Treatment with corticosteroids is associated with an increase in ventricular arrhythmia burden in patients with clinically manifest cardiac sarcoidosis: Insights from implantable cardioverter-defibrillator diagnostics

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.

Cardiac GR Mediates the Diurnal Rhythm in Ventricular Arrhythmia Susceptibility

BACKGROUND

Ventricular arrhythmias (VAs) demonstrate a prominent day-night rhythm, commonly presenting in the morning. Transcriptional rhythms in cardiac ion channels accompany this phenomenon, but their role in the morning vulnerability to VAs and the underlying mechanisms are not understood. We investigated the recruitment of transcription factors that underpins transcriptional rhythms in ion channels and assessed whether this mechanism was pertinent to the heart's intrinsic diurnal susceptibility to VA.

METHODS AND RESULTS

Assay for transposase-accessible chromatin with sequencing performed in mouse ventricular myocyte nuclei at the beginning of the animals' inactive (ZT0) and active (ZT12) periods revealed differentially accessible chromatin sites annotating to rhythmically transcribed ion channels and distinct transcription factor binding motifs in these regions. Notably, motif enrichment for the glucocorticoid receptor (GR; transcriptional effector of corticosteroid signaling) in open chromatin profiles at ZT12 was observed, in line with the well-recognized ZT12 peak in circulating corticosteroids. Molecular, electrophysiological, and in silico biophysically-detailed modeling approaches demonstrated GR-mediated transcriptional control of ion channels (including Scn5a underlying the cardiac Na+ current, Kcnh2 underlying the rapid delayed rectifier K+ current, and Gja1 responsible for electrical coupling) and their contribution to the day-night rhythm in the vulnerability to VA. Strikingly, both pharmacological block of GR and cardiomyocyte-specific genetic knockout of GR blunted or abolished ion channel expression rhythms and abolished the ZT12 susceptibility to pacing-induced VA in isolated hearts.

CONCLUSIONS

Our study registers a day-night rhythm in chromatin accessibility that accompanies diurnal cycles in ventricular myocytes. Our approaches directly implicate the cardiac GR in the myocyte excitability rhythm and mechanistically link the ZT12 surge in glucocorticoids to intrinsic VA propensity at this time.

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.

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.

Multi-modal treatment in a pregnant woman with untreated cardiac sarcoidosis complicated by cardiac dysfunction and ventricular arrhythmias: a case report and literature review

Background

The treatment of cardiac sarcoidosis during pregnancy is inherently challenging owing to its impact on the foetus.

Case summary

We report a case of a 30-year-old pregnant woman with untreated cardiac sarcoidosis. One year prior to admission, she underwent permanent pacemaker implantation for complete atrioventricular block. Left ventricular ejection fraction (EF) showed a declining trend, and ventricular tachycardia (VT) was documented. Following an extensive evaluation, the patient was diagnosed with active cardiac sarcoidosis, and the pregnancy was detected at the same time. Considering the high risk of mortality and cardiovascular complications in pregnant patients with decreased EF and VT, we meticulously discussed the optimal timing of multi-modal treatment, including bisoprolol, eplerenone, sotalol, and prednisolone and cardiac resynchronization therapy with a defibrillator, and its effect on the foetus. These interventions improved the EF to 49%, and the baby was successfully delivered without adverse events or neonatal complications developing. At 8 months' post-partum, the mother and the baby were doing well, and the EF was 45%.

Discussion

Cardiac sarcoidosis can lead to adverse outcomes for both the mother and the foetus. However, with multi-modal treatment individually optimized and implemented by a multi-disciplinary team of specialists in each field, even pregnant women with untreated cardiac sarcoidosis who present with reduced EF and VT can achieve safe childbirth.

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.

Cardiac sarcoidosis

The diagnostic yield of endomyocardial biopsy in cardiac sarcoidosis (CS) is quite low because of the patchy involvement, and for the diagnosis of CS, existing guidelines required histological confirmation. Therefore, especially for isolated CS, diagnosis consistent with the guidelines cannot be made in a large number of patients. With recent developments in imaging modalities such as cardiac magnetic resonance and 18-fluorodeoxyglucose positron emission tomography, diagnosing CS has become easier and diagnostic criteria for CS not compulsorily requiring histological confirmation have been suggested. Despite significant advances in diagnostic tools, large-scale studies that can guide treatment plans are still lacking, and treatment has relied on the experience accumulated over the past years and the consensus of experts. However, opinions vary, depending on the situation, which is quite puzzling for the physician treating CS. Moreover, with the advent of new immunosuppressant agents, these new drugs have been applied under the assumption that the effect of immunosuppression is not much different from that of other well-known autoimmune diseases that require immunosuppression. However, we should wait to see the beneficial effects of these new immunosuppressants before we attempt to apply these agents in our clinical practice. This review summarises the widely used diagnostic criteria, current diagnostic modalities and recommended treatments for sarcoidosis. We have added our opinions on selecting or modifying diagnostic and treatment plans from the diverse current recommendations.

FDG PET/CT Imaging of Sarcoidosis

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

Successful use of stellate ganglion phototherapy in refractory ventricular tachycardia in a patient with cardiac sarcoidosis

Ventricular arrhythmias are a life-threatening factor in cardiac sarcoidosis (CS), posing a significant therapeutic challenge. Stellate ganglion phototherapy (SGP), a non-invasive procedure for modification of the sympathetic nervous system, is an effective treatment for refractory ventricular tachycardia (RVT). However, there are limited data on the efficacy of SGP for RVT in patients with CS. In our case report, we found that SGP was effective for treating RVT in a patient with CS.

