1. Articles from Takashi Akasaka

    1-24 of 110 1 2 3 4 5 »
    1. Imaging assessment and accuracy in coronary artery autopsy: comparison of frequency-domain optical coherence tomography with intravascular ultrasound and histology

      Imaging assessment and accuracy in coronary artery autopsy: comparison of frequency-domain optical coherence tomography with intravascular ultrasound and histology

      ptical coherence tomography (OCT) is a coronary artery imaging technique with high resolution. Second-generation frequency-domain OCT (FD-OCT) technology allows safer and faster clinical application compared with first-generation time-domain OCT (TD-OCT). Only limited validation studies compare FD-OCT with other modes of analysis: histology, which is the current gold standard, and intravascular ultrasound (IVUS). This study therefore aims to demonstrate the accuracy of FD-OCT images compared with IVUS and histology. FD-OCT and IVUS images were acquired from 203 segments from 31 coronary arteries obtained at autopsy from 20 cadavers. Of these, 30 randomly-selected pairs were used to create three classifications of plaque ...

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    2. Optical coherence tomography in varying aetiologies of renal artery stenosis: a case series

      Optical coherence tomography in varying aetiologies of renal artery stenosis: a case series

      Background Renal artery stenosis (RAS) is a common cause of secondary hypertension. The most common aetiology is atherosclerosis; however, other causes like fibromuscular dysplasia (FMD) and Takayasu arteritis (TA) are also frequently encountered. The lesion characteristics and its response to percutaneous intervention depend upon the aetiology of RAS. Optical coherence tomography (OCT) is an excellent imaging modality to analyse coronary lesions during percutaneous coronary interventions. The data regarding the utility of OCT in renal artery imaging is limited, consisting of a few case reports. Case summary We hereby report four cases of RAS, each of different aetiology (atherosclerotic, FMD, post-transplant ...

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      Mentions: Takashi Akasaka
    3. Clinical use of intracoronary imaging. Part 2: acute coronary syndromes, ambiguous coronary angiography findings, and guiding interventional decision-making: an expert consensus document of the European Association of Percutaneous Cardiovascular Intervent

      Clinical use of intracoronary imaging. Part 2: acute coronary syndromes, ambiguous coronary angiography findings, and guiding interventional decision-making: an expert consensus document of the European Association of Percutaneous Cardiovascular Intervent

      This consensus document is the second of two reports summarizing the views of an expert panel organized by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on the clinical use of intracoronary imaging including intravascular ultrasound (IVUS), optical coherence tomography (OCT), and near infrared spectroscopy (NIRS)-IVUS. Beyond guidance of stent selection and optimization of deployment, invasive imaging facilitates angiographic interpretation and may guide treatment in acute coronary syndrome. Intravascular imaging can provide additional important diagnostic information when confronted with angiographically ambiguous lesions and allows assessment of plaque morphology enabling identification of vulnerability characteristics. This second document focuses on useful ...

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    4. Stabilization of High Risk Coronary Plaque on Optical Coherence Tomography and Near-Infrared Spectroscopy by Intensive Lipid-Lowering Therapy With Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) Inhibitor

      Stabilization of High Risk Coronary Plaque on Optical Coherence Tomography and Near-Infrared Spectroscopy by Intensive Lipid-Lowering Therapy With Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) Inhibitor

      A 70-year-old woman with hypertension and dyslipidemia underwent drug-eluting stent implantation in the mid-left anterior descending artery (LAD) due to acute coronary syndrome (ACS). Optical coherence tomography (OCT) during the index procedure showed lipid-rich plaque in non-culprit lesions of the proximal LAD and mid-right coronary artery (Figure B,E). Near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) showed plaque with high lipid burden in both sites (Figure C,F). Intensive lipid-lowering therapy with combined strong statin and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor was started after the index procedure. Scheduled 10-month follow-up OCT and NIRS-IVUS showed increase in minimum fibrous cap thickness ...

