The vulnerable coronary plaque: update on imaging technologies

SummarySeveral studies have been carried out on vulnerable plaque as the main culprit for ischaemic cardiac events. Historically, the most important diagnostic technique for studying coronary atherosclerotic disease was to determine the residual luminal diameter by angiographic measurement of the stenosis. However, it has become clear that vulnerable plaque rupture as well as thrombosis, rather than stenosis, triggers most acute ischaemic events and that the quantification of risk based merely on severity of the arterial stenosis is not sufficient. In the last decades, substantial progresses have been made on optimisation of techniques detecting the arterial wall morphology, plaque composition and inflammation. To date, the use of a single technique is not recommended to precisely identify the progression of the atherosclerotic process in human beings. In contrast, the integration of data that can be derived from multiple methods might improve our knowledge about plaque destabilisation. The aim of this narrative review is to update evidence on the accuracy of the currently available non-invasive and invasive imaging techniques in identifying components and morphologic characteristics associated with coronary plaque vulnerability.

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Noninvasive Imaging Biomarkers of Vulnerable Coronary Plaques – a Clinical Update

Journal of Interdisciplinary Medicine ◽

10.2478/jim-2019-0021 ◽

2019 ◽

Vol 4 (3) ◽

pp. 136-140

Author(s):

Noémi Mitra ◽

Daniel Cernica ◽

Roxana Hodas ◽

Monica Chițu ◽

István Kovács ◽

...

Keyword(s):

Plaque Rupture ◽

Imaging Techniques ◽

Noninvasive Imaging ◽

Coronary Plaque ◽

Clinical Event ◽

Significant Advance ◽

Imaging Biomarkers ◽

Cardiac Events ◽

Mortality And Morbidity ◽

Asymptomatic Patients

Abstract Atherosclerosis is a slow, progressive disease, its most common manifestation and most severe consequence being coronary artery disease, one of the main causes of mortality and morbidity worldwide. The vast majority of cardiovascular deaths are caused by complications of atherosclerosis, most often being represented by the rupture of an unstable coronary plaque, regularly triggered by inflammation. A vulnerable plaque is characterized by a large, lipid-rich necrotic core, a thin fibrous cap with macrophage infiltration, and the presence of multiple specific biomarkers such as positive remodeling, irregular calcifications, and low attenuation visible with coronary computed tomography angiography (CCTA). Identifying biomarkers that could predict the risk of plaque rupture with high accuracy would be a significant advance in predicting acute cardiac events in asymptomatic patients, furthermore guiding treatment of patients with this disease. The main indication of noninvasive imaging is to identify patients at risk based on the presence or absence of symptoms that can be related to myocardial ischemia. The diagnostic objective is to confirm or to exclude the presence of coronary plaques. Coronary imaging in asymptomatic individuals is used to estimate the risk of future cardiac events through the identification of non-obstructive high-risk plaques. The possibility to monitor the evolution of vulnerable plaques via noninvasive imaging techniques, prior to the occurrence of an acute clinical event, is the main goal in plaque imaging. This manuscript will be focusing on recent advances of noninvasive imaging of vulnerable coronary plaques.

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Non-invasive imaging of the vulnerable atherosclerotic plaque

The ESC Textbook of Cardiovascular Imaging ◽

10.1093/med/9780198849353.003.0032 ◽

2021 ◽

pp. 467-480

Author(s):

Rong Bing ◽

David E. Newby ◽

Jagat Narula ◽

Marc R. Dweck

Keyword(s):

Atherosclerotic Plaque ◽

Vulnerable Plaque ◽

Plaque Rupture ◽

Imaging Techniques ◽

Risk Scores ◽

Plaque Imaging ◽

Vulnerable Atherosclerotic Plaque ◽

Acute Thrombosis ◽

Non Invasive ◽

Clinical Events

Cardiovascular disease remains the leading cause of death globally despite advances in medical therapy and risk stratification; ischaemic heart disease was responsible for an estimated 9.5 million deaths in 2016. To address this ongoing global burden of morbidity and mortality, there is a need for more sophisticated methods of diagnosis and prognostication, above and beyond clinical risk scores alone. The majority of myocardial infarction occurs due to ruptured atherosclerotic plaque, leading to acute thrombosis and coronary occlusion. For decades, the concept of the vulnerable plaque—plaques prone to rupture or thrombotic complications—has been central to our understanding of the pathophysiology of acute coronary syndromes. More recently, there has been a shift towards identifying the vulnerable patient through assessment of total atherosclerotic disease burden, in recognition of the fact that most plaque rupture events do not lead to clinical events. Moreover, demonstrating a strong causal link between vulnerable plaques and clinical events has previously proven difficult due to limitations in available invasive and non-invasive imaging modalities. However, we now have an array of imaging techniques that hold great potential for the advancement of vulnerable plaque imaging. These modalities are the subject of state-of-the-art clinical research, aiming to develop the role of atherosclerotic plaque imaging in modern clinical practice and ultimately to improve patient outcomes.

