In vivo predictors of plaque erosion in patients with ST-segment elevation myocardial infarction: a clinical, angiographical, and intravascular optical coherence tomography study

Endothelial-to-Mesenchymal Transition in Cardiovascular Pathophysiology

Under different pathophysiological conditions, endothelial cells lose endothelial phenotype and gain mesenchymal cell-like phenotype via a process known as endothelial-to-mesenchymal transition (EndMT). At the molecular level, endothelial cells lose the expression of endothelial cell-specific markers such as CD31/platelet-endothelial cell adhesion molecule, von Willebrand factor, and vascular-endothelial cadherin and gain the expression of mesenchymal cell markers such as α-smooth muscle actin, N-cadherin, vimentin, fibroblast specific protein-1, and collagens. EndMT is induced by numerous different pathways triggered and modulated by multiple different and often redundant mechanisms in a context-dependent manner depending on the pathophysiological status of the cell. EndMT plays an essential role in embryonic development, particularly in atrioventricular valve development; however, EndMT is also implicated in the pathogenesis of several genetically determined and acquired diseases, including malignant, cardiovascular, inflammatory, and fibrotic disorders. Among cardiovascular diseases, aberrant EndMT is reported in atherosclerosis, pulmonary hypertension, valvular disease, fibroelastosis, and cardiac fibrosis. Accordingly, understanding the mechanisms behind the cause and/or effect of EndMT to eventually target EndMT appears to be a promising strategy for treating aberrant EndMT-associated diseases. However, this approach is limited by a lack of precise functional and molecular pathways, causes and/or effects, and a lack of robust animal models and human data about EndMT in different diseases. Here, we review different mechanisms in EndMT and the role of EndMT in various cardiovascular diseases.

Atherosclerotic Plaque Erosion: Mechanisms, Clinical Implications, and Potential Therapeutic Strategies-A Review

ABSTRACT

Atherosclerosis is an insidious and progressive inflammatory disease characterized by the formation of lipid-laden plaques within the intima of arterial walls with potentially devastating consequences. While rupture of vulnerable plaques has been extensively studied, a distinct mechanism known as plaque erosion (PE) has gained recognition and attention in recent years. PE, characterized by the loss of endothelial cell lining in the presence of intact fibrous cap, contributes to a significant and growing proportion of acute coronary events. However, despite a heterogeneous substrate underlying coronary thrombosis, treatment remains identical. This article provides an overview of atherosclerotic PE characteristics and its underlying mechanisms, highlights its clinical implications, and discusses potential therapeutic strategies.

Intravascular Imaging in the Diagnosis and Management of Patients With Suspected Intracoronary Pathologies: A CJC White Paper

Intravascular imaging has become an integral part of the diagnostic and management strategies for intracoronary pathologies. In this White Paper we summarize current evidence and its implications on the use of intravascular imaging in interventional cardiology practice. The areas addressed are planning and optimization of percutaneous coronary intervention, management of stent failure, and evaluation of ambiguous coronary lesions and myocardial infarction with nonobstructive coronary disease. The findings presented followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system in an expert consensus process that involved a diverse writing group vetted by a review group. Expert consensus was achieved around 9 statements. Use of intravascular imaging in guiding percutaneous revascularization is supported by high-quality evidence, particularly for lesions with increased risk of recurrent events or stent failure. Specific considerations for intravascular imaging guidance of intervention in left main lesions, chronic occlusion lesions, and in patients at high risk of contrast nephropathy are explored. Use of intravascular imaging to identify pathologies associated with stent failure and guide repeat intervention, resolve ambiguities in lesion assessment, and establish diagnoses in patients who present with myocardial infarction with nonobstructive coronary disease is supported by moderate- to low-quality evidence. Each topic is accompanied by clinical pointers to aid the practicing interventional cardiologist in implementation of the White Paper findings. The findings presented in this White Paper will help to guide the use of intravascular imaging toward situations in which the balance of efficacy, safety, and cost are most optimal.

Coronary Plaque Erosion: Epidemiology, Diagnosis, and Treatment

Plaque erosion (PE), a distinct etiology of acute coronary syndromes (ACSs), is often overshadowed by plaque ruptures (PRs). Concerning its epidemiology, PE has garnered increasing recognition, with recent studies revealing its prevalence to be approximately 40% among ACS patients, challenging earlier assumptions based on autopsy data. Notably, PE exhibits distinct epidemiological features, preferentially affecting younger demographics, particularly women, and often manifesting as a non-ST-segment elevation myocardial infarction. There are seasonal variations, with PE events being less common in winter, potentially linked to physiological changes and cholesterol solidification, while peaking in summer, warranting further investigation. Moving to molecular mechanisms, PE presents a unique profile characterized by a lesser degree of inflammation compared to PR, with endothelial shear stress emerging as a plausible molecular mechanism. Neutrophil activation, toll-like receptor-2 pathways, and hyaluronidase 2 expression are among the factors implicated in PE pathophysiology, underscoring its multifactorial nature. Advancements in intravascular imaging diagnostics, particularly optical coherence tomography and near-infrared spectroscopy coupled with intravascular ultrasound, offer unprecedented insights into plaque composition and morphology. Artificial intelligence algorithms show promise in enhancing diagnostic accuracy and streamlining image interpretation, augmenting clinician decision-making. Therapeutically, the management of PE evolves, with studies exploring less invasive approaches such as antithrombotic therapy without stenting, particularly in cases identified early through intravascular imaging. Additionally, the potential role of drug-coated balloons in reducing thrombus burden and minimizing future major adverse cardiovascular events warrants further investigation. Looking ahead, the integration of advanced imaging modalities, biomarkers, and artificial intelligence promises to revolutionize the diagnosis and treatment of coronary PE, ushering in a new era of personalized and precise cardiovascular care.

Cardiac Optical Coherence Tomography: History, Current Status, and Perspective

For more than 2 decades since the first imaging procedure was performed in a living patient, intravascular optical coherence tomography (OCT), with its unprecedented image resolution, has made significant contributions to cardiovascular medicine in the realms of vascular biology research and percutaneous coronary intervention. OCT has contributed to a better understanding of vascular biology by providing insights into the pathobiology of atherosclerosis, including plaque phenotypes and the underlying mechanisms of acute coronary syndromes such as plaque erosion, neoatherosclerosis, stent thrombosis, and myocardial infarction with nonobstructive coronary arteries. Moreover, OCT has been used as an adjunctive imaging tool to angiography for the guidance of percutaneous coronary intervention procedures to optimize outcomes. However, broader application of OCT has faced challenges, including subjective interpretation of the images and insufficient clinical outcome data. Future developments including artificial intelligence-assisted interpretation, multimodality catheters, and micro-OCT, as well as large prospective outcome studies could broaden the impact of OCT on cardiovascular medicine.

Coronary microevaginations characterize culprit plaques and their inflammatory microenvironment in a subtype of acute coronary syndrome with intact fibrous cap: results from the prospective translational OPTICO-ACS study

AIMS

Coronary microevaginations (CMEs) represent an outward bulge of coronary plaques and have been introduced as a sign of adverse vascular remodelling following coronary device implantation. However, their role in atherosclerosis and plaque destabilization in the absence of coronary intervention is unknown. This study aimed to investigate CME as a novel feature of plaque vulnerability and to characterize its associated inflammatory cell-vessel-wall interactions.

METHODS AND RESULTS

A total of 557 patients from the translational OPTICO-ACS study programme underwent optical coherence tomography imaging of the culprit vessel and simultaneous immunophenotyping of the culprit lesion (CL). Two hundred and fifty-eight CLs had a ruptured fibrous cap (RFC) and one hundred had intact fibrous cap (IFC) acute coronary syndrome (ACS) as an underlying pathophysiology. CMEs were significantly more frequent in CL when compared with non-CL (25 vs. 4%, P < 0.001) and were more frequently observed in lesions with IFC-ACS when compared with RFC-ACS (55.0 vs. 12.7%, P < 0.001). CMEs were particularly prevalent in IFC-ACS-causing CLs independent of a coronary bifurcation (IFC-ICB) when compared with IFC-ACS with an association to a coronary bifurcation (IFC-ACB, 65.4 vs. 43.7%, P = 0.030). CME emerged as the strongest independent predictor of IFC-ICB (relative risk 3.36, 95% confidence interval 1.67-6.76, P = 0.001) by multivariable regression analysis. IFC-ICB demonstrated an enrichment of monocytes in both culprit blood analysis (culprit ratio: 1.1 ± 0.2 vs. 0.9 ± 0.2, P = 0.048) and aspirated culprit thrombi (326 ± 162 vs. 96 ± 87 cells/mm2, P = 0.017), while IFC-ACB confirmed the accumulation of CD4+ T cells, as recently described.

