Serial FDG-PET scans help to identify steroid resistance in cardiac sarcoidosis

Management of cardiac sarcoidosis

Cardiac sarcoidosis (CS) is a form of inflammatory cardiomyopathy associated with significant clinical complications such as high-degree atrioventricular block, ventricular tachycardia, and heart failure as well as sudden cardiac death. It is therefore important to provide an expert consensus statement summarizing the role of different available diagnostic tools and emphasizing the importance of a multidisciplinary approach. By integrating clinical information and the results of diagnostic tests, an accurate, validated, and timely diagnosis can be made, while alternative diagnoses can be reasonably excluded. This clinical expert consensus statement reviews the evidence on the management of different CS manifestations and provides advice to practicing clinicians in the field on the role of immunosuppression and the treatment of cardiac complications based on limited published data and the experience of international CS experts. The monitoring and risk stratification of patients with CS is also covered, while controversies and future research needs are explored.

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.

Myocardial Oedema as a Consequence of Viral Infection and Persistence-A Narrative Review with Focus on COVID-19 and Post COVID Sequelae

Microvascular integrity is a critical factor in myocardial fluid homeostasis. The subtle equilibrium between capillary filtration and lymphatic fluid removal is disturbed during pathological processes leading to inflammation, but also in hypoxia or due to alterations in vascular perfusion and coagulability. The degradation of the glycocalyx as the main component of the endothelial filtration barrier as well as pericyte disintegration results in the accumulation of interstitial and intracellular water. Moreover, lymphatic dysfunction evokes an increase in metabolic waste products, cytokines and inflammatory cells in the interstitial space contributing to myocardial oedema formation. This leads to myocardial stiffness and impaired contractility, eventually resulting in cardiomyocyte apoptosis, myocardial remodelling and fibrosis. The following article reviews pathophysiological inflammatory processes leading to myocardial oedema including myocarditis, ischaemia-reperfusion injury and viral infections with a special focus on the pathomechanisms evoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In addition, clinical implications including potential long-term effects due to viral persistence (long COVID), as well as treatment options, are discussed.

Association of longitudinal cardiac troponin trajectory with adverse events in patients with cardiac sarcoidosis

BACKGROUND

Although high-sensitivity cardiac troponins may be sensitive and easily repeatable markers of disease activity in patients with cardiac sarcoidosis (CS), the association between longitudinal cardiac troponin trajectory and adverse events remains unclear. This study aimed to clarify whether longitudinal cardiac troponin levels were associated with adverse events in patients with CS.

METHODS

We examined 63 consecutive CS-initiated prednisolone (PSL) patients with available longitudinal high-sensitivity cardiac troponin T (cTnT) data between December 2013 and March 2023. The area under the cTnT trajectory, which reflected cumulative cTnT release, was calculated to assess the association between longitudinal cTnT levels and adverse events. Patients were divided into two groups according to the median area under the cTnT trajectory per month. The primary outcome was a composite of sustained ventricular tachycardia or fibrillation, worsening heart failure, and sudden cardiac death (SCD).

RESULTS

In total, 463 cTnT measurements were collected over a median follow-up period of 30.4 (interquartile range [IQR] 15.6-34.2) months. The primary outcome was observed in 12 (19%) patients. A higher area under the cTnT trajectory was significantly associated with an increased incidence of the primary outcome (P = 0.027), while cTnT levels before and one month after initiation of PSL, and these changes were not related to adverse events (P = 0.179, 0.096, and 0.95, respectively).

CONCLUSIONS

Longitudinal cTnT trajectory following PSL initiation was associated with adverse cardiac events in patients with CS, suggesting that longitudinal measurement of cTnT would be useful for the early identification of high-risk patients.

FDG PET/CT Imaging of Sarcoidosis

Sarcoidosis is a multisystemic granulomatous disease of unknown etiology. The diagnostic can be made by histological identification of non-caseous granuloma or by a combination of clinical criteria. Active inflammatory granuloma can lead to fibrotic damage. Although 50% of cases resolve spontaneously, systemic treatments are often necessary to decrease symptoms and avoid permanent organ dysfunction, notably in cardiac sarcoidosis. The course of the disease can be punctuated by exacerbations and relapses and the prognostic depends mainly on affected sites and patient management. FDG-PET/CT along with newer FDG-PET/MR have emerged as key imaging modalities in sarcoidosis, namely for certain diagnostic purposes, staging and biopsy guiding. By identifying with a high sensitivity inflammatory active granuloma, FDG hybrid imaging is a main prognostic tool and therapeutic ally in sarcoidosis. This review aims to highlight the actual critical roles of hybrid PET imaging in sarcoidosis and display a brief perspective for the future which appears to include other radiotracers and artificial intelligence applications.