We present the case of a man in his 60s with multiple cardioversions of implantable cardioverter defibrillator for ventricular tachycardia. The patient was administered prednisolone for the management of CS, which subsequently led to an increase in anti-tachycardia pacing for ventricular tachycardias. We introduced SGP to suppress RVT and anti-tachycardia pacing decreased from 371 to 25 events. Thus, SGP could be a feasible option for the management of RVT in patients with CS.

What cardiologists should know about cardiac sarcoidosis in 2022?

PURPOSE OF REVIEW

Cardiac sarcoidosis (CS) is a potentially fatal condition when unrecognized or not treated adequately. The purpose of this review is to provide new strategies to increase clinical recognition of CS and to present an updated overview of the immunosuppressive treatments using most recent data published in the last 18 months.

RECENT FINDINGS

CS is an increasingly recognized pathology, and its diagnostic is made 20 times more often in the last two decades. Recent studies have shown that imaging alone usually lacks specificity to distinguish CS from other inflammatory cardiomyopathies. However, imaging can be used to increase significantly diagnostic yield of extracardiac and cardiac biopsy. Recent reviews have also demonstrated that nearly 25% of patients will be refractory to standard treatment with prednisone and that combined treatment with a corticosteroid-sparing agent is often necessary for a period that remains undetermined.

SUMMARY

CS is a complex pathology that should always require a biopsy attempt to have a histological proven diagnosis before starting immunosuppressive therapy consisting of corticosteroids with or without a corticosteroid-sparing agent.

Corticosteroid and Immunosuppressant Therapy for Cardiac Sarcoidosis: A Systematic Review

Background Corticosteroid therapy for the treatment of clinically manifest cardiac sarcoidosis is generally recommended. Our group previously systematically reviewed the data in 2013; since then, there has been increasing quality and quantity of data and also interest in nonsteroid agents. Methods and Results Studies were identified from MEDLINE, EMBASE, Cochrane Controlled Trials Register, Cochrane Database of Systematic Reviews, and the National Institutes of Health ClinicalTrials.gov database. The quality of included articles was rated using Scottish Intercollegiate Guidelines Network 50. Outcomes examined were atrioventricular conduction, left ventricular function, ventricular arrhythmias, and mortality. A total of 3527 references were retrieved, and 34 publications met the inclusion criteria. There were no randomized trials, and only 2 studies were rated good quality. In the 34 reports (total of 1297 patients), 1125 patients received corticosteroids, 235 received additional or other immunosuppressant therapy, and 97 patients received no therapy. There were 178 patients treated for atrioventricular conduction disease, with 76/178 (42.7%) improving. In contrast, 21 patients were not treated with corticosteroids and/or immunosuppressant therapy, and none of them improved. Therapy was associated with the prevention of deterioration in left ventricular function. A total of 8 publications reported on ventricular arrhythmia burden, and 19 reported on mortality; the data quality was too limited to draw conclusions for the latter 2 outcomes. Conclusions The best quality data relate to atrioventricular nodal conduction and left ventricular function recovery. In both situations, therapy with corticosteroids and/or immunosuppressant therapy were sometimes associated with positive outcomes. The data quality is too limited to draw conclusions for ventricular arrhythmias and mortality.

Management of ventricular tachycardia in patients with cardiac sarcoidosis

Sarcoidosis is a multisystem granulomatous disease with 2 different phases (inflammation and scar). In the current era of targeted use of implantable cardioverter-defibrillators and modern heart failure therapy, recent data indicate the prognosis of cardiac sarcoidosis (CS) is much improved, and hence more patients are presenting with recurrent ventricular tachycardia (VT). This review highlights our current understanding of the pathophysiology and management of ventricular arrhythmias in CS with the major focus on indications, techniques, and outcomes of ablation. It is likely macroreentry phenomena around areas of fibrosis is the most frequent mechanism of ventricular arrhythmia in CS. It is also possible that inflammation may play a role in initiating reentry with ventricular ectopy in CS patients, or by slowing conduction in diseased tissue. The best available data would suggest annual rates of VT of perhaps 1%-2% and 10%-15% in patients with initially clinically silent and clinically manifest disease, respectively. Current guidelines recommend a stepwise approach to VT management. The first suggested step is treatment with immunosuppression if there is evidence of active inflammation. Antiarrhythmic medications are often started at the same time, with catheter ablation considered if VT cannot be controlled. Activation and entrainment mapping and ablation are favored in the setting of hemodynamically tolerated VT. Substrate ablation targets areas of abnormal electrogram and favorable pace mapping using linear and/or cluster lesion sets with the goal of abolishing critical isthmuses and/or blocking VT exit sites. Epicardial mapping ablation is required in 20%-35% of cases. In general, more morphologies of VT are induced (often 3-4) and subsequent outcomes (recurrence rates 40%-50%) are less favorable than in other forms of nonischemic cardiomyopathy. The prognosis of CS is much improved and, as a result, more patients are developing VT during follow-up. Likely principally related to the complex disease substrate, VT ablation is technically challenging, with moderate outcomes, and much remains to be learned.

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

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