光学相干断层成像在老年冠心病介入诊疗中的初步应用

目的探讨血管内光学相干断层成像（OCT）在老年冠心病介入诊疗中的作用和安全性，评价其临床价值。方法9例老年冠心病患者，行冠脉造影和OCT检查，比较二者对冠状动脉病变的显示情况：包括病变结构、管腔狭窄程度、斑块性质等，根据造影及OCT结果参照病人临床表现对于狭窄较重（造影直径狭窄率〉70％），或造影中等程度狭窄（直径狭窄率介于50％～70％），但OCT狭窄相对较重（OCT管腔面积狭窄率〉60％）并伴有不稳定斑块的病变进行球囊扩张和支架植入治疗，并用OCT评价支架植入后的即时效果。结果与冠脉造影相比，血管内OCT能直观、清晰、实时地显示病变冠脉的管腔狭窄程度、微观组织结构、斑块组成性质及支架植入后靶病变血管及支架的形态特征。结论OCT在老年冠心病患者中的操作安全易行，能够精确测量病变血管狭窄程度、清晰观测管腔微观结构特征，明确斑块特征，指导支架植入及观测支架植入后的即刻效果，对老年冠心病人介入治疗具有指导作用。     

光学干涉断层成像系统对冠心病病变特征的评价

目的:初步探讨光学干涉断层成像(OCT)系统评价冠心病病变特征的价值。方法:分析在2005年12月行冠状动脉造影检查的同时接受OCT检查的5例冠心病患者的OCT影像特征。结果:2例不稳定型心绞痛患者中,1例右冠状动脉中段成角病变狭窄99%,OCT清晰显示血栓、钙化、纤维帽厚度及脂质斑块,介入治疗后OCT检查示支架贴壁良好,血栓消失;1例前降支狭窄50%,OCT探测到清晰的附壁血栓、最薄处纤维帽及斑块破裂。3例介入治疗后患者中,1例回旋支中远段支架内狭窄75%、2例前降支支架内狭窄50%,OCT检查精确定量再狭窄程度63.33%~87.25%,增生基质主要为纤维样组织,可见少许脂质样基质,其中回旋支支架内狭窄患者OCT检查时发生支架远段冠状动脉夹层,行回旋支远段支架置入术治疗。结论:OCT系统在评价冠心病病变特征和介入治疗结果方面具有较好的应用价值。     

血管内超声与光学相干断层扫描在冠状动脉临界病变中的长期随访对比研究

目的:研究血管内超声(intravenous ultrasound,IVUS)与光学相干断层扫描(optical coher-ence tomography,OCT)在冠状动脉临界病变中的长期随访研究。方法:共入选经过冠状动脉造影(至少4体位造影)证实病变狭窄处于临界病变的患者90例。将入选者按照2∶1随机分为:血管内超声组(IVUS)60例,光学相干断层成像(OCT)组30例。通过血管内超声定量分析最小管腔直径、参考血管直径、最小管腔面积等参数指标;通过光学相干断层扫描分析最小管腔直径、最小管腔面积。同时依据两组检查方法不同特征确定斑块的性质进行定性亚组分析:纤维性斑块、钙化斑块及脂质斑块等,对于高危易损斑块进行冠状动脉介入治疗,术后规律服用药物,观察两组术后住院期间、30d、3个月、9个月、1年和2年的主要心血管事件。采用COX回归模型分析两组2年内免于心血管事件的差异。结果:IVUS和OCT进行亚组软斑块分析,两组测得最小管腔直径分别为[(1.84±0.06)vs.(1.84±0.13)mm,P=0.947]。另外,在最小管腔面积方面两组分别为[(4.7±0.98)vs.(4.8±1.17)mm2,P=0.853]。OCT组通过分析软斑块纤维帽厚度为(94±24.72)μm。通过COX回归模型显示,两组在免于心血管事件的差异无统计学意义(P=0.826)。结论:对于临界病变的患者,采用IVUS或OCT成像系统能够更好的分辨血管内斑块性质,尤其易识别易损斑块。对于临界病变的患者,采用介入影像学方法进行测量分析是安全的、可靠的,能更好指导临床治疗。     

Prevalence and Characteristics of TCFA and Degree of Coronary Artery Stenosis : An OCT,IVUS, and Angiographic Study

Background

The relationship between features of vulnerable plaque and angiographic coronary stenosis is unknown.

Objectives

The purpose of this study was to systematically investigate the absolute number, relative prevalence, and characteristics of thin-cap fibroatheroma (TCFA) at different degrees of stenosis using optical coherence tomography (OCT), intravascular ultrasound, and coronary angiography.

