1. Articles from Hiram Bezerra

    1-16 of 16
    1. Deep neural networks for A-line-based plaque classification in coronary intravascular optical coherence tomography images

      Deep neural networks for A-line-based plaque classification in coronary intravascular optical coherence tomography images

      We develop neural-network-based methods for classifying plaque types in clinical intravascular optical coherence tomography (IVOCT) images of coronary arteries. A single IVOCT pullback can consist of >500 microscopic-resolution images, creating both a challenge for physician interpretation during an interventional procedure and an opportunity for automated analysis. In the proposed method, we classify each A-line, a datum element that better captures physics and pathophysiology than a voxel, as a fibrous layer followed by calcification (fibrocalcific), a fibrous layer followed by a lipidous deposit (fibrolipidic), or other. For A-line classification, the usefulness of a convolutional neural network (CNN) is compared with that ...

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    2. Mobilization of progenitor cells and assessment of vessel healing after second generation drug-eluting stenting by optical coherence tomography

      Mobilization of progenitor cells and assessment of vessel healing after second generation drug-eluting stenting by optical coherence tomography

      Background Bone marrow-derived progenitor cells likely contribute to both endothelial- and smooth muscle cell-dependent healing responses in stent-injured vessel sites. This study aimed to assess mobilization of progenitor cells and vessel healing after zotarolimus-eluting (ZES) and everolimus-eluting (EES) stents. Methods and results In 63 patients undergoing coronary stent implantation, we measured circulating CD34 + CD133 + CD45low cells and serum levels of biomarkers relevant to stem cell mobilization . In 31 patients of them, we assessed vessel healing within the stented segment using optical coherence tomography (OCT) imaging. The CD34 + CD133 + CD45low cells increased 68 ± 59% 7 days after bare metal stent (BMS ...

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    3. OCT guidance during stent implantation in primary Pci: A randomized multicenter study with nine months of optical coherence tomography follow-up

      OCT guidance during stent implantation in primary Pci: A randomized multicenter study with nine months of optical coherence tomography follow-up

      Aims To assess the possible merits of optical coherence tomography (OCT) guidance in primary percutaneous coronary intervention (pPCI). Methods and results 201 patients with ST-elevation myocardial infarction (STEMI) were enrolled in this study. Patients were randomized either to pPCI alone (angio-guided group, n = 96) or to pPCI with OCT guidance (OCT-guided group, n = 105) and also either to biolimus A9 or to everolimus-eluting stent implantation. All patients were scheduled for nine months of follow-up angiography and OCT study. OCT guidance led to post-pPCI optimization in 29% of cases (59% malapposition and 41% dissections). No complications were found related to the ...

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    4. Automated Volumetric Intravascular Plaque Classification Using Optical Coherence Tomography

      Automated Volumetric Intravascular Plaque Classification Using Optical Coherence Tomography

      An estimated 17.5 million people died from a cardiovascular disease in 2012, representing 31 percent of all global deaths. Most acute coronary events result from rupture of the protective fibrous cap overlying an atherosclerotic plaque. The task of early identification of plaque types that can potentially rupture is, therefore, of great importance. The state-of-the-art approach to imaging blood vessels is intravascular optical coherence tomography (IVOCT). However, currently, this is an offline approach where the images are first collected and then manually analyzed an image at a time to identify regions at risk of thrombosis. This process is extremely laborious ...

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    5. Angiographic and Intracoronary Manifestations of Coronary Fibromuscular Dysplasia

      Angiographic and Intracoronary Manifestations of Coronary Fibromuscular Dysplasia

      Background— We previously described a strong association between fibromuscular dysplasia (FMD) and spontaneous coronary artery dissection. Angiographic manifestations of coronary FMD aside from dissection were considered rare. However, we observed several coronary FMD angiographic abnormalities with corresponding optical coherence tomography abnormalities. Methods and Results— Baseline demographics and imaging of patients with suspected coronary FMD at Vancouver General Hospital were reviewed. Presence of multifocal (string-of-beads) extracoronary FMD was confirmed by 2 specialists. In these patients, coronary angiographic findings (excluding dissected segments) were reviewed and classified by 2 experienced angiographers for irregular stenosis, that is, stenosis with irregular borders in a focal ...

