Direct Comparison of Virtual-Histology Intravascular Ultrasound and Optical Coherence Tomography Imaging for Identification of Thin-Cap Fibroatheroma.
Obaid, Daniel R
Parker, Richard A
Calvert, Patrick A
Hoole, Stephen P
West, Nick EJ
VH-IVUS and OCT identification of TCFA
Circ Cardiovasc Imaging
Ovid Technologies (Wolters Kluwer Health)
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Brown, A., Obaid, D. R., Costopoulos, C., Parker, R. A., Calvert, P. A., Teng, Z., Hoole, S. P., et al. (2015). Direct Comparison of Virtual-Histology Intravascular Ultrasound and Optical Coherence Tomography Imaging for Identification of Thin-Cap Fibroatheroma.. Circ Cardiovasc Imaging, 8 (e003487) https://doi.org/10.1161/CIRCIMAGING.115.003487
BACKGROUND: Although rupture of thin-cap fibroatheroma (TCFA) underlies most myocardial infarctions, reliable TCFA identification remains challenging. Virtual-histology intravascular ultrasound (VH-IVUS) and optical coherence tomography (OCT) can assess tissue composition and classify plaques. However, direct comparisons between VH-IVUS and OCT are lacking and it remains unknown whether combining these modalities improves TCFA identification. METHODS AND RESULTS: Two hundred fifty-eight regions-of-interest were obtained from autopsied human hearts, with plaque composition and classification assessed by histology and compared with coregistered ex vivo VH-IVUS and OCT. Sixty-seven regions-of-interest were classified as fibroatheroma on histology, with 22 meeting criteria for TCFA. On VH-IVUS, plaque (10.91±4.82 versus 8.42±4.57 mm(2); P=0.01) and necrotic core areas (1.59±0.99 versus 1.03±0.85 mm(2); P=0.02) were increased in TCFA versus other fibroatheroma. On OCT, although minimal fibrous cap thickness was similar (71.8±44.1 μm versus 72.6±32.4; P=0.30), the number of continuous frames with fibrous cap thickness ≤85 μm was higher in TCFA (6.5 [1.75-11.0] versus 2.0 [0.0-7.0]; P=0.03). Maximum lipid arc on OCT was an excellent discriminator of fibroatheroma (area under the curve, 0.92; 95% confidence interval, 0.87-0.97) and TCFA (area under the curve, 0.86; 95% confidence interval, 0.81-0.92), with lipid arc ≥80° the optimal cut-off value. Using existing criteria, the sensitivity, specificity, and diagnostic accuracy for TCFA identification was 63.6%, 78.1%, and 76.5% for VH-IVUS and 72.7%, 79.8%, and 79.0% for OCT. Combining VH-defined fibroatheroma and fibrous cap thickness ≤85 μm over 3 continuous frames improved TCFA identification, with diagnostic accuracy of 89.0%. CONCLUSIONS: Both VH-IVUS and OCT can reliably identify TCFA, although OCT accuracy may be improved using lipid arc ≥80° and fibrous cap thickness ≤85 μm over 3 continuous frames. Combined VH-IVUS/OCT imaging markedly improved TCFA identification.
Atherosclerosis, Intravascular ultrasound, Coronary artery disease
This study was funded by grants from the British Heart Foundation (FS/13/33/30168), Heart Research UK (RG2638/14/16), the Cambridge NIHR Biomedical Research Centre, and the BHF Cambridge Centre for Research Excellence.
British Heart Foundation (None)
British Heart Foundation (FS/15/26/31441)
External DOI: https://doi.org/10.1161/CIRCIMAGING.115.003487
This record's URL: https://www.repository.cam.ac.uk/handle/1818/250368
Creative Commons Attribution 4.0
Licence URL: http://creativecommons.org/licenses/by/4.0/