Publications by authors named "Giovanni J Ughi"

36 Publications

Transvascular in vivo microscopy of the subarachnoid space.

J Neurointerv Surg 2022 May 3;14(5). Epub 2022 Feb 3.

New England Center for Stroke Research, Department of Radiology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA

Background: The micro-architectonics of the subarachnoid space (SAS) remain partially understood and largely ignored, likely the result of the inability to image these structures in vivo. We explored transvascular imaging with high-frequency optical coherence tomography (HF-OCT) to interrogate the SAS.

Methods: In vivo HF-OCT was performed in 10 dogs in both the posterior and anterior cerebral circulations. The conduit vessels used were the basilar, anterior spinal, and middle and anterior cerebral arteries through which the perivascular SAS was imaged. The HF-OCT imaging probe was introduced via a microcatheter and images were acquired using a contrast injection (3.5 mL/s) for blood clearance. Segmentation and three-dimensional rendering of HF-OCT images were performed to study the different configurations and porosity of the subarachnoid trabeculae (SAT) as a function of location.

Results: Of 13 acquisitions, three were excluded due to suboptimal image quality. Analysis of 15 locations from seven animals was performed showing six distinct configurations of arachnoid structures in the posterior circulation and middle cerebral artery, ranging from minimal presence of SAT to dense networks and membranes. Different locations showed predilection for specific arachnoid morphologies. At the basilar bifurcation, a thick, fenestrated membrane had a unique morphology. SAT average thickness was 100 µm and did not vary significantly based on location. Similarly, the porosity of the SAT averaged 91% and showed low variability.

Conclusion: We have demonstrated the feasibility to image the structures of the SAS with transvascular HF-OCT. Future studies are planned to further map the SAT to increase our understanding of their function and possible impact on neurovascular pathologies.
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http://dx.doi.org/10.1136/neurintsurg-2021-018544DOI Listing
May 2022

Highly Selective PPARα (Peroxisome Proliferator-Activated Receptor α) Agonist Pemafibrate Inhibits Stent Inflammation and Restenosis Assessed by Multimodality Molecular-Microstructural Imaging.

J Am Heart Assoc 2021 10 11;10(20):e020834. Epub 2021 Oct 11.

Cardiovascular Research CenterCardiology DivisionMassachusetts General HospitalHarvard Medical School Boston MA.

BACKGROUND New pharmacological approaches are needed to prevent stent restenosis. This study tested the hypothesis that pemafibrate, a novel clinical selective PPARα (peroxisome proliferator-activated receptor α) agonist, suppresses coronary stent-induced arterial inflammation and neointimal hyperplasia. METHODS AND RESULTS Yorkshire pigs randomly received either oral pemafibrate (30 mg/day; n=6) or control vehicle (n=7) for 7 days, followed by coronary arterial implantation of 3.5 × 12 mm bare metal stents (2-4 per animal; 44 stents total). On day 7, intracoronary molecular-structural near-infrared fluorescence and optical coherence tomography imaging was performed to assess the arterial inflammatory response, demonstrating that pemafibrate reduced stent-induced inflammatory protease activity (near-infrared fluorescence target-to-background ratio: pemafibrate, median [25th-75th percentile]: 2.8 [2.5-3.3] versus control, 4.1 [3.3-4.3], =0.02). At day 28, animals underwent repeat near-infrared fluorescence-optical coherence tomography imaging and were euthanized, and coronary stent tissue molecular and histological analyses. Day 28 optical coherence tomography imaging showed that pemafibrate significantly reduced stent neointima volume (pemafibrate, 43.1 [33.7-54.1] mm versus control, 54.2 [41.2-81.1] mm; =0.03). In addition, pemafibrate suppressed day 28 stent-induced cellular inflammation and neointima expression of the inflammatory mediators TNF-α (tumor necrosis factor-α) and MMP-9 (matrix metalloproteinase 9) and enhanced the smooth muscle differentiation markers calponin and smoothelin. In vitro assays indicated that the STAT3 (signal transducer and activator of transcription 3)-myocardin axes mediated the inhibitory effects of pemafibrate on smooth muscle cell proliferation. CONCLUSIONS Pemafibrate reduces preclinical coronary stent inflammation and neointimal hyperplasia following bare metal stent deployment. These results motivate further trials evaluating pemafibrate as a new strategy to prevent clinical stent restenosis.
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http://dx.doi.org/10.1161/JAHA.121.020834DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8751880PMC
October 2021

Optical Coherence Tomography for Neurovascular Disorders.

Neuroscience 2021 10 12;474:134-144. Epub 2021 Jun 12.

University of Massachusetts Medical School, Radiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, United States. Electronic address:

Diagnosis of cerebrovascular disease includes vascular neuroimaging techniques such as computed tomography (CT) angiography, magnetic resonance (MR) angiography (with or without use of contrast agents) and catheter digital subtraction angiography (DSA). These techniques provide mostly information about the vessel lumen. Vessel wall imaging with MR seeks to characterize cerebrovascular pathology, but with resolution that is often insufficient for small lesions. Intravascular imaging techniques such as ultrasound and optical coherence tomography (OCT), used for over a decade in the peripheral circulation, is not amendable to routine deployment in the intracranial circulation due to vessel caliber and tortuosity. However, advances in OCT technology including the probe profile, stiffness and unique distal rotation solution, holds the promise for eventual translation of OCT into the clinical arena. As such, it is apropos to review this technology and present the rationale for utilization of OCT in the cerebrovasculature.
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http://dx.doi.org/10.1016/j.neuroscience.2021.06.008DOI Listing
October 2021

High-resolution image-guided WEB aneurysm embolization by high-frequency optical coherence tomography.

J Neurointerv Surg 2021 Jul 28;13(7):669-673. Epub 2020 Sep 28.

Department of Radiology, New England Center for Stroke Research, University of Massachusetts Medical School, Worcester, Massachusetts, USA.

