光学相干断层成像对急性冠状动脉综合征患者易损斑块的新认识

血管斑块的稳定性是影响急性冠状动脉综合征发生发展的主要因素,具有超高空间分辨率的光学相干断层成像(OCT)技术在易损斑块识别方面有着独特的优势。本文就近年来OCT在急性冠状动脉综合征患者易损斑块识别方面的临床新进展进行综述。     

冠状动脉易损斑块评价方法研究进展

冠状动脉粥样硬化是冠心病最主要的病因,易损斑块是冠状动脉粥样硬化的主要表现形式。早期识别冠状动脉易损斑块对于预防急性心血管事件的发生具有重要意义。现就冠状动脉易损斑块评价方法如血管内超声(IVUS)、光学相干断层成像(OCT)、冠状动脉多层CT(MSCT)、MRI、炎症指标等研究进展做一综述。     

冠状动脉易损斑块的识别和防治进展

易损斑块的早期识别对于治疗及预后具有重要的价值,现有的影像学诊断方法包括靶向分子荧光成像、冠状动脉(冠脉)计算机断层摄影术(CT)造影、磁共振、血管内超声(包括虚拟组织学成像)、光学相干断层成像及血管内窥镜等,而血清学检查还没有一个很好的指标提示易损斑块。易损斑块的治疗主要是他汀类药物治疗,强化降脂治疗可以起到逆转斑块的作用,而其它稳定易损斑块的治疗方法还需要进一步研究证实。     

光学相干断层成像技术对冠状动脉斑块应用的进展

冠状动脉内光学相干断层成像技术(OCT)的应用可以提供精确的斑块形态学特征,识别易损病变,优化支架植入并指导血运重建策略。其对于易损斑块的识别为个性化风险的评估铺平道路,并为改善临床预后提供可能。本文就OCT对冠脉斑块的应用作一综述。     

光学相干断层成像评价易损斑块的应用进展

急性心血管事件是致死率极高的疾病,粥样斑块破裂后血栓形成被认为是许多急性心血管事件的直接原因。在过去几十年里,光学相干断层成像(OCT)逐渐被运用于准确识别易损斑块,OCT是一种利用光学原理的血管内成像新技术,具有高分辨率及良好的组织相关性。现就将OCT评价易损斑块的应用进展做一综述。     

光学相干断层成像技术在急性冠脉综合征中的应用进展

光学相干断层成像是一种新的血管内成像方法。由于其良好的图像分辨率,能更为精确地分辨粥样斑块的细节特征,成为识别易损斑块,判断支架贴壁情况及支架内再狭窄和血栓形成的一种新手段,在急性冠脉综合征诊断和指导治疗中有巨大的应用价值。     

光学相干断层成像技术在冠状动脉内应用的研究进展

光学相干断层成像技术(OCT)是目前分辨率最高的腔内影像技术,在评估急性冠状动脉(冠脉)综合征患者罪犯病变斑块的特征、易损斑块、钙化斑块、支架内膜覆盖情况,以及支架内再狭窄、指导冠脉介入治疗和用药等方面有独特的优势。现就OCT的研究进展进行综述。     

光学相干断层成像技术在检测动脉粥样硬化病变中的应用

光学相干断层成像（optical coherence tomography,OCT）是一种新的高分辨率断面成像模式,它将新发展的光学技术与超灵敏探测合为一体,加上现代计算机图像处理,发展成为一门新兴的断层成像诊断技术。易损斑块是指所有易于发生血栓的斑块和十分可能迅速进展成为罪犯斑块的种种斑块。但现有的筛查和诊断的方法不足以在急性心血管病事件发生之前将易损斑块识别出来。此外,动脉粥样斑块从稳定变为易损的过程涉及炎症、免疫、代谢、凝血等多个环节,单纯显示动脉管腔或斑块形态的诊断技术已不能满足临床的需要。因此,OCT技术在识别动脉粥样斑块成分、鉴别易损斑块和指导介入治疗过程等方面的作用备受关注并得到广泛的研究。     

光学相干断层成像判断冠状动脉不稳定斑块

光学相干断层成像是近年出现的一项光学成像技术,其原理是基于光学干涉现象。该项技术与血管内超声相比具有更高的分辨率,本文根据光学相干断层成像在心血管疾病领域的研究进展,总结了该项技术对冠状动脉不稳定斑块方面的研究现状。     