Methods

We identified 643 plaques from 255 subjects who underwent OCT imaging in all 3 coronary arteries. They were divided into 3 groups on the basis of angiographic diameter stenosis: Group A (30% to 49%, n = 325), Group B (50% to 69%, n = 227), and Group C (>70%, n = 91).

Results

OCT showed that the absolute number of TCFA was greatest in Group A (n = 58), followed by Groups B (n = 40) and C (n = 33). However, the relative prevalence of TCFA was higher in Group C (36%) than in Groups A (18%) or B (18%) (p = 0.003 and p = 0.002, respectively). Fibrous cap of TCFA was thinner in Group C than in Groups A (p < 0.001) or B (p = 0.001). intravascular ultrasound showed that the plaque burden of TCFA was largest in Group C (80.1 ± 7.4%), compared with Groups B (67.5 ± 9.4%) and A (58.1 ± 8.4%). TCFA in Group C had a higher remodeling index than those in Group A (p = 0.002).

Conclusions

The absolute number of TCFA is 3 times greater in nonsevere stenosis than in severe stenosis. It is, however, twice as likely for a lesion to be TCFA in cases of severe stenosis than in nonsevere stenosis. Moreover, TCFA in severely-stenotic areas had more features of plaque vulnerability.     

Infarctus du sujet jeune : à physiopathologie particulière,prise en charge singulière ?

We report the case of a 24-year-old patient admitted for anterior ST segment elevation myocardial complicated by ventricular fibrillation and revealing thrombotic sub occlusion of the left anterior descending coronary artery. Revascularization is achieved by manual thrombectomy and use of Glycoprotein GPIIbIIIa inhibitors and permits to restore TIMI 3 flow. Given the large thrombotic burden, the patient is initially treated medically (optimal anti thrombotic therapy without stenting) and benefits from angiographic control 48 hours later with imaging by Optical Coherence Tomography (OCT). It shows a reduction of thrombus burden and lack of significant underlying organic lesion (no organic stenosis or plaque rupture). In view of these data, it was decided to continue medical treatment alone without stenting. OCT imaging at 6 months shows atheroma without stenosis, thrombus or plaque rupture. This young patient remains asymptomatic and recovered normal left ventricular function with a 2-year follow-up.     

Assessment of culprit and remote coronary narrowings using optical coherence tomography with long-term outcomes

Much currently known information about vulnerable plaque stems from postmortem studies that identified several characteristics making them prone to rupture, including the presence of a thin fibrous cap and a large lipid core. This study used optical coherence tomography (OCT) to assess culprit and remote coronary narrowings and investigate whether intracoronary OCT in living patients was able to visualize morphologic features associated with vulnerable plaque in postmortem studies. Twenty-three patients successfully underwent OCT before percutaneous coronary intervention. The culprit lesion and mild to moderate coronary narrowings remote from the target stenosis were investigated. Using OCT, the culprit lesion was found to be fibrous in 39.1%, fibrocalcific in 34.4%, and lipid rich in 26.1% of cases. Two patients met criteria for thin-cap fibroatheroma (TCFA; defined as the presence of a signal-rich fibrous cap covering a signal-poor lipid/necrotic core with cap thickness <0.2 mm). Most plaques at remote segments were proximal to the culprit lesion (73.9%) and predominantly fibrous and lipid rich. OCT identified 7 TCFA lesions in 6 patients with a mean cap thickness of 0.19 +/- 0.05 mm, extending for 103 degrees +/- 49 degrees of the total vessel circumference. At 24 months of clinical follow-up, the only event occurred in a patient with in-stent restenosis who underwent repeated percutaneous revascularization. There were no clinically apparent plaque rupture-related events in the 6 patients found to have remote TCFA. This study showed that OCT can be safely applied to image beyond the culprit lesion and can detect in vivo morphologic features associated with plaque vulnerability using retrospective pathologic examination. In conclusion, detection of TCFA, particularly in stable patients, is desirable and may principally allow for early intervention and prevention of adverse events.     