Investigating the treatment phenotypes of cardiac sarcoidosis: A prospective cohort study

Introduction

Data indicates there are 4 main pulmonary sarcoidosis duration/treatment phenotypes: asymptomatic, acute (disease duration <1-2 years), chronic and advanced. There are no data about disease duration/treatment phenotypes of cardiac sarcoidosis patients. Our study had 2 main aims (i) to assess the response to corticosteroids and (ii) to assess the incidence of relapse after a one-year course of corticosteroids (thereby classifying patients as acute or chronic treatment phenotype).

Methods

Consecutive, treatment naive patients with CS were prospectively recruited and treated with 0.5 mg/kg prednisone, to a maximum dose of 40 mg/day. Patients had a follow-up PET after 3-6 months of therapy (PET 2). In the responders (PET definition of response) the prednisone was then weaned and stopped after 12 months. Three months after stopping, the PET was repeated to look for disease relapse (PET 3).

Results

Twenty-one consecutive patients were included, and all patients showed a reduction in cardiac FDG uptake after 3-6 months and 19/21 (90.5 %) met the PET definition of response. Of these, 12/19 (63.1 %) relapsed after prednisone was stopped. There were no serious adverse effects during the trial of therapy cessation and there were no later relapses in the 7 non-relapsers during over 4 years of subsequent follow-up.

Conclusion

The initial response rate to prednisone was high with all patients showing a reduction in FDG uptake and 19/21 meeting a PET definition of >25 % response. Secondly, a trial of therapy discontinuation was able to classify 7/19 patients as acute treatment phenotype and 12/19 as chronic.

Ventricular Tachycardia in Granulomatous Myocarditis: Role of Catheter Ablation

Granulomatous myocarditis is an inflammatory disease of the myocardium, characterized by lymphocytic infiltration with characteristic granuloma formation. Although a host of disease processes can elicit myocardial granulomas, two common entities are cardiac sarcoidosis and cardiac tuberculosis. Cardiac arrhythmias in this condition are frequent and management of ventricular arrhythmias can be challenging, especially in those with drug-refractory ventricular tachycardia and electrical storm. In this review, we highlight the role of catheter ablation for ventricular tachycardia and optimal patient selection for catheter ablation, based on cardiac imaging.

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.

The Continuing Relationship Between ASNC and JSNC: Joint Symposium in JSNC 2022

The Japanese Society of Nuclear Cardiology (JSNC) and the American Society of Nuclear Cardiology (ASNC) have a relationship through a memorandum of understanding (MOU). This April, the MOU was extended for two more years. Based on this MOU, we hold a joint symposium at the JSNC annual meeting early in the summer each year. The theme of the joint symposium this year was "Inflammatory diseases of heart and large vessels". We consider the success of the joint symposium to be the fruit of the close relationship between JSNC and ASNC.

Successful treatment of recurrent cardiac sarcoidosis with the combination of corticosteroid and methotrexate monitored by 18F-fluoro-2-deoxyglucose positron emission tomography: case series

Background

The standard treatment for cardiac sarcoidosis (CS) is corticosteroids, including prednisolone (PSL). Previous studies have shown that the addition of methotrexate (MTX) to PSL is effective for steroid-refractory and recurrent cases. ¹⁸F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) is an essential tool for the diagnosis of CS. However, it is unclear whether FDG-PET is useful for detecting recurrence of CS and monitoring the effectiveness of PSL and MTX combination therapy.

Case summary

We detected CS recurrence during PSL treatment using FDG-PET. Patient 1 was accompanied by increased FDG uptake in other organs, Patient 2 was complicated with a decrease in left ventricular ejection fraction, and Patient 3 showed enlargement of the late gadolinium enhancement area, which was compatible with the recurrence of CS. We successfully monitored the inflammation activity by FDG-PET and treated recurrent CS by increasing the PSL dose and adding MTX to suppress inflammation.

