Incidence of Sudden Cardiac Death and Life-Threatening Arrhythmias in Clinically Manifest Cardiac Sarcoidosis With and Without Current Indications for an Implantable Cardioverter Defibrillator

[Arrhythmias in sarcoidosis]

Cardiac sarcoidosis (CS) is difficult to diagnose and often requires a careful evaluation of numerous diagnostic findings. Typical features at initial presentation are a high-grade atrioventricular (AV) block and ventricular tachycardias that cannot be explained by other common entities, especially in younger patients. CS is frequently misdiagnosed and inappropriately treated, which may have deleterious consequences for the patients. In this review article, we focus on special features of the arrhythmias typical of sarcoidosis and also discuss the underlying substrate and the approach in special situations. Furthermore, we provide recommendations from our daily clinical experience, discuss open questions, and explain the need for research.

Molecular Imaging of Heart Failure: An Update and Future Trends

Molecular imaging can detect and quantify pathophysiological processes underlying heart failure, complementing evaluation of cardiac structure and function with other imaging modalities. Targeted tracers have enabled assessment of various cellular and subcellular mechanisms of heart failure aiming for improved phenotyping, risk stratification, and personalized therapy. This review outlines the current status of molecular imaging in heart failure, accompanied with discussion on novel developments. The focus is on radionuclide methods with data from clinical studies. Imaging of myocardial metabolism can identify left ventricle dysfunction caused by myocardial ischemia that may be reversible after revascularization in the presence of viable myocardium. In vivo imaging of active inflammation and amyloid deposition have an established role in the detection of cardiac sarcoidosis and transthyretin amyloidosis. Innervation imaging has well documented prognostic value in predicting heart failure progression and arrhythmias. Tracers specific for inflammation, angiogenesis and myocardial fibrotic activity are in earlier stages of development, but have demonstrated potential value in early characterization of the response to myocardial injury and prediction of cardiac function over time. Early detection of disease activity is a key for transition from medical treatment of clinically overt heart failure towards a personalized approach aimed at supporting repair and preventing progressive cardiac dysfunction.

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.

30-Year Trends in the Incidence, Characteristics, and Outcome of Cardiac Sarcoidosis in a Nationwide Cohort

Background

Cardiac sarcoidosis (CS) is a rare but potentially fatal inflammatory cardiomyopathy.

Objectives

The authors studied temporal changes in the incidence, characteristics, and outcome of CS.

Methods

A retrospective analysis was made of a 30-year nationwide cohort of CS.

Results

The cohort comprised 511 patients with a median age of 52 years and female preponderance (69%). Altogether 77, 166, and 268 cases of CS were diagnosed in years 1988 to 2009, 2010 to 2014, and 2015 to 2019, respectively; the 5-year count of 2015 to 2019 was 134-fold the count of 1990 to 1994 (268/2) and 18-fold the count of 2000 to 2004 (268/15). Prior to 2010, compared with the later periods, CS presented more often with ventricular tachycardia/fibrillation (prevalence 36% vs 19% in 2010-2014 and 11% in 2015-2019, P < 0.001), left ventricular ejection fraction <50% (49%, 35%, and 31%; P = 0.010), and elevation of natriuretic peptides (87%, 57%, and 49%; P < 0.001). On magnetic resonance imaging, late gadolinium enhancement involved a median of 15% (IQR: 11%-22%) of left ventricular mass in studies of 1988 to 2009 (n = 16), 15% (IQR: 9%-22%) in studies of 2010 to 2014 (n = 87), and 11% (IQR: 5%-19%) in studies of 2015 to 2019 (n = 150) (P = 0.031). The respective 5-year incidences of the composite of death, heart transplantation, left ventricular-assisted device implantation, or ventricular tachyarrhythmia were 40% (95% CI: 29%-51%), 32% (95% CI: 25%-39%), and 23% (95% CI: 16%-30%) (P = 0.002). The prognostic trend disappeared after adjustment for differences in the presenting phenotype.

Conclusions

Diagnoses of incident CS have increased exponentially in Finland. Concurrently, the phenotype has turned milder and prognosis better, suggesting detection of CS at an earlier stage of its course.

Comparison of prognosis in isolated versus systemic manifestations of cardiac sarcoidosis

BACKGROUND

Isolated cardiac sarcoidosis (iCS) is a poorly understood and under-recognised entity. Previous research has postulated that those with iCS have worsened outcomes compared to those with other manifestations of the disease, however, there have been studies which both support and refute this hypothesis.

PURPOSE OF REVIEW

This review will summarise the literature which focuses on differences in the epidemiology, imaging findings and patient outcome of those with isolated cardiac sarcoidosis (iCS) versus 'systemic' cardiac sarcoidosis (sCS) which is not isolated to the heart.

