Cardiac Sarcoid: A Chameleon Masquerading as Hypertrophic Cardiomyopathy and Dilated Cardiomyopathy in the Same Patient

Imaging in sarcoid disease

Sarcoidosis is a complex multisystem inflammatory disease characterized by noncaseating granulomas and variable clinical manifestations, most commonly affecting the lungs, skin, heart, and nervous system. Imaging is central in its diagnosis, staging, and management, providing essential insights into organ involvement and disease activity. Pulmonary manifestations remain the hallmark, with modalities such as high-resolution chest computed tomography (CT) and chest radiography offering critical diagnostic clues. Imaging techniques, including Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) and cardiac magnetic resonance imaging, are invaluable for identifying cardiac and systemic involvement, including cutaneous and musculoskeletal, while abdominal MRI and ultrasound help delineate hepatic and splenic manifestations. Neurosarcoidosis requires MRI for precise evaluation, supplemented by FDG-PET to guide biopsy and monitor treatment response. This chapter synthesizes the imaging features of sarcoidosis across organ systems, emphasizing practical approaches to diagnosis and management while identifying key areas for future research.

Cardiac Sarcoidosis and Inherited Cardiomyopathies: Clinical Masquerade or Overlap?

Cardiac sarcoidosis (CS) and inherited cardiomyopathies (inherited CM) are associated with advanced heart failure, cardiac conduction defects, ventricular arrhythmias and sudden cardiac death. Both conditions can have similar clinical presentations. Differentiating between the two disease cohorts is important in delivering specific management to patients, such as immunosuppressive therapy for CS patients and genetic screening for inherited CM. In this review, we examined the existing evidence on the overlap between CS and common inherited CM, such as hypertrophic cardiomyopathy, arrhythmogenic cardiomyopathy, restrictive cardiomyopathy and dilated cardiomyopathy. In patients where both CS and inherited CM were implicated, CS tended to be diagnosed much later, often when patients presented with complications warranting a workup or cardiac histological confirmation. CS can masquerade as an inherited CM, leading to delays in the instigation of CS therapy. Confirmed dual pathology overlap between inherited CM and CS is rarer. Advanced cardiac imaging, such as cardiovascular magnetic resonance, plays an important role in the clinical workup of both CS and inherited CM. However, findings on cardiac imaging alone often cannot differentiate between the two conditions. Definitive differentiation between CS and inherited CM requires both clinical experience and, at times, a myocardial biopsy.

Coronary microvascular disease in hypertrophic and infiltrative cardiomyopathies

Pathologic hypertrophy of the cardiac muscle is a commonly encountered phenotype in clinical practice, associated with a variety of structural and non-structural diseases. Coronary microvascular disease is considered to play an important role in the natural history of this pathological phenotype. Non-invasive imaging modalities, most prominently positron emission tomography and cardiac magnetic resonance, have provided insights into the pathophysiological mechanisms of the interplay between hypertrophy and the coronary microvasculature. This article summarizes the current knowledge on coronary microvascular dysfunction in the most frequently encountered forms of pathologic hypertrophy.

Sarcoid Heart Disease: Review of Current Knowledge

Sarcoidosis is a granulomatous disease with the potential of multiple organ system involvement and its etiology remains unknown. Cardiac involvement is associated with worse clinical outcome, and has been reported to be 20-30% in white and as high as 58% in Japanese populations with sarcoidosis. Clinical manifestations of cardiac sarcoidosis highly depend on the extent and location of granulomatous inflammation. The most frequent presentations include heart block, tachyarrhythmia, or heart failure. Endomyocardial biopsy is the most specific diagnostic test, but has poor sensitivity due to often patchy involvement. The diagnosis of cardiac sarcoidosis remains challenging due to nonspecific imaging findings. Both 18 F-fluorodeoxyglucose-positron emission tomography (FDG-PET) and cardiac magnetic resonance imaging can be used to evaluate cardiac sarcoidosis, but evaluate different stages of the disease process. FDG-PET detects metabolically active inflammatory cells while cardiac magnetic resonance imaging with late gadolinium enhancement reveals areas of myocardial necrosis and fibrosis. Aggressive therapy of symptomatic cardiac sarcoidosis is often sought due to the high risk of sudden death and/or progression to heart failure. Prednisone 20-40 mg a day is the recommended initial treatment. In refractory or severe cases, higher doses of prednisone, 1-1.5 mg/kg/d (or its equivalent) and addition of a steroid-sparing agent have been utilized. Methotrexate is added most commonly. Long-term improvement has been reported with the use of a combination of weekly methotrexate and prednisone versus prednisone alone. After initiation of treatment, a cardiac FDG-PET scan may be performed 2-3 months later to assess treatment response.

