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

Bivalirudin vs. Heparin on Radial Artery Thrombosis during Transradial Coronary Intervention: An Optical Coherence Tomography Study

Objectives

This study aimed to evaluate the antithrombotic efficacy between bivalirudin and unfractionated heparin (UFH) on radial artery thrombosis (RAT) during transradial coronary intervention (TRI) by optical coherence tomography (OCT).

Methods and Results

We consecutively reviewed a total of 307 patients who underwent radial artery OCT inspection after TRI in our centre from October 2017 to January 2019; afterwards, 211 screened patients were divided into the UFH group (n = 144) and the bivalirudin group (n = 67) according to their anticoagulation strategy during TRI. The thrombosis in the radial artery was observed in 51 cases (24.17%) with a median thrombus volume of 0.054 mm³ (0.024, 0.334) and median thrombus score of 7 (4, 15). Thrombus occurred in 28 cases in the bivalirudin group with an incidence of 41.8%, which was significantly higher than that in the UFH group (n = 23, 16.0%, P < 0.001). This difference was even more remarkable after propensity score matching (bivalirudin group n = 22, 42.3% vs. UHF group n = 11, 13.9%, P < 0.001). Multivariate logistic analysis revealed that bivalirudin increased the RAT risk by 3.872 times (95% CI 2.006–8.354, P < 0.001) after adjustment for the other predictors.

Conclusion

In this present study, the use of bivalirudin was associated with a higher risk of RAT than UFH. It highlighted UFH should be a more considerable choice to prevent radial artery access thrombosis in TRI.

Determinants of ST-segment elevation myocardial infarction as clinical presentation of acute coronary syndrome

Antiplatelet agents and statin therapies are widely used in patients with known cardiovascular disease. Plaque rupture (PR) and plaque erosion (PE) are the most frequent underlying mechanisms of acute coronary syndromes (ACS). The conditions and medications that are associated with ST-segment elevation myocardial infarction (STEMI) following PR or PE have not been systematically studied. A total of 838 ACS patients (494 with STEMI, 344 with NSTE-ACS) who were diagnosed with PR or PE by optical coherence tomography were included. The patients were categorized into two groups based on underlying pathology, and the baseline characteristics and culprit plaque morphology associated with STEMI were investigated within each group. Among 838 patients, 467 (55.7%) had PR, and 371 (44.3%) were diagnosed with PE. Among patients with PR, older age, hyperlipidemia, no antiplatelet therapy, higher level of low-density lipoprotein cholesterol, and greater lipid burden and macrophage infiltration were associated with increased probability of STEMI. Among patients with PE, no dual antiplatelet therapy and no statin therapy were associated with increased probability of STEMI. The incidence of STEMI caused by PR was significantly lower on antiplatelet therapy (P < 0.001), and the incidence of STEMI caused by PE was significantly lower on antiplatelet therapy (P < 0.001) or on statin therapy (P < 0.001). Antiplatelet therapy is associated with lower probability of STEMI, regardless of underlying pathology, and statin therapy is associated with lower probability of STEMI in PE as clinical presentation of ACS. Statin therapy prior to the onset of acute coronary syndromes (ACS) may reduce the probability of plaque rupture. Antiplatelet therapy prior to the onset of ACS is associated with reduced probability of ST-segment elevation myocardial infarction (STEMI) following both plaque rupture and plaque erosion, and dual antiplatelet therapy offers additional protection compared to a single antiplatelet agent in plaque erosion. The combination of statin and antiplatelet therapy may have an additive effect on reducing the probability of STEMI caused by plaque erosion. Yellow: lipid pool(necrotic core); red: fibrin-rich thrombus; gray; platelet-rich thrombus.

Optical Coherence Tomography for the Diagnosis of Exercise-Related Acute Cardiovascular Events and Inconclusive Coronary Angiography

Objectives

The aim of this study is to assess the utility of optical coherence tomography (OCT) in patients with exercise-related acute coronary syndrome (ACS) presenting with inconclusive angiographic findings.

Background

Regular physical activity reduces the incidence of cardiovascular events. Nevertheless, the risk of ACS or sudden cardiac death (SCD) increases during sport. In adults older than 35 years, exercise-related ACS or SCD is associated with plaque rupture, but not infrequently patients present ambiguous angiographic findings.

Methods

Between September 2015 and January 2020, patients admitted for ACS or SCD triggered by physical exertion and with coronary stenosis ≤50% were included in this prospective observational study. OCT was performed on the artery deemed to be responsible of the event.

Results

Ten patients were enrolled, predominantly men (80%) of middle age (51 years old, IQR 41–63) with low cardiovascular risk burden. Cycling was the most frequent (50%) exercise-related trigger, 8 patients were regular sport practitioners, and 7 had the clinical event during strenuous exertion. Five patients presented with non-ST-elevation ACS, two with ST-elevation ACS, and three with SCD. Angiographic analysis showed nonsignificant stenosis in all patients (42% stenosis, IQR 36–46). OCT identified the etiology of the event in 9 patients (4 plaque erosion, 3 plaque rupture, 1 eruptive calcific nodule, and 1 coronary dissection). Treatment was adjusted according to OCT findings.

Conclusions

OCT is a valuable technique to identify the etiology of exercise-related ACS or SCD in patients with nonobstructive coronary arteries and, as a result, may lead to a more specific treatment.

Circadian variations in pathogenesis of ST-segment elevation myocardial infarction: an optical coherence tomography study

Previous studies have reported a circadian variation in the onset of ST-segment elevation myocardial infarction (STEMI). However, underlying mechanisms for the circadian variation have not been fully elucidated. We investigated the relationship between onset of STEMI and the underlying pathology using optical coherence tomography (OCT). Patients with a diagnosis of STEMI were selected from a multicenter OCT registry. Patients were divided into 4 groups based on the estimated time of onset (00:00-05:59, 06:00-11:59, 12:00-17:59, or 18:00-23:59). Underlying pathologies of MI (plaque rupture, plaque erosion, and calcified plaque) were compared among the 4 groups. Among 648 patients, plaque rupture was diagnosed in 386 patients (59.6%), plaque erosion in 197 patients (30.4%), and calcified plaque in 65 patients (10.0%). A marked circadian variation was detected in the incidence of plaque rupture with a peak at 09:00, whereas it was not evident in plaque erosion or calcified plaque. The probability of plaque rupture significantly increased in the periods of 06:00-11:59 [odds ratio (OR) 2.13, 95% confidence interval (CI) 1.30-3.49, p = 0.002] and 12:00-17:59 (OR 2.10, 95% CI 1.23-3.58, p = 0.005), compared to the period of 00:00-05:59. This circadian pattern was observed only during weekdays (p = 0.010) and it was not evident during the weekend (p = 0.742). Plaque rupture occurred most frequently in the morning and this circadian variation was evident only during weekdays. Acute MI caused by plaque rupture may be related to catecholamine surge.