Background: High-frequency optical coherence tomography (HF-OCT) is an intra-vascular imaging technique capable of assessing device-vessel interactions at spatial resolution approaching 10 µm. We tested the hypothesis that adequately deployed Woven EndoBridge (WEB) devices as visualized by HF-OCT lead to higher aneurysm occlusion rates.

Methods: In a leporine model, elastase-induced aneurysms (n=24) were treated with the WEB device. HF-OCT and digital subtraction angiography (DSA) were performed following WEB deployment and repeated at 4, 8, and 12 weeks. Protrusion (0-present, 1-absent) and malapposition (0-malapposed, 1-neck apposition >50%) were binary coded. A device was considered 'adequately deployed' by HF-OCT and DSA if apposed and non-protruding. Aneurysm healing on DSA was reported using the 4-point WEB occlusion score: A or B grades were considered positive outcome. Neointimal coverage was quantified on HF-OCT images at 12 weeks and compared with scanning electron microscopy (SEM).

Results: Adequate deployment on HF-OCT correlated with positive outcome (P=0.007), but no statistically significant relationship was found between good outcome and adequate deployment on DSA (P=0.289). Absence of protrusion on HF-OCT correlated with a positive outcome (P=0.006); however, malapposition alone had no significant relationship (P=0.19). HF-OCT showed a strong correlation with SEM for the assessment of areas of neointimal tissue (R²=0.96; P<0.001). More neointimal coverage of 78%±32% was found on 'adequate deployment' cases versus 31%±24% for the 'inadequate deployment' cases (P=0.001).

Conclusion: HF-OCT visualizes features that can determine adequate device deployment to prognosticate early aneurysm occlusion following WEB implantation and can be used to longitudinally monitor aneurysm healing progression.
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http://dx.doi.org/10.1136/neurintsurg-2020-016447DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8205185PMC
July 2021

A neurovascular high-frequency optical coherence tomography system enables in situ cerebrovascular volumetric microscopy.

Nat Commun 2020 07 31;11(1):3851. Epub 2020 Jul 31.

New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA.

Intravascular imaging has emerged as a valuable tool for the treatment of coronary and peripheral artery disease; however, no solution is available for safe and reliable use in the tortuous vascular anatomy of the brain. Endovascular treatment of stroke is delivered under image guidance with insufficient resolution to adequately assess underlying arterial pathology and therapeutic devices. High-resolution imaging, enabling surgeons to visualize cerebral arteries' microstructure and micron-level features of neurovascular devices, would have a profound impact in the research, diagnosis, and treatment of cerebrovascular diseases. Here, we present a neurovascular high-frequency optical coherence tomography (HF-OCT) system, including an imaging console and an endoscopic probe designed to rapidly acquire volumetric microscopy data at a resolution approaching 10 microns in tortuous cerebrovascular anatomies. Using a combination of in vitro, ex vivo, and in vivo models, the feasibility of HF-OCT for cerebrovascular imaging was demonstrated.
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http://dx.doi.org/10.1038/s41467-020-17702-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7395105PMC
July 2020

Longitudinal Monitoring of Flow-Diverting Stent Tissue Coverage After Implant in a Bifurcation Model Using Neurovascular High-Frequency Optical Coherence Tomography.

Neurosurgery 2020 11;87(6):1311-1319

Department of Radiology, New England Center for Stroke Research, University of Massachusetts Medical School, Worcester, Massachusetts.

Background: Tissue growth over covered branches is a leading cause of delayed thrombotic complications after flow-diverter stenting (FDS). Due to insufficient resolution, no imaging modality is clinically available to monitor this phenomenon.

Objective: To evaluate high-frequency optical coherence tomography (HF-OCT), a novel intravascular imaging modality designed for the cerebrovascular anatomy with a resolution approaching 10 microns, to monitor tissue growth over FDS in an arterial bifurcation model.

Methods: FDS were deployed in a rabbit model (n = 6), covering the aortic bifurcation. The animals were divided in different groups, receiving dual antiplatelet therapy (DAPT) (n = 4), aspirin only (n = 1), and no treatment (n = 1). HF-OCT data were obtained in vivo at 3 different time points in each animal. For each cross-sectional image, metal and tissue coverage of the jailed ostium was quantified. Scanning electron microscopy images of harvested arteries were subsequently obtained.

Results: Good quality HF-OCT data sets were successfully acquired at implant and follow-up. A median value of 41 (range 21-55) cross-sectional images were analyzed per ostium for each time point. Between 0 and 30 d after implant, HF-OCT analysis showed a significantly higher ostium coverage when DAPT was not given. After 30 d, similar growth rates were found in the DAPT and in the aspirin group. At 60 d, a coverage of 90% was reached in all groups.

Conclusion: HF-OCT enables an accurate visualization of tissue growth over time on FDS struts. The use of FDS in bifurcation locations may induce a drastic reduction of the jailed-branch ostium area.
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http://dx.doi.org/10.1093/neuros/nyaa208DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7666887PMC
November 2020

Acute Thrombus Burden on Coated Flow Diverters Assessed by High Frequency Optical Coherence Tomography.

Cardiovasc Intervent Radiol 2020 Aug 8;43(8):1218-1223. Epub 2020 May 8.

New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, 55 Lake Ave N, SA-107R, Worcester, MA, 01655, USA.

Purpose: The implantation of flow diverters requires administration of dual anti-platelet therapy, posing the potential for complications. The p48MW HPC (phenox, Bochüm, Germany) hydrophilic-coated flow diverting stent is designed to be anti-thrombotic, thus opening the potential for single anti-platelet therapy. We deploy a novel intravascular high-resolution imaging technique, high-frequency optical coherence tomography (HF-OCT), to study in an animal model the acute thrombus formation on coated p48MW devices versus uncoated control devices.