Discussion

FDG-PET is useful for detecting CS recurrence and monitoring the effectiveness of PSL and MTX combination therapy. Serial FDG-PET scans indicated that it might be more difficult to suppress inflammation in recurrent CS than in the initial treatment. The use of FDG-PET is necessary to monitor long-term disease activity.

Immunomodulating Therapies in Acute Myocarditis and Recurrent/Acute Pericarditis

The field of inflammatory disease of the heart or "cardio-immunology" is rapidly evolving due to the wider use of non-invasive diagnostic tools able to detect and monitor myocardial inflammation. In acute myocarditis, recent data on the use of immunomodulating therapies have been reported both in the setting of systemic autoimmune disorders and in the setting of isolated forms, especially in patients with specific histology (e.g., eosinophilic myocarditis) or with an arrhythmicburden. A role for immunosuppressive therapies has been also shown in severe cases of coronavirus disease 2019 (COVID-19), a condition that can be associated with cardiac injury and acute myocarditis. Furthermore, ongoing clinical trials are assessing the role of high dosage methylprednisolone in the context of acute myocarditis complicated by heart failure or fulminant presentation or the role of anakinra to treat patients with acute myocarditis excluding patients with hemodynamically unstable conditions. In addition, the explosion of immune-mediated therapies in oncology has introduced new pathophysiological entities, such as immune-checkpoint inhibitor-associated myocarditis and new basic research models to understand the interaction between the cardiac and immune systems. Here we provide a broad overview of evolving areas in cardio-immunology. We summarize the use of new imaging tools in combination with endomyocardial biopsy and laboratory parameters such as high sensitivity troponin to monitor the response to immunomodulating therapies based on recent evidence and clinical experience. Concerning pericarditis, the normal composition of pericardial fluid has been recently elucidated, allowing to assess the actual presence of inflammation; indeed, normal pericardial fluid is rich in nucleated cells, protein, albumin, LDH, at levels consistent with inflammatory exudates in other biological fluids. Importantly, recent findings showed how innate immunity plays a pivotal role in the pathogenesis of recurrent pericarditis with raised C-reactive protein, with inflammasome and IL-1 overproduction as drivers for systemic inflammatory response. In the era of tailored medicine, anti-IL-1 agents such as anakinra and rilonacept have been demonstrated highly effective in patients with recurrent pericarditis associated with an inflammatory phenotype.

Ten Questions Cardiologists Should Be Able to Answer About Cardiac Sarcoidosis: Case-Based Approach and Contemporary Review

Sarcoidosis is an inflammatory multisystemic disease of unknown etiology characterized by the formation of noncaseating epithelioid cell granulomas. Cardiac sarcoidosis might be life-threatening and its diagnosis and treatment remain a challenge nowadays. The aim of this review is to provide an updated overview of cardiac sarcoidosis and, through 10 practical clinical questions and real-life challenging case scenarios, summarize the main clinical presentation, diagnostic criteria, imaging findings, and contemporary treatment.

Activation of cardiac sarcoidosis associated with development of gastric cancer: a case report

Background

The high ¹⁸F-fluorodeoxyglucose (FDG) uptake in sarcoidosis lesions reflects infiltration of inflammatory cells such as macrophages. An increased incidence of cancer in patients with sarcoidosis has been suggested, and some combination of the following mechanisms has been proposed: chronic inflammation, immune dysfunction, shared aetiologic agents, and genetic susceptibility to both cancer and autoimmune diseases.

Case summary

A 73-year-old man was admitted to our hospital due to effort dyspnoea. Initial investigations showed complete atrioventricular block on electrocardiography, basal thinning of the interventricular septum, and preserved left ventricular (LV) systolic function on echocardiography, and late gadolinium enhancement (LGE) in all layers of the basal interventricular septum on cardiac magnetic resonance imaging. FDG positron emission tomography/computerized tomography (FDG-PET/CT) showed no abnormal uptake in the whole-body including myocardium. After discussion, corticosteroid was not initiated then. One year later, he developed stomach adenocarcinoma. Repeated investigations demonstrated enlargement of the LV (LV diastolic diameter 63 mm) and diffuse systolic impairment of LV function (LV ejection fraction 31%) on echocardiography, and abnormal focal uptake at the lateral walls of LV and hilar lymph nodes on FDG-PET/CT imaging. One more year after the surgery for gastric cancer and corticosteroid initiation, echocardiography showed recovery of systolic function and FDG-PET/CT showed no uptake in either the myocardium or hilar lymph nodes.