The association between glucose-related variables and plaque morphology in patients with ST-segment elevated myocardial infarction

Background

Plaque rupture (PR) and plaque erosion (PE) are main causes of acute myocardial infarction with different demographic and histology characteristics and need different treatment strategy. PR and PE can be identified with optical coherence tomography (OCT) accurately, but convenient and effective noninvasive markers for them are rarely found. History of diabetes mellitus (DM) was reported to be a potential predictor of PR in ST-segment elevated myocardial infarction (STEMI) patients, but the predictive value of other glucose-related variables for it is still uncertain. Present study aimed to clear the relationship between some glucose-related variables and plaque morphology in patients with STEMI.

Methods

We consecutively enrolled 872 STEMI patients and divided them into PR group (n = 616) and PE group (n = 256) based on OCT diagnostic criteria. The relationship of glucose-related variables, including random plasma glucose on admission (ARPG), glycosylated hemoglobin (HbA1c), post-PCI fasting plasma glucose (PFPG), DM history, glucose variable tendency (GVT) and the acute-to-chronic glycemic ratio (A/C), to the PR risk of STEMI patients was analyzed. The correlation between the glucose-related variables and plaque morphology was analyzed meanwhile.

Results

Among the glucose-related variables, ARPG and GVT were confirmed to be independent predictors for PR after adjusting for other traditional risk factors in nondiabetic patients. The higher the ARPG level, the more PR risk the STEMI patients had. And high HbA1c and APPG were demonstrated to have a weak and positive correlation with lipid constituents and stenosis degree of culprit vessel.

Conclusions

Compared to HbA1c, DM history, and some other glucose-related variables, ARPG and GVT were risk factors for PR in STEMI patients, especially those without DM. And high HbA1c and ARPG were positively correlated with the development of vulnerable plaque in culprit vessels.

Trial registration Present study is a retrospective one and the population came from the EROSION study of our center previously. It was approved by the Ethics Committee of the Second Affiliated Hospital of Harbin Medical University (Approval reference number, KY2017-249), and all patients provided written informed consent prior to the inclusion in the study and the investigation conformed to the principles outlined in the Declaration of Helsinki.

Degree of luminal narrowing and composition of thrombus in plaque erosion

As the degree of luminal narrowing increases, shear stress increases, and high shear stress is known to activate platelets. However, the relationship between the degree of luminal narrowing and the composition of thrombus in patients with plaque erosion has not been studied. A total of 148 patients with plaque erosion and thrombus detected by optical coherence tomography were divided into tertiles based on the minimum lumen area (MLA) at the culprit lesion. Thrombus was categorized as platelet-rich or fibrin-rich. Among 148 patients, 50 (34%) were in the mild stenosis group, 49 (33%) were in the moderate stenosis group, and 49 (33%) were in the severe stenosis group. The composition of thrombus was significantly different among the 3 groups (prevalence of platelet-rich thrombus was 60% in the mild stenosis group; 78% in the moderate stenosis group; and 84% in the severe stenosis group; P = 0.021). The pattern of fibrin-rich thrombus showed the opposite: 40%, 22%, and 16%, respectively. In the multivariate analysis, current smoking was independently associated with fibrin-rich thrombus (odds ratio [OR] 2.364 [95% CI 1.004-5.567], P = 0.049). This study demonstrated that platelet-rich thrombus was the predominant type of thrombus in plaque erosion. The prevalence of fibrin-rich thrombus was highest in the mild stenosis group.

Characteristics of culprit lesions in young patients with metabolic syndrome and classic cardiovascular risk factors

The association between cardiovascular risk factors (CVRFs) and characteristics of coronary plaque in young patients has remained to be fully elucidated. Therefore, the present study sought to determine the association between CVRFs and phenotypes of culprit coronary plaques revealed by optical coherence tomography (OCT) in young patients with stable coronary heart disease (CHD) and acute coronary syndrome (ACS). OCT imaging pullback was performed at corresponding sites on 123 lesions in 123 young patients (age, 36±7 years), including those with stable CHD and ACS. Patients with analyzable OCT images were classified as having thin-cap fibroatheromas (TCFAs), plaque rupture, macrophage accumulation, calcified nodule, vasa vasorum, cholesterol crystal and erosion. TCFAs were more prevalent in patients with metabolic syndrome (MetS) than in those without MetS (P=0.020). Plaque rupture was more common in smokers than in non-smokers (P=0.002). Multivariate analysis indicated that MetS was independently associated with TCFAs (P=0.041) and smoking was independently associated with plaque rupture (P=0.006). Young patients with MetS were demonstrated to have more extensive TCFAs and young smokers had a higher prevalence of culprit plaque rupture.

Ability of FFR-CT to detect the absence of hemodynamically significant lesions in patients with high-risk NSTE-ACS admitted in the emergency department with chest pain, study design and rationale

Background

In the era of High-sensitive troponin (hs-Tn), up to 50% of patients with a mild increase of hs-Tn will finally have a normal invasive coronary angiogram. Fractional Flow Reserve (FFR) derived from coronary computed tomographic angiography (FFR-CT) has never been used as a non-invasive tool for the diagnosis of coronary artery disease in patients with high-risk acute coronary syndrome without ST segment elevation (NSTE-ACS).

Aims

The study aims to determine the role of coronary CT angiography and FFR-CT in the setting of high-risk NSTE-ACS.

Methodology

We will conduct a prospective trial, enrolling 250 patients admitted with high-risk NSTE-ACS who will rapidly undergo a coronary CT angiography and then a coronary angiography with FFR measurements. Results of coronary CT, FFR-CT and coronary angiography (± FFR) will be compared.

Potential significance

In conclusion, non-invasive identification of patients with high-risk NSTE-ACS who could avoid coronary angiography would reduce procedure related risks and medical costs.