Methods: Three pigs were implanted with 4 flow diverters each, two test hydrophilic-coated devices, and two control uncoated devices (p48MW). Each pig was treated with a different anti-platelet regime: no anti-platelet therapy, aspirin only, aspirin and clopidogrel. Twenty minutes after the flow diverter was implanted, an HF-OCT data set was acquired. Acute clot formed on the flow diverter at each covered side branch was measured from the HF-OCT slices. Factors considered to be important were the device type (pHPC versus bare metal), aspirin, clopidogrel, and vessel location. A linear model was constructed from the significant factors.

Results: Both coating (p < 0.001) and aspirin (p = 0.003) were significantly related to reduction in clot burden, leading to an approximate 100-fold and 50-fold reduction in clot, respectively.

Conclusions: This study shows the power of HF-OCT not only in the detection of clot but also the quantification of clot burden. In an animal model, the pHPC-coated p48MW significantly reduced acute thrombus formation over jailed side branches as compared to the bare metal p48MW that was nearly eliminated when combined with aspirin administration.
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http://dx.doi.org/10.1007/s00270-020-02482-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8209672PMC
August 2020

High frequency optical coherence tomography assessment of homogenous neck coverage by intrasaccular devices predicts successful aneurysm occlusion.

J Neurointerv Surg 2019 Nov 29;11(11):1150-1154. Epub 2019 Apr 29.

New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.

Background: High frequency optical coherence tomography (HF-OCT) is a novel intravascular imaging technology developed for use in the cerebral vasculature. We hypothesize that HF-OCT characterization of intrasaccular device neck coverage can prognosticate exclusion of the aneurysm from the circulation.

Methods: Bifurcation and sidewall aneurysms were made in six dogs. Seven aneurysms were treated with next generation intrasaccular devices (NGID) and four with traditional platinum coils. HF-OCT was performed to interrogate gaps in the neck coverage, coil herniation, or acute thrombus formation. Animals were re-imaged at 7, 30, 90, and 180 days following aneurysm embolization. An automated image processing method segmented the devices at the neck of the aneurysm and quantified neck coverage. The largest coverage gap was used to predict aneurysm occlusion at 180 days.

Results: No difference was found in occlusion rates between the coil and NGID groups (P=0.45). Successful segmentation of the NGID construct was achieved in all cases. A coverage gap >1 mm was found to predict failed aneurysm occlusion (P=0.047). This threshold was able to predict all cases of failed occlusion. The average number of devices needed to treat the aneurysm was lower in the NGID group (1.9 vs 6.75, P=0.009). HF-OCT showed strong agreement with scanning electron microscopy (bias 0.0024 mm (95% CI -0.0279, 0.0327)).

Conclusions: HF-OCT enables precise and accurate measurement of coverage gaps at the neck of aneurysms treated with intrasaccular devices in vivo. We provide in vivo evidence that uniform aneurysm neck coverage by intrasaccular devices is critical for aneurysm occlusion.
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http://dx.doi.org/10.1136/neurintsurg-2019-014843DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8204215PMC
November 2019

Intravascular Optical Coherence Tomography for Neurointerventional Surgery.

Stroke 2018 Nov 29:STROKEAHA118022315. Epub 2018 Nov 29.

From the New England Center for Stroke Research, Department of Radiology, University of Massachusetts Medical School, Worcester (M.J.G., G.J.U., M.M., A.S.P.).

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http://dx.doi.org/10.1161/STROKEAHA.118.022315DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6541539PMC
November 2018

Very late stent thrombosis and longitudinal stent deformation.

Acta Cardiol 2017 Apr 28;72(2):216-217. Epub 2017 Feb 28.

a ZNA Middelheim , Antwerp , Belgium.

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http://dx.doi.org/10.1080/00015385.2017.1291203DOI Listing
April 2017

Optical coherence tomography findings: insights from the "randomised multicentre trial investigating angiographic outcomes of hybrid sirolimus-eluting stents with biodegradable polymer compared with everolimus-eluting stents with durable polymer in chronic total occlusions" (PRISON IV) trial.

EuroIntervention 2017 Aug 4;13(5):e522-e530. Epub 2017 Aug 4.

Department of Cardiology, St. Antonius Hospital, Nieuwegein, the Netherlands.

Aims: The PRISON IV trial investigated the next-generation sirolimus-eluting stent (SES) with ultra-thin struts and biodegradable polymer against the second-generation everolimus-eluting stent (EES) with thin struts and durable polymer in patients with successfully recanalised chronic total occlusions (CTO). In this study, we examined the secondary optical coherence tomography endpoints.

Methods And Results: The main PRISON IV trial randomised 330 patients to either SES or EES. At nine months, 281 (85%) patients underwent repeat angiography. Of these, 60 consecutive patients received optical coherence tomography divided over both stent groups. The mean number of struts analysed was 750±337 and 633±358 in SES and EES patients, respectively (p=0.07). The minimal lumen area, minimal stent area, maximal neointima area and neointimal thickness were comparable between the groups (4.8±2.1 and 4.4±1.5 mm2; 5.3±1.8 and 5.3±1.4 mm2; 2.5±2.0 and 2.2±1.5 mm2; 0.7±1.7 and 0.4±0.2 mm). The percentage of uncovered struts was higher with EES (6.2±7.5% and 11.9±13.4%, p=0.04), whereas the percentage of malapposed struts and mean number of coronary evaginations were significantly higher with SES (2.9±4.0% and 1.2±2.4%, p=0.02; 18.5±17.7 and 5.3±3.1, p=0.004).

Conclusions: The optical coherence tomography findings of this substudy demonstrated improved strut coverage with ultra-thin strut SES with bioresorbable polymer compared to thin-strut EES with durable polymer in CTO. On the other hand, SES showed a higher rate of stent strut malappositon and coronary evaginations. The clinical relevance of these findings remains to be demonstrated.
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http://dx.doi.org/10.4244/EIJ-D-17-00261DOI Listing
August 2017

Automated characterisation of lipid core plaques in vivo by quantitative optical coherence tomography tissue type imaging.

