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Journal of Internal Medicine Dec 2014Atherosclerosis is a silent chronic vascular pathology that is the cause of the majority of cardiovascular ischaemic events. The evolution of vascular disease involves a... (Review)
Review
Atherosclerosis is a silent chronic vascular pathology that is the cause of the majority of cardiovascular ischaemic events. The evolution of vascular disease involves a combination of endothelial dysfunction, extensive lipid deposition in the intima, exacerbated innate and adaptive immune responses, proliferation of vascular smooth muscle cells and remodelling of the extracellular matrix, resulting in the formation of an atherosclerotic plaque. High-risk plaques have a large acellular lipid-rich necrotic core with an overlying thin fibrous cap infiltrated by inflammatory cells and diffuse calcification. The formation of new fragile and leaky vessels that invade the expanding intima contributes to enlarge the necrotic core increasing the vulnerability of the plaque. In addition, biomechanical, haemodynamic and physical factors contribute to plaque destabilization. Upon erosion or rupture, these high-risk lipid-rich vulnerable plaques expose vascular structures or necrotic core components to the circulation, which causes the activation of tissue factor and the subsequent formation of a fibrin monolayer (coagulation cascade) and, concomitantly, the recruitment of circulating platelets and inflammatory cells. The interaction between exposed atherosclerotic plaque components, platelet receptors and coagulation factors eventually leads to platelet activation, aggregation and the subsequent formation of a superimposed thrombus (i.e. atherothrombosis) which may compromise the arterial lumen leading to the presentation of acute ischaemic syndromes. In this review, we will describe the progression of the atherosclerotic lesion along with the main morphological characteristics that predispose to plaque rupture, and discuss the multifaceted mechanisms that drive platelet activation and subsequent thrombus formation. Finally, we will consider the current scientific challenges and future research directions.
Topics: Atherosclerosis; Blood Coagulation; Endothelium, Vascular; Fibrinolysis; Humans; Necrosis; Plaque, Atherosclerotic; Rupture, Spontaneous; Thrombosis
PubMed: 25156650
DOI: 10.1111/joim.12296 -
European Journal of Pharmacology Dec 2017An ideal animal model of atherosclerosis resembles human anatomy and pathophysiology and has the potential to be used in medical and pharmaceutical research to obtain... (Review)
Review
An ideal animal model of atherosclerosis resembles human anatomy and pathophysiology and has the potential to be used in medical and pharmaceutical research to obtain results that can be extrapolated to human medicine. Moreover, it must be easy to acquire, can be maintained at a reasonable cost, is easy to handle and shares the topography of the lesions with humans. In general, animal models of atherosclerosis are based on accelerated plaque formation due to a cholesterol-rich/Western-type diet, manipulation of genes involved in the cholesterol metabolism, and the introduction of additional risk factors for atherosclerosis. Mouse and rabbit models have been mostly used, followed by pigs and non-human primates. Each of these models has its advantages and limitations. The mouse has become the predominant species to study experimental atherosclerosis because of its rapid reproduction, ease of genetic manipulation and its ability to monitor atherogenesis in a reasonable time frame. Both Apolipoprotein E deficient (ApoE) and LDL-receptor (LDLr) knockout mice have been frequently used, but also ApoE/LDLr double-knockout, ApoE3-Leiden and PCSK9-AAV mice are valuable tools in atherosclerosis research. However, a great challenge was the development of a model in which intra-plaque microvessels, haemorrhages, spontaneous atherosclerotic plaque ruptures, myocardial infarction and sudden death occur consistently. These features are present in ApoEFbn1 mice, which can be used as a validated model in pre-clinical studies to evaluate novel plaque-stabilizing drugs.