CONCLUSION

This study provides novel evidence for a pathophysiological involvement of CME in the development of IFC-ACS and provides first evidence for a distinct pathophysiological pathway for IFC-ICB, driven by CME-derived flow disturbances and inflammatory activation involving the innate immune system.

TRIAL REGISTRATION

Registration of the study at clinicalTrials.gov (NCT03129503).

Platelet biology and function: plaque erosion vs. rupture

The leading cause of heart disease in developed countries is coronary atherosclerosis, which is not simply a result of ageing but a chronic inflammatory process that can lead to acute clinical events upon atherosclerotic plaque rupture or erosion and arterial thrombus formation. The composition and location of atherosclerotic plaques determine the phenotype of the lesion and whether it is more likely to rupture or to erode. Although plaque rupture and erosion both initiate platelet activation on the exposed vascular surface, the contribution of platelets to thrombus formation differs between the two phenotypes. In this review, plaque phenotype is discussed in relation to thrombus composition, and an overview of important mediators (haemodynamics, matrix components, and soluble factors) in plaque-induced platelet activation is given. As thrombus formation on disrupted plaques does not necessarily result in complete vessel occlusion, plaque healing can occur. Therefore, the latest findings on plaque healing and the potential role of platelets in this process are summarized. Finally, the clinical need for more effective antithrombotic agents is highlighted.

A novel deep learning model for a computed tomography diagnosis of coronary plaque erosion

Patients with acute coronary syndromes caused by plaque erosion might be managed conservatively without stenting. Currently, the diagnosis of plaque erosion requires an invasive imaging procedure. We sought to develop a deep learning (DL) model that enables an accurate diagnosis of plaque erosion using coronary computed tomography angiography (CTA). A total of 532 CTA scans from 395 patients were used to develop a DL model: 426 CTA scans from 316 patients for training and internal validation, and 106 separate scans from 79 patients for validation. Momentum Distillation-enhanced Composite Transformer Attention (MD-CTA), a novel DL model that can effectively process the entire set of CTA scans to diagnose plaque erosion, was developed. The novel DL model, compared to the convolution neural network, showed significantly improved AUC (0.899 [0.841-0.957] vs. 0.724 [0.622-0.826]), sensitivity (87.1 [70.2-96.4] vs. 71.0 [52.0-85.8]), and specificity (85.3 [75.3-92.4] vs. 68.0 [56.2-78.3]), respectively, for the patient-level prediction. Similar results were obtained at the slice-level prediction AUC (0.897 [0.890-0.904] vs. 0.757 [0.744-0.770]), sensitivity (82.2 [79.8-84.3] vs. 68.9 [66.2-71.6]), and specificity (80.1 [79.1-81.0] vs. 67.3 [66.3-68.4]), respectively. This newly developed DL model enables an accurate CT diagnosis of plaque erosion, which might enable cardiologists to provide tailored therapy without invasive procedures.Clinical Trial Registration: http://www.clinicaltrials.gov , NCT04523194.

Diagnosis and Prognostic Value of the Underlying Cause of Acute Coronary Syndrome in Optical Coherence Tomography-Guided Emergency Percutaneous Coronary Intervention

Background The prognostic impact of optical coherence tomography-diagnosed culprit lesion morphology in acute coronary syndrome (ACS) has not been systematically examined in real-world settings. Methods and Results This investigator-initiated, prospective, multicenter, observational study was conducted at 22 Japanese hospitals to identify the prevalence of underlying ACS causes (plaque rupture [PR], plaque erosion [PE], and calcified nodules [CN]) and their impact on clinical outcomes. Patients with ACS diagnosed within 24 hours of symptom onset undergoing emergency percutaneous coronary intervention were enrolled. Optical coherence tomography-guided percutaneous coronary intervention recipients were assessed for underlying ACS causes and followed up for major adverse cardiac events (cardiovascular death, myocardial infarction, heart failure, or ischemia-driven revascularization) at 1 year. Of 1702 patients with ACS, 702 (40.7%) underwent optical coherence tomography-guided percutaneous coronary intervention for analysis. PR, PE, and CN prevalence was 59.1%, 25.6%, and 4.0%, respectively. One-year major adverse cardiac events occurred most frequently in patients with CN (32.1%), followed by PR (12.4%) and PE (6.2%) (log-rank P<0.0001), primarily driven by increased cardiovascular death (CN, 25.0%; PR, 0.7%; PE, 1.1%; log-rank P<0.0001) and heart failure trend (CN, 7.1%; PR, 6.8%; PE, 2.2%; log-rank P<0.075). On multivariate Cox regression analysis, the underlying ACS cause was associated with 1-year major adverse cardiac events (CN [hazard ratio (HR), 4.49 [95% CI, 1.35-14.89], P=0.014]; PR (HR, 2.18 [95% CI, 1.05-4.53], P=0.036]; PE as reference). Conclusions Despite being the least common, CN was a clinically significant underlying ACS cause, associated with the highest future major adverse cardiac events risk, followed by PR and PE. Future studies should evaluate the possibility of ACS underlying cause-based optical coherence tomography-guided optimization.

Culprit plaque morphology determines inflammatory risk and clinical outcomes in acute coronary syndrome

AIMS

Rupture of the fibrous cap (RFC) and erosion of an intact fibrous cap (IFC) are the two predominant mechanisms causing acute coronary syndromes (ACS). It is uncertain whether clinical outcomes are different following RFC-ACS vs. IFC-ACS and whether this is affected by a specific inflammatory response. The prospective, translational OPTIcal-COherence Tomography in Acute Coronary Syndrome study programme investigates the impact of the culprit lesion phenotype on inflammatory profiles and prognosis in ACS patients.

METHODS AND RESULTS

This analysis included 398 consecutive ACS patients, of which 62% had RFC-ACS and 25% had IFC-ACS. The primary endpoint was a composite of cardiac death, recurrent ACS, hospitalization for unstable angina, and target vessel revascularization at 2 years [major adverse cardiovascular events (MACE+)]. Inflammatory profiling was performed at baseline and after 90 days. Patients with IFC-ACS had lower rates of MACE+ than those with RFC-ACS (14.3% vs. 26.7%, P = 0.02). In 368-plex proteomic analyses, patients with IFC-ACS showed lower inflammatory proteome expression compared with those with RFC-ACS, including interleukin-6 and proteins associated with the response to interleukin-1β. Circulating plasma levels of interleukin-1β decreased from baseline to 3 months following IFC-ACS (P < 0.001) but remained stable following RFC-ACS (P = 0.25). Interleukin-6 levels decreased in patients with RFC-ACS free of MACE+ (P = 0.01) but persisted high in those with MACE+.

CONCLUSION

This study demonstrates a distinct inflammatory response and a lower risk of MACE+ following IFC-ACS. These findings advance our understanding of inflammatory cascades associated with different mechanisms of plaque disruption and provide hypothesis generating data for personalized anti-inflammatory therapeutic allocation to ACS patients, a strategy that merits evaluation in future clinical trials.

Peripheral atherosclerosis in acute coronary syndrome patients with plaque rupture vs plaque erosion: A prospective coronary optical coherence tomography and peripheral ultrasound study

BACKGROUND

Plaque rupture (PR) and plaque erosion (PE) are 2 distinct, different, and most common culprit lesion morphologies responsible for acute coronary syndrome (ACS). However, the prevalence, distribution, and characteristics of peripheral atherosclerosis in ACS patients with PR vs PE has never been studied. The aim of this study was to assess peripheral atherosclerosis burden and vulnerability evaluated by vascular ultrasound in ACS patients with coronary PR vs PE identified by optical coherence tomography (OCT).

