易损斑块与急性冠脉综合征

斑块稳定性是影响急性冠脉综合征发生与发展的主要决定性因素,临床上,易损斑块破裂并发血栓形成被视为急性冠脉综合征的病理学基础。     

冠状动脉CT成像与易损斑块

冠状动脉内斑块破裂或侵蚀所致的急性腔内血栓是急性冠状动脉综合征的主要原因。防止急性血栓形成成为了降低冠状动脉粥样硬化性心脏病病死率的唯一有效策略。斑块易破裂的冠状动脉病变与稳定斑块相比,存在不同的形态学改变。因此可以利用特殊的成像方法来识别这些易损斑块。亚毫米空间分辨率和图像质量优良的现代计算机断层扫描方法可以对冠状动脉斑块进行检测、分析和量化。斑块体积较大、低CT衰减、餐巾环征、正性重构以及点状钙化等与斑块容易破裂有密切关系。将冠状动脉斑块的形态学与功能特征等相结合,在未来有可能成为检测易损斑块的新方法。现将就多层螺旋CT与冠状动脉易损斑块的检测做一综述。     

Plaque Characterization and Atherosclerosis Evaluation by Coronary Angioscopy

When observed by angioscopy, the culprit lesions of acute coronary syndrome (ACS) have a common appearance of a yellow plaque with irregular surface covered by a thrombus. Angioscopy is a powerful device to detect not only the ruptured plaques at ACS lesions but also the yellow plaques in their early stages. The culprit lesions of ACS are sometimes detected by angioscopy even in the angiographically normal segments of coronary arteries. Angioscopy can further classify the culprit lesions of ACS as (1) vasospasm, (2) plaque rupture, or (3) plaque erosion according to the angioscopic definitions. These classifications may be beneficial to determine the treatment strategy. Anti-vasospastic medications rather than stenting may be more suitable for the treatment of vasospasm-induced ACS. Percutaneous coronary intervention (PCI) of ruptured plaque rather than of erosive plaque tends to cause more distal embolization with thrombus and plaque contents. Therefore, distal protection device may be more beneficial for those cases. Although angioscopy may be able to identify vulnerable plaques as the plaques of intensive yellow color, it may be more practical to identify the patients at high risk of suffering ACS by evaluating the extent of coronary atherosclerosis. The process and the time course of plaque formation, maturation, and disruption are left to be clarified, however, the number of yellow plaques or the yellow color intensity of those plaques may be a marker of coronary atherosclerosis. Angioscopy should be useful not only as a diagnostic tool but also as an investigational tool. The effect of medications that regress coronary atherosclerosis may be evaluated by the angioscopically determined markers of coronary atherosclerosis.     

基质金属蛋白酶与冠状动脉斑块稳定性相关研究

目的 :探讨基质金属蛋白酶 1(MMP 1)、基质金属蛋白酶抑制剂 1(TIMP 1)、TIMP 1/MMP 1与冠状动脉 (冠脉 )粥样硬化斑块稳定性的相关性。方法 :以冠脉血管内超声检出冠脉粥样硬化斑块的软硬特性 ,将急性冠脉综合征患者分为不稳定斑块组 (n =2 2 )和稳定斑块组 (n =12 )。测定两组间血浆MMP 1、TIMP 1浓度 ,并与冠脉血管内超声测定的斑块大小、斑块纤维帽厚度、脂核或无回声带大小、脂核或无回声带与斑块比及面积狭窄率进行相关性分析。结果 :在冠状静脉窦血和外周血中 ,不稳定斑块组MMP 1浓度明显大于稳定斑块组 (P <0 0 1) ,TIMP 1/MMP 1明显小于稳定斑块组 (P <0 0 0 1) ,有非常显著性差异。血浆MMP 1浓度与纤维帽厚度呈负相关 ,与脂核或无回声带面积、脂核与斑块比和面积狭窄率呈正相关 ,与斑块大小无关。TIMP 1/MMP 1与纤维帽厚度、面积狭窄率呈正相关 ,与脂核或无回声带面积、脂核与斑块比呈负相关。结论 :MMP 1和TIMP 1/MMP 1与冠脉斑块不稳定性呈密切相关 ,可望作为冠脉斑块不稳定性的参考指标。     