Topics: Animals; Atherosclerosis; Disease Models, Animal; Plaque, Atherosclerotic
PubMed: 28483459
DOI: 10.1016/j.ejphar.2017.05.010 -
Arteriosclerosis, Thrombosis, and... Jan 2020Macrophages play a central role in the development of atherosclerotic cardiovascular disease (ASCVD), which encompasses coronary artery disease, peripheral artery... (Review)
Review
Macrophages play a central role in the development of atherosclerotic cardiovascular disease (ASCVD), which encompasses coronary artery disease, peripheral artery disease, cerebrovascular disease, and aortic atherosclerosis. In each vascular bed, macrophages contribute to the maintenance of the local inflammatory response, propagate plaque development, and promote thrombosis. These central roles, coupled with their plasticity, makes macrophages attractive therapeutic targets in stemming the development of and stabilizing existing atherosclerosis. In the context of ASCVD, classically activated M1 macrophages initiate and sustain inflammation, and alternatively activated M2 macrophages resolve inflammation. However, this classification is now considered an oversimplification, and a greater understanding of plaque macrophage physiology in ASCVD is required to aid in the development of therapeutics to promote ASCVD regression. Reviewed herein are the macrophage phenotypes and molecular regulators characteristic of ASCVD regression, and the current murine models of ASCVD regression.
Topics: Animals; Atherosclerosis; Coronary Artery Disease; Disease Progression; Humans; Leukocyte Count; Macrophage Activation; Macrophages; Phenotype; Plaque, Atherosclerotic
PubMed: 31722535
DOI: 10.1161/ATVBAHA.119.312802 -
JAMA Cardiology Feb 2023Recent clinical and imaging studies underscore that major adverse cardiac events (MACE) outcomes are associated not solely with severe coronary obstructions (ischemia... (Review)
Review
IMPORTANCE
Recent clinical and imaging studies underscore that major adverse cardiac events (MACE) outcomes are associated not solely with severe coronary obstructions (ischemia hypothesis or stenosis hypothesis), but with the plaque burden along the entire coronary tree. New research clarifies the pathobiologic mechanisms responsible for plaque development/progression/destabilization leading to MACE (plaque hypothesis), but the translation of these insights to clinical management strategies has lagged. This narrative review elaborates the plaque hypothesis and explicates the current understanding of underlying pathobiologic mechanisms, the provocative destabilizing influences, the diagnostic and therapeutic implications, and their actionable clinical management approaches to optimize the management of patients with chronic coronary disease.
OBSERVATIONS
Clinical trials of management strategies for patients with chronic coronary artery disease demonstrate that while MACE rate increases progressively with the anatomic extent of coronary disease, revascularization of the ischemia-producing obstruction does not forestall MACE. Most severely obstructive coronary lesions often remain quiescent and seldom destabilize to cause a MACE. Coronary lesions that later provoke acute myocardial infarction often do not narrow the lumen critically. Invasive and noninvasive imaging can identify the plaque anatomic characteristics (plaque burden, plaque topography, lipid content) and local hemodynamic/biomechanical characteristics (endothelial shear stress, plaque structural stress, axial plaque stress) that can indicate the propensity of individual plaques to provoke a MACE.
CONCLUSIONS AND RELEVANCE
The pathobiologic construct concerning the culprit region of a plaque most likely to cause a MACE (plaque hypothesis), which incorporates multiple convergent plaque features, informs the evolution of a new management strategy capable of identifying the high-risk portion of plaque wherever it is located along the course of the coronary artery. Ongoing investigations of high-risk plaque features, coupled with technical advances to enable prognostic characterization in real time and at the point of care, will soon enable evaluation of the entire length of the atheromatous coronary artery and broaden the target(s) of our therapeutic intervention to include all regions of the plaque (both flow limiting and nonflow limiting).
