Imaging Biomarkers in Atherosclerosis Trials

Advantages and Disadvantages Coronary angiography Coronary lumen 0.4 mm Yes Yes Two-dimensional silhouette of lumen only, associated with cardiovascular events, accepted surrogate for expanded indication IVUS Coronary arterial wall 0.08-0.10mm No Yes, catheter Tomographic, volumetric assessment of changes in plaque burden and vascular remodeling with excellent resolution Carotid ultrasound cIMT and plaque 0.15 mm No No Wide availability, wide clinical trial experience, low cost, technically demanding; further validation of 3D plaque assessment required Coronary CT Coronary lumen and wall 0.4 mm Yes No Rapid acquisition, limited image resolution for plaque burden, radiation exposure MRI Carotid lumen and wall 0.5-1.0mm No No Plaque characterization possible, no validation with clinical events PET Metabolic activity in carotids and aorta 4 mm Yes No Limited image resolution, limited ability to visualize coronary arteries, no validation with clinical events OCT Coronary arterial lumen and wall Excellent, 0.01 mm No Yes, catheter Best image resolution, limited depth of view Requires flushing of lumen NIRS Tissue spectral contrast (chemical assessment) 1 mm No Yes, catheter Link to plaque status not clear, images difficult to interpret, limited spatial registration NIR fluorescence Exogenous, molecular contrast 1 mm No Yes, catheter and injection of molecular compound Limited depth of view due to blood absorption, may require flushing; high potential for molecular imaging; depends on targeted compound approval for humans