Search

Aims Previous studies have reported the safety and feasibility of both time-domain optical coherence tomography (TD-OCT) and Fourier-domain OCT (FD-OCT) in highly selected patients and clinical settings. However, the generalizability of these data is limited, and data in unselected patient populations reflecting a routine cathlab practice are lacking. We compared safety of intracoronary FD-OCT imaging to intravascular ultrasound (IVUS) imaging in a large real-world series of consecutive patients who underwent invasive imaging during coronary catheterization in our centre. Methods and results This is a prospective, single-centre registry of patients scheduled for coronary angiography or intervention undergoing intracoronary imaging with FD-OCT or IVUS between April 2008 and December 2013. Intra-procedural and major inhospital adverse events that could be possibly related to invasive imaging were registered routinely by the operator as part of our clinical report and prospectively recorded in our database. These events were retrospectively individually adjudicated by an independent safety committee. Between April 2008 and December 2013,13 418 diagnostic or interventional coronary catheterization procedures were performed. Of these, 1142 procedures used OCT and 2476 procedures used IVUS. Invasive imaging-related complications were rare, did not differ between the two imaging methods (OCT: n = 7, 0.6%; IVUS: n = 12, 0.5%; P = 0.6), and were self-limiting after retrieval of the imaging catheter or easily treatable in the catheterization laboratory. No major adverse events, prolongation of hospital stay, or permanent patient harm was observed. Conclusion FD-OCT is safe in an unselected and heterogeneous group of patients with varying clinical settings. [ABSTRACT FROM AUTHOR]

Aims: Previous studies have reported the safety and feasibility of both time-domain optical coherence tomography (TD-OCT) and Fourier-domain OCT (FD-OCT) in highly selected patients and clinical settings. However, the generalizability of these data is limited, and data in unselected patient populations reflecting a routine cathlab practice are lacking. We compared safety of intracoronary FD-OCT imaging to intravascular ultrasound (IVUS) imaging in a large real-world series of consecutive patients who underwent invasive imaging during coronary catheterization in our centre., Methods and Results: This is a prospective, single-centre registry of patients scheduled for coronary angiography or intervention undergoing intracoronary imaging with FD-OCT or IVUS between April 2008 and December 2013. Intra-procedural and major in-hospital adverse events that could be possibly related to invasive imaging were registered routinely by the operator as part of our clinical report and prospectively recorded in our database. These events were retrospectively individually adjudicated by an independent safety committee. Between April 2008 and December 2013, 13 418 diagnostic or interventional coronary catheterization procedures were performed. Of these, 1142 procedures used OCT and 2476 procedures used IVUS. Invasive imaging-related complications were rare, did not differ between the two imaging methods (OCT: n = 7, 0.6%; IVUS: n = 12, 0.5%; P = 0.6), and were self-limiting after retrieval of the imaging catheter or easily treatable in the catheterization laboratory. No major adverse events, prolongation of hospital stay, or permanent patient harm was observed., Conclusion: FD-OCT is safe in an unselected and heterogeneous group of patients with varying clinical settings., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Aims: Qualitative criteria for plaque tissue characterisation by OCT are well established, but quantitative methods lack systematic validation in vivo. High optical attenuation coefficient µt has been associated with unstable plaque features, such as lipid core. The purpose of this study was to validate optical coherence tomography (OCT) attenuation imaging for tissue characterisation in vivo, specifically to detect lipid core in coronary atherosclerotic plaques, and to evaluate quantitatively the ability of OCT attenuation imaging to differentiate thin-cap (TCFA) and thick-cap fibroatheroma (FA)., Methods and Results: We prospectively enrolled 85 patients undergoing imaging of a native coronary segment by both OCT and near-infrared spectroscopy and intravascular ultrasound (NIRS-IVUS). Ninety-eight NIRS-positive 4 mm plaque segments were selected and matched to the OCT data. Two experienced OCT readers classified the plaque type using OCT criteria. A cap thickness of 65 μm was used to differentiate TCFA and FA. We computed an index of plaque attenuation (IPA) in the 4 mm blocks, and assessed the association of this index with plaque type. IPA differentiated between TCFA and FA (AUC=0.82 in ROC analysis; p<0.0001). LCBI was numerically, but not significantly, higher in TCFA compared to FA (p=0.097)., Conclusions: IPA is an unbiased reproducible measure of tissue optical properties. The fraction of pixels with attenuation coefficient ≥11 mm-1 can identify TCFA.