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    5. Role of Optical Coherence Tomography in the Diagnosis of Spontaneous Coronary Artery Dissection

      Role of Optical Coherence Tomography in the Diagnosis of Spontaneous Coronary Artery Dissection

      Spontaneous coronary artery dissection (SCAD) is an infrequent and often missed diagnosis among patients with acute coronary syndrome (ACS), especially young healthy females. Unfortunately, SCAD can result in significant morbidity, such as ischemia and infarction. Currently, there has been a surge in the diagnosis of SCAD due to the widespread use of new intracoronary imaging modalities, especially optical coherence tomography (OCT).However, no specific guidelines exist concerning appropriate treatment for SCAD. Moreover, the role of intracoronary imaging with OCT has yet to be fully established. The aim of our review is to provide a comprehensive contemporary update of SCAD; the ...

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    6. New Volumetric Analysis Method for Stent Expansion and its Correlation With Final Fractional Flow Reserve and Clinical Outcome An ILUMIEN I Substudy

      New Volumetric Analysis Method for Stent Expansion and its Correlation With Final Fractional Flow Reserve and Clinical Outcome An ILUMIEN I Substudy

      Download figure Open in new tab Download powerpoint Abstract Objectives This study sought to compare conventional methodology (CM) with a newly described optical coherence tomography (OCT)-derived volumetric stent expansion analysis in terms of fractional flow reserve (FFR)-derived physiology and device-oriented composite endpoints (DoCE). Background The analysis of coronary stent expansion with intracoronary imaging has used CM that relies on the analysis of selected single cross-sections for several decades. The introduction of OCT with its ability to perform semiautomated volumetric analysis opens opportunities to redefine optimal stent expansion. Methods A total of 291 lesions treated with post-stent OCT and ...

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    7. Late clinical outcome of suboptimal stent implantation defined by intracoronary optical coherence tomography

      Late clinical outcome of suboptimal stent implantation defined by intracoronary optical coherence tomography

      Optical coherence tomography (OCT) is an intravascular imaging technique that provides high-resolution (10-20 μm) images. During percutaneous coronary intervention (PCI), OCT offers useful information to guide treatment strategies and assess optimal stent implantation (Figure 1) . However, OCT remains markedly underused in the real world. For further integration of OCT into clinical practice, it is necessary to accumulate evidence showing that OCT has a beneficial impact on the outcomes of PCI. In 2012 and 2015, Prati et al 1,2 reported the clinical benefits of OCT guidance in PCI using data

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    8. In vivo optical coherence tomography imaging and histopathology of healed coronary plaques

      In vivo optical coherence tomography imaging and histopathology of healed coronary plaques

      Background and aims The aims of this study were to assess agreement between optical coherence tomography (OCT) and histopathology for healed coronary plaques (HCPs) in human coronary arteries ex vivo , and to evaluate the prevalence and characteristics of HCPs in vivo . Methods Ex vivo OCT images were co-registered with histopathology in 144 cross-sections with ≥50% stenosis. Of these, 30 randomly selected pairs were employed to define morphological features of OCT for HCPs (OCT-derived HCPs); the remaining 114 pairs were used to evaluate the accuracy of OCT in detecting histologically-defined HCPs. In a clinical study, 60 target lesions from 60 patients ...

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    9. The role of optical coherence tomography in the setting of acute myocardial infarction

      The role of optical coherence tomography in the setting of acute myocardial infarction

      In recent years, intravascular imaging-guided percutaneous coronary intervention (PCI) has been increasing in patients with acute myocardial infarction (AMI). However, the role of optical coherence tomography (OCT) has not been established in the setting of AMI despite OCT providing superior resolution (10 μm axial resolution) and facilitating assessment of baseline lesion characteristics and post-intervention evaluation of the acute result of stent implantation, including visualization of procedural dissections, malapposition, tissue prolapse, and thrombus. We provide an overview of the potential benefits of OCT-guidance in various situations of AMI

