Diagnoses, management patterns, and outcomes of cardiac sarcoidosis in South Africa.

Background: Sarcoidosis is an idiopathic multiorgan disease characterized by tissue infiltration by noncaseating granulomas. Clinical cardiac involvement is reported in approximately 5% of patients. However, the frequency of cardiac involvement is found to be higher on autopsy and in advanced imaging studies such as cardiac magnetic resonance imaging. Objective: The purpose of this study was to determine contemporary diagnoses, management, and outcomes of cardiac sarcoidosis (CS) in South Africa. Methods: Clinical records of patients diagnosed with CS between January 2000 and December 2021 were reviewed. Results: Twenty-two patients were diagnosed with CS during the study period. The patients had a mean (± SD) age of 45.2 ± 12.3 years at the time of presentation. CS diagnostic rates increased from 4.5% in 2000-2005 to 45.5% in 2016-2021. Fifteen of the 22 patients (68.2%) were newly diagnosed with sarcoidosis at the time of CS diagnosis, and 9 of the 15 (60%) had pulmonary involvement. Of the 22 patients diagnosed with CS, 13 (59.1%) presented in combination with heart block, 10 (45.5%) with ventricular arrhythmias, and 4 (18.2%) with heart failure. Five endomyocardial biopsies were performed, and all were nondiagnostic. However, 8 of 8 endobronchial ultrasound (EBUS)-guided biopsies of thoracic lymph nodes were diagnostic of sarcoidosis and, notably, excluded tuberculosis. Fourteen patients (63.6%) were treated with corticosteroids, 7 (31.8%) with azathioprine, 9 (40.9%) with amiodarone, and 16 (72.7%) with a cardiac implantable electronic device. After a mean follow-up period of 64.5 ± 50.5 months, no deaths had occurred. Conclusion: CS diagnostic rates have increased over time. Diagnostic endomyocardial biopsies have a low diagnostic yield, whereas EBUS-guided biopsy of thoracic lymph nodes is of crucial diagnostic utility.