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      Mentions: Hiram G. Bezerra
    6. Coronary optical coherence tomography: A practical overview of current clinical applications

      Coronary optical coherence tomography: A practical overview of current clinical applications

      Coronary optical coherence tomography has emerged as the most powerful in-vivo imaging modality to evaluate vessel structure in detail. It is a useful research tool that provides insights into the pathogenesis of coronary artery disease. This technology has an important clinical role that is still being developed. We review the evidence on the wide spectrum of potential clinical applications for coronary optical coherence tomography, which encompass the successive stages in coronary artery disease management: accurate lesion characterization and quantification of stenosis, guidance for the decision to perform percutaneous coronary intervention and subsequent planning, and evaluation of immediate and long-term results ...

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    7. Comparative analysis method of permanent metallic stents (XIENCE) and bioresorbable poly-L-lactic (PLLA) scaffolds (Absorb) on optical coherence tomography at baseline and follow-up

      Comparative analysis method of permanent metallic stents (XIENCE) and bioresorbable poly-L-lactic (PLLA) scaffolds (Absorb) on optical coherence tomography at baseline and follow-up

      Aims: Fully bioresorbable Absorb poly-L-lactic-acid (PLLA) scaffolds (Abbott Vascular, Santa Clara, CA, USA) are a novel approach for the treatment of coronary narrowing. Due to the translucency of the material (PLLA), the optical coherence tomography (OCT) measurement methods used in the ABSORB trials were unique but not applicable for permanent metallic stents. When the Absorb scaffold and metallic stents are compared in the context of randomised trials, it is challenging to compare the two devices using the conventional methods. The primary purpose of this report is to explain the biases in conventional methodologies applied for metallic stents and for PLLA ...

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    8. Optical coherence tomography imaging during percutaneous coronary intervention impacts physician decision-making: ILUMIEN I Study

      Optical coherence tomography imaging during percutaneous coronary intervention impacts physician decision-making: ILUMIEN I Study

      Aims ILUMIEN I is the largest prospective, non-randomized, observational study of percutaneous coronary intervention (PCI) procedural practice in patients undergoing intra-procedural pre- and post-PCI fractional flow reserve (FFR) and optical coherence tomography (OCT). We report on the impact of OCT on physician decision-making and the association with post-PCI FFR values and early clinical events. Methods and results Optical coherence tomography and documentary FFR were performed pre- and post-PCI in 418 patients (with 467 stenoses) with stable or unstable angina or NSTEMI. Based on pre-PCI OCT, the procedure was altered in 55% of patients (57% of all stenoses) by selecting different ...

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    9. Mechanisms of Atherothrombosis and Vascular Response to Primary Percutaneous Coronary Intervention in Women Versus Men With Acute Myocardial Infarction : Results of the OCTAVIA (Optical Coherence Tomography Assessment of Gender Diversity in Primary Angiop

      Mechanisms of Atherothrombosis and Vascular Response to Primary Percutaneous Coronary Intervention in Women Versus Men With Acute Myocardial Infarction : Results of the OCTAVIA (Optical Coherence Tomography Assessment of Gender Diversity in Primary Angiop

      Objectives This study sought to assess in vivo sex differences in the pathophysiology of ST-segment elevation myocardial infarction (STEMI) and vascular response to primary percutaneous coronary intervention (PCI). Background There is no consensus on whether differences in the pathophysiology of STEMI and response to primary PCI between women and men reflect biological factors as opposed to differences in age. Methods In this prospective, multicenter study, 140 age-matched men and women with STEMI undergoing primary PCI with everolimus-eluting stent were investigated with intravascular optical coherence tomography, histopathology-immunohistochemistry of thrombus aspirates, and serum biomarkers. Primary endpoints were the percentages of culprit plaque ...