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    10. Comparison between Optical COherence tomography guidance and Angiography guidance in percutaneous coronary intervention (COCOA): Study protocol for a randomized controlled trial

      Comparison between Optical COherence tomography guidance and Angiography guidance in percutaneous coronary intervention (COCOA): Study protocol for a randomized controlled trial

      Background Optical coherence tomography (OCT) is increasingly used as an adjunct to coronary angiography for guiding percutaneous coronary intervention (PCI). The current consensus on PCI is that the large final stent area offers the best chance of a good late clinical outcome. Since OCT provides more accurate information about the coronary artery and implanted stents, OCT-guided stent implantation is expected to achieve greater stent expansion than angiography guidance alone. Therefore, we designed the COCOA (Comparison between Optical COherence tomography guidance and Angiography guidance in percutaneous coronary intervention) study to evaluate whether OCT-guided stent implantation would result in a minimum stent ...

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    11. Effect of Early Pitavastatin Therapy on Coronary Fibrous-Cap Thickness Assessed by Optical Coherence Tomography in Patients With Acute Coronary Syndrome : The ESCORT Study

      Effect of Early Pitavastatin Therapy on Coronary Fibrous-Cap Thickness Assessed by Optical Coherence Tomography in Patients With Acute Coronary Syndrome : The ESCORT Study

      Objectives The aim of the present study was to assess the effect of early statin therapy on fibrous-cap thickness in coronary plaques of patients with acute coronary syndrome (ACS) by using optical coherence tomography. Background Statins can contribute to the stabilization of coronary plaques. Methods This is a prospective, randomized, active-controlled, single-center study. Patients with ACS and untreated dyslipidemia were enrolled and randomly allocated (ratio 1:1) to either the early statin group (received pitavastatin 4 mg/day from baseline) or the late statin group (received pitavastatin 4 mg/day from 3 weeks after the baseline). Optical coherence tomography was ...

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    12. Optical frequency domain imaging vs. intravascular ultrasound in percutaneous coronary intervention (OPINION trial): one-year angiographic and clinical results

      Optical frequency domain imaging vs. intravascular ultrasound in percutaneous coronary intervention (OPINION trial): one-year angiographic and clinical results

      Aims Optical frequency domain imaging (OFDI) is a recently developed, light-based, high-resolution intravascular imaging technique. Intravascular ultrasound (IVUS) is a widely used, conventional imaging technique for guiding percutaneous coronary intervention (PCI). We aimed to demonstrate the non-inferiority of OFDI-guided PCI compared with IVUS-guided PCI in terms of clinical outcomes. Methods and results We did a prospective, multicentre, randomized (ratio 1:1), active-controlled, non-inferiority study to compare head-to-head OFDI vs. IVUS in patients undergoing PCI with a second generation drug-eluting stent. The primary endpoint was target vessel failure defined as a composite of cardiac death, target-vessel related myocardial infarction, and ischaemia-driven ...

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    13. Suboptimal agreement between optical coherence tomography and near-infrared spectroscopy for identification of lipid-laden plaque

      Suboptimal agreement between optical coherence tomography and near-infrared spectroscopy for identification of lipid-laden plaque

      Recently developed intracoronary imaging techniques allow real-time, in vivo identification of lipid in atherosclerotic plaques. Optical coherence tomography (OCT), a light-based imaging technique with high axial resolution (10-20 μm), identifies lipid-laden plaques as signal-poor regions with diffuse borders. A validation study performed versus histopathology confirmed the high sensitivity (90% to 94%) and specificity (90% to 92%) of OCT to identify lipid-laden plaques 1 . Near-infrared spectroscopy (NIRS) detects lipid-laden plaque by analysing light absorption that varies depending on the coronary tissue components and the wavelength of the incident near-infrared light. NIRS displays the probability of the presence of lipid-laden plaque on ...