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Cardiac involvement in systemic diseases

10.1093/med/9780199599639.003.0020 ◽

2011 ◽

Author(s):

Andreas Hagendorff

Keyword(s):

Cardiac Tissue ◽

Cardiac Involvement ◽

Imaging Techniques ◽

Coronary Thrombosis ◽

Systemic Disease ◽

Diagnostic Technique ◽

Invasive Procedure ◽

Diagnostic Methods ◽

Systemic Diseases ◽

Cardiac Events

Systemic diseases are generally an interdisciplinary challenge in clinical practice. Systemic diseases are able to induce tissue damage in different organs with ongoing duration of the illness. The heart and the circulation are important targets in systemic diseases. The cardiac involvement in systemic diseases normally introduces a chronic process of alterations in cardiac tissue, which causes cardiac failure in the end stage of the diseases or causes dangerous and life-threatening problems by induced acute cardiac events, such as myocardial infarction due to coronary thrombosis. Thus, diagnostic methods—especially imaging techniques—are required, which can be used for screening as well as for the detection of early stages of the diseases. Two-dimensional echocardiography is the predominant diagnostic technique in cardiology for the detection of injuries in cardiac tissue—e.g. the myocardium, endocardium, and the pericardium—due to the overall availability of the non-invasive procedure.The quality of the echocardiography and the success rate of detecting cardiac pathologies in patients with primary non-cardiac problems depend on the competence and expertise of the investigator. Especially in this scenario clinical knowledge about the influence of the systemic disease on cardiac anatomy and physiology is essential for central diagnostic problem. Therefore the primary echocardiography in these patients should be performed by an experienced clinician or investigator. It is possible to detect changes of cardiac morphology and function at different stages of systemic diseases as well as complications of the systemic diseases by echocardiography.The different parts of this chapter will show proposals for qualified transthoracic echocardiography focusing on cardiac structures which are mainly involved in different systemic diseases.

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Colchicine Use in Acute Coronary Syndromes: An Update

Angiology ◽

10.1177/0003319720985644 ◽

2021 ◽

pp. 000331972098564

Author(s):

Laura Tapoi ◽

Laura Benchea ◽

Dimitrie Siriopol ◽

Mehmet Kanbay ◽

Adrian Covic

Keyword(s):

Acute Coronary Syndromes ◽

Coronary Intervention ◽

Coronary Plaque ◽

Present Moment ◽

Cardiac Events ◽

Adverse Cardiac Events ◽

Acute Mi ◽

Coronary Syndromes ◽

Artery Disease ◽

Atherosclerotic Process

Coronary artery disease is the leading cause of death worldwide, and its main pathological substrate is represented by atherosclerosis. Inflammation is a major promoter of the atherosclerotic process and is involved in both the initiation and progression of atherosclerosis, as well as in the occurrence of fatal complications. Until the present moment, Colchicine Cardiovascular Outcomes Trial is the largest trial to demonstrate a major benefit of low-dose colchicine on major adverse cardiac events in patients with recent myocardial infarction (MI), but the mechanisms behind this relation are not completely known. The purpose of this review is to emphasize the possible pathways through which colchicine improves the clinical outcomes in the acute setting of acute coronary syndromes by referring to the results of the studies published in the past 5 years. Aside from its stated systemic anti-inflammatory effect, colchicine could be a valuable addition to the therapeutic approach of acute MI by reducing the infarct size, stabilizing the coronary plaque, as well as reducing platelet aggregation. Moreover, colchicine may improve endothelial function, reduce the transcoronary release of cytokines, and prevent a rise in inflammatory markers after percutaneous coronary intervention, thus diminishing the residual inflammatory risk.

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Texture Analysis and Classification of Coronary Plaque in Intravascular Ultrasound

Microscopy and Microanalysis ◽

10.1017/s1431927600008217 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 265-266

Author(s):

K. J. Dixon ◽

D. G. Vince ◽

R. M. Cothren ◽

J. F. Cornhill

Keyword(s):

Intravascular Ultrasound ◽

Coronary Arteries ◽

Imaging System ◽

Plaque Rupture ◽

Ultrasound Image ◽

Diagnostic Technique ◽

Coronary Plaque ◽

Arterial Disease ◽

Plaque Morphology ◽

Ultrasound Images

Atherosclerosis is a degenerative arterial disease that leads to the gradual blockage of vessels due to plaque formation or acute ischaemic events such as plaque rupture. A thorough understanding of plaque morphology is necessary in the determination of factors underlying coronary artery disease. Intravascular ultrasound (IVUS) represents a diagnostic technique that provides tomographic visualization of coronary arteries. Ultrasound reflects sound at the interfaces between media of different acoustic refractive indices theoretically implying that various components within an ultrasound image should be distinguishable. The aim of this study is to classify plaque lesions using advanced digital image processing into the following categories: adventitia, media, fibrous, necrotic core, and calcified. Examination of plaque composition can yield valuable information necessary in determining the appropriate preventative and mechanical interventions.Diseased samples were obtained from excised human coronary arteries at autopsy. Intravascular ultrasound images were acquired using an HP SONOS clinical IVUS imaging system and 3.5 French 30 MHz catheters.

