1. Articles from Kunihiro Shimamura

    1-24 of 24
    1. Intracoronary pressure increase due to contrast injection for optical coherence tomography imaging

      Intracoronary pressure increase due to contrast injection for optical coherence tomography imaging

      Background Optical coherence tomography (OCT) requires intracoronary injection of contrast media to remove blood from the field of view during image acquisition. Contrast injection may cause a temporal increase in intracoronary pressure. The aim of this study was to compare the intracoronary pressure during contrast injection between OCT and coronary angiography . Methods We measured intracoronary pressure by using a pressure guidewire during contrast injection for OCT and angiography in 30 coronary arteries (mean fractional flow reserve = 0.90 ± 0.03). Contrast media was injected into coronary artery through the guiding catheter by using a mechanical injector pump. Results Intracoronary pressure ...

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    2. 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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    3. 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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    4. 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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    5. 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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    6. The OPTIS Integrated System: real-time, co-registration of angiography and optical coherence tomography

      The OPTIS Integrated System: real-time, co-registration of angiography and optical coherence tomography

      The efficacy of an IVUS-guided stent implantation strategy to improve acute results and clinical outcome has been described previously. OCT is another technique which allows high-resolution intracoronary imaging. However, the use of invasive imaging modalities to guide PCI has, as yet, played a limited role in current clinical practice. This may be partly explained by the expertise required for interpretation and clinical decision making. We present a novel technology which enables real-time co-registration of OCT images with angiography. This will simplify matching cross-sectional images to their geographic position on the angiogram, thereby facilitating imaging-guided PCI.

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    7. Optical Coherence Tomography for Online Guidance of Complex Coronary Interventions

      Optical Coherence Tomography for Online Guidance of Complex Coronary Interventions

      Decision making on lesion preparation and stent/scaffold optimization are cornerstones of patient outcome. Intravascular imaging recently emerged as a critical modality to achieve better results of stent/scaffold implantation and superior clinical outcomes compared with coronary angiography alone. Optical coherence tomography (OCT), a light-based intravascular imaging modality with high frame rate in acquisition and very high speed pullback, can interrogate the target vessel in a couple of seconds, and immediately display a pristine longitudinal lumen contour with automatic detection of lesion severity, site and lumen/stent areas. Further, OCT provides pivotal information on sites of calcium, with accurate measurements ...

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    8. Impact of Culprit Plaque and Atherothrombotic Components on Incomplete Stent Apposition in Patients With ST-Elevation Myocardial Infarction Treated With Everolimus-Eluting Stents – An OCTAVIA Substudy –

      Impact of Culprit Plaque and Atherothrombotic Components on Incomplete Stent Apposition in Patients With ST-Elevation Myocardial Infarction Treated With Everolimus-Eluting Stents – An OCTAVIA Substudy –

      Background: The role of culprit plaque and related atherothrombotic components on incomplete stent apposition (ISA) occurrence after primary percutaneous coronary intervention (p-PCI) is unknown. Methods and Results: ST-segment elevation myocardial infarction (STEMI) patients undergoing p-PCI with an everolimus-eluting stent were prospectively investigated with optical coherence tomography (OCT) of the infarct-related artery before, after stenting and at 9 months. OCT data, aspirated thrombus and serum inflammatory biomarkers were analyzed. 114 patients with 114 lesions were evaluated. Acute ISA occurred in 82 lesions (71.9%), preferentially in larger vessels with a median area of 0.2 mm 2 . The presence of thrombus ...

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    9. Optimal threshold of postintervention minimum stent area to predict in-stent restenosis in small coronary arteries: An optical coherence tomography analysis

      Optimal threshold of postintervention minimum stent area to predict in-stent restenosis in small coronary arteries: An optical coherence tomography analysis

      Objectives The aim of this study was to determine the best threshold of postintervention minimum stent area (MSA) assessed by optical coherence tomography (OCT) to predict long-term in-stent restenosis (ISR) for 2.5 mm-diameter everolimus-eluting stents (EES). Background Percutaneous coronary intervention (PCI) for small coronary arteries remains challenging. Stent underexpansion is a strong predictor of late ISR. Methods We performed a retrospective analysis of 69 lesions in 69 patients undergoing PCI with 2.5 mm-diameter stents using OCT for the assessment of postintervention MSA and subsequent 9-month angiographic follow-up. Results The rates of angiographic ISR and target lesion revascularization were ...

