Cardiac sarcoidosis: clinical manifestations, imaging characteristics, and therapeutic approach

Heartbeats in Distress: Unveiling Cardiac Sarcoidosis Through Palpitations

Cardiac sarcoidosis (CS), a rare complication of systemic sarcoidosis, can have subtle or no symptoms. It is characterized by granuloma formation in the myocardium, which can occur in isolation or alongside systemic sarcoidosis. Clinical manifestations include conduction system disorders (e.g., atrioventricular block and ventricular tachyarrhythmia), heart failure, and sudden cardiac death. Timely evaluation and screening for CS are crucial, especially in systemic sarcoidosis patients with limited symptoms. We present the case of a 50-year-old African-American male diagnosed with cardiac sarcoidosis following a recent diagnosis of pulmonary sarcoidosis after experiencing tachycardia for two years, as confirmed by imaging studies.

An mTORC1-Dependent Mouse Model for Cardiac Sarcoidosis

Background Sarcoidosis is an inflammatory, granulomatous disease of unknown cause affecting multiple organs, including the heart. Untreated, unresolved granulomatous inflammation can lead to cardiac fibrosis, arrhythmias, and eventually heart failure. Here we characterize the cardiac phenotype of mice with chronic activation of mammalian target of rapamycin (mTOR) complex 1 signaling in myeloid cells known to cause spontaneous pulmonary sarcoid-like granulomas. Methods and Results The cardiac phenotype of mice with conditional deletion of the tuberous sclerosis 2 (TSC2) gene in CD11c+ cells (TSC2fl/flCD11c-Cre; termed TSC2KO) and controls (TSC2fl/fl) was determined by histological and immunological stains. Transthoracic echocardiography and invasive hemodynamic measurements were performed to assess myocardial function. TSC2KO animals were treated with either everolimus, an mTOR inhibitor, or Bay11-7082, a nuclear factor-kB inhibitor. Activation of mTOR signaling was evaluated on myocardial samples from sudden cardiac death victims with a postmortem diagnosis of cardiac sarcoidosis. Chronic activation of mTORC1 signaling in CD11c+ cells was sufficient to initiate progressive accumulation of granulomatous infiltrates in the heart, which was associated with increased fibrosis, impaired cardiac function, decreased plakoglobin expression, and abnormal connexin 43 distribution, a substrate for life-threatening arrhythmias. Mice treated with the mTOR inhibitor everolimus resolved granulomatous infiltrates, prevented fibrosis, and improved cardiac dysfunction. In line, activation of mTOR signaling in CD68+ macrophages was detected in the hearts of sudden cardiac death victims who suffered from cardiac sarcoidosis. Conclusions To our best knowledge this is the first animal model of cardiac sarcoidosis that recapitulates major pathological hallmarks of human disease. mTOR inhibition may be a therapeutic option for patients with cardiac sarcoidosis.

[Imaging diagnostics of cardiac sarcoidosis]

Cardiac involvement is clinically apparent in approximately 5% of all patients with systemic sarcoidosis, whereas evidence of cardiac involvement by imaging studies can be found in approximately 20% of cases. Occasionally, isolated cardiac sarcoidosis is encountered and is the only sign of the disease. The most frequent cardiac manifestations of the multifocal granulomatous inflammation include atrioventricular (AV) blocks and other conduction disorders, ventricular arrhythmias, sudden cardiac death and left and right ventricular wall disorders. Accordingly, symptoms that should raise suspicion include palpitations, lightheadedness and syncope. The diagnostic approach to cardiac sarcoidosis is not straightforward. Typical echocardiographic findings include regional thinning and contraction abnormalities particularly in basal, septal and lateral locations. Infrequently, myocardial hypertrophy may be present; however, the sensitivity of echocardiography is low and cardiac sarcoidosis can be present even when an echocardiogram is unrevealing. Cardiac magnetic resonance imaging (MRI) frequently shows late gadolinium enhancement (LGE) in a multifocal pattern often involving the basal septum and lateral walls. The sensitivity and specificity of MRI for detecting cardiac sarcoidosis are high. Fluorodeoxyglucose positron emission tomography (FDG-PET) plays an important role in the diagnostic algorithm due to its ability to visualize focal inflammatory activity both in the myocardium and in extracardiac locations. This may help target the optimal location for biopsy in order to obtain histologic proof of sarcoidosis and can also be used to follow the response to anti-inflammatory treatment. Notably, the sensitivity of endomyocardial biopsy is poor due to the patchy nature of myocardial involvement. In clinical practice, either histologic evidence of noncaseating granulomas from the myocardium or evidence from extracardiac tissue in combination with typical cardiac imaging findings are required to establish the diagnosis.