SUMMARY

Variations in study design make accurate comparison between current papers challenging, and that the factors which indicate poor prognosis in patients with iCS is not yet fully understood. Current literature suggests those with iCS are more likely to be male, have higher numbers of abnormal uptake patterns on cardiac imaging, and may have poorer prognosis than sCS patients. Multi-centre, prospective studies analysing isolated cardiac sarcoidosis across geographical regions are needed to improve our understanding of this phenomenon and ultimately improve patient outcome.

Characteristics and Outcomes of Hospitalized Patients With Heart Failure and Sarcoidosis: A Propensity-Matched Analysis of the Nationwide Readmissions Database 2010-2019

BACKGROUND

Sarcoidosis is associated with a poor prognosis. There is a lack of data examining the outcomes and readmission rates of sarcoidosis patients with heart failure (SwHF) and without heart failure (SwoHF). We aimed to compare the impact of non-ischemic heart failure on outcomes and readmissions in these two groups.

METHODS

The US Nationwide Readmission Database was queried from 2010 to 2019 for SwHF and SwoHF patients identified using the International Classification of Diseases, 9th and 10th Editions. Those with ischemic heart disease were excluded, and both cohorts were propensity matched for age, gender, and Charlson Comorbidity Index (CCI). Clinical characteristics, length of stay, adjusted healthcare-associated costs, 90-day readmission and mortality were analyzed.

RESULTS

We identified 97,961 hospitalized patients (median age 63 years, 37.9% male) with a diagnosis of sarcoidosis (35.9% SwHF vs 64.1% SwoHF). On index admission, heart failure patients had higher prevalences of atrioventricular block (3.3% vs 1.4%, P < .0001), ventricular tachycardia (6.5% vs 1.3%, P < .0001), ventricular fibrillation (0.4% vs 0.1%, P < .0001) and atrial fibrillation (22.1% vs 7.5%, P < .0001). SwHF patients were more likely to be readmitted (hazard ratio 1.28, P < .0001), had higher length of hospital stay (5 vs 4 days, P < .0001), adjusted healthcare-associated costs ($9,667.0 vs $9,087.1, P < .0001) and mortality rates on readmission (5.1% vs 3.8%, P < .0001). Predictors of mortality included heart failure, increasing age, male sex, higher CCI, and liver disease.

CONCLUSION

SwHF is associated with higher rates of arrhythmia at index admission, as well as greater hospital cost, readmission and mortality rates compared to those without heart failure.

Immunomodulating and Immunosuppressive Therapy for Virus-Negative Immune-Mediated Myocarditis

Myocarditis is an inflammatory disease of the myocardium caused by infectious and noninfectious agents. Clinical manifestations range from mildly symptomatic forms to acute heart failure, cardiogenic shock, life-threatening arrhythmias and sudden death. Myocarditis is still a challenging diagnosis because of its wide variability in clinical presentation and unpredictable course. Moreover, a standardized, specific treatment in not yet available. Immunosuppressive treatment for virus-negative lymphocytic myocarditis is still controversial. Conversely, immunosuppression is well established in sarcoidosis, eosinophilic, giant-cell, drug hypersensitivity, and trauma-related myocarditis as well as lymphocytic myocarditis associated with connective tissue diseases or with the rejection of a transplanted heart. Recently, immunosuppressive therapy has been also recognized as an effective treatment in virus-negative inflammatory cardiomyopathy. The aim of this review is to underline the role of immunomodulating and immunosuppressive therapies in patients with immune-mediated myocarditis and illustrate the different treatment strategies depending on the etiology. An endomyocardial biopsy remains the gold standard for the diagnosis of myocarditis as well as for a tailored treatment.

Arrhythmias in Cardiac Sarcoidosis: Management and Prognostic Implications

Cardiac sarcoidosis (CS) is characterized by various arrhythmic manifestations ranging from catastrophic sudden cardiac death secondary to ventricular arrhythmia, severe conduction disease, sinus node dysfunction, and atrial fibrillation. The management of CS is complex and includes not only addressing the arrhythmia but also controlling the myocardial inflammation resultant from the autoimmune reaction. Arrhythmic manifestations of CS carry significant prognostic implications and invariably affect long-term survival in these patients. In this review, we focus on management of arrhythmic manifestation of cardiac sarcoidosis as well as risk stratification for sudden cardiac death in these patients.

Diagnostic and management strategies in cardiac sarcoidosis

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

The role of ICDs in patients with sarcoidosis-A comprehensive review

BACKGROUND

Implantable cardioverter defibrillator (ICD) use in cardiac sarcoidosis (CS) to prevent sudden cardiac death (SCD) is a potentially life-saving intervention. However, the factors that determine outcome in this cohort remains largely unknown. This review analyses CS patients with an ICD and highlights determinants of poor outcome.

