Morphology of the endothelium over atherosclerotic plaques in human coronary arteries.

The right coronary arteries of six hearts removed from patients with atherosclerosis, who were undergoing cardiac transplantation, were perfused with 2% buffered glutaraldehyde for 20 minutes before preparation for scanning electron microscopy. Perfusion was started within five minutes of explanation. In two patients the artery was angiographically normal, in one it was irregular in outline, and three had focal segments with significant stenosis. None of the patients had concentrations of plasma lipids above 5.5 mmol/l. The endothelial surface showed widespread focal abnormalities ranging from adhesion and migration of monocytes to loss of individual endothelial cells. Larger areas of endothelial denudation with exposure of underlying collagen were also seen consistently. Loss of endothelial cells was associated with accumulation of monocytes, on and deep to the surface, as well as adhesion of platelets to the exposed subendothelial tissue. These results accord with the endothelial damage and platelet adhesion seen in hyperlipidaemic animals fed a high lipid diet.     

Morphology of the endothelium over atherosclerotic plaques in human coronary arteries

The right coronary arteries of six hearts removed from patients with atherosclerosis, who were undergoing cardiac transplantation, were perfused with 2% buffered glutaraldehyde for 20 minutes before preparation for scanning electron microscopy. Perfusion was started within five minutes of explanation. In two patients the artery was angiographically normal, in one it was irregular in outline, and three had focal segments with significant stenosis. None of the patients had concentrations of plasma lipids above 5.5 mmol/l. The endothelial surface showed widespread focal abnormalities ranging from adhesion and migration of monocytes to loss of individual endothelial cells. Larger areas of endothelial denudation with exposure of underlying collagen were also seen consistently. Loss of endothelial cells was associated with accumulation of monocytes, on and deep to the surface, as well as adhesion of platelets to the exposed subendothelial tissue. These results accord with the endothelial damage and platelet adhesion seen in hyperlipidaemic animals fed a high lipid diet.     

Intravascular ultrasound imaging of ruptured atherosclerotic plaques in coronary arteries

Intravascular ultrasound demonstrated plaque ruptures that occurred in regions involved with large complicated atherosclerotic plaques in the coronary artery. Because intravascular ultrasound evaluates both plaque and luminal dimensions, it contributes to our understanding of the pathophysiology of coronary artery disease.     

The localization of sudanophilic and fibrous plaques in the main left coronary bifurcation

We have studied the localization of early sudanophilic and fibrous plaques in the main stem and proximal branches of opened and stained left coronary arteries. The distribution of lesions was separately assessed by a computer technique. The early sudanophilic lesions develop in the proximal portion of the coronary artery branches and subsequent lesions spread distally and appear first and most prominently in the left anterior descending branch. Around the bifurcation both sudanophilic and fibrous plaques had a distinct spatial distribution with peak incidence on the outer walls. In contrast, the flow divider and the inner walls downstream from it were relatively free of disease.     

血清学指标对不稳定斑块的诊断价值

目的以血管内超声-虚拟组织学（intravascularunltrasound-virtualhistology，IVUS-VH）分析为参照，观察血清学指标对不稳定斑块的预测意义。方法纳入69例冠状动脉粥样硬化性心脏病（冠心病）患者，于人院后检测各项血清学指标后，行冠状动脉造影及IVUS-vH分析斑块性质，通过受试者工作曲线（ROC）分析各项指标对不稳定斑块的诊断意义以及联合检测血清学指标对不稳定斑块的诊断符合率。结果心脏型脂肪酸结合蛋白（heart-typefattyacid-bindingprotein，HFAP）、超敏C反应蛋白（high-sensitivityC-reactiveprotein，hs-CRP）、肌钙蛋白（cardiactroponin，cTnI）受试者工作曲线下面积分别为0．833、0．692、0．647，P均〈0．05。HFAP、hs-CRP、cTnI联合检测对不稳定斑块诊断的符合率为93．75％；HFAP及hs-CRP联合检测对不稳定斑块诊断的符合率为63．16％；hs-CRP及cTnI联合检测对不稳定斑块诊断的符合率64．52％；HFAP及cTnI联合检测对不稳定斑块诊断的符合率为66．67％。结论对不稳定斑块诊断，单项检测时HFAP最优，其次为cTnI，最后为hs-CRP；HFAP、cTnI、hs-CRP三者联合检测优于任意两者联合。     

