Circulation: FDG PET can mark atherosclerotic activity, drug effectiveness

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Researchers from Mount Sinai School of Medicine in New York City have used FDG PET to better understand the relationship between atherosclerotic plaque inflammation, calcification, serum biomarkers and vascular risk factors.

James H.F. Rudd, MD, and colleagues studied 41 subjects who underwent vascular PET/CT imaging with FDG. All had either vascular disease or multiple risk factors for it. The study was published online before print Jan. 26, in Circulation: Cardiovascular Imaging.

Not all subjects had the same vascular territories imaged: 40 underwent carotid imaging, 27 aortic, 24 iliac and 13 femoral imaging. In addition, 33 subjects had a panel of biomarkers analyzed.

The investigators found strong associations between FDG uptake in neighboring arteries (left vs. right carotid, ascending aorta vs. aortic arch). They also found that calcification and inflammation rarely overlapped within arteries—based on FDG uptake versus the calcium score

Carotid artery FDG uptake was greater in those with a history of coronary artery disease and in males versus females. Researchers noted similar findings in the aorta and iliac arteries.

Subjects with the highest levels of FDG uptake also had the greatest concentrations of inflammatory biomarkers: descending aorta versus matrix metalloproteinase (MMP) 3and carotid versus MMP 9. Researchers observed non-significant positive trends between FDG uptake and levels of interleukin 18, fibrinogen and C-reactive protein.

Rudd, and colleagues also found that the atheroprotective biomarker adiponectin was negatively correlated with the degree of arterial inflammation in the descending aorta.

“Plaque inflammation and calcification rarely overlap, supporting the theory that calcification represents a late, burnt-out stage of atherosclerosis. Inflammation in one arterial territory is associated with inflammation elsewhere, and the degree of local arterial inflammation is reflected in the blood levels of several circulating biomarkers,” they concluded.

They suggested that FDG PET imaging be used as a surrogate marker of both atherosclerotic disease activity and drug effectiveness and noted that prospective, event-driven studies are underway to determine the role of this technique in clinical risk prediction.