OUTCOMES

Analysis of studies which used the 2014 HRS Consensus, 2017 AHA/ACC/HRS Guideline and 2022 ESC Guidelines showed that those with class I recommendations have higher incidences of ventricular arrhythmia (VA) than those with class II recommendations. Additionally, even those with normal left ventricular ejection fraction (LVEF) and CS are at high risk of VA and SCD.

SUMMARY

Compounding research emphasises the importance of cardiac imaging in those with sarcoidosis, with evidence to suggest a possible need for revision of the guidelines. Other variables such as demographics and ventricular characteristics may prove useful in predicting those to benefit most from ICD insertion.

Multiparametric Mapping via Cardiovascular Magnetic Resonance in the Risk Stratification of Ventricular Arrhythmias and Sudden Cardiac Death

Risk stratification for malignant ventricular arrhythmias and sudden cardiac death is a daunting task for physicians in daily practice. Multiparametric mapping sequences obtained via cardiovascular magnetic resonance imaging can improve the risk stratification for malignant ventricular arrhythmias by unveiling the presence of pathophysiological pro-arrhythmogenic processes. However, their employment in clinical practice is still restricted. The present review explores the current evidence supporting the association between mapping abnormalities and the risk of ventricular arrhythmias in several cardiovascular diseases. The key message is that further clinical studies are needed to test the additional value of mapping techniques beyond conventional cardiovascular magnetic resonance imaging for selecting patients eligible for an implantable cardioverter defibrillator.

Arrhythmic manifestations and outcomes of definite and probable cardiac sarcoidosis

BACKGROUND

The 2014 Heart Rhythm Society consensus statement defines histological (definite) and clinical (probable) diagnostic categories of cardiac sarcoidosis (CS), but few studies have compared their arrhythmic phenotypes and outcomes.

OBJECTIVE

The purpose of this study was to evaluate the electrophysiological/arrhythmic phenotype and outcomes of patients with definite and probable CS.

METHODS

We analyzed the arrhythmic/electrophysiological phenotype in a single-center North American cohort of 388 patients (median age 56 years; 39% female, n = 151) diagnosed with definite (n = 58) or probable (n = 330) CS (2000-2022). The primary composite outcome was survival to first ventricular tachycardia/fibrillation (VT/VF) event or sudden cardiac death. Key secondary outcomes were also assessed.

RESULTS

At index evaluation, in situ cardiac implantable electronic devices and antiarrhythmic drug use were more common in definite CS. At a median follow-up of 3.1 years, the primary outcome occurred in 22 patients with definite CS (38%) and 127 patients with probable CS (38%) (log-rank, P = .55). In multivariable analysis, only a higher ratio of the 18F-fluorodeoxyglucose maximum standardized uptake value of the myocardium to the maximum standardized uptake value of the blood pool (hazard ratio 1.09; 95% confidence interval 1.03-1.15; P = .003, per 1 unit increase) was associated with the primary outcome. During follow-up, patients with definite CS had a higher burden of device-treated VT/VF events (mean 2.86 events per patient-year vs 1.56 events per patient-year) and a higher rate of progression to heart transplant/left ventricular assist device implantation but no difference in all-cause mortality compared with patients with probable CS.

CONCLUSION

Patients with definite and probable CS had similarly high risks of first sustained VT/VF/sudden cardiac death and all-cause mortality, though patients with definite CS had a higher overall arrhythmia burden. Both CS diagnostic groups as defined by the 2014 Heart Rhythm Society criteria require an aggressive approach to prevent arrhythmic complications.

Diagnostics, treatment and outcomes of cardiac sarcoidosis in a Norwegian cohort

BACKGROUND

Evidence-based guidelines for cardiac sarcoidosis (CS) regarding use of second- and third-line agents, treatment duration, surveillance and prognostic factors are lacking.

OBJECTIVE

To analyze the clinical presentation, diagnostics, treatment, monitoring and clinical outcomes in a Norwegian cohort.

METHODS

Using discharge diagnoses between 2017 through 2020 from a large tertiary center, we identified 52 patients with CS. We performed a systematic chart review following a pre-specified checklist. The primary outcome of major cardiovascular events (MACE) was defined as a composite of cardiovascular hospitalization, defibrillator therapy, cardiac transplantation, or death.

RESULTS

18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed pathological tracer uptake in 35/36 (97%) of immunosuppression-naïve patients. Immunosuppressive treatment was administered to 49/52 patients (94%) for a median of 43 (IQR 34) months; 69% were treated with second-line (methotrexate, azathioprine, mycophenolate mofetil) and 25% with third-line (rituximab, infliximab) agents, respectively. Rituximab reduced inflammation as assessed by interval FDG-PET imaging and was overall well tolerated. Median duration to first MACE was 6 (IQR 10) months and 17/23 patients (74%) experienced a MACE within 12 months from CS diagnosis. No mortality was recorded and 20% achieved full remission. Age below the median of 53 years at time of diagnosis was associated with an increased risk of a MACE.

