Sarcoidosis and atrial fibrillation: a rare association and interlink with inflammation

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.

A systematic review and meta-analysis of the prevalence, incidence, and predictors of atrial fibrillation in cardiac sarcoidosis

BACKGROUND

The occurrence of atrial arrhythmias, in particular, atrial fibrillation (AF) in patients with cardiac sarcoidosis (CS) are of growing interest in the field of infiltrative cardiomyopathies. Via a systematic review with meta-analysis, we sought to synthesize data on the prevalence, incidence, and predictors of atrial arrhythmias as well as outcomes in patients with CS.

METHODS

PubMed/Medline, Web of Science, and Scopus were systematically queried from inception until April 26th, 2023. Using the random-effects model, separate plots were generated for each effect size assessed.

RESULTS

From a total of 8 studies comprising 978 patients with CS, the pooled summary estimates for the prevalence of AF was 23% (95% CI: 13%-34%). Paroxysmal AF was the most common subtype of AF (83%; 95% CI: 77%-90%), followed by persistent AF (17%; 95% CI: 10%-23%). In 9 studies involving 545 patients with CS, the pooled incidence of AF was estimated at 5%, 13.1%, and 8.9% at <2 years, 2-4 years, and > 4 years of follow-up respectively, with an overall cumulative incidence of 10.6% (95% CI: 4.9%-17.8%) over a 6-year follow-up period. Increased left atrial size and atrial 18F-fluorodeoxyglucose uptake were identified as strong independent predictors for the development of atrial arrhythmias on qualitative synthesis.

CONCLUSION

The burden of AF and related arrhythmias in CS patients is considerable. This necessitates close follow-up and predictive risk-stratification tools to guide the initiation of appropriate strategies, including therapeutic interventions for prevention of AF-related embolic phenomenon, especially in those with known clinical predictors.

Atrial tachyarrhythmia as a presenting symptom leading to the diagnosis of pulmonary sarcoidosis treated with catheter-based ablation

A 55-year-old woman was referred for recurrent palpitations. A 48-hour ambulatory cardiac monitor revealed an atrial tachycardia rate up to 170 beats per minute. A subsequent electrophysiology study revealed atrial fibrillation and both typical and atypical atrial flutter. Computed tomography revealed multiple pulmonary nodules, and an endobronchial ultrasound-guided fine-needle aspiration confirmed the diagnosis of pulmonary sarcoidosis. The patient underwent radiofrequency ablation of the cavotricuspid isthmus and left common, right superior, and right inferior pulmonary vein isolation via cryoablation, without recurrent symptoms.

Comparing and Contrasting Guidelines for the Management of Cardiac Sarcoidosis

Introduction: The Japanese Circulation Society (JCS) recently published new guidelines for the diagnosis and treatment of Cardiac Sarcoidosis (CS). There are two other guideline documents, the World Association of Sarcoidosis and Other Granulomatous Disorders Sarcoidosis Organ (WASOG) Assessment Instrument created in 1999 and updated in 2014. Also, in 2014, the Heart Rhythm Society (HRS) published their international guideline document. As co-chair of the HRS document I have been invited to compare and contrast the management aspects of the HRS guidelines with the new JCS document. Comments: (i) The HRS document recommended a stepwise approach to VT management and the JCS document is somewhat similar; but with some key differences. (ii) The HRS statement suggested that an ICD for CS patients with an indication for a pacemaker "can be useful". The JCS document take a similar position although with some additional criteria related to National Health Institute Coverage guidelines. (iii) Both HRS and the JCS documents agree that ICDs are recommended in patients with general guideline indications for primary prevention (i.e. LVEF less than 35%). However which additional patients should be considered for ICDs is controversial. The 2016 JCS document is broadly similar, with the major exception that it is recommended that all patients with LVEF 35-50% should have an EP study. Conclusion: The Japanese have been leaders in many aspects of CS including in guideline development. It is clear that the future of CS management is bright, with increasing international collaborations and also multiple efforts underway to obtain higher quality data to inform future guidelines.

Atrial Arrhythmias in Clinically Manifest Cardiac Sarcoidosis: Incidence, Burden, Predictors, and Outcomes

Background

Recent data have suggested a substantial incidence of atrial arrhythmias (AAs) in cardiac sarcoidosis (CS). Our study aims were to first assess how often AAs are the presenting feature of previously undiagnosed CS. Second, we used prospective follow‐up data from implanted devices to investigate AA incidence, burden, predictors, and response to immunosuppression.

Methods and Results

This project is a substudy of the CHASM‐CS (Cardiac Sarcoidosis Multicenter Prospective Cohort Study; NCT01477359). Inclusion criteria were presentation with clinically manifest cardiac sarcoidosis, treatment‐naive status, and implanted with a device that reported accurate AA burden. Data were collected at each device interrogation visit for all patients and all potential episodes of AA were adjudicated. For each intervisit period, the total AA burden was obtained. A total of 33 patients met the inclusion criteria (aged 56.1±7.7 years, 45.5% women). Only 1 patient had important AAs as a part of the initial CS presentation. During a median follow‐up of 49.1 months, 11 of 33 patients (33.3%) had device‐detected AAs, and only 2 (6.1%) had a clinically significant AA burden. Both patients had reduced burden after CS was successfully treated and there was no residual fluorodeoxyglucose uptake on positron emission tomography scan.

Conclusions

First, we found that AAs are a rare presenting feature of clinically manifest cardiac sarcoidosis. Second, AAs occurred in a minority of patients at follow‐up; the burden was very low in most patients. Only 2 patients had clinically significant AA burden, and both had a reduction after CS was treated.