Topics: Humans; Coronary Artery Disease; Plaque, Atherosclerotic; Myocardial Ischemia; Myocardial Infarction; Risk Factors
PubMed: 36515941
DOI: 10.1001/jamacardio.2022.3926 -
Genes Apr 2022The implication of the heterogeneous spectrum of pro- and anti-inflammatory macrophages (Macs) has been an important area of investigation over the last decade. The... (Review)
Review
The implication of the heterogeneous spectrum of pro- and anti-inflammatory macrophages (Macs) has been an important area of investigation over the last decade. The polarization of Macs alters their functional phenotype in response to their surrounding microenvironment. Macs are the major immune cells implicated in the pathogenesis of atherosclerosis. A hallmark pathology of atherosclerosis is the accumulation of pro-inflammatory M1-like macrophages in coronary arteries induced by pro-atherogenic stimuli; these M1-like pro-inflammatory macrophages are incapable of digesting lipids, thus resulting in foam cell formation in the atherosclerotic plaques. Recent findings suggest that the progression and stability of atherosclerotic plaques are dependent on the quantity of infiltrated Macs, the polarization state of the Macs, and the ratios of different types of Mac populations. The polarization of Macs is defined by signature markers on the cell surface, as well as by factors in intracellular and intranuclear compartments. At the same time, pro- and anti-inflammatory polarized Macs also exhibit different gene expression patterns, with differential cellular characteristics in oxidative phosphorylation and glycolysis. Macs are reflective of different metabolic states and various types of diseases. In this review, we discuss the major differences between M1-like Macs and M2-like Macs, their associated metabolic pathways, and their roles in atherosclerosis.
Topics: Atherosclerosis; Humans; Macrophage Activation; Macrophages; Phenotype; Plaque, Atherosclerotic
PubMed: 35627141
DOI: 10.3390/genes13050756 -
Circulation Apr 2020Physical activity and exercise training are effective strategies for reducing the risk of cardiovascular events, but multiple studies have reported an increased... (Review)
Review
Physical activity and exercise training are effective strategies for reducing the risk of cardiovascular events, but multiple studies have reported an increased prevalence of coronary atherosclerosis, usually measured as coronary artery calcification, among athletes who are middle-aged and older. Our review of the medical literature demonstrates that the prevalence of coronary artery calcification and atherosclerotic plaques, which are strong predictors for future cardiovascular morbidity and mortality, was higher in athletes compared with controls, and was higher in the most active athletes compared with less active athletes. However, analysis of plaque morphology revealed fewer mixed plaques and more often only calcified plaques among athletes, suggesting a more benign composition of atherosclerotic plaques. This review describes the effects of physical activity and exercise training on coronary atherosclerosis in athletes who are middle-aged and older and aims to contribute to the understanding of the potential adverse effects of the highest doses of exercise training on the coronary arteries. For this purpose, we will review the association between exercise and coronary atherosclerosis measured using computed tomography, discuss the potential underlying mechanisms for exercise-induced coronary atherosclerosis, determine the clinical relevance of coronary atherosclerosis in middle-aged athletes and describe strategies for the clinical management of athletes with coronary atherosclerosis to guide physicians in clinical decision making and treatment of athletes with elevated coronary artery calcification scores.
Topics: Athletes; Computed Tomography Angiography; Coronary Angiography; Coronary Artery Disease; Exercise; Female; Humans; Male; Plaque, Atherosclerotic; Prevalence; Risk Factors; Vascular Calcification
PubMed: 32310695
DOI: 10.1161/CIRCULATIONAHA.119.044467 -
Journal of the American College of... Sep 2019It has been believed that most acute coronary events result from the rupture of mildly stenotic plaques, based on studies in which angiographic information was available... (Review)
Review
It has been believed that most acute coronary events result from the rupture of mildly stenotic plaques, based on studies in which angiographic information was available from many months to years before the event. However, serial studies in which angiographic data were available from the past as also within 1 to 3 months of myocardial infarction have clarified that nonobstructive lesions progressively enlarged relatively rapidly before the acute event occurred. Noninvasive computed tomography angiography imaging data have confirmed that lesions that did not progress voluminously over time rarely led to events, regardless of the extent of luminal stenosis or baseline high-risk plaque morphology. Therefore, plaque progression could be proposed as a necessary step between early, uncomplicated atherosclerosis and plaque rupture. On the other hand, it has been convincingly demonstrated that intensive lipid-lowering therapy (to a low-density lipoprotein cholesterol level of <70 mg/dl) halts plaque progression. Given the current ability to noninvasively detect the presence of early atherosclerosis, the importance of plaque progression in the pathogenesis of myocardial infarction, and the efficacy of maximum lipid-lowering therapy, it has been suggested that plaque progression is a modifiable step in the evolution of atherosclerotic plaque. A personalized approach based on the detection of early atherosclerosis can trigger the necessary treatment to prevent plaque progression and hence plaque instability. Therefore, this approach can redefine the traditional paradigm of primary and secondary prevention based on population-derived risk estimates and can potentially improve long-term outcomes.
