Effective anti-thrombotic therapy without stenting: intravascular optical coherence tomography-based management in plaque erosion (the EROSION study)

"Very" Very Late Stent Thrombosis: The Occurrence of Thrombosis 12.3 Years After Paclitaxel-Eluting Stent Implantation

Very late stent thrombosis (VLST) refers to stent thrombosis occurring beyond one year after coronary intervention. "Very" very or extremely late stent thrombosis (VVLST), occurring after five years of drug-eluting stent (DES) implantation, is extremely rare. We report a case of a 60-year-old male patient with ST-elevation myocardial infarction (STEMI) due to in-stent thrombosis 12.3 years after first-generation DES implantation; we also engage in a brief discussion of its pathogenesis and prevention.

Machine Learning in Invasive and Noninvasive Coronary Angiography

PURPOSE OF REVIEW

The objective of this review is to shed light on the transformative potential of machine learning (ML) in coronary angiography. We aim to understand existing developments in using ML for coronary angiography and discuss broader implications for the future of coronary angiography and cardiovascular medicine.

RECENT FINDINGS

The developments in invasive and noninvasive imaging have revolutionized diagnosis and treatment of coronary artery disease (CAD). However, CAD remains underdiagnosed and undertreated. ML has emerged as a powerful tool to further improve image analysis, hemodynamic assessment, lesion detection, and predictive modeling. These advancements have enabled more accurate identification of CAD, streamlined workflows, reduced the need for invasive diagnostic procedures, and improved the diagnostic value of invasive procedures when they are needed. Further integration of ML with coronary angiography will advance the prevention, diagnosis, and treatment of CAD. The integration of ML with coronary angiography is ushering in a new era in cardiovascular medicine. We highlight five use cases to leverage ML in coronary angiography: (1) improvement of quality and efficacy, (2) characterization of plaque, (3) hemodynamic assessment, (4) prediction of future outcomes, and (5) diagnosis of non-atherosclerotic coronary disease.

Neutrophil extracellular trap burden correlates with the stenosis of coronary atherosclerosis

Background

Coronary atherosclerosis diseases (CADs) are associated with chronic inflammation. Neutrophil extracellular traps (NETs) are a type of novel proinflammatory cytokines whose levels are dramatically elevated in acute coronary syndrome. We conducted this study to further evaluate the association between circulating NET-associated markers and CAD in Chinese adults.

Methods

A total of 174 patients with CAD and 55 healthy controls were screened using percutaneous coronary intervention or coronary computed tomography angiography. Blood lipid levels, blood glucose levels, and blood cell counts were determined using commercial kits. Serum levels of myeloperoxidase (MPO) and neutrophil elastase (NE) were measured using ELISA. Double-stranded DNA (dsDNA) in serum was quantified using the Quant-iT PicoGreen assay. We also compared the circulating NET levels with various parameters in the study subjects.

Results

The levels of serum NET markers, dsDNA, MPO, and NE, were significantly elevated in patients with CAD, particularly in the severe group, consistent with the increase in neutrophil counts. The levels of NET markers correlated with the risk factors of AS, increasing with the number of risk factors. NET markers were identified as independent risk factors for severe coronary stenosis and also as predictors of severe CAD.

Conclusion

NETs may be related to AS and serve as indicators or predictors of stenosis in patients with severe CAD.

Identification of Optical Coherence Tomography-Defined Coronary Plaque Erosion by Preprocedural Computed Tomography Angiography

Background A previous coronary computed tomography (CT) angiographic study failed to discriminate optical coherence tomography-defined intact fibrous cap culprit lesions (IFC group) from those with ruptured fibrous caps (RFC group) in patients with coronary artery disease. This study aimed to evaluate the diagnostic efficacy of preprocedural coronary CT imaging in identifying subsequently performed optical coherence tomography-defined plaque rupture or erosion at culprit lesions in patients with non-ST-segment-elevation acute myocardial infarction. Methods and Results This study used data from 2 recently published studies that tested the hypothesis that coronary CT angiography (CCTA) before percutaneous coronary intervention may provide diagnostic information on the high-risk atherosclerotic burden in patients with non-ST-segment-elevation acute myocardial infarction. In the analysis of 186 patients, optical coherence tomography identified 106 RFC plaques and 80 IFC plaques as the culprit lesions. On CT, the prevalence of low-attenuation plaque, positive remodeling, napkin-ring sign, and spotty calcification were all significantly lower in the IFC group. The culprit vessel pericoronary adipose tissue inflammation and coronary artery calcium scores were significantly lower in the IFC group than in the RFC group. The absence of low-attenuation plaque, napkin-ring sign, zero coronary artery calcium, and low pericoronary adipose tissue inflammation were independent predictors of IFC. When stratified into 5 subgroups according to the number of these 4 CT factors, the prevalence of IFC was 8.3%, 20.8%, 44.6%, 75.6%, and 100% (P<0.001), respectively. Conclusions Preprocedural comprehensive coronary CT imaging, including coronary artery calcium and pericoronary adipose tissue inflammation assessment, can accurately and noninvasively identify optical coherence tomography-defined IFC or RFC culprit lesions.

Advances in Intravascular Ultrasound

Since its inception, intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have played a significant role in evaluating the pathophysiology of coronary artery disease (CAD) guiding the interventional and medical management of CAD improving outcomes in patients. Although the benefits of each of these modalities have been proven, due to some limitations, no single intravascular imaging technique has been proven to provide a detailed and complete evaluation of all CAD lesions. The use of different intravascular imaging modalities sequentially may lead to complications, which are cumbersome, consume time, and add financial burden to the patient. Recently, hybrid imaging catheters that combine OCT and IVUS benefits have been developed to limit these problems. Intravascular imaging techniques we are using currently have some drawbacks that hinder accurate assessment of plaque morphology and pathobiology as demonstrated in many histological studies, causing difficulty in identifying high-risk plaques. To overcome these limitations, great efforts have been put into developing hybrid, dual-probe catheters by combining imaging modalities to get an accurate analysis of plaque characteristics, and high-risk lesions. At present, many dual-probe catheters are available including combined IVUS-OCT, near-infrared spectroscopy-IVUS that is available commercially, the OCT-near infrared fluorescence (NIRF) molecular imaging, IVUS-NIRF, and combined fluorescence lifetime-IVUS imaging. Application of this combined multimodal imaging in clinical practice overcomes the limitations of standalone imaging and helps in providing a comprehensive and accurate visualization of plaque characteristics, composition, and plaque biology. The present article summarizes the advances in hybrid intravascular imaging, analyses the technical hindrances that should be known to have a use in the different clinical circumstances, and the till date shreds of evidence available from their first clinical application aiming to bring these modalities into the limelight and their potential role in the study of CAD.

