A case series on inflammatory cardiomyopathy and suspected cardiac sarcoidosis: role of cardiac PET in management

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.

Extrapulmonary sarcoidosis with a focus on cardiac, nervous system, and ocular involvement

Sarcoidosis is a poorly understood granulomatous disease that involves the lungs and/or intrathoracic lymph nodes in more than 90% of cases. Although pulmonary sarcoidosis is the leading cause of mortality in this disease, this review focuses on three sites of extrapulmonary involvement (heart, nervous system, and eyes), since involvement of any of these sites can be catastrophic, leading to death, debilitation, or blindness. Patients with cardiac, ocular and neurosarcoidosis necessitate a multidisciplinary approach with careful and long-term follow-up. Prompt diagnosis with imaging and/or biopsy and treatment is required to avoid irreversible damage. Corticosteroids are the mainstay of therapy and are often associated with rapid and durable remissions. Immunosuppressive or biologic agents are reserved for patients failing or experiencing side effects from steroids. Managing sarcoidosis requires vigilance, judgement, and awareness of the vagaries of this fascinating disease.