1172The increased serum level of troponin T after immunosuppression therapy reflects sustained myocardial FDG accumulation in cardiac sarcoidosis
Abstract Background and purpose Fluorine-18-flurodeoxyglucose positron emission computed tomography (18FDG-PET CT) is the sole but time-consuming and expensive examination assessing active inflammatory myocardium noninvasively in patients with cardiac sarcoidosis (CS). Though immunosuppression is used to treat CS, little is known about the cardiac biomarkers for determining therapeutic effect to immunosuppression therapy other than 18FDG-PET. Methods From Aug 2016, we prospectively enrolled 50 sarcoidosis patients with positively accumulated of FDG in the heart. The initial dose of prednisolone was 30mg/day, wherefrom the dose was tapered down 5mg/month until 6 months. After 6 months, follow-up 18FDG-PET was performed. Using 18FDG-PET images, we calculated total lesion glycolysis (TLG; SUVmeam x metabolic volume) and compared it to various cardiac markers. Non-responder was defined as TLG reduction rate <70% after immunosuppression therapy. Results In 50 CS patients, 41 patients had serial 18FDG-PET before and 6 months after immunosuppression therapy. 18FDG-PET images were acquired following 7 day's carbohydrate limitation and after at least 18-h fasting (mean free fatty acid level right before 18FDG-PET acquisition was 1.03 mEq/L). The mean age and plasma brain natriuretic peptide (BNP) level were 61.9 years old, 184 pg/mL at baseline, respectively. Because of immunosuppression therapy, TLG was significantly reduced from 195.3 (38.6–339.6) to 1.1 (0.01–7.37), p<0.001). Six (14.6%) patients were classified as NR group and the level of TnT at post therapy was significantly higher in NR group than responder-group (R-group) (0.021 (0.012–0.027) ng/ml vs 0.0095 (0.006–0.013) ng/ml, p=0.039) (Figure), while there were no significant differences between NR-group and R-group in the levels of ACE, sIL-2R, BNP, Dd, EF. Figure 1 Conclusions 1) By immunosuppression therapy using prednisolone for CS, about 85% patients showed significant reduction of increased myocardial FDG accumulation. 2) The sustained high level of serum TnT at post 6 months therapy indicates persistent inflammation of sarcoidosis in the heart, which could be an expedient marker for determining therapeutic effect.