Feasibility of FDG Imaging of the Coronary Arteries Comparison Between Acute Coronary Syndrome and Stable Angina

Harvard University, Cambridge, Massachusetts, United States
JACC. Cardiovascular imaging (Impact Factor: 7.19). 04/2010; 3(4):388-97. DOI: 10.1016/j.jcmg.2010.01.004
Source: PubMed


This study tested the hypothesis that fluorodeoxyglucose (FDG) uptake within the ascending aorta and left main coronary artery (LM), measured using positron emission tomography (PET), is greater in patients with recent acute coronary syndrome (ACS) than in patients with stable angina.
Inflammation is known to play an important role in atherosclerosis. Positron emission tomography imaging with (18)F-FDG provides a measure of plaque inflammation.
Twenty-five patients (mean age 57.9 +/- 9.8 years, 72% male, 10 ACS, and 15 stable angina) underwent cardiac computed tomographic angiography and PET imaging with (18)F-FDG after invasive angiography. Images were coregistered, and FDG uptake was measured at locations of interest for calculation of target-to-background ratios (TBR). Additionally, FDG uptake was measured at the site of the lesion deemed clinically responsible for the presenting syndrome (culprit) by virtue of locating the stent deployed to treat the syndrome.
The FDG uptake was higher in the ACS versus the stable angina groups in the ascending aorta (median [interquartile ranges] TBR 3.30 [2.69 to 4.12] vs. 2.43 [2.00 to 2.86], p = 0.02), as well as the LM (2.48 [2.30 to 2.93] vs. 2.00 [1.71 to 2.44], p = 0.03, respectively). The TBR was greater for culprit lesions associated with ACS than for lesions stented for stable coronary syndromes (2.61 vs. 1.74, p = 0.02). Furthermore, the TBR in the stented lesions (in ACS and stable angina groups) correlated with C-reactive protein (r = 0.58, p = 0.04).
This study shows that in patients with recent ACS, FDG accumulation is increased both within the culprit lesion as well as in the ascending aorta and LM. This observation suggests inflammatory activity within atherosclerotic plaques in acute coronary syndromes and supports intensification of efforts to refine PET methods for molecular imaging of coronary plaques.

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Available from: Ricardo C Cury, Sep 07, 2015
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    • "Coronary imaging remains challenging with PET or other currently available imaging modalities due to small size, constant motion, and in the case of 18F-FDG, obscuring uptake by adjacent myocardium [14]. Although 18F-FDG uptake is a marker for viable myocardium, this myocardial uptake makes it harder to image the adjacent small-sized coronaries [32], though there are some promising initial results [33]. This makes an intravascular imaging approach advantageous, minimizing the distance and maximizing the sensitivity to coronary plaque signal. "
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