Myocardial findings evaluated by echocardiography in cardiac sarcoidosis: A report of seven cases

Sarcoidosis is a multisystem granulomatous disease of unknown cause. With cardiac sarcoidosis (CS), patients represent a wide range of cardiac manifestations from subtle to overt morphological and functional abnormalities. The advent of ultrasound technologies has enabled to identify not only typical findings to CS such as basal thinning of the ventricular septum, but also subclinical myocardial alterations. Based on our recent experiences, we currently introduce a variety of myocardial manifestations evaluated by echocardiography on seven CS patients being selected. Most of the patients exhibited typical cardiac involvement and the remaining fairly unusual.

Sarcoidosis-Related Cardiomyopathy: Current Knowledge, Challenges, and Future Perspectives State-of-the-Art Review

The prevalence of sarcoidosis-related cardiomyopathy is increasing. Sarcoidosis impacts cardiac function through granulomatous infiltration of the heart, resulting in conduction disease, arrhythmia, and/or heart failure. The diagnosis of cardiac sarcoidosis (CS) can be challenging and requires clinician awareness as well as differentiation from overlapping diagnostic phenotypes, such as other forms of myocarditis and arrhythmogenic cardiomyopathy. Clinical manifestations, extracardiac involvement, histopathology, and advanced cardiac imaging can all lend support to a diagnosis of CS. The mainstay of therapy for CS is immunosuppression; however, no prospective clinical trials exist to guide management. Patients may progress to developing advanced heart failure or ventricular arrhythmia, for which ventricular assist device therapies or heart transplantation may be considered. The existing knowledge gaps in CS call for an interdisciplinary approach to both patient care and future investigation to improve mechanistic understanding and therapeutic strategies.

Arrhythmias Associated with Inflammatory Cardiomyopathies

Purpose of review

To provide an approach to the diagnosis and treatment of arrhythmias associated with inflammatory cardiomyopathies.

Recent findings

Inflammatory cardiomyopathies are increasingly recognized as the etiology of both ventricular and supraventricular arrhythmias. There have been recent studies providing novel insights into the pathogenesis of arrhythmias in inflammatory cardiomyopathies and exploring the role of various diagnostic tools and treatment strategies.

Summary

Patients with inflammatory cardiomyopathies often present with one or more arrhythmias, including atrioventricular block, atrial and ventricular tachyarrhythmias, and occasionally sudden cardiac death. Given dynamic pathophysiology and heterogeneous presentation, the management of arrhythmias in these patients presents unique challenges. We review the current approach to the diagnosis and treatment of arrhythmias in this challenging cohort of patients with an emphasis on cardiac sarcoidosis.

Supplementary Information

The online version of this article (10.1007/s11936-020-00871-5) contains supplementary material, which is available to authorized users.

The Multi-modality Cardiac Imaging Approach to Cardiac Sarcoidosis

BACKGROUND

Sarcoidosis is a multisystem granulomatous disease with a neglected but high prevalence of life-threatening cardiac involvement.

DISCUSSION

The clinical presentation of Cardiac Sarcoidosis (CS) depends upon the location and extent of the granulomatous inflammation, with left ventricular free wall the most common location followed by interventricular septum. The lack of a diagnostic gold standard and the unpredictable risk of sudden cardiac death pose serious challenges for the validation of accurate and effective screening test and the management of the disease. In the last few years advanced cardiac imaging modalities such as Cardiac Magnetic Resonance (CMR) and Positron Emission Tomography (PET) have significantly improved our knowledge and understanding of CS, and have also contributed in risk stratification, assessment of inflammatory activity and therapeutic monitoring of the disease.

CONCLUSION

In this review, we will discuss the state of the art in the diagnosis of CS focusing on the role and importance of multi-modality cardiac imaging.