光学相干断层成像评价经皮冠状动脉内支架术后即刻效果

冠状动脉内光学相干断层成像（OCT）是近几年发展起来的一种具有高分辨率和对比度的冠状动脉断层成像技术，其分辨率达10，比目前所有已知的冠状动脉成像检查方法高10倍以上，可以显示冠状动脉病变以及介入治疗后支架周围超微结构的改变。我中心自2005年8月开展OCT检查技术，初步研究结果显示该项检查安全有效，能够分辨斑块的细节特征，识别易损斑块，为介入治疗提供决策依据。本研究的目的是利用OCT分析冠状动脉支架置入术后支架周围超微结构特征。     

Intracoronary imaging using attenuation-compensated optical coherence tomography allows better visualisation of coronary artery diseases

PurposeTo allow an accurate diagnosis of coronary artery diseases by enhancing optical coherence tomography (OCT) images of atheromatous plaques using a novel automated attenuation compensation technique.BackgroundOne of the major drawbacks of coronary OCT imaging is the rapid attenuation of the OCT signal, limiting penetration in tissue to only few millimetres. Visualisation of deeper anatomy is however critical for accurate assessment of plaque burden in-vivo.MethodsA compensation algorithm, previously developed to correct for light attenuation in soft tissues and to enhance contrast in ophthalmic OCT images, was applied to intracoronary plaque imaging using spectral-domain OCT.ResultsApplication of the compensation algorithm significantly increased tissue contrast in the vessel wall and atherosclerotic plaque boundaries. Contrast enhancement allows a better differentiation of plaque morphology, which is particularly important for the identification of lipid rich fibro atheromatous plaques and to guide decision on treatment strategy.ConclusionThe analysis of arterial vessel structure clinically captured with OCT is improved when used in conjunction with automated attenuation compensation. This approach may improve the OCT-based interpretation of coronary plaque morphology in clinical practice.     

光学相干断层显像在冠状动脉介入治疗中的应用

光学相干断层显像是利用近红外光成像技术,能提供高质量血管内图像。这项技术已经应用于冠状动脉介入治疗。现就光学相干断层显像技术在冠状动脉介入治疗中的作用进行综述。     

Clinical applications of optical coherence tomography

Rupture of vulnerable plaque (VP) is responsible for most coronary events. Optical coherence tomography (OCT) is a high-resolution imaging method that allows excellent characterization of atherosclerotic plaque. While this technique is limited by the need to interrupt blood flow and a shallow depth of penetration, its resolution is an order of magnitude greater than possible with intravascular ultrasound (IVUS), and it has demonstrated better sensitivity and specificity for accurately determining plaque composition. Early in vitro and in vivo experiences have affirmed the excellent quality of these images making it an attractive technology for the analysis of VP. Its high resolution likely renders it the best imaging modality currently available for the evaluation of proper stent deployment and of intracoronary pathology in the setting of percutaneous coronary interventions (PCI). Our institution is currently involved in a multicenter trial to evaluate the effectiveness of OCT when compared to IVUS in this setting. Ongoing technological improvements aim to permit rapid scanning which should alleviate its current major limitation of needing to scan in a blood-free space. OCT is a promising new technology in the evaluation of atherosclerotic plaque and coronary microstructure.     

The diagnostic value of intracoronary optical coherence tomography

Optical coherence tomography (OCT) is a novel light-based imaging modality for application in the coronary circulation. Compared to conventional intravascular ultrasound, OCT has a ten-fold higher image resolution. This advantage has seen OCT successfully applied in the assessment of atherosclerotic plaque, stent apposition, and tissue coverage, heralding a new era in intravascular coronary imaging. The present article discusses the diagnostic value of OCT, both in cardiovascular research as well as in potential clinical application.The unparalleled high image resolution and strong contrast between the coronary lumen and the vessel wall structure enable fast and reliable image interpretation. OCT makes it possible to visualize the presence of atherosclerotic plaque in order to characterize the structure and extent of coronary plaque and to quantify lumen dimensions, as well as the extent of lumen narrowing, in unprecedented detail. Based on optical properties, OCT is able to distinguish different tissue types, such as fibrous, lipid-rich, necrotic, or calcified tissue. Furthermore, OCT is able to cover the visualization of a variety of features of atherosclerotic plaques that have been associated with rapid lesion progression and clinical events, such as thin cap fibroatheroma, fibrous cap thickness, dense macrophage infiltration, and thrombus formation. These unique features allow the use of OCT to assess patients with acute coronary syndrome and to study the dynamic nature of coronary atherosclerosis in vivo and over time. This permits new insights into plaque progression, regression, and rupture, as well as the study of effects of therapies aimed at modulating these developments.Today's OCT technology allows high detail resolution as well as fast and safe clinical image acquisition. These unique features have established OCT as the gold standard for the assessment of coronary stents. This technique makes it possible to study stent expansion, peri-procedural vessel trauma, and the interaction of the stent with the vessel wall down to the level of individual stent struts, both acutely as well as in the long term, where it is has proven extremely sensitive to the detection of even minor amounts of tissue coverage. These qualities render OCT indispensable to addressing vexing clinical questions such as the relationship of drug-eluting stent deployment, vascular healing, the true time course of endothelial stent coverage, and late stent thrombosis. This may also better guide the optimal duration of dual anti-platelet therapy that currently remains unclear and relatively empirical.In the future, OCT might emerge, parallel to its undisputed position in research, as the tool of choice in all clinical scenarios where angiography is limited by its nature as a two-dimensional luminogram.     

