Although mortality rates from coronary heart disease in the western countries have declined in the last few decades, morbidity caused by this disease is increasing and a substantial number of ...patients still suffer acute coronary syndrome (ACS) and sudden cardiac death. Acute coronary syndrome occurs as a result of myocardial ischaemia and its manifestations include acute myocardial infarction and unstable angina. Culprit plaque morphology in these patients varies from thrombosis with or without coronary occlusion to sudden narrowing of the lumen from intraplaque haemorrhage. The coronary artery plaque morphologies primarily responsible for thrombosis are plaque rupture, and plaque erosion, with plaque rupture being the most common cause of acute myocardial infarction, especially in men. Autopsy data demonstrate that women <50 years of age more frequently have erosion, whereas in older women, the frequency of rupture increases with each decade. Ruptured plaques are associated with positive (expansive) remodelling and characterized by a large necrotic core and a thin fibrous cap that is disrupted and infiltrated by foamy macrophages. Plaque erosion lesions are often negatively remodelled with the plaque itself being rich in smooth muscle cells and proteoglycans with minimal to absence of inflammation. Plaque haemorrhage may expand the plaque rapidly, leading to the development of unstable angina. Plaque haemorrhage may occur from plaque rupture (fissure) or from neovascularization (angiogenesis). Atherosclerosis is now recognized as an inflammatory disease with macrophages and T-lymphocytes playing a dominant role. Recently at least two subtypes of macrophages have been identified. M1 is a pro-inflammatory macrophage while M2 seems to play a role in dampening inflammation and promoting tissue repair. A third type of macrophage, termed by us as haemoglobin associated macrophage or M(Hb) which is observed at site of haemorrhage also can be demonstrated in human atherosclerosis. In order to further our understanding of the specific biological events which trigger plaque instability and as well as to monitor the effects of novel anti-atherosclerotic therapies newer imaging modalities in vivo are needed.
Animal studies are a foundation for defining mechanisms of atherosclerosis and potential targets of drugs to prevent lesion development or reverse the disease. In the current literature, it is common ...to see contradictions of outcomes in animal studies from different research groups, leading to the paucity of extrapolations of experimental findings into understanding the human disease. The purpose of this statement is to provide guidelines for development and execution of experimental design and interpretation in animal studies. Recommendations include the following: (1) animal model selection, with commentary on the fidelity of mimicking facets of the human disease; (2) experimental design and its impact on the interpretation of data; and (3) standard methods to enhance accuracy of measurements and characterization of atherosclerotic lesions.
Animal studies are a foundation for defining mechanisms of atherosclerosis and potential targets of drugs to prevent lesion development or reverse the disease. In the current literature, it is common ...to see contradictions of outcomes in animal studies from different research groups, leading to the paucity of extrapolations of experimental findings into understanding the human disease. The purpose of this statement is to provide guidelines for development and execution of experimental design and interpretation in animal studies. Recommendations include the following: (1) animal model selection, with commentary on the fidelity of mimicking facets of the human disease; (2) experimental design and its impact on the interpretation of data; and (3) standard methods to enhance accuracy of measurements and characterization of atherosclerotic lesions.
This article has been retracted: please see Elsevier Policy on Article Withdrawal ( http://www.elsevier.com/locate/withdrawalpolicy ). This article has been retracted at the request of the ...Editor-in-Chief. We cannot confirm the identity of this author after an inquiry from a reader. We contacted the author directly but did not receive a response.
In terms of pathology, the late stage of AAA is characterized by accumulation of proteolytic enzymes and loss of extracellular matrix and vascular smooth muscle cells in media, angiogenesis and ...chronic inflammation dominated by mononuclear cells in media and adventitia, atherosclerotic changes in intima, and unorganized laminated thrombus in the aneurysm sac (15). ...is the apoB-based vaccine safe?
The identification of asymptomatic individuals at risk for near-term atherothrombotic events to ensure optimal preventive treatment remains a challenging goal. In the BioImage Study, novel approaches ...are tested in a typical health-plan population. Based on certain demographic and risk characteristics on file with Humana Inc, a total of 7,687 men 55 to 80 years of age and women 60 to 80 years of age without evidence of atherothrombotic disease but presumed to be at risk for near-term atherothrombotic events were enrolled between January 2008 and June 2009. Those who met the prespecified eligibility criteria were randomized to a telephonic health survey only (survey only: n = 865), standard risk assessment (Framingham only: n = 718), or comprehensive risk assessment in a dedicated mobile facility equipped with advanced imaging tools (n = 6,104). Baseline examination included assessment of cardiovascular risk factors and screening for subclinical (asymptomatic) atherosclerosis with quantification of coronary artery calcification by computed tomography (CT), measurement of intima-media thickness, presence of carotid atherosclerotic plaques and abdominal aortic aneurysm by ultrasound, and ankle brachial index. Participants with one or more abnormal screening test results underwent advanced imaging with contrast-enhanced magnetic resonance imaging for carotid and aortic plaques, contrast-enhanced coronary CT angiography for luminal stenosis and noncalcified plaques, and 18F-fluorodeoxyglucose–positron emission tomography/CT for carotid and aortic plaque inflammation. Plasma, PAXgene RNA, and DNA samples were obtained, frozen, and stored for future biomarker discovery studies. All individuals will be followed until 600 major atherothrombotic events have occurred in those undergoing imaging. The BioImage Study will help identify those patients with subclinical atherosclerosis who are at risk for near-term atherothrombotic events and enable a more personalized management of care.