METHODS

Between October 2018 and December 2019, 297 ACS patients who underwent preintervention OCT examination of the culprit coronary artery were enrolled. Peripheral ultrasound examinations of carotid, femoral, and popliteal arteries were performed before discharge.

RESULTS

Overall, 265 of 297 (89.2%) patients had at least one atherosclerotic plaque in a peripheral arterial bed. Compared with coronary PE, patients with coronary PR had a higher prevalence of peripheral atherosclerotic plaques (93.4% vs 79.1%, P < .001), regardless of location: carotid, femoral, or popliteal arteries. The number of peripheral plaques per patient was significantly larger in the coronary PR group than coronary PE (4 [2-7] vs 2 [1-5], P < .001). Additionally, there was a greater prevalence of peripheral vulnerable characteristics including plaque surface irregularity, heterogeneous plaque, and calcification in patients with coronary PR vs PE.

CONCLUSIONS

Peripheral atherosclerosis exists commonly in patients presenting with ACS. Patients with coronary PR had greater peripheral atherosclerosis burden and more peripheral vulnerability compared to those with coronary PE, suggesting that comprehensive evaluation of peripheral atherosclerosis and multidisciplinary cooperative management maybe necessary, especially in patients with PR.

TRIAL REGISTRATION

clinicaltrials.gov (NCT03971864).

A Nrf2-OSGIN1&2-HSP70 axis mediates cigarette smoke-induced endothelial detachment: implications for plaque erosion

AIMS

Endothelial erosion of plaques is responsible for ∼30% of acute coronary syndromes (ACS). Smoking is a risk factor for plaque erosion, which most frequently occurs on the upstream surface of plaques where the endothelium experiences elevated shear stress. We sought to recreate these conditions in vitro to identify potential pathological mechanisms that might be of relevance to plaque erosion.

METHODS AND RESULTS

Culturing human coronary artery endothelial cells (HCAECs) under elevated flow (shear stress of 7.5 Pa) and chronically exposing them to cigarette smoke extract (CSE) and tumour necrosis factor-alpha (TNFα) recapitulated a defect in HCAEC adhesion, which corresponded with augmented Nrf2-regulated gene expression. Pharmacological activation or adenoviral overexpression of Nrf2 triggered endothelial detachment, identifying Nrf2 as a mediator of endothelial detachment. Growth/Differentiation Factor-15 (GDF15) expression was elevated in this model, with protein expression elevated in the plasma of patients experiencing plaque erosion compared with plaque rupture. The expression of two Nrf2-regulated genes, OSGIN1 and OSGIN2, was increased by CSE and TNFα under elevated flow and was also elevated in the aortas of mice exposed to cigarette smoke in vivo. Knockdown of OSGIN1&2 inhibited Nrf2-induced cell detachment. Overexpression of OSGIN1&2 induced endothelial detachment and resulted in cell cycle arrest, induction of senescence, loss of focal adhesions and actin stress fibres, and disturbed proteostasis mediated in part by HSP70, restoration of which reduced HCAEC detachment. In ACS patients who smoked, blood concentrations of HSP70 were elevated in plaque erosion compared with plaque rupture.

CONCLUSION

We identified a novel Nrf2-OSGIN1&2-HSP70 axis that regulates endothelial adhesion, elevated GDF15 and HSP70 as biomarkers for plaque erosion in patients who smoke, and two therapeutic targets that offer the potential for reducing the risk of plaque erosion.

Pathophysiology of Acute Coronary Syndromes-Diagnostic and Treatment Considerations

Coronary artery disease and acute coronary syndromes are accountable for significant morbidity and mortality, despite the preventive measures and technological advancements in their management. Thus, it is mandatory to further explore the pathophysiology in order to provide tailored and more effective therapies, since acute coronary syndrome pathogenesis is more varied than previously assumed. It consists of plaque rupture, plaque erosion, and calcified nodules. The advancement of vascular imaging tools has been critical in this regard, redefining the epidemiology of each mechanism. When it comes to acute coronary syndrome management, the presence of ruptured plaques almost always necessitates emergent reperfusion, whereas the presence of plaque erosions may indicate the possibility of conservative management with potent antiplatelet and anti-atherosclerotic medications. Calcified nodules, on the other hand, are an uncommon phenomenon that has largely gone unexplored in terms of the best management plan. Future studies should further establish the importance of detecting the underlying mechanism and the role of various treatment plans in each of these distinct entities.

Plexin D1 mediates disturbed flow-induced M1 macrophage polarization in atherosclerosis

Atherosclerosis preferentially develops at bifurcations exposed to disturbed flow. Plexin D1 (PLXND1) responds to mechanical forces and drives macrophage accumulation in atherosclerosis. Here, multiple strategies were used to identify the role of PLXND1 in site-specific atherosclerosis. Using computational fluid dynamics and three-dimensional light-sheet fluorescence-microscopy, the elevated PLXND1 in M1 macrophages was mainly distributed in disturbed flow area of ApoE^-/- carotid bifurcation lesions, and visualization of atherosclerosis in vivo was achieved by targeting PLXND1. Subsequently, to simulate the microenvironment of bifurcation lesions in vitro, we co-cultured oxidized low-density lipoprotein (oxLDL)-treated THP-1-derived macrophages with shear-treated human umbilical vein endothelial cells (HUVECs). We found that oscillatory shear induced the increase of PLXND1 in M1 macrophages, and knocking down PLXND1 inhibited M1 polarization. Semaphorin 3E, the ligand of PLXND1 which was highly expressed in plaques, strongly enhanced M1 macrophage polarization via PLXND1 in vitro. Our findings provide insights into pathogenesis in site-specific atherosclerosis that PLXND1 mediates disturbed flow-induced M1 macrophage polarization.

Utility of optical coherence tomography in acute coronary syndromes

Studies utilizing intravascular imaging have replicated the findings of histopathological studies, identifying the most common substrates for acute coronary syndromes (ACS) as plaque rupture, erosion, and calcified nodule, with spontaneous coronary artery dissection, coronary artery spasm, and coronary embolism constituting the less common etiologies. The purpose of this review is to summarize the data from clinical studies that have used high-resolution intravascular optical coherence tomography (OCT) to assess culprit plaque morphology in ACS. In addition, we discuss the utility of intravascular OCT for effective treatment of patients presenting with ACS, including the possibility of culprit lesion-based treatment by percutaneous coronary intervention.

Current Role of Intracoronary Imaging for Implementing Risk Stratification and Tailoring Culprit Lesion Treatment: A Narrative Review

Our understanding of the pathophysiology of acute coronary syndrome and of the vascular biology of coronary atherosclerosis has made enormous progress with the implementation of intravascular imaging. Intravascular imaging contributes to overcoming the known limitations of coronary angiography and allows for the in vivo discrimination of plaque morphology giving insight into the underlying pathology of the disease process. The possibility of using intracoronary imaging to characterize lesion morphologies and correlate them with clinical presentations may influence the treatment of patients and improve risk stratification, offering the opportunity for tailored management. This review examines the current role of intravascular imaging and describes how intracoronary imaging represents a valuable tool for modern interventional cardiology in order to improve diagnostic accuracy and offer a tailored approach to the treatment of patients with coronary artery disease, especially in the acute setting.

Role of Intracoronary Imaging in Myocardial Infarction with Non-Obstructive Coronary Disease (MINOCA): A Review

Myocardial infarction with non-obstructive coronary artery disease occurs in 6% to 15% of all presentation of myocardial infarctions. The pathophysiologic mechanisms of MINOCA include epicardial vasospasm, coronary microvascular disorder, spontaneous coronary artery dissection, and coronary thrombus/embolism. The diagnosis is challenging, supported by intracoronary imaging with intravascular ultrasound (IVUS) and optical coherent tomography (OCT), coronary physiology testing, and cardiac magnetic resonance imaging (CMR). OCT is able to identify atherosclerotic causes of MINOCA (plaque erosion, plaque rupture, and calcified nodule) and nonatherosclerotic causes (spontaneous artery dissection, and spasm). In this review, we summarize the performance of the two intracoronary imaging modalities (IVUS and OCT) in MINOCA and discuss the importance of supplementing these modalities with CMR in order to drive target therapy.