Optical coherence tomography: clinical applications and the evaluation of DES

Optical coherencet tomography (OCT) is a light-based imaging modality that can provide in vivo high-resolution images of the coronary artery. In the last years there has been a continuous technical development that has improved the image quality and has simplified the acquisition procedure in order to spread the clinical applicability of this technique. Due to its high resolution OCT, can be a very valuable tool for the evaluation of the coronary vessel wall, the acute and long-term impact of catheter-based intervention on plaque structure and vessel architecture and the assessment of stents. During stenting, OCT offers the possibility to evaluate stent apposition in great detail and can identify the presence of vessel injury due to stent implantation. At follow-up, the tissue coverage of individual struts can be imaged with OCT. This is of increasing interest in drug-eluting stents in which the neointimal proliferation is inhibited to such extent that it might not be visualized with conventional intracoronary imaging techniques such as IVUS. Regarding the analysis of the coronary vessel wall, OCT holds promise for the identification of thin cap fibroatheroma due to its ability to provide information about plaque composition, presence of macrophages and thickness of the fibrous cap.     

光学相干断层成像在冠心病介入治疗中的应用价值

目的应用光学相干断层成像（OCT）技术评价冠状动脉内粥样硬化斑块、血管对置入支架后即刻和中远期的反应。方法20例冠心病患者,有22支血管在完成冠状动脉造影或介入治疗后进行OCT成像。同时获取23个支架OCT成像,在23个支架中有15个为支架术后4～35个月随访,其中7个为雷帕霉素药物洗脱支架,8个为金属裸支架,另外8个为支架置放后即刻成像。结果入选的20例患者均成功进行OCT检查,并获取22支血管和23个支架满意的图像。通过OCT成像清晰地显示8处纤维斑块、3处钙化斑块、9处富含脂质斑块、2处血栓形成、斑块破裂3处及血管壁上夹层、粥样硬化斑块微小裂口和夹层等。7个置入雷帕霉素药物洗脱支架后OCT随访,均未发现有明显再狭窄,支架表面有少量内膜覆盖,部分支架表面没有内膜覆盖,其中1个支架血管出现瘤样扩张、支架与血管壁分离、支架表面没有内膜覆盖,有1个支架没有充分扩张。8个金属裸支架后用OCT随访发现,所有置入金属裸支架后支架表面内膜增殖明显,其中有3个支架因为内膜过度增殖而出现再狭窄,并再次接受介入治疗。8个支架术后即刻OCT检查显示,与血管贴壁均良好、支架扩张充分有3个支架,4个支架充分扩张,但可见到斑块裂片通过支架网眼突入管腔,1个支架支撑杆分布不均,可见支架与血管壁分离,在8个支架中有2个为支架内套叠支架。结论OCT成像技术可清晰显示各种冠状动脉粥样斑块情况,并可用于评价冠状动脉介入治疗的效果。     

Assessment of coronary plaque with optical coherence tomography and high-frequency ultrasound

This study compares the ability of intravascular optical coherence tomography (OCT) and high-frequency intravascular ultrasound (IVUS) to image highly stenotic human coronary arteries in vitro. Current imaging modalities have insufficient resolution to perform risk stratification based on coronary plaque morphology. OCT is a new technology capable of imaging at a resolution of 5 to 20 microm, which has demonstrated the potential for coronary arterial imaging in prior experiments. Human postmortem coronary arteries with severely stenotic segments were imaged with catheter-based OCT and IVUS. The OCT system had an axial resolution of 20 microm and a transverse resolution of 30 microm. OCT was able to penetrate and image near-occlusive coronary plaques. Compared with IVUS, these OCT images demonstrated superior delineation of vessel layers and lack of ring-down artifact, leading to clearer visualization of the vessel plaque and intima. Histology confirmed the accuracy and high contrast of vessel layer boundaries seen on OCT images. Thus, catheter-based OCT systems are able to image near-occlusive coronary plaques with higher resolution than that of IVUS.     

