Cardiac Sarcoidosis: A Practical Guide for Cardiologists

Cardiac sarcoidosis (CS) is an inflammatory granulomatous cardiomyopathy associated with atrioventricular block, ventricular arrhythmias, heart failure (HF), and sudden cardiac death (SCD). Diagnosis and management remain challenging because myocardial involvement is patchy and evidence from randomized trials is limited. This review summarizes current knowledge on CS, focusing on advances in diagnosis, immunosuppression, and prevention of arrhythmic events.

Cardiac involvement is clinically recognized in 5-10% of patients with sarcoidosis but is more frequent in imaging and autopsy studies. Cardiac magnetic resonance (CMR) and ^18F-fluorodeoxyglucose positron emission tomography (FDG-PET) provide complementary information on myocardial scar and active inflammation. Multimodality imaging, extracardiac tissue diagnosis, guided endomyocardial biopsy, and consensus criteria improve diagnostic confidence. Corticosteroids remain first-line therapy for active inflammation, while steroid-sparing agents are increasingly used to reduce corticosteroid exposure or treat persistent disease. Inflammasome/interleukin-1 inhibition is an emerging targeted strategy, but its clinical efficacy remains unproven. SCD risk stratification now extends beyond left ventricular ejection fraction to include ventricular arrhythmias, conduction disease, ventricular dysfunction, and myocardial scar burden. Implantable cardioverter-defibrillator therapy remains central in selected high-risk patients. CS requires early recognition of both inflammation and myocardial scar. CMR and FDG-PET are central to diagnosis, prognosis, and therapeutic decisions, while management combines immunosuppression, HF therapy, and arrhythmia prevention. Major uncertainties remain regarding optimal diagnostic criteria, immunosuppression strategies, serial imaging, and primary-prevention ICD selection. Prospective studies and randomized trials are needed to refine treatment and risk stratification.