Interleukin-10 -1082 G/A polymorphism and its association with early or severe presentation of coronary artery disease: A systematic review and meta-analysis

INTRODUCTION

Interleukin-10 (IL-10) is an anti-inflammatory cytokine with potent deactivating properties on macrophages and T cells; and plays an important role in atherosclerotic plaque maturation and rupture. A guanine (G) to adenine (A) substitution in the IL-10 gene at -1082 bp (rs1800896) has been associated with reduced in IL-10 production in vitro. Against this background, we tested the association of IL-10 -1082G/A with early or severe presentation of coronary artery disease (CAD) using a systematic review and updated meta-analysis of published association studies.

MATERIALS AND METHODS

Relevant studies were identified following a comprehensive online search on PubMed, EMBASE, MEDLINE, Scopus, Cochrane library and Web of Science databases and stratified into two subgroups based on mode of CAD presentation: early or severe and non-severe. Study level odds ratios (ORs) and their 95% confidence intervals (CI) were pooled using random effects employing a Z test.

RESULTS

A total of 24 studies were included for quantitative synthesis with a cumulative sample of 19,135 (11,143 cases / 7,992 controls). A significant association was derived for IL-10 -1082G/A and early or severe CAD via dominant, recessive, and allelic genetic model comparisons [OR 1.24 (95 % CI 1.02, 1.50), p = 0.03; OR 1.32 (95 % CI 1.03, 1.69), p = 0.03 and OR 1.18 (95 % CI 1.02, 1.36), p = 0.02 respectively]. In contrast, no significant association was seen for the pooled group or non-severe CAD subgroup (p = NS). Sensitivity analysis showed consistent results.

CONCLUSIONS

IL-10 -1082G/A appears to be associated with early or severe presentation of CAD. Further studies are warranted to confirm this association.

Coronary artery plaque rupture and erosion: Role of wall shear stress profiling and biological patterns in acute coronary syndromes

AIMS

Wall shear stress (WSS) is involved in coronary artery plaque pathological mechanisms and modulation of gene expression. This study aims to provide a comprehensive haemodynamic and biological description of unstable (intact-fibrous-cap, IFC, and ruptured-fibrous-cap, RFC) and stable (chronic coronary syndrome, CCS) plaques and investigate any correlation between WSS and molecular pathways.

METHODS AND RESULTS

We enrolled 24 CCS and 25 Non-ST Elevation Myocardial Infarction-ACS patients with IFC (n = 11) and RFC (n = 14) culprit lesions according to optical coherence tomography analysis. A real-time PCR primer array was performed on peripheral blood mononuclear cells for 17 different molecules whose expression is linked to WSS. Computational fluid dynamics simulations were performed in high-fidelity 3D-coronary artery anatomical models for three patients per group. A total of nine genes were significantly overexpressed in the unstable patients as compared to CCS patients, with no differences between IFC and RFC groups (GPX1, MMP1, MMP9, NOS3, PLA2G7, PI16, SOD1, TIMP1, and TFRC) while four displayed different levels between IFC and RFC groups (TNFα, ADAMTS13, EDN1, and LGALS8). A significantly higher WSS was observed in the RFC group (p < 0.001) compared to the two other groups. A significant correlation was observed between TNFα (p < 0.001), EDN1 (p = 0.036), and MMP9 (p = 0.005) and WSS values in the RFC group.

CONCLUSIONS

Our data demonstrate that IFC and RFC plaques are subject to different WSS conditions and gene expressions, suggesting that WSS profiling may play an essential role in the plaque instability characterization with relevant diagnostic and therapeutic implications in the era of precision medicine.

The Chinese Experience of Imaging in Cardiac Intervention: A Bird's Eye Review

Recent scientific and technological advances have greatly contributed to the development of medical imaging that could enable specific functions. It has become the primary focus of cardiac intervention in preoperative assessment, intraoperative guidance, and postoperative follow-up. This review provides a contemporary overview of the Chinese experience of imaging in cardiac intervention in recent years.

Single-Cell RNA Sequencing of Peripheral Blood Mononuclear Cells From Acute Myocardial Infarction

Background

Acute myocardial infarction (AMI) can occur in patients with atherosclerotic disease, with or without plaque rupture. Previous studies have indicated a set of immune responses to plaque rupture. However, the specific circulating immune cell subsets that mediate inflammatory plaque rupture remain elusive.

Methods

Ten AMI patients were enrolled in our study (five with and five without plaque rupture; plaque characteristics were identified by optical coherence tomography). By single-cell RNA sequencing, we analyzed the transcriptomic profile of peripheral blood mononuclear cells.

Results

We identified 27 cell clusters among 82,550 cells, including monocytes, T cells, NK cells, B cells, megakaryocytes, and CD34⁺ cells. Classical and non-classical monocytes constitute the major inflammatory cell types, and pro-inflammatory genes such as CCL5, TLR7, and CX3CR1 were significantly upregulated in patients with plaque rupture, while the neutrophil activation and degranulation genes FPR2, MMP9, and CLEC4D were significantly expressed in the intermediate monocytes derived from patients without plaque rupture. We also found that CD4⁺ effector T cells may contribute to plaque rupture by producing a range of cytokines and inflammatory-related chemokines, while CD8⁺ effector T cells express more effector molecules in patients without plaque rupture, such as GZMB, GNLY, and PRF1, which may contribute to the progress of plaque erosion. Additionally, NK and B cells played a significant role in activating inflammatory cells and promoting chemokine production in the plaque rupture. Cell–cell communication elaborated characteristics in signaling pathways dominated by inflammatory activation of classical monocytes in patients with plaque rupture.

Conclusions

Our studies demonstrate that the circulating immune cells of patients with plaque rupture exhibit highly pro-inflammatory characteristics, while plaque erosion is mainly associated with intermediate monocyte amplification, neutrophil activation, and degranulation. These findings may provide novel targets for the precise treatment of patients with AMI.

Clinical Presentation and In-Hospital Outcomes of Acute Myocardial Infarction in Young Patients: Japanese Nationwide Registry

Background

Acute myocardial infarction (AMI) in young patients is a concerning issue because of its adverse health and social impacts. Nevertheless, risk factors and prognosis of AMI in young patients are yet to be characterized.

Objectives

This study aimed to characterize AMI in young patients who underwent primary percutaneous coronary intervention (PCI) using large-scale nationwide all-comer registry data in Japan, the Japanese Percutaneous Coronary Intervention (J-PCI).

Methods

This retrospective cohort study evaluated the J-PCI registry data of patients with AMI aged 20 to 79 years who underwent primary PCI between January 2014 and December 2018. Data on risk factor profiles, clinical features, post-procedural complications, and in-hospital outcomes were reviewed.

Results

Among 213,297 patients with AMI who underwent primary PCI, 23,985 (11.2%) were young (ages 20 to 49 years). Compared with the older group (ages 50 to 79 years; n = 189,312), the younger group included a higher number of men, smokers, patients with dyslipidemia, and patients with single-vessel disease, and a lower number of patients with hypertension and diabetes. Despite favorable clinical profiles, younger age was associated with a higher rate of presentation with cardiopulmonary arrest (CPA). Further, concomitant CPA was strongly associated with in-hospital mortality in young patients (odds ratio: 14.2; 95% CI: 9.2 - 21.9).

Conclusions

Younger patients with AMI presented a higher risk of CPA, which was strongly associated with in-hospital mortality. The results of this study highlight the importance of primary AMI prevention strategies in young individuals.

Role of Intracoronary Imaging in Acute Coronary Syndromes

Intravascular imaging with optical coherence tomography (OCT) and intravascular ultrasound provides superior visualization of the culprit plaques for acute coronary syndromes (ACS) compared with coronary angiography. Combined with angiography, intravascular imaging can be used to instigate ‘precision therapy’ for ACS. Post-mortem histopathology identified atherothrombosis at the exposed surface of a ruptured fibrous cap as the main cause of ACS. Further histopathological studies identified intact fibrous caps and calcified nodules as other culprit lesions for ACS. These plaque types were subsequently also identified on intravascular imaging, particularly with the high-resolution OCT. The less-common non-atherothrombotic causes of ACS are coronary artery spasm, coronary artery dissection, and coronary embolism. In this review, the authors provide an overview of clinical studies using intravascular imaging with OCT in the diagnosis and management of ACS.

