Carotid 18FDG-PET uptake independently predicts non-obstructive coronary artery disease as evaluated by CT coronary angiography

Objectives To evaluate if FDG-PET uptake, a measure of carotid wall inflammation (CWI) was predictive of early coronary artery disease (CAD) as revealed by CT coronary angiography (CTA).

Methods 34 patients with known or suspected cardiovascular disease prospectively underwent FDG-PET imaging for evaluation of CWI and CTA imaging of the coronaries. Different degrees of CWI as depicted by continuous and several increasingly classified FDG target-to-background-ratios (TBRmax 1.6-2.4) as well as TBRmax of most diseased segments (MDS 1.6-2.4) of carotids were identified. Degree of CAD was classified as none, non-obstructive or obstructive CAD, respectively. Multivariate regression models of several cardiovascular risk factors and PET methodology related variables including continuous and classified TBRmax and MDS values were performed to identify potential predictors of non-obstructive CAD.

Results Carotid TBRmax >2.0 (Odds ratio (OR) 7.0, p=0.032) and >2.2 (OR 13.6, p=0.005), and MDS values >2.4 (OR 10.7, p=0.025) independently predicted non-obstructive CAD.

Conclusions CWI as depicted by FDG-PET imaging independently predicted non-obstructive as opposed to obstructive CAD, but none of the clinical cardiovascular risk factors did. Based on a carotid FDG uptake cut-off of at least 2.0, patients at risk for non-obstructive CAD might be identifiable. Therefore, carotid FDG-PET might serve as a noninvasive imaging tool to identify patients with early CAD until direct PET imaging of the coronaries is available