Intravascular Imaging for Guiding In-Stent Restenosis and Stent Thrombosis Therapy

Advances in stent technology and the design of endovascular devices with thinner struts, anti-inflammatory and antithrombotic polymers, and better drug kinetics have enhanced the safety and efficacy of the second-generation drug-eluting stents and broadened their use in the therapy of high-risk patients and complex anatomies. However, despite these developments, in-stent restenosis and stent thrombosis remain the Achilles' heel of percutaneous coronary intervention, with their cumulative incidence reaching up to 10% at 5 years following percutaneous coronary intervention. The treatment of stent failure poses challenges and is associated with a worse prognosis than conventional percutaneous coronary intervention. Several studies have recently highlighted the value of intravascular imaging in identifying causes of stent failure, underscored its role in treatment planning, and registries have shown that its use may be associated with better clinical outcomes. The present review aims to summarize the evidence in the field; it discusses the value of intravascular imaging in identifying the mechanisms of in-stent restenosis and stent thrombosis in assessing the morphological characteristics of neointima tissue that appears to determine long-term outcomes in evaluating procedural results, and presents the findings of studies supporting its value in guiding therapy in stent failure.

Intracoronary Imaging of Vulnerable Plaque-From Clinical Research to Everyday Practice

The introduction into clinical practice of intravascular imaging, including intravascular ultrasound (IVUS), optical coherence tomography (OCT) and their derivatives, allowed for the in vivo assessment of coronary atherosclerosis in humans, including insights into plaque evolution and progression process. Intravascular ultrasound, the most commonly used intravascular modality in many countries, due to its low resolution cannot assess many features of vulnerable plaque such as lipid plaque or thin-cap fibroatheroma. Thus, novel methods were introduced to facilitate this problem including virtual histology intravascular ultrasound and later on near-infrared spectroscopy and OCT. Howbeit, none of the currently used modalities can assess all known characteristics of plaque vulnerability; hence, the idea of combining different intravascular imaging methods has emerged including NIRS-IVUS or OCT-IVUS imaging. All of those described methods may allow us to identify the most vulnerable plaques, which are prone to cause acute coronary syndrome, and thus they may allow us to introduce proper treatment before plaque destabilization.

Culprit Lesion Morphology of Rapidly Progressive and Extensive Anterior-Wall ST-Segment Elevation Myocardial Infarction

BACKGROUND

Rapidly progressive, extensive myocardial injury/infarction (RPEMI) beyond the concept of wave-front phenomenon can be observed even when achieving timely reperfusion; however, the pathogenesis of RPEMI remains unknown. This retrospective study investigated clinical and lesion characteristics of RPEMI, focusing on culprit-lesion morphology (CLM).

METHODS

Among patients with extensive anterior-wall ST-segment elevation myocardial infarction due to proximal left anterior descending artery lesions who had reperfusion within 3 hours of symptom onset, 60 patients undergoing both intravascular ultrasound and cardiac magnetic resonance imaging were enrolled. Myocardial injury/infarction before reperfusion therapy was assessed by QRS scores at hospitalization electrocardiogram, and the extent of myocardial injury/infarction was evaluated by cardiac magnetic resonance imaging, which measured area at risk, infarct size, myocardial salvage index, microvascular obstruction, and left ventricular ejection fraction. RPEMI was defined as lower left ventricular ejection fraction (less median value) with microvascular obstruction.

RESULTS

Despite comparable onset-to-door and onset-to-reperfusion times and area at risk, patients with RPEMI showed higher QRS scores at hospitalization (5 [4.3-6] versus 3 [2-4], P<0.001) and infarct size (26.5±9.1 versus 20.4±10.5%, P=0.04), and a tendency toward lower myocardial salvage index (0.27±0.14 versus 0.36±0.20, P=0.10) compared with those without. Patients with versus without RPEMI more frequently observed specific CLM on intravascular ultrasound, characterized by the combination of vulnerable plaques, plaque ruptures, and/or large thrombi. When stratified by CLM-score composed of these 3 criteria, higher CLM-scores were or tended to be associated with higher QRS scores and incidence of RPEMI. In multivariate analyses including no-reflow phenomenon and final coronary-flow deterioration, increased CLM-score (≥2) was independently associated with high QRS scores and RPEMI (odd ratio 11.25 [95% CI, 2.43-52.00]; P=0.002).

CONCLUSIONS

Vulnerable CLM was a consistent determinant of advanced myocardial injury/infarction both before and after reperfusion therapy and may play a pivotal role in the development of RPEMI.

Optical coherence tomography in coronary atherosclerosis assessment and intervention

Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing with the rapid progression of atherosclerosis. Accurate detection by OCT of sequelae from percutaneous coronary interventions that might be missed by angiography could improve clinical outcomes. In addition, OCT has become an essential diagnostic modality for myocardial infarction with non-obstructive coronary arteries. Insight into neoatherosclerosis from OCT could improve our understanding of the mechanisms of very late stent thrombosis. The appropriate use of OCT depends on accurate interpretation and understanding of the clinical significance of OCT findings. In this Review, we summarize the state of the art in cardiac OCT and facilitate the uniform use of this modality in coronary atherosclerosis. Contributions have been made by clinicians and investigators worldwide with extensive experience in OCT, with the aim that this document will serve as a standard reference for future research and clinical application.

