Abstract 19845: Identifying Advanced Coronary Atherosclerotic Plaques: An Ex Vivo Study Using Computed Tomography and Intravascular Ultrasound
Introduction: We assessed the ability of CT, and IVUS to differentiate between early and advanced coronary atherosclerotic plaques as defined by histopathology.
Methods: Nine coronaries of three ex vivo donor hearts were imaged, while preserving the physiological shape of the hearts. For CT scanning (GE, High Definition CT, inplane resolution 0.23x0.23 mm2) the right and left coronary arteries were canulated and filled with iodinated methylcellulose solution. During the IVUS (Boston Scientific, Galaxy) imaging the vessels were perfused with saline. The histological preparation was performed after pressure formalin fixation. Histological sections with an increment of one-millimeter were co-registered with CT and IVUS and analyzed randomly. Adaptive intimal thickening, pathological intimal thickening, fibrous plaque were considered as early plaques; early fibroatheroma, late fibroatheroma, and thin cap fibroatheroma as advanced plaques. We assessed 379 CT and 293 IVUS cross-sections using standard plaque composition categories (CT: non-calcified, mixed, calcified; IVUS: normal, fibrotic, soft, mixed [i.e., fibrofatty, fibrocalcific, fattycalcific], calcified).
Results: Of the 379 histology cross sections with plaque, 76.5 % were classified as early and 23.5 % as advanced plaque. The overall inter-reader agreement to classify plaque by composition was excellent for CT (Cohen's kappa = 0.87) and good for IVUS (Cohen's kappa: 0.77). In CT, the absence of plaque and the presence of mixed plaque were significantly different between early and advanced plaque based on histopathology (p<0.001). Advanced plaque was detected only in 6% of the normal CT cross-sections. In IVUS, the presence of fibrofatty and fibrocalcific plaques was significantly different between histopathological slides containing early and advanced plaque (both, p<0.01). Overall, IVUS but not CT based plaque composition features were significantly different between early and advanced plaques (p<0.01 and p=0.052; respectively).
Conclusions: Traditional assessment of plaque composition by IVUS and high resolution CT demonstrated limited capability to predict the presence of early versus advanced coronary atherosclerotic plaque as defined by histopathology.
- © 2010 by American Heart Association, Inc.