CONCLUSION

Long-term immunosuppression including a liberal use of non-steroidal agents, appeared essential in treating CS. Although the burden of cardiovascular events was substantial, the survival was excellent in this contemporary cohort. Prospective randomized studies are urgently needed to define the best therapy for these patients.

Screening tools for the detection of clinically silent cardiac sarcoidosis

BACKGROUND

clinically silent cardiac sarcoidosis (CS) may be associated with adverse outcomes, hence the rationale for screening patients with extracardiac sarcoidosis. The optimal screening strategy has not been clearly defined.

METHODS

patients with extra-cardiac sarcoidosis were prospectively included and underwent screening consisting of symptom history, electrocardiography (ECG), transthoracic echocardiogram, Holter, and signal-averaged ECG (SAECG). Cardiac magnetic resonance (CMR) was performed in all patients. Clinically silent CS was defined as CMR demonstrating late gadolinium enhancement (LGE) in a pattern compatible with CS according to a majority of independent and blinded CMR experts. Significant cardiac involvement was defined as the presence of LGE ≥6% and/or a positive fluorodeoxyglucose-positron emission tomography.

RESULTS

among the 129 patients included, clinically silent CS was diagnosed in 29/129 (22.5%), and 19/129 patients (14.7%) were classified as CS with significant cardiac involvement. There was a strong association between hypertension and CS (p < 0.05). Individual screening tools provided low diagnostic yield; however, combination of tests performed better, for example, a normal Holter and a normal SAECG had negative predictive values of 91.7%. We found consistently better diagnostic accuracy for the detection of CS with significant cardiac involvement.

CONCLUSION

clinically silent CS and CS with significant cardiac involvement were found in 22.5% and 14.7% of patients with extra-cardiac sarcoidosis. The association with hypertension raises the possibility that some cases of hypertensive cardiomyopathy may be mistaken for CS. Screening with readily available tools, for example Holter and SAECG, may help identifying patients without CS where additional CMR is not needed.

Relationship of Mild to Moderate Impairment of Left Ventricular Ejection Fraction With Fatal Ventricular Arrhythmic Events in Cardiac Sarcoidosis

BACKGROUND

Current guidelines recommend placing an implantable cardiac defibrillator for patients with cardiac sarcoidosis and a severely impaired left ventricular ejection fraction (LVEF) of ≤35%. In this study, we determined the association between mild or moderate LVEF impairment and fatal ventricular arrhythmic event (FVAE).

METHODS AND RESULTS

We retrospectively analyzed 401 patients with cardiac sarcoidosis without sustained ventricular arrhythmia at diagnosis. The primary end point was an FVAE, defined as the combined endpoint of documented ventricular tachycardia or ventricular fibrillation and sudden cardiac death. Two cutoff points for LVEF were used: a sex-specific lower threshold of normal range of LVEF (52% for men and 54% for women) and an LVEF of 35%, which is used in the current guidelines. During a median follow-up of 3.2 years, 58 FVAEs were observed, and the 5- and 10-year estimated incidences of FVAEs were 16.8% and 23.0%, respectively. All patients were classified into 3 groups according to LVEF: impaired LVEF group, mild to moderate impairment of LVEF group, and maintained LVEF group. Multivariable competing risk analysis showed that both the impaired LVEF group (hazard ratio [HR], 3.24 [95% CI, 1.49-7.04]) and the mild to moderate impairment of LVEF group (HR, 2.16 [95% CI, 1.04-4.46]) were associated with a higher incidence of FVAEs than the maintained LVEF group after adjustment for covariates.

CONCLUSIONS

Patients with cardiac sarcoidosis are at a high risk of FVAEs, regardless of documented ventricular arrhythmia at the time of diagnosis. In patients with cardiac sarcoidosis, mild to moderate impairment of LVEF is associated with FVAEs.

Cardiac sarcoidosis with extensive and heterogeneous left ventricular FDG uptake in absence of guidelines indication for an implantable defibrillator: Ventricular tachycardia precipitated by immunosuppressive therapy, should we have done differently?