Soluble ST2 in coronary artery disease: Clinical biomarkers and treatment guidance

The IL-33/ST2 L signaling pathway is involved in the pathophysiological processes of several diseases and mainly exerts anti-inflammatory and antifibrotic effects. Soluble suppression of tumorigenicity 2 (sST2), which serves as a competitive inhibitory molecule of this pathway, is a member of the interleukin (IL)-1 family, a decoy receptor for IL33, thought to play a role in cardiac remodeling and the inflammatory process. However, the association between sST2 and coronary artery disease (CAD), one of the most common causes of heart failure, is still being explored. We therefore reviewed the research on sST2 in the field of CAD, including reflecting the atherosclerosis burden, predicting no-reflow, predicting prognosis, responding to myocardial remodeling, and guiding management, hoping to provide cardiologists with new perspectives.

Sex differences at the platelet-vascular interface

Platelets are multifunctional cells that ensure the integrity of the vascular wall and modulate the immune response at the blood/vascular interface. Their pathological activation results in both thrombosis and inflammation and implicates them in the pathogenesis of vascular disease. Vascular diseases are sexually dimorphic in terms of incidence, clinical presentation, outcome, and efficacy of anti-platelet therapy. We here provide an overview of what is known about the role of platelets in the initiation and progression of vascular diseases and summarize what is known about the sex differences in platelet reactivity and in the thromboinflammatory mechanisms that drive these diseases, with a particular focus on atherosclerosis, obstructive and non-obstructive coronary artery disease, and ischemic stroke. Understanding the sex differences at the platelet-vascular interface is clinically relevant as it will enable: (1) to design new therapeutic strategies that prevent the detrimental effects of the immune-modulatory function of platelets taking sex into account, and (2) to evaluate if sex-specific anti-platelet drug regimens should be used to reduce the risk not only of thrombosis but also of vascular disease progression.

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.

In vivo detection of plaque erosion by intravascular optical coherence tomography using artificial intelligence

Plaque erosion is one of the most common underlying mechanisms for acute coronary syndrome (ACS). Optical coherence tomography (OCT) allows in vivo diagnosis of plaque erosion. However, challenge remains due to high inter- and intra-observer variability. We developed an artificial intelligence method based on deep learning for fully automated detection of plaque erosion in vivo, which achieved a recall of 0.800 ± 0.175, a precision of 0.734 ± 0.254, and an area under the precision-recall curve (AUC) of 0.707. Our proposed method is in good agreement with physicians, and can help improve the clinical diagnosis of plaque erosion and develop individualized treatment strategies for optimal management of ACS patients.

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.

Feasibility and Safety of Very-Low Contrast Combined Ringer's Solution in Optical Coherence Tomography Imaging

Background

Optical coherence tomography (OCT) is an important modality used in coronary intervention. However, OCT requires a high amount of contrast media, limiting its extensive application in clinical practice. This study compared OCT images of coronary lesions obtained using contrast media and very-low contrast combined Ringer's solution (VLCCR) in patients with acute coronary syndrome (ACS).

Methods

Thirty ACS patients with a total of 36 native lesions and stenoses from 70 to 90% were included in this study. Two kinds of flushing media (a contrast medium and VLCCR) were used in succession in a random order for OCT image pullback of each lesion. VLCCR method is using low volume contrast (4–5 ml) injected into the guiding catheter previously combination with injector infused Ringer's solution instead of pure contrast medium. The safety of procedure was evaluated by recording the patients ‘symptoms, changes of ECG, blood pressure and heart rate. OCT images were analyzed to determine the image clarity. Lumen area and diameter were also measured and the consistency between the two media was compared.

Results

OCT procedure using either contrast or VLCCR did not show any peri-procedural adverse events. There was no difference in changes of blood pressure and heart rate in both procedures, however, VLCCR procedure showed less procedure-related symptoms and ECG changes. We found that the percentage of clear image frame was equivalent between the contrast and VLCCR media (98.0 vs. 96.9%, P = 0.90). We also observed a high degree of similarity between the different lesion phenotypes of ACS for both media. There was a linear correlation of the phenotypes obtained with these two different methods, and a significant correlation was observed between measurements obtained with contrast and VLCCR without correction for the refractive index of VLCCR (correlation coefficients ranged between 0.829 and 0.948).

Conclusions

OCT imaging using VLCCR for blood clearance is feasible and safe and provides similar imaging quality compared to OCT imaging obtained using radiographic contrast media for ACS patients.

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.

The Role of Antiplatelet Therapy in Patients With MINOCA

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous group of clinical entities characterized by the common clinical evidence of myocardial infarction (MI) with non-obstructive coronary arteries on coronary angiography and without an overt cause for the MI. Platelets play a cornerstone role in the pathophysiology of MI with obstructive coronary arteries. Accordingly, antiplatelet therapy is recommended for treating patients with MI and obstructive coronary disease. However, the role of platelets in the pathophysiology of MINOCA patients is not fully defined, questioning the role of antiplatelet therapy in this setting. In this review, we will assess the role of antiplatelet therapy in MINOCA with a focus on the pathophysiology, therapeutic targets, current evidence, and future directions according to its different etiologies.

Association Between Preinfarction Angina and Culprit Lesion Morphology in Patients With ST-Segment Elevation Myocardial Infarction: An Optical Coherence Tomography Study

BACKGROUND

Previous studies reported the cardiac protection effect of preinfarction angina (PIA) in patients with acute myocardial infarction (AMI). We sought to identify culprit-plaque morphology and clinical outcomes associated with PIA in patients with ST-segment elevation myocardial infarction (STEMI) using optical coherence tomography (OCT).