Rescue treatment and follow-up intervention of a left main acute myocardial infarction with typical carina shift under 3D optical coherence tomography: A case report

BACKGROUND

Coronary intervention for bifurcation lesions is still challenging for interventional cardiologists. Left main (LM) bifurcation lesions have a higher risk due to the vast blood supply in this area and treatment choice is difficult. Ostial compromise of the side branch decreases patient prognosis, and its management is still an issue despite the different strategies and devices available.

CASE SUMMARY

A 42-year-old male patient was admitted to hospital due to chest pain and syncope. Coronary angiography showed acute LM occlusion. Following thrombus aspiration, a LM bifurcation lesion remained. Coronary angiography was repeated one week later, and at the same time, 3D optical coherence tomography (OCT) was carried out to better show the geometry of the bifurcation, which confirmed that the stenosis in the ostial left circumflex artery was caused by a long carina. After assessment of the plaque characteristics and the minimum lumen area, the cross-over strategy, kissing balloon inflation and proximal optimization technique were chosen to treat the bifurcation lesion. A “moving” carina was found twice during the intervention. Good stent apposition and expansion were confirmed by OCT after proximal optimization technique. The three-month follow-up showed good recovery and normal cardiac function.

CONCLUSION

3D-OCT can facilitate decision-making for coronary interventions in patients with critical bifurcation lesions.

Two distinct phenotypes of plaque erosion assessed by multimodality intracoronary imaging: a case series

Background 

Pathological studies have reported that patients with acute coronary syndrome (ACS) may have different plaque morphologies at culprit lesions, and one of the underlying mechanisms for ACS is plaque erosion. However, the morphological features of plaque erosion obtained by multiple intracoronary imaging modalities have not been fully elucidated.

Case summary 

We experienced two cases with ACS of culprit lesions exhibiting optical coherence tomography (OCT)-defined plaque erosion. Additional examinations using near-infrared spectroscopy (NIRS)–intravascular ultrasound and coronary angioscopy suggested the presence of two distinct phenotypes of plaque erosion. These two types of erosion differ in the extent of NIRS-derived lipid core burden and coronary angioscopy-derived luminal surface colour.

Discussion 

OCT-defined plaque erosion may not be the unique entity but have at least two distinct plaque morphologies, and NIRS and/or coronary angioscopy may provide incremental ability of discriminating these plaque phenotypes classified as plaque erosion by OCT.

Plaque erosion: a new in vivo diagnosis and a potential major shift in the management of patients with acute coronary syndromes

Pathology and in vivo imaging studies have identified superficial plaque erosion as a frequent and important mechanism underlying acute coronary syndromes (ACS). In contrast with plaque rupture, the pathophysiological mechanisms leading to plaque erosion remain poorly understood. The advent of intravascular imaging techniques, particularly optical coherence tomography, has aided understanding of this mode of ACS in vivo by complementing previous insights from pathology studies. Appreciation of the distinct biological and clinical mechanisms of plaque erosion points to the possibility of tailored management strategies for patients presenting with ACS.

Intravascular Polarimetry for Tissue Characterization of Coronary Atherosclerosis

The microscopic tissue structure and organization influence the polarization of light. Intravascular polarimetry leverages this compelling intrinsic contrast mechanism by using polarization-sensitive optical frequency domain imaging to measure the polarization properties of the coronary arterial wall. Tissues rich in collagen and smooth muscle cells appear birefringent, while the presence of lipid causes depolarization, offering quantitative metrics related to the presence of important components of coronary atherosclerosis. Here, we review the basic principle, the interpretation of polarization signatures, and first clinical investigations of intravascular polarimetry and discuss how this extension of contemporary intravascular imaging may advance our knowledge and improve clinical practice in the future.

Clinical and Laboratory Predictors for Plaque Erosion in Patients With Acute Coronary Syndromes

Background Plaque erosion is responsible for 25% to 40% of patients with acute coronary syndromes (ACS). Recent studies suggest that anti-thrombotic therapy without stenting may be an option for this subset of patients. Currently, however, an invasive procedure is required to make a diagnosis of plaque erosion. The aim of this study was to identify clinical or laboratory predictors of plaque erosion in patients with ACS to enable a diagnosis of erosion without additional invasive procedures. Methods and Results Patients with ACS who underwent optical coherence tomography imaging were selected from 11 institutions in 6 countries. The patients were classified into plaque rupture, plaque erosion, or calcified plaque, and predictors were identified using multivariable logistic modeling. Among 1241 patients with ACS, 477 (38.4%) patients were found to have plaque erosion. Plaque erosion was more frequent in non-ST-segment elevation-ACS than in ST-segment-elevation myocardial infarction (47.9% versus 29.8%, P=0.0002). Multivariable logistic regression models showed 5 independent parameters associated with plaque erosion: age <68 years, anterior ischemia, no diabetes mellitus, hemoglobin >15.0 g/dL, and normal renal function. When all 5 parameters are present in a patient with non-ST-segment elevation-ACS, the probability of plaque erosion increased to 73.1%. Conclusions Clinical and laboratory parameters associated with plaque erosion are explored in this retrospective registry study. These parameters may be useful to identify the subset of ACS patients with plaque erosion and guide them to conservative management without invasive procedures. The results of this exploratory analysis need to be confirmed in large scale prospective clinical studies. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT03479723.

Reassessing the Mechanisms of Acute Coronary Syndromes

The mechanisms that underlie superficial erosion, a cause of coronary thrombosis distinct from plaque rupture, have garnered recent interest. In an era of improved control of traditional risk factors, such as LDL (low-density lipoprotein), plaque erosion may assume greater clinical importance. Plaques complicated by erosion tend to be matrix-rich, lipid-poor, and usually lack prominent macrophage collections, unlike plaques that rupture, which characteristically have thin fibrous caps, large lipid pools, and abundant foam cells. Thrombi that complicate superficial erosion seem more platelet-rich than the fibrinous clots precipitated by plaque rupture. The pathogenesis of plaque rupture probably does not pertain to superficial erosion, a process heretofore little understood mechanistically. We review here data that support a substantial shift in the mechanisms of the thrombotic complications of atherosclerosis. We further consider pathophysiologic processes recently implicated in the mechanisms of erosion. Multiple processes likely predispose plaques to superficial erosion, including experiencing disturbed flow, basement membrane breakdown, endothelial cell death, and detachment potentiated by innate immune activation mediated through pattern-recognition receptors and endothelial-to-mesenchymal transition. Monocytes/macrophages predominate in the pathogenesis of plaque rupture and consequent thrombosis, but polymorphonuclear leukocytes likely promote endothelial damage during superficial erosion. The formation of neutrophil extracellular traps probably perpetuates and propagates intimal injury and potentiates thrombosis due to superficial erosion. These considerations have profound clinical implications. Acute coronary syndromes because of erosion may not require immediate invasive therapy. Understanding the biological bases of erosion points to novel therapies for acute coronary syndrome caused by erosion. Future research should probe further the mechanisms of superficial erosion, and develop point-of-care tests to distinguish acute coronary syndromes provoked by erosion versus rupture that may direct more precision management. Future clinical investigations should evaluate intervening on the targets that have emerged from experimental studies and the management strategies that they inform.

