Suppressing physiologic 18-fluorodeoxyglucose uptake in patients undergoing positron emission tomography for cardiac sarcoidosis: The effect of a structured patient preparation protocol.

OBJECTIVE: Myocardial positron emission tomography (PET) to detect cardiac sarcoidosis requires adequate patient preparation; however, in many cases physiologic myocardial 18F-fluorodeoxyglucose (18F-FDG) uptake may not be adequately suppressed. We sought to evaluate the efficacy of a structured patient preparation protocol as recommended by the joint SNMMI/ASNC expert consensus document on the role of 18F-FDG PET/CT in cardiac sarcoid detection and therapy monitoring. The SNMMI/ASNC preparation protocol recommends at least two high-fat (> 35 g), low-carbohydrate (< 3 g) (HFLC) meals the day before testing followed by fasting for at least 4-12 hours. METHODS: All unique PET scans performed for cardiac sarcoidosis before (group 1) and after (group 2) application of the new preparation protocol were included in the study. In group 1, patients were given a preparation protocol of HFLC meals with suggested meals examples, while patients in group 2 received detailed diet instructions, together with accepted and non-accepted meal examples along. In group 2, reinforcement of instructions by nursing staff and review of dietary log were performed prior to testing. All PET images were evaluated for suppression of physiologic myocardial 18F-FDG uptake. RESULTS: Group 1 included 124 unique patients, and group 2 included 232 unique patients. There were no significant differences in baseline patient characteristics between the two groups. Suppression of physiologic myocardial 18F-FDG uptake was achieved in 91% of patients in group 2, compared to 78% of patients in group 1 (P < .001). A "diffuse" myocardial uptake pattern, indicating inadequate 18F-FDG suppression, was seen in 2% of studies in group 2 vs 12% in group 1 (P < .001). CONCLUSION: In this single-center study, application of a structured preparation protocol was highly successful in achieving suppression of physiologic myocardial 18F-FDG uptake in patients undergoing myocardial PET for cardiac sarcoidosis.

Diagnostic and predictive value of speckle tracking echocardiography in cardiac sarcoidosis.

BACKGROUND: Sarcoidosis is a systemic granulomatous disease that may affect the myocardium. This study evaluated the diagnostic and prognostic value of 2-dimensional speckle tracking echocardiography in cardiac sarcoidosis (CS). METHODS: Eighty-three patients with extracardiac, biopsy-proven sarcoidosis and definite/probable diagnosis of cardiac involvement diagnosed from January 2005 through December 2016 were included. Strain parameters in early stages of CS, in a subgroup of 23 CS patients with left ventricular ejection fraction (LVEF) within normal limits (LVEF> 52% for men: > 54% for women, mean value: 57.3% ± 3.8%) and no wall motion abnormalities was compared with 97 controls (1:4) without cardiac disease. LV and right ventricular (RV) global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain and strain rate (SR) analyses were performed with TomTec software and correlated with cardiac outcomes (including heart failure and arrhythmias). This study was approved by the Mayo Clinic Institutional Review Board, and all patients gave informed written consent to participate. RESULTS: Mean age of CS patients was 53.6 ± 10.8 years, and 34.9% were women. Mean LVEF was 43.2% ± 12.4%; LV GLS, - 12.4% ± 3.7%; LV GCS, - 17.1% ± 6.5%; LV GRS, 29.3% ± 12.8%; and RV wall GLS, 14.6% ± 6.3%. In the 23 patients with early stage CS with normal LVEF and RV systolic function, strain parameters were significantly reduced when compared with controls (respectively: LV GLS, - 15.9% ± 2.5% vs - 18.2% ± 2.7% [P = .001]; RV GLS, - 16.9% ± 4.5% vs - 24.1% ± 4.0% [P < .001]). A LV GLS value of - 16.3% provided 82.2% sensitivity and 81.2% specificity for the diagnosis of CS (AUC 0.91), while a RV value of - 19.9% provided 88.1% sensitivity and 86.7% specificity (AUC 0.93). Hospital admission and heart failure significantly correlated to impaired LV GLS (> - 14%). CONCLUSION: Reduced strain values in the LV GLS and RV GLS can be used in the diagnostic algorithm in patients with suspicion of cardiac sarcoidosis. These values also correlate with adverse cardiovascular events.