METHODS AND RESULTS

A total of 279 patients with STEMI between March 2017 and March 2019 who underwent intravascular OCT of the culprit lesion were prospectively included. Of them, 153 (54.8%) patients were presented with PIA. No differences were observed in clinical and angiographic data between the two groups, except STEMI onset with exertion was significantly less common in the PIA group (24.2 vs. 40.5%, p = 0.004). Patients with PIA exhibited a significantly lower incidence of plaque rupture (40.5 vs. 61.9%, p < 0.001) and lipid-rich plaques (48.4 vs. 69.0%, p = 0.001). The thin-cap fibroatheroma (TCFA) prevalence was lower in the PIA group, presenting a thicker fibrous cap thickness, although statistically significant differences were not observed (20.3 vs. 30.2%, p = 0.070; 129.1 ± 92.0 vs. 111.4 ± 78.1 μm, p = 0.088; respectively). The multivariate logistic regression analysis indicated that PIA was an independent negative predictor of plaque rupture (odds ratio: 0.44, 95% CI: 0.268-0.725, p = 0.001). No significant differences in clinical outcomes were observed besides unplanned revascularization.

CONCLUSION

Compared with the non-PIA group, STEMI patients with PIA showed a significantly lower prevalence of plaque rupture and lipid-rich plaques in culprit lesion, implying different mechanisms of STEMI attack in these two groups.

Fibroblast growth factor-21 as a novel metabolic factor for regulating thrombotic homeostasis

Fibroblast growth factor-21 (FGF-21) performs a wide range of biological functions in organisms. Here, we report for the first time that FGF-21 suppresses thrombus formation with no notable risk of bleeding. Prophylactic and therapeutic administration of FGF-21 significantly improved the degree of vascular stenosis and reduced the thrombus area, volume and burden. We determined the antithrombotic mechanism of FGF-21, demonstrating that FGF-21 exhibits an anticoagulant effect by inhibiting the expression and activity of factor VII (FVII). FGF-21 exerts an antiplatelet effect by inhibiting platelet activation. FGF-21 enhances fibrinolysis by promoting tissue plasminogen activator (tPA) expression and activation, while inhibiting plasminogen activator inhibitor 1 (PAI-1) expression and activation. We further found that FGF-21 mediated the expression and activation of tPA and PAI-1 by regulating the ERK1/2 and TGF-β/Smad2 pathways, respectively. In addition, we found that FGF-21 inhibits the expression of inflammatory factors in thrombosis by regulating the NF-κB pathway.

Use of Optical Coherence Tomography in MI with Non-obstructive Coronary Arteries

MI with non-obstructive coronary arteries (MINOCA) comprises an important minority of cases of acute MI. Many different causes have been implicated in the pathogenetic mechanism of MINOCA. Optical coherence tomography (OCT) is an indispensable tool for recognising the underlying pathogenetic mechanism when epicardial pathology is suspected. OCT can reliably identify coronary lesions not apparent on conventional coronary angiography and discriminate the various phenotypes. Plaque rupture and plaque erosion are the most frequently found atherosclerotic causes of MINOCA. Furthermore, OCT can contribute to the identification of ischaemic non-atherosclerotic causes of MINOCA, such as spontaneous coronary artery dissection, coronary spasm and lone thrombus. Recognition of the exact cause will enable therapeutic management to be tailored accordingly. The combination of OCT with cardiac magnetic resonance can set a definite diagnosis in the vast majority of MINOCA patients.

CVIT expert consensus document on primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) update 2022

Primary Percutaneous Coronary Intervention (PCI) has significantly contributed to reducing the mortality of patients with ST-segment elevation myocardial infarction (STEMI) even in cardiogenic shock and is now the standard of care in most of Japanese institutions. The Task Force on Primary PCI of the Japanese Association of Cardiovascular Interventional and Therapeutics (CVIT) society proposed an expert consensus document for the management of acute myocardial infarction (AMI) focusing on procedural aspects of primary PCI in 2018. Updated guidelines for the management of AMI were published by the European Society of Cardiology (ESC) in 2017 and 2020. Major changes in the guidelines for STEMI patients included: (1) radial access and drug-eluting stents (DES) over bare-metal stents (BMS) were recommended as a Class I indication, (2) complete revascularization before hospital discharge (either immediate or staged) is now considered as Class IIa recommendation. In 2020, updated guidelines for Non-ST-Elevation Myocardial Infarction (NSTEMI) patients, the followings were changed: (1) an early invasive strategy within 24 h is recommended in patients with NSTEMI as a Class I indication, (2) complete revascularization in NSTEMI patients without cardiogenic shock is considered as Class IIa recommendation, and (3) in patients with atrial fibrillation following a short period of triple antithrombotic therapy, dual antithrombotic therapy (e.g., DOAC and single oral antiplatelet agent preferably clopidogrel) is recommended, with discontinuation of the antiplatelet agent after 6 to 12 months. Furthermore, an aspirin-free strategy after PCI has been investigated in several trials those have started to show the safety and efficacy. The Task Force on Primary PCI of the CVIT group has now proposed the updated expert consensus document for the management of AMI focusing on procedural aspects of primary PCI in 2022 version.

Clopidogrel versus ticagrelor in the treatment of Chinese patients undergoing percutaneous coronary intervention: effects on platelet function assessed by platelet function tests and mean platelet volume

Background

Knowledge on the pharmacodynamic effects of antiplatelet drugs including clopidogrel and ticagrelor on Asian patients is scarce. We aim to evaluate the effects of the two drugs on platelet reactivity in the treatment of Chinese patients who underwent percutaneous coronary intervention (PCI), using two platelet function tests (PFT). Meanwhile, the relationship between mean platelet volume (MPV), a routine index of platelet size, and high on-treatment platelet reactivity (HPR) is also investigated.

Methods

Patients receiving dual antiplatelet therapy (DAPT) were scheduled for the assessment of platelet reactivity at 2–3 days after PCI. Two PFTs, light transmission aggregometry (LTA) and vasodilator-stimulated phosphoprotein (VASP)-FCM assay, were applied in the evaluation of platelet reactivity. The MPV was measured simultaneously with EDTA plasma using a Sysmex XN 2000 automated hematology analyzer.