Clinical use of intracoronary imaging. Part 2: acute coronary syndromes, ambiguous coronary angiography findings, and guiding interventional decision-making: an expert consensus document of the European Association of Percutaneous Cardiovascular Interventions

This consensus document is the second of two reports summarizing the views of an expert panel organized by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on the clinical use of intracoronary imaging including intravascular ultrasound (IVUS), optical coherence tomography (OCT), and near infrared spectroscopy (NIRS)-IVUS. Beyond guidance of stent selection and optimization of deployment, invasive imaging facilitates angiographic interpretation and may guide treatment in acute coronary syndrome. Intravascular imaging can provide additional important diagnostic information when confronted with angiographically ambiguous lesions and allows assessment of plaque morphology enabling identification of vulnerability characteristics. This second document focuses on useful imaging features to identify culprit and vulnerable coronary plaque, which offers the interventional cardiologist guidance on when to adopt an intracoronary imaging-guided approach to the treatment of coronary artery disease and provides an appraisal of intravascular imaging-derived metrics to define the haemodynamic significance of coronary lesions.

Immune-Mediated Inflammation in Vulnerable Atherosclerotic Plaques

Atherosclerosis is a chronic long-lasting vascular disease leading to myocardial infarction and stroke. Vulnerable atherosclerotic (AS) plaques are responsible for these life-threatening clinical endpoints. To more successfully work against atherosclerosis, improvements in early diagnosis and treatment of AS plaque lesions are required. Vulnerable AS plaques are frequently undetectable by conventional imaging because they are non-stenotic. Although blood biomarkers like lipids, C-reactive protein, interleukin-6, troponins, and natriuretic peptides are in pathological ranges, these markers are insufficient in detecting the critical perpetuation of AS anteceding endpoints. Thus, chances to treat the patient in a preventive way are wasted. It is now time to solve this dilemma because clear results indicate a benefit of anti-inflammatory therapy per se without modification of blood lipids (CANTOS Trial, NCT01327846). This fact identifies modulation of immune-mediated inflammation as a new promising point of action for the eradication of fatal atherosclerotic endpoints.

Culprit Lesion Characteristics in Young Patients with Hyperhomocysteinemia

Background

The relationships between culprit coronary plaque characteristics and hyperhomocysteinemia (HHcy) are not fully understood in young patients. In this study we investigated the relationship between culprit atherosclerotic plaque phenotype assessed by optical coherence tomography (OCT) and hyperhomocysteinemia (HHcy) in young patients.

Material/Methods

We investigated the OCT imaging and HHcy of 123 lesions in 123 young patients (≤45 years of age). According to OCT images, culprit lesions were classified as thin-cap fiber atheroma (TCFA), thrombus, and other. The 123 patients were grouped as: HHcy group (53 cases, HHcy ≥15.5 μmol/l) and control group (70 cases, HHcy <15.5 μmol/l).

Results

Compared with the control group, the HHcy group had a higher proportion of OCT-TCFA (p=0.03), OCT-vasa vasorum (p=0.013), and OCT-thrombus (p=0.012), and a larger lipid arc (p=0.002). HHcy (P=0.037) and metabolic syndrome (MetS) (P=0.016) remained independent predictors of TCFAs. HHcy (P=0.026) and smoking (P=0.005) remained independent determinants of thrombus.

Conclusions

HHcy and MetS are associated with TCFAs, and HHcy and smoking are associated with thrombus in young patients with coronary artery disease.

Vascular response and intrastent thrombus in the early phase after drug-eluting versus bare-metal stent implantation in patients with ST-segment elevation myocardial infarction: An observational, single-center study

BACKGROUND AND OBJECTIVES

Second-generation drug-eluting stents (G2-DES) are associated with a lower rate of acute and subacute stent thrombosis compared with bare-metal stent (BMS) in the setting of ST-segment elevation myocardial infarction (STEMI). In this study, our aim was to compare the vascular response and thrombus burden between G2-DES and BMS in early-phase STEMI.

METHODS

Between May 2010 and August 2014, a total of 41 STEMI patients treated by either G2-DES (n = 26; everolimus-eluting stent [EES]: n = 15, zotarolimus-eluting stent [ZES]: n = 11) or BMS (n = 15) and, with multivessel disease requiring additional percutaneous coronary intervention (PCI), were prospectively enrolled. Optical coherence tomography (OCT) imaging was performed at 1 month after stent implantation.

RESULTS

Baseline clinical characteristics, except for age (61.5 ± 9.3 vs 69.3 ± 9.8, P = 0.01, t test), were comparable between patients with drug-eluting stent (DES) and BMS. The incidence of residual thrombus after the stent implantation for STEMI was comparable between DES and BMS (7.7% vs 6.7%, P = 0.88, χ 2 test). At 1 month, thrombus burden, defined as the mean thrombus area divided by the mean lumen area, was significantly smaller with DES than with BMS (median interquartile range (IQR), 1.2 (0.0, 1.0) vs 1.2 (0.0, 2.2), P = 0.04, Mann-Whitney U test), despite a similar percentage of malapposed (median (IQR), 6.2 (2.4, 9.0) vs 2.6 (0.0, 5.8)%, P = 0.07, Mann-Whitney U test) or uncovered struts (median (IQR), 6.8 (1.8, 13.1) vs 6.14 (2.8, 18.5)%, P = 0.45, Mann-Whitney U test). No significant difference in thrombus burden was observed between EES and ZES.