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    10. Comparison of vascular response between everolimus-eluting stent and bare metal stent implantation in ST-segment elevation myocardial infarction assessed by optical coherence tomography

      Comparison of vascular response between everolimus-eluting stent and bare metal stent implantation in ST-segment elevation myocardial infarction assessed by optical coherence tomography

      Aims The long-term safety of second-generation everolimus-eluting stents (EESs) in ST-segment elevation myocardial infarction (STEMI) remains unclear. The aim of this study was to evaluate the late vascular response after stent implantation in STEMI between EES and bare-metal stent (BMS) by using optical coherence tomography (OCT). Methods and results A prospective OCT examination was performed in 102 patients at 10 months after stent implantation for treatment of STEMI. A total of 1253 frames with 12 772 struts in 61 EESs and 776 frames with 8594 struts in 41 BMSs were analysed. There were no significant differences in the percentage of ...

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    11. Effect of Atorvastatin Therapy on Fibrous Cap Thickness in Coronary Atherosclerotic Plaque as Assessed by Optical Coherence Tomography The EASY-FIT Study

      Effect of Atorvastatin Therapy on Fibrous Cap Thickness in Coronary Atherosclerotic Plaque as Assessed by Optical Coherence Tomography The EASY-FIT Study

      Background The detailed mechanism of plaque stabilization by statin therapy is not fully understood. Objectives The aim of this study was to assess the effect of lipid-lowering therapy with 20 mg/day of atorvastatin versus 5 mg/day of atorvastatin on fibrous cap thickness in coronary atherosclerotic plaques by using optical coherence tomography (OCT). Methods Seventy patients with unstable angina pectoris and untreated dyslipidemia were randomized to either 20 mg/day or 5 mg/day of atorvastatin therapy. OCT was performed to assess intermediate nonculprit lesions at baseline and 12-month follow-up. Results Serum low-density lipoprotein cholesterol level was significantly lower ...

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    12. Outcomes of everolimus-eluting stent incomplete stent apposition: a serial optical coherence tomography analysis

      Outcomes of everolimus-eluting stent incomplete stent apposition: a serial optical coherence tomography analysis

      Aim The aim of the present study was to evaluate the natural course of acute incomplete stent apposition (ISA) after second-generation everolimus-eluting stent (EES) when compared with first-generation sirolimus-eluting stent (SES) by using optical coherence tomography (OCT). Methods and results From the OCT substudy of the RESET trial, we identified 77 patients (EES = 38 and SES = 39) who successfully underwent serial OCT examination at post-stenting and 8–12-month follow-up. The presence of ISA was assessed in the OCT images, and ISA distance was measured from the centre of the strut blooming to the adjacent lumen border. Incomplete stent apposition was ...

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    13. Impact of Eicosapentaenoic Acid Treatment on the Fibrous Cap Thickness in Patients with Coronary Atherosclerotic Plaque: An Optical Coherence Tomography Study

      Impact of Eicosapentaenoic Acid Treatment on the Fibrous Cap Thickness in Patients with Coronary Atherosclerotic Plaque: An Optical Coherence Tomography Study

      Aim : Previous clinical trials have demonstrated the effectiveness of eicosapentaenoic acid (EPA) in preventing cardiovascular events. The aim of the present study was to investigate the effects of EPA treatment on the accumulation of coronary atherosclerotic plaque using optical coherence tomography (OCT). Methods : A total of 46 acute coronary syndrome (ACS) patients without dyslipidemia were divided into two groups: those who received 1,800 mg/day of EPA ( n =15) or the control group ( n =31). Serial OCT examinations were performed at baseline and after eight months of follow-up. The target for the OCT analysis was non-culprit plaque with a ...