Optimal left ventricular ejection fraction in risk stratification of patients with cardiac sarcoidosis

AIMS

Identifying patients with cardiac sarcoidosis (CS) who are at an increased risk of sudden cardiac death (SCD) poses a clinical challenge. We sought to identify the optimal cutoff for left ventricular ejection fraction (LVEF) in predicting ventricular arrhythmia (VA) and all-cause mortality and to identify clinical and imaging risk factors in patients with known CS.

METHODS AND RESULTS

This retrospective cohort included 273 patients with well-established CS. The primary endpoint was a composite of VA and all-cause mortality. A modified receiver operating curve analysis was utilized to identify the optimal cutoff for LVEF in predicting the primary composite endpoint. Cox proportional hazard regression analysis was used to identify independent risk factors of the outcomes. At median follow-up of 7.9 years, the rate of the primary endpoint was 38% (83 VAs and 32 all-cause deaths). The 5-year overall survival rate was 97%. The optimal cutoff LVEF for the primary composite endpoint was 42% in the entire cohort and in subjects without a history of VA. Younger age, history of VA, lower LVEF, and any presence of scar by cardiac magnetic resonance (CMR) imaging and/or positron emission tomography (PET) were found to be independent risk factors for the primary endpoint and for VA, whereas lower LVEF, baseline NT-proBNP, and any presence of scar were independent risk factor of all-cause mortality.

CONCLUSION

Among patients with CS, a mild reduction in LVEF of 42% was identified as the optimal cutoff for predicting VA and all-cause mortality. Prior VA and scar by CMR or PET are strong risk factors for future VA and all-cause mortality.

Cardiac sarcoidosis: a comprehensive review of risk factors, pathogenesis, diagnosis, clinical manifestations, and treatment strategies

Cardiac Sarcoidosis (CS) is a deadly consequence of systemic sarcoidosis that inflames all three layers of the heart, especially the myocardium-clinical signs of CS range from asymptomatic disease to abrupt cardiac death. CS generally remains undiagnosed secondary to a lack of definitive diagnostic criteria, a high percentage of false negative results on endomyocardial biopsy, and ill-defining clinical manifestations of the disease. Consequently, there is a lack of evidence-based recommendations for CS, and the present diagnostic and therapeutic management depend on expert opinion. The aetiology, risk factors, clinical symptoms, diagnosis, and therapy of CS will be covered in this review. A particular emphasis will be placed on enhanced cardiovascular imaging and early identification of CS. We review the emerging evidence regarding the use of Electrocardiograms (ECGs), Magnetic Resonance Imaging (MRI), and Positron Emission Tomography (PET) imaging of the heart to identify and quantify the extent of myocardial inflammation, as well as to guide the use of immunotherapy and other treatment regimens, such as ablation therapy, device therapy, and heart transplantation, to improve patient outcomes.

Cardiac sarcoidosis: is early diagnosis possible? Case report

Cardiac involvement in sarcoidosis is difficult to diagnose due to the asymptomatic course in 95% of cases, the inaccessibility and low information content of a heart biopsy, the absence of pathological disorders in routine examination methods or their non-specificity. At the same time, it is cardiac sarcoidosis, along with damage to the nervous system, that is the main cause of mortality in sarcoidosis. Early diagnosis is of decisive importance for preventing complications associated with heart involvement and choosing the right treatment tactics. The positron emission tomography-computed tomography (PET-CT) is a method that can help the doctor in assessing the prevalence of sarcoidosis and verifying latent localizations in patients with a morphologically confirmed disease. The article describes a case of the use of PET/CT for the diagnosis of cardiac sarcoidosis.

Sarcoidosis and Its Dermatological Manifestations: A Narrative Review

Sarcoidosis is an enigma diagnosed by ruling out other etiologies of granulomatous inflammation. The multisystem manifestations of sarcoidosis and the clinical polymorphism pose a diagnostic challenge to all physicians. The skin is the most commonly affected organ after the lungs in sarcoidosis. Dermatological manifestations can appear before, during, or after systemic involvement, and the type of skin lesion can have prognostic significance. Also, a biopsy of skin lesions is less invasive and more accessible to perform than a biopsy of visceral organs. Thus, in certain ways, cutaneous manifestations can aid in the diagnosis and prognosis of systemic disease. This article has focused on the frequently encountered skin lesions of sarcoidosis along with their prevalence, clinical features, and management.