CONCLUSIONS

Thrombus burden was significantly smaller with DES than with BMS at 1-month follow-up in STEMI cases, although the percentage of malapposed or uncovered struts was similar between the groups. This may partly explain the lower rate of acute and subacute stent thrombosis in G2-DES that has previously been reported in the literature.

Percutaneous coronary and structural interventions in women: a position statement from the EAPCI Women Committee

Several expert documents on sex-based differences in interventional outcomes are now available, however this is the first position paper from the EAPCI Women Committee discussing the potential influence of sex in the percutaneous treatment of coronary and structural heart disease. Despite the misconception that coronary artery disease is a 'man's disease', contemporary data shows a growing incidence in women. However, women are under-represented in randomised coronary clinical trials (~25%). The generalisation of such studies is therefore problematic in decision-making for females undergoing coronary intervention. Differences in pathophysiology between sexes exist, highlighting the need for greater awareness amongst healthcare professionals to enable best evidence-based therapies for women as well as for men. Reassuringly, women represent half of the population included in transcatheter aortic valve implantation clinical trials and may actually benefit more. Growing evidence is also emerging for other interventional atrial procedures which may well be advantageous to women. Awareness of sex disparities is increasing, and we must all work collaboratively within our profession to ensure we provide effective care for all patients with heart disease. The EAPCI Women Committee aim to highlight such issues through this position paper and through visibility within the interventional community.

[MINOCA-myocardial infarction with non-obstructive coronary arteries]

In recent years it has been observed with increasing interest that there is a group of patients with electrocardiographic and laboratory features of myocardial infarction (MI) but no obstructive coronary artery disease (<50% diameter stenosis). For this entity the term myocardial infarction with non-obstructive coronary arteries (MINOCA) has been coined. The prevalence of MINOCA is estimated to be 6-9% among patients diagnosed with MI and it is more common in women than men as well as in patients presenting with NSTEMI than in those presenting with STEMI. The MINOCA is a working diagnosis that requires a further diagnostic work-up by invasive techniques, such as intravascular ultrasound (IVUS) and optical coherence tomography (OCT) or non-invasive imaging with cardiac magnetic resonance imaging (CMRI). When it is ascertained that obstructive coronary artery disease has not been inadvertently overlooked, other coronary disorders, such as plaque rupture or erosion, thrombosis, dissection, spasms or microvascular dysfunction should be evaluated. Furthermore, myocarditis or tako-tsubo cardiomyopathy should be excluded by CMRI as non-coronary causes. The further treatment and prognosis of patients with MINOCA depend on the underlying cause and the final diagnosis.

Plaque erosion versus rupture characterization by optical frequency domain imaging before and after coronary stenting following successful fibrinolysis for ST-segment elevation myocardial infarction

Intracoronary thrombus burden affects the quality of myocardial reperfusion in the setting of ST-elevation myocardial infarction (STEMI). We aimed to study the characteristics of the plaque and thrombus assessed by intracoronary optical frequency domain imaging (OFDI) according to the presence of plaque rupture or erosion in STEMI patients treated with successful fibrinolysis. Pre-stenting thrombus and post-stenting atherothrombotic burden were compared between plaque rupture and erosion. Twenty-seven consecutive patients were included: 17 (63%) had OFDI-plaque rupture and 10 (37%) had OFDI-erosion. Thrombus volume and burden were significantly higher in case of rupture compared to erosion at baseline (13.4 ± 18.4 vs 2.8 ± 2.3 mm³; p = 0.03 and 33.8 ± 17.5 vs 17.5 ± 9.9%; p = 0.007, respectively). In the rupture group, the core of the thrombus consisted dominantly of red thrombus evenly distributed along the entire culprit plaque. In the erosion group, it consisted dominantly of white thrombus with a focal distribution near the minimal lumen area zone. After stenting, the atherothrombotic volume, burden and its distribution, as well as angiographic estimators of myocardial reperfusion were similar between groups. Our study showed that pre-PCI thrombus amount, typesetting and distribution are mainly linked to the underlying mechanism of STEMI. After stenting, the atherothrombotic burden and its distribution were similar between the groups.

Clozapine-Induced Myocarditis or Acute Coronary Syndrome? Optical Coherence Tomography to the Rescue

Chest pain and troponin elevation may be due to an acute coronary syndrome, myocarditis, acute cardiomyopathy, or other less common conditions. Management differs depending on the aetiology, and the pathophysiologic diagnosis has direct implications on treatment and patient outcomes. History and clinical examination is supplemented by selected investigations including the electrocardiogram, chest X-ray, echocardiography, coronary angiography, and even myocardial perfusion scintigraphy or cardiac magnetic resonance imaging. Intravascular imaging can provide important insights into the underlying mechanism of acute coronary syndromes, especially when angiography is ambiguous.

CVIT expert consensus document on primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) in 2018

While primary percutaneous coronary intervention (PCI) has significantly contributed to improve the mortality in patients with ST segment elevation myocardial infarction even in cardiogenic shock, primary PCI is a standard of care in most of Japanese institutions. Whereas there are high numbers of available facilities providing primary PCI in Japan, there are no clear guidelines focusing on procedural aspect of the standardized care. Whilst updated guidelines for the management of acute myocardial infarction were recently published by European Society of Cardiology, the following major changes are indicated; (1) radial access and drug-eluting stent over bare metal stent were recommended as Class I indication, and (2) complete revascularization before hospital discharge (either immediate or staged) is now considered as Class IIa recommendation. Although the primary PCI is consistently recommended in recent and previous guidelines, the device lag from Europe, the frequent usage of coronary imaging modalities in Japan, and the difference in available medical therapy or mechanical support may prevent direct application of European guidelines to Japanese population. The Task Force on Primary Percutaneous Coronary Intervention of the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT) has now proposed the expert consensus document for the management of acute myocardial infarction focusing on procedural aspect of primary PCI.

Roles of PAD4 and NETosis in Experimental Atherosclerosis and Arterial Injury: Implications for Superficial Erosion

RATIONALE

Neutrophils likely contribute to the thrombotic complications of human atheromata. In particular, neutrophil extracellular traps (NETs) could exacerbate local inflammation and amplify and propagate arterial intimal injury and thrombosis. PAD4 (peptidyl arginine deiminase 4) participates in NET formation, but an understanding of this enzyme's role in atherothrombosis remains scant.

OBJECTIVE

This study tested the hypothesis that PAD4 and NETs influence experimental atherogenesis and in processes implicated in superficial erosion, a form of plaque complication we previously associated with NETs.