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    14. Difference of Ruptured Plaque Morphology between Asymptomatic Coronary Artery Disease and Non-ST Elevation Acute Coronary Syndrome Patients: an Optical Coherence Tomography Study

      Difference of Ruptured Plaque Morphology between Asymptomatic Coronary Artery Disease and Non-ST Elevation Acute Coronary Syndrome Patients: an Optical Coherence Tomography Study

      Background Autopsy studies have reported that rupture of a thin-cap fibroatheroma and subsequent thrombus formation is the major mechanism leading to acute coronary syndrome (ACS). However, it is not clear why only some plaque ruptures lead to ACS. Optical coherence tomography (OCT) is a high-resolution imaging modality which is capable of investigating detailed coronary plaque morphology in vivo. The objective of this study was to determine whether ruptured plaque morphology assessed by OCT differs between asymptomatic coronary artery disease (CAD) and non-ST elevation acute coronary syndrome (NSTEACS). Methods We examined ruptured plaque morphology using OCT in 80 patients, 33 with ...

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    15. Association between P-selectin Glycoprotein Ligand-1 and Pathogenesis in Acute Coronary Syndrome Assessed by Optical Coherence Tomography

      Association between P-selectin Glycoprotein Ligand-1 and Pathogenesis in Acute Coronary Syndrome Assessed by Optical Coherence Tomography

      Objective Although monocytes appear to be actively involved in the onset of acute coronary syndrome (ACS), they are heterogenous in human peripheral blood. How up-regulation of monocyte subsets leads to coronary plaque rupture followed by thrombus formation remains unclear. Recent studies have shown that P-selectin glycoprotein ligand-1 (PSGL-1) is involved in monocyte activation in patients with thrombus formation. We therefore investigated the relationship between the expression of PSGL-1 on monocyte subsets and thrombus formation using frequency-domain optical coherence tomography (FD-OCT) in patients with ACS. Methods We enrolled a total of 100 individuals in this study: patients with acute myocardial infarction ...

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    16. Comparison of longitudinal geometric measurement in human coronary arteries between frequency-domain optical coherence tomography and intravascular ultrasound

      Comparison of longitudinal geometric measurement in human coronary arteries between frequency-domain optical coherence tomography and intravascular ultrasound

      Previous studies have demonstrated the higher accuracy of frequency-domain optical coherence tomography (FD-OCT) for quantitative measurements in comparison with intravascular ultrasound (IVUS). However, those analyses were based on the cross-sectional images. The aim of this study was to assess the accuracy of FD-OCT for longitudinal geometric measurements of coronary arteries in comparison with IVUS. Between October 2011 and March 2012, we performed prospective FD-OCT and IVUS examinations in consecutive 77 patients who underwent percutaneous coronary intervention with single stent. Regression analysis and Bland-Altman analysis revealed an excellent correlation between the FD-OCT-measured stent lengths and IVUS-measured stent lengths (r = 0.986 ...

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    17. Inter-Scan Reproducibility of Geometric Coronary Artery Measurements Using Frequency-Domain Optical Coherence Tomography

      Inter-Scan Reproducibility of Geometric Coronary Artery Measurements Using Frequency-Domain Optical Coherence Tomography

      Frequency-domain optical coherence tomography (FD-OCT) is a novel technology which provides high-resolution cross-sectional images of coronary arteries. The aim of this study was to evaluate the inter-scan reproducibility of geometric FD-OCT measurements in the clinical setting. We examined 20 coronary lesions using FD-OCT. Following the FD-OCT image acquisition (1 st pullback), and after the disengagement and re-engagement of the guiding catheter, an additional acquisition (2 nd pullback) was performed using a new FD-OCT catheter. There was excellent correlation for minimum lumen area ( r = 0.99, P < 0.001), lesion length ( r = 0.99, P < 0.001) and lumen volume ( r ...

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    18. Difference in neointimal appearance between early and late restenosis after sirolimus-eluting stent implantation assessed by optical coherence tomography

      Difference in neointimal appearance between early and late restenosis after sirolimus-eluting stent implantation assessed by optical coherence tomography

      Objectives: Late in-stent restenosis (ISR) is an important clinical issue in the drug-eluting stent era. Autopsy studies have reported different underlying mechanisms between early ISR and late ISR. The aim of the present study was to compare the neointimal tissue appearance between early ISR (<1 year) and late ISR (>1 year) after sirolimus-eluting stent (SES) implantation using optical coherence tomography (OCT). Materials and methods: We examined the neointimal tissue appearance in 48 ISR lesions after SES implantation [30 early ISR lesions (8±1 months after stenting) and 18 late ISR lesions (34±14 months after stenting)] by OCT. ISR was ...