High-Risk Coronary Plaque Features: A Narrative Review

Advances in coronary plaque imaging over the last few decades have led to an increased interest in the identification of novel high-risk plaque features that are associated with cardiovascular events. Existing practices focus on risk stratification and lipid monitoring for primary and secondary prevention of cardiac events, which is limited by a lack of assessment and treatment of vulnerable plaque. In this review, we summarize the multitude of studies that have identified plaque, haemodynamic and patient factors associated with risk of acute coronary syndrome. Future progress in multi-modal imaging strategies and in our understanding of high-risk plaque features could expand treatment options for coronary disease and improve patient outcomes.

Causes, Angiographic Characteristics, and Management of Premature Myocardial Infarction: JACC State-of-the-Art Review

Among patients presenting with acute myocardial infarction (AMI), the proportion of young individuals has increased in recent years. Although coronary atherosclerosis is less extensive in young patients with AMI, with higher prevalence of single-vessel disease and rare left main involvement, the long-term prognosis is not benign. Young patients with AMI with obstructive coronary artery disease have similar risk factors as older patients except for higher prevalence of smoking, lipid disorders, and family history of premature coronary artery disease, and lower prevalence of diabetes mellitus and hypertension. Smoking cessation is by far the most effective secondary preventive measure. Myocardial infarction with nonobstructive coronary arteries is a relatively common clinical entity (10%-20%) among young patients with AMI, with intravascular and cardiac magnetic resonance imaging being key for diagnosis and potentially treatment. Spontaneous coronary artery dissection is a frequent pathogenetic mechanism of AMI among young women, requiring a high degree of suspicion, especially in the peripartum period.

The Effect of Blood Pressure Variability on Coronary Atherosclerosis Plaques

Hypertension is one of the most important risk factors for coronary heart disease (CHD). The regulation of blood pressure plays a significant role in the development and prognosis of CHD. Blood pressure variability (BPV) refers to the degree of fluctuation of blood pressure over a period of time and is an important indicator of blood pressure stability. Blood pressure fluctuations are complex physiological phenomena, being affected by physiological and pharmacological effects and regulated by behavioral, environmental, hydrodynamic, and neural factors. According to the different time periods for measuring BPV, it can be divided into very short-term, short-term, mid-term, and long-term. Multiple cardiovascular disease animal models and clinical experiments have consistently indicated that abnormal BPV is closely related to coronary events and is a risk factor for CHD independently of average blood pressure. Thrombosis secondary to plaque rupture (PR) or plaque erosion can cause varying blood flow impairment, which is the main pathological basis of CHD. Plaque morphology and composition can influence the clinical outcome, treatment, and prognosis of patients with CHD. Research has shown that PR is more easily induced by hypertension. After adjusting for the traditional factors associated with plaque development, in recent years, some new discoveries have been made on the influence of abnormal BPV on the morphology and composition of coronary plaques and related mechanisms, including inflammation and hemodynamics. This article reviews the impact of BPV on coronary plaques and their related mechanisms, with a view to prevent the occurrence and development of CHD by controlling BPV and to provide new prevention and treatment strategies for the clinical treatment of abnormal blood pressure.

Optical Coherence Tomographic Features of Pancoronary Plaques in Patients With Acute Myocardial Infarction Caused by Layered Plaque Rupture Versus Layered Plaque Erosion

Atherosclerotic plaque instability could occur on the basis of healed plaque which has a layered appearance on optical coherence tomography. This study aimed to investigate pancoronary plaque features of layered plaque rupture (LPR) and layered plaque erosion (LPE) in patients with acute myocardial infarction. Among 388 patients with acute myocardial infarction who underwent preintervention optical coherence tomography imaging of three coronary arteries, 190 patients with layered culprit plaque (49.0%) were identified and further divided into 2 groups: LPR group and LPE group. Clinical characteristics, pancoronary plaque features and clinical outcomes were compared between the 2 groups. Patients with LPR were older, less often male and current smoker, and had a lower coronary flow grade than those with LPE. At the culprit lesion, LPR group had a higher prevalence of lipid plaque, thin-cap fibroatheroma (TCFA), macrophage, and microchannel, and presented with more severe lumen area stenosis than LPE group. At nonculprit lesions, LPR group had a higher prevalence of TCFA and had greater layered tissue thickness and area than LPE group. The ischemia-driven revascularization rate was higher in LPR group. Moreover, we found that TCFA, diameter stenosis >56.5%, and mean lipid arc >179.1° were predictors for layered culprit plaque. In conclusion, patients with LPR had more vulnerable plaque features at culprit and nonculprit lesions and had higher incidence of ischemia-driven revascularization than those with LPE. TCFA, diameter stenosis >56.5%, and mean lipid arc >179.1° were predictors of layered culprit plaque.

ST-Segment Elevation Myocardial Infarction: Sex Differences in Incidence, Etiology, Treatment, and Outcomes

PURPOSE

Although there have been marked improvements in the standard of care for treatment of ST-elevation myocardial infarction, women, especially younger women, continue to have significantly worse outcomes than men.

RECENT FINDINGS

This review highlights the current sex differences in presentation, etiology, treatment, and outcomes among these patients in order to make providers aware of the heterogeneous entities that cause ST-elevation myocardial infarction particularly in women and of disparities in treatment that lead to poorer outcomes in women. Furthermore, it emphasizes evidence-based strategies including standardized protocols for early revascularization, mechanical circulatory support, and access methodology that can reduce sex-based disparities in treatments and outcomes.

TNF-α is a Novel Biomarker for Predicting Plaque Rupture in Patients with ST-Segment Elevation Myocardial Infarction

Background and Aims

Patients with plaque rupture (PR) present with different cardiovascular risks, clinical strategies, and outcomes from those with plaque erosion (PE). However, there are lack of noninvasive biomarkers to distinguish PE from PR.

Methods

A prospective analysis of 382 patients with ST-segment elevation myocardial infarction (STEMI) was conducted. Of these patients, 262 and 120 presented with PR and PE, respectively. An additional 83 patients diagnosed with stable angina pectoris were enrolled as control group. Peripheral blood monocytes were collected pre-percutaneous coronary intervention and used to evaluate the mRNA expression of IL-4, IL-10, IL-1β, and TNF-α in all patients.

Results

STEMI patients had higher IL-4, IL-10, IL-1β, and TNF-α expression than the control patients. The mRNA levels of IL-4, IL-1β, and TNF-α were significantly higher in PR patients than PE; however, no significant difference was observed in IL-10 between PE and PR. The areas under the receiver-operating characteristic curves for IL-4, IL-1β, and TNF-α for PR versus PE were 0.685, 0.747, and 0.895, respectively. At the cut-off value of 2.52, TNF-α demonstrated a sensitivity of 70.61% and specificity of 93.33% for discriminating PR from PE patients. When added to the model of established clinical risk factors, TNF-α significantly improved the predictive accuracy of PR. Multivariable logistic regression analysis indicated that TNF-α mRNA level was independently associated with PR (odds ratio, 3.09; 95% confidence interval, 2.29–4.16; p < 0.001).

Conclusion

The inflammatory response of peripheral blood mononuclear cells in patients with PR was higher than that in patients with PE. TNF-α may be a potential biomarker for predicting PR that could facilitate risk stratification and management in STEMI patients.

Clinical determinants of coronary artery disease burden and vulnerability using optical coherence tomography co-registered with intravascular ultrasound

OBJECTIVES

We investigated clinical determinants of disease burden and vulnerability using optical coherence tomography (OCT) co-registered with intravascular ultrasound (IVUS) in a large cohort of patients.

METHODS

A total of 704 patients [44.5% with acute coronary syndromes (ACS)] underwent coronary intervention. IVUS plaque burden and OCT lipid, macrophage and calcium indices and the presence of thrombus, plaque rupture and thin-cap fibroatheroma (TCFA) were analyzed.