乙酰胆碱试验诱发冠状动脉痉挛患者血管病变特点

目的临床上因冠状动脉痉挛所致具有典型或近似典型心绞痛发作患者,冠状动脉造影常无显著狭窄,本文采用血管内超声研究病变血管的特点.方法选具有典型或近似典型心绞痛发作但无心肌梗死病史患者30例,行常规定量冠状动脉造影,随后行乙酰胆碱试验及血管内超声检查,测量血管面积、管腔面积,计算斑块面积、面积狭窄率.结果30例患者中18例乙酰胆碱试验阳性,阴性12例;前降支11例(61.1%),回旋支1例(5.5%),前降支及回旋支同时发生痉挛2例(11.1%),右冠状动脉4例(22.2%).乙酰胆碱试验阳性患者冠状动脉造影示乙酰胆碱试验前最狭窄处直径为(2.66±0.54)mm,乙酰胆碱试验阳性血管直径减少了(1.72±0.38)mm.血管内超声提示所有发生痉挛的血管均有病变.15条血管内膜呈弥漫性纤维化增生,无钙化,主要病变血管为前降支,面积狭窄率为51.7%.结论血管内超声显示病变特点均为纤维增生性,基本为稳定性斑块,且为中等狭窄程度,不需介入干预.因此对于有冠状动脉痉挛所致心绞痛患者,无禁忌症应常规行乙酰胆碱诱发试验及血管内超声检查.     

Multimodality Intravascular Imaging of High-Risk Coronary Plaque

The majority of coronary atherothrombotic events presenting as myocardial infarction (MI) occur as a result of plaque rupture or erosion. Understanding the evolution from a stable plaque into a life-threatening, high-risk plaque is required for advancing clinical approaches to predict atherothrombotic events, and better treat coronary atherosclerosis. Unfortunately, none of the coronary imaging approaches used in clinical practice can reliably predict which plaques will cause an MI. Currently used imaging techniques mostly identify morphological features of plaques, but are not capable of detecting essential molecular characteristics known to be important drivers of future risk. To address this challenge, engineers, scientists, and clinicians have been working hand-in-hand to advance a variety of multimodality intravascular imaging techniques, whereby 2 or more complementary modalities are integrated into the same imaging catheter. Some of these have already been tested in early clinical studies, with other next-generation techniques also in development. This review examines these emerging hybrid intracoronary imaging techniques and discusses their strengths, limitations, and potential for clinical translation from both an engineering and clinical perspective.     

冠状动脉粥样硬化斑块内的炎症反应与CD40信号传导

冠状动脉粥样硬化斑块内的炎症反应促使冠状动脉内不稳定斑块的形成和破裂 ,在此基础上发生细胞成分的活化并介导血栓形成 ,是绝大多数急性冠状动脉综合征发生的主要原因。近年来的研究发现 ,白细胞分化抗原 40 (CD40 )信号通路参与了动脉粥样硬化斑块内主要细胞成分炎症反应的调节 ,本文对CD40信号与冠状动脉粥样硬化斑块内炎症反应的相关问题作一综述。     

血红素氧合酶-1与冠状动脉粥样硬化斑块的稳定性

随着对冠脉综合征研究的深入,我们发现冠脉病变的严重程度主要是由斑块的稳定性决定的。血红素氧合酶是血红素降解的起始酶和限速酶,能代谢血红素形成一氧化碳、游离铁和胆红素。近来研究表明血红素氧合酶-1参与了动脉粥样硬化的发生、发展,与斑块稳定性有着密切的关系。     

Atherosclerotic Carotid Plaque Composition and Incident Stroke and Coronary Events

BackgroundIncreasing evidence suggests that atherosclerotic plaque composition rather than plaque size is linked to ischemic cardiovascular events, yet largescale population-based data in asymptomatic individuals remain scarce.ObjectivesThis study sought to investigate carotid plaque composition in relation to incident stroke and coronary heart disease (CHD) in a population-based setting.MethodsBetween 2007 and 2012, 1,349 persons (mean age 72 years, 49.5% women) from the population-based Rotterdam Study who were free from a history of stroke or CHD, in whom carotid ultrasonography showed subclinical atherosclerosis, and who underwent high-resolution magnetic resonance imaging of the carotid arteries to assess plaque characteristics. These included the presence of specific plaque components (intraplaque hemorrhage [IPH], lipid-rich necrotic core, and calcification), and measures of plaque size (maximum plaque thickness and presence of stenosis of more than 30%). Individuals were continuously followed for the occurrence of stroke or CHD until January 1, 2015. The authors used Cox regression models to assess the association of the plaque characteristics with the incidence of stroke and CHD, with adjustments for age, sex, and cardiovascular risk factors.ResultsDuring a median of 5.1 years’ follow-up for stroke and 4.8 years for CHD, 51 individuals had a stroke and 83 developed CHD. Independent of maximum plaque thickness and cardiovascular risk factors, the presence of IPH was associated with incident stroke and CHD (fully adjusted hazard ratio: 2.42 [95% confidence interval: 1.30 to 4.50], and 1.95 [95% confidence interval: 1.20 to 3.14]). Presence of a lipid-rich necrotic core and calcification were not associated with stroke or CHD.ConclusionsThe presence of IPH in the carotid atherosclerotic plaque is an independent risk factor for stroke and CHD. These findings indicate the promise of IPH as a marker of plaque vulnerability in healthy persons with subclinical atherosclerosis.