Results

The final study population included the aspirin + clopidogrel group (n = 46) and the aspirin + ticagrelor group (n = 66). In the aspirin + ticagrelor group, the maximal light transmittance (LT) changes in response to 5 μM ADP assessed by LTA was obviously lower than that in the aspirin + clopidogrel group (P <  0.001). The platelet reactivity index (PRI) level in the VASP test was also markedly lower in the group given aspirin and ticagrelor (P <  0.001). There was a significant difference in HPR between the two groups. MPV showed a potent ability to predict the presence of HPR at VASP assay (AUC = 0.788, 95% CI: 0.701–0.875, P <  0.001) in receiver-operating characteristic curve analysis.

Conclusions

Compared with clopidogrel, ticagrelor has dramatically greater antiplatelet effect, with a superiority in suppressing platelet function and a lower HPR rate. In addition, there existed a significant independent association between MPV and high prevalence of HPR in the VASP assay.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00350-2.

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.

Plaque characteristics in patients with ST-segment elevation myocardial infarction and early spontaneous reperfusion

BACKGROUND

Early spontaneous reperfusion (ESR) is not an uncommon phenomenon in clinical settings.

AIMS

The aim of this study was to detect potential mechanisms of ESR in patients with STEMI.

METHODS

This prospective study enrolled a total of 241 consecutive patients with STEMI undergoing optical coherence tomography (OCT) from July 2016 to August 2019. Forty-five patients (18.7%) met angiographic ESR criteria (TIMI 3 flow on the initial angiogram). Among those without ESR (TIMI 0 flow on initial angiogram), 45 patients were assigned to the control group according to propensity score matching with the ESR group.

RESULTS

Although the baseline characteristics of the groups were comparable, non-ruptured plaque (62.2% vs 35.6%) predominated and plaque rupture (37.8% vs 64.4%) was less common in the ESR group (p=0.011). Red thrombus (44.4% vs 77.8%) was also less common in the ESR group (p=0.001). Lastly, compared to the control group, the ESR group underwent fewer emergent stent placements (68.9% vs 91.1%, p=0.008).

CONCLUSIONS

Relief of coronary occlusion induced by a non-ruptured plaque may contribute to ESR in patients with STEMI.

Phenotypes of Cardiovascular Diseases: Current Status and Future Perspectives

Cardiovascular diseases (CVDs) are a large group of diseases and have become the leading cause of morbidity and mortality worldwide. Although considerable progresses have been made in the diagnosis, treatment and prognosis of CVD, communication barriers between clinicians and researchers still exist because the phenotypes of CVD are complex and diverse in clinical practice and lack of unity. Therefore, it is particularly important to establish a standardized and unified terminology to describe CVD. In recent years, there have been several studies, such as the Human Phenotype Ontology, attempting to provide a standardized description of the disease phenotypes. In the present article, we outline recent advances in the classification of the major types of CVD to retrospectively review the current progresses of phenotypic studies in the cardiovascular field and provide a reference for future cardiovascular research.

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.

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.

Sex Differences in the Clinical Features and Outcomes of Patients with Acute Coronary Syndrome Treated with Two Generations (Absorb and Magmaris) of Bioresorbable Vascular Scaffolds

Background: Despite the developments in percutaneous coronary interventions (PCI), women are still more likely than men to have unfavorable outcomes after PCI performed in Acute Coronary Syndrome (ACS). The mechanisms of this phenomena are not fully understood. Potential benefits of bioresorbable scaffolds (BRS) may be particularly expressed in the female population. Nevertheless, the data available currently are inconsistent and limited. This study evaluated the gender-related differences in the short-term clinical outcomes in ACS patients treated with implantation of two generations of BRS (first generation, Absorb; second generation, Magmaris). Methods: The study was divided into two arms. To the first one, we qualified 160 patients with ACS treated with PCI who received 210 Absorb scaffolds. The second arm was composed of 193 patients with ACS who underwent PCI with Magmaris implantation. Results: There were no significant sex-related differences in primary endpoints (cardiovascular-death, myocardial infarction, in-stent thrombosis) or principal secondary endpoints (of target-lesion failure, scaffold restenosis, death from any reason, other cardiovascular events) in either generation of BRS in a 1-year follow-up. Conclusions: Both genders tended to have a similar outcome in routine clinical practice following BRS implantation due to ACS. The magnesium bioresorbable scaffold (Magmaris) early outcome seemed to be more favorable in comparison to the Absorb scaffold.

Spontaneous Coronary Artery Dissection: Pitfalls of Angiographic Diagnosis and an Approach to Ambiguous Cases

Spontaneous coronary artery dissection (SCAD) is a pathophysiologically distinct cause of acute coronary syndromes (ACS). It is increasingly recognized that optimal management is different from that for atherosclerotic ACS and that a SCAD diagnosis has specific long-term prognostic and therapeutic implications. Accurate diagnosis is therefore essential to ensure the best treatment of patients. At present this relies on the recognition of typical features of SCAD identified on invasive coronary angiography. Although most SCAD can be readily distinguished angiographically from alternative causes of ACS, false positive and false negative diagnoses remain common. In particular, sometimes non-SCAD presentations, including atherothrombosis, takotsubo cardiomyopathy, coronary embolism, coronary vasospasm, contrast streaming, and myocardial infarction with nonobstructive coronary arteries, can mimic angiographic features usually associated with SCAD. The authors present the combined experience from European and US SCAD referral centers reviewing the classical angiographic appearances of SCAD, presenting potential diagnostic pitfalls and exemplars of SCAD mimickers. The authors further review the benefits and limitations of intracoronary imaging in the context of SCAD. Finally, the authors discuss the investigation of ambiguous cases and an approach to minimize misdiagnosis in difficult cases.