RESULTS

Median patient age was 66 years with 81.8% men, 34.4% with diabetes mellitus and 15.5% with preadmission statins. Median lesion length was 25.7 mm, and 33.0% had a TCFA. Adjusted models indicated (1) older patient age was related to more calcium, but fewer macrophages; (2) men were related to more thrombus with plaque rupture while women had more thrombus without plaque rupture; (3) ACS presentation was related to morphological acute thrombotic events (more thrombus with/without rupture) and plaque vulnerability (more TCFA, more lipid and macrophages and larger plaque burden); (4) diabetes mellitus was related to a greater atherosclerotic disease burden (more lipid and calcium and larger plaque burden) and more thrombus without rupture; (5) hypertension was related to more macrophages; (6) current smoking was related to less calcium; and (7) renal insufficiency and preadmission statin therapy were not independently associated with IVUS or OCT plaque morphology.

CONCLUSION

Patient characteristics, especially diabetes mellitus and aging, affect underlying atherosclerotic burden, among which a greater lipidic burden along with sex differences influence local thrombotic morphology that affects clinical presentation.

Case Report: ST-Elevation Myocardial Infarction Secondary to Acute Atherothrombotic Occlusion Treated With No Stent Strategy

Background

Intravascular imaging plays a vital role in the pathophysiology-based diagnosis and treatment of patients with ST-elevation myocardial infarction (STEMI). We present a case of STEMI due to plaque erosion, which was managed with a no stent approach.

Case Summary

A 43-year-old female with a history of tobacco abuse presented with an anterior STEMI. Coronary angiography revealed acute thrombotic occlusion of the left anterior descending artery with spontaneous recanalization. Intravascular imaging with optical coherence tomography (OCT) demonstrated plaque erosion as the underlying etiology for the acute thrombotic occlusion. A no stent strategy with aspiration thrombectomy and dual antiplatelet therapy was used to manage the patient given that there was no evidence of plaque rupture. Repeat coronary imaging was done at 2 months to assess the status of the lesion.

Conclusion

A 43-year-old female with STEMI due to plaque erosion was successfully managed only by thrombus aspiration and not by angioplasty and stent placement. Individualized treatment approaches in patients with acute coronary syndromes, can not only achieve optimal management goals but also avoid unnecessary complications associated with interventions. This case illustrates how intracoronary imaging and pathophysiology-guided treatment can dramatically change management. In this young patient, STEMI was managed purely by thrombus aspiration. Intravascular imaging obviated the need for stent placement possibly preventing stent-related complications including restenosis and thrombosis.

Ferroptosis: A Potential Target in Cardiovascular Disease

Ferroptosis is a new form of regulatory cell death characterized by iron-dependent and intracellular lipid peroxidation. Ferroptosis can be divided into two stages. The first stage is iron overload in the cell, which generates a large amount of reactive oxygen species through the Fenton reaction, and the second stage results from an imbalance of the intracellular antioxidant system. Excessive phospholipid hydroperoxides cannot be removed by reduction reactions, as this could destroy the cell membrane structure and interfere with mitochondrial function, eventually leading to ferroptosis of the cell. Cardiovascular diseases have gradually become the leading cause of death in modern society. The relationship between ferroptosis and the occurrence and progression of cardiovascular disease has become a research hotspot in recent years. In this review, we summarize the mechanism of ferroptosis and its specific role in cardiovascular disease.

Coexistence of calcified- and lipid-containing plaque components and their association with incidental rupture points in acute coronary syndrome-causing culprit lesions: results from the prospective OPTICO-ACS study

AIMS

Rupture of the fibrous cap (RFC) represents the main pathophysiological mechanism causing acute coronary syndromes (ACS). Destabilization due to plaque biomechanics is considered to be importantly involved, exact mechanisms triggering plaque ruptures are, however, unknown. This study aims at characterizing the relation between plaque components and rupture points at ACS-causing culprit lesions in a large cohort of ACS-patients assessed by high-resolution intracoronary imaging.

METHODS AND RESULTS

Within the prospective, multicentric OPTICO-ACS study program, the ACS-causing culprit plaques of 282 consecutive patients were investigated following a standardized optical coherence tomography (OCT) imaging protocol. Each pullback was assessed on a frame-by-frame basis for the presence of lipid components (LC), calcium components (CC), and coexistence of both LC and CC (LCC) by two independent OCT-core labs. Of the 282 ACS-patients, 204 patients (72.3%) presented with ACS caused by culprit lesions with rupture of the fibrous cap (RFC-ACS) and 27.7% patients had ACS caused by culprit lesions with intact fibrous cap (IFC-ACS). When comparing RFC-ACS to IFC-ACS, a preferential occurrence of all three plaque components (LC, CC, and LCC) in RFC-ACS became apparent (P < 0.001). Within ruptured culprit lesions, the zone straight at the rupture point [extended rupture zone (RZ)] was characterized by similar (24.7% vs. 24.0%; P = ns) calcium content when compared with the proximal and distal border of the culprit lesion [border zone (BZ)]. The RZ displayed a significantly higher amount of both, LC (100% vs. 69.8%; P < 0.001) and LCC (22.7% vs. 6.8%; P < 0.001), when compared with the BZ. The relative component increase towards the RZ was particularly evident for LCC (+233.8%), while LC showed only a modest increase (+43.3%).

CONCLUSIONS

Calcified- and lipid-containing components characterize ruptured fibrous cap ACS-causing culprit lesions. Their coexistence is accelerated directly at the ruptured point, suggesting a pathophysiological contribution in the development of RFC-ACS.

[Intracoronary imaging - how plaque morphology impacts personal medical therapy]

Even with emerging evidence that the use of intracoronary imaging techniques can significantly support the interventional procedure, the use of intracoronary imaging during catheterization procedures still remains comparatively low. With the help of intracoronary imaging percutaneous coronary interventions can be optimized and fundamental information about the plaque morphology can be archived. This is not only beneficial in determining plaque vulnerability but can also assist in the interventional approach of complex lesions including calcified lesions, as well as lesions causing an acute coronary syndrome. Especially in the context of the latter, identification of the underlying entity may provide alternative personalized approaches for patients with acute coronary syndrome.

Distinct pathological mechanisms distinguish acute coronary syndrome caused by plaque erosion from plaque rupture

PURPOSE OF REVIEW

The current systematic review aims to provide novel insights into the distinct pathological features of acute coronary syndrome (ACS) with intact fibrous cap, also known as 'plaque erosion'. A more detailed understanding of its underlying pathomechanisms provides the basis for future personalized therapeutic approaches to ACS.

RECENT FINDINGS

In the past years, a mounting proportion of evidence point towards the concept of plaque erosion being responsible for more than one-third of all cases of ACS and representing an autonomous ACS-causing entity driven by biomechanical forces, immunological alternations and systemic elevation of inflammatory mediators. First pilot studies proved a therapeutic paradigm shift from primary PCI at the ACS-causing culprit lesion to systemic therapies in patients with ACS caused by plaque erosion.

SUMMARY

This review provides the current status of the broad basic and clinical studies focused to the topic of plaque erosion: a new ACS-causing pathophysiology with different pathological aspects providing appropriate implications for personalized therapies in ACS.

Plaque Erosion: A Distinctive Pathological Mechanism of Acute Coronary Syndrome

Plaque erosion (PE) is one of the most important pathological mechanisms underlying acute coronary syndrome (ACS). The incidence of PE is being increasingly recognized owing to the development and popularization of intracavitary imaging. Unlike traditional vulnerable plaques, eroded plaques have unique pathological characteristics. Moreover, recent studies have revealed that there are differences in the physiopathological mechanisms, biomarkers, and clinical outcomes between PE and plaque rupture (PR). Accurate diagnosis and treatment of eroded plaques require an understanding of the pathogenesis of PE. In this review, we summarize recent scientific discoveries of the pathological characteristics, mechanisms, biomarkers, clinical strategies, and prognosis in patients with PE.

