(36.2 ± 21.1), p = 0.3. Implantable Cardioverter Defibrillator(ICD) implantation was performed in 12/20(60%) patients in the sarcoid group, in 4/15(27%) patients in the TB group and in 10/17(59%) patients in the indeterminate group. At a mean follow-up of six years, VT recurrences were noted in 6, 2, and 7 patients in the sarcoid, TB and indeterminate groups respectively.

CONCLUSION

Despite the advances in diagnostic modalities for tuberculosis and sarcoidosis, in real-world practice, almost one-third of the patients with VT and GCM have uncertain etiology. Long term outcomes of patients presenting with GCM and VT with mild left ventricle dysfunction treated appropriately seems favorable.

Nuclear Cardiology in Women and Underrepresented Minority Populations

PURPOSE OF REVIEW

To outline sex-specific features of coronary artery disease (CAD) that should be considered in the assessment of women, including those from ethnic minority populations with suspected stable ischemic heart disease (IHD). Second, to determine the latest nuclear imaging tools available to assess microvascular CAD.

RECENT FINDINGS

Latest studies indicate that women are more likely to have ischemia with no obstructive coronary arteries (INOCA) and paradoxically have worse outcomes. Therefore, the evaluation of women with suspected IHD should include assessing microvascular and epicardial coronary circulation. The prevalence of CAD is increasing in younger women due to the increased cardiovascular disease (CVD) risk burden. CAD is often underrecognized in these patients. There is increasing recognition that INOCA is not benign and should be accurately diagnosed and managed. Nuclear imaging assesses the full spectrum of CAD from microvascular CAD to multivessel obstructive epicardial CAD. Further research on myocardial blood flow (MBF) assessment with PET MPI is needed.

Current State and Future Directions of Multimodality Imaging in Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is an increasingly recognized cause of heart failure and arrhythmia. Historically challenging to identify, particularly in the absence of extracardiac sarcoidosis, diagnosis of CS has improved with advancements in cardiac imaging. Recognition as well as management may require interpretation of multiple imaging modalities. Echocardiography may serve as an initial screening study for cardiac involvement in patients with systemic sarcoidosis. Cardiac magnetic resonance imaging (CMR) provides information on diagnosis as well as risk stratification, particularly for ventricular arrhythmia in the setting of late gadolinium enhancement. More recently, ¹⁸F-fluorodeoxyglucose position emission tomography (FDG-PET) has assumed a valuable role in the diagnosis and longitudinal management of patients with CS, allowing for the assessment of response to treatment. Hybrid FDG-PET/CT may also be used in the evaluation of extracardiac inflammation, permitting the identification of biopsy sites for diagnostic confirmation. Herein we examine the approach to diagnosis and management of CS using multimodality imaging via a case-based review.

[18F]FDG-PET in cardiac sarcoidosis: A single-centre study in a southern European population

BACKGROUND

Cardiac sarcoidosis (CS) is clinically diagnosed in 5% of patients with sarcoidosis but imaging studies suggest higher prevalence. We evaluated the prevalence, clinical manifestations, and cardiovascular outcomes of CS, diagnosed through ¹⁸F-Fluorodeoxyglucose positron emission tomography ([¹⁸F]FDG-PET), in a southern European population.

METHODS

Retrospective single-centre study of patients screened for sarcoidosis with [¹⁸F]FDG-PET. Subjects with histological confirmation were divided in two groups, CS or extracardiac sarcoidosis, according to Heart Rhythm Society's criteria. Primary endpoint was defined as the composite of heart failure hospitalizations, uncontrolled arrythmias, pacemaker implantation, and cardiovascular (CV) mortality. Secondary outcomes included each component and all-cause mortality.