METHODS AND RESULTS

Bone marrow chimeric Ldlr deficient mice reconstituted with either wild-type or PAD4-deficient cells underwent studies that assessed atheroma formation or procedures designed to probe mechanisms related to superficial erosion. PAD4 deficiency neither retarded fatty streak formation nor reduced plaque size or inflammation in bone marrow chimeric mice that consumed an atherogenic diet. In contrast, either a PAD4 deficiency in bone marrow-derived cells or administration of DNaseI to disrupt NETs decreased the extent of arterial intimal injury in mice with arterial lesions tailored to recapitulate characteristics of human atheroma complicated by erosion.

CONCLUSIONS

These results indicate that PAD4 from bone marrow-derived cells and NETs do not influence chronic experimental atherogenesis, but participate causally in acute thrombotic complications of intimal lesions that recapitulate features of superficial erosion.

Nonculprit Plaque Characteristics in Patients With Acute Coronary Syndrome Caused by Plaque Erosion vs Plaque Rupture: A 3-Vessel Optical Coherence Tomography Study

Importance

Patients with culprit plaque rupture are known to have pancoronary plaque vulnerability. However, the characteristics of nonculprit plaques in patients with acute coronary syndromes caused by plaque erosion are unknown.

Objective

To investigate the nonculprit plaque phenotype in patients with acute coronary syndrome according to culprit plaque pathology (erosion vs rupture) by 3-vessel optical coherence tomography imaging.

Design, Setting, and Participants

In this observational cohort study, between August 2010 and May 2014, 82 patients with acute coronary syndrome who underwent preintervention optical coherence tomography imaging of all 3 major epicardial coronary arteries were enrolled at the Massachusetts General Hospital Optical Coherence Tomography Registry database. Analysis of the data was conducted between November 2016 and July 2017. Patients were classified into 2 groups based on the culprit lesion pathology: 17 patients with culprit plaque erosion and 34 patients with culprit plaque rupture. Thirty-one patients with the absence of culprit rupture or erosion were excluded from further analysis.

Exposures

Preintervention 3-vessel optical coherence tomography imaging.

Main Outcomes and Measures

Plaque characteristics at the culprit and nonculprit lesions evaluated by optical coherence tomography.

Results

In 51 patients (37 men; mean age, 58.7 years), the characteristics of 51 culprit plaques and 216 nonculprit plaques were analyzed. In patients with culprit erosion, the mean (SD) number of nonculprit plaques per patient was smaller (3.4 [1.9] in erosion vs 4.7 [2.1] in rupture, P = .05). Patient-based analysis showed that none of 17 patients with culprit plaque erosion had nonculprit plaque rupture, whereas 26% of the patients (9 of 34) with culprit plaque rupture had nonculprit plaque rupture (P = .02). Plaque-based analysis showed that, compared with the culprit rupture group (n = 158), the culprit erosion group (n = 58) had lower prevalence of plaque rupture (0% vs 8%; P < .001), macrophage accumulation (29% vs 53%; P = .01), microvessels (21% vs 42%; P = .003), and spotty calcium (5% vs 22%; P = .006) in the nonculprit lesions. The prevalence of lipid-rich plaque, thin-cap fibroatheroma, and thrombus did not differ between the groups.

Conclusions and Relevance

Compared with those with culprit plaque rupture, patients with acute coronary syndrome caused by culprit plaque erosion had a smaller number of nonculprit plaques and the lower levels of panvascular instability, affirming that distinct pathophysiologic mechanisms operate in plaque erosion and plaque rupture.

Advances in Intravascular Imaging: New Insights into the Vulnerable Plaque from Imaging Studies

The term “vulnerable plaque” denotes the plaque characteristics that are susceptible to coronary thrombosis. Previous post-mortem studies proposed 3 major mechanisms of coronary thrombosis: plaque rupture, plaque erosion, and calcified nodules. Of those, characteristics of rupture-prone plaque have been extensively studied. Pathology studies have identified the features of rupture-prone plaque including thin fibrous cap, large necrotic core, expansive vessel remodeling, inflammation, and neovascularization. Intravascular imaging modalities have emerged as adjunctive tools of angiography to identify vulnerable plaques. Multiple devices have been introduced to catheterization laboratories to date, including intravascular ultrasound (IVUS), virtual-histology IVUS, optical coherence tomography (OCT), coronary angioscopy, and near-infrared spectroscopy. With the use of these modalities, our understanding of vulnerable plaque has rapidly grown over the past several decades. One of the goals of intravascular imaging is to better predict and prevent future coronary events, for which prospective observational data is still lacking. OCT delineates microstructures of plaques, whereas IVUS visualizes macroscopic vascular structures. Specifically, plaque erosion, which has been underestimated in clinical practice, is gaining an interest due to the potential of OCT to make an in vivo diagnosis. Another potential future avenue for intravascular imaging is its use to guide treatment. Feasibility of tailored therapy for acute coronary syndromes (ACS) guided by OCT is under investigation. If it is proven to be effective, it may potentially lead to major shift in the management of millions of patients with ACS every year.

Acute Coronary Syndromes: The Way Forward From Mechanisms to Precision Treatment

Well into the 21st century, we still triage acute myocardial infarction on the basis of the presence or absence of ST-segment elevation, a century-old technology. Meanwhile, we have learned a great deal about the pathophysiology and mechanisms of acute coronary syndromes (ACS) at the clinical, pathological, cellular, and molecular levels. Contemporary imaging studies have shed new light on the mechanisms of ACS. This review discusses these advances and their implications for clinical management of the ACS for the future. Plaque rupture has dominated our thinking about ACS pathophysiology for decades. However, current evidence suggests that a sole focus on plaque rupture vastly oversimplifies this complex collection of diseases and obscures other mechanisms that may mandate different management strategies. We propose segmenting coronary artery thrombosis caused by plaque rupture into cases with or without signs of concomitant inflammation. This distinction may have substantial therapeutic implications as direct anti-inflammatory interventions for atherosclerosis emerge. Coronary artery thrombosis caused by plaque erosion may be on the rise in an era of intense lipid lowering. Identification of patients with of ACS resulting from erosion may permit a less invasive approach to management than the current standard of care. We also now recognize ACS that occur without apparent epicardial coronary artery thrombus or stenosis. Such events may arise from spasm, microvascular disease, or other pathways. Emerging management strategies may likewise apply selectively to this category of ACS. We advocate this more mechanistic approach to the categorization of ACS to provide a framework for future tailoring, triage, and therapy for patients in a more personalized and precise manner.