IRGM/Irgm1 facilitates macrophage apoptosis through ROS generation and MAPK signal transduction: Irgm1 +/- mice display increases atherosclerotic plaque stability

Rationale: Atherosclerosis plaque rupture (PR) is the pathological basis and chief culprit of most acute cardiovascular events and death. Given the complex and important role of macrophage apoptosis and autophagy in affecting plaque stability, an important unanswered question include is whether, and how, immunity-related GTPase family M protein (IRGM) and its mouse orthologue IRGM1 affect macrophage survival and atherosclerotic plaque stability.

Methods: To investigate whether serum IRGM of ST-segment elevation myocardial infarction (STEMI) patients is related to plaque morphology, we divided 85 STEMI patients into those with and without plaque rupture (PR and non-PR, respectively) based on OCT image analysis, and quantified the patients' serum IRGM levels. Next, we engineered Irgm1 deficient mice (Irgm1^+/-) and chimera mice with Irgm1 deficiency in the bone marrow on an ApoE^-/- background, which were then fed a high-fat diet for 16 weeks. Pathological staining was used to detect necrotic plaque cores, ratios of neutral lipids and cholesterol crystal, as well as collagen fiber contents in these mice to characterize plaque stability. In addition, immunofluorescence, immunohistochemical staining and western blot were used to detect the apoptosis of macrophages in the plaques. In vitro, THP-1 and RAW264.7 cells were stimulated with ox-LDL to mimic the in vivo environment, and IRGM/IRGM1 expression were modified by specific siRNA (knockdown) or IRGM plasmid (knocked-in). The effect of IRGM/Irgm1 on autophagy and apoptosis of macrophages induced by ox-LDL was then evaluated. In addition, we introduced inhibitors of the JNK/p38/ERK signaling pathway to verify the specific mechanism by which Irgm1 regulates RAW264.7 cell apoptosis.

Results: The serum IRGM levels of PR patients is significantly higher than that of non-PR patients and healthy volunteers, which may be an effective predictor of PR. On a high-fat diet, Irgm1-deficient mice exhibit reduced necrotic plaque cores, as well as neutral lipid and cholesterol crystal ratios, with increased collagen fiber content. Additionally, macrophage apoptosis is inhibited in the plaques of Irgm1-deficient mice. In vitro, IRGM/Irgm1 deficiency rapidly inhibits ox-LDL-induced macrophage autophagy while inhibiting ox-LDL-induced macrophage apoptosis in late stages. Additionally, IRGM/Irgm1 deficiency suppresses reactive oxygen species (ROS) production in macrophages, while removal of ROS effectively inhibits macrophage apoptosis induced by IRGM overexpression. We further show that Irgm1 can affect macrophage apoptosis by regulating JNK/p38/ERK phosphorylation in the MAPK signaling pathway.

Conclusions: Serum IRGM may be related to the process of PR in STEMI patients, and IRGM/Irgm1 deficiency increases plaque stability. In addition, IRGM/Irgm1 deficiency suppresses macrophage apoptosis by inhibiting ROS generation and MAPK signaling transduction. Cumulatively, these results suggest that targeting IRGM may represent a new treatment strategy for the prevention and treatment of acute cardiovascular deaths caused by PR.

Age and Phenotype of Patients With Plaque Erosion

Background

A recent study reported that the outcome of patients with plaque erosion treated with stenting is poor when the underlying plaque is lipid rich. However, the detailed phenotype of patients with plaque erosion, particularly as related to different age groups, has not been systematically studied.

Methods and Results

Patients with acute coronary syndromes caused by plaque erosion were selected from 2 data sets. Demographic, clinical, angiographic, and optical coherence tomography findings of the culprit lesion were compared between 5 age groups. Among 579 erosion patients, male sex and current smoking were less frequent, and hypertension, diabetes, and chronic kidney disease were more frequent in older patients. ST‐segment–elevation myocardial infarction was more frequent in younger patients. Percentage of diameter stenosis on angiogram was greater in older patients. The prevalence of lipid‐rich plaque (27.3% in age <45 years and 49.4% in age ≥75 years, P<0.001), cholesterol crystal (3.9% in age <45 years and 21.8% in age ≥75 years, P=0.027), and calcification (5.5% in age <45 years and 54.0% in age ≥75 years, P<0.001) increased with age. After adjusting risk factors, younger patients were associated with the presence of thrombus, and older patients were associated with greater percentage of diameter stenosis and the presence of lipid‐rich plaque and calcification.

Conclusions

The demographic, clinical, angiographic, and plaque phenotypes of patients with plaque erosion distinctly vary depending on age. This may affect the clinical outcome in these patients.

Registration

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT03479723, NCT02041650.

Plaque erosion and acute coronary syndromes: phenotype, molecular characteristics and future directions

Although acute coronary syndromes (ACS) remain one of the leading causes of death, the clinical presentation has changed over the past three decades with a decline in the incidence of ST-segment elevation myocardial infarction (STEMI) and an increase in non-STEMI. This epidemiological shift is at least partially explained by changes in plaque biology as a result of the widespread use of statins. Historically, atherosclerotic plaque rupture of the fibrous cap was thought to be the main culprit in ACS. However, plaque erosion with an intact fibrous cap is now responsible for about one third of ACS and up to two thirds of non-STEMI. Two major research approaches have enabled a better understanding of plaque erosion. First, advanced intravascular imaging has provided opportunities for an 'optical biopsy' and extensive phenotyping of coronary plaques in living patients. Second, basic science experiments have shed light on the unique molecular characteristics of plaque erosion. At present, patients with ACS are still uniformly treated with coronary stents irrespective of the underlying pathobiology. However, pilot studies indicate that patients with plaque erosion might be treated conservatively without coronary stenting. In this Review, we discuss the patient phenotype and the molecular characteristics in atherosclerotic plaque erosion and provide our vision for a potential major shift in the management of patients with plaque erosion.

Focal Geometry and Characteristics of Erosion-Prone Coronary Plaques in vivo Angiography and Optical Coherence Tomography Study

Objective: This study compared focal geometry and characteristics of culprit plaque erosion (PE) vs. non-culprit plaques in ST-segment elevated myocardial infarction (STEMI) patients in whom optical coherence tomography (OCT) identified PE as the cause of the acute event.

Background: Culprit PE is a distinct clinical entity with specific coronary risk factors and its own tailored management strategy. However, not all plaques develop erosion resulting in occlusive thrombus formation.

Methods: Between January 2017 and July 2019, there were 484 STEMI patients in whom OCT at the time of primary percutaneous intervention identified culprit lesion PE to be the cause of the event; 484 culprit PE were compared to 1,132 non-culprit plaques within 1,196 imaged vessels.

Results: Culprit PE were highly populated at “hot spots” within the proximal 40 mm in the left anterior descending artery (LAD) and tended to cluster proximal to a nearby bifurcation mainly in the LAD. Minimal lumen area (MLA) <2.51 mm² and AS (area stenosis) >64.02% discriminated culprit PE from non-culprit plaques. In the multivariable analysis, focal geometry (LAD location, distance from coronary ostium <40 mm, and location proximal to a nearby bifurcation), luminal narrowing (MLA <2.51 mm², AS > 64.02%), and TCFA phenotype were independent predictors of culprit PE overall. Cholesterol crystals were predictive of culprit PE with underlying LRP morphology while the absence of calcification and microchannels were risk factors for culprit PE with an underlying non-LRP. Similarities and differences in predictors of culprit PE were found between males and females; distance from coronary ostium <40 mm, MLA <2.51 mm², TCFA, and less spotty calcium were risk factors of culprit PE in males, but not in females while smaller RVD was associated with culprit PE only in females.

Conclusions: Irrespective of underlying lesion substrates and patient risk factors, there are lesion-specific and OCT-identifiable predictors of developing culprit PE in erosion-prone vulnerable patients.