Molecular imaging of plaques in coronary arteries with PET and SPECT

Coronary artery disease remains a major cause of mortality. Presence of atherosclerotic plaques in the coronary artery is responsible for lu-men stenosis which is often used as an indicator for determining the severity of coronary artery disease. However, the degree of coronary lumen stenosis is not often related to compromising myocardial blood flow, as most of the cardiac events that are caused by atherosclerotic plaques are the result of vulnerable plaques which are prone to rupture. Thus, identification of vulnerable plaques in coronary arteries has become increas-ingly important to assist identify patients with high cardiovascular risks. Molecular imaging with use of positron emission tomography （PET） and single photon emission computed tomography （SPECT） has fulfilled this goal by providing functional information about plaque activity which enables accurate assessment of plaque stability. This review article provides an overview of diagnostic applications of molecular imaging tech-niques in the detection of plaques in coronary arteries with PET and SPECT. New radiopharmaceuticals used in the molecular imaging of coro-nary plaques and diagnostic applications of integrated PET/CT and PET/MRI in coronary plaques are also discussed.     

Quantitative morphologic studies for localizing arteriosclerotic plaques in the circumference of coronary arteries

In order to determine the distribution of arteriosclerotic plaques in the circumference of coronary arteries 150 hearts were investigated using two different methods. In 100 hearts the coronary vessels were opened longitudinally, and the sites of sclerotic lesions were mapped. The coronary arteries of another 50 hearts were filled with contrast medium, angiography was performed and the arteries were cut into 0.5-cm segments. The first 6 cm of the left anterior descending and the left circumflex arteries and the first 9 cm of the right coronary artery were studied. Segments of 1-cm length in the 100 hearts and of 0.5-cm length in the 50 hearts were examined. It was found, that arteriosclerotic lesions of the coronary arteries are most frequently located on the myocardial side of the vessel circumference. This phenomenon is most evident in the left anterior descending artery, thus possibly being caused by the most pronounced fixation of this artery on the myocardium.     

Composition of atherosclerotic plaques in the epicardial coronary arteries in juvenile (type I) diabetes mellitus.

The composition of atherosclerotic plaques in 331 five-mm segments of the 4 major (left main, left anterior descending, left circumflex, and right) epicardial coronary arteries of 8 patients with juvenile (mean age at onset, 9 years; mean age at death, 29 years) diabetes mellitus was determined by computerized planimetric analysis. Analysis of all coronary segments disclosed that the plaques consisted primarily of dense (53%) and cellular (38%) fibrous tissue. Pultaceous debris (7%), foam cells (1.2%) and calcific deposits (0.7%) occupied a small percentage of the plaques. Thus, 91% of the coronary plaques in these young diabetic patients consisted of fibrous tissue and nearly all of the remaining 9% consisted of lipid deposits. Analysis of composition according to degrees of cross-sectional luminal narrowing revealed marked increases in dense fibrous tissue (from 31 to 74%), pultaceous debris (from 3 to 12%), and calcific deposits (from 0% to 3%) as the cross-sectional area narrowing increased from < or = 25% to > 75%. Compared with older patients with fatal coronary artery disease, the patients with juvenile diabetes had more dense fibrous tissue and pultaceous debris and less calcific deposits.     

Revised microcalcification hypothesis for fibrous cap rupture in human coronary arteries

Using 2.1-µm high-resolution microcomputed tomography, we have examined the spatial distribution, clustering, and shape of nearly 35,000 microcalcifications (µCalcs) ≥ 5 µm in the fibrous caps of 22 nonruptured human atherosclerotic plaques. The vast majority of these µCalcs were <15 µm and invisible at the previously used 6.7-µm resolution. A greatly simplified 3D finite element analysis has made it possible to quickly analyze which of these thousands of minute inclusions are potentially dangerous. We show that the enhancement of the local tissue stress caused by particle clustering increases rapidly for gap between particle pairs (h)/particle diameter (D) < 0.4 if particles are oriented along the tensile axis of the cap. Of the thousands of µCalcs observed, there were 193 particle pairs with h/D ≤ 2 (tissue stress factor > 2), but only 3 of these pairs had h/D ≤ 0.4, where the local tissue stress could increase a factor > 5. Using nondecalcified histology, we also show that nearly all caps have µCalcs between 0.5 and 5 µm and that the µCalcs ≥ 5 µm observed in high-resolution microcomputed tomography are agglomerations of smaller calcified matrix vesicles. µCalcs < 5 µm are predicted to be not harmful, because the tiny voids associated with these very small particles will not explosively grow under tensile forces because of their large surface energy. These observations strongly support the hypothesis that nearly all fibrous caps have µCalcs, but only a small subset has the potential for rupture.     

