Plaque In Acute Coronary Syndrome Research Articles

Multislice Computed Tomographic Characteristics of Coronary Lesions in Acute Coronary Syndromes

To evaluate the feasibility of noninvasive assessment of the characteristics of disrupted atherosclerotic plaques, the authors interrogated the culprit lesions in acute coronary syndromes (ACS) by multislice computed tomography (CT). Disrupted atherosclerotic plaques responsible for ACS histopathologically demonstrate large lipid cores and positive vascular remodeling. It is expected that plaques vulnerable to rupture should bear similar imaging signatures by CT. Either 0.5-mm x 16-slice or 64-slice CT was performed in 38 patients with ACS and compared with 33 patients with stable angina pectoris (SAP) before percutaneous coronary intervention. The coronary plaques in ACS and SAP were evaluated for the CT plaque characteristics, including vessel remodeling, consistency of noncalcified plaque (NCP <30 HU or 30 HU <NCP <150 HU), and spotty or large calcification. In the CT profile of culprit ACS and SAP lesions, the frequency of 30 HU <NCP <150 HU (100% vs. 100%, p = NS) was not different, and large calcification (22% vs. 55%, p = 0.004) was significantly more frequent in the stable lesions. Positive remodeling (87% vs. 12%, p < 0.0001), NCP <30 HU (79% vs. 9%, p < 0.0001), and spotty calcification (63% vs. 21%, p = 0.0005) were significantly more frequent in the ACS lesions. Presence of all 3 (i.e., positive remodeling, NCP <30 HU, and spotty calcification) showed a high positive predictive value, and absence of all 3 showed a high negative predictive value for the culprit plaques associated with ACS. The CT characteristics of plaques associated with ACS include positive vascular remodeling, low plaque density, and spotty calcification. It is logical to presume that plaques vulnerable to rupture harbor similar characteristics.

Presence and Severity of Chlamydia pneumoniae and Cytomegalovirus Infection in Coronary Plaques Are Associated With Acute Coronary Syndromes

Although an association between Chlamydia pneumoniae (Cpn) or Cytomegalovirus (CMV) infection and coronary atherosclerosis has been reported, such an association is less clear for acute coronary syndromes (ACS). The purpose of this study was to investigate the pathogenic roles of Cpn and CMV infection of coronary plaques in ACS. We divided 38 coronary plaque specimens obtained from 38 patients who underwent directional coronary atherectomy or thrombectomy into an ACS group (n = 21) and a non-ACS group (n = 17). Cpn and CMV in specimens were stained using immunohistochemical techniques and analyzed quantitatively. The detection rate for either Cpn- or CMV-positive cells in ACS patients was slightly higher compared with non-ACS patients. Detection rates for both Cpn- and CMV-positive cells were significantly higher in ACS patients than in non-ACS patients (P = 0.010). Furthermore, the density of Cpn- and CMV-positive cells in plaques was significantly higher in ACS patients than in non-ACS patients (P < 0.003). The results indicate that the presence and severity of Cpn and CMV infection in coronary plaques are greater in patients with ACS compared with non-ACS patients. We conclude that infection with Cpn and CMV in coronary plaques may be involved in the pathogenesis of ACS.

826-2 Interleukin-6 but not C-reactive protein is elevated at the site of ruptured plaques in acute coronary syndromes

826-2 Interleukin-6 but not C-reactive protein is elevated at the site of ruptured plaques in acute coronary syndromes

Clinical implications of carotid artery remodeling in acute coronary syndrome: Ultrasonographic assessment of positive remodeling

ObjectivesWe investigated the relationship between ultrasonographic features of the carotid artery and the angiographic features of coronary plaques in acute coronary syndrome (ACS). BackgroundThe carotid intima-media thickness (IMT) may be a marker of advanced coronary artery disease. MethodsConsecutive ACS patients (N = 125) underwent B-mode ultrasonography within one week of the acute coronary event. Using a 7.5-MHz linear array transducer, the common carotid IMT, interadventitial diameter, and luminal diameter were examined. Carotid plaques were also assessed. Then patients were divided into two groups based on the number of complex plaques identified by coronary angiography. ResultsThe carotid IMT of 75 patients with multiple complex coronary plaques was significantly larger than that of 50 patients with solitary plaques (p < 0.0003). The prevalence of soft and hard carotid plaques was higher in the group with multiple coronary plaques than in those with single plaques (28% vs. 12%, p < 0.04 and 13% vs. 0%, p < 0.008, respectively). Additionally, the carotid interadventitial diameter was larger in the patients with multiple plaques than in those with single plaques (7.93 ± 0.97 mm vs. 7.48 ± 0.88 mm, p < 0.01), and a significant correlation was observed between the carotid IMT and interadventitial diameter (R = 0.54, p < 0.0001). ConclusionsIn ACS, multiple complex coronary plaques are associated with positive carotid remodeling, suggesting that plaque vulnerability may be a systemic phenomenon.