Potent platelet inhibition with peri-procedural tirofiban may attenuate progression of atherosclerosis in patients with acute coronary syndromes

Organization of platelet-rich thrombus at the site of plaque disruption may contribute to rapid progression of atherosclerosis. This study was conducted to investigate if potent platelet inhibition therapy in patients with acute coronary syndromes (ACS) mitigates plaque progression. Patients enrolled in the EROSION study who presented with ACS caused by plaque erosion and underwent serial imaging of the culprit lesion by optical coherence tomography at baseline, 1 month, and 1 year were included. Among 49 patients, 32 (65.3%) patients were treated with glycoprotein IIb/IIIa inhibitor (GPI) in addition to aspirin and ticagrelor. The increase in area stenosis from baseline to 1-year follow-up was significantly smaller in patients treated with GPI, compared to those without GPI therapy (4.8% [- 1.6 to 10.9] vs. 9.6% [4.0 to 21.3], p = 0.031). The cohort was divided into 2 groups based on culprit lesion phenotype at 1 year: Group A, new layer formation at 1-year that was not present at baseline (n = 18); Group B, no new layer formation (n = 31). A new layer was less frequently found at 1 year in patients treated with GPI than in those without GPI (25.0% vs. 58.8%, p = 0.019). Group A, compared to Group B, was associated with a greater increase in area stenosis (19.0 ± 16.4% vs. 3.7 ± 7.1%; p < 0.001). Potent platelet inhibition with GPI in patients with ACS caused by plaque erosion was associated with lower incidence of new layer formation and less plaque progression.

Differential immunological signature at the culprit site distinguishes acute coronary syndrome with intact from acute coronary syndrome with ruptured fibrous cap: results from the prospective translational OPTICO-ACS study

AIMS

Acute coronary syndromes with intact fibrous cap (IFC-ACS), i.e. caused by coronary plaque erosion, account for approximately one-third of ACS. However, the underlying pathophysiological mechanisms as compared with ACS caused by plaque rupture (RFC-ACS) remain largely undefined. The prospective translational OPTICO-ACS study programme investigates for the first time the microenvironment of ACS-causing culprit lesions (CL) with intact fibrous cap by molecular high-resolution intracoronary imaging and simultaneous local immunological phenotyping.

METHODS AND RESULTS

The CL of 170 consecutive ACS patients were investigated by optical coherence tomography (OCT) and simultaneous immunophenotyping by flow cytometric analysis as well as by effector molecule concentration measurements across the culprit lesion gradient (ratio local/systemic levels). Within the study cohort, IFC caused 24.6% of ACS while RFC-ACS caused 75.4% as determined and validated by two independent OCT core laboratories. The IFC-CL were characterized by lower lipid content, less calcification, a thicker overlying fibrous cap, and largely localized near a coronary bifurcation as compared with RFC-CL. The microenvironment of IFC-ACS lesions demonstrated selective enrichment in both CD4+ and CD8+ T-lymphocytes (+8.1% and +11.2%, respectively, both P < 0.05) as compared with RFC-ACS lesions. T-cell-associated extracellular circulating microvesicles (MV) were more pronounced in IFC-ACS lesions and a significantly higher amount of CD8+ T-lymphocytes was detectable in thrombi aspirated from IFC-culprit sites. Furthermore, IFC-ACS lesions showed increased levels of the T-cell effector molecules granzyme A (+22.4%), perforin (+58.8%), and granulysin (+75.4%) as compared with RFC plaques (P < 0.005). Endothelial cells subjected to culture in disturbed laminar flow conditions, i.e. to simulate coronary flow near a bifurcation, demonstrated an enhanced adhesion of CD8+T cells. Finally, both CD8+T cells and their cytotoxic effector molecules caused endothelial cell death, a key potential pathophysiological mechanism in IFC-ACS.

CONCLUSIONS

The OPTICO-ACS study emphasizes a novel mechanism in the pathogenesis of IFC-ACS, favouring participation of the adaptive immune system, particularly CD4+ and CD8+ T-cells and their effector molecules. The different immune signatures identified in this study advance the understanding of coronary plaque progression and may provide a basis for future development of personalized therapeutic approaches to ACS with IFC.

TRIAL REGISTRATION

The study was registered at clinicalTrials.gov (NCT03129503).

Different Approaches in Therapy Aiming to Stabilize an Unstable Atherosclerotic Plaque

Atherosclerotic plaque vulnerability is a vital clinical problem as vulnerable plaques tend to rupture, which results in atherosclerosis complications—myocardial infarctions and subsequent cardiovascular deaths. Therefore, methods aiming to stabilize such plaques are in great demand. In this brief review, the idea of atherosclerotic plaque stabilization and five main approaches—towards the regulation of metabolism, macrophages and cellular death, inflammation, reactive oxygen species, and extracellular matrix remodeling have been presented. Moreover, apart from classical approaches (targeted at the general mechanisms of plaque destabilization), there are also alternative approaches targeted either at certain plaques which have just become vulnerable or targeted at the minimization of the consequences of atherosclerotic plaque erosion or rupture. These alternative approaches have also been briefly mentioned in this review.

Precision Phenomapping of Acute Coronary Syndromes to Improve Patient Outcomes

Acute coronary syndromes (ACS) are a global leading cause of death. These syndromes show heterogeneity in presentation, mechanisms, outcomes and responses to treatment. Precision medicine aims to identify and synthesize unique features in individuals, translating the acquired data into improved personalised interventions. Current precision treatments of ACS include immediate coronary revascularisation driven by ECG ST-segment elevation, early coronary angiography based on elevated blood cardiac troponins in patients without ST-segment elevation, and duration of intensified antithrombotic therapy according to bleeding risk scores. Phenotypically stratified analyses of multi-omic datasets are urgently needed to further refine and couple the diagnosis and treatment of these potentially life-threatening conditions. We provide definitions, examples and possible ways to advance precision treatments of ACS.

Can OCT change the therapeutic strategy in ACS due to plaque erosion?