EuroIntervention 2016 Dec;12(12):1490-1497

Thoraxcenter, Erasmus University Medical Center, Rotterdam, The Netherlands.

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.
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http://dx.doi.org/10.4244/EIJ-D-15-00320DOI Listing
December 2016

Anatomical and functional assessment of Tryton bifurcation stent before and after final kissing balloon dilatation: Evaluations by three-dimensional coronary angiography, optical coherence tomography imaging and fractional flow reserve.

Catheter Cardiovasc Interv 2017 Jul 27;90(1):E1-E10. Epub 2016 Aug 27.

Cardiovascular Research Center Aalst, OLV Clinic, Aalst, Belgium.

Objectives: To assess the anatomical and functional impact of final kissing balloon inflation (FKBI) after implantation of a dedicated bifurcation stent system.

Background: Current evidence suggests clinical benefit of FKBI in patients undergoing bifurcation dilatation using the Tryton side branch stent (Tryton-SBS). We hypothesized that FKBI improves anatomical reconstruction and functional results of bifurcation treated by Tryton-SBS.

Methods: An unselected group of patients with complex bifurcation coronary lesions undergoing percutaneous coronary intervention (PCI) with Tryton-SBS underwent paired anatomical assessment with two- and three-dimensional quantitative coronary analysis (2D- and 3D-QCA), and optical coherence tomography (OCT), including 3D reconstruction before and after FKBI. Functional assessment by fractional flow reserve (FFR) was performed in the main branch (MB) and side branch (SB) before and after FKBI.

Results: Paired pre- and post-FKBI data were obtained in 10 patients. By OCT imaging, FKBI increased both the SB ostial area (4.93 ± 2.81 vs. 7.43 ± 2.87 mm , P < 0.001) and the SB maximum diameter (3.12 ± 0.98 vs. 3.82 ± 1.10 mm, P = 0.003). These findings were associated with a significant increase in FFR in the SB (0.90 ± 0.05 vs. 0.94 ± 0.03; P = 0.011), with no significant change in the MB (0.91 ± 0.05 vs. 0.92 ± 0.04; P = 0.470).

Conclusions: In patients with complex bifurcation stenosis undergoing PCI with a dedicated bifurcation system, FKBI is associated with improved anatomical and functional results at the SB level, without compromising the result at the MB. © 2016 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/ccd.26777DOI Listing
July 2017

Targeted Near-Infrared Fluorescence Imaging of Atherosclerosis: Clinical and Intracoronary Evaluation of Indocyanine Green.

JACC Cardiovasc Imaging 2016 09 17;9(9):1087-1095. Epub 2016 Aug 17.

Cardiovascular Research Center, Division of Cardiology, Massachusetts General Hospital, Boston, Massachusetts; Cardiology Division, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts; Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts. Electronic address:

Objectives: This study sought to determine whether indocyanine green (ICG)-enhanced near-infrared fluorescence (NIRF) imaging can illuminate high-risk histologic plaque features of human carotid atherosclerosis, and in coronary atheroma of living swine, using intravascular NIRF-optical coherence tomography (OCT) imaging.

Background: New translatable imaging approaches are needed to identify high-risk biological signatures of atheroma. ICG is a U.S. Food and Drug Administration-approved NIRF imaging agent that experimentally targets plaque macrophages and lipid in areas of enhanced endothelial permeability. However, it is unknown whether ICG can target atheroma in patients.

Methods: Eight patients were enrolled in the BRIGHT-CEA (Indocyanine Green Fluorescence Uptake in Human Carotid Artery Plaque) trial. Five patients were injected intravenously with ICG 99 ± 25 min before clinically indicated carotid endarterectomy. Three saline-injected endarterectomy patients served as control subjects. Excised plaques underwent analysis by intravascular NIRF-OCT, reflectance imaging, microscopy, and histopathology. Next, following ICG intravenous injection, in vivo intracoronary NIRF-OCT and intravascular ultrasound imaged 3 atheroma-bearing coronary arteries of a diabetic, cholesterol-fed swine.

Results: ICG was well tolerated; no adverse clinical events occurred up to 30 days post-injection. Multimodal NIRF imaging including intravascular NIRF-OCT revealed that ICG accumulated in all endarterectomy specimens. Plaques from saline-injected control patients exhibited minimal NIRF signal. In the swine experiment, intracoronary NIRF-OCT identified ICG uptake in all intravascular ultrasound-identified plaques in vivo. On detailed microscopic evaluation, ICG localized to plaque areas exhibiting impaired endothelial integrity, including disrupted fibrous caps, and within areas of neovascularization. Within human plaque areas of endothelial abnormality, ICG was spatially related to localized zones of plaque macrophages and lipid, and, notably, intraplaque hemorrhage.

Conclusions: This study demonstrates that ICG targets human plaques exhibiting endothelial abnormalities and provides new insights into its targeting mechanisms in clinical and experimental atheroma. Intracoronary NIRF-OCT of ICG may offer a novel, clinically translatable approach to image pathobiological aspects of coronary atherosclerosis. (Indocyanine Green Fluorescence Uptake in Human Carotid Artery Plaque [BRIGHT-CEA]; NCT01873716).
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http://dx.doi.org/10.1016/j.jcmg.2016.01.034DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5136528PMC
September 2016

Automated segmentation and characterization of esophageal wall in vivo by tethered capsule optical coherence tomography endomicroscopy.

Biomed Opt Express 2016 Feb 8;7(2):409-19. Epub 2016 Jan 8.

Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Department of Pathology, Massachusetts General Hospital, Boston, MA, USA; Harvard-MIT Division of Health Sciences Technology, Cambridge, MA, USA.