RESULTS

From 128 patients with biopsy-proven extracardiac sarcoidosis, 10.2% had probable CS, 54% without symptoms of cardiac involvement. Ten patients had suggestive [¹⁸F]FDG uptake patterns, three subjects had an indicative cardiac magnetic resonance (CMR). Patients with probable CS had significantly higher prevalence of coronary and valvular disease, heart failure, and atrial fibrillation compared with those without cardiac involvement. During a mean follow-up of 4.0 SD2.7 years, the primary outcome occurred more frequently in patients with probable CS (53.8% vs. 3.5%; HR 25.45; 95% CI 5.27-122.9; p < 0.01) as well as heart failure hospitalizations (46.2% vs. 0.9%), uncontrolled arrhythmias (23.1% vs. 1.7%) and pacemaker implantation (23.1% vs. 0.9%) (p < 0.01 for all). All-cause mortality was three-fold higher in probable CS, despite the absence of statistical significance (15% vs. 5%, p = 0.15).

CONCLUSIONS

Among patients with biopsy-proven sarcoidosis, cardiac involvement detected by [¹⁸F]FDG-PET or CMR is associated with a higher risk of CV events, irrespective of symptoms.

Hybrid Cardiac Magnetic Resonance/Fluorodeoxyglucose Positron Emission Tomography to Differentiate Active From Chronic Cardiac Sarcoidosis

OBJECTIVES

The purpose of this study was to investigate the diagnostic value of simultaneous hybrid cardiac magnetic resonance (CMR) and ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) for detection and differentiation of active (aCS) from chronic (cCS) cardiac sarcoidosis.

BACKGROUND

Late gadolinium enhancement (LGE) CMR and FDG-PET are both established imaging techniques for the detection of CS. However, there are limited data regarding the value of a comprehensive simultaneous hybrid CMR/FDG-PET imaging approach that includes CMR mapping techniques.

METHODS

Forty-three patients with biopsy-proven extracardiac sarcoidosis (median age: 48 years, interquartile range: 37-57 years, 65% male) were prospectively enrolled for evaluation of suspected CS. After dietary preparation for suppression of myocardial glucose metabolism, patients were evaluated on a 3-T hybrid PET/MR scanner. The CMR protocol included T1 and T2 mapping, myocardial function, and LGE imaging. We assumed aCS if PET and CMR (ie, LGE or T1/T2 mapping) were both positive (PET+/CMR+), cCS if PET was negative but CMR was positive (PET-/CMR+), and no CS if patients were CMR negative regardless of PET findings.

RESULTS

Among the 43 patients, myocardial glucose uptake was suppressed successfully in 36 (84%). Hybrid CMR/FDG-PET revealed aCS in 13 patients (36%), cCS in 5 (14%), and no CS in 18 (50%). LGE was present in 14 patients (39%); T1 mapping was abnormal in 10 (27%) and T2 mapping abnormal in 2 (6%). CS was diagnosed based on abnormal T1 mapping in 4 out of 18 CS patients (22%) who were LGE negative. PET FDG uptake was present in 17 (47%) patients.

CONCLUSIONS

Comprehensive simultaneous hybrid CMR/FDG-PET imaging is useful for the detection of CS and provides additional value for identifying active disease. Our results may have implications for enhanced diagnosis as well as improved identification of patients with aCS in whom anti-inflammatory therapy may be most beneficial.

Cytokine Signaling and Matrix Remodeling Pathways Associated with Cardiac Sarcoidosis Disease Activity Defined Using FDG PET Imaging

While cardiac imaging has improved the diagnosis and risk assessment for cardiac sarcoidosis (CS), treatment regimens have consisted of generalized heart failure therapies and non-specific anti-inflammatory regimens. The overall goal of this study was to perform high-sensitivity plasma profiling of specific inflammatory pathways in patients with sarcoidosis and with CS.Specific inflammatory/proteolytic cascades were upregulated in sarcoidosis patients, and certain profiles emerged for CS patients.Plasma samples were collected from patients with biopsy-confirmed sarcoidosis undergoing F-18 fluorodeoxyglucose positron emission tomography (n = 47) and compared to those of referent control subjects (n = 6). Using a high-sensitivity, automated multiplex array, cytokines, soluble cytokine receptor profiles (an index of cytokine activation), as well as matrix metalloproteinase (MMP), and endogenous MMP inhibitors (TIMPs) were examined.The plasma tumor necrosis factor (TNF) and soluble TNF receptors sCD30 and sTNFRI were increased using sarcoidosis, and sTNFRII increased in CS patients (n = 18). The soluble interleukin sIL-2R and vascular endothelial growth factor receptors (sVEGFR2 and sVEGFR3) increased to the greatest degree in CS patients. When computed as a function of referent control values, the majority of soluble cytokine receptors increased in both sarcoidosis and CS groups. Plasma MMP-9 levels increased in sarcoidosis but not in the CS subset. Plasma TIMP levels declined in both groups.The findings from this study were the identification of increased activation of a cluster of soluble cytokine receptors, which augment not only inflammatory cell maturation but also transmigration in patients with sarcoidosis and patients with cardiac involvement.