Discussion

In the present case, it is speculated that the first inflammation which left scarred areas showing LGE was already completed before the first FDG-PET/CT. The development of gastric cancer may be associated with the reactivation of cardiac sarcoidosis.

Pre-Treatment Myocardial 18FDG Uptake Predicts Response to Immunosuppression in Patients With Cardiac Sarcoidosis

OBJECTIVES

This study identified predictors of clinical (CR) and echocardiographic response (ER) following immunosuppressive therapy (IST) in patients with cardiac sarcoidosis (CS).

BACKGROUND

IST has been the cornerstone of treatment for patients with CS and active myocardial inflammation. However, there are little data to explain the variable response to IST in CS.

METHODS

Data of 96 consecutive patients with CS from the Granulomatous Myocarditis Registry were analyzed. All patients underwent a ¹⁸fluorodeoxy glucose positron emission tomography-computed tomography (¹⁸FDG-PET-CT) before initiation of IST. Response was assessed after 4 to 6 months of therapy. CR was defined as an improvement in functional class (New York Heart Association functional class ≥I) and freedom from ventricular arrhythmias and heart failure hospitalizations. ER was defined as an improvement in left ventricular ejection fraction (LVEF) ≥10%. ER was assessed only in patients with a LVEF <50%. Complete responders had no residual myocardial FDG uptake and fulfilled both response criteria. Partial responders fulfilled only 1 response criteria or had residual FDG uptake. Nonresponders did not fulfill either CR or ER criteria. The uptake index (UI) was defined as the product of maximum standardized uptake value and the number of LV segments with abnormal uptake on ¹⁸FDG-PET-CT.

RESULTS

Among 91 patients included in the final analysis, 54.9%, 20.9%, and 24.2% of patients were classified as complete and partial responders and nonresponders, respectively. Cox regression analysis (all responders vs. nonresponders) identified the following as independent predictors of response following immunosuppression: LVEF >40% (hazard ratio: 1.61; 95% confidence interval: 1.06 to 7.69; p = 0.031) and myocardial UI >30 (hazard ratio: 1.28; 95% confidence interval: 1.05 to 6.12; p = 0.010). The final model had a good discriminative power (area under the curve [AUC]: 0.85) and predictive accuracy (sensitivity: 85.5%; specificity: 86.4%). Pre-treatment myocardial UI had a strong positive correlation with change in LVEF following immunosuppression.

CONCLUSIONS

Pre-treatment ¹⁸FDG myocardial uptake was a predictor of CR and ER response to immunosuppression in patients with CS.

Cardiac sarcoidosis: A long term follow up study

BACKGROUND

Prognostic factors are lacking in cardiac sarcoidosis (CS), and the effects of immunosuppressive treatments are unclear.

OBJECTIVES

To identify prognostic factors and to assess the effects of immunosuppressive drugs on relapse risk in patients presenting with CS.

METHODS

From a cohort of 157 patients with CS with a median follow-up of 7 years, we analysed all cardiac and extra-cardiac data and treatments, and assessed relapse-free and overall survival.

RESULTS

The 10-year survival rate was 90% (95% CI, 84-96). Baseline factors associated with mortality were the presence of high degree atrioventricular block (HR, 5.56, 95% CI 1.7-18.2, p = 0.005), left ventricular ejection fraction below 40% (HR, 4.88, 95% CI 1.26-18.9, p = 0.022), hypertension (HR, 4.79, 95% CI 1.06-21.7, p = 0.042), abnormal pulmonary function test (HR, 3.27, 95% CI 1.07-10.0, p = 0.038), areas of late gadolinium enhancement on cardiac magnetic resonance (HR, 2.26, 95% CI 0.25-20.4, p = 0.003), and older age (HR per 10 years 1.69, 95% CI 1.13-2.52, p = 0.01). The 10-year relapse-free survival rate for cardiac relapses was 53% (95% CI, 44-63). Baseline factors that were independently associated with cardiac relapse were kidney involvement (HR, 3.35, 95% CI 1.39-8.07, p = 0.007), wall motion abnormalities (HR, 2.30, 95% CI 1.22-4.32, p = 0.010), and left heart failure (HR 2.23, 95% CI 1.12-4.45, p = 0.023). After adjustment for cardiac involvement severity, treatment with intravenous cyclophosphamide was associated with a lower risk of cardiac relapse (HR 0.16, 95% CI 0.033-0.78, p = 0.024).

