Assessment of plaque vulnerability by angioscopic classification of plaque color

Background

The disruption of yellow plaque and subsequent thrombosis is regarded as the mechanism of acute coronary syndrome. However, there are limited reports on the assessment of plaque vulnerability. Therefore, we tested whether the angioscopically determined yellow color intensity of plaque is associated with the prevalence of thrombosis on the plaque.

Methods

The angioscopic images of 843 patients who underwent catheterization and angioscopic examination from November 1999 to July 2003 for the diagnosis of coronary artery diseases were analyzed. Suspected culprit vessel was observed by angioscopy, and the yellow color intensity (1, light yellow; 2, yellow; 3, intensive yellow) of all yellow plaques (n = 1253) detected in the nonstenotic (diameter stenosis <50%) coronary segments was determined, as well as whether there was thrombosis on the plaques.

Results

The number of detected yellow plaques was 345, 721, and 187 for color grade 1, 2, and 3, respectively. The prevalence of thrombosis detected by angioscopy (15%, 26%, and 52% on the plaque of color grade 1, 2, and 3, respectively, P < .0001) was significantly higher on the plaque of higher yellow color grade.

Conclusions

The yellow color intensity of plaque determined by angioscopy was strongly related with the prevalence of thrombosis on the plaque. The yellow color intensity may be a marker of plaque vulnerability.     

Pathophysiology of plaque rupture and the concept of plaque stabilization

Atherosclerotic coronary artery disease is the major cause of death, in men and women, in the United States and in much of the Western world. Atherosclerosis is responsible for coronary heart disease, limb ischemia, and most strokes. Although luminal narrowing by an atherosclerotic plaque and exaggerated or anomalous vasoconstriction contribute to some of the clinical manifestations of atherosclerotic arterial disease, it is the superim-position of a thrombus over an underlying ruptured or eroded plaque that results in the acute coronary syndromes (unstable angina, acute myocardial infarction, and sudden death) that are the most serious clinical manifestations of this disease.     

血小板致动脉粥样硬化斑块形成的相关研究

在动脉粥样硬化斑块形成和血脂紊乱的基础上,常伴随着血小板的异常激活。血小板参与了动脉粥样硬化斑块形成的全部过程,即血小板本身具有致斑块性,血小板参与体内血脂调节、促炎症及致氧化应激作用。该文介绍血小板致动脉粥样硬化斑块形成的机制和相关临床研究。     

冠状动脉血栓形成的病理生理学——斑块破裂和斑块糜烂的作用

本文综述了冠状动脉粥样硬化血栓形成的病理生理学 ,斑块破裂和斑块糜烂在冠状动脉血栓形成中的作用 ,斑块破裂的机制和稳定斑块的治疗原则     

斑块内血管生成在兔动脉粥样硬化斑块发生发展中的作用

目的观察斑块内血管生成对兔动脉粥样硬化斑块形成与发展的影响。方法用高胆固醇饲料复制动脉粥样硬化兔模型。15只日本大耳白兔随机分为3组:A组,阴性对照组,仅给普通饲料喂养,B、C组给高胆固醇饲料喂养3周,A组及B组肌注白蛋白(2μg/kg)(0d),C组肌注血管内皮生长因子(VEGF1652μg/kg),继续以前饲养方式3周处死动物,截取胸主动脉进行计量组织学及免疫组织化学分析,测定不同组别不同时间点兔血清白细胞介素8(IL8)浓度和血脂浓度。结果(1)斑块面积(A组0,B组1.81%±0.61%,C组24.12%±3.58%)、斑块周径(A组0,B组6.05%±1.62%,C组25.71%±1.97%)及斑块的最大厚度(A组0,B组0.06mm±0.002,C组0.16mm±0.007mm),各组间比较有显著差异(P<0.05)。(2)新生血管的密度(CD34阳性细胞数细胞数/mm2(cells/mm2)A组0,B组12.35±2.02,C组61.15±7.55)各组之间比较有显著差异(P<0.05)。(3)电镜显示:新生血管与动脉粥样斑块相邻,新生血管腔内可见淋巴细胞。(4)血清IL8浓度(+21d时A组[0.05±0.006]pg/ml,B组[0.808±0.308]pg/ml,C组[15.72±4.31]pg/ml)各组间相比有显著差异。(5)此时血清胆固醇浓度B,C两组相比无显著差异。结论斑块内血管生成是动脉粥样斑块的重要病理特征,这个过程可能与炎性反应有关。     

Atherosclerotic plaque biomarkers: beyond the horizon of the vulnerable plaque

Cardiovascular disease (CVD) is the number one cause of death globally, and the majority of CVD is caused by atherosclerosis. Atherosclerosis is a systemic inflammatory disease that leads to myocardial infarction, stroke and lower limb ischemia. Pathological studies have given insight to development of atherosclerosis and the importance of local plaque vulnerability, leading to thrombus formation and cardiovascular events. Due to the burden of cardiovascular disease, identification of patients at risk for cardiovascular events and treatment stratification is needed. The predictive power of classical risk factors is limited, especially in patients with manifest atherosclerosis. Imaging modalities have focused on the characteristics of the vulnerable plaque. However, it has become evident that not all so-called vulnerable plaques lead to rupture and subsequent thrombosis. The latter obviously limits the positive predictive value for imaging assessment of plaques and patients at risk. Serum biomarkers have also been studied extensively, but have very limited application in a clinical setting for risk stratification. In line with the important relation between vulnerable plaques and cardiovascular events, plaque biomarker studies have been initiated. These longitudinal studies are based on the concept, that a vulnerable plaque contains predictive information for future cardiovascular events, also in other territories of the vascular tree. Results look promising and plaque markers can be used to develop imaging modalities to identify patients at risk, or to monitor treatment effect. Plaque biomarker studies do not challenge the definition of the vulnerable plaque, but use its concept in favor of prediction improvement for vascular patients.     

Imaging of high-risk plaque

'High-risk' or 'vulnerable' plaques in the coronary arteries have characteristics that make them more prone to disruption and subsequent thrombosis -- the mechanisms of most acute coronary syndromes (ACS). There are a number of imaging modalities that are capable of visualizing these features. This article discusses invasive modalities for identifying 'high-risk' plaque such as intravascular ultrasound, coronary angioscopy, optical coherence tomography, near-infrared spectroscopy and coronary thermography. It also discusses the use of noninvasive modalities such as computed tomography MRI and ultrasound. When these imaging modalities are combined with standard cardiac risk factors and more novel markers of systemic inflammation and thrombogenicity we can improve our ability to identify the 'high-risk' patient.     

急性冠状动脉综合征患者孤立性和弥漫性斑块的临床研究

目的探讨急性冠状动脉综合征患者冠状动脉孤立性病变和弥漫性病变的不同临床特征。方法从1900例冠状动脉CT检查中连续选择明确诊断急性冠状动脉综合征的患者95例,根据CT结果将患者冠状动脉病变分为孤立性病变(孤立组,61例)和弥漫性病变(弥漫组,34例),比较2组临床特征、CT积分和预后情况。结果与孤立组比较,弥漫组患者年龄更大,高血压、糖尿病、外周血管病、陈旧性心肌梗死、心功能不全的比例更高(P0.05,P0.01);弥漫组患者冠状动脉狭窄积分、病变节段积分、3支病变积分、左主干病变积分、钙化积分均明显增高(P0.05,P0.01)。随访期间,弥漫组患者心血管事件发生率明显高于孤立组(P0.05)。结论以孤立性病变和弥漫性病变区分急性冠状动脉综合征患者可作为临床判定病情和评估治疗效果的参考。