Sex Differences in Patients With Suspected Cardiac Sarcoidosis Assessed by Cardiovascular Magnetic Resonance Imaging

[Figure: see text].

Procedural recommendations of cardiac PET/CT imaging: standardization in inflammatory-, infective-, infiltrative-, and innervation- (4Is) related cardiovascular diseases: a joint collaboration of the EACVI and the EANM: summary

With this summarized document we share the standard for positron emission tomography (PET)/(diagnostic)computed tomography (CT) imaging procedures in cardiovascular diseases that are inflammatory, infective, infiltrative, or associated with dysfunctional innervation (4Is) as recently published in the European Journal of Nuclear Medicine and Molecular Imaging. This standard should be applied in clinical practice and integrated in clinical (multicentre) trials for optimal standardization of the procedurals and interpretations. A major focus is put on procedures using [¹⁸F]-2-fluoro-2-deoxyglucose ([¹⁸F]FDG), but 4Is PET radiopharmaceuticals beyond [¹⁸F]FDG are also described in this summarized document. Whilst these novel tracers are currently mainly applied in early clinical trials, some multicentre trials are underway and we foresee in the near future their use in clinical care and inclusion in the clinical guidelines. Diagnosis and management of 4Is related cardiovascular diseases are generally complex and often require a multidisciplinary approach by a team of experts. The new standards described herein should be applied when using PET/CT and PET/magnetic resonance, within a multimodality imaging framework both in clinical practice and in clinical trials for 4Is cardiovascular indications.

ERS clinical practice guidelines on treatment of sarcoidosis

BACKGROUND

The major reasons to treat sarcoidosis are to lower the morbidity and mortality risk or to improve quality of life (QoL). The indication for treatment varies depending on which manifestation is the cause of symptoms: lungs, heart, brain, skin, or other manifestations. While glucocorticoids (GC) remain the first choice for initial treatment of symptomatic disease, prolonged use is associated with significant toxicity. GC-sparing alternatives are available. The presented treatment guideline aims to provide guidance to physicians treating the very heterogenous sarcoidosis manifestations.

MATERIALS AND METHODS

A European Respiratory Society Task Force (TF) committee composed of clinicians, methodologists, and patients with experience in sarcoidosis developed recommendations based on the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) methodology. The committee developed eight PICO (Patients, Intervention, Comparison, Outcomes) questions and these were used to make specific evidence-based recommendations.

RESULTS

The TF committee delivered twelve recommendations for seven PICOs. These included treatment of pulmonary, cutaneous, cardiac, and neurologic disease as well as fatigue. One PICO question regarding small fiber neuropathy had insufficient evidence to support a recommendation. In addition to the recommendations, the committee provided information on how they use alternative treatments, when there was insufficient evidence to support a recommendation.

CONCLUSIONS

There are many treatments available to treat sarcoidosis. Given the diverse nature of the disease, treatment decisions require an assessment of organ involvement, risk for significant morbidity, and impact on QoL of the disease and treatment.

MESSAGE

An evidence based guideline for treatment of sarcoidosis is presented. The panel used the GRADE approach and specific recommendations are made. A major factor in treating patients is the risk of loss of organ function or impairment of quality of life.