Mechanisms of erosion of atherosclerotic plaques

PURPOSE OF REVIEW

The present review explores the mechanisms of superficial intimal erosion, a common cause of thrombotic complications of atherosclerosis.

RECENT FINDINGS

Human coronary artery atheroma that give rise to thrombosis because of erosion differ diametrically from those associated with fibrous cap rupture. Eroded lesions characteristically contain few inflammatory cells, abundant extracellular matrix, and neutrophil extracellular traps (NETs). Innate immune mechanisms such as engagement of Toll-like receptor 2 (TLR2) on cultured endothelial cells can impair their viability, attachment, and ability to recover a wound. Hyaluronan fragments may serve as endogenous TLR2 ligands. Mouse experiments demonstrate that flow disturbance in arteries with neointimas tailored to resemble features of human eroded plaques disturbs endothelial cell barrier function, impairs endothelial cell viability, recruits neutrophils, and provokes endothelial cells desquamation, NET formation, and thrombosis in a TLR2-dependent manner.

SUMMARY

Mechanisms of erosion have received much less attention than those that provoke plaque rupture. Intensive statin treatment changes the characteristic of plaques that render them less susceptible to rupture. Thus, erosion may contribute importantly to the current residual burden of risk. Understanding the mechanisms of erosion may inform the development and deployment of novel therapies to combat the remaining atherothrombotic risk in the statin era.

Tissue characterization with depth-resolved attenuation coefficient and backscatter term in intravascular optical coherence tomography images

An important application of intravascular optical coherence tomography (IVOCT) for atherosclerotic tissue analysis is using it to estimate attenuation and backscatter coefficients. This work aims at exploring the potential of the attenuation coefficient, a proposed backscatter term, and image intensities in distinguishing different atherosclerotic tissue types with a robust implementation of depth-resolved (DR) approach. Therefore, the DR model is introduced to estimate the attenuation coefficient and further extended to estimate the backscatter-related term in IVOCT images, such that values can be estimated per pixel without predefining any delineation for the estimation. In order to exclude noisy regions with a weak signal, an automated algorithm is implemented to determine the cut-off border in IVOCT images. The attenuation coefficient, backscatter term, and the image intensity are further analyzed in regions of interest, which have been delineated referring to their pathology counterparts. Local statistical values were reported and their distributions were further compared with a two-sample t-test to evaluate the potential for distinguishing six types of tissues. Results show that the IVOCT intensity, DR attenuation coefficient, and backscatter term extracted with the reported implementation are complementary to each other on characterizing six tissue types: mixed, calcification, fibrous, lipid-rich, macrophages, and necrotic core.

Association of Platelet to lymphocyte ratio with non-culprit atherosclerotic plaque vulnerability in patients with acute coronary syndrome: an optical coherence tomography study

Background

The platelet to lymphocyte ratio (PLR), an indirect inflammatory biomarker, has been recently demonstrated to be associated with severity of coronary artery disease. In the present study, we sought to investigate whether PLR is associated with vulnerable plaque characteristics of non-culprit lesions in patients with acute coronary syndrome (ACS).

Methods

The patients in our study were divided into two groups (high PLR group and low PLR group). A total of 119 non-culprit plaques from 71 patients with ACS were assessed by optical coherence tomography (OCT).

Results

The non-culprit plaques in high PLR group exhibited thinner fibrous cap thickness (FCT) (88.60 ± 44.70 vs. 119.28 ± 50.22 μm, P = 0.001), greater maximum lipid arc (271.73 ± 71.66 vs. 240.60 ± 76.69°, P = 0.027) and increased incidence of thin-cap fibroatheroma (TCFA) (34.0% vs. 15.9%, P = 0.022) compared with those in low PLR group. Meanwhile, PLR was negatively associated with FCT (r = −0.329, P < 0.001). Furthermore, multivariate regression analysis showed that PLR [OR: 1.023 (95% CI: 1.005–1.041), P = 0.012] and LDL-C [OR: 1.892 (95% CI: 1.106–3.239), P = 0.020] were significant predictors of TCFA.

Conclusions

High level of PLR may be associated with vulnerable plaque features of non-culprit lesions in patients with ACS. PLR, a cheap and easily available index, may surve as a useful inflammatory marker in reflecting plaque vulnerability.

Review. Automatic Segmentation Techniques of the Coronary Artery Using CT Images in Acute Coronary Syndromes

Coronary artery disease represents one of the leading reasons of death worldwide, and acute coronary syndromes are their most devastating consequences. It is extremely important to identify the patients at risk for developing an acute myocardial infarction, and this goal can be achieved using noninvasive imaging techniques. Coronary computed tomography angiography (CCTA) is currently one of the most reliable methods used for assessing the coronary arteries; however, its use in emergency settings is sometimes limited due to time constraints. This paper presents the main characteristics of plaque vulnerability, the role of CCTA in the assessment of vulnerable plaques, and automatic segmentation techniques of the coronary artery tree based on CT angiography images. A detailed inventory of existing methods is given, representing the state-of-the-art of computational methods applied in vascular system segmentation, focusing on the current applications in acute coronary syndromes.

Stenting versus non-stenting treatment of intermediate stenosis culprit lesion in acute ST-segment elevation myocardial infarction: a multicenter randomized clinical trial

Background

The benefit/risk ratio of stenting in acute ST-segment elevation myocardial infarction (STEMI) patients with single vessel intermediate stenosis culprit lesions merits further study, therefore the subject of the present study.

