Prognostic value of 18F-fluorodeoxyglucose positron emission tomography one month after initiation of prednisolone therapy in patients with cardiac sarcoidosis

Abstract

Background

Current guidelines for cardiac sarcoidosis (CS) recommend maintaining the initial maximal dose of prednisolone (PSL) for one month after initiation; however, the prognostic significance of ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) performed at this time point remains unclear. We sought to investigate whether FDG-PET performed at one month after the initiation of PSL is associated with adverse events in patients with CS.

Methods

We examined 109 consecutive CS patients who underwent FDG-PET at diagnosis and one month after initiating PSL between January 2010 and January 2025 in a university hospital. The change in maximum standardized uptake value (SUV_max) from baseline to one month was calculated. Responder was defined as those with an SUV_max reduction ≥25%, while non-responder had a reduction <25% or any increase. The primary outcome was a composite of aborted sudden cardiac death, sustained ventricular tachycardia, hospitalization of worsening heart failure, and all-cause death.

Results

Of the 109 patients, 83 were classified as responder and 26 as non-responder. Over a median follow-up of 4.9 years (interquartile range, 2.3–8.2), the primary outcome occurred in 37 patients. Non-responder had a significantly higher risk of the primary outcome, and this association persisted after sequential adjustment for established prognostic covariates.

Conclusions

An inadequate reduction in SUV_max on FDG-PET performed one month after PSL initiation was independently associated with adverse clinical events in patients with CS. These findings suggest that non-responder represents a clinical challenge and even very early follow-up FDG-PET may provide prognostic insights.