Hidden under the Surface: A Rare Cause of Repeated Syncope in a Patient with Recent Pacemaker Implantation

A 66-year-old woman received a pacemaker implantation because of syncope with documented sinus arrest and junctional bradycardia. Three weeks later the pacemaker analysis revealed episodes of nonsustained ventricular tachycardia. Coronary angiography and invasive coronary assessment showed diffuse moderate stenosis but no significant ischemia. Three months later she experienced a new syncope and the pacemaker analysis showed runs of nonsustained ventricular tachycardia at the time of syncope. The combination of brady- and tachyarrhythmias raised concern for cardiac sarcoidosis. 18F-fluorodeoxyglucose positron emission tomography (PET) scan showed increased FDG uptake in the basal segments compatible with inflammatory disease. Cardiac magnetic resonance imaging showed late gadolinium enhancement in the same region of the PET-avid lesions. Diagnostic electrophysiologic study could induce VT. The diagnosis of cardiac sarcoidosis was made, for which high dose corticosteroids were prescribed and an upgrade to a dual chamber implantable cardioverter defibrillator was performed. Because of the localization of the lesions, an endomyocardial biopsy was not performed. All the lesions regressed completely on PET-scan after treatment with high dose corticosteroids.

Increasing Use of Cardiac PET/CT for Inflammatory and Infiltrative Heart Diseases in Korea

Recently the incidence of inflammatory and infiltrative heart diseases is increasing in Korea. Cardiac PET/CT is a useful technology evaluating inflammatory and infiltrative heart diseases. This study analyzed trends in the use of cardiac PET/CT for evaluating inflammatory and infiltrative heart diseases in the Chonnam National University Hospital and Chonnam National University Hwasun Hospital. The general trend in Korea was also assessed based on the domestic nuclear medicine database. There was a common increasing trend in the number of F-18 FDG PET/CT for the evaluation of inflammatory and infiltrative heart diseases. A representative case with cardiac sarcoidosis is illustrated.

Application-specific nuclear medicalin vivoimaging devices

Nuclear medical imaging devices, such as those enabling photon emission imaging (gamma camera, single photon emission computed tomography, or positron emission imaging), that are typically used in today's clinics are optimized for assessing large portions of the human body, and are classified as whole-body imaging systems. These systems have known limitations for organ imaging, therefore application-specific devices have been designed, constructed and evaluated. These devices, given their compact nature and superior technical characteristics, such as their higher detection sensitivity and spatial resolution for organ imaging compared to whole-body imaging systems, have shown promise for niche applications. Several of these devices have further been integrated with complementary anatomical imaging devices. The objectives of this review article are to (1) provide an overview of such application-specific nuclear imaging devices that were developed over the past two decades (in the twenty-first century), with emphasis on brain, cardiac, breast, and prostate imaging; and (2) discuss the rationale, advantages and challenges associated with the translation of these devices for routine clinical imaging. Finally, a perspective on the future prospects for application-specific devices is provided, which is that sustained effort is required both to overcome design limitations which impact their utility (where these exist) and to collect the data required to define their clinical value.

Clinical Features and Diagnosis of Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is an unusual, but potentially harmful, manifestation of systemic sarcoidosis (SA), a chronic disease characterized by organ involvement from noncaseating and nonnecrotizing granulomas. Lungs and intrathoracic lymph nodes are usually the sites that are most frequently affected, but no organ is spared and CS can affect a variable portion of SA patients, up to 25% from post-mortem studies. The cardiovascular involvement is usually associated with a bad prognosis and is responsible for the major cause of death and complications, particularly in African American patients. Furthermore, the diagnosis is often complicated by the occurrence of non-specific clinical manifestations, which can mimic the effect of more common heart disorders, and imaging and biopsies are the most valid approach to avoid misdiagnosis. This narrative review summarizes the main clinical features of CS and imaging findings, particularly of CMR and 18-Fluorodeoxyglucose Positron Emission Tomography (18F-FDG PET) that can give the best cost/benefit ratio in terms of the diagnostic approach. Imaging can be very useful in replacing the endomyocardial biopsy in selected cases, to avoid unnecessary, and potentially dangerous, invasive maneuvers.