Visualization of coronary atherosclerotic plaques in patients using optical coherence tomography: comparison with intravascular ultrasound

OBJECTIVES: The aim of this study was to evaluate the feasibility and the ability of intravascular optical coherence tomography (OCT) to visualize the components of coronary plaques in living patients. BACKGROUND: Disruption of a vulnerable coronary plaque with subsequent thrombosis is currently recognized as the primary mechanism for acute myocardial infarction. Although such plaques are considered to have a thin fibrous cap overlying a lipid pool, imaging modalities in current clinical practice do not have sufficient resolution to identify thin (< 65 microm) fibrous caps. Optical coherence tomography is a new imaging modality capable of obtaining cross-sectional images of coronary vessels at a resolution of approximately 10 microm. METHODS: The OCT images and corresponding histology of 42 coronary plaques were compared to establish OCT criteria for different types of plaques. Atherosclerotic lesions with mild to moderate stenosis were identified on angiograms in 10 patients undergoing cardiac catheterization. Optical coherence tomography and intravascular ultrasound (IVUS) images of these sites were obtained in all patients without complication. RESULTS: Comparison between OCT and histology demonstrated that lipid-rich plaques and fibrous plaques have distinct OCT characteristics. A total of 17 IVUS and OCT image pairs obtained from patients were compared. Axial resolution measured 13 +/- 3 microm with OCT and 98 +/- 19 microm with IVUS. All fibrous plaques, macrocalcifications and echolucent regions identified by IVUS were visualized in corresponding OCT images. Intimal hyperplasia and echolucent regions, which may correspond to lipid pools, were identified more frequently by OCT than by IVUS. CONCLUSIONS: Intracoronary OCT appears to be feasible and safe. Optical coherence tomography identified most architectural features detected by IVUS and may provide additional detailed structural information.     

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.     

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.     

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.     

Regression of a large lipid-rich pool in the coronary artery during treatment with statin detected by intravascular ultrasound: a case report

A 54-year-old man with unstable angina presented with severe stenosis of the middle segment of the left anterior descending coronary artery. Percutaneous coronary stent implantation and serial intravascular ultrasound (IVUS) were performed. IVUS detected a non-culprit coronary plaque with a large lipid-rich pool in the proximal segment of the left anterior descending coronary artery. Atorvastatin 10 mg/day was given to reduce his cholesterol level for 2 years after the stent implantation. This patient had no cardiac events, and the low-density lipoprotein-cholesterol level reduced from 171 to 88 mg/dl at follow-up. Two-year follow-up IVUS examination revealed the reduction of plaque burden associated with regression of the lipid-rich pool size. This case may indicate that statin could contribute to the regression of lipid-rich plaque and to the stability of coronary plaque.     

光学相干断层成像在检测易损斑块中的应用价值

冠状动脉粥样硬化斑块易发斑块破裂,导致急性冠状动脉综合征,引起急性心肌梗死。有效的评价斑块的结构及成份特点,监测其演变过程,对选择治疗时机和治疗方案有重要意义。光学相干断层成像是一种新型的生物医学成像技术,它可以对易损斑块准确识别。现就光学相干断层成像在检测易损斑块中的应用价值作一综述。     

CT血管造影在冠状动脉狭窄程度及其斑块类型评估中的应用价值

背景 CT血管造影(CTA)已成为影像学研究的热点,近年被越来越多地应用于临床.目的 探讨CTA在冠状动脉狭窄程度及其斑块类型评估中的应用价值.方法 选取东南大学附属中大医院江北院区2018年8月至2020年8月收治的冠心病(CHD)患者98例,均接受CAG和CTA检查.记录CTA对冠状动脉管腔的评价结果,以CAG为诊...     

光学相干断层成像检测家兔腹主动脉易损斑块的实验研究

目的评价光学相干断层成像(optical coherence tomography,OCT)在检测易损斑块中的应用价值。方法选取30只雄性纯种的新西兰大白兔,随机分为球囊损伤组(建立家兔腹主动脉易损斑块模型),高脂对照组及正常对照组,每组10只。前2组高脂喂养,喂养12周后,分别给予中国斑点蝰蛇毒和组胺药物触发,诱发斑块破裂及血栓形成后进行OCT,并与病理结果对照检测OCT效果。结果球囊损伤组存活的8只白兔中有10处病变狭窄程度>50%,脂质核心较大、纤维帽厚度>65μm,判定以上10处病变为易损斑块;高脂对照组存活的9只白兔仅3处可判定为易损斑块;正常对照组中未见易损斑块。3组102个OCT图像与病理检测动脉内膜厚度[(20.2±7.6)μmvs(15.2±0.9)μm]、中膜厚度[(453.81±87.2)μmvs(434.2±86.5)μm]、斑块厚度[(392.2±34.5)μmvs(380.2±57.1)μm]比较,差异无统计学意义(P>0.05)。OCT测量球囊损伤组易损斑块和稳定斑块血管外弹力膜面积[(16.01±4.44)μmvs(10.32±2.44)μm]和斑块面积[(8.08±2.37)μmvs(6.80±2.17)μm]比较,差异有统计学意义(P<0.01)。结论 OCT是一种判定易损斑块病变特征的有效手段,可以诊断易损斑块、指导临床制定治疗策略。     