A 40-year-old man, newly diagnosed with cardiac sarcoidosis (CS) presented with symptomatic ventricular tachycardia three days after starting steroid-based immunosuppressive therapy (IT). There was no clear guideline indication for implantable cardioverter-defibrillator (ICD) before the initiation of IT. Shortly after ICD implantation and the initiation of anti-arrhythmic drugs, recurring ventricular arrhythmias required titration of the anti-arrhythmic drug therapy. One-year follow-up assessment showed no significant arrhythmias and complete PET scan FDG uptake suppression. This case, along with recent publications, suggests transient pro-arrhythmic effects of steroids in patients with CS, which are not appropriately addressed in the current guidelines. We believe ICD implantation should be considered in clinically manifest CS before initiating IT, particularly in cases with heterogeneous and/or extensive FDG uptake on PET scans.

Peri-Operative Outcomes Associated With the Placement of Implantable Cardioverter-Defibrillators in Patients With Sarcoidosis: A Nationwide Database Analysis

Rationale Sarcoidosis with cardiac involvement can be associated with serious life-threatening arrhythmias and an increased risk of sudden cardiac death. Implantable cardiac defibrillators (ICDs) have been used for primary and secondary prevention of sudden death in patients with cardiac sarcoidosis (CS). Post-ICD placement complications have been shown to be higher in patients with CS. However, data comparing postoperative ICD complications among sarcoidosis patients with the general population is limited. Here, we evaluated the association of postoperative complications with implantable cardioverter-defibrillators in sarcoidosis.  Methods Using the NIS database, we identified cases of adults aged ≥ 18 years undergoing surgical placement of implantable cardioverter-defibrillators between 2010 and 2019. Using ICD-9 and ICD-10 codes, we identified patients with sarcoidosis. In all statistical analyses, we applied weights provided by HCUP to produce results representative of national estimates. We compared categorical and continuous covariates in the baseline characteristics using the chi-square test and analysis of variance, respectively. We employed multivariable logistic and linear regression to compare binomial and continuous outcomes to assess differences in mortality rates. Results We analyzed 114073 patients during the study period. Of these, 1012 (0.9%) had sarcoidosis and were found to be significantly younger and female compared to patients without sarcoidosis (56.4 ±11.5 years vs. 65.6 ± 13.9 years, p <0.001) and (39.4% vs. 28.3%, p<0.001) respectively. Further, patients with sarcoidosis were more likely to be African American (45% vs. 16.3%), have private insurance (45.4% vs. 23.8%), and less likely to have Medicare (34.9% vs. 60.9%). Overall, post-ICD placement complications such as lead complications (4.2% vs. 6.9%, p = 0.03), post-procedure hemorrhage (4.1% vs. 5.5%, p=0.048), and requirement for transfusion (2.3% vs. 4.4%) were less likely in patients with sarcoidosis. Regarding post-ICD placement inpatient mortality, sarcoidosis was not associated with any difference (OR: 0.71, 95% CI 0.18-2.88 p=0.634). Conclusions Placement of implantable cardioverter-defibrillators in patients with sarcoidosis is a safe procedure and is associated with significantly lower rates of lead complications, post-procedure hemorrhage, and requirement for transfusion. This is of great importance as it is known that patients with underlying sarcoidosis are predisposed to developing more cardiac complications.

Improved outcomes of cardiac resynchronization therapy with a defibrillator in systolic heart failure: Analysis of the Japan cardiac device treatment registry database

Background

Temporal change in outcomes of heart failure patients receiving cardiac resynchronization therapy with a defibrillator (CRT-D) is unknown.

Methods

We assess outcomes and underlying heart diseases of patients receiving CRT-D with analyzing database of the Japan cardiac device treatment registry (JCDTR) at the implantation year 2011-2015 and New JCDTR at the implantation year 2018-2021.

Results

Proportion of nonischemic heart diseases was about 70% in both the groups (JCDTR: 69%; New JCDTR: 72%). Cardiac sarcoidosis increased with the rate of 5% in the JCDTR to 9% in the New JCDTR group. During an average follow-up of 21 months, death from any cause occurred in 167 of 906 patients in the JCDTR group (18%) and 79 of 611 patients in the New JCDTR group (13%) (adjusted hazard ratio [aHR] in the New JCDTR group, 0.72; 95% confidence interval [CI]: 0.55-0.94; p = .017). The superiority was mainly driven by reduction in the risk of noncardiac death. With regard to appropriate and inappropriate implantable cardioverter-defibrillator (ICD) therapy, there was a significant reduction in the New JCDTR group versus the JCDTR group (aHR in the New JCDTR group, 0.76; 95% CI: 0.59-0.98; p = .032 for appropriate ICD therapy; aHR in the New JCDTR group, 0.24; 95% CI: 0.12-0.50; p < .0001 for inappropriate ICD therapy).

Conclusions

All-cause mortality was reduced in CRT-D patients implanted during 2018-2021 compared to those during 2011-2015, with a significant reduction in noncardiac death.