Cardiac Sarcoidosis: A Unique Presentation

Isolated cardiac sarcoidosis is a rare subset of sarcoidosis, a systemic autoimmune condition primarily found in African American females. The manifestations of cardiac sarcoidosis include atrioventricular and bundle branch blocks, arrhythmias, heart failure, and pericardial effusions, although these complications occur at varying prevalence. The diagnosis of cardiac sarcoidosis requires several different criteria; however, recent literature has focused heavily on imaging modalities such as cardiac magnetic resonance imaging. We present a case of a 42-year-old Caucasian male who was found to have unexplained cardiac arrhythmias and ultimately diagnosed with cardiac sarcoidosis by imaging modalities.

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.

Syncope and Sarcoidosis: A Criss-Cross of Diagnoses

Syncope has a broad range of differential diagnoses. Sarcoidosis, a multisystem inflammatory disorder characterized by the formation of noncaseating granulomas, is a rare but important diagnosis to consider while evaluating patients presenting with presyncopal or syncopal symptoms. Although sarcoidosis is most commonly known to affect the lungs, it is estimated that at least 25% of patients with sarcoidosis have myocardial involvement, with only 5% of these patients showing clinical symptoms. Here, we present the rare case of a Caucasian male patient diagnosed with cardiac sarcoidosis after presenting to the hospital with presyncope. The patient had an internal cardioverter-defibrillator placed during hospitalization and was initiated on prednisone and methotrexate in the outpatient setting. He exhibited clinical and radiographical improvement in the six-month follow-up period after treatment was initiated.

The Role of Multimodality Imaging in Cardiac Sarcoidosis

The etiology and the progression of sarcoidosis remain unknown. However, cardiac sarcoidosis (CS) is significantly associated with a poor prognosis due to the associated congestive heart failure, arrhythmias (such as an advanced atrioventricular block), and ventricular tachyarrhythmia. Novel imaging modalities are now available to detect CS lesions secondary to active inflammation, granuloma formation, and fibrotic changes. ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and cardiac magnetic resonance imaging (CMR) play essential roles in diagnosing and monitoring patients with confirmed or suspected CS. The following focused review will highlight the emerging role of non-invasive cardiac imaging techniques, including FDG PET/CT and CMR.

Sarcoidosis: Pitfalls and Challenging Mimickers

Sarcoidosis, a systemic granulomatous disease of unknown etiology, may mimic other conditions at presentation often resulting in delayed diagnosis. These conditions include infections, neoplasms, autoimmune, cardiovascular, and drug-induced diseases. This review highlights the most common sarcoidosis mimics that often lead to pitfalls in diagnosis and delay in appropriate treatment. Prior to invasive testing and initiating immunosuppressants (commonly corticosteroids), it is important to exclude sarcoid mimickers.

Cardiac sarcoidosis as an incidental finding: A case report

BACKGROUND

This case illustrates the evaluation of a healthy young male with ECG anomalies in a perioperative electrocardiogram (ECG) that ended up with the diagnosis of a severe systemic disease.

CASE

A 28-year-old man was attended at the outpatient cardiology department to perform a preoperative ECG for lacrimal duct obstruction surgery, which showed Q and T negative waves in inferior leads. Echocardiogram and cardiac magnetic resonance (CMR) displayed left ventricular (LV) aneurysm at basal segments of the inferior, posterior, and lateral wall with myocardial thinning and dyskinesia. CMR and thoracic computed tomography (CT) showed bilateral nodular images in parotid glands, cervical, and thoracic lymphadenopathies. All those findings suggested the diagnosis of sarcoidosis, which was supported by Gallium-67 single-photon emission computed tomography (SPECT) results and finally confirmed by skin biopsy.

CONCLUSIONS

The present case highlights the complexity of sarcoidosis diagnosis. This young male was apparently asymptomatic; however, at presentation, he actually had three manifestations of active sarcoidosis: lacrimal duct obstruction, skin lesions, and cervical lymphadenopathies. It is essential to have a low threshold for sarcoidosis suspicion in the setting of unexplained systemic signs and symptoms.

Diagnostic and predictive value of speckle tracking echocardiography in cardiac sarcoidosis

Background

Sarcoidosis is a systemic granulomatous disease that may affect the myocardium. This study evaluated the diagnostic and prognostic value of 2-dimensional speckle tracking echocardiography in cardiac sarcoidosis (CS).