Registration

URL: https://www.clini​caltr​ials.gov; unique identifier NCT01477359.

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.

Atrial Arrhythmias and Atrial Involvement in Cardiac Sarcoidosis

Severe ventricular arrhythmias such as high-grade atrioventricular block and ventricular tachycardia may cause lethal conditions or sudden death in patients with cardiac sarcoidosis (CS). Physicians should examine patients carefully for these conditions and treat them appropriately. As arrhythmias are being better diagnosed and treated, physicians are increasingly aware of atrial arrhythmias, which have not been focused upon as CS-related conditions, in patients with CS. This article reports a case of atrial flutter in sarcoidosis, and discusses literature findings on atrial arrhythmias and atrial involvement of CS. It is highly likely that atrial arrhythmia and supraventricular conduction disorder associated with or caused by CS are more common than previously thought. Physicians should pay careful attention for these conditions in the diagnosis and treatment of CS.

Management of Arrhythmias Associated with Cardiac Sarcoidosis

Sarcoidosis is a multisystem granulomatous disorder of unknown etiology. The annual incidence of systemic sarcoidosis is estimated at 10-20 per 100,000 individuals. Owing to the recent advances in imaging modalities, cardiac sarcoidosis (CS) is diagnosed more frequently. The triad of CS includes conduction abnormality, ventricular tachycardia, and heart failure. Atrial and ventricular arrhythmias are caused by either inflammation or scar formation. Inflammation should be treated with immunosuppression and antiarrhythmic agents and scar formation should be treated with antiarrhythmics and/or ablation, in addition to implantable cardioverter defibrillator (ICD) implantation, if necessary. Ablation can provide a good outcome, but it might require bipolar ablation if the critical portion is located mid-myocardium. Late recurrence might be caused by reactivation of sarcoidosis, which would need to be evaluated by positron emission tomography-computed tomography imaging. Risk of sudden cardiac death (SCD) in patients with advanced atrioventricular block is not low, and ICD implantation could be considered instead of a pacemaker. For risk stratification for SCD, late gadolinium enhancement by cardiac magnetic resonance imaging or program stimulation is often used.

Atrial Fibrillation and Ventricular Tachycardia in a Patient with Cardiac Sarcoidosis

Cardiac sarcoidosis (CS) can cause atrial and ventricular arrhythmias, conduction system disease, and congestive heart failure. The use of advanced imaging modalities including cardiac magnetic resonance and positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro-D-glucose can be helpful in evaluating the extent of disease and response to treatment. The management of CS patients can be challenging, requiring immunosuppression medications, antiarrhythmic drugs, implantable cardiac devices, and cardiac ablation procedures. We report a patient with CS initially presenting with paroxysmal atrial fibrillation who later developed polymorphic ventricular tachycardia, highlighting the complexity of diagnosis and management in patients with multisystem sarcoidosis.

Cardiac Sarcoidosis: A Review of Contemporary Challenges in Diagnosis and Treatment

Sarcoidosis is a systemic disease characterized by noncaseating granulomas and is often a diagnosis of exclusion. The actual prevalence of cardiac sarcoidosis (CS) is unknown, as studies have demonstrated mixed data. CS may be asymptomatic and is likely more frequently encountered than previously thought. Sudden death may often be the presenting feature of CS. Most deaths attributed to CS are caused by arrhythmias or conduction system disease, and congestive heart failure may occur. Current expert consensus on diagnosis of CS continues to rely on endomyocardial biopsy, in the absence of which, histologic proof of extracardiac sarcoid involvement is necessitated. Emergence of newer noninvasive imaging modalities such as cardiac magnetic resonance imaging and positron emission tomography, have become increasingly popular tools utilized in patients with both clinical and asymptomatic CS, and have demonstrated good diagnostic capability. The main therapeutic approaches in patients with CS can be broadly divided into the following 2 categories: pharmacological management and invasive or device oriented. However, much remains unknown about the optimal screening protocols of asymptomatic patients with extracardiac sarcoidosis and treatment of biopsy-proven CS. Our knowledge about CS has amplified significantly over the last 30 years and the growing realization that this process is often asymptomatic is paving the way for better screening protocols and earlier detection of this serious condition.

Atrial Fibrillation in Cardiac Sarcoidosis

Sarcoidosis is a systemic granulomatous disease that affects the myocardium. Although ventricular arrhythmias are well known manifestations of cardiac involvement, there is increasing evidence that a significant proportion of patients with cardiac sarcoidosis (CS) also have atrial arrhythmias, atrial fibrillation being the most frequent. The incidence and mechanism of atrial fibrillation in CS is not precisely known. The management of atrial fibrillation in patients with CS is currently done according to the general guidelines for management of atrial fibrillation. Evidence is emerging regarding the additional role of immunosuppression for the treatment of atrial arrhythmias in CS. This paper reviews the incidence, possible mechanisms and treatment strategies of atrial fibrillation in patients with CS.

Cardiac Sarcoidosis

Studies suggest clinically manifest cardiac involvement occurs in 5% of patients with pulmonary/systemic sarcoidosis. The principal manifestations of cardiac sarcoidosis (CS) are conduction abnormalities, ventricular arrhythmias, and heart failure. Data indicate that an 20% to 25% of patients with pulmonary/systemic sarcoidosis have asymptomatic (clinically silent) cardiac involvement. An international guideline for the diagnosis and management of CS recommends that patients be screened for cardiac involvement. Most studies suggest a benign prognosis for patients with clinically silent CS. Immunosuppression therapy is advocated for clinically manifest CS. Device therapy, with implantable cardioverter defibrillators, is recommended for some patients.