In-vivo comparison of coronary plaque characteristics using optical coherence tomography in women vs. men with acute coronary syndrome

OBJECTIVE: Women with acute coronary syndromes (ACS) have worse outcomes than men. Data on sex differences of culprit plaque characteristics are lacking. Intravascular optical coherence tomography (OCT) is a high-resolution imaging technique capable of in-vivo plaque characterization. The aim of this study was to compare culprit plaque characteristics in women and men presenting with ACS. METHODS: Patients undergoing coronary angiography after ACS were enrolled. We performed OCT imaging on the culprit lesions. Previously validated criteria for OCT plaque characterization were used: lipid was quantified on cross-sectional image and lipid-rich plaque was defined as > or = 2 involved quadrants; fibrous cap thickness was measured at the thinnest point and thin-cap fibroatheroma was defined as lipid-rich plaque with fibrous cap thickness less than 65 microm. RESULTS: Forty-two patients (33 men and nine women) were included. No significant sex differences were found in baseline characteristics. Lipid-rich plaques were identified in majority of patients. No significant difference, however, was seen in the frequency of lipid-rich plaques, thin-cap fibroatheroma or minimum fibrous cap thickness (79 vs. 89%; 45 vs. 67%; 53.8 vs. 45.4 microm, respectively; P=NS) between men and women. Incidence of calcification, thrombus and plaque disruption were also similar. CONCLUSIONS: No significant sex difference was seen in culprit plaque characteristics determined by OCT imaging in patients who presented with ACS.     

Lipid rich plaque, female gender and proximal coronary stent edge dissections

We hypothesized that women are more prone to develop coronary dissections during PCI due to potential balloon-oversizing or gender specific plaque and vascular characteristics. To date, a gender related difference in edge dissection has not been systematically studied. The Massachusetts General Hospital Optical Coherence Tomography (MGH OCT) Registry is an international registry of patients undergoing OCT procedures. We identified 206 consecutive patients (159 men, 47 women) with stable or unstable coronary syndromes demonstrating adequate OCT images for gender specific comparison in areas of non-overlapping stents. Presence of proximal edge dissection, its characteristics, plaque composition at stent borders and luminal diameters were assessed. A multivariate logistic regression model was applied to determine if female gender was predictive of proximal coronary dissection after adjusting for clinical, procedural and plaque characteristics. Proximal coronary dissection was significantly more common in women as compared to men (30.6 vs 15.6 %, p = 0.02). No gender differences were observed in age, presentation, and stents per patient or plaque characteristics. The characteristics of edge dissections were different in women compared to men with a significant female predisposition to more complex proximal coronary dissection. In multivariable analysis, female gender was not a predictor of coronary dissection; on the other hand, stent oversizing and especially lipid rich plaque at proximal edge were independent predictors of proximal dissection. OCT confirms that female gender is associated with a greater than twofold increased risk of developing proximal coronary edge dissections as compared to men. But, the most potent independent predictor of proximal coronary edge dissection is the presence of a proximal lipid rich plaque.     

OCT对冠状动脉介入术后即刻支架周围组织结构改变的评价

目的通过光学相干断层成像(OCT)初步评价冠状动脉内支架术后即刻支架周围组织结构特点。方法随机入选15例冠状动脉粥样硬化性心脏病(冠心病)行支架置入术患者,在患者置入支架后用OCT成像系统评价术后即刻支架释放情况及支架贴壁情况。结果15例患者共置入36枚支架,OCT检查得到满意图像并显示有14例患者冠状动脉内支架各部分充分释放,支架与血管壁贴合良好,无斑块组织向血管腔内突入,支架连接处贴合好;有1例患者支架部分节段释放不充分,支架与血管壁贴合不良,支架连接处贴合欠佳。结论OCT检查可充分评价支架释放及血管壁贴合和支架连接处管壁贴合情况,是检查支架术后支架周围组织结构的一种重要方法。