Methods

Eighty-three patients with extracardiac, biopsy-proven sarcoidosis and definite/probable diagnosis of cardiac involvement diagnosed from January 2005 through December 2016 were included. Strain parameters in early stages of CS, in a subgroup of 23 CS patients with left ventricular ejection fraction (LVEF) within normal limits (LVEF> 52% for men: > 54% for women, mean value: 57.3% ± 3.8%) and no wall motion abnormalities was compared with 97 controls (1:4) without cardiac disease. LV and right ventricular (RV) global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain and strain rate (SR) analyses were performed with TomTec software and correlated with cardiac outcomes (including heart failure and arrhythmias). This study was approved by the Mayo Clinic Institutional Review Board, and all patients gave informed written consent to participate.

Results

Mean age of CS patients was 53.6 ± 10.8 years, and 34.9% were women. Mean LVEF was 43.2% ± 12.4%; LV GLS, − 12.4% ± 3.7%; LV GCS, − 17.1% ± 6.5%; LV GRS, 29.3% ± 12.8%; and RV wall GLS, 14.6% ± 6.3%. In the 23 patients with early stage CS with normal LVEF and RV systolic function, strain parameters were significantly reduced when compared with controls (respectively: LV GLS, − 15.9% ± 2.5% vs − 18.2% ± 2.7% [P = .001]; RV GLS, − 16.9% ± 4.5% vs − 24.1% ± 4.0% [P < .001]). A LV GLS value of − 16.3% provided 82.2% sensitivity and 81.2% specificity for the diagnosis of CS (AUC 0.91), while a RV value of − 19.9% provided 88.1% sensitivity and 86.7% specificity (AUC 0.93). Hospital admission and heart failure significantly correlated to impaired LV GLS (> − 14%).

Conclusion

Reduced strain values in the LV GLS and RV GLS can be used in the diagnostic algorithm in patients with suspicion of cardiac sarcoidosis. These values also correlate with adverse cardiovascular events.

[Diagnosis of isolated cardiac sarcoidosis]

Heart involvement in sarcoidosis is diagnosed in vivo in 5-7%, at autopsy in 25% of cases as a manifestation of a systemic process and an isolated one. Difficulties in the diagnosis of isolated sarcoidosis are due to the absence of known causes of the disease and to the lack of specificity of clinical manifestations. The main symptoms include cardiac conduction and rhythm disturbances, cardiomyopathy with the development of heart failure, as well as pericardial involvement. Routine techniques (ECG, EchoCG, daily ECG monitoring) and imaging of the structures of the heart and its function evaluation (MRI, PET, and scintigraphy) are used in diagnosis. A set of clinical, instrumental, and histological data obtained at endomyocardial biopsy may suggest isolated cardiac sarcoidosis with the exception of other diseases.

Magnetic resonance imaging of cardiac sarcoidosis: an evaluation of the cardiac segments and layers that exhibit late gadolinium enhancement

Cardiac sarcoidosis (CS) can cause sudden death, which is the leading cause of mortality in patients with sarcoidosis in Japan. However, it is difficult to diagnose CS because of the lack of a sensitive diagnostic method for the condition. Late gadolinium-enhanced cardiac magnetic resonance (MR) imaging demonstrates improved sensitivity for diagnosing CS. Therefore, it is important to know the late gadolinium-enhancement (LGE) characteristics of CS on cardiac MR images in order to diagnose CS accurately. In this study, we investigated the most common sites of LGE on cardiac MR images in CS. Late gadolinium-enhanced MR images of 9 consecutive patients with CS (obtained between August 2009 and July 2015) were reviewed by two radiologists. The distribution of LGE was evaluated using the American Heart Association 17-segment model of the left ventricle. The LGE in each segment was also classified into 4 patterns according to the myocardial layer in which it occurred (the subepicardial, subendocardial, intramural, and transmural layer patterns). All 9 patients exhibited LGE in their left ventricle, and 70 of 153 (46%) myocardial segments were enhanced. All of the patients displayed LGE in the basal septal wall. The patients' LGE layer patterns were as follows: subepicardial: 40% (28/70), intramural: 30% (21/70), subendocardial: 16% (11/70), and transmural: 14% (10/70). The basal septum wall and subepicardial layer often exhibit LGE on cardiac MR images in CS patients. LGE can be observed in other segments and layers in some cases.

F-18 FDG PET/CT imaging of cardiac and vascular inflammation and infection

INTRODUCTION

Inflammation forms an important core of the aetiopathogenic process involved in many diseases affecting the heart and the blood vessels. These diseases include infections as well as inflammatory non-infectious cardiovascular conditions. The common feature of this is invasion of the heart or blood vessel by inflammatory cells. F-18 2-fluoro 2-deoxy-D glucose (FDG) is an analogue of glucose and like glucose it is taken up by activated inflammatory cells that accumulate at the site of infection. This has formed the basis of the use of F-18 FDG PET/CT in the non-invasive evaluation of human inflammatory diseases.