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    14. Morphological and pharmacological determinants of peri-procedural myocardial infarction following elective stent implantation: Optical coherence tomography sub-analysis of the PRASFIT-Elective study

      Morphological and pharmacological determinants of peri-procedural myocardial infarction following elective stent implantation: Optical coherence tomography sub-analysis of the PRASFIT-Elective study

      Background Previous studies have suggested that peri-procedural myocardial infarction (PMI) following percutaneous coronary intervention (PCI) is associated with adverse short- and long-term outcomes, and several morphological predictors of PMI have been studied. However, the determinants of PMI under novel anti-platelet therapy are not fully elucidated. Methods and results PRASFIT-Elective is a multicenter, parallel-group study of PCI patients in non-acute settings receiving either prasugrel or clopidogrel in addition to aspirin. Among 742 study patients, 94 (116 lesions) underwent optical coherence tomography (OCT) to evaluate the area of intra-stent tissue (IST, which comprises tissue protrusion and thrombus) after stenting in addition to ...

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    15. Two-year vascular responses to drug-eluting stents with biodegradable polymer versus durable polymer: An optical coherence tomography sub-study of the NEXT

      Two-year vascular responses to drug-eluting stents with biodegradable polymer versus durable polymer: An optical coherence tomography sub-study of the NEXT

      Background This study aimed to compare very late vascular response after stent implantation between everolimus-eluting stent (EES) with a thin, non-adhesive, durable, biocompatible fluorinated polymer and biolimus-eluting stent (BES) with a biodegradable polymer by optical coherence tomography (OCT). Methods and results In the NOBORI-BES Versus XIENCE V/PROMUS-EES Trial (NEXT), a formal OCT substudy investigated 48 patients (27 EES-treated lesions in 23 patients and 28 BES-treated lesions in 25 patients) with 2-year (18–30 months) follow-up imaging at 18 centers. The percentage of uncovered strut by neointima was significantly lower in EES compared with BES (2.1 ± 4.7% vs ...

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    16. Thrombus and Plaque Erosion Characterized by Optical Coherence Tomography in Patients With Vasospastic Angin

      Thrombus and Plaque Erosion Characterized by Optical Coherence Tomography in Patients With Vasospastic Angin

      Introduction and objectives Vasospastic angina (VSA) can result in endothelial damage and thrombus formation. The aim of this study was to evaluate the incidence of thrombus and plaque characteristics at coronary spasm segments compared with nonspasm segments by using optical coherence tomography (OCT) in patients with suspected VSA. Methods One hundred and eighty-three patients with suspected VSA were enrolled in this study. The ergonovine provocation test was performed in all patients for the diagnosis of VSA except in patients with spontaneous spasm. All target lesions were analyzed by OCT. Plaque erosion was defined as the presence of attached thrombus overlying ...

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    17. Optical coherence tomography compared with intravascular ultrasound and with angiography to guide coronary stent implantation (ILUMIEN III: OPTIMIZE PCI): a randomised controlled trial

      Optical coherence tomography compared with intravascular ultrasound and with angiography to guide coronary stent implantation (ILUMIEN III: OPTIMIZE PCI): a randomised controlled trial

      Background Percutaneous coronary intervention (PCI) is most commonly guided by angiography alone. Intravascular ultrasound (IVUS) guidance has been shown to reduce major adverse cardiovascular events (MACE) after PCI, principally by resulting in a larger postprocedure lumen than with angiographic guidance. Optical coherence tomography (OCT) provides higher resolution imaging than does IVUS, although findings from some studies suggest that it might lead to smaller luminal diameters after stent implantation. We sought to establish whether or not a novel OCT-based stent sizing strategy would result in a minimum stent area similar to or better than that achieved with IVUS guidance and better ...

