Background: Optical flow ratio (OFR) is a recently developed method for functional assessment of coronary artery disease based on computational fluid dynamics of vascular anatomical data from intravascular optical coherence tomography (OCT). The purpose of this study was to investigate the relationship between OFR and fractional flow reserve (FFR) in stent-treated arteries immediately after percutaneous coronary intervention (PCI). Methods and Results: The OFR and FFR were measured in 103 coronary arteries immediately after successful PCI with a stent. An increase in the OFR and FFR values within the stent was defined as in-stent ∆OFR and ∆FFR, respectively. The values of ...

Background: The relationship between the characteristics of tissue protrusion detected by using optical coherence tomography (OCT) and the findings of coronary angioscopy (CAS) immediately after stent implantation were evaluated. Methods and Results: A total of 186 patients (192 stents) underwent OCT before and after stenting and were observed by using CAS immediately after stenting and at the chronic phase. Patients were assigned to irregular protrusion, smooth protrusion, and disrupted fibrous tissue protrusion groups according to OCT findings. Serum high-sensitivity C-reactive protein (hs-CRP) levels were measured before and after stent implantation. The grade of yellow color (YC) and neointimal coverage (NC ...

Very late stent thrombosis (VLST) is a potentially life-threatening complication in coronary angioplasty patients. The patient was a 95-year-old man who had been implanted with a durable polymer everolimus-eluting stent (DP-EES, 3.5 × 23 mm) at the restenosis site in the proximal part of the left descending artery using only plain balloon angioplasty for acute coronary syndrome (ACS) 27 months earlier. Final intravascular ultrasound (IVUS) evaluation had shown no stent malapposition and adequate stent expansion. However, he presented to our hospital due to vomiting and fatigue 89 months after the implantation. An electrocardiogram showed ST-elevation in V2-6 leads, we therefore ...

Purpose: To investigate fatigue damage over time, monolithic posterior computer-aided-designed/computer-aided-manufactured (CAD/CAM) crowns were artificially aged in a mouth-motion-simulator, and damage was monitored with optical coherence tomography (OCT). Methods: Forty-eight crowns were milled of six different CAD/CAM-materials (n=8), including 3Y-TZP (Lava Plus,‘3Y’), 4Y-PSZ (Pritidentamultidisc,‘4Y’), 5Y-PSZ (Prettauanterior,‘5Y’), zirconia-reinforced lithium silicate (CeltraDuo,‘ZLS’), hybrid ceramic (Vita Enamic,‘VE’),and resin composite (BrilliantCrios,‘COM’), and were adhesively luted on CAD/CAM-milled human molars. Specimens were artificially aged in a mouth-motion-simulator (50-500N, 2Hz, 37°C) for a period of 1 million cycles. Before loading and every 250,000 ...

Summary In-stent restenosis (ISR) still exists after drug-eluting stent (DES) implantation, even up to one year. The incidence and risk factors for neoatherosclerosis in patients with early ISR have not yet been elucidated. Here, we used optical coherence tomography (OCT) to evaluate the incidence and predictors of neoatherosclerosis in patients with early ISRs. OCT was performed on ISR lesions in 185 patients in order to detect neoatherosclerosis. The median follow-up was 180 days, and neoatherosclerosis was detected in 37% of early ISR lesions. According to the presence of neoatherosclerosis, patients with ISR were divided into two groups: neoatherosclerosis (group A ...

Background: The excessive volume of contrast needed is a significant limitation of optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI). Low-molecular-weight dextran (LMWD) has been used for OCT image acquisition instead of contrast media. This study compared the effects of OCT-guided PCI using LMWD on renal function and clinical outcomes to those of intravascular ultrasound (IVUS)-guided PCI. Methods and Results: In all, 1,183 consecutive patients who underwent intracoronary imaging-guided PCI were enrolled in this single-center, retrospective, observational study. After propensity score matching, 133 pairs of patients were assigned to undergo either OCT-guided PCI using LMWD or IVUS-guided ...

Background: Acute myocardial infarction (AMI) is caused by coronary plaque rupture (PR), plaque erosion (PE), or calcified nodule (CN). We used optical coherence tomography (OCT) to compare stent expansion immediately after primary percutaneous coronary intervention (PCI) in patients with AMI caused by PR, PE, or CN. Methods and Results: In all, 288 AMI patients were assessed by OCT before and immediately after PCI, performed with OCT guidance according to OPINION criteria for stent sizing and optimization. The frequency of OCT-identified PR (OCT-PR), OCT-PE, and OCT-CN was 172 (60%), 82 (28%), and 34 (12%), respectively. Minimum stent area was smallest in ...