High resolution, 100 frames/sec intravascular optical coherence tomography (IVOCT) can distinguish plaque types, but further validation is needed, especially for automated plaque characterization. We developed experimental and 3D registration methods, to provide validation of IVOCT pullback volumes using microscopic, brightfield and fluorescent cryo-image volumes, with optional, exactly registered cryo-histology. The innovation was a method to match an IVOCT pull-back images, acquired in the catheter reference frame, to a true 3D cryo-image volume. Briefly, an 11-parameter, polynomial virtual catheter was initialized within the cryo-image volume, and perpendicular images were extracted, mimicking IVOCT image acquisition. Virtual catheter parameters were optimized to maximize cryo and IVOCT lumen overlap. Local minima were possible, but when we started within reasonable ranges, every one of 24 digital phantom cases converged to a good solution with a registration error of only +1.34±2.65μm (signed distance). Registration was applied to 10 ex-vivo cadaver coronary arteries (LADs), resulting in 10 registered cryo and IVOCT volumes yielding a total of 421 registered 2D-image pairs. Image overlays demonstrated high continuity between vascular and plaque features. Bland-Altman analysis comparing cryo and IVOCT lumen area, showed mean and standard deviation of differences as 0.01±0.43 mm 2 . DICE coefficients were 0.91±0.04. Finally, visual assessment on 20 representative cases with easily identifiable features suggested registration accuracy within one frame of IVOCT (±200μm), eliminating significant misinterpretations introduced by 1mm errors in the literature. The method will provide 3D data for training of IVOCT plaque algorithms and can be used for validation of other intravascular imaging modalities.

Aims: In coronary bifurcations assessment, evaluation of side-branch (SB) ostia by an optical coherence tomography (OCT) pullback performed in the main branch (MB) could speed up lesion evaluation and minimize contrast volume. Dedicated software that reconstructs the cross-sections perpendicular to the SB centreline could improve this assessment. We aimed to validate a new method for assessing the SB ostium from an OCT pullback performed in the MB., Methods and Results: Thirty-one sets of frequency-domain OCT pullbacks from 28 patients, both from the MB and the SB of a coronary artery bifurcation were analysed. Measurements of the SB ostium from the SB pullback were used as a reference. Measurements of the SB ostium from the MB pullback were then performed in a laboratory setting by (i) conventional analysis and (ii) cut-plane analysis, and the measurement error for each analysis was estimated. Correlations of SB ostium measurements acquired from the MB pullback in comparison with reference measurements acquired from the SB pullback were higher with cut-plane analysis compared with conventional analysis, albeit not reaching statistical significance (area: rcut-plane = 0.927 vs. rconventional = 0.870, P = 0.256; mean diameter: rcut-plane = 0.918 vs. rconventional = 0.788, P = 0.056; minimum diameter: rcut-plane = 0.841 vs. rconventional = 0.812, P = 0.734; maximum diameter: rcut-plane = 0.770 vs. rconventional = 0.635, P = 0.316). Cut-plane analysis was associated with lower absolute error than conventional analysis (area: 0.56 ± 0.45, vs. 1.50 ± 1.31 mm(2), P < 0.001; mean diameter: 0.18 ± 0.14 vs. 0.44 ± 0.30 mm, P < 0.001)., Conclusion: Measurements of SB ostium performed in a laboratory setting by cut-plane analysis of an OCT pullback of the main branch have high correlation with reference measurements performed in a SB OCT pullback and lower error compared with conventional analysis., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

Various fully bioresorbable stents (BRS) have been recently developed, allowing for temporary scaffolding of the vessel wall. The potentially unique advantage of BRS to temporary scaffold the vessel could reduce the risk of adverse clinical outcomes caused by acute vessel geometry changes, late malapposition, jailed side branches or inflexibility of permanent stents. The design of BRS is, however, not similar for all stents, resulting in differences in degradation and behaviour. To assess the performance of BRS, the effect of degradation and behaviour on the vessel wall should be accurately evaluated. Intracoronary imaging techniques such as intravascular ultrasound (IVUS), optical coherence tomography (OCT) and near-infrared spectroscopy (NIRS) allow for detailed longitudinal evaluation of the stent and the vessel wall and might therefore aid in improving design and behaviour of BRS., Competing Interests: Disclosure: The authors have no conflicts of interest to declare.