Isolated cardiac sarcoidosis: A focused review of an under-recognized entity

Review: Contrast-enhanced magnetic resonance in the diagnosis and management of cardiac sarcoidosis

Sarcoidosis is a relatively rare inflammatory condition which potentially carries high morbidity and substantial mortality. Due to the fact that it does not subject patients to ionizing radiation, has high temporal, spatial and contrast resolutions, cardiovascular magnetic resonance imaging (CMR) has become an important diagnostic and prognostic modality in the evaluation for cardiac involvement in this condition. This review provides relevant clinical and pathophysiological background on cardiac sarcoidosis, whilst detailing the role of CMR imaging in the diagnosis, and management of this condition.

Atypical presentation of cardiac sarcoidosis: role of multimodality imaging and review of literature

Cardiac sarcoidosis (CS) is challenging to determine, consequently is under-recognised in clinical practice. The accurate prevalence of CS is possibly underestimated due to unspecific symptoms, subclinical illness and the dearth of universally accepted diagnostic criteria. Totally, non-invasive diagnosis of CS was proposed in 2015 by the Japanese Ministry of Health and Welfare using positron emission tomography and cardiac MRI findings as major criteria and substituting histological verification. We present a case of a 60-year-old woman with pulmonary sarcoidosis presenting with progressively worsening palpitations and recurrent syncope. Her initial evaluation at another hospital facility revealed normal cardiac testing. A detailed evaluation with echocardiography and cardiac MRI helped us arrive at the diagnosis of CS, which resulted in appropriate treatment and resolution of symptoms. We discuss CS in general, the clinical disease, diagnostic algorithms, latest guidelines and management.

Radionuclide Imaging for Cardiac Sarcoidosis: Much Potential Benefit, but Still Much to Do

Sarcoidosis, a multi-organ inflammatory condition commonly involving the heart and leading to high morbidity and mortality, is increasingly prevalent. PET imaging with ¹⁸F-FDG in conjunction with perfusion imaging is increasingly used for diagnosis, disease characterization, and to guide and follow treatment. However, various challenges remain with regard to protocols, interpretation of image findings, and how best to use test results to guide and monitor therapy. Further investigations of the testing technique, as well as better understanding of disease pathophysiology, are needed for better image utility in order to effectively improve patient outcome.

Imaging of myocarditis and inflammatory cardiomyopathies

Myocarditis encompasses a wide range of myocardial inflammatory diseases, including acute myocarditis, chronic myocarditis and inflammatory cardiomyopathies, and myocardial inflammation associated with other cardiomyopathies. Because of this heterogeneity in clinical presentation, and the infrequent use of endomyocardial biopsy, cardiac imaging has gradually acquired a key role in the non-invasive detection of myocardial inflammation, the assessment of aetiology and the management of specific therapies. This article summarizes the issue of myocarditis and myocardial inflammation in clinical practice, and reviews the role of different non-invasive imaging techniques in the exploration of myocardial inflammation.

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.

Diagnosis and Therapy of Cardiac Sarcoidosis: A Clinical Perspective

Cardiac sarcoidosis, either as part of a systemic process or in its isolated form, is an important and increasingly recognized disorder. It is associated with high rates of morbidity and mortality, including sudden cardiac death. Early recognition and prompt initiation of treatment is life-saving. A team approach, involving general cardiologists, cardiac electrophysiologists, cardiac imaging specialists and radiologists, is the key to best diagnose and manage this complex disorder. Advanced cardiac imaging with PET and MRI is useful for both diagnosis and managment of therapy. Treatment for this disorder involves immunosuppresant therapy, ICDs, and guideline-directed medical therapy of congestive heart failure.

Cardiac sarcoidosis: Case presentation and Review of the literature

Cardiac sarcoidosis usually occurs in the context of systemic disease; however, isolated cardiac involvement can occur in up to 25% of cases and tends to be clinically silent. When symptoms are present, they are often nonspecific and occasionally fatal, representing a diagnostic challenge. A high index of clinical suspicion and the integration of appropriate imaging, laboratory, and pathologic findings is always required. Treatment aims to control the systemic inflammatory condition while preventing further cardiac damage. However, even with adequate diagnosis and treatment strategies, prognosis remains poor. We describe the case of a patient who presented with cardiac symptoms, whose initial examination was unrevealing. Diagnosis was made retrospectively based on later systemic manifestations that revealed characteristic sarcoidosis findings.