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。     

A Survey on Coronary Atherosclerotic Plaque Tissue Characterization in Intravascular Optical Coherence Tomography

Purpose of Review

Atherosclerotic plaque deposition within the coronary vessel wall leads to arterial stenosis and severe catastrophic events over time. Identification of these atherosclerotic plaque components is essential to pre-estimate the risk of cardiovascular disease (CVD) and stratify them as a high or low risk. The characterization and quantification of coronary plaque components are not only vital but also a challenging task which can be possible using high-resolution imaging techniques.

Recent Finding

Atherosclerotic plaque components such as thin cap fibroatheroma (TCFA), fibrous cap, macrophage infiltration, large necrotic core, and thrombus are the microstructural plaque components that can be detected with only high-resolution imaging modalities such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT). Light-based OCT provides better visualization of plaque tissue layers of coronary vessel walls as compared to IVUS. Three dominant paradigms have been identified to characterize atherosclerotic plaque components based on optical attenuation coefficients, machine learning algorithms, and deep learning techniques.

Summary

This review (condensation of 126 papers after downloading 150 articles) presents a detailed comparison among various methodologies utilized for plaque tissue characterization, classification, and arterial measurements in OCT. Furthermore, this review presents the different ways to predict and stratify the risk associated with the CVD based on plaque characterization and measurements in OCT. Moreover, this review discovers three different paradigms for plaque characterization and their pros and cons. Among all of the techniques, a combination of machine learning and deep learning techniques is a best possible solution that provides improved OCT-based risk stratification.

     

Neo-atherosclerosis in very late stent thrombosis of drug eluting stent

Background

Recent studies have described neo-atherosclerosis, developing inside the stent, as cause of very late stent thrombosis.

Case report

A 59-year-old man, with family history of coronary artery disease, presented to our Department because of anterior ST-segment elevation myocardial infarction. Two years before he had underwent percutaneous coronary intervention with multiple drug-eluting stents (DES) implantation on proximal-mid left anterior descending artery (LAD), and mid-right coronary artery (RCA), respectively. The angiogram revealed stent thrombosis with total occlusion of proximal LAD. Multiple passages with manual thrombus-aspiration catheter were successfully performed with improvement in TIMI flow. Optical Coherence Tomography (OCT) imaging revealed fully expanded stents without areas of inappropriate apposition to vessel wall; and mild to moderate intimal hyperplasia throughout the stented segment, with full covered stent struts; areas of ulcerated and ruptured plaque within the proximal struts of stented segment was depicted with intraluminal protruding material. Thus, an additional bare metal stent (BMS) was deployed inside and overlapping the previous in order to seal this plaque. OCT post procedure revealed optimal stent expansion and apposition, without residual protruding material. At 9-month follow-up patient was alive and free from symptoms. Coronary angiogram revealed patency of implanted stents without significant restenosis.

Conclusions

Neo-atherosclerosis with thrombosis on top of ruptured necrotic plaque core may play a role in the pathophysiology of very late stent thrombosis in both BMS and DES. Our report highlights the role OCT to assess the mechanism of VLST.     

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。     

Axial plaque redistribution after coronary stent deployment

We report a case of axial plaque redistribution after coronary stent deployment assessed by intravascular ultrasound (IVUS) as well as coronary angiography. A 72-year-old male with a history of hypertension, hyperlipidemia and a nuclear stress test demonstrating anterior and lateral ischemia was admitted for cardiac catheterization. Coronary angiography and IVUS examination revealed eccentric stenoses in the left anterior descending artery (LAD) and the left circumflex artery (LCx), just before the bifurcation of the first obtuse marginal branch. After successful LAD stent placement, the LCx was also stented, jailing the obtuse marginal branch. Immediately after dilatation, however, the coronary angiogram showed a new significant stenosis at the distal adjacent segment. IVUS examination after administration of nitroglycerin revealed a secondary critical lesion that was not observed before the interventional procedure. A significant plaque increase at the new lesion site presumably resulted from axial plaque redistribution (extrusion from the stented segment, otherwise known as plaque shift). After additional stenting, the patient had an uneventful course.