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    10. Segmentation and quantification for intravascular optical coherence tomography images

      Segmentation and quantification for intravascular optical coherence tomography images

      A system and related methods for automatic or semi-automatic segmentation and quantification of blood vessel structure and physiology, including segmentation and quantification of lumen, guide wire, vessel wall, calcified plaques, fibrous caps, macrophages, metallic and bioresorbable stents are described, and including visualization of results. Calcified plaque segmentation can be used to estimate the distribution of superficial calcification and inform strategies stenting. Volumetric segmentation and quantification of fibrous caps can provide more comprehensive information of the mechanisms behind plaque rupture. Quantification of macrophages can aid diagnosis and prediction of unstable plaque and associated acute coronary events. Automated detection and quantification of ...

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    11. Very long-term follow-up of strut apposition and tissue coverage with Biolimus A9 stents analyzed by optical coherence tomography

      Very long-term follow-up of strut apposition and tissue coverage with Biolimus A9 stents analyzed by optical coherence tomography

      First generation drug-eluting stents (DES) are associated with reduced in-stent restenosis but significant increased risk of very late stent thrombosis (VLST). The absence of polymer in DES systems may reduce the occurrence of VLST. Optic coherence tomography (OCT) has been used for stent analysis as a surrogate safety endpoint. This study aimed to assess the long-term follow up of strut apposition and tissue coverage of BioMatrix™ DES by OCT. 20 patients undergoing BioMatrix™ DES (n = 15) or S-Stent™ BMS (n = 5) implantation were followed for at least 5 years and evaluated by quantitative coronary angiography, intravascular ultrasound, and OCT. The ...

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    12. Three-Dimensional Fourier-Domain Optical Coherence Tomography Imaging: Advantages and Future Development

      Three-Dimensional Fourier-Domain Optical Coherence Tomography Imaging: Advantages and Future Development

      Traditionally, intravascular imaging methods display the coronary anatomy in two dimensions, through a series of consecutive cross-sectional tomographic images. The physician is then required to mentally reassemble these images in order to visualize the vascular anatomy and all its complex interactions. The ability to depict the vascular structure with its actual spatial appearance, in three dimensions, is a powerful way to provide an easy, objective, and comprehensive overview of its complex and dynamic anatomy. However, three-dimensional (3D) application of intravascular imaging has been plagued by lack of enough resolution, frequent presence of imaging and motion artifacts and need for extensive ...

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    13. Impact of Drug Release Kinetics on Vascular Response to Different Zotarolimus-Eluting Stents Implanted in Patients With Long Coronary Stenoses: The LongOCT Study (Optical Coherence Tomography in Long Lesions)

      Impact of Drug Release Kinetics on Vascular Response to Different Zotarolimus-Eluting Stents Implanted in Patients With Long Coronary Stenoses: The LongOCT Study (Optical Coherence Tomography in Long Lesions)
      Objectives We assessed the in vivo vascular response to a new generation of zotarolimus-eluting stents (ZES) with prolonged drug release (Resolute ZES-SR, Medtronic Vascular, Santa Rosa, California) compared with ZES with faster kinetics (Endeavor ZES-FR, Medtronic Vascular) by optical coherence tomography. Background Local drug release kinetics has been implicated with antirestenosis efficacy of drug-eluting stents. However, the impact of different release kinetics on vascular response of diseased human coronary arteries remains to be investigated. Methods The study population consisted of 43 patients with long lesions in native coronary vessels treated with multiple overlapping ZES. Twenty-one patients treated with ZES-SR were ...
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    14. Optical Coherence Tomography and Fibrous Cap Characterization

      Optical Coherence Tomography and Fibrous Cap Characterization
      The pathophysiology of acute coronary syndromes has long been associated with atherosclerotic plaque rupture. Inflammation, thinning, and disruption of the fibrous cap have been implicated with the final processes leading to plaque rupture, but confirmation of these mechanisms of coronary thrombosis in humans has been hampered by the lack of imaging methods with sufficient resolution to resolve fibrous cap characterization and thickness in vivo. Intravascular optical coherence tomography (OCT) provides images with micron-level axial and lateral resolution, enabling detailed visualization of micro-structural changes of the arterial wall. The present article provides an overview of the potential role of OCT in ...
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    15. Strut Coverage and Vessel Wall Response to Zotarolimus-Eluting and Bare-Metal Stents Implanted in Patients With ST-Segment Elevation Myocardial Infarction: The Octami (Optical Coherence Tomography in Acute Myocardial Infarction) Study