No abstract provided.

Background: We previously reported that ST-segment elevation myocardial infarction （STEMI） patients with large residual thrombus burden after thrombectomy before stent implantation had more severe microvascular dysfunction, and greater myocardial damage compared with those with small residual thrombus. However, clinical significance of residual thrombus after stent implantation in STEMI patients is unclear. Aims: This study aimed to evaluate the incidence of thrombus by optical coherence tomography （OCT） after stent implantation, and to investigate its clinical impact in STEMI patients. Methods and Results: A total of 180 STEMI patients within 12 hours after onset of symptoms were studied. Patients were divided into ...

Long-term patency of saphenous vein graft (SVG) remains challenging.1 A 75-year-old man on hemodialysis had undergone coronary artery bypass grafting (CABG) 11 years earlier. At the current presentation he underwent percutaneous coronary intervention (PCI) for SVG failure to the diagonal branch (Figure A). Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) showed convex calcifications at the severe proximal anastomotic stenosis (Figure B,C) and tandem stenotic sites (Figure D,E). In addition, coronary angioscopy (CAS) indicated punctate red thrombus on a protruding mass (Figure F). These findings were suggestive of calcified nodules (CN). A 3.5×48-mm stent was ...

Abstract Background: The risks of ventricular fibrillation (Vfib) associated with frequency-domain optical coherence tomography (OCT)/optical frequency domain imaging (OFDI) remain undetermined. Methods and Results: We retrospectively studied the occurrence of Vfib during OCT/OFDI for unselected indications. The frequency of Vfib and patient and procedural characteristics were investigated. A total of 4,467 OCT/OFDI pullback examinations were performed in 1,754 patients (median of 2.0 [2.0–3.0] pullbacks for 1.0 [1.0–1.3] vessels). OCT/OFDI was performed during PCI in 899 patients (51.3%). The contrast injection volume per pullback was 14 ...

Although metallic stents improved the safety and efficacy of percutaneous coronary intervention (PCI), even the latest generation of drug-eluting stents (DES) is still limited by several factors. The limitations of DES are mainly related to the permanent metallic caging in vessel, chronic inflammatory response to the polymer and adverse effects of antiproliferative drug on endothelial tissue, leading to impaired physiological vasomotor response and late stent-related adverse events such as stent thrombosis and neoatherosclerosis. Bioresorbable vascular scaffold (Absorb BVS; Abbott Vascular) was designed to overcome these drawbacks of DES by disappearing from the vessel wall. Absorb BVS, however, was withdrawn from ...

The microscopic tissue structure and organization influence the polarization of light. Intravascular polarimetry leverages this compelling intrinsic contrast mechanism by using polarization-sensitive optical frequency domain imaging to measure the polarization properties of the coronary arterial wall. Tissues rich in collagen and smooth muscle cells appear birefringent, while the presence of lipid causes depolarization, offering quantitative metrics related to the presence of important components of coronary atherosclerosis. Here, we review the basic principles, the interpretation of polarization signatures, and first clinical investigations of intravascular polarimetry and discuss how this extension of contemporary intravascular imaging may advance our knowledge and improve clinical ...

Background: Attenuation-compensated (AC) technique was recently introduced to improve the plaque characterization of optical coherence tomography (OCT). Histological validation demonstrated promising results but the efficacy and reproducibility of this technique for assessing in-vivo tissue composition remains unclear. Methods and Results: OCT images portraying native (n=200) and stented (n=200) segments and 31 histological cross-sections were analyzed. AC-OCT appeared superior to conventional (C)-OCT in detecting the external elastic lamina (EEM) borders (76% vs. 65.5%); AC-OCT enabled larger EEM arc detection compared with C-OCT (174.2±58.7° vs. 137.5±57.9°; P<0.001). There was poor ...