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Vulnerable Plaque Rupture Due to Stress Concentration Around Microcalcifications in the Thin Fibrous Cap

ASME 2007 Summer Bioengineering Conference ◽

10.1115/sbc2007-176283 ◽

2007 ◽

Author(s):

Yuliya Vengrenyuk ◽

Luis Cardoso Landa ◽

Stéphane Carlier ◽

Shmuel Einav ◽

Sheldon Weinbaum

Keyword(s):

Vulnerable Plaque ◽

Vessel Wall ◽

Plaque Rupture ◽

Coronary Plaque ◽

Vasa Vasorum ◽

Structure Interaction ◽

Fibrous Cap ◽

Maximal Stress ◽

Artery Disease ◽

Tissue Stresses

More than half of the 500,000 coronary artery disease deaths every year are due to the sudden rupture of vulnerable plaque. Several pathological studies of ruptured plaques have provided morphological descriptions of the high-risk, or vulnerable, coronary plaque that is prone to rupture or erosion as a positively remodeled lesion rich in vasa-vasorum, containing a lipid-rich core with an overlying thin fibrous cap infiltrated by macrophages. Virmani et al. [1] described thin-cap fibroatheroma with a large necrotic core and a fibrous cap < 65 μm as a more specific precursor of plaque rupture due to tissue stress. Despite the above observations, the mechanism of vulnerable plaque rupture has remained a mystery since ruptures often occur in regions where computational finite element (FEM) and fluid structure interaction (FSI) models do not predict maximal stress. Forty percent of ruptures occur in the central part of the cap rather than regions of high curvature at the shoulders of the lipid core where FEM models predict maximum tissue stresses [2]. Similarly, the latest study by Tang et al. [3] predicts that maximal stress often appears at healthy parts of the vessel where the vessel wall is thinner than the wall on the diseased plaque side or where vessel wall curvature is large.

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Coronary Atherosclerosis Imaging

Diagnostics ◽

10.3390/diagnostics10020065 ◽

2020 ◽

Vol 10 (2) ◽

pp. 65 ◽

Cited By ~ 2

Author(s):

Michael Y. Henein ◽

Sergio Vancheri ◽

Gani Bajraktari ◽

Federico Vancheri

Keyword(s):

Coronary Artery ◽

Plaque Rupture ◽

Imaging Techniques ◽

Plaque Morphology ◽

Limited Information ◽

Cardiac Events ◽

Luminal Narrowing ◽

Increased Risk ◽

Coronary Events ◽

Atherosclerosis Imaging

Identifying patients at increased risk of coronary artery disease, before the atherosclerotic complications become clinically evident, is the aim of cardiovascular prevention. Imaging techniques provide direct assessment of coronary atherosclerotic burden and pathological characteristics of atherosclerotic lesions which may predict the progression of disease. Atherosclerosis imaging has been traditionally based on the evaluation of coronary luminal narrowing and stenosis. However, the degree of arterial obstruction is a poor predictor of subsequent acute events. More recent techniques focus on the high-resolution visualization of the arterial wall and the coronary plaques. Most acute coronary events are triggered by plaque rupture or erosion. Hence, atherosclerotic plaque imaging has generally focused on the detection of vulnerable plaque prone to rupture. However, atherosclerosis is a dynamic process and the plaque morphology and composition may change over time. Most vulnerable plaques undergo progressive transformation from high-risk to more stable and heavily calcified lesions, while others undergo subclinical rupture and healing. Although extensive plaque calcification is often associated with stable atherosclerosis, the extent of coronary artery calcification strongly correlates with the degree of atherosclerosis and with the rate of future cardiac events. Inflammation has a central role in atherogenesis, from plaque formation to rupture, hence in the development of acute coronary events. Morphologic plaque assessment, both invasive and non-invasive, gives limited information as to the current activity of the atherosclerotic disease. The addition of nuclear imaging, based on radioactive tracers targeted to the inflammatory components of the plaques, provides a highly sensitive assessment of coronary disease activity, thus distinguishing those patients who have stable disease from those with active plaque inflammation.

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Macrophage infiltrates in coronary plaque erosion portend a worse cardiovascular outcome in patients with acute coronary syndrome

European Heart Journal ◽

10.1093/ehjci/ehaa946.1250 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

R.A Montone ◽

V Vetrugno ◽

M Camilli ◽

M Russo ◽

M.G Del Buono ◽

...

