The Role of Optical Coherence Tomography in Coronary Intervention

Optical coherence tomography (OCT) is an optical analog of intravascular ultrasound (IVUS) that can be used to examine the coronary arteries and has 10-fold higher resolution than IVUS. Based on polarization properties, OCT can differentiate tissue characteristics (fibrous, calcified, or lipid-rich plaque) and identify thin-cap fibroatheroma. Because of the strong attenuation of light by blood, OCT systems required the removal of blood during OCT examinations. A recently developed frequency-domain OCT system has a faster frame rate and pullback speed, making the OCT procedure more user-friendly and not requiring proximal balloon occlusion. During percutaneous coronary intervention (PCI), OCT can provide detailed information (dissection, tissue prolapse, thrombi, and incomplete stent apposition [ISA]). At follow-up examinations after stent implantation, stent strut coverage and ISA can be assessed. Several OCT studies have demonstrated delayed neointimal coverage following drug-eluting stent (DES) implantation vs. bare metal stent (BMS) placement. While newer DESs promote more favorable vascular healing, the clinical implications remain unknown. Recent OCT studies have provided insights into restenotic tissue characteristics; DES restenotic morphologies differ from those with BMSs. OCT is a novel, promising imaging modality; with more in-depth assessments of its use, it may impact clinical outcomes in patients with symptomatic coronary artery disease

Different Patterns of Vascular Response Between Patients With or Without Diabetes Mellitus After Drug-Eluting Stent Implantation Optical Coherence Tomographic Analysis

ObjectivesWe performed this study to investigate with optical coherence tomography (OCT) the vascular response after sirolimus-eluting stent (SES) implantation between patients with and those without diabetes mellitus (DM).BackgroundThe difference in vascular response after SES implantation between patients with and those without DM has not been fully evaluated with OCT.MethodsOptical coherence tomography was performed to examine 74 nonrestenotic SES implanted in 63 patients (32 with DM and 31 without DM) at 9 months after SES implantation. For struts showing neointimal coverage, the neointimal thickness on the luminal side of each strut section was measured, and neointimal characteristics were classified into high, low, and layered signal pattern.ResultsBaseline patient characteristics and lesion and procedural characteristics data were similar between the 2 groups. In total, 11,422 struts were analyzed. High signal neointima was observed in 90.2 ± 13.9%, low signal neointima in 7.3 ± 10.0%, and layered neointima in 2.7 ± 5.8%/stents. There was higher incidence of low signal neointima (10.5 ± 10.3% vs. 4.5 ± 5.6%, p = 0.003), neointimal thickness was larger (median: 106.8 μm, interquartile range: 79.3 to 130.4 μm vs. median: 83.5 μm, interquartile range: 62.3 to 89.3 μm; p < 0.0001), and neointimal coverage of stent struts was higher (92.1 ± 6.2% vs. 87.2 ± 11.9%; p = 0.03) in DM patients.ConclusionsHigh signal neointimal pattern was predominantly observed, and low or layered signal pattern was observed in some cases. In DM patients, low signal neointima was observed with high frequency. Neointimal coverage and neointimal thickness was also higher in DM patients as compared with non-DM patients

The Efficacy of a Bilateral Approach for Treating Lesions With Chronic Total Occlusions The CART (Controlled Antegrade and Retrograde subintimal Tracking) Registry

ObjectivesThe aim of this study was to evaluate the safety and feasibility of a new concept for chronic total occlusion (CTO) recanalization—using a bilateral approach that utilizes a Controlled Antegrade and Retrograde subintimal Tracking (CART) technique.BackgroundSuccessful percutaneous recanalization of coronary CTOs results in improved long-term outcomes. The recanalization of CTOs in native coronary arteries no doubt represents one of the most technically challenging of interventional procedures.MethodsA total of 224 consecutive patients (mean age 61 ± 9 years; 86.2% men) were enrolled in this prospective multicenter registry. This technique combines the simultaneous use of antegrade and retrograde approaches. A subintimal dissection is created in both antegrade and retrograde fashion, thereby limiting the extension of the subintimal dissection within the CTO portion.ResultsOf 224 CTO lesions (>3 months in duration) undergoing attempted recanalization using the CART technique, 145 cases (64.7%) had undergone previous CTO recanalization attempts. The success rates of crossing in a retrograde fashion with a wire and a balloon were 87.9% and 79.9%, respectively. The overall technical and procedural success rates achieved in this registry were 92.4% and 90.6%, respectively.ConclusionsA bilateral approach for CTO lesions using the CART technique is feasible, safe, and has a higher success rate than previous approaches. These results indicate that a bilateral technique can solve a major dilemma that commonly affects CTO procedures

Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies

Objectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease. Background: Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of ∼10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and the interest in using this technology is growing. Incorporation of IVOCT in research and daily clinical practice can be facilitated by the development of uniform terminology and consensus-based standards on use of the technology, interpretation of the images, and reporting of IVOCT results. Methods: The IWG-IVOCT, comprising more than 260 academic and industry members from Asia, Europe, and the United States, formed in 2008 and convened on the topic of IVOCT standardization through a series of 9 national and international meetings. Results: Knowledge and recommendations from this group on key areas within the IVOCT field were assembled to generate this consensus document, authored by the Writing Committee, composed of academicians who have participated in meetings and/or writing of the text. Conclusions: This document may be broadly used as a standard reference regarding the current state of the IVOCT imaging modality, intended for researchers and clinicians who use IVOCT and analyze IVOCT data

Relationship Between Coronary Plaque Formation and NAD(P)H Oxidase-derived Reactive Oxygen Species : Comparison of Intravascular Ultrasound Finding of Atherosclerotic Lesions with Histochemical Characteristics

Background: Oxidative stress induced by reactive oxygen species (ROS) in the vesselwall plays an essential role in atherogenesis. Recently, we demonstrated that thegeneration of ROS via NAD(P)H oxidase was correlated with plaque instability usingcoronary specimens obtained by directional coronary atherectomy (DCA). In this study,the relation between plaque formation and ROS generation was studied based onpre-interventional examination with intravascular ultrasound (IVUS) and histologicalanalysis of the corresponding DCA specimens.Methods: Pre-interventional IVUS images of 29 patients were analyzed. Vesselcross-sectional area (CSA), lumen CSA, plaque CSA and % plaque area were obtainedat the minimal lumen site. ROS generation and expression of NAD(P)H oxidase p22 phoxin DCA specimens were evaluated by the dihydroethidium method andimmunohistochemistry as the ratio of positive area versus total surface area in eachspecimen.Results: ROS positive area ratio in DCA specimens was correlated positively withvessel CSA, plaque CSA, and % plaque area (r = 0.51, p = 0.0046; r = 0.62, p = 0.0004;r = 0.60, p = 0.0006, respectively). Further, p22 phox positive area ratio in DCAspecimens was also correlated with vessel CSA and plaque CSA (r = 0.47, p = 0.0095; r= 0.47, p = 0.0103, respectively).Conclusions: This in vivo study clearly demonstrates that NAD(P)H oxidase-derivedROS plays a significant role in the development of atherosclerosis