SOURCES OF DATA

This review is based on the published academic articles as well as our clinical experience.

AREAS OF AGREEMENT

F-18 FDG PET/CT is a useful imaging modality in the evaluation of cardiovascular inflammatory disorders. Accumulation and distribution of F-18 FDG at the site of inflammation/infection corresponds to severity of the inflammation/infection and extent of involvement.

AREAS OF CONTROVERSY

Most studies evaluating utility of F-18 FDG PET/CT in imaging cardiovascular inflammation are small observational studies hence are potentially prone to bias.

GROWING POINTS

Being a hybrid metabolic and morphologic imaging technique, F-18 FDG PET/CT offers combined advantage of complementary anatomic and metabolic information in disease process. This makes it a useful modality in the diagnosis, determination of extent of disease, prognostication as well as treatment monitoring.

AREAS TIMELY FOR DEVELOPING RESEARCH

Larger prospective studies are needed to validate the superiority of F-18 FDG PET/CT imaging over conventional anatomic imaging modalities.

A Diagnostic and Therapeutic Approach to Arrhythmias in Cardiac Sarcoidosis

OPINION STATEMENT

Cardiac sarcoidosis is a protean disease, capable of causing nearly any cardiac abnormality. Electrical abnormalities including heart block and ventricular tachyarrhythmias are some of the most feared manifestations of cardiac sarcoidosis. Despite increasing awareness, cardiac sarcoidosis remains underdiagnosed in clinical practice, and as a result, many patients do not receive potentially disease-altering immunosuppressant therapy. In this review, we discuss cardiac sarcoidosis and its management, focusing diagnostic and therapeutic approaches to arrhythmias in cardiac sarcoidosis.

Sarcoidosis and the heart: A review of the literature

Sarcoidosis is a chronic multisystem disorder without any defined etiology. Cardiac sarcoidosis (CS) is detected in 2-7% of patients with sarcoidosis and more than 20% of the cases of sarcoidosis are clinically silent. Cardiac involvement in systemic sarcoidosis (SS) and isolated cardiac sarcoidosis (iCS) are associated with arrhythmia and severe heart failure (HF) and have a poor prognosis. Early diagnosis of CS and prompt initiation of corticosteroid therapy with or without other immunosuppressants is crucial. Electrocardiography, Holter monitoring, and Doppler echocardiography with speckle tracking imaging can serve as the initial steps to diagnosis of CS. Cardiac magnetic resonance (CMR) imaging and positron emission tomography (PET) are promising techniques for both diagnosis and follow-up of CS. This review discusses the main aspects of cardiac involvement in sarcoidosis.

Role of Cardiac MRI in the Assessment of Cardiomyopathy

OPINION STATEMENT

Combining the diagnostic utilities of cardiac structures, myocardial perfusion, and various tissue characterizing pulse sequence methods in matching scan planes within a single imaging session, cardiac magnetic resonance imaging (CMR) provides a novel interrogation of myocardial physiology and abnormal anatomy from various forms of cardiomyopathy. Establishment of technical imaging standards and clinical adaptation in the past years has helped recognize the distinguishing features of different cardiomyopathies, with CMR currently assuming a pivotal role in the diagnosis of cases of new-onset cardiomyopathy in experienced centers. Quantitative measurements such as ventricular volumes, myocardial iron content, and extent of late gadolinium enhancement can effectively monitor disease status, guide medical therapy, and impact patient outcomes in specific clinical settings. This chapter will aim to summarize these current CMR applications with case examples.

Advances in radionuclide imaging of cardiac sarcoidosis

INTRODUCTION

Radionuclide imaging for the diagnosis and monitoring of cardiac involvement in sarcoidosis has advanced significantly in recent years.

SOURCES OF DATA

This article is based on published clinical guidelines, literature review and our collective clinical experience.

AREAS OF AGREEMENT

Gallium-67 scintigraphy is among the diagnostic criteria for cardiac involvement in systemic sarcoidosis, and it is strongly associated with response to treatment. However, fluorine-18, 2-fluoro-deoxyglucose (FDG) positron emission tomography (PET) is now preferred both for diagnosis and for assessing prognosis.

AREAS OF CONTROVERSY

Most data are from small observational studies that are potentially biased.

GROWING POINTS

Quantitative imaging to assess changes in disease activity in response to treatment may lead to FDG-PET having an important routine role in managing cardiac sarcoidosis.

AREAS TIMELY FOR DEVELOPING RESEARCH

Larger prospective studies are required, particularly to assess the effectiveness of radionuclide imaging in improving clinical management and outcome.