Author + information
- Received May 1, 2011
- Revision received August 1, 2011
- Accepted August 16, 2011
- Published online January 1, 2012.
- Kelly S. Myers, MD⁎,†,
- James H.F. Rudd, PhD, MD⁎,
- Eric P. Hailman, MD, PhD‡,§,
- James A. Bolognese, MStat‡∥,
- Joanne Burke, MS‡,
- Cathy Anne Pinto, PhD‡,
- Michael Klimas, PhD, MBA‡,
- Richard Hargreaves, PhD‡,
- Hayes M. Dansky, MD‡ and
- Zahi A. Fayad, PhD⁎,⁎ ()
- ↵⁎Reprint requests and correspondence:
Dr. Zahi A. Fayad, Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, Atran BM-24, Box 1234, One Gustave L. Levy Place, New York, New York 10029
Objectives A prospective, multicenter 18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging study was performed to estimate the correlations among arterial FDG uptake and atherosclerotic plaque biomarkers in patients with peripheral artery disease.
Background Inflammation within atherosclerotic plaques is associated with instability of the plaque and future cardiovascular events. Previous studies have shown that 18F-FDG-PET/CT is able to quantify inflammation within carotid artery atherosclerotic plaques, but no studies to date have investigated this correlation in peripheral arteries with immunohistochemical confirmation.
Methods Thirty patients across 5 study sites underwent 18F-FDG-PET/CT imaging before SilverHawk atherectomy (FoxHollow Technologies, Redwood City, California) for symptomatic common or superficial femoral arterial disease. Vascular FDG uptake (expressed as target-to-background ratio) was measured in the carotid arteries and aorta and femoral arteries, including the region of atherectomy. Immunohistochemistry was performed on the excised atherosclerotic plaque extracts, and cluster of differentiation 68 (CD68) level as a measure of macrophage content was determined. Correlations between target-to-background ratio of excised lesions, as well as entire arterial regions, and CD68 levels were determined. Imaging was performed during the 2 weeks before surgery in all cases.
Results Twenty-one patients had adequate-quality 18F-FDG-PET/CT peripheral artery images, and 34 plaque specimens were obtained. No significant correlation between lesion target-to-background ratio and CD68 level was observed.
Conclusions There were no significant correlations between CD68 level (as a measure of macrophage content) and FDG uptake in the peripheral arteries in this multicenter study. Differences in lesion extraction technique, lesion size, the degree of inflammation, and imaging coregistration techniques may have been responsible for the failure to observe the strong correlations with vascular FDG uptake observed in previous studies of the carotid artery and in several animal models of atherosclerosis.
This research was funded by the National Institutes of Health/National Heart, Lung and Blood Institute (NIH/NHLBI R01 HL71021, NIH/NHLBI and the Doris Duke Clinical Research Foundation. R01 HL78667, and NIH/NIBIB R01 EB009638 [to Dr. Fayad]) and by unrestricted research grants from Merck Research Laboratories and FoxHollow Technologies. Dr. Myers was supported by the Doris Duke Charitable Foundation and Dr. Rudd by the NIHR Cambridge Biomedical Research Center and an International Fellowship from the British Heart Foundation. Ms. Burke, Ms. Pinto, Mr. Klimas, Mr. Hargreaves, and Dr. Dansky are associated with Merck Research Laboratories. Dr. Hailman and Mr. Bolognese were associated with Merck Research Laboratories during the research study but are currently associated with Novartis Institutes for Biomedical Research Inc. and Cytel Inc., respectively. H. William Strauss, MD, served as Guest Editor for this paper.
- Received May 1, 2011.
- Revision received August 1, 2011.
- Accepted August 16, 2011.
- American College of Cardiology Foundation