Optical coherence tomography (OCT) is an optical diagnostic modality that can acquire cross-sectional images of the microscopic structure of the esophagus, including Barrett's esophagus (BE) and associated dysplasia. We developed a swallowable tethered capsule OCT endomicroscopy (TCE) device that acquires high-resolution images of entire gastrointestinal (GI) tract luminal organs. This device has a potential to become a screening method that identifies patients with an abnormal esophagus that should be further referred for upper endoscopy. Currently, the characterization of the OCT-TCE esophageal wall data set is performed manually, which is time-consuming and inefficient. Additionally, since the capsule optics optimally focus light approximately 500 µm outside the capsule wall and the best quality images are obtained when the tissue is in full contact with the capsule, it is crucial to provide feedback for the operator about tissue contact during the imaging procedure. In this study, we developed a fully automated algorithm for the segmentation of in vivo OCT-TCE data sets and characterization of the esophageal wall. The algorithm provides a two-dimensional representation of both the contact map from the data collected in human clinical studies as well as a tissue map depicting areas of BE with or without dysplasia. Results suggest that these techniques can potentially improve the current TCE data acquisition procedure and provide an efficient characterization of the diseased esophageal wall.
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http://dx.doi.org/10.1364/BOE.7.000409DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4771459PMC
February 2016

Clinical Characterization of Coronary Atherosclerosis With Dual-Modality OCT and Near-Infrared Autofluorescence Imaging.

JACC Cardiovasc Imaging 2016 11 9;9(11):1304-1314. Epub 2016 Mar 9.

Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts; Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Harvard-MIT Health Sciences and Technology, Boston, Massachusetts. Electronic address:

Objectives: The authors present the clinical imaging of human coronary arteries in vivo using a multimodality optical coherence tomography (OCT) and near-infrared autofluorescence (NIRAF) intravascular imaging system and catheter.

Background: Although intravascular OCT is capable of providing microstructural images of coronary atherosclerotic lesions, it is limited in its capability to ascertain the compositional/molecular features of plaque. A recent study in cadaver coronary plaque showed that endogenous NIRAF is elevated in necrotic core lesions. The combination of these 2 technologies in 1 device may therefore provide synergistic data to aid in the diagnosis of coronary pathology in vivo.

Methods: We developed a dual-modality intravascular imaging system and 2.6-F catheter that can simultaneously acquire OCT and NIRAF data from the same location on the artery wall. This technology was used to obtain volumetric OCT-NIRAF images from 12 patients with coronary artery disease undergoing percutaneous coronary intervention. Images were acquired during a brief, nonocclusive 3- to 4-ml/s contrast purge at a speed of 100 frames/s and a pullback rate of 20 or 40 mm/s. OCT-NIRAF data were analyzed to determine the distribution of the NIRAF signal with respect to OCT-delineated plaque morphological features.

Results: High-quality intracoronary OCT and NIRAF image data (>50-mm pullback length) were successfully acquired without complication in all patients (17 coronary arteries). The maximum NIRAF signal intensity of each plaque was compared with OCT-defined type, showing a statistically significant difference between plaque types (1-way analysis of variance, p < 0.0001). Interestingly, coronary arterial NIRAF intensity was elevated only focally in plaques with a high-risk morphological phenotype (p < 0.05), including OCT fibroatheroma, plaque rupture, and fibroatheroma associated with in-stent restenosis.

Conclusions: This OCT-NIRAF study demonstrates that dual-modality microstructural and fluorescence intracoronary imaging can be safely and effectively conducted in human patients. Our findings show that NIRAF is associated with a high-risk morphological plaque phenotype. The focal distribution of NIRAF in these lesions furthermore suggests that this endogenous imaging biomarker may provide complementary information to that obtained by structural imaging alone.
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http://dx.doi.org/10.1016/j.jcmg.2015.11.020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5010789PMC
November 2016

Optical coherence tomography-based assessment of bifurcation stenting using the Axxessª Biolimus A9ª-eluting stent system.

EuroIntervention 2016 Jan;11(9):1027

Department of Cardiovascular Medicine, University Hospitals Leuven, KU Leuven, Leuven, Belgium.

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http://dx.doi.org/10.4244/EIJV11I9A208DOI Listing
January 2016

Intravascular fibrin molecular imaging improves the detection of unhealed stents assessed by optical coherence tomography in vivo.

Eur Heart J 2017 02 18;38(6):447-455. Epub 2015 Dec 18.

Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA

Aims: Fibrin deposition and absent endothelium characterize unhealed stents that are at heightened risk of stent thrombosis. Optical coherence tomography (OCT) is increasingly used for assessing stent tissue coverage as a measure of healed stents, but cannot precisely identify whether overlying tissue represents physiological neointima. Here we assessed and compared fibrin deposition and persistence on bare metal stent (BMS) and drug-eluting stent (DES) using near-infrared fluorescence (NIRF) molecular imaging in vivo, in combination with simultaneous OCT stent coverage.

Methods And Results: Rabbits underwent implantation of one BMS and one DES without overlap in the infrarenal aorta (N = 20 3.5 × 12 mm). At Days 7 and/or 28, intravascular NIRF-OCT was performed following the injection of fibrin-targeted NIRF molecular imaging agent FTP11-CyAm7. Intravascular NIRF-OCT enabled high-resolution imaging of fibrin overlying stent struts in vivo, as validated by histopathology. Compared with BMS, DES showed greater fibrin deposition and fibrin persistence at Days 7 and 28 (P < 0.01 vs. BMS). Notably, for edge stent struts identified as covered by OCT on Day 7, 92.8 ± 9.5% of DES and 55.8 ± 23.6% of BMS struts were NIRF fibrin positive (P < 0.001). At Day 28, 18.6 ± 10.6% (DES) and 5.1 ± 8.7% (BMS) of OCT-covered struts remained fibrin positive (P < 0.001).

Conclusion: Intravascular NIRF fibrin molecular imaging improves the detection of unhealed stents, using clinically translatable technology that complements OCT. A sizeable percentage of struts deemed covered by OCT are actually covered by fibrin, particularly in DES, and therefore such stents might remain prothrombotic. These findings have implications for the specificity of standalone clinical OCT assessments of stent healing.
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http://dx.doi.org/10.1093/eurheartj/ehv677DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5837565PMC
February 2017

Intracoronary imaging of coronary atherosclerosis: validation for diagnosis, prognosis and treatment.