The pathophysiology of acute coronary syndromes was thought to be coronary thrombosis over a plaque rupture. Autopsy studies revealed that not all cases were due to plaque rupture, even denuded endothelium or calcific nodule can beget a thrombus. Introduction of OCT made, in vivo recognition of lesion morphology clear. Plaque ruptures are most common and need primary angioplasty. Recent studies established plaque erosion is responsible for ACS in one third of the cases and majority of them present as Non ST elevation myocardial infarction and commonly found in young patients without major risk factors. Evidence from recent studies suggested that stenting can be deferred and they can be managed conservatively with good long term outcomes. More randomized trials are needed comparing plaque rupture and plaque erosion as regards conservative versus invasive management. If these studies substantiate the concept of conservative management, it will lead to a paradigm shift in their management.

The Spectrum of ACS: Towards a More Personalized Approach

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Hyperhomocysteinemia as the only risk factor in a young man presenting with ST-elevation myocardial infarction

Hyperhomocysteinemia has been established as a risk factor for cardiovascular events. This case of a 23-year-old male, presenting with acute coronary thrombosis and unremarkable past medical history, highlights the importance of measuring homocysteine levels in young individuals with acute coronary syndromes, especially those without conventional risk factors. <Learning objective: Hyperhomocysteinemia could be rarely the only risk factor causing an acute coronary syndrome, especially in very young individuals; Optical coherence tomography could provide valuable information regarding the cause of occlusion in an unexpected clinical presentation; Gene testing for thrombophilia should be considered for very young individuals with acute coronary syndrome without conventional risk factors; Randomized controlled trials have failed to prove a clinical benefit in patients treated with folic acid.>.

Mean Platelet Volume/Platelet Count Ratio and Culprit Plaque Morphologies: An Optical Coherence Tomography Study in Patients with ST Segment Elevation Myocardial Infarction

This study aimed to investigate the predictive value of mean platelet volume/platelet count ratio (MPR) for coronary plaque features in patients with ST segment elevation myocardial infarction (STEMI). A total of 275 STEMI patients undergoing preintervention optical coherence tomography examination were included, with 142 categorized as plaque rupture (PR) and 133 as plaque erosion (PE). Multivariable logistic regression showed higher MPR was an independent predictor of PR (tertile 3 vs tertile 1, odds ratio: 6.257, 95% confidence interval: 1.586-24.686, P = 0.009). MPR showed better diagnostic performance than other platelet indices. The optimal MPR threshold for diagnosing PR was 0.0473 (sensitivity: 0.721, specificity: 0.647). When added to models of established risk factors, MPR significantly improved the predictive accuracy of PR (area under the curve: 0.767 vs 0.722, P _difference = 0.004). In conclusion, for STEMI patients, MPR was an independent predictor of PR and improved diagnostic performance for PR.

Morphological Characteristics of Eroded Plaques with Noncritical Coronary Stenosis: An Optical Coherence Tomography Study

Aims: Recent studies suggested plaque erosion with noncritical stenosis could be treated distinctly from that with critical stenosis, but their morphological features remained largely unknown. The present study aimed to investigate morphological features of eroded plaques with different lumen stenosis using optical coherence tomography (OCT).

Methods: A total of 348 ST-segment elevated myocardial infarction patients with culprit OCT-defined plaque erosion (OCT-erosion) were analyzed. Based on the severity of lumen area stenosis, all patients with OCT-erosions were divided into the following three groups: Group A (area stenosis ＜50%, n =50); Group B (50% ≤ area stenosis ＜75%, n =146); Group C (area stenosis ≥ 75%, n =152).

Results: Compared with patients in Groups A and B, patients in Group C were older ( p =0.008) and had higher prevalence of hypertension ( p =0.029). Angiographic analysis showed that 72.0% of the eroded plaques in Group A were located in the left anterior descending artery, followed by 67.8% in Group B, and 53.9% in Group C ( p =0.039). OCT analysis showed that Group A had the highest prevalence of fibrous plaques ( p ＜0.001) and nearby bifurcation ( p =0.036), but the lowest prevalence of lipid-rich plaques ( p ＜0.001), macrophage accumulation ( p ＜0.001), microvessels ( p =0.009), cholesterol crystals ( p ＜0.001), and calcification ( p =0.023). Multivariable regression analysis showed fibrous plaque (odds ratio [OR]: 3.014, 95% confidence interval [CI]: 1.932–4.702, p ＜0.001) and nearby bifurcation (OR: 1.750, 95% CI: 1.109–2.761, p =0.016) were independently associated with OCT-erosion with an area stenosis of ＜75%.

Conclusions: More than half of OCT-erosions presented with ＜75% area stenosis, having distinct morphological features from those of OCT-erosions with critical stenosis. Fibrous plaque and nearby bifurcation were independently associated with noncritically stenotic OCT-erosion, suggesting that eroded plaques might need individualized treatment.

Optical Coherence Tomography based treatment approach for patients with Acute Coronary Syndrome

INTRODUCTION

Areas covered:In this review, we outline the underlying causes of acute coronary syndrome (ACS) as evaluated by optical coherence tomography (OCT). We report both the definitions of each mechanism and its frequency as reported in the literature to date. Finally, we present an algorithm based on the findings in the review that gives an outlined approach to perform intervention on ACS patients.Expert opinion:Although the most common and most accepted intervention in ACS cases is stent implantation, data suggest a stentless approach in cases of plaque erosion, which generally occurs in younger patients presenting with an acute coronary syndrome that have TIMI flow of 2/3 and either a small or large burden of thrombus and underlying stenosis of less than 50%.

High Plasma Myeloperoxidase Is Associated with Plaque Erosion in Patients with ST-Segment Elevation Myocardial Infarction

We aimed to investigate the association between plasma myeloperoxidase (MPO) and plaque erosion in patients presenting with ST-segment elevation myocardial infarction (STEMI). Two hundred and fifty-two patients with STEMI who underwent optical coherence tomography (OCT) evaluation of culprit lesion were prospectively enrolled. Of them, 92 and 80 patients were identified with plaque rupture and plaque erosion, respectively. Plasma MPO levels, measured using enzyme-linked immunoassay, were significantly higher in patients with plaque erosion versus plaque rupture (median (interquartile range), 96.3 ng/mL [44.2-173.3] vs. 41.7 ng/mL (29.2-66.3); p < 0.001). Multivariable logistic regression analysis indicated that plasma MPO was independently associated with plaque erosion (odds ratio, 3.25; 95% confidence interval, 1.37-7.76; p = 0.008). The area under the receiver-operating characteristic curve was 0.75 for MPO to discriminate between plaque erosion and plaque rupture. Plasma MPO level significantly correlated with plaque erosion in patients with STEMI.