      Strut Coverage and Vessel Wall Response to Zotarolimus-Eluting and Bare-Metal Stents Implanted in Patients With ST-Segment Elevation Myocardial Infarction: The Octami (Optical Coherence Tomography in Acute Myocardial Infarction) Study
      Objectives Using optical coherence tomography, we assessed the proportion of uncovered struts at 6-month follow-up in zotarolimus-eluting stents (ZES), specifically Endeavor (Medtronic CardioVascular, Santa Rosa, California) stents, and identical bare-metal stents (BMS) implanted in patients with ST-segment elevation myocardial infarction (STEMI). Background Sirolimus- and paclitaxel-eluting stents implanted in STEMI have been associated with delayed healing and incomplete strut coverage. ZES are associated with a more complete and uniform strut coverage in stable patients, but whether this holds true also after STEMI is unknown. Methods Forty-four patients with STEMI who underwent primary PCI were randomized to ZES or BMS (3:1 ...
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    16. Reproducibility of quantitative optical coherence tomography for stent analysis

      Aims: To assess the inter- and intra- observer reproducibility for strut count, strut apposition and strut tissue coverage measurements with optical coherence tomography (OCT).Methods and results: Ten drug-eluting stents (244 frames, 1712 struts) imaged with OCT nine months after implantation were analysed by two independent analysts. One of the analysts repeated the analysis of five stents (120 frames, 795 struts) one week later. Offline analysis was performed with the proprietary LightLab Imaging software. The number of struts was counted and lumen and stent area contours were traced. Tissue coverage thickness was measured at 360 degrees of vessel circumference and ...
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    1-16 of 16
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  2. Topics in the News

    1. (16 articles) Hiram G. Bezerra
    2. (13 articles) Case Western Reserve University
    3. (12 articles) Marco A. Costa
    4. (6 articles) National Institutes of Health
    5. (4 articles) David L. Wilson
    6. (4 articles) Giulio Guagliumi
    7. (4 articles) Andrew M. Rollins
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    11. (3 articles) Zhao Wang
    12. (2 articles) UC Irvine
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    14. (2 articles) Zhongping Chen
    15. (2 articles) Yifan Jian
    16. (2 articles) Heidelberg Engineering
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    Strut Coverage and Vessel Wall Response to Zotarolimus-Eluting and Bare-Metal Stents Implanted in Patients With ST-Segment Elevation Myocardial Infarction: The Octami (Optical Coherence Tomography in Acute Myocardial Infarction) Study Optical Coherence Tomography and Fibrous Cap Characterization Impact of Drug Release Kinetics on Vascular Response to Different Zotarolimus-Eluting Stents Implanted in Patients With Long Coronary Stenoses: The LongOCT Study (Optical Coherence Tomography in Long Lesions) Three-Dimensional Fourier-Domain Optical Coherence Tomography Imaging: Advantages and Future Development Very long-term follow-up of strut apposition and tissue coverage with Biolimus A9 stents analyzed by optical coherence tomography Segmentation and quantification for intravascular optical coherence tomography images Mechanisms of Atherothrombosis and Vascular Response to Primary Percutaneous Coronary Intervention in Women Versus Men With Acute Myocardial Infarction : Results of the OCTAVIA (Optical Coherence Tomography Assessment of Gender Diversity in Primary Angiop Optical coherence tomography imaging during percutaneous coronary intervention impacts physician decision-making: ILUMIEN I Study Comparative analysis method of permanent metallic stents (XIENCE) and bioresorbable poly-L-lactic (PLLA) scaffolds (Absorb) on optical coherence tomography at baseline and follow-up The Effect of Anti-Tubercular Drugs on Retinal Nerve Fiber Layer Thickness Using Optical Coherence Tomography A Cross-sectional Optical Coherence Tomography Study in Patients on Taxane-based Therapy and A Case Report with the Literature Review Association of systemic inflammatory biomarkers with morphological characteristics of the coronary atherosclerotic plaque by intravascular optical coherence tomography.