Cardiac Sarcoidosis: A Comprehensive Clinical Review

Sarcoidosis is an inflammatory multisystemic disease of unknown etiology characterized by the formation of non-caseating granulomas. Sarcoidosis can affect any organ, predominantly the lungs, lymphatic system, skin and eyes. While > 90% of patients with sarcoidosis have lung involvement, an estimated 5% of patients with sarcoidosis have clinically manifest cardiac sarcoidosis (CS), whereas approximately 25% have asymptomatic, clinically silent cardiac involvement verified by autopsy or imaging studies. CS can present with conduction disturbances, ventricular arrhythmias, heart failure or sudden cardiac death. Approximately 30% of < 60-year-old patients presenting with unexplained high degree atrioventricular (AV) block or ventricular tachycardia are diagnosed with CS, therefore CS should be strongly considered in such patients. CS is the second leading cause of death among patients affected by sarcoidosis after pulmonary sarcoidosis, therefore its early recognition is important, because early treatment may prevent death from cardiovascular involvement. The establishment of isolated CS diagnosis sometimes can be quite difficult, when extracardiac disease cannot be verified. The other reason for the difficulty to diagnose CS is that CS is a chameleon of cardiology and it can mimic (completely or almost completely) different cardiac diseases, such as arrhythmogenic cardiomyopathy, giant cell myocarditis, dilated, restrictive and hypertrophic cardiomyopathies. In this review article we will discuss the current diagnosis and management of CS and delineate the potential difficulties and pitfalls of establishing the diagnosis in atypical cases of isolated CS.

Sarcoid heart disease and imaging

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

Clinical characteristics and prognosis of patients with isolated cardiac sarcoidosis: Insights from the ILLUMINATE-CS study

AIM

Data on the clinical features and prognosis of patients with isolated cardiac sarcoidosis (iCS) are limited. This study evaluated the clinical characteristics and prognostic impact of iCS.

METHODS AND RESULTS

This was a secondary analysis of the ILLUMINATE-CS study, a multicentre, retrospective registry investigating the clinical characteristics and prognosis of cardiac sarcoidosis. iCS was diagnosed according to the 2016 Japanese Circulation Society (JCS) guidelines. Clinical characteristics and prognosis were compared between patients with iCS and systemic cardiac sarcoidosis (sCS). The primary outcome was a combined endpoint of all-cause death, hospitalization for heart failure, or fatal ventricular arrhythmia events. Among 475 patients with CS (mean age, 62.0 ± 10.9 years; female ratio, 59%) diagnosed by the JCS guidelines, 119 (25.1%) were diagnosed with iCS. Patients with iCS had a higher prevalence of a history of atrial fibrillation or hospitalization for heart failure, or lower left ventricular ejection fraction than those with sCS. During a median follow-up of 42.3 (interquartile range, 22.8-72.5) months, 141 primary outcomes (29.7%) occurred. Cox proportional hazard analysis revealed that iCS was a significant risk factor for the primary outcome in the unadjusted model (hazard ratio [HR] 1.62; 95% confidence interval [CI] 1.12-2.34; p = 0.011). However, this association was not retained after adjustment for other covariates (adjusted HR 1.27; 95% CI 0.86-1.88; p = 0.226).

CONCLUSIONS

Patients with iCS had more impaired cardiovascular function at the time of diagnosis than those with sCS. However, iCS was not independently associated with poor prognosis after adjustment for prognostic factors.

State-of-the-art document on optimal contemporary management of cardiomyopathies

Cardiomyopathies represent significant contributors to cardiovascular morbidity and mortality. Over the past decades, a progress has occurred in characterization of the genetic background and major pathophysiological mechanisms, which has been incorporated into a more nuanced diagnostic approach and risk stratification. Furthermore, medications targeting core disease processes and/or their downstream adverse effects have been introduced for several cardiomyopathies. Combined with standard care and prevention of sudden cardiac death, these novel and emerging targeted therapies offer a possibility of improving the outcomes in several cardiomyopathies. Therefore, the aim of this document is to summarize practical approaches to the treatment of cardiomyopathies, which includes the evidence-based novel therapeutic concepts and established principles of care, tailored to the individual patient aetiology and clinical presentation of the cardiomyopathy. The scope of the document encompasses contemporary treatment of dilated, hypertrophic, restrictive and arrhythmogenic cardiomyopathy. It was based on an expert consensus reached at the Heart Failure Association online Workshop, held on 18 March 2021.