Cardiac Sarcoidosis

Approximately 5% of patients with sarcoidosis will have clinically manifest cardiac involvement presenting with one or more of ventricular arrhythmias, conduction abnormalities, and heart failure. It is estimated that another 20 to 25% of pulmonary/systemic sarcoidosis patients have asymptomatic cardiac involvement (clinically silent disease). Cardiac presentations can be the first (and/or an unrecognized) manifestation of sarcoidosis in a variety of circumstances. Immunosuppression therapy (usually with corticosteroids) has been suggested for the treatment of clinically manifest cardiac sarcoidosis (CS) despite minimal data supporting it. Positron emission tomography imaging is often used to detect active disease and guide immunosuppression. Patients with clinically manifest disease often need device therapy, typically with implantable cardioverter defibrillators (ICDs). The extent of left ventricular dysfunction seems to be the most important predictor of prognosis among patients with clinically manifest CS. In the current era of earlier diagnosis, modern heart failure treatment, and use of ICD therapy, the prognosis from CS is much improved. In a recent Finnish nationwide study, 10-year cardiac survival was 92.5% in 102 patients.

The Many Faces of Cardiac Sarcoidosis

OBJECTIVES

The objective of this study was to review and illustrate the sometimes diagnostically challenging features of cardiac sarcoidosis. We emphasize variable phenotypes presented at explant and biopsy evaluation and review literature regarding ancillary clinical and pathologic studies to enhance diagnostic accuracy.

METHODS

A literature review was performed and two cardiac sarcoidosis cases were illustrated.

RESULTS

Our cases and literature review demonstrate the pathologic spectrum of cardiac sarcoidosis. Irregular left ventricular free wall involvement is most common, followed by the interventricular septum and right ventricle. Although granulomas are often composed of tight epithelioid macrophage aggregates, early granulomas comprise loosely associated macrophages with lymphocyte predominance. Chronic disease leads to fibrosis and end-stage heart failure. Sampling errors and variable histology cause low endomyocardial biopsy sensitivity.

CONCLUSIONS

Current guidelines use clinical, radiologic, and immunohistologic criteria for diagnosing cardiac sarcoidosis. Knowledge of these guidelines will assist pathologists in making accurate diagnosis of this disease.

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.

Differential diagnosis of thickened myocardium: an illustrative MRI review

Objectives

The purpose of this article is to describe the key cardiac magnetic resonance imaging (MRI) features to differentiate hypertrophic cardiomyopathy (HCM) phenotypes from other causes of myocardial thickening that may mimic them.

Conclusions

Many causes of myocardial thickening may mimic different HCM phenotypes. The unique ability of cardiac MRI to facilitate tissue characterisation may help to establish the aetiology of myocardial thickening, which is essential to differentiate it from HCM phenotypes and for appropriate management.

Teaching points

• Many causes of myocardial thickening may mimic different HCM phenotypes.

• Differential diagnosis between myocardial thickening aetiology and HCM phenotypes may be challenging.

• Cardiac MRI is essential to differentiate the aetiology of myocardial thickening from HCM phenotypes.

Cardiac Involvement in Sarcoidosis Deaths in Wayne County, Michigan: A 20-Year Retrospective Study

BACKGROUND

Sarcoidosis is a disease of unknown etiology characterized by the formation of noncaseating, nonnecrotizing granulomas in various organ systems.

METHODS

Reviews of 84 cases of natural death with sarcoidosis between the years 1996 and 2017 autopsied at Wayne County.

RESULTS

The median age of decedents was 44 years (29 - 59 years of age). Blacks comprised 95% of the cohort, and 52% were female. Sarcoidosis or direct sequelae were the cause of death in 79% of cases. Twenty-nine percent of patients had a documented history of sarcoidosis and 70% of patients had evidence of systemic sarcoidosis. The most common sites of involvement were lungs or hilar lymph nodes (92%), heart (45%), liver (39%), and spleen (30%). Decedents with cardiac involvement were more likely to have no documented history of sarcoidosis (87% vs. 59%, p=0.004), more likely to have died of a sarcoidosis-related cause (97% vs. 65%, p<0.001), and died at a younger mean age (41 years vs. 46 years, p=0.001). In addition, individuals with cardiac involvement commonly had concurrent multiorgan involvement including lungs (90%), lymph nodes (38%), liver (40%), spleen (32%), and kidneys (7%).