I ntravascular optical coherence tomography (OCT) is a light-based imaging modality that enables detailed visualization of the intraluminal structures in coronary arteries. High-resolution (10–20μm) cross-sectional images are generated by measuring the echo time delay and intensity of light that is reflected or backscattered from the internal structures in tissues.1,2 OCT is clinically useful during percutaneous coronary intervention (PCI) to assess lesion severity, optimize stent implantation, and characterize atherosclerotic plaques, including the identification of thin-cap fibroatheroma (TCFA) and lipid-rich plaques, which are reportedly responsible for periprocedural complications. OCT can also be used to assess the mechanism for ...

Clinical researches show that the morbidity of coronary artery disease (CAD) is gradually increasing in many countries every year, and it causes hundreds of thousands of people all over the world dying for each year. As the optical coherence tomography with high resolution and better contrast applied to the lesion tissue investigation of human vessel, many more micro-structures of the vessel could be easily and clearly visible to doctors, which help to improve the CAD treatment effect. Manual qualitative analysis and classification of vessel lesion tissue are time-consuming to doctors because a single-time intravascular optical coherence (IVOCT) data set of ...

Background: Healed plaques are identified as a layered pattern with optical coherence tomography (OCT) imaging, but the exact relationship between healed plaques and the development of significant coronary stenosis in stable angina pectoris (SAP) is not fully understood. Methods and Results: A retrospective clinincal study investigated the OCT characteristics of culprit lesions of SAP patients (n=205), and a prospective study examined the histopathological characteristics of layered plaque in directional coronary atherectomy (DCA) samples (42 samples from 18 SAP patients). In the retrospective study, layered plaque was observed in 36.6% of the SAP culprit lesions. Compared with patients with ...

An 80-year-old man with severe kidney dysfunction (estimated glomerular filtration rate, 26 mL/min/1.73 m 2 ) not requiring hemodialysis presented with effort angina. Diagnostic angiography with minimum contrast showed a diffuse lesion in the proximal right coronary artery (RCA; Figure A ). On a later day, optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) with dextran injection was performed. Because multiple cracks were seen in the severely calcified lesion after pre-dilation ( Figure B,C ; Supplementary Movie 1 ), an everolimus-eluting stent (3.25–33 mm) was implanted ( Figure D ). The final OCT showed sufficient luminal expansion (minimum stent area ...

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 ...

This study aimed to non-destructively analyze the progression of subsurface enamel caries using swept-source optical coherence tomography (SS-OCT), a recently developed imaging analysis modality. Artificial enamel caries at various stages of demineralization were created in bovine tooth enamel using a modified lactic acid gel system. Untreated enamel served as a control. OCT images from cross-sections of enamel were collected. Mineral density, distribution, and histological changes were analyzed using an electron probe microanalyzer, scanning electron microscopy, and contact microradiography. The Raman spectrum and X-ray structural analysis of the enamel surfaces were determined. SS-OCT detected significant differences in mineral loss among the ...

Optical coherence tomography (OCT) is an intravascular imaging tool. Its high resolution facilitates detailed examination of intravascular morphological characteristics. In the coronary field, OCT systems are applied as practical clinical diagnostic method. In the carotid artery field, OCT is not covered by health insurance, and it is used as a research tool. We have published many reports on the morphological characteristics of carotid artery lesions on OCT or its application for carotid artery stenting. In this article, we review the application of OCT for carotid artery plaque and its usefulness.

Abstract Background: There are few reports about the differences between drug-eluting stents (DES) and bare metal stents (BMS) in neoatherosclerosis associated with in-stent restenosis (ISR), so we compared the frequency and characteristics of neoatherosclerosis with ISR evaluated by optical coherence tomography (OCT) in the present study. Methods and Results: Between March 2009 and November 2016, 98 consecutive patients with ISR who underwent diagnostic OCT were enrolled: 34 patients had a BMS, 34 had a 1st-generation DES, and 30 had a 2nd-generation DES. Neoatherosclerosis was defined as a lipid neointima (including a thin-cap fibroatheroma [TCFA] neointima, defined as a fibroatheroma with ...

We developed an endoscopic microscopy system with 20 nm accuracy that affords inspection through narrow gaps using a thin, 1.5 mm diameter probe. Accuracy was improved using Optical Coherence Tomography (OCT). The frequency modulated light source is stabilized with closed control from self-interference measurement. The probe is driven by two miniature motors, which allow three-dimensional scanning of an internal surface. Imaging performance is 60 frames per second. The high accuracy with narrow clearance capabilities of this system reduces the need for machine overhauls, which affords trustworthy daily inspections and hence greater machine reliability.

No abstract provided.