The chameleon of cardiology: cardiac sarcoidosis before and after heart transplantation

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.

Recurrent Cardiac Sarcoidosis and Giant Cell Myocarditis After Heart Transplant: A Case Report and Systematic Literature Review

Recurrence of cardiac sarcoidosis (CS) and giant cell myocarditis (GCM) after heart transplant is rare, with rates of 5% in CS and 8% in GCM. We aim to identify all reported cases of recurrence in the literature and to assess clinical course, treatments, and outcomes to improve understanding of the conditions. A systematic review, utilizing Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines, was conducted by searching MEDLINE/PubMed and Embase of all available literature describing post-transplant recurrent granulomatous myocarditis, CS, or GCM. Data on demographics, transplant, recurrence, management, and outcomes data were collected from each publication. Comparison between the 2 groups were made using standard statistical approaches. Post-transplant GM recurrence was identified in 39 patients in 33 total publications. Reported cases included 24 GCM, 12 CS, and 3 suspected cases. Case reports were the most frequent form of publication. Mean age of patients experiencing recurrence was 42 years for GCM and 48 years for CS and favored males (62%). Time to recurrence ranged from 2 weeks to 9 years post-transplant, occurring earlier in GCM (mean 1.8 vs 3.0 years). Endomyocardial biopsies (89%) were the most utilized diagnostic method over cardiac magnetic resonance and positron emission tomography. Recurrence treatment regimens involved only steroids in 40% of CS, whereas other immunomodulatory regimens were utilized in 70% of GCM. In conclusion, GCM and CS recurrence after cardiac transplantation holds associated risks including concurrent acute cellular rejection, a higher therapeutic demand for GCM recurrence compared with CS, and mortality. New noninvasive screening techniques may help modify post-transplant monitoring regimens to increase both early detection and treatment of recurrence.

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.

Cardiac sarcoidosis completely mimicking biventricular arrhythmogenic cardiomyopathy

Cardiac sarcoidosis (CS) is a chameleon of cardiology, and it can mimic different cardiac diseases; among them is arrhythmogenic cardiomyopathy (ACM). We admitted a 70-year-old female patient with heart failure symptoms in 2015, who fulfilled all major ECG and non-invasive imaging criteria of biventricular ACM. She was well with the recommended medications for 3 years, showing only isolated cardiac involvement, but in 2018, cervical and mediastinal lymphadenopathy appeared and cervical lymph node core biopsy histology, bronchoalveolar lavage flow cytometry strongly suggested extracardiac sarcoidosis. Therefore, our suspicion was that sarcoidosis is responsible for the cardiac involvement, which was not confirmed by PET-CT and gallium scintigraphy examinations. At the end of 2018, she died in septicaemia with multiorgan failure, and only autopsy verified her CS. A new ECG algorithm published in 2021 for the differential diagnosis of CS and biventricular ACM, when applied on her ECGs recorded in 2015, suggested the diagnosis of CS.

Non-18F-FDG/18F-NaF Radiotracers Proposed for the Diagnosis and Management of Diseases of the Heart and Vasculature

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) and ¹⁸F-sodium fluoride (¹⁸F-NaF) are front-runners in PET. However, these tracers have limitations in the imaging of diseases in the heart. A multitude of other radiotracers have been identified as potentially useful PET agents in the identification of cardiovascular disease. This critical review examines recent studies with the use of non-¹⁸F-FDG/¹⁸F-NaF radiotracers in the identification and surveillance of cardiovascular diseases. We highlight the need for further investigation into alternative PET radiotracers to demonstrate their clinical value in the management of these pathologies.

Heart failure in the last year: progress and perspective

Research about heart failure (HF) has made major progress in the last years. We give here an update on the most recent findings. Landmark trials have established new treatments for HF with reduced ejection fraction. Sacubitril/valsartan was superior to enalapril in PARADIGM-HF trial, and its initiation during hospitalization for acute HF or early after discharge can now be considered. More recently, new therapeutic pathways have been developed. In the DAPA-HF and EMPEROR-Reduced trials, dapagliflozin and empagliflozin reduced the risk of the primary composite endpoint, compared with placebo [hazard ratio (HR) 0.74; 95% confidence interval (CI) 0.65-0.85; P < 0.001 and HR 0.75; 95% CI 0.65-0.86; P < 0.001, respectively]. Second, vericiguat, an oral soluble guanylate cyclase stimulator, reduced the composite endpoint of cardiovascular death or HF hospitalization vs. placebo (HR 0.90; 95% CI 0.82-0.98; P = 0.02). On the other hand, both the diagnosis and treatment of HF with preserved ejection fraction, as well as management of advanced HF and acute HF, remain challenging. A better phenotyping of patients with HF would be helpful for prognostic stratification and treatment selection. Further aspects, such as the use of devices, treatment of arrhythmias, and percutaneous treatment of valvular heart disease in patients with HF, are also discussed and reviewed in this article.

Differentiating hereditary arrhythmogenic right ventricular cardiomyopathy from cardiac sarcoidosis fulfilling 2010 ARVC Task Force Criteria

BACKGROUND

The clinical presentation of cardiac sarcoidosis (CS) may resemble that of arrhythmogenic right ventricular cardiomyopathy (ARVC).

OBJECTIVE

The purpose of this study was to identify clinical variables to better discriminate between patients with genetically determined ARVC and those with CS fulfilling definite 2010 ARVC Task Force Criteria (TFC).

METHODS

In this multicenter study, 10 patients with CS fulfilling definite 2010 ARVC TFC were age and gender matched with 10 genetically proven ARVC patients. A cardiac ¹⁸F-fluorodeoxyglucose positron emission tomographic (¹⁸F-FDG PET) scan was required for patients to be included in the study.

RESULTS

The 2010 ARVC TFC did not reliably differentiate between the 2 diseases. CS patients presented with longer PR intervals, advanced atrioventricular block (AVB), and longer QRS duration (P <.001 and P = .009, respectively), whereas T-wave inversions (TWIs) in the peripheral leads were more common in ARVC patients (P = .009). CS patients presented with more extensive left ventricular involvement and lower left ventricular ejection fraction (LVEF), whereas ARVC patients had a larger right ventricular outflow tract (RVOT) (P = .044). PET scan positivity was only present in CS patients (90% vs 0%).

CONCLUSION

The 2010 ARVC TFC do not reliably differentiate between CS patients fulfilling 2010 ARVC TFC and those with hereditary ARVC. Prolonged PR interval, advanced AVB, longer QRS duration, right ventricular apical involvement, reduced LVEF, and positive ¹⁸F-FDG PET scan should raise the suspicion of CS, whereas larger RVOT dimensions, subtricuspid involvement and peripheral TWI favor a diagnosis of hereditary ARVC.

The chameleon of cardiology: cardiac sarcoidosis before and after heart transplantation

Cardiac sarcoidosis is a chronic inflammatory disease with a large spectrum of symptoms that can mimic diseases such as dilated, hypertrophic, or arrhythmogenic cardiomyopathies. It can be asymptomatic but can also present with ventricular arrhythmias, conduction disease, and heart failure (HF) or even sudden cardiac death (SCD). We present here the case of a patient transplanted due to end‐stage arrhythmogenic right ventricular cardiomyopathy (ARVC), fulfilling the task force criteria. A few years after successful heart transplantation (HTX), the patient developed similar symptoms and morphofunctional changes of the heart, which led to critical re‐evaluation of his primary diagnosis.