Topics: Acute Coronary Syndrome; Acute Disease; Atherosclerosis; Disease Progression; Humans; Plaque, Atherosclerotic
PubMed: 31537271
DOI: 10.1016/j.jacc.2019.08.012 -
Journal of Atherosclerosis and... Jul 2023Intracranial branch atheromatous disease (BAD) is a pathological condition characterized by the occlusion of a relatively large perforating branch (700-800 µm) near the... (Review)
Review
Intracranial branch atheromatous disease (BAD) is a pathological condition characterized by the occlusion of a relatively large perforating branch (700-800 µm) near the orifice of a parent artery due to atherosclerotic plaque-based thrombus (microatheroma). BAD is refractory to treatment and follows a course of progressive exacerbation, especially motor paralysis. Uniform treatment for common atherothrombotic cerebral infarction or lacunar infarction does not prevent the progressive exacerbation of BAD, and consequently affects functional prognosis. To date, various combinations of treatments have been investigated and proposed to attenuate the worsening symptoms of BAD. However, no therapy with established efficacy is yet available for BAD. Since it is the most difficult condition to treat in the area of cerebral infarction, the establishment of optimal treatment methods for BAD is keenly awaited. This review presents an overview of the acute treatments available for BAD and discusses the prospects for optimal treatment.
Topics: Plaque, Atherosclerotic; Humans; Intracranial Thrombosis; Cerebral Infarction; Stroke, Lacunar; Dual Anti-Platelet Therapy
PubMed: 37183021
DOI: 10.5551/jat.RV22003 -
International Journal of Molecular... Apr 2020Atherosclerosis is a lipoprotein-driven inflammatory disorder leading to a plaque formation at specific sites of the arterial tree. After decades of slow progression,... (Review)
Review
Atherosclerosis is a lipoprotein-driven inflammatory disorder leading to a plaque formation at specific sites of the arterial tree. After decades of slow progression, atherosclerotic plaque rupture and formation of thrombi are the major factors responsible for the development of acute coronary syndromes (ACSs). In this regard, the detection of high-risk (vulnerable) plaques is an ultimate goal in the management of atherosclerosis and cardiovascular diseases (CVDs). Vulnerable plaques have specific morphological features that make their detection possible, hence allowing for identification of high-risk patients and the tailoring of therapy. Plaque ruptures predominantly occur amongst lesions characterized as thin-cap fibroatheromas (TCFA). Plaques without a rupture, such as plaque erosions, are also thrombi-forming lesions on the most frequent pathological intimal thickening or fibroatheromas. Many attempts to comprehensively identify vulnerable plaque constituents with different invasive and non-invasive imaging technologies have been made. In this review, advantages and limitations of invasive and non-invasive imaging modalities currently available for the identification of plaque components and morphologic features associated with plaque vulnerability, as well as their clinical diagnostic and prognostic value, were discussed.
Topics: Animals; Atherosclerosis; Biomarkers; Diagnostic Imaging; Disease Susceptibility; Humans; Molecular Imaging; Multimodal Imaging; Plaque, Atherosclerotic; Reproducibility of Results; Sensitivity and Specificity
PubMed: 32340284
DOI: 10.3390/ijms21082992 -
Journal of the American College of... Jun 2023
Topics: Humans; Plaque, Atherosclerotic; Atherosclerosis; Rupture, Spontaneous
PubMed: 37286251
DOI: 10.1016/j.jacc.2023.05.001