PO90 - Predictive value of FDG uptake in thoracic lymph nodes on PET/CT during immunosuppressive therapy in cardiac sarcoidosis patients
Beverly I. de Leeuw (Netherlands)1 2; Harold Mathijssen (Netherlands)1; Azar Kianzad (Netherlands)3; Fatima Akdim (Netherlands)1; Karim Taha (Netherlands)2; Maarten Jan Cramer (Netherlands)2; Marcel Veltkamp (Netherlands)3 4; Marco C. Post (Netherlands)1 2;
1 - Department of Cardiology, St. Antonius Hospital, Nieuwegein, The Netherlands; 2 - Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands; 3 - ILD Center of Excellence, Department of Pulmonology, St. Antonius Hospital, Nieuwegein, The Netherlands; 4 - Division of Heart and Lungs, University Medical Center Utrecht, Utrecht, The Netherlands;
Keywords: Cardiac sarcoidosis; Reactivation; FDG-PET/CT;
Select the theme: Cardiac Sarcoidosis
Type: Original Papers
Presentation: Poster Presentation

Introduction: Immunosuppression is recommended for patients with clinically manifest cardiac sarcoidosis (CS) or sufficient evidence of active myocardial inflammation. Immunosuppression is typically tapered when resolution of cardiac inflammation is achieved, since long-term use can lead to invalidating side effects. However, tapering immunosuppression carries a risk of cardiac reactivation and clinical decision-making can be hampered by discrepancies between inflammatory activity in the myocardium and thoracic lymph nodes.

Objectives: This study aimed to examine whether 18F-fluorodeoxyglucose (FDG) uptake in thoracic lymph nodes on positron emission tomography/computed tomography (PET/CT) during immunosuppression predicts cardiac reactivation in CS patients.

Materials and Methods: We retrospectively studied a consecutive cohort of CS patients diagnosed between January 2010 and December 2022. Eligible patients received immunosuppression, achieved complete resolution of cardiac FDG uptake, and underwent PET/CT during follow-up. The potential to predict CS reactivation based on both persistent or new FDG uptake in thoracic lymph nodes during immunosuppression was quantified by sensitivity, specificity, predictive values and area under the ROC curve (AUC).

Results: The study population comprised 156 CS patients with mean age 52.5 ± 9.3 years and included 105 (67.3%) males. The mean time interval between resolution of cardiac FDG uptake and the first follow-up PET/CT was 12.1 ± 7.3 months. This scan demonstrated myocardial reactivation in 45 patients (28.8%). FDG uptake in thoracic lymph nodes during immunosuppression was observed in 21/45 (46.7%) patients with CS reactivation and 40/111 (36.0%) patients without CS reactivation. Sensitivity, specificity, positive and negative predictive values for predicting cardiac reactivation were 46.7%, 64.0%, 34.4% and 74.7%, respectively. The AUC was 0.553.

Conclusions: FDG uptake in thoracic lymph nodes on PET/CT during immunosuppression in CS patients did not predict cardiac reactivation in our study. These findings suggest that FDG uptake in thoracic lymph nodes alone should not refrain physicians from tapering immunosuppression after resolution of myocardial inflammation has been achieved.