Eur Heart J 2016 Feb 11;37(6):524-35a-c. Epub 2015 Dec 11.

Department of Cardiology, Bern University Hospital, Bern 3010, Switzerland

While coronary atherosclerosis is a leading cause of mortality, evaluation of coronary lesions was previously limited to either indirect angiographic assessment of the lumen silhouette or post mortem investigations. Intracoronary (IC) imaging modalities have been developed that allow for visualization and characterization of coronary atheroma in living patients. Used alone or in combination, these modalities have enhanced our understanding of pathobiological mechanisms of atherosclerosis, identified factors responsible for disease progression, and documented the ability of various medications to reverse the processes of plaque growth and destabilization. These methodologies have established a link between in vivo plaque characteristics and subsequent coronary events, thereby improving individual risk stratification, paving the way for risk-tailored systemic therapies and raising the option for pre-emptive interventions. Moreover, IC imaging is increasingly used during coronary interventions to support therapeutic decision-making in angiographically inconclusive disease, guide and optimize procedural results in selected lesion and patient subsets, and unravel mechanisms underlying stent failure. This review aims to summarize current evidence regarding the role of IC imaging for diagnosis and risk stratification of coronary atherosclerosis, and to describe its clinical role for guiding percutaneous coronary interventions. Future perspectives for in-depth plaque characterization using novel techniques and multimodality imaging approaches are also discussed.
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http://dx.doi.org/10.1093/eurheartj/ehv642DOI Listing
February 2016

Multi-laboratory inter-institute reproducibility study of IVOCT and IVUS assessments using published consensus document definitions.

Eur Heart J Cardiovasc Imaging 2016 Jul 15;17(7):756-64. Epub 2015 Sep 15.

Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, BHX604A, Boston, MA 02114, USA Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA Department of Pathology, Harvard Medical School and Massachusetts General Hospital, Boston, MA, USA

Aims: The aim of this study was to investigate the reproducibility of intravascular optical coherence tomography (IVOCT) assessments, including a comparison to intravascular ultrasound (IVUS). Intra-observer and inter-observer variabilities of IVOCT have been previously described, whereas inter-institute reliability in multiple laboratories has never been systematically studied.

Methods And Results: In 2 independent laboratories with intravascular imaging expertise, 100 randomized matched data sets of IVOCT and IVUS images were analysed by 4 independent observers according to published consensus document definitions. Intra-observer, inter-observer, and inter-institute variabilities of IVOCT qualitative and quantitative measurements vs. IVUS measurements were assessed. Minor inter- and intra-observer variability of both imaging techniques was observed for detailed qualitative and geometric analysis, except for inter-observer mixed plaque identification on IVUS (κ = 0.70) and for inter-observer fibrous cap thickness measurement reproducibility on IVOCT (ICC = 0.48). The magnitude of inter-institute measurement differences for IVOCT was statistically significantly less than that for IVUS concerning lumen cross-sectional area (CSA), maximum and minimum lumen diameters, stent CSA, and maximum and minimum stent diameters (P < 0.001, P < 0.001, P < 0.001, P = 0.02, P < 0.001, and P = 0.01, respectively). Minor inter-institute measurement variabilities using both techniques were also found for plaque identification.

Conclusion: In the measurement of lumen CSA, maximum and minimum lumen diameters, stent CSA, and maximum and minimum stent diameters by analysts from two different laboratories, reproducibility of IVOCT was more consistent than that of IVUS.
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http://dx.doi.org/10.1093/ehjci/jev229DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4907381PMC
July 2016

Advances in Automated Assessment of Intracoronary Optical Coherence Tomography and Their Clinical Application.

Interv Cardiol Clin 2015 Jul 29;4(3):351-360. Epub 2015 May 29.

Department of Cardiovascular Sciences, Katholieke Universiteit Leuven, Herestraat 49, 3000 Leuven, Belgium; Department of Cardiovascular Diseases, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium; Department of Cardiovascular Medicine, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium. Electronic address:

Intravascular optical coherence tomography (OCT) is capable of acquiring 3-dimensional (3D) data of coronary arteries allowing for the assessment of plaques, stents, thrombus, side branches, and other relevant structures in a 3D fashion. Given that state-of-the-art OCT systems acquire images at a very high frame rate (up to 200 frames per second), typically a very large number of images per pullback (ie, 500 or more) need to be analyzed. The manual assessment of stents, plaques, and other structures is time-consuming, cumbersome, and inefficient and thus not suitable for on-line analysis during percutaneous coronary intervention procedures.
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http://dx.doi.org/10.1016/j.iccl.2015.02.004DOI Listing
July 2015

COmplex coronary Bifurcation lesions: RAndomized comparison of a strategy using a dedicated self-expanding biolimus-eluting stent versus a culotte strategy using everolimus-eluting stents: primary results of the COBRA trial.

EuroIntervention 2016 Apr;11(13):1457-67

Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium.

Aims: We aimed to compare healing responses with optical coherence tomography, and clinical and angiographic outcome after treatment of coronary bifurcation lesions with a dedicated stent versus a conventional culotte technique.