CONCLUSIONS

Our study identifies putative factors affecting morbidity and mortality in cardiac sarcoidosis patients. Intravenous cyclophosphamide is associated with lower relapse rates.

Clinical and Imaging Response to Tumor Necrosis Factor Alpha Inhibitors in Treatment of Cardiac Sarcoidosis: A Multicenter Experience

BACKGROUND

Cardiac sarcoidosis (CS) is an increasingly recognized cause of cardiomyopathy; however, data on immunosuppressive strategies are limited. Treatment with tumor necrosis factor (TNF) alpha inhibitors is not well described; moreover, there may be heart failure-related safety concerns.

METHODS

Retrospective multicenter study of patients with CS treated with TNF alpha inhibitors. Baseline characteristics, treatments, and outcomes were adjudicated.

RESULTS

Thirty-eight patients with CS (mean age 49.9 years, 42% women, 53% African American) were treated with TNF alpha inhibitor (30 infliximab, 8 adalimumab). Prednisone dose decreased from time of TNF alpha inhibitor initiation (21.7 ± 17.5 mg) to 6 months (10.4 ± 6.1 mg, P = .001) and 12 months (7.3 ± 7.3 mg, P = .002) after treatment. On pre-TNF alpha inhibitor treatment positron emission tomography with 18-flourodoxyglucose (FDG-PET), 84% of patients had cardiac FDG uptake. After treatment, there was a significant decrease in number of segments involved (3.5 ± 3.8 to 1.0 ± 2.5, P = .008) and maximum standardized uptake value (3.59 ± 3.70 to 0.57 ± 1.60, P = .0005), with 73% of patients demonstrating complete resolution or improvement of cardiac FDG uptake. The left ventricular ejection fraction remained stable (45.0 ± 16.5% to 47.0 ± 15.0%, P = .10). Four patients required inpatient heart failure treatment, and 8 had infections; 2 required treatment cessation.

CONCLUSIONS

TNF alpha inhibitor treatment guided by FDG-PET imaging may minimize corticosteroid use and effectively reduce cardiac inflammation without significant adverse effect on cardiac function. However, infections were common, some of which were serious, and therefore patients require close monitoring for both infection and cardiac symptoms.

Corticosteroid refractory sarcoidosis

A sarcoidosis patient may be refractory to corticosteroid therapy. This may be because corticosteroids are ineffective in relieving the sarcoidosis patient's symptoms/dysfunction or because the clinician has determined that the risks of corticosteroids outweigh their benefits. Interestingly, when corticosteroids truly fail to improve a sarcoidosis patient's condition, it is very rarely because of failure of the drug as an anti-granulomatous agent; rather, it is usually because the patient's symptoms were unrelated to active sarcoid granulomas. In this manuscript, we review the causes of corticosteroid refractory sarcoidosis. The clinician should consider these causes when confronted with a sarcoidosis patient who is either not responding to corticosteroids, developing corticosteroid side-effects, or is at significant risk of developing such side-effects. We believe that determining the cause of corticosteroid refractory sarcoidosis may aid the clinicians in optimizing the care of sarcoidosis patients and clinical researchers in appropriately stratifying patients for clinical trials.

The role of cardiac imaging in the management of non-ischemic cardiovascular diseases in human immunodeficiency virus infection

Infection with human immunodeficiency virus (HIV) has become the pandemic of the new century. About 36.9 million people are living with HIV worldwide. The introduction of antiretroviral therapy in 1996 has dramatically changed the global landscape of HIV care, resulting in significantly improved survival and changing HIV to a chronic disease. With near-normal life expectancy, contemporary cardiac care faces multiple challenges of cardiovascular diseases, disorders specific to HIV/AIDS, and those related to aging and higher prevalence of traditional risk factors. Non-ischemic cardiovascular diseases are major components of cardiovascular morbidity and mortality in HIV/AIDS. Non-invasive cardiac imaging plays a pivotal role in the management of these diseases. This review summarizes the non-ischemic presentation of the HIV cardiovascular spectrum focusing on the role of cardiac imaging in the management of these disorders.

