Vascular Positron Emission Tomography and Restenosis in Symptomatic Peripheral Arterial Disease: A Prospective Clinical Study

Abstract Objectives This study determined whether in vivo positron emission tomography (PET) of arterial inflammation ( 18 F-fluorodeoxyglucose [ 18 F-FDG]) or microcalcification ( 18 F-sodium fluoride [ 18 F-NaF]) could predict restenosis following PTA. Background Restenosis following lower limb percutaneous transluminal angioplasty (PTA) is common, unpredictable, and challenging to treat. Currently, it is impossible to predict which patient will suffer from restenosis following angioplasty. Methods In this prospective observational cohort study, 50 patients with symptomatic peripheral arterial disease underwent 18 F-FDG and 18 F-NaF PET/computed tomography (CT) imaging of the superficial femoral artery before and 6 weeks after angioplasty. The primary outcome was arterial restenosis at 12 months. Results Forty subjects completed the study protocol with 14 patients (35%) reaching the primary outcome of restenosis. The baseline activities of femoral arterial inflammation ( 18 F-FDG tissue-to-background ratio [TBR] 2.43 [interquartile range (IQR): 2.29 to 2.61] vs . 1.63 [IQR: 1.52 to 1.78]; p  18 F-NaF TBR 2.61 [IQR: 2.50 to 2.77] vs . 1.69 [IQR: 1.54 to 1.77]; p  18 F-FDG (cut-off TBR max value of 1.98) and 18 F-NaF (cut-off TBR max value of 2.11) uptake demonstrated excellent discrimination in predicting 1-year restenosis (Kaplan Meier estimator, log-rank p  Conclusions Baseline and persistent femoral arterial inflammation and micro-calcification are associated with restenosis following lower limb PTA. For the first time, we describe a method of identifying complex metabolically active plaques and patients at risk of restenosis that has the potential to select patients for intervention and to serve as a biomarker to test novel interventions to prevent restenosis.