Methods And Results: Forty patients with true and complex coronary bifurcation lesions were randomly assigned to treatment with the Axxess™ bifurcation stent in the proximal main vessel (MV) and additional BioMatrix™ stents in the branches (Biosensors Europe SA, Morges, Switzerland), versus a culotte technique using XIENCE™ stents (Abbott Vascular, Santa Clara, CA, USA). The primary endpoint of percentage of uncovered struts at nine months was similar with the dedicated strategy vs. culotte in the proximal MV (median 17.8 [IQR 3.3-24.7] vs. 6.8 [2.0-20.5]; p=0.19), bifurcation core (9.5 [5.7-19.5] vs. 4.0 [0.7-17.6]; p=0.17), distal MV (2.6 [2.3-18] vs. 2.2 [0.5-6.0]; p=0.09) and side branch (5.7 [1.5-11.5] vs. 1.9 [0-5.8]; p=0.14). As compared with culotte, a strategy using Axxess resulted in a significantly larger lumen in the proximal MV both acutely (minimum lumen diameter 3.03±0.51 vs. 2.71±0.44 mm, p=0.04) and at follow-up (mean lumen area 10.0±2.1 vs. 7.1±1.8 mm2, p<0.001), and in a lower angiographic late lumen loss (p=0.05). Both strategies resulted in good clinical outcomes at one year, and no stent thromboses.

Conclusions: As compared with a culotte strategy with XIENCE stents, complex bifurcation stenting using a dedicated strategy combining Axxess and BioMatrix stents results in similar stent strut coverage at nine-month follow-up, and a significantly larger lumen and lower angiographic late lumen loss in the proximal MV.
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http://dx.doi.org/10.4244/EIJY15M05_02DOI Listing
April 2016

Ex vivo catheter-based imaging of coronary atherosclerosis using multimodality OCT and NIRAF excited at 633 nm.

Biomed Opt Express 2015 Apr 19;6(4):1363-75. Epub 2015 Mar 19.

Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, 02114 USA ; Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, 02114 USA ; Harvard-MIT Health Sciences and Technology, Cambridge, Massachusetts, USA.

While optical coherence tomography (OCT) has been shown to be capable of imaging coronary plaque microstructure, additional chemical/molecular information may be needed in order to determine which lesions are at risk of causing an acute coronary event. In this study, we used a recently developed imaging system and double-clad fiber (DCF) catheter capable of simultaneously acquiring both OCT and red excited near-infrared autofluorescence (NIRAF) images (excitation: 633 nm, emission: 680nm to 900nm). We found that NIRAF is elevated in lesions that contain necrotic core - a feature that is critical for vulnerable plaque diagnosis and that is not readily discriminated by OCT alone. We first utilized a DCF ball lens probe and a bench top setup to acquire en face NIRAF images of aortic plaques ex vivo (n = 20). In addition, we used the OCT-NIRAF system and fully assembled catheters to acquire multimodality images from human coronary arteries (n = 15) prosected from human cadaver hearts (n = 5). Comparison of these images with corresponding histology demonstrated that necrotic core plaques exhibited significantly higher NIRAF intensity than other plaque types. These results suggest that multimodality intracoronary OCT-NIRAF imaging technology may be used in the future to provide improved characterization of coronary artery disease in human patients.
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http://dx.doi.org/10.1364/BOE.6.001363DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4399675PMC
April 2015

STACCATO (Assessment of Stent sTrut Apposition and Coverage in Coronary ArTeries with Optical coherence tomography in patients with STEMI, NSTEMI and stable/unstable angina undergoing everolimus vs. biolimus A9-eluting stent implantation): a randomised controlled trial.

EuroIntervention 2016 Apr 8;11(14):e1619-26. Epub 2016 Apr 8.

Department of Cardiovascular Medicine, University Hospitals Leuven, Leuven, Belgium.

Aims: To compare tissue coverage in coronary lesions stented with durable fluoropolymer-coated everolimus-eluting stents (EES) vs. biodegradable polymer-coated biolimus A9-eluting stents (BES).

Methods And Results: Sixty-four patients (64 lesions) with de novo coronary artery lesions were randomised to percutaneous treatment with XIENCE EES (Abbott Vascular, Santa Clara, CA, USA) vs. BioMatrix BES (Biosensors, Morges, Switzerland). The primary endpoint was the percentage of uncovered struts, as assessed with OCT, at nine months. The average percentage of uncovered struts was significantly lower with EES (4.3±4.8% vs. 8.7±7.8% with BES, p=0.019). There was no difference in the average percentage of malapposed struts at baseline (6.8±6.9% vs. 6.9±7.0%, respectively, p=0.974) and at follow-up (0.1±0.3% vs. 0.6±1.3%, p=0.143). Neointimal thickness at nine months was 109±43 µm in EES vs. 64±18 µm in BES (p<0.001), and angiographic LLL was 0.15 mm in EES vs. 0.10 mm in BES (p=0.581). We did not observe differences in the incidence of MACE and ST.

Conclusions: A significantly higher percentage of uncovered struts was detected in the BioMatrix BES compared with the XIENCE EES at nine-month follow-up. Our findings do not support a preferential use of stents with biodegradable polymer-based biolimus elution to reduce the risk for ST.
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http://dx.doi.org/10.4244/EIJY14M11_11DOI Listing
April 2016

Dual modality intravascular optical coherence tomography (OCT) and near-infrared fluorescence (NIRF) imaging: a fully automated algorithm for the distance-calibration of NIRF signal intensity for quantitative molecular imaging.

Int J Cardiovasc Imaging 2015 Feb 24;31(2):259-68. Epub 2014 Oct 24.

Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, Boston, MA, USA,

Intravascular optical coherence tomography (IVOCT) is a well-established method for the high-resolution investigation of atherosclerosis in vivo. Intravascular near-infrared fluorescence (NIRF) imaging is a novel technique for the assessment of molecular processes associated with coronary artery disease. Integration of NIRF and IVOCT technology in a single catheter provides the capability to simultaneously obtain co-localized anatomical and molecular information from the artery wall. Since NIRF signal intensity attenuates as a function of imaging catheter distance to the vessel wall, the generation of quantitative NIRF data requires an accurate measurement of the vessel wall in IVOCT images. Given that dual modality, intravascular OCT-NIRF systems acquire data at a very high frame-rate (>100 frames/s), a high number of images per pullback need to be analyzed, making manual processing of OCT-NIRF data extremely time consuming. To overcome this limitation, we developed an algorithm for the automatic distance-correction of dual-modality OCT-NIRF images. We validated this method by comparing automatic to manual segmentation results in 180 in vivo images from six New Zealand White rabbit atherosclerotic after indocyanine-green injection. A high Dice similarity coefficient was found (0.97 ± 0.03) together with an average individual A-line error of 22 µm (i.e., approximately twice the axial resolution of IVOCT) and a processing time of 44 ms per image. In a similar manner, the algorithm was validated using 120 IVOCT clinical images from eight different in vivo pullbacks in human coronary arteries. The results suggest that the proposed algorithm enables fully automatic visualization of dual modality OCT-NIRF pullbacks, and provides an accurate and efficient calibration of NIRF data for quantification of the molecular agent in the atherosclerotic vessel wall.
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http://dx.doi.org/10.1007/s10554-014-0556-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4344893PMC
February 2015