Emerging importance of HDL cholesterol in developing high-risk coronary plaques in acute coronary syndromes

Cardiovascular disease is the principal cause of death in industrialized countries. Hyperlipidemia, with high low-density lipoprotein cholesterol and triglycerides, and low high-density lipoprotein cholesterol levels (<40 mg/dL in men and <45 mg/dL in women), is a known major cardiovascular risk factor. Statins are considered the most potent and effective agents to reduce low-density lipoprotein cholesterol, but they have a variable effect on high-density lipoprotein cholesterol and triglycerides. Different clinical trials with statins have shown a decrease in low-density lipoprotein cholesterol by 35% and a reduction of the incidence of coronary events by as much as 30%. However, 60 to 70% of events still occur, despite remarkable reduction of low-density lipoprotein cholesterol concentration. Recent National Cholesterol Education Program guidelines highlighted the importance of high-density lipoprotein cholesterol concentration in the prevention and treatment of cardiovascular disease. High-density lipoprotein cholesterol is considered an independent risk factor and has an inverse relation with coronary events. The association of low levels of high-density lipoprotein cholesterol with an increased incidence of cardiovascular events implies a critical role of high-density lipoprotein in the protection against atherosclerotic disease and in the progression of coronary atherosclerotic disease. High-density lipoprotein cholesterol appears to exert this protective effect through multiple mechanisms. High-density lipoprotein is not only involved in reverse cholesterol transport, but also prevents endothelial dysfunction; inhibits the homing of monocytes, apoptosis, platelet activation, and factor X activation; and has antioxidant properties. In this article the authors review the available experimental and clinical evidence supporting the importance of high-density lipoprotein cholesterol as a protective factor in coronary artery disease, and the strategies developed to increase high-density lipoprotein cholesterol.

Angiographic Differences Analysis of Coronary Artery Lesions in Patients with Stable and Unstable Angina Pectoris

Background and Objectives:As previously reported, unstable angina is usually related to characteristic cor- onary artery lesion's morphology analyzed by coronary angiogram. This takes the form of an eccentrically placed convex stenosis with a narrow neck due to one or more overhanging edges or irregular, scalloped borders, or both. Although most studies were done for lesions with high degree stenosis (>50%, recent studies emphas- ized the role of vulnerability of plaque in acute coronary syndrome and even mild degree stenotic lesions may progress rapidly to evoke acute coronary syndrome. Therefore in this study, we analyzed the morphological characteristics of coronary artery lesions with mild degree stenosis as well as severe stenosis. Materials and Methods:We conducted a retrospective study of 96 patients with angina pectoris (42 of stable patients and 54 of unstable patients who underwent coronary angiography. Each lesions with 25% or greater diameter ste- nosis were categorized into simple and complex lesion (convex intraluminal obstruction with a narrow neck or irregular borders, diffuse irregularities, ulceration, thrombus. Calcification of coronary artery, extents of lesions were analyzed and stenosis grade and location were categorized by AHA classification. Results:There were no significant differences between the stable angina and unstable angina in risk factors and vessel involvement, numbers of lesions, calcification and total obstruction. In morphologic analysis, complex lesions were more frequent in unstable angina than stable angina (49% vs 33%, p<0.05. The mean of percent diameter stenosis was not significantly different between two groups, but severe stenotic lesions with 90% or more stenosis were more frequent in unstable angina (34% vs 22%, p<0.05. Locations of involved vessels were similar between the angina groups. Complex lesions were distributed more frequent in RCA and simple lesions were more in LAD and LCX (p<0.05. Conclusions:The lesions with both complex morphology and severe degree stenosis are closely implicated in unstable angina. (Korean Circulation J 2000;30(9 :1099-1106