CONCLUSIONS

Cardiac sarcoidosis is a uniquely poor prognostic factor and carries an increased risk of sudden death as shown by a disproportionate representation among medical examiner cases of sarcoidosis. Our findings suggest that approximately 40% may have asymptomatic cardiac involvement. The distribution of sarcoidosis within our cohort suggests that there is potentially a large undiagnosed and/or underdiagnosed demographic within large urban centers, such as Detroit, Michigan.

Cardiac manifestations of sarcoidosis: diagnosis and management

Approximately 5% of patients with sarcoidosis will have clinically manifest cardiac involvement presenting with one or more of ventricular arrhythmias, conduction abnormalities, and heart failure. Cardiac presentations can be the first (and/or an unrecognized) manifestation of sarcoidosis in a variety of circumstances. Cardiac symptoms are usually dominant over extra-cardiac as most patients with clinically manifest disease have minimal extra-cardiac disease and up to two-thirds have isolated cardiac sarcoidosis (CS). It is estimated that another 20-25% of pulmonary/systemic sarcoidosis patients have asymptomatic cardiac involvement (clinically silent disease). The extent of left ventricular dysfunction seems to be the most important predictor of prognosis among patients with clinically manifest CS. In addition, the extent of myocardial late gadolinium enhancement is emerging as an important prognostic factor. The literature shows some controversy regarding outcomes for patients with clinically silent CS and larger studies are needed. Immunosuppression therapy (usually with corticosteroids) has been suggested for the treatment of clinically manifest CS despite minimal data supporting it. Fluorodeoxyglucose Positron Emission Tomography imaging is often used to detect active disease and guide immunosuppression. Patients with clinically manifest disease often need device therapy, typically with implantable cardioverter defibrillators.

Cardiac Sarcoidosis

Clinically manifest cardiac involvement occurs in perhaps 5% of patients with sarcoidosis. The 3 principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. An estimated 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic cardiac involvement (clinically silent disease). In 2014, the first international guideline for the diagnosis and management of CS was published. In patients with clinically manifest CS, the extent of left ventricular dysfunction seems to be the most important predictor of prognosis. There is controversy in published reports as to the outcome of patients with clinically silent CS. Despite a paucity of data, immunosuppression therapy (primarily with corticosteroids) has been advocated for the treatment of clinically manifest CS. Device therapy, primarily with implantable cardioverter-defibrillators, is often recommended for patients with clinically manifest disease.

Sublocalization of Cardiac Involvement in Sarcoidosis and Surgical Exclusion in Patients With Congestive Heart Failure

BACKGROUND

In sarcoidosis, cardiac involvement can cause fatal conditions such as left ventricular (LV) dysfunction and rhythm disturbance. We surgically treated critical patients with congestive heart failure due to cardiac sarcoidosis.

METHODS

During 14 years, 384 patients with nonischemic dilated cardiomyopathy were operated. Among them, 14 patients (3.6%) with New York Heart Association (NYHA) class IV (male/female, 3/11; 57 ± 11 years) caused by sarcoidosis underwent surgery (elective/emergent, 12/2). The akinetic lesion, as identified by speckle-tracking echocardiography, was excluded.

RESULTS

Localization of akinetic lesions was achieved in 13 patients (93%). In the short axis, lesional distribution was higher in the anterior (62%) and septal segments (54%) when compared with the posterior (31%) and lateral segments (23%). Along the long axis, regional distribution was higher in the mid (85%) and apical segments (69%) when compared with the basal segment (31%). The main lesions were excluded by septal anterior ventricular exclusion (n = 5), posterior restoration procedure (n = 3), endoventricular circular patch plasty (n = 3), and linear resection (n = 2). Mitral valve surgery included mitral valve plasty (n = 7) and replacement (n = 7). In patients undergoing elective surgery, early results showed that 10 patients survived (83%) and NYHA class improved (6 patients in class II and 4 in class III). Patients who underwent emergent surgery did not survive. The observation period was 55 ± 59 months in survivors. During follow-up, 4 patients died after 42 ± 48 months. The other 5 patients have survived for 71 ± 61 months. The 3- and 5-year survival rates were 65% and 52%, respectively.

CONCLUSIONS

Sarcoidosis can result in sublocalized LV involvement, which can be surgically excluded.