Keyword(s):

Acute Coronary Syndrome ◽

Vulnerable Plaque ◽

Cardiac Death ◽

Cox Regression ◽

Plaque Rupture ◽

Culprit Lesion ◽

Coronary Syndrome ◽

Fibrous Cap ◽

Plaque Erosion

Abstract Background Plaque erosion (PE) is responsible for at least one-third of acute coronary syndrome (ACS). Inflammatory activation is considered a key mechanism of plaque instability in patients with plaque rupture through the release of metalloproteinases and the inhibition of collagen synthesis that in turns lead to fibrous cap degradation. However, the clinical relevance of macrophage infiltration has never been investigated in patients with PE. Purpose In our study, we aimed at assessing the presence of optical coherence tomography (OCT)-defined macrophage infiltrates (MØI) at the culprit site in ACS patients with PE, evaluating their clinical and OCT correlates, along with their prognostic value. Methods ACS patients undergoing OCT imaging and presenting PE as culprit lesion were retrospectively selected. Presence of MØI at culprit site and in non-culprit segments along the culprit vessel was assessed. The incidence of major adverse cardiac events (MACEs), defined as the composite of cardiac death, recurrent myocardial infarction and target vessel revascularization (TVR), was assessed [follow-up median (interquartile range, IQR) time 2.5 (2.03–2.58) years]. Results We included 153 patients [median age (IQR) 64 (53–75) years, 99 (64.7%) males]. Fifty-one (33.3%) patients presented PE with MØI and 102 (66.7%) PE without MØI. Patients having PE with MØI compared with PE patients without MØI had more vulnerable plaque features both at culprit site and at non-culprit segments. In particular, culprit lesion analysis demonstrated that patients with PE with MØI had a significantly thinner fibrous cap [median (IQR) 100 (60–120) μm vs. 160 (95–190) μm, p<0.001], higher prevalence of thrombus [41 (80.4%) vs. 64 (62.7%), p=0.028], lipid plaque [39 (76.5%) vs. 50 (49.0%), p<0.001], TCFA [20 (39.2%) vs. 14 (13.7%), p=0.001], and a higher maximum lipid arc [median [IQR] 250.0° (177.5°-290.0°) vs. 190.0° (150.0°-260.0°), p=0.018) at the culprit lesion compared with PE without MØI. MACEs were significantly more frequent in PE with MØI patients compared with PE without MØI [11 (21.6%) vs. 6 (5.9%), p=0.008], mainly driven by a higher risk of cardiac death and TVR. At multivariable Cox regression model, PE with MØI [HR=2.95, 95% CI (1.09–8.02), p=0.034] was an independent predictor of MACEs. Conclusion Our study demonstrates that among ACS patients with PE the presence of MØI at culprit lesion is associated with a more aggressive phenotype of coronary atherosclerosis with more vulnerable plaque features, along with a worse prognosis at a long-term follow-up. These findings are of the utmost importance in the era of precision medicine because clearly show that macrophage infiltrates may identify patients with a higher cardiovascular risk requiring more aggressive secondary prevention therapies and a closer clinical follow-up. Prognosis Funding Acknowledgement Type of funding source: None

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Non-radioactive imaging strategies for in vivo immune cell tracking

Physical Sciences Reviews ◽

10.1515/psr-2020-0205 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Łukasz Kiraga ◽

Paulina Kucharzewska ◽

Damian Strzemecki ◽

Tomasz P. Rygiel ◽

Magdalena Król

Keyword(s):

Diagnostic Imaging ◽

Contrast Agents ◽

Cell Tracking ◽

Immune Cell ◽

Imaging Techniques ◽

Diagnostic Technique ◽

Cell Labeling ◽

X Ray Imaging ◽

Disease Study

Abstract In vivo tracking of administered cells chosen for specific disease treatment may be conducted by diagnostic imaging techniques preceded by cell labeling with special contrast agents. The most commonly used agents are those with radioactive properties, however their use in research is often impossible. This review paper focuses on the essential aspect of cell tracking with the exclusion of radioisotope tracers, therefore we compare application of different types of non-radioactive contrast agents (cell tracers), methods of cell labeling and application of various techniques for cell tracking, which are commonly used in preclinical or clinical studies. We discuss diagnostic imaging methods belonging to three groups: (1) Contrast-enhanced X-ray imaging, (2) Magnetic resonance imaging, and (3) Optical imaging. In addition, we present some interesting data from our own research on tracking immune cell with the use of discussed methods. Finally, we introduce an algorithm which may be useful for researchers planning leukocyte targeting studies, which may help to choose the appropriate cell type, contrast agent and diagnostic technique for particular disease study.

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