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    18. Optical Coherence Tomography Predictors for Edge Restenosis After Everolimus-Eluting Stent Implantation

      Optical Coherence Tomography Predictors for Edge Restenosis After Everolimus-Eluting Stent Implantation

      Background— Stent edge restenosis (SER) remains a potential limitation of drug-eluting stents. The aim of this study was to determine optical coherence tomography (OCT) predictors for angiographic late SER after everolimus-eluting stent implantation. Methods and Results— We retrospectively analyzed 319 patients who underwent OCT immediately after everolimus-eluting stent implantation and scheduled 9- to 12-month follow-up angiography. The binary angiographic SER rate was 10% (32/319) in the patients, 8.4% (32/382) in lesions, and 4.4% (33/744) in stent edge segments. In the stent edge segments at post stenting, OCT-derived lipidic plaque (61% versus 20%; P <0.001 ...

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    19. Angiographic, optical coherence tomography and histology findings from combination of a drug-coated balloon with an everolimus-eluting stent in a porcine mode

      Angiographic, optical coherence tomography and histology findings from combination of a drug-coated balloon with an everolimus-eluting stent in a porcine mode

      Background We designed a porcine model to compare the angiographic, optical coherence tomography (OCT) and histological findings of implanting an everolimus-eluting stent (EES) in the same segment of the coronary artery pre-treated with a drug-coating balloon (DCB; paccocath as carrier) with EES alone and DCB plus a bare metal stent (BMS). Methods Seven female swine averaging 46.0±2.4 kg were treated by random assignment as follows: DCB followed by EES; DCB followed by BMS; and EES alone. Quantitative coronary angiography (QCA) and OCT were carried out post-implantation and repeated after 28±1 days. Results All arteries remained patent ...

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    20. Assessment of Vascular Response after Stent Implantation by Intracoronary Optical Coherence Tomograph

      Assessment of Vascular Response after Stent Implantation by Intracoronary Optical Coherence Tomograph

      Optical coherence tomography (OCT) is a high resolution (10-20 μm) imaging modality that provides microscopic visualization of the coronary artery including vascular response after stent implantation. Compared to conventional intravascular ultrasound, OCT can more clearly identify findings immediately after stent implantation, such as tissue protrusion, stent edge dissection, and incomplete stent strut apposition. Furthermore, OCT allows clinicians to accurately assess the late acquired stent malapposition and strut coverage which could be a surrogate marker for stent thrombosis after drug-eluting stent (DES) implantation. OCT can evaluate not only the extent and amount of neointima but also the tissue characteristics of neointimal ...

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    21. Reduction of in-stent thrombus immediately after percutaneous coronary intervention by pretreatment with prasugrel compared with clopidogrel: An optical coherence tomography study

      Reduction of in-stent thrombus immediately after percutaneous coronary intervention by pretreatment with prasugrel compared with clopidogrel: An optical coherence tomography study

      Background Prasugrel is a new-generation thienopyridine antiplatelet agent that provides more consistent and prompt platelet inhibition than clopidogrel. The aim of this study was to compare in-stent thrombus inhibition effect of pretreatment with prasugrel and clopidogrel by using optical coherence tomography (OCT) immediately after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Methods We performed OCT immediately after PCI in 108 ACS patients pretreated with either prasugrel ( n = 51) or clopidogrel ( n = 57). OCT detected thrombus/plaque protrusion in all stented segments. Results Although stent volume (190.4 ± 119.1 mm 3 vs. 189.4 ± 95.8 mm 3 ...

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    22. The use of optical coherence tomography in acute coronary syndrome

      The use of optical coherence tomography in acute coronary syndrome

      Optical coherence tomography (OCT) is an intracoronary imaging modality which utilizes near-infrared light to provide high-resolution cross-sectional in-vivo images of the coronary artery. OCT imaging technique enables detailed evaluation of plaque morphology in patients with acute coronary syndrome and helps to understand the underlying mechanisms including plaque rupture, plaque erosion, and calcified nodule. It is useful to optimize percutaneous coronary intervention, and evaluate vascular response to coronary intervention and pharmacological therapy. Advances in intracoronary OCT and further research on clinical applications have the potential to contribute to a better prognosis in acute coronary syndrome.

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