Investigating the treatment phenotypes of cardiac sarcoidosis: A prospective cohort study.

Introduction: Data indicates there are 4 main pulmonary sarcoidosis duration/treatment phenotypes: asymptomatic, acute (disease duration <1-2 years), chronic and advanced. There are no data about disease duration/treatment phenotypes of cardiac sarcoidosis patients. Our study had 2 main aims (i) to assess the response to corticosteroids and (ii) to assess the incidence of relapse after a one-year course of corticosteroids (thereby classifying patients as acute or chronic treatment phenotype). Methods: Consecutive, treatment naive patients with CS were prospectively recruited and treated with 0.5 mg/kg prednisone, to a maximum dose of 40 mg/day. Patients had a follow-up PET after 3-6 months of therapy (PET 2). In the responders (PET definition of response) the prednisone was then weaned and stopped after 12 months. Three months after stopping, the PET was repeated to look for disease relapse (PET 3). Results: Twenty-one consecutive patients were included, and all patients showed a reduction in cardiac FDG uptake after 3-6 months and 19/21 (90.5 %) met the PET definition of response. Of these, 12/19 (63.1 %) relapsed after prednisone was stopped. There were no serious adverse effects during the trial of therapy cessation and there were no later relapses in the 7 non-relapsers during over 4 years of subsequent follow-up. Conclusion: The initial response rate to prednisone was high with all patients showing a reduction in FDG uptake and 19/21 meeting a PET definition of >25 % response. Secondly, a trial of therapy discontinuation was able to classify 7/19 patients as acute treatment phenotype and 12/19 as chronic.