Cardiac Sarcoidosis—Diagnostic and Therapeutic Challenges

Abstract

Sarcoidosis is a multisystem disorder of unknown etiology. The leading hypothesis involves an antigen-triggered dysregulated T-cell-driven immunologic response leading to non-necrotic granulomas. In cardiac sarcoidosis (CS), the inflammatory response can lead to fibrosis, culminating in clinical manifestations such as atrioventricular block and ventricular arrhythmias. Cardiac manifestations frequently present as first and isolated signs or may appear in conjunction with extracardiac manifestations. The incidence of sudden cardiac death (SCD) is high. Diagnosis remains a challenge. For a definite diagnosis, endomyocardial biopsy (EMB) is suggested. In clinical practice, compatible findings in advanced imaging using cardiovascular magnetic resonance (CMR) and/or positron emission tomography (PET) in combination with extracardiac histological proof is considered sufficient. Management revolves around the control of myocardial inflammation by employing immunosuppression. However, data regarding efficacy are merely based on observational evidence. Prevention of SCD is of particular importance and several guidelines provide recommendations regarding device therapy. In patients with manifest CS, outcome data indicate a 5-year survival of around 90% and a 10-year survival in the range of 80%. Data for patients with silent CS are conflicting; some studies suggest an overall benign course of disease while others reported contrasting observations. Future research challenges involve better understanding of the immunologic pathogenesis of the disease for a targeted therapy, improving imaging to aid early diagnosis, assessing the need for screening of asymptomatic patients and randomized trials.

Exploring the Role of Genetics in Sarcoidosis and Its Impact on the Development of Cardiac Sarcoidosis

“…The initial treatment for active CS includes corticosteroids (e.g., prednisolone 1 mg/kg/day), which have been demonstrated to increase long-term survival and recovery of AV conduction [110]. There is no consensus on the dosage of corticosteroids, but these regimes are tailored toward treatment response, which is assessed through clinical events and imaging.…”

“…There is no consensus on the dosage of corticosteroids, but these regimes are tailored toward treatment response, which is assessed through clinical events and imaging. Typically, this is often tapered and may be maintained for 12-24 months [110]. However, no impact was noted in terms of recovery of LV function [111].…”

“…The level of evidence is dependent on whether the LV ejection fraction is reduced, with the four pillars of treatment being an angiotensin-converting enzyme (ACE) inhibitor, angiotensin receptor blocker (ARB), or an angiotensin receptor/neprilysin inhibitor (ARNI), in combination with a mineralocorticoid receptor antagonist (MRA), sodium-glucose cotransporter-2 (SGLT2) inhibitor and beta-blocker. Volume overload is managed by diuretics, with mechanical assist devices and heart transplantation being reserved for those with a fulminant course or terminal heart failure [110]. Electrophysiologic management of CS includes anti-arrhythmic therapy, catheter-directed ablation, or implantable cardiac devices.…”