%0 Journal Article %A Shana Elman %A Michael Bindschadler %A Bradley Petek %A Richard Cheng %A Kris Patton %A Laurie Soine %A Adam Alessio %T Cardiac PET/CT in the Management of Cardiac Sarcoidosis: Association of FDG Uptake with Changes in Symptoms and Medications %D 2017 %J Journal of Nuclear Medicine %P 515-515 %V 58 %N supplement 1 %X 515Objectives: FDG PET/CT is increasingly used to diagnose cardiac sarcoidosis (CS), and also shows promise in guiding clinical management of CS. However, few data exist evaluating the association between clinical course and changes in FDG uptake. Given the pathologic linkage between inflammation and clinical course, this study tests the hypothesis that decreased inflammation on FDG evaluation predicts improvement in clinical symptoms.Methods: This retrospective study evaluated FDG uptake on serial Resting Rb82+Fasting FDG PET/CT scans in patients with CS (N=79 unique exams from 20 patients representing 57 intervals for change analysis). At each exam date, NYHA functional class, as well as corticosteroid and immunomodulator use was recorded. For each exam interval, symptoms were determined to be worse, stable, or improved based on clinical notes within a month of the PET exams. We developed software and extracted 10 quantitative measures of FDG uptake, including previously proposed cardiac metabolic volume (CMV), activity (CMA), and maximum SUV. Change analysis was performed by calculating absolute and percent changes for each interval. FDG measures were compared with NYHA class, medications at the time of PET, and stability/change in clinical status.Results: In our cohort, patients had worsening symptoms in 15, stable symptoms in 22, and improvement in 20 intervals. For these intervals, the FDG uptake tended to increase for worsening symptoms patients although no metric was statistically significant. For example, the percent change in SUVmax between initial and followup exam for worsening, stable, and improved patients was 13+/69, -9+/-46, -29+/127 % revealing substantial noise in these studies. Of all metrics tested, change in SUVmax provided the highest accuracy in identifying patients with worsening symptoms (area under ROC curve 0.60) with 74% accuracy using a threshold of >1.1 g/ml increase in SUVmax. Prednisone at the time of FDG exam was associated with lower FDG uptake even within matched functional classifications. For example, for moderately symptomatic patients (NYHA class 2 or 3; N=54 exams), SUVmax for prednisone present versus absent was 4.2+/2.5 vs 7.1+/-3.5 g/ml (p=0.001) and the CMA was 172 +/-199 vs 361+/-374 g (p=0.02).Conclusion: While there is an association between worsening symptoms and increased FDG uptake in the myocardium, FDG uptake alone is not a strong predictor of symptom changes (AUC only 0.6). These results may be confounded by numerous factors including many known limitations of myocardial FDG inflammation imaging (e.g., incomplete FDG suppression, spatial resolution, motion) and the unknown impact of the effect of ongoing steroid therapy on baseline FDG trapping. These initial results suggest that patients with similar functional class had reduced FDG uptake if they were on steroids. Further work is needed to assess if steroids reduce FDG uptake independent of their therapeutic value. Research Support: None %U