Multiple ruptures of atherosclerotic plaques in acute coronary syndrome. Endocoronary ultrasonography study of three arteries

The aim of this study was to assess the three coronary arteries systematically by endocoronary ultrasonography in patients with unstable angina to check the hypothesis of global destabilisation of atherosclerotic plaques in acute coronary syndromes (ACS). Sixty two coronary arteries were examined (2.6 per patient). Fifty plaque ruptures were diagnosed (2.08 per patient). Rupture of a plaque of the culprit lesion of the ACS was clearly detected in 9 patients (37.5%). At least one ruptured plaque on a site other than the culprit lesion was observed in 19 patients (79%), on another artery in 70.8% of cases and on two other arteries in 12.5% of cases. A complete endocoronary ultrasonic examination of the three coronary arteries in patients with a first ACS demonstrated that: multiple atherosclerotic plaque rupture may be detected by endocoronary ultrasonography; these multiple plaque ruptures occur simultaneously with the culprit lesion; they are frequent and can be situated on the three main coronary vessels and multiple plaque rupture other than the culprit lesion are less severe, non stenotic and less calcified. Thus, although a single lesion is clinically symptomatic, ACS seems to be associated with global coronary instability.     

Comparison of composition of atherosclerotic plaques in saphenous veins used as aortocoronary bypass conduits with plaques in native coronary arteries in the same men.

This study describes quantitatively the components of atherosclerotic plaques in saphenous vein grafts used for aortocoronary bypass and compares the findings with the plaques in the native coronary arteries in the same men. A total of 607 five-mm segments of saphenous veins and 797 five-mm segments of native coronary arteries were examined by computerized planimetric technique in 19 men, aged 39 to 82 years (mean 61), who had survived bypass operation for > 1 year. Comparison of the mean percentages of the plaque components in saphenous vein grafts in place for 14 to 26 months with those of the native coronary arteries revealed significant differences: cellular fibrous tissue, 86 vs 7%; dense fibrous tissue, 13 vs 82%; p < 0.05. As survival time after the bypass operation increased, composition of the plaques in the saphenous veins changed so that by approximately 80 months the amounts of cellular and dense fibrous tissue in both saphenous vein grafts and native coronary arteries were similar: 10 vs 16%, and 75 vs 71%; p = not significant. Thus, by about 7 years after a coronary bypass operation the composition of plaques in saphenous vein grafts is similar to that in the native coronary arteries of the same patients.     

Studies on the distribution of lipids within fibrous plaques.

The present report is an attempt to determine the nature of the circulation of lipids within fibrous plaques by studying the pattern of lipid distribution within the plaques. The material was obtained from aortas from 405 mammals and birds dying in the Oklahoma City Zoo. Analysis of the pattern of lipid distribution in 187 lipid containing aortic fibrous plaques suggested that most of the lipids entered the plaques at the shoulders and circulated from there toward the centers, usually in the outermost layers of the plaques.     

Infection-associated intimal thickening in the coronary arteries of children

OBJECTIVES: based on autopsy material from children this study investigated the possible relationship of clinically evident infection prior to death with intimal thickening of the coronary arteries. BACKGROUND: viral infections are suggested to be associated with intimal thickening in the coronary arteries both in animals and man. METHODS: the coronary arteries were examined in 175 autopsied children 0-15 years of age (median 7 days). Semi-serial cross sections of the coronary arteries were screened for maximal intimal thickening at 0.2 mm intervals. The length of the internal elastic lamina, the areas of arterial media and intima were measured from cross-sections. Irregular linings of the arteries were mathematically transformed to circles. The percentage of intimal and musculoelastic layer area to luminal area encircled by arterial media was calculated. RESULTS: intimal thickening increased with age but was also associated with the presence of infectious disease at death. Already in the newborn children, who died shortly after the birth, the percentage of intimal and musculoelastic layer area to luminal area encircled by arterial media was big, maximally 55%. In the left coronary artery the mean percentages were 32 and 21% in the groups with viral and bacterial infections, respectively as compared to 16% in the group with no evidence of infection. CONCLUSION: infections in general and viral infections in particular, seem to be associated with intimal thickening, which may predispose coronary arteries to atherosclerosis. Atherogenesis might have a rapid dynamic component.     