Phenotyping heart failure by nuclear imaging of myocardial perfusion, metabolism, and molecular targets

Nuclear imaging techniques can detect and quantify pathophysiological processes underlying heart failure, complementing evaluation of cardiac structure and function with other imaging modalities. Combined imaging of myocardial perfusion and metabolism can identify left ventricle dysfunction caused by myocardial ischaemia that may be reversible after revascularization in the presence of viable myocardium. High sensitivity of nuclear imaging to detect targeted tracers has enabled assessment of various cellular and subcellular mechanisms of heart failure. Nuclear imaging of active inflammation and amyloid deposition is incorporated into clinical management algorithms of cardiac sarcoidosis and amyloidosis. Innervation imaging has well-documented prognostic value with respect to heart failure progression and arrhythmias. Emerging tracers specific for inflammation and myocardial fibrotic activity are in earlier stages of development but have demonstrated potential value in early characterization of the response to myocardial injury and prediction of adverse left ventricular remodelling. Early detection of disease activity is a key for transition from broad medical treatment of clinically overt heart failure towards a personalized approach aimed at supporting repair and preventing progressive failure. This review outlines the current status of nuclear imaging in phenotyping heart failure and combines it with discussion on novel developments.

An International Survey of Current Clinical Practice in the Treatment of Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) is a potentially serious form of infiltrative cardiomyopathy. Despite scarce evidence, immunosuppressive treatment is generally recommended, but local routines may vary significantly. We sought to survey the clinical practices in the treatment of CS, with the aim that the results may suggest future research priorities. We conducted a web-based survey focused on treatment-naive patients with CS. We subclassified CS according to the presence/absence of overt cardiac presentation (clinically manifest/silent) and to the presence/absence of active inflammation (metabolically active/inactive by fluorodeoxyglucose positron emission tomography). The survey was developed jointly by the authors and administered to expert clinicians (n = 79) involved in CS treatment. An agreement threshold was set at 70%. A total of 62 of 79 respondents (78.5%) from 12 countries completed the survey. The agreement threshold was reached for: (1) always treating clinically manifest, metabolically active CS, 57 of 62 (91.9%), (2) never treating clinically silent, metabolically inactive CS, 44 of 62 (71.0%), (3) not requiring histopathologic confirmation of sarcoidosis before treatment initiation, (49 of 62, 79.0%), (4) using fluorodeoxyglucose positron emission tomography for assessing treatment indication (44 of 62, 71.0%) and treatment response (44 of 62, 71.0%), and (5) using prednisone as a first-line agent (100%), although respondents were divided on monotherapy (69.4%) or combination with methotrexate 25.8%. The approach to particular scenarios, tapering, and duration of treatment showed the greatest variation in response. In conclusion, in this survey of clinical practice, important aspects of CS treatment reached the agreement threshold, whereas others showed a great degree of clinical equipoise.

Sex differences in clinical characteristics and prognosis of patients with cardiac sarcoidosis

OBJECTIVE

Owing to the paucity of data, this study aimed to investigate sex differences in clinical features and prognosis of patients with cardiac sarcoidosis (CS).

METHODS

This study was a secondary analysis of the ILLUstration of the Management and prognosIs of JapaNese PATiEnts with Cardiac Sarcoidosis registry-a retrospective multicentre registry that enrolled patients with CS between 2001 and 2017. The primary outcome was potentially fatal ventricular arrhythmia events (pFVAEs)-a composite of sudden cardiac death, sustained ventricular tachycardia lasting >30 s, ventricular fibrillation or the requirement for implantable cardioverter defibrillator therapy.

RESULTS

Of the 512 participants (mean age±SD 61.6±11.4 years), 329 (64.2%) were females. Both sexes had peak ages of 60-64 years at diagnosis. Male patients were younger and had a higher prevalence of coronary artery disease and lower left ventricular ejection fraction than female patients. During a median follow-up of 3 years (IQR 1.6-5.6), pFVAEs were observed in 99 patients, with males having a significantly higher risk than females (p=0.002). This association was retained even after adjustment for other risk factors for pFVAEs, including left ventricular ejection fraction (adjusted HR 1.80; 95% CI 1.08 to 3.01, p=0.025).

CONCLUSION

Approximately two-thirds of patients with CS were females, with a peak age of approximately 60 years at clinical diagnosis in both sexes; male patients were younger than female patients. Male patients had a significantly higher risk of pFVAEs than female patients.

TRIAL REGISTRATION NUMBER

UMIN000034974.

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.

