18F-Sodium fluoride uptake is associated with severity of atherosclerotic stenosis in stable ischemic heart disease.

BACKGROUND: Increased uptake of 18F-Sodium fluoride (18F-NaF) PET has potential to identify atherosclerotic plaques that are vulnerable to rupture. Whether 18F-NaF PET can evaluate the significance of atherosclerotic plaque in patients with stable coronary artery disease is less clear. We evaluated 18F-NaF PET uptake in coronary arteries in patients without acute coronary artery syndrome to determine the association of 18F-NaF signal uptake with severity of coronary stenosis. METHODS AND RESULTS: We retrospectively identified 114 patients who received both regadenoson stress 82Rb myocardial perfusion PET and 18F-NaF PET study with an average interval of 5 months. Out of this cohort, forty-one patients underwent invasive coronary angiography. In a patient-based analysis, patients with ischemic regadenoson stress 82Rb PET had significantly higher coronary 18F-NaF uptake than patients with normal myocardial perfusion (P < .01). Among the 41 patients who underwent coronary angiography, per-vessel 18F-NaF uptake in both obstructive and nonobstructive coronary arteries was significantly higher than in normal coronary arteries (P < .05) regardless of the severity of coronary calcification. There was poor correlation between calcification and 18F-NaF uptake in coronary arteries (r = 0.41) CONCLUSION: Coronary arterial 18F-NaF uptake is associated with coronary stenosis severity in patients with stable coronary artery disease. 18F-NaF PET studies may be useful for characterizing coronary atherosclerotic plaques.

A mechanistic model for drug release from PLGA-based drug eluting stent: A computational study.

Atherosclerosis in the coronary artery is one of the leading causes of death in the world. The stenting as a minimally invasive technique was considered as an effective tool to reduce the severity of atherosclerotic stenosis. In-stent restenosis is the main drawback of the stenting in the coronary artery. Understanding the mechanism of drug release from drug-eluting stents and drug uptake in the arterial wall and obtaining more information about their functionality using mathematical modeling and numerical simulation, could be considered as a predictive tool to investigate in-stent restenosis growth which is experimentally expensive to study. In this work, the local delivery of a therapeutic agent from a PLGA-based bioabsorbable stent implanted in a coronary artery to predict the drug release as well as spatio-temporal drug distribution in a coronary artery with a vulnerable plaque is mathematically modeled and numerically simulated. The effect of copolymer ratio on drug release has been also investigated.