Advanced cardiovascular imaging for the evaluation of cardiac sarcoidosis

Cardiac sarcoidosis (CS) remains an intriguing infiltrating disorder and one of the most important forms of inflammatory cardiomyopathy. Identification of patients with CS is of extreme importance because they are at higher risk of sudden death, and heart-failure progression. And while it remains a diagnostic conundrum, a great amount of experience has been accumulated over the last decade with the advent of fluorine-18 fluorodeoxyglucose positron emission tomography and cardiac magnetic resonance with late gadolinium enhancement imaging. They have both proven to be advanced imaging techniques that provide important, and often complementary, diagnostic and prognostic information for the management of CS. However, they have also shown to have limitations, and, thus, there is a continued need for developing more specific imaging probes for identifying cardiac inflammation. The aim of the present manuscript is to provide the reader with a better understanding of the histopathology of the disease, how this potentially relates to noninvasive imaging detection, and the best strategies available for the diagnosis and management of patients with CS.

Cardiac Sarcoidosis

Clinical and subclinical cardiac sarcoidosis (CS) remains diagnostically challenging as the sensitivity and specificity of the diagnostic modalities are limited. The Japanese Ministry of Health and Welfare criteria and the Heart Rhythm Society expert consensus statement on CS are the most common guidelines used to diagnose CS. However, they are mostly based on expert opinions and lack clinical trial validation. The emergence and increase use of newer imaging modalities such as cardiac magnetic resonance and positron emission tomography may give valuable information for accurate diagnosis and assessment of treatment response in CS patient. Although immunosuppressive therapies, particularly corticosteroids, have been proposed as the mainstay of treatment in CS, there is paucity of data on the optimal initiation, duration, and dosage of immunosuppressive therapies. Recommendations are mostly based on small observational studies. Further studies are warranted to better characterize the use of immunosuppressive therapies in this patient population. Device therapies such as implantable cardioverter-defibrillators are usually recommended for patient with clinical CS. In conclusion, this article synthesizes the current best evidence of utilizing various imaging modalities to diagnose CS and summarizing the main therapeutic approaches to manage and treat CS.

Echocardiography in Sarcoidosis

PURPOSE OF REVIEW

Cardiac sarcoidosis (CS) is associated with significant morbidity and mortality. The diagnosis of CS is challenging and typically one that is only entertained after many other conditions have been ruled out. A high index of suspicion is necessary in order to correctly determine appropriate testing for the disease. Transthoracic echocardiography is the most readily available imaging modality available to help establish a diagnosis in a potential patient. However, no one echocardiographic feature is pathognomonic.

RECENT FINDINGS

On echocardiography, unusual wall motion abnormalities, which do not fit a classic coronary distribution, along with diastolic dysfunction may alert one to the presence of cardiac sarcoid, particularly in the right clinical context. Myocardial strain imaging on echocardiography may increase the sensitivity of identifying cardiac sarcoidosis. Alternative imaging with cardiac magnetic resonance imaging or positron emission tomography have become more frequently utilized to establish a diagnosis of CS. Cardiac sarcoidosis remains a difficult condition to diagnose. However early diagnosis is critical to decrease the associated high mortality. Endomyocardial biopsy is highly specific but lacks sensitivity due to the patchy nature of the granulomatous deposition. Thus, imaging plays a role in diagnosis as well as for follow-up. Echocardiography remains an hallmark during the workup for CS. Decreased sensitivity of echocardiography has facilitated the use of other techniques to establish the presence of CS.

Case Study: Cardiac sarcoidosis resolved with Mycobacterium avium paratuberculosis antibiotics (MAP)

Background: The author presents a clinical history and personal case study following his diagnosis of inactive sarcoidosis in 2004, followed by an acute episode of cardiac sarcoidosis (CS) in 2012 which resulted in complete heart block, cardiac myopathy, heart failure and insertion of an implantable cardioverter defibrillator (ICD) pacemaker. Methods: Following a detailed review of the clinical and scientific literature he concluded that sarcoidosis may be a mycobacterial infection and could be treated with anti-MAP antibiotic regime (1) developed to treat Crohn's disease. Findings: After successful culture and identification of viable MAP in his blood, treatment with the MAP antibiotic regime for one year led to complete metabolic resolution of the previously avid cardiac sarcoidosis and no PET evidence of any metabolically active sarcoidosis anywhere. Such reversal of cardiac sarcoidosis has never previously been reported. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 171-177).

Palpitations as a presenting feature of multisystem sarcoidosis

Introduction: Sarcoidosis is described as a systemic condition characterized by non-caseating granulomas in multiple organs. In this report, we present an unusual manifestation of cardiac sarcoidosis and review management strategies.