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    19. Optical Coherence Tomography-Derived Anatomical Criteria for Functionally Significant Coronary Stenosis Assessed by Fractional Flow Reserve

      Optical Coherence Tomography-Derived Anatomical Criteria for Functionally Significant Coronary Stenosis Assessed by Fractional Flow Reserve

      Background: For the identification of functionally significant coronary artery disease, there have not been any dedicated optical coherence tomography (OCT) studies reported previously, although OCT can clearly detect coronary vessel lumina at higher resolution than intravascular ultrasound (IVUS). Methods and Results: OCT and fractional flow reserve (FFR) measurements were performed in 62 intermediate coronary lesions in 59 patients. FFR was calculated as the ratio of distal coronary pressure divided by proximal coronary pressure during maximal hyperemia. FFR <0.75 was used as the threshold for diagnosing functionally significant stenosis. Minimal lumen area (MLA), minimal lumen diameter (MLD) and percent lumen ...

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    20. Effect of strut thickness on neointimal atherosclerotic change over an extended follow-up period (≥4 years) after bare-metal stent implantation: Intracoronary optical coherence tomography examination

      Effect of strut thickness on neointimal atherosclerotic change over an extended follow-up period (≥4 years) after bare-metal stent implantation: Intracoronary optical coherence tomography examination

      Background Neointima inside the bare-metal stents (BMSs) can transform into atherosclerotic tissue during an extended follow-up because of a persistent inflammatory reaction to the metal. We sought to investigate whether strut thickness may impact on the atherosclerotic change in neointima 4 years or more after BMS implantation using optical coherence tomography. Methods Forty-six stented lesions of 41 patients with BMS ≥4 years after implantation who underwent optical coherence tomography were enrolled in the study. The strut was defined as thin when less than 100 μm and thick when ≥100 μm. According to these criteria, stents were divided into 2 groups ...

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    21. Optical Coherence Tomography Analysis of Clinical and Subclinical

      Optical Coherence Tomography Analysis of Clinical and Subclinical

      Background: Coronary plaque ruptures occur not only in acute coronary syndrome (ACS) patients but also in non-ACS patients. There is a great interest in the reason why some plaque ruptures lead to ACS but others do not. We used optical coherence tomography (OCT) to identify anatomic features that lead to the development of culprit lesions causing ACS after plaque rupture.Methods: We assessed 102 plaque ruptures by using OCT and compared lesion morphologies betweensymptomatic plaque rupture in unstable angina pectoris (UAP; n=67) and silent plaque rupture in stable anginapectoris (SAP; n=35).Results: In the cross-sectional view, rupture was ...

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    Optical Coherence Tomography Analysis of Clinical and Subclinical Effect of strut thickness on neointimal atherosclerotic change over an extended follow-up period (≥4 years) after bare-metal stent implantation: Intracoronary optical coherence tomography examination Optical Coherence Tomography-Derived Anatomical Criteria for Functionally Significant Coronary Stenosis Assessed by Fractional Flow Reserve Difference in neointimal appearance between early and late restenosis after sirolimus-eluting stent implantation assessed by optical coherence tomography Inter-Scan Reproducibility of Geometric Coronary Artery Measurements Using Frequency-Domain Optical Coherence Tomography Comparison of longitudinal geometric measurement in human coronary arteries between frequency-domain optical coherence tomography and intravascular ultrasound Association between P-selectin Glycoprotein Ligand-1 and Pathogenesis in Acute Coronary Syndrome Assessed by Optical Coherence Tomography Difference of Ruptured Plaque Morphology between Asymptomatic Coronary Artery Disease and Non-ST Elevation Acute Coronary Syndrome Patients: an Optical Coherence Tomography Study Impact of Eicosapentaenoic Acid Treatment on the Fibrous Cap Thickness in Patients with Coronary Atherosclerotic Plaque: An Optical Coherence Tomography Study Effect of Atorvastatin Therapy on Fibrous Cap Thickness in Coronary Atherosclerotic Plaque as Assessed by Optical Coherence Tomography The EASY-FIT Study Optical Coherence Tomography Angiography in Myopic Patients Quantification of retinal microvasculature and neurodegeneration changes in branch retinal vein occlusion after resolution of cystoid macular edema on optical coherence tomography angiography