Diagnosis of cardiac sarcoidosis: histological evidence vs. imaging

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Prognostic Implications of Sarcoidosis Granulomas - Insights From the Multicenter Registry, the Japanese Cardiac Sarcoidosis Prognostic Study

Background: Definitions of cardiac sarcoidosis (CS) differ among guidelines. Any systemic histological finding of CS is essential for the diagnosis of CS in the 2014 Heart Rhythm Society statement, but not necessary in the Japanese Circulation Society 2016 guidelines. This study aimed to reveal the differences in outcomes by comparing 2 groups, namely CS patients with or without systemic histologically proven granuloma. Methods and Results: This study retrospectively included 231 consecutive patients with CS. CS with granulomas in ≥1 organs was diagnosed in 131 patients (Group G), whereas CS without any granulomas was diagnosed in the remaining 100 patients (Group NG). Left ventricular ejection fraction (LVEF) was significantly reduced in Group NG compared with Group G (44±13% vs. 50±16%, respectively; P=0.001). However, Kaplan-Meier curves showed that major adverse cardiovascular events (MACE)-free survival outcomes were comparable between the 2 groups (log-rank P=0.167). Univariable analyses showed that significant predictors of MACE were Groups G/NG, histological CS, LVEF, and high B-type natriuretic peptide (BNP) or N-terminal pro BNP concentrations, but none of these was significant in multivariable analyses. Conclusions: Overall risks of MACE were similar between the 2 groups despite different manifestations in cardiac dysfunction. The data not only validate the prognostic value of non-invasive diagnosis of CS, but also show the need for careful observation and therapeutic strategy in patients with CS without any granuloma.

Preventing Deadly Complications of Cardiac Sarcoidosis

Cardiac sarcoidosis is a rare complication of pulmonary sarcoidosis, causing granulomatous inflammation of the myocardium, ultimately resulting in infiltrative cardiomyopathy. Through fibrotic inflammation, cardiac sarcoidosis predisposes patients to multiple complications, such as conduction abnormalities, ventricular arrhythmias, heart failure, and sudden cardiac death. Due to the adverse prognosis of conduction abnormalities in these patients, dual chamber implantable cardiac defibrillator (ICD) therapy is beneficial in reducing mortality and morbidity. Early ICD placement can prevent further immune-driven fibrotic conduction complications. Here we present a case of a 50-year-old female who underwent ICD placement due to conduction abnormalities secondary to cardiac sarcoidosis.

Management of the arrhythmic manifestations of cardiac sarcoidosis

Cardiac sarcoidosis (CS) is characterised by a high burden of arrhythmic manifestations and cardiac electrophysiologists play an important role in both the diagnosis and management of this challenging condition. CS is characterised by the formation of noncaseating granulomas within the myocardium, which can subsequently lead to fibrosis. Clinical presentations of CS are varied and depend on the location and extent of granulomas. Patients may present with atrioventricular block, ventricular arrhythmias, sudden cardiac death or heart failure. CS is being increasing diagnosed through use of advanced cardiac imaging, however endomyocardial biopsy is often still required to confirm the diagnosis. Due to the low sensitivity of fluoroscopy-guided right ventricular biopsies, three-dimensional electro-anatomical mapping and electrogram-guided biopsies are being investigated as a means to improve diagnostic yield. Cardiac implantable electronic devices are often required in the management of CS, either for pacing or for primary or secondary prevention of ventricular arrhythmias. Catheter ablation for ventricular arrythmias may also be required, although this is often associated with high recurrence rates due to the challenging nature of the arrhythmogenic substrate. This review will explore the underlying mechanisms of the arrhythmic manifestations of CS, provide an overview of current clinical practice guidelines, and examine the important role that cardiac electrophysiologists play in managing patients with CS.

Pathophysiological Gaps, Diagnostic Challenges, and Uncertainties in Cardiac Sarcoidosis

Cardiac sarcoidosis can mimic any cardiomyopathy in different stages. Noncaseating granulomatous inflammation can be missed, because of the nonhomogeneous distribution in the heart. The current diagnostic criteria show discrepancies and are partly nonspecific and insensitive. Besides the diagnostic pitfalls, there are controversies in the understanding of the causes, genetic and environmental background, and the natural evolution of the disease. Here, we review the current pathophysiological aspects and gaps that are relevant for future cardiac sarcoidosis diagnostics and research.

Palpitations and Shortness of Breath-Just a "Bump in the Road" or Something More?

A previously healthy person in their 60s with progressive shortness of breath and fatigue for the past 6 months presented to the emergency department with palpitations and shortness of breath. What is your diagnosis?

Diagnosis and Treatment of Cardiac Sarcoidosis

About 5% of sarcoidosis patients develop clinically manifest cardiac features. Cardiac sarcoidosis (CS) typically presents with conduction abnormalities, ventricular arrhythmias and heart failure. Its diagnosis is challenging and requires a substantial degree of clinical suspicion as well as expertise in advanced cardiac imaging. Adverse events, particularly malignant arrhythmias and development of heart failure, are common among CS patients. A timely diagnosis is paramount to ameliorating outcomes for these patients. Despite weak evidence, immunosuppression (primarily with corticosteroids) is generally recommended in the presence of active inflammation in the myocardium. The burden of malignant arrhythmias remains important regardless of treatment, thus leading to the recommended use of an implantable cardioverter defibrillator in most patients with clinically manifest CS.