Feasibility of FDG imaging of the coronary arteries: comparison between acute coronary syndrome and stable angina.
OBJECTIVE
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.


BACKGROUND
Inflammation is known to play an important role in atherosclerosis. Positron emission tomography imaging with (18)F-FDG provides a measure of plaque inflammation.


METHODS
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.


RESULTS
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).


CONCLUSIONS
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.
Rogers
Ian S
IS
Cardiac MR PET CT Program, Division of Cardiology and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Nasir
Khurram
K
Figueroa
Amparo L
AL
Cury
Ricardo C
RC
Hoffmann
Udo
U
Vermylen
David A
DA
Brady
Thomas J
TJ
Tawakol
Ahmed
A
D054058:Acute Coronary Syndrome / Q000000981:diagnostic imaging* / Q000209:etiology; D000368:Aged; D000787:Angina Pectoris / Q000000981:diagnostic imaging* / Q000209:etiology; D000789:Angina, Unstable / Q000000981:diagnostic imaging* / Q000209:etiology; D001011:Aorta / Q000000981:diagnostic imaging; D015415:Biomarkers / Q000097:blood; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed
D015415:Biomarkers; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18