Case presentation: A 29-year-old African-American man presented with weight loss, fatigue, dyspnea, palpitations, night sweats, painless left eye redness and bilateral leg pain over the course of three months. His physical exam revealed left conjunctival congestion and bilateral crackles on auscultation. Computerized tomography of the chest showed severe parenchymal disease with bilateral fibrotic bands. Bronchoscopy and transbronchial biopsy revealed noncaseating granulomas and multinucleated giant cells, confirming sarcoidosis. Non-sustained ventricular tachycardia developed. Cardiac MRI showed myocardial delayed gadolinium enhancement. He responded to methotrexate and steroid therapy. An implantable cardioverter-defibrillator was placed.

Discussion: Although cardiac sarcoidosis manifests in only 5% of sarcoidosis, autopsy reports indicate subclinical cardiac involvement in up to 30%. There are no established criteria for diagnosis of cardiac sarcoidosis.

Conclusion: Early recognition and diagnosis of cardiac sarcoidosis is challenging but vital due to unpredictability and high risk for malignant cardiac involvement. Newer diagnostic imaging modalities have further aided in earlier identification and prevention of sudden cardiac death.

Isolated cardiac sarcoidosis masquerading as right ventricular outflow tract ventricular tachycardia

A 67-year-old man with coronary artery disease (CAD) and left anterior descending artery (LAD) stent presented with symptomatic monomorphic ventricular tachycardia (VT) at a rate of 190 bpm requiring cardioversion. ECG showed left bundle branch block pattern and inferior axis, suggestive of a right ventricular outflow tract (RVOT) focus rather than left ventricular scar due to LAD territory myocardial infarction (MI). Echocardiography showed normal wall motion. Angiography revealed a patent mid-LAD stent. Cardiac MRI with delayed postcontrast sequence revealed several regions of hyperenhancement abnormality within the basal portion of the interventricular septum. Increased metabolic activity on positron emission tomography confirmed active inflammatory sarcoidosis.Although VTs in patients with prior CAD are likely to be related to either scar or ischaemia, alternative diagnoses (eg, infiltrative disorders, RVOT-VT, arrhythmogenic right ventricular cardiomyopathy) should be considered in patients with an apparent right ventricular focus on ECG.

Inter- and Intraobserver Agreement of 18F-FDG PET/CT Image Interpretation in Patients Referred for Assessment of Cardiac Sarcoidosis

Recent studies have reported the usefulness of ¹⁸F-FDG PET in aiding with the diagnosis and management of patients with cardiac sarcoidosis (CS). However, image interpretation of ¹⁸F-FDG PET for CS is sometimes challenging. We sought to investigate the inter- and intraobserver agreement and explore factors that led to important discrepancies between readers. Methods: We studied consecutive patients with no significant coronary artery disease who were referred for assessment of CS. Two experienced readers masked to clinical information, imaging reports, independently reviewed ¹⁸F-FDG PET/CT images. ¹⁸F-FDG PET/CT images were interpreted according to a predefined standard operating procedure, with cardiac ¹⁸F-FDG uptake patterns categorized into 5 patterns: none, focal, focal on diffuse, diffuse, and isolated lateral wall or basal uptake. Overall image assessment was classified as either consistent with active CS or not. Results: One hundred scans were included from 71 patients. Of these, 46 underwent ¹⁸F-FDG PET/CT with a no-restriction diet (no-restriction group), and 54 underwent ¹⁸F-FDG PET/CT with a low-carbohydrate, high-fat and protein-permitted diet (low-carb group). There was agreement of the interpretation category in 74 of 100 scans. The κ-value of agreement among all 5 categories was 0.64, indicating moderate agreement. For overall clinical interpretation, there was agreement in 93 of 100 scans (κ = 0.85). When scans were divided into the preparation groups, there was a trend toward higher agreement in the low-carb group versus the no-restriction group (80% vs. 67%, P = 0.08). Regarding the overall clinical interpretation, there was also a trend toward greater agreement in the low-carb group versus the no-restriction group (96% vs. 89%, P = 0.08). Conclusion: The interobserver agreement of cardiac ¹⁸F-FDG uptake image patterns was moderate. However, agreement was better regarding overall interpretation of CS. Detailed prescan dietary preparation seemed to improve interobserver agreement.

Role of Imaging in Evaluating Infiltrative Heart Disease

OPINION STATEMENT

Infiltrative heart disease is caused by the deposition of abnormal substances in the heart and can lead to abnormalities in cardiac function and electrical conduction. Advances in non-invasive cardiovascular imaging have allowed for improved diagnosis of infiltrative heart disease, as well as ways to track disease progression or regression, thus enabling a mechanism to follow response to therapy. In this review, we provide an overview of the role of imaging in the diagnosis and management of cardiac sarcoidosis (CS) and cardiac amyloidosis (CA), as well as outline a proposed algorithm for using non-invasive cardiovascular imaging for evaluating these conditions.