Refractory Sarcoidosis: A Review

Sarcoidosis is a multi-system disease of unknown etiology characterized by granuloma formation in various organs (especially lung and mediastinohilar lymph nodes). In more than half of patients, the disease resolves spontaneously. When indicated, it usually responds to corticosteroids, the first-line treatment, but some patients may not respond or tolerate them. An absence of treatment response is rare and urges for verifying the absence of a diagnosis error, the good adherence of the treatment, the presence of active lesions susceptible to respond since fibrotic lesions are irreversible. That is when second-line treatments, immunosuppressants (methotrexate, leflunomide, azathioprine, mycophenolate mofetil, hydroxychloroquine), should be considered. Methotrexate is the only first-line immunosuppressant validated by a randomized controlled trial. Refractory sarcoidosis is not yet a well-defined condition, but it remains a real challenge for the physicians. Herein, we considered refractory sarcoidosis as a disease in which second-line treatments are not sufficient to achieve satisfying disease control or satisfying corticosteroids tapering. Tumor necrosis alpha inhibitors, third-line treatments, have been validated through randomized controlled trials. There are currently no guidelines or recommendations regarding refractory sarcoidosis. Moreover, criteria defining non-response to treatment need to be clearly specified. The delay to achieve response to organ involvement and drugs also should be defined. In the past ten years, the efficacy of several immunosuppressants beforehand used in other autoimmune or inflammatory diseases was reported in refractory cases series. Among them, anti-CD20 antibodies (rituximab), repository corticotrophin injection, and anti-JAK therapy anti-interleukin-6 receptor monoclonal antibody (tocilizumab) were the main reported. Unfortunately, no clinical trial is available to validate their use in the case of sarcoidosis. Currently, other immunosuppressants such as JAK inhibitors are on trial to assess their efficacy in sarcoidosis. In this review, we propose to summarize the state of the art regarding the use of immunosuppressants and their management in the case of refractory or multidrug-resistant sarcoidosis.

Myocardial Positron Emission Tomography for Evaluation of Cardiac Sarcoidosis: Specialized Protocols for Better Diagnosis

Sarcoidosis is a multisystemic granulomatous disease of unknown etiology with various clinical presentations depending on the organs involved. Since cardiac sarcoidosis (CS) portends a higher risk of morbidity and mortality, early diagnosis and aggressive medical treatment are essential to improve the prognosis. ¹⁸F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) has emerged as an important tool with practical advantages in assessing disease activity and monitoring the treatment response in patients with CS. While it has high sensitivity, it also has great variability in specificity, probably due to normal physiologic myocardial FDG uptake, which interferes with the evaluation and follow-up of CS using FDG-PET. This review details the technical aspects of FDG-PET imaging for evaluating and diagnosing CS, assessing disease activity, and monitoring therapeutic response.

The role of positron emission tomography in the assessment of cardiac sarcoidosis

The myocardium and the cardiovascular system are often involved in patients with sarcoidosis. As therapy should be started as early as possible to avoid complications such as left ventricular dysfunction, a prompt and reliable diagnosis by means of non-invasive tests would be highly warranted. Among other techniques, 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) has emerged as a high sensitive tool to detect sites of inflammation before morphological changes are visible to conventional imaging techniques. We therefore aim at summarizing the most relevant findings in the literature on the use of 18F-fluorodeoxyglucose PET in the diagnostic workup of cardiac sarcoidosis and to underline future perspectives.

Case of isolated cardiac sarcoidosis diagnosed by newly developed abnormal uptake during serial follow-up fluorine-18 fluorodeoxyglucose positron emission tomography

Cardiac sarcoidosis (CS) causes lethal arrhythmia and heart failure and has a poor prognosis; therefore, early detection and early stage treatment are important. However, diagnosis of isolated CS may be difficult in some cases owing to the low sensitivity of myocardial biopsy. Herein, we describe the case of a patient with isolated CS, showing change from negative to positive fluorine‐18 fluorodeoxyglucose (¹⁸F‐FDG) positron emission tomography (PET) uptake results within 9 months. The patient showed rapid reduction in left ventricular systolic function with sustained ventricular tachycardia. The diagnosis of isolated CS is often under‐recognized in clinical practice because it commonly requires the diagnosis of extracardiac disease in the absence of a positive endomyocardial biopsy. The Japanese Circulation Society recently published guidelines for CS diagnosis stating that isolated CS can be clinically diagnosed with positive ¹⁸F‐FDG PET or ⁶⁷Gallium result. In this case, serial follow‐up ¹⁸F‐FDG PET was useful for diagnosing isolated CS.