Automated assessment and 3-dimensional visualization of the pattern of neointimal tissue maturity in vivo following drug-eluting stent implantation.

Int J Cardiovasc Imaging 2014 Oct 14;30(7):1235-6. Epub 2014 Jun 14.

Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium,

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http://dx.doi.org/10.1007/s10554-014-0465-1DOI Listing
October 2014

Effect of temperature and fixation on the optical properties of atherosclerotic tissue: a validation study of an ex-vivo whole heart cadaveric model.

Biomed Opt Express 2014 Apr 3;5(4):1038-49. Epub 2014 Mar 3.

Bristol Heart Institute, Bristol, UK.

Atherosclerotic plaque composition can be imaged using the optical attenuation coefficient derived from intravascular optical coherence tomography (OCT) data. The relation between optical properties and tissue type has been established on autopsy tissues. In this study, we validate an ex-vivo model for the effect of temperature and tissue fixation on optical parameters. We studied the optical attenuation of human coronary arteries at three temperatures, before and after formalin fixation. We developed an en-face longitudinal display of attenuation data of the OCT pullbacks. Using the unfixed, body-temperature condition image as a standard, and after extensive registration with other condition images, we quantify the differences in optical attenuation and the backscattered intensity. The results suggest that tissue fixation and temperature do not introduce systematic errors in studies of arterial optical properties.
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http://dx.doi.org/10.1364/BOE.5.001038DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3985992PMC
April 2014

Automated detection and quantification of clusters of malapposed and uncovered intracoronary stent struts assessed with optical coherence tomography.

Int J Cardiovasc Imaging 2014 Jun 26;30(5):839-48. Epub 2014 Mar 26.

Department of Cardiovascular Medicine, University Hospitals Leuven, Louvain, Belgium,

To date, accurate quantification and localization of malapposed and uncovered struts needs manual and time consuming analysis of large datasets. To develop an algorithm for automated detection and quantification of clusters of malapposed and uncovered struts in optical coherence tomography (OCT) pullbacks, including comprehensive information about their three-dimensional spatial distribution. 64 lesions in 64 patients treated with drug-eluting stent underwent assessment with OCT immediately after implantation and at 9-month follow-up (55 patients). An automated algorithm was used to detect and quantify stent strut malapposition at baseline and coverage at follow-up on an individual strut level. We subsequently applied an algorithm for the automated clustering of malapposed and uncovered struts and for the quantification of clusters' properties. In the 64 baseline examinations, a total of 24,013 struts were analyzed, of which 1,519 (6 %) were malapposed. Most malapposed struts (78 %) occurred in clusters and more than half of patients had malapposition clusters. The mean number of struts per cluster was 19.7 ± 11.8 with a mean malapposition distance of 213 ± 66 μm. In the 55 follow-up pullbacks, a total of 20,484 struts were analyzed, of which 1,320 (6 %) were uncovered. Again, most uncovered struts (85 %) occurred in clusters. The mean number of struts per cluster was 21.1 ± 14.7. We developed an automated algorithm for studying clustering of malapposed or uncovered struts. This algorithm might facilitate future investigations of the prognostic impact of clusters of malapposed or uncovered struts.
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http://dx.doi.org/10.1007/s10554-014-0406-zDOI Listing
June 2014

Healing course of acute vessel wall injury after drug-eluting stent implantation assessed by optical coherence tomography.

Eur Heart J Cardiovasc Imaging 2014 Jul 4;15(7):800-9. Epub 2014 Feb 4.

Department of Cardiovascular Diseases, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Leuven, Belgium Department of Cardiovascular Sciences, Katholieke Universiteit Leuven, Leuven, Belgium.

Background: Vessel wall injury after drug-eluting stent (DES) implantation can be characterized in detail by optical coherence tomography (OCT). Little is known about the healing course of these phenomena.

Methods And Results: In 62 lesions (62 patients), the incidence of acute vessel trauma was assessed in the stented region and the edge segments immediately after DES implantation. The healing course of these injuries was assessed at 9-month OCT follow-up using a software algorithm allowing for reliable spatial comparison of baseline and follow-up cross-sectional images. Tissue prolapse (TP) and tissue protrusions were detected in 81 and 35% of lesions, respectively. A total of 342 intra-stent dissection flaps (ISD) and 114 intra-stent dissection cavities (ISC) were visualized in 98 and 81% of lesions, respectively. Thirty-five lesions (56%) showed edge dissections (EDs). No residual TP or protrusion was observed at follow-up. Incomplete healing was seen in 8% of ISD and in 20% of ISC. For ED, a residual flap was observed in one-third of the initially dissected stent edges. Incomplete healing of acute vessel injury was associated with the presence of underlying atherosclerotic disease at baseline. Uncovered and malapposed stent struts were observed more often with incomplete healing of vessel injury at follow-up.

Conclusions: Acute vessel wall trauma is highly prevalent immediately after DES implantation. Most of these injuries are minor and resolve at mid-term follow-up. Incomplete healing of ISDs seems to be associated with other OCT findings suggesting delayed arterial healing.
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http://dx.doi.org/10.1093/ehjci/jeu003DOI Listing
July 2014
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