Acute coronary syndrome with large thrombus successfully managed with no-stenting revascularization based on intravascular imaging in a patient with hyperhomocysteinemia: a case report

Background

Hyperhomocysteinemia is caused by genetic and environmental factors, which can result in systemic arteriosclerosis and arteriovenous thrombosis including acute coronary syndrome. Thrombus burden in patients with acute coronary syndrome and hyperhomocysteinemia might involve the culprit lesion as compared with those without any coagulopathy. The primary percutaneous coronary intervention with stent implantation had been established as the treatment strategy for patients with acute coronary syndrome. However, in patients with acute coronary syndrome with high thrombus burden or uncontrolled coagulopathy, stent implantation might lead to slow-flow phenomenon or stent thrombosis. Therefore, the treatment strategy in these patients was not established.

Case presentation

A 49-year-old Japanese man with history of splenic infarction of unknown cause had continued anticoagulant therapy since its diagnosis, but stopped taking the medication several months ago. He presented with sudden-onset chest dorsalgia. Contrast computed tomography showed a small pulmonary embolism and his troponin I level was elevated on initial laboratory test. Coronary angiography revealed a contrast defect caused by a large thrombus from the proximal to mid portion of the left anterior descending artery. Near-infrared spectroscopy–intravascular ultrasonography showed a large amount of thrombus without lipid plaque. Therefore, revascularization was performed using a thrombus-aspiration catheter and intracoronary thrombolysis. In addition, , hyperhomocysteinemia and a deep vein thrombosis occurred. He was diagnosed with acute coronary syndrome complicated with pulmonary embolism and deep vein thrombosis simultaneously induced by hyperhomocysteinemia. After 1 week of antithrombotic therapy, near-infrared spectroscopy–intravascular ultrasonography and optical coherence tomography revealed a decreased thrombus and no significant residual organic stenosis in the left anterior descending artery. He continued conservative therapy with antithrombotic medications including aspirin and warfarin and had no cardiovascular events after discharge. Follow-up coronary angiography and optical coherence tomography at 9 months revealed complete disappearance of the thrombus and no severe stenosis.

Conclusions

Hyperhomocysteinemia should be considered as a cause of arterial vein thrombosis of unknown cause. The antithrombotic therapy and percutaneous revascularization without stenting based on intravascular imaging might be a safe and effective treatment option in patients with acute coronary syndrome complicated with hyperhomocysteinemia.

Optical coherence tomography: fundamentals and clinical utility

Although coronary angiography is the standard method employed to assess the severity of coronary artery disease and to guide treatment strategies, it provides only 2D image of the intravascular lesions. In contrast, intravascular imaging modalities such as optical coherence tomography (OCT) produce cross-sectional images of the coronary arteries at a far greater spatial resolution, capable of accurately determining vessel size as well as plaque morphology, eliminating many of the disadvantages inherent to angiography. This review will discuss the role of OCT in the catherization laboratory for the assessment and management of coronary disease.

Systemic and local factors associated with reduced thrombolysis in myocardial infarction flow in ST-segment elevation myocardial infarction patients with plaque erosion detected by intravascular optical coherence tomography

Local factors of plaque rupture (e.g. lipid burden) are related to preprocedural thrombolysis in myocardial infarction (TIMI) flow grade during primary percutaneous coronary intervention (PCI). However, the pathological mechanism differs between plaque erosion and rupture. We aimed to identify the factors associated with reduced TIMI flow in plaque erosion. A total of 329 ST-segment elevation myocardial infarction (STEMI) patients with optical coherence tomography (OCT) identified plaque erosion were divided into 2 groups by preprocedural TIMI flow grade [TIMI 0-1 group (n = 219) and TIMI 2-3 group (n = 110)]. Patients in TIMI 0-1 group were older (age > 50 years, 68.5% vs. 51.8%, P = 0.003), and had more diabetes mellitus (18.3% vs. 8.2%, P = 0.015). Plaque erosion with TIMI flow 0-1 was less frequently located in the left anterior descending artery (LAD, 58.4% vs. 72.7%, P = 0.011), but more frequently located in the right coronary artery (RCA, 34.2% vs. 7.3%, P = 0.001) than those with TIMI flow 2-3. TIMI 0-1 group had more lipid plaques (53.9% vs. 41.8%, P = 0.039), macrophage accumulation (59.8% vs. 41.8%, P = 0.002), and calcification (34.2% vs. 21.8%, P = 0.020). In the multivariable analysis, age > 50 years, diabetes mellitus, RCA location, and macrophage accumulation were the independent predictors of reduced TIMI flow grade in STEMI patients with plaque erosion. Systemic factors (older age and diabetes mellitus) and local factors (RCA location and macrophage accumulation) were independently associated with reduced coronary flow in STEMI patients with plaque erosion. CLINICAL TRIAL REGISTRATION : ClinicalTrials.gov NCT03084991 May 17, 2017 (retrospectively registered).

Small vessel coronary artery disease: How small can we go with myocardial revascularization?

The issue of small coronary artery atherosclerosis represents an intriguing aspect of coronary artery disease, which is related with higher rates of peri- and post-procedural complications and impaired long-term outcome. This problem is further complicated by the unclear definition of small coronary vessel. Recent randomized controlled trials have provided new data on possible novel interventional treatment of small coronary vessels with drug-coated balloons instead of traditional new-generation drug-eluting stent implantation. Also, the conservative management represents a therapeutic option in light of the results of the recent ISCHEMIA trial. The current article provides an overview of the most appropriate definition, interventional management, and prognosis of small coronary artery atherosclerosis.