Arrhythmogenic Inflammatory Cardiomyopathy: A Review

Arrhythmogenic inflammatory cardiomyopathy is a recent clinical description of a subgroup of patients with non-ischaemic cardiomyopathy who are referred to electrophysiologists for evaluation and management of ventricular arrhythmias and are found to have evidence of active cardiac inflammation. The identification of these patients is key, since the aetiology of their arrhythmic burden is likely both related to scar-mediated and direct inflammatory mechanisms, which may have different treatment approaches. Evaluation of these patients starts with a full clinical history and physical examination along with echocardiography, as with most patients with cardiomyopathy, however, additional imaging with fluorodeoxyglucose PET-CT and cardiac MRI is crucial. Medical treatment is aimed at targeting traditional neurohumeral mediators to achieve recovery of ejection fraction, in addition to immunosuppressant medication to directly treat inflammation. While medical treatment alone is successful in many patients, some will require further invasive management with electrophysiologic study and radiofrequency catheter ablation.

Evaluation of FDG PET combined with cardiac MRI for the diagnosis and therapeutic monitoring of cardiac sarcoidosis

AIM

To compare combined 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG)-positron-emission tomography (PET) and cardiac magnetic resonance imaging (CMR) for the diagnosis and therapy monitoring of cardiac sarcoidosis (CS).

MATERIALS AND METHODS

Eighty patients with sarcoidosis and a suspicion of CS who underwent PET and CMR were included retrospectively. PET was undertaken after a low-carbohydrate-high-fat diet in all patients using a combined 16-section PET/computed tomography (CT) camera. PET was considered positive (PET+) in cases of focal or multifocal FDG uptake. CMR was considered positive (CMR+) in cases of subepicardial late gadolinium enhancement (LGE). A subgroup of 50 patients (50/80) was monitored during therapy and classified as responders or non-responders.

RESULTS

Eighty-two percent of patients with PET+ (9/11) also had CMR+ imaging, with good spatial agreement (kappa=0,79; 95% confidence interval [CI]: 0.65-0.94). Twenty-seven percent (22/80) had residual physiological FDG uptake, with a standardised uptake value (SUV) not significantly different compared to the SUV from pathological uptake (6.4 versus 6 respectively, p=0,92). The clinical response was more frequent in patients with baseline PET+ compared to baseline PET- (80% versus 45%, p=0.07). PET findings improved in all cases under treatment (7/7), whereas LGE improved in only 33% of patients (3/9).

CONCLUSION

Due to high risk of false-positive or undetermined findings, PET might be performed as a second-line study in cases of LGE, to assess inflammatory load. In addition, PET seems suitable to predict and assess response under therapy.

Cardiac sarcoidosis - an expert review for the chest physician

Introduction: Sarcoidosis is a multisystem granulomatous disease predominantly affecting the lungs, with increased risk of cardiovascular disease, pulmonary hypertension and cardiac sarcoidosis (CS), the latter due to direct granuloma infiltration. Sarcoidosis is often managed by chest physicians who need to understand the diagnostic pathways and initial management plans for patients with cardiac involvement. Areas covered: The most serious consequence of CS is sudden cardiac death due to ventricular tachyarrhythmias or complete atrioventricular block. Additional complications include atrial arrhythmias and congestive cardiac failure. There are no internationally accepted screening pathways, but a combination of history, clinical examination and ECG detects up to 85% of cases. Newer modalities including signal-averaged ECG and speckle-tracking echocardiography increase identification of patients who require a definitive diagnosis. Early immunosuppression reduces the risk of conduction abnormalities and incidence of supraventricular arrhythmias. Management of ventricular arrhythmias requires antiarrhythmic medications followed by possible catheter ablation and device (ICD) implantation. Expert commentary: Prospective trials are underway to identify the optimum methods for screening, which will guide future international statements on indications for and methods of screening in CS.

