Coronary 18F-sodium fluoride PET detects high-risk plaque features on optical coherence tomography and CT-angiography in patients with acute coronary syndrome.
Majeed K., Bellinge JW., Butcher SC., Alcock R., Spiro J., Playford D., Hillis GS., Newby DE., Mori TA., Francis R., Schultz CJ.
BACKGROUND AND AIMS: 18F-Sodium Fluoride Positron Emission Tomography (18F-NaF PET) non-invasively detects micro-calcification activity, the earliest stage of atherosclerotic arterial calcification. We studied the association between coronary 18F-NaF uptake and high-risk plaque features on intra-coronary optical coherence tomography (OCT) and CT-angiography (CTCA) and the potential application to patient-level risk stratification. METHODS: Sixty-two prospectively recruited patients with acute coronary syndrome (ACS) underwent multi-vessel OCT, 18F-NaF PET and CTCA. The maximum tissue to background ratio (TBRmax = standardised uptake value (SUV)max/SUVbloodpool) was measured in each coronary segment on 18F-NaF PET scans. High-risk plaque features on OCT and CTCA were compared in matched coronary segments. The number of patients testing positive (>2SD above the normal range) for micro-calcification activity was determined. RESULTS: In 62 patients (age, mean ± standard deviation (SD) = 61 ± 9 years, 85% male) the coronary segments with elevated 18F-NaF uptake had higher lipid arc (LA) (median [25th-75th centile]: 74° [35°-117°] versus 48° [15°-83°], p=0.021), higher prevalence of macrophages [n(%): 37 (62%) versus 89 (39%), p=0.008] and lower plaque free wall (PFW) (50° [7°-110°] versus 94° [34°-180°], p=0.027) on OCT, and a higher total plaque burden (p=0.011) and higher dense calcified plaque burden (p= 0.001) on CTCA, when compared with 18F-NaF negative segments. Patients grouped by increasing number of coronary lesions positive for microcalcification activity (0,1, ≥2) showed decreasing plaque free wall, increasing calcification and increasing macrophages on OCT (respectively p=0.008, p