FDG-PET in possible cardiac sarcoidosis: Right ventricular uptake and high total cardiac metabolic activity predict cardiovascular events

Abstract

Background. Cardiac involvement accounts for the majority of morbidity and mortality in sarcoidosis. Pathological myocardial fluorodeoxyglucose (FDG)-uptake in positron emission tomography (PET) has been associated with cardiovascular events and quantitative metabolic parameters have been shown to add prognostic value. Our aim was to study whether the pattern of pathological cardiac FDG-uptake and quantitative parameters are able to predict cardiovascular events in patients with suspected cardiac sarcoidosis (CS). Methods. 137 FDG-PET examinations performed in Tampere University Hospital were retrospectively analyzed visually and quantitatively. Location of pathological uptake was noted and pathological metabolic volume, average standardized uptake value (SUV), and total cardiac metabolic activity (tCMA) were calculated. Patients were followed for ventricular tachycardia, decrease in left ventricular ejection fraction, and death. Results. Eleven patients had one or more cardiovascular events during the follow-up. Five patients out of 12 with uptake in both ventricles had an event during follow-up. Eight patients had high tCMA (> 900 MBq) and three of them had a cardiovascular event. Right ventricular uptake and tCMA were significantly associated with cardiovascular events during follow-up (Pvalue .001 and .018, respectively). Conclusions. High tCMA and right ventricular uptake were significant risk markers for cardiac events among patient with suspected CS. (J Nucl Cardiol 2019) Key Words: Sarcoid heart dusease inflammation AE PET AE metabolism imaging agents Abbreviations PET Positron emission tomography FDG Fluorodeoxyglucose CS Cardiac sarcoidosis LV Left ventricle RV Right ventricle CV Cardiovascular LVEF Left ventricular ejection fraction tCMA Total cardiac metabolic activity SUV Standardized uptake value AV Atrio-ventricular Electronic supplementary material The online version of this article (

Prognostic insights of molecular imaging in cardiac sarcoidosis

“…Indeed, the association between a high tCMA and RV pathological FDG-uptake should be considered as a significant risk marker in patients with suspected CS. 11 In accordance with these results, Ahmandian et al 14 showed that a high tCMA was an independent predictor of cardiovascular events in CS patients. Similarly, in a recent study by Omote et al, CS patients with RV FDG-uptake showed notably higher cardiac metabolic volume (CMV), total lesion glycolysis (TLG), LV standardized-uptake-value (SUV) max, LV involvement, and cardiac adverse events than those without.…”

“…9 Obtaining a complete FDG-uptake suppression in normal myocardium through dietary protocols permits a more confident diagnosis of cardiac involvement; so it is important to check the rate of cardiac suppression obtained in own Center and modify/ lengthen the dietary protocol, accordingly. Indeed, although several patterns of normal left-ventricular (LV) FDG-uptake have been described, 10,11 non-homogeneous cardiac distribution of radiotracer may rise interpretative doubts; thus, a complete and robust clinical assessment is mandatory to determine the most probable diagnosis. In the current issue of the Journal, Tuominen et al performed a retrospective analysis of 137 patients who underwent 18 F-FDG-PET/CT imaging for suspected CS evaluation.…”

“…In the small group of patients who underwent both PET and CMRI, the positive predictive value of abnormal RV FDG-uptake was higher than the evidence of LGE at CMRI, whereas negative predictive values were similar. 11 The presence of RV FDG-uptake may reflect the spread of CS activity, being a predictor of death 12 or ventricular tachycardia events. 13 In the cohort of Tuominen, cardiac events were not significantly more common in patients with diagnosed CS than those without: unlike RV FDG-uptake, cardiac PET positivity by itself was not predictive of cardiac events, and cardiologists should be aware of this clinical implication.…”

Advanced Imaging in Cardiac Sarcoidosis

“…In the PET study by Tuominen et al, a subset of patients underwent CMR imaging; no adverse events were reported in patents who had no LGE, confirming an excellent negative predictive value of this finding (43).…”

“…Patients with pathologic right ventricular uptake had significantly higher total cardiac metabolic activity than those without right ventricular uptake. Therefore, the combination of pathologic right ventricular uptake and high total cardiac metabolic activity should be considered a significant risk factor in patients with CS (43,44).…”