Diagnostic value of cardiac magnetic resonance and fluorodeoxyglucose-positron emission tomography for cardiac sarcoidosis with previous myocardial infarction: A case report

RATIONALE

Diagnostic difficulty due to overlapped clinical findings exists in cardiac sarcoidosis (CS) patients who also have coronary artery disease. Since cardiac magnetic resonance (CMR) and fluorodeoxyglucose-positron emission tomography (FDG-PET) evaluate different pathological processes, that is, fibrosis and inflammation respectively, the combination may be useful in such a case.

PATIENT CONCERNS

A 77-year-old man was admitted due to heart failure and advanced atrioventricular block who was previously diagnosed with cutaneous sarcoidosis and old myocardial infarction (MI) with angiographical evidence.

DIAGNOSIS

He was finally diagnosed with CS using CMR and FDG-PET by specifying the myocardial lesion of sarcoidosis.

INTERVENTIONS

He was treated with corticosteroids based on the diagnosis.

OUTCOMES

The focal high uptake on FDG-PET was improved and he had a better clinical course without further cardiac events.

LESSONS

Our case suggests that CMR and FDG-PET are complimentary, and the combination is useful for diagnosis of CS, particularly in cases that have previous MI.

Monitoring the Therapy of Extensive Osseous Sarcoidosis With FDG PET/CT

FDG PET/CT was performed in a 47-year-old man to evaluate possible malignancy of the spine revealed by MRI. The PET images revealed numerous focal FDG activity throughout the skeletal system. In addition, multiple foci of the increased activity in the mediastinal and hilar nodes were noted, suggestive of sarcoidosis, which was proven following biopsy. Therapy for sarcoidosis was initiated. In the subsequent 4 follow-up FDG PET/CT scans, the activity in both the bones and mediastinal/hilar regions fluctuated. However, anatomical abnormality in the bones on the CT images was never visualized during the entire clinical course.

Cardiac Sarcoidosis: A Review of Contemporary Challenges in Diagnosis and Treatment

Sarcoidosis is a systemic disease characterized by noncaseating granulomas and is often a diagnosis of exclusion. The actual prevalence of cardiac sarcoidosis (CS) is unknown, as studies have demonstrated mixed data. CS may be asymptomatic and is likely more frequently encountered than previously thought. Sudden death may often be the presenting feature of CS. Most deaths attributed to CS are caused by arrhythmias or conduction system disease, and congestive heart failure may occur. Current expert consensus on diagnosis of CS continues to rely on endomyocardial biopsy, in the absence of which, histologic proof of extracardiac sarcoid involvement is necessitated. Emergence of newer noninvasive imaging modalities such as cardiac magnetic resonance imaging and positron emission tomography, have become increasingly popular tools utilized in patients with both clinical and asymptomatic CS, and have demonstrated good diagnostic capability. The main therapeutic approaches in patients with CS can be broadly divided into the following 2 categories: pharmacological management and invasive or device oriented. However, much remains unknown about the optimal screening protocols of asymptomatic patients with extracardiac sarcoidosis and treatment of biopsy-proven CS. Our knowledge about CS has amplified significantly over the last 30 years and the growing realization that this process is often asymptomatic is paving the way for better screening protocols and earlier detection of this serious condition.

Update on Treatment in Cardiac Sarcoidosis

OPINION STATEMENT

The prevalence of cardiac sarcoidosis has exponentially increased over the past decade, primarily due to increased awareness and diagnostic modalities for the disease entity. Despite an expanding patient cohort, the optimal management of cardiac sarcoidosis remains yet to be established with a significant lack of prospective trials to support current practice. Corticosteroids remain first-line treatment of this disorder, and we recommend that immunosuppressive therapy should be initiated in all patients diagnosed with cardiac sarcoidosis. Additional pharmacotherapy may be necessary based on disease manifestations and response to treatment. The use of nuclear imaging with ¹⁸fluorodeoxyglucose (¹⁸FDG) positron emission tomography (PET) to guide treatment has become more common, but lacks rigorous data from larger cohorts. Whether an improvement in inflammatory burden as assessed by ¹⁸FDG-PET is correlated with clinical outcomes is as yet unproven. Device therapy with implantable-cardioverter defibrillators should be considered in all cardiac sarcoidosis patients for either primary or secondary prevention of ventricular arrhythmias and cardiac death.