Predictors of Coronary Plaque Erosion in Current and Non-Current Smokers With ST-Segment Elevation Myocardial Infarction - An Optical Coherence Tomography Study

BACKGROUND

Smoking is an important risk factor of plaque erosion. This study aimed to investigate the predictors of plaque erosion in current and non-current smokers presenting with ST-segment elevation myocardial infarction (STEMI).Methods and Results:A total of 1,320 STEMI patients with culprit plaque rupture or plaque erosion detected by pre-intervention optical coherence tomography were divided into a current smoking group (n=715) and non-current smoking group (n=605). Plaque erosion accounted for 30.8% (220/715) of culprit lesions in the current smokers and 21.2% (128/605) in the non-current smokers. Multivariable analysis showed age <50 years, single-vessel disease and the absence of dyslipidemia were independently associated with plaque erosion rather than plaque rupture, regardless of smoking status. In current smokers, diabetes mellitus (odds ratio [OR]: 0.29; 95% confidence interval [CI]: 0.10-0.83; P=0.021) was negatively associated with plaque erosion as compared with plaque rupture. In non-current smokers, minimal lumen area (MLA, OR: 1.37; 95% CI: 1.16-1.62; P<0.001) and nearby bifurcation (OR: 3.20; 95% CI: 1.98-5.16; P<0.001) were positively related to plaque erosion, but not plaque rupture.

CONCLUSIONS

In patients with STEMI, the presence of diabetes mellitus significantly increased the risk of rupture-based STEMI but may not have reduced the risk of plaque erosion-based STEMI in current smokers. Nearby bifurcation and larger MLA were associated with plaque erosion in non-current smokers.

Optical Coherence Tomography of Plaque Erosion: JACC Focus Seminar Part 2/3

Plaque erosion, a distinct histopathological and clinical entity, accounts for over 30% of acute coronary syndromes (ACS). Optical coherence tomography allows in vivo diagnosis of plaque erosion. Local flow perturbation with activation of Toll-like receptor 2 and CD8⁺ T cells and subsequent desquamation of endothelium and neutrophil extracellular trap formation contribute to mechanisms of plaque erosion. Compared with ACS patients with plaque rupture, those with plaque erosion are younger, have fewer traditional cardiovascular risk factors, have lower plaque burden, and are more likely to present with non-ST-segment elevation ACS. Early evidence suggests that in patients with ACS caused by plaque erosion, antithrombotic therapy without stenting may be a safe and effective option. Future randomized trials are needed to validate these findings. Clinical studies to develop noninvasive point-of-care biomarkers that distinguish plaque rupture from erosion, and to test novel therapies that target molecular pathways involved in plaque erosion are needed.

Association between apolipoprotein B/A1 ratio and coronary plaque vulnerability in patients with atherosclerotic cardiovascular disease: an intravascular optical coherence tomography study

Background

Apolipoprotein (Apo) A1 and Apo B are strongly associated with the risk of atherosclerotic cardiovascular disease (ASCVD). However, the relationship between the Apo B/A1 ratio and the morphology of coronary vulnerable plaques has not been fully elucidated in patients with ASCVD.

Methods

A total of 320 patients with ASCVD undergoing percutaneous coronary intervention were enrolled and assigned into acute coronary syndrome (ACS) or chronic coronary syndrome (CCS) group. The morphology of culprit plaque was analyzed by intravascular optical coherence tomography. Association between the Apo B/A1 ratio and coronary vulnerable plaques were evaluated using logistic regression models and receiver operator characteristic (ROC) curve analyses.

Results

The Apo B/A1 ratio was higher in ACS patients than CCS patients (0.77 ± 0.28 vs. 0.64 ± 0.22, P < 0.001) and it was also higher in patients with plaque rupture, erosion or thrombus than those without culprit plaques. The high Apo B/A1 ratio was associated with high percent of vulnerable plaques compared with low ratio group. The Apo B/A1 ratio was negatively related to fibrous cap thickness in lipid-rich plaque (r = − 0.228, P = 0.043). Univariate and multivariate logistic regression analyses revealed that the Apo B/A1 ratio was an independent factor of plaque rupture, erosion, and thrombus. The area under the ROC curve of the Apo B/A1 ratio for plaque rupture, erosion, and thrombus were 0.632, 0.624, and 0.670 respectively (P < 0.001 for all), which were higher than that of low-density lipoprotein cholesterol.

Conclusions

The Apo B/A1 ratio is an independent predictor for plaque rupture, erosion, and thrombus in patients with ASCVD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01381-9.

Successful optical coherence tomography-guided treatment in a 19-year-old patient with ST-segment elevation myocardial infarction caused by plaque erosion

ST-segment elevation myocardial infarction is a type of coronary atherosclerotic heart disease, and its pathophysiological mechanism is formation of lipid plaques. We report a 19-year-old patient with ST-segment elevation myocardial infarction caused by plaque erosion, but he did not have any common traditional risk factors of lipid plaques. His treatment was guided by optical coherence tomography. He received successful treatment and had a good prognosis. Optical coherence tomography can be used to help understand the pathogenesis of myocardial infarction and visualize the real lumen.

Predictors of non-stenting strategy for acute coronary syndrome caused by plaque erosion: four-year outcomes of the EROSION study

BACKGROUND

The EROSION study demonstrated that patients with an acute coronary syndrome (ACS) caused by plaque erosion could be treated with antithrombotic therapy without stenting. However, the long-term prognosis of this strategy is still unclear.

AIMS

The aim of this study was to test whether a non-stenting antithrombotic strategy was still effective at four-year follow-up and to explore potential predictors of long-term prognosis.

METHODS

This study was a long-term follow-up of the EROSION study. Follow-up was conducted by phone call or clinical visit. Patients were divided into two groups - those with target lesion revascularisation (the TLR group), and the non-TLR group.

RESULTS

Out of 55 patients who completed one-month follow-up, 52 patients finished four-year follow-up. The median duration was 4.8 years (range, 4.2-5.8 years). The majority of patients remained free from events, and all patients were free from hard endpoints (death, myocardial infarction, stroke, bypass surgery, or heart failure). Only one patient had gastrointestinal bleeding, and 11 patients underwent TLR. Patients in the non-TLR group had more optical coherence tomography (OCT) thrombus reduction from baseline to one month; 95% of patients in the non-TLR group versus 45% in the TLR group (p=0.001) met the primary endpoint (thrombus volume reduction >50%). Angiographic results showed that the TLR group had less improvement in diameter stenosis (p=0.014) at one month compared with the non-TLR group.

CONCLUSIONS

Four-year follow-up findings reconfirmed the safety of an antithrombotic therapy without stenting for ACS caused by erosion. Patients with better response to antithrombotic therapy in the first month were less likely to require stent implantation during the next four years.

Comparison of Outcomes of Coronary Artery Disease Treated by Percutaneous Coronary Intervention in 3 Different Age Groups (<45, 46-65, and >65 Years)

There is paucity of data examining long-term outcomes of premature coronary artery disease (CAD). We aimed to investigate the short- and long-term clinical outcomes of patients with premature CAD treated by percutaneous coronary intervention (PCI) compared to older cohorts. We analyzed data from 27,869 patients who underwent PCI from 2005-2017 enrolled in a multicenter PCI registry. Patients were divided into three age groups: young group (≤ 45 years), middle-age group (46-65 years) and older group (>65 years). There were higher rates of current smokers in the young (n = 1,711) compared to the middle-age (n = 12,830) and older groups (n = 13,328) (54.2% vs 34.6% vs 11%) and the young presented more frequently with acute coronary syndrome (ACS) (78% vs 66% vs 62%), all p <0.05. There were also greater rates of cardiogenic shock (CS), out-of-hospital cardiac arrest (OHCA) and ST-elevation myocardial infarction (STEMI) in the young, all p <0.05. The young cohort with STEMI had higher rates of in-hospital, 30-day death, and long-term mortality (3.8% vs 0.2%, 4.3% vs 0.2% and 8.6% vs 3.1%, all p <0.05, respectively) compared to the non-STEMI subgroup. There was a stepwise increase in long-term mortality from the young, to middle-age, to the older group (6.1% vs 9.9% vs 26.8%, p <0.001). Younger age was an independent predictor of lower long-term mortality (HR 0.66, 95% CI 0.52-0.84, p = 0.001). In conclusion, younger patients presenting with STEMI had worse prognosis compared to those presenting with non-STEMI. Despite higher risk presentations among young patients, their overall prognosis was favorable compared to older age groups.