Screening for cardiac sarcoidosis: diagnostic approach and long-term follow-up in a tertiary centre

Background Cardiac sarcoidosis (CS) is associated with poor prognosis, making early diagnosis and treatment important. This study evaluated the results of a diagnostic approach in patients with known sarcoidosis and suspected cardiac involvement in a tertiary centre and their long-term outcomes. Methods We included 180 patients with sarcoidosis and a clinical suspicion of CS. In addition to an electrocardiogram (ECG)/transthoracic echocardiogram (TTE), cardiovascular magnetic resonance imaging (CMR) and positron emission tomography (PET) were performed in 66% and 37% of the patients, respectively. The diagnosis of CS was based on the Heart Rhythm Society criteria. Follow-up was performed, and a composite endpoint of sustained ventricular tachycardia, ventricular fibrillation, aborted sudden cardiac death, heart failure hospitalisation, heart transplantation or cardiac death was used for the survival analysis. Results Symptoms were present in 87% of the patients, and ECG/TTE abnormalities were found in 92/180 patients (51%). Using CMR and/or PET, 31/92 patients (34%) were diagnosed with CS. In 15 patients, an alternative diagnosis was found. CS was diagnosed in 11/88 patients (13%) without ECG/TTE abnormalities. During a median follow-up time of 4.4 years (interquartile range: 2.3-6.8), 11 composite endpoints occurred, more frequently in CS patients than in sarcoidosis patients without cardiac involvement (p < 0.001). Patients with ECG/TTE abnormalities at baseline had worse outcomes than those without abnormalities (p = 0.019). Conclusion CS was diagnosed in 23% of the referred sarcoidosis patients. ECG/TTE were of limited diagnostic value for screening for CS but seemed to have important prognostic value as patients with normal ECG/TTE results who did meet the diagnostic CS criteria had a very good prognosis. CMR/PET provided a good diagnostic yield and identified other cardiac diseases.