Evaluation by multislice computed tomography of atherosclerotic coronary artery plaques in non-culprit, remote coronary arteries of patients with acute coronary syndrome.

BACKGROUND: Patients with acute coronary syndrome (ACS) frequently have vulnerable plaques in the remote coronary arteries, suggesting that ACS is part of the pan-coronary process. In the present study the computed tomography (CT) plaque density in non-culprit atherosclerotic coronary artery lesions was evaluated by multislice computed tomography (MSCT) in patients with ACS and non-ACS. METHODS AND RESULTS: MSCT was performed in 21 patients with ACS and 53 patients with non-ACS: 16 of the 21 ACS patients (76%) and 30 of the non-ACS 53 patients (57 %) had non-calcified plaques in the non-culprit coronary arteries (p=0.18). CT-low-density plaques (CT density <68 Hounsfield units (HU)) were more frequent in the ACS group (13/16 patients, 81%) than in the non-ACS group (13/30 patients, 43%, p=0.03). In addition, the CT density of the non-culprit lesion was significantly lower in patients with ACS than in those with non-ACS (44.1+/-22.9 and 77.3+/-33.7 HU, respectively). CONCLUSION: Patients with ACS more frequently had CT-low-density plaques in the non-culprit, remote arteries than those with non-ACS, which suggests that ACS treatment should focus not only on stabilizing the culprit lesion but also on systemic stabilization of non-culprit lesions.     

Frequency and distribution of thin-cap fibroatheroma and ruptured plaques in human coronary arteries: a pathologic study.

OBJECTIVES: Our purpose was to quantify the frequency and distribution of suspected vulnerable lesions, defined as thin-capped fibroatheroma (TCFA) and ruptured plaque, in human coronary artery autopsy specimens. BACKGROUND: Most acute coronary events and sudden death are believed to arise from rupture of a TCFA followed by thrombosis. Although there is general agreement that clinical events are usually caused by focal lesions, there is considerable debate over the relative importance of focal versus systemic factors in the pathogenesis of atherosclerosis. METHODS: We longitudinally sectioned coronary arteries from 50 whole hearts taken from patients (mean age 73 years, 64% men) dying of cardiovascular (n = 33), noncardiovascular (n = 13), and unknown (n = 4) causes. A total of 3,639 longitudinal segments of length 3 mm were sectioned from 148 arteries, accounting for 10.9 m of total tissue length. Specimens were classified on the basis of histology and computer-aided morphometry. RESULTS: Twenty-three TCFA and 19 ruptured plaques were found (mean +/- SD: 0.46 +/- 0.95 and 0.38 +/- 0.70 per heart, respectively), and these lesions accounted for only 1.6% and 1.2%, respectively, of the total length of the coronary tree examined in patients dying of cardiovascular causes. The majority of TCFA and ruptured plaque localized in the proximal third of the major coronary arteries, and in 92% of cases these lesions clustered within 2 or fewer nonoverlapping 20-mm segments. CONCLUSIONS: The suspected precursors of rupture-mediated thrombosis occur in a limited, focal distribution in the coronary arteries.     

Echolucent carotid plaques predict in-stent restenosis after bare metal stenting in native coronary arteries

Echolucent carotid plaque is considered to predict coronary events. This study examined whether echolucent carotid plaque may predict in-stent restenosis (ISR) in coronary arteries. This study included 202 patients who had elective and successful percutaneous coronary intervention (PCI) with bare metal stents in de novo lesions of native coronary arteries for symptomatic coronary artery disease (CAD). Carotid plaque echolucency was assessed by ultrasound with integrated backscatter (IBS) analysis (intima-media IBS value minus adventitia IBS) 1 day before PCI. All patients underwent planned coronary angiography (CAG) at 6 months after PCI, or CAG before 6 months due to acute coronary syndromes. ISR (defined as >50% diameter stenosis) was found in 65 (32%) patients. The calibrated IBS values of carotid plaques were inversely correlated with late luminal loss of the stented lesions. Using multivariate logistic regression analysis, the presence of echolucent carotid plaques (相似文献