Cardiac sarcoidosis: the cardiomyopathy of a thousand faces-a narrative review

Abstract

Introduction: Cardiac sarcoidosis (CS) is a complex inflammatory cardiomyopathy resulting from myocardial granulomatous inflammation. Its variable clinical presentation and lack of a single definitive test make diagnosis challenging. CS causes significant morbidity and mortality through conduction abnormalities, ventricular arrhythmias, heart failure (HF), and sudden cardiac death (SCD). This review synthesizes current knowledge on CS epidemiology, pathophysiology, diagnosis, and management.

Materials and methods: A comprehensive, non-systematic literature search was performed using PubMed/MEDLINE, Embase, and Google Scholar for English-language articles focusing on publications from January 2010 to May 2025. Original research, systematic reviews, meta-analyses, consensus statements, and guidelines were included.

Results: Recent evidence indicates a paradigm shift in CS diagnosis, with advanced cardiac imaging gaining central place in international algorithms. Cardiac magnetic resonance (CMR), 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), and hybrid CMR/FDG-PET have revolutionized CS diagnosis and management. Histological confirmation of sarcoidosis, when pursued, is obtained via extracardiac biopsy; cardiac involvement is then established using clinical and imaging criteria. Endomyocardial biopsy is reserved for select cases. Immunomodulation, primarily corticosteroids, remains the therapeutic cornerstone, with adjunctive steroid-sparing agents and biologics. Implantable cardioverter-defibrillators are indicated in high-risk patients to prevent ventricular arrhythmias and SCD. HF management follows guideline-directed therapy, reserving advanced therapies for CS-related advanced HF.

Conclusion: CS is "the cardiomyopathy of a thousand faces". International consensus emphasizes advanced imaging and multidisciplinary approaches for timely diagnosis and management. While immunomodulation and device therapy have improved outcomes, knowledge gaps persist regarding optimal treatment strategies. Future research should refine diagnostic algorithms, identify CS-specific biomarkers, and develop optimal and novel therapeutics to improve CS management.