Natural evolution of cardiac sarcoidosis in an asymptomatic patient: a case report

BACKGROUND: Sarcoidosis is a multi-organ granulomatous disease of unknown aetiology. Adverse outcome related with cardiac involvement, makes early diagnosis of cardiac sarcoidosis crucial. CASE SUMMARY: In a 55-year-old man presenting with recurrent pulmonary infections, computed tomography (CT) showed several enlarged mediastinal lymph nodes and no lung pathology. Subsequent mediastinoscopy revealed the diagnosis of sarcoidosis. Further screening for organ involvement showed multifocal cardiac involvement both on cardiac magnetic resonance (CMR) and 18-F-fluorodeoxyglucose-positron emission tomography-computed tomography ((18)F-FDG PET-CT). Because of the lack of functional deterioration and clinical symptoms, no steroid treatment was initiated and regular follow-up of cardiac abnormalities was performed by CMR. Unremarkable progression of cardiac involvement during the first 2 years of follow-up turned into a dramatic involvement after 4 years, with the increase in the number and size of lesions at late gadolinium enhancement (LGE) CMR. Late gadolinium enhancement areas matched the regions of strongly increased (18)F-FDG uptake. For the first time, the patient started complaining on shortness of breath, electrocardiography showed an atrioventricular block Grade 1. Cardiac biomarkers and cardiac function were still preserved. Steroid treatment was started. Although an electrophysiology study was negative, Holter monitoring showed ventricular arrhythmia. Cardioverter-defibrillator was implanted. DISCUSSION: This case shows the progression of cardiac sarcoidosis on CMR in an asymptomatic untreated patient over a 4-year period, and rises the awareness of possible severe cardiac damage even in the absence of clinical signs of cardiac involvement. Combination of PET and CMR is appealing to better understand the evolution of cardiac sarcoidosis and may help in the management of such patients.