Demeure, Fabian
[UCL]
Hanin, François-Xavier
[UCL]
Bol, Anne
[UCL]
Sprimont, Pierre
[UCL]
Vincent, Marie-Françoise
[UCL]
Gerber, Bernhard
[UCL]
Pasquet, Agnes
[UCL]
Vanoverschelde, Jean-Louis
[UCL]
Vancraeynest, David
[UCL]
Background: 18F-FDG PET/CT is a promising method for imaging coronary atherosclerotic plaque inflammation. However, the avid myocardial glucose uptake may preclude the correct visualization of coronary arteries. The Randle cycle (fatty acid - glucose cycle competition) establishes that fatty acid loading suppresses glucose metabolism by the myocardium. Aim: We hypothesized that circulating free fatty acid (FFA) levels might predict the magnitude of myocardial FDG-uptake suppression. Methods: 36 healthy volunteers underwent cardiac PET/CT (Philips Gemini-TF) after overnight fasting preceded by a high fat-low carbohydrate meal. A 5 minutes per bed position image of the heart was obtained 60 minutes after injection of 370 MBq of 18F-FDG. Myocardial uptake suppression was assessed by using a qualitative visual scale (QVS) while maximum standardized uptake value (SUVmax) of the left ventricle was measured at the level of the papillary muscles. Both parameters were correlated to insulin, glucose and FFA levels measured immediately before, and respectively 1 and 2 hours post injection. Results: Mean glycemia was 81.5±4.1 mg/dL, mean insulin level was 6.0±4.1 UI/L, mean FFA was 0.72±0.30 mmol/L before FDG injection. The mean glycemia and insulin level decreased and the mean FFA increased over time. By QVS, background suppression was optimal in 24 subjects (mean SUVmax 2.11±0.41) and suboptimal in 12 (mean SUVmax 7.37±4.20), the mean myocardial SUVmax being significantly lower in the first group (p<0.001). We note a good correlation between the FFA level and the reciprocal of SUVmax (R = 0.59). Furthermore, the amount of FFA was higher in volunteers with a good suppression compared with volunteers with a poor suppression (0.81±0.31 vs. 0.53±0.14 mmol/L; p=0.005). The ROC curve analysis identified 0.65 mmol/L as the cut-off value with the best positive predictive value (88%). However no correlation existed between glycemia or insulin level and the reciprocal of SUVmax (R = -0.25 and 0,02 respectively). There was no difference in glycemia or insulin level between volunteers with a good or poor suppression. Conclusion: Myocardial FDG-uptake suppression is inversely correlated with FFA level and is significantly better in volunteers with high FFA level. The measurement of FFA at the time of 18F-FDG injection represents an interesting way for predicting the quality of myocardial FDG-uptake suppression.


Bibliographic reference |
Demeure, Fabian ; Hanin, François-Xavier ; Bol, Anne ; Sprimont, Pierre ; Vincent, Marie-Françoise ; et. al. Circulating free fatty acid levels predict the myocardial FDGuptake suppression. Implications for vulnerable plaque imaging..Annual Congress of the European Association of Nuclear Medicine (Lyon, du 19/10/2013 au 23/10/2013). |
Permanent URL |
http://hdl.handle.net/2078.1/138483 |