Methods and results

It was a prospective, multicenter, randomized controlled trial. Between April 2012 and July 2015, 399 acute STEMI patients with single vessel disease and intermediate (40%–70%) stenosis of the culprit lesion before or after aspiration thrombectomy and/or intracoronary tirofiban (15 µg/kg) were enrolled and were randomly assigned (1: 1) to stenting group (n = 201) and non-stenting group (n = 198). In stenting group, patients received pharmacologic therapy plus standard percutaneous coronary intervention (PCI) with stent implantation. In non-stenting group, patients received pharmacologic therapy and PCI (thrombectomy), but without dilatation or stenting. Primary endpoint was 12-month rate of major adverse cardiac and cerebrovascular events (MACCE), a composite of cardiac death, non-fatal myocardial infarction (MI), repeat revascularization and stroke. Secondary endpoints were 12-month rates of all cause death, ischemia driven admission and bleeding complication. Median follow-up time was 12.4 ± 3.1 months. At 12 months, MACCE occurred in 8.0% of the patients in stenting group, as compared with 15.2% in the non-stenting group (adjusted HR: 0.42, 95% CI: 0.19–0.89, P = 0.02). The stenting group had lower non-fatal MI rate than non-stenting group, (1.5% vs. 5.5%, P = 0.03). The two groups shared similar cardiac death, repeat revascularization, stroke, all cause death, ischemia driven readmission and bleeding rates at 12 months.

Conclusions

Stent implantation had better efficacy and safety in reducing MACCE risks among acute STEMI patients with single vessel intermediate stenosis culprit lesions.

Inflammatory Differences in Plaque Erosion and Rupture in Patients With ST-Segment Elevation Myocardial Infarction

Background

Plaque erosion causes 30% of ST‐segment elevation myocardial infarctions, but the underlying cause is unknown. Inflammatory infiltrates are less abundant in erosion compared with rupture in autopsy studies. We hypothesized that erosion and rupture are associated with significant differences in intracoronary cytokines in vivo.

Methods and Results

Forty ST‐segment elevation myocardial infarction patients with <6 hours of chest pain were classified as ruptured fibrous cap (RFC) or intact fibrous cap (IFC) using optical coherence tomography. Plasma samples from the infarct‐related artery and a peripheral artery were analyzed for expression of 102 cytokines using arrays; results were confirmed with ELISA. Thrombectomy samples were analyzed for differential mRNA expression using quantitative real‐time polymerase chain reaction. Twenty‐three lesions were classified as RFC (58%), 15 as IFC (38%), and 2 were undefined (4%). In addition, 12% (12 of 102) of cytokines were differentially expressed in both coronary and peripheral plasma. I‐TAC was preferentially expressed in RFC (significance analysis of microarrays adjusted P<0.001; ELISA IFC 10.2 versus RFC 10.8 log₂ pg/mL; P=0.042). IFC was associated with preferential expression of epidermal growth factor (significance analysis of microarrays adjusted P<0.001; ELISA IFC 7.42 versus RFC 6.63 log₂ pg/mL, P=0.036) and thrombospondin 1 (significance analysis of microarrays adjusted P=0.03; ELISA IFC 10.4 versus RFC 8.65 log₂ ng/mL, P=0.0041). Thrombectomy mRNA showed elevated I‐TAC in RFC (P=0.0007) epidermal growth factor expression in IFC (P=0.0264) but no differences in expression of thrombospondin 1.

Conclusions

These results demonstrate differential intracoronary cytokine expression in RFC and IFC. Elevated thrombospondin 1 and epidermal growth factor may play an etiological role in erosion.

Flow Perturbation Mediates Neutrophil Recruitment and Potentiates Endothelial Injury via TLR2 in Mice: Implications for Superficial Erosion

RATIONALE

Superficial erosion currently causes up to a third of acute coronary syndromes; yet, we lack understanding of its mechanisms. Thrombi because of superficial intimal erosion characteristically complicate matrix-rich atheromata in regions of flow perturbation.

OBJECTIVE

This study tested in vivo the involvement of disturbed flow and of neutrophils, hyaluronan, and Toll-like receptor 2 ligation in superficial intimal injury, a process implicated in superficial erosion.

METHODS AND RESULTS

In mouse carotid arteries with established intimal lesions tailored to resemble the substrate of human eroded plaques, acute flow perturbation promoted downstream endothelial cell activation, neutrophil accumulation, endothelial cell death and desquamation, and mural thrombosis. Neutrophil loss-of-function limited these findings. Toll-like receptor 2 agonism activated luminal endothelial cells, and deficiency of this innate immune receptor decreased intimal neutrophil adherence in regions of local flow disturbance, reducing endothelial cell injury and local thrombosis (P<0.05).

CONCLUSIONS

These results implicate flow disturbance, neutrophils, and Toll-like receptor 2 signaling as mechanisms that contribute to superficial erosion, a cause of acute coronary syndrome of likely growing importance in the statin era.

Late breaking trials of 2016 in coronary artery disease: Commentary covering SCAI, ACC, TCT, EuroPCR, ESC, and AHA

The SCAI Publications Committee and Emerging Leadership Mentorship (ELM) Fellows concisely summarize and provide context on the most important coronary trials presented at large international meetings in 2016, including SCAI, ACC, TCT, EuroPCR, ESC, and AHA. The intent is to allow quick assimilation of trial results into interventional practice, and enable busy interventional cardiologists to stay up to date. © 2017 Wiley Periodicals, Inc.

Management and Outcome of Patients With Acute Coronary Syndrome Caused by Plaque Rupture Versus Plaque Erosion: An Intravascular Optical Coherence Tomography Study

Background

Plaque rupture and erosion are the 2 most common mechanisms for acute coronary syndromes. However, the outcome of these 2 distinct pathologies in patients with acute coronary syndromes has never been studied.

Methods and Results

We retrospectively studied 141 patients with acute coronary syndromes who underwent optical coherence tomography (OCT) imaging of the culprit lesion prior to stenting from the Massachusetts General Hospital OCT Registry. Management (stent versus no stent), poststent OCT findings, and outcomes were compared. Among the 141 culprit lesions, rupture was found in 79 (56%) patients and erosion in 62 (44%). Stent implantation was performed in 77 (97.5%) patients with rupture versus 49 (79.0%) in those with erosion (P<0.001). Immediately after percutaneous coronary intervention, OCT showed a higher incidence of malapposition (37.5% versus 7.3%, P<0.001), thrombus (59.4% versus 14.6%, P<0.001), and protrusion (93.8% versus 73.2%, P=0.008) in the rupture group compared with the erosion group. Plaque rupture was associated with a higher incidence of no reflow or slow flow and distal embolization. Although cardiac event rates were comparable between the two groups at the 1‐year follow‐up, none of the erosion patients who were treated conservatively without stenting had adverse cardiac events.

Conclusions

Unfavorable poststent OCT findings were more frequent in rupture patients compared with erosion patients. A subset of erosion patients who were treated conservatively without stenting remained free of adverse cardiac events for up to 1 year.