Predictors of F-18-sodiumfluoride uptake in patients with stable coronary artery disease and adverse plaque features on computed tomography angiography

Abstract

Aims In patients with stable coronary artery disease (CAD) and high-risk plaques (HRPs) on coronary computed tomography angiography (CTA), we sought to define qualitative and quantitative CTA predictors of abnormal coronary F-18-sodium fluoride uptake (F-18-NaF) by positron emission tomography (PET). Methods and results Patients undergoing coronary CTA were screened for HRP. Those who presented with >= 3 CTA adverse plaque features (APFs) including positive remodelling; low attenuation plaque (LAP, <30 HU), spotty calcification; obstructive coronary stenosis >= 50%; plaque volume >100 mm3 were recruited for F-18-NaF PET. In lesions with stenosis >= 25%, quantitative plaque analysis and maximum F-18-NaF target to background ratios (TBRs) were measured. Of 55 patients, 35 (64%) manifested coronary F-18-NaF uptake. Of 68 high-risk lesions 49 (70%) had increased PET tracer activity. Of the APFs, LAP had the highest sensitivity (39.4%) and specificity (98.3%) for predicting F-18-NaF uptake. TBR values were higher in lesions with LAP compared to those without [1.6 (1.3-1.8) vs. 1.1 (1.0-1.3), P= 0.01]. On adjusted multivariable regression analysis, LAP (both qualitative and quantitative) was independently associated with plaque TBR [LAP qualitative: beta = 0.47, 95% confidence interval (CI) 0.30-0.65; P< 0.001] and (LAP volume: beta = 0.20 per 10 mm(3), 95% CI 0.13-0.27; P< 0.001). Conclusion In stable CAD patients with HRP, LAP is predictive of F-18-NaF coronary uptake, but F-18-NaF is often seen in the absence of LAP. If F-18-NaF uptake is shown to be associated with adverse outcomes and becomes clinically used, the presence of LAP may define patients who would not benefit from the added testing.