Pathogenesis of Atherosclerosis Falk, Erling
Journal of the American College of Cardiology,
04/2006, Letnik:
47, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Pathogenesis of Atherosclerosis
Erling Falk
Atherosclerosis is a multifocal, smoldering, immunoinflammatory disease of medium-sized and large arteries fuelled by lipid. The most devastating ...consequences of atherosclerosis, such as heart attack and stroke, are caused by superimposed thrombosis. Approximately 76% of all fatal coronary thrombi are precipitated by plaque rupture. Ruptured plaques are characterized by a large lipid-rich core, a thin fibrous cap that contains few smooth muscle cells and many macrophages, angiogenesis, adventitial inflammation, and outward remodeling. Thus, ruptured plaques and, by inference, rupture-prone plaques have characteristic pathoanatomical features that might be useful for their detection in vivo by imaging.
Atherosclerosis is a multifocal, smoldering, immunoinflammatory disease of medium-sized and large arteries fuelled by lipids. Endothelial cells, leukocytes, and intimal smooth muscle cells are the major players in the development of this disease. The most devastating consequences of atherosclerosis, such as heart attack and stroke, are caused by superimposed thrombosis. Therefore, the vital question is not why atherosclerosis develops but rather why atherosclerosis, after years of indolent growth, suddenly becomes complicated with luminal thrombosis. If thrombosis-prone plaques could be detected and thrombosis averted, atherosclerosis would be a much more benign disease. Approximately 76% of all fatal coronary thrombi are precipitated by plaque rupture. Plaque rupture is a more frequent cause of coronary thrombosis in men (∼80%) than in women (∼60%). Ruptured plaques are characterized by a large lipid-rich core, a thin fibrous cap that contains few smooth muscle cells and many macrophages, angiogenesis, adventitial inflammation, and outward remodeling. Plaque rupture is the most common cause of coronary thrombosis. Ruptured plaques and, by inference, rupture-prone plaques have characteristic pathoanatomical features that might be useful for their detection in vivo by imaging. This article describes the pathogenesis of atherosclerosis, how it begets thrombosis, and the possibility to detect thrombosis-prone plaques and prevent heart attack.
Plaque rupture in humans and mice Schwartz, Stephen M; Galis, Zorina S; Rosenfeld, Michael E ...
Arteriosclerosis, thrombosis, and vascular biology,
2007-April, Letnik:
27, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Despite the many studies of murine atherosclerosis, we do not yet know the relevance of the natural history of this model to the final events precipitated by plaque disruption of human ...atherosclerotic lesions. The literature has become particularly confused because of the common use of terms such as "instability", "vulnerable", "rupture", or even "thrombosis" for features of plaques in murine model systems not yet shown to rupture spontaneously and in an animal surprisingly resistant to formation of thrombi at sites of atherosclerosis. We suggest that use of conclusory terms like "vulnerable" and "stable" should be discouraged. Similarly, terms such as "buried fibrous caps" that imply preceding events that are unproven tend to create confusion. We will argue that such terminology may mislead readers by implying knowledge that does not yet exist. We suggest, instead, a focus on specific processes that various forms of data have implicated in plaque progression. For example, formation of the fibrous cap, protease activation, and cell death in the necrotic core can be well described and have all been modeled in well-defined experiments. The relevance of such well-defined, objective, descriptive observations in the mouse can be tested for relevance against data from human pathology.
Intravascular ultrasound-derived virtual histology (VH IVUS) is used increasingly in clinical research to assess composition and vulnerability of coronary atherosclerotic lesions. However, the ...ability of VH IVUS to quantify individual plaque components, in particular the size of the destabilizing necrotic core, has never been validated. We tested for correlation between VH IVUS necrotic core size and necrotic core size by histology in porcine coronary arteries with human-like coronary disease.
In adult atherosclerosis-prone minipigs, 18 advanced coronary lesions were assessed by VH IVUS in vivo followed by postmortem microscopic examination (histology). We found no correlation between the size of the necrotic core determined by VH IVUS and histology. VH IVUS displayed necrotic cores in lesions lacking cores by histology.
We found no correlation between necrotic core size determined by VH IVUS and real histology, questioning the ability of VH IVUS to detect rupture-prone plaques, so-called thin-cap fibroatheromas.
Statin Therapy on the Basis of HOPE Falk, Erling, MD, DMSc; Mortensen, Martin Bødtker, MD, PhD
Journal of the American College of Cardiology,
12/2016, Letnik:
68, Številka:
25
Journal Article
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