Eroded Versus Ruptured Plaques at the Culprit Site of STEMI: In Vivo Pathophysiological Features and Response to Primary PCI

Spontaneous coronary artery dissection: review, case report and analysis of COVID-19-related cases

Spontaneous coronary artery dissection (SCAD) accounts for 1-4% of all acute coronary syndromes (ACS). Since the first description in 1931, our understanding of the disease has evolved; however, its pathophysiology and management are still a matter of debate. SCAD typically occurs in a middle-aged woman with no or few traditional cardiovascular risk factors. Two hypotheses have been proposed to explain the pathophysiology depending on the primary event: an intimal tear in the "inside-out" hypothesis and a spontaneous hemorrhage from the vasa vasorum in the "outside-in" hypothesis. Etiology appears to be multifactorial: different predisposing and precipitating factors have been identified. Coronary angiography is the gold standard for the diagnosis of SCAD. Current recommendations on the treatment of SCAD patients are based on expert opinions: a conservative strategy is preferred in hemodynamically stable SCAD patients, while urgent revascularization should be considered in hemodynamically unstable patients. Eleven cases of SCAD in COVID-19 patients have already been described: although the exact pathophysiological mechanism remains unclear, COVID-19-related SCAD is considered a combination of significant systemic inflammatory response and localized vascular inflammation. We present a literature review of SCAD, and we report an unpublished case of SCAD in a COVID-19 patient.

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

ABSTRACT

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

Blood Flow Energy Identifies Coronary Lesions Culprit of Future Myocardial Infarction

The present study establishes a link between blood flow energy transformations in coronary atherosclerotic lesions and clinical outcomes. The predictive capacity for future myocardial infarction (MI) was compared with that of established quantitative coronary angiography (QCA)-derived predictors. Angiography-based computational fluid dynamics (CFD) simulations were performed on 80 human coronary lesions culprit of MI within 5 years and 108 non-culprit lesions for future MI. Blood flow energy transformations were assessed in the converging flow segment of the lesion as ratios of kinetic and rotational energy values (KER and RER, respectively) at the QCA-identified minimum lumen area and proximal lesion sections. The anatomical and functional lesion severity were evaluated with QCA to derive percentage area stenosis (%AS), vessel fractional flow reserve (vFFR), and translesional vFFR (ΔvFFR). Wall shear stress profiles were investigated in terms of topological shear variation index (TSVI). KER and RER predicted MI at 5 years (AUC = 0.73, 95% CI 0.65-0.80, and AUC = 0.76, 95% CI 0.70-0.83, respectively; p < 0.0001 for both). The predictive capacity for future MI of KER and RER was significantly stronger than vFFR (p = 0.0391 and p = 0.0045, respectively). RER predictive capacity was significantly stronger than %AS and ΔvFFR (p = 0.0041 and p = 0.0059, respectively). The predictive capacity for future MI of KER and RER did not differ significantly from TSVI. Blood flow kinetic and rotational energy transformations were significant predictors for MI at 5 years (p < 0.0001). The findings of this study support the hypothesis of a biomechanical contribution to the process of plaque destabilization/rupture leading to MI.

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

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

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSION

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

Comparisons of Patients Living Alone versus Living with Others in Acute Coronary Syndrome

We aimed to examine the relationship of living arrangements (i.e., living alone or living with others) with background, clinical severity, preintervention culprit lesion plaque morphology, and clinical outcomes in patients with acute coronary syndrome (ACS). Among 1,683 consecutive patients with ACS, we retrospectively compared patients living alone ( n  = 318) versus living with others ( n  = 1,362). Optical coherence tomography (OCT) findings, which are high-resolution intracoronary imaging devices, were analyzed in patients with preintervention OCT and compared between patients living alone ( n  = 174) versus those living with others ( n  = 665). Older (median; 69 vs. 67 y, p  = 0.046) and female (31 vs. 17%, p  < 0.001) patients more frequently lived alone. Frequency of achieving a time interval of 6 hours or less from ACS onset to admission was lower in patients living alone (56 vs. 63%, p  = 0.022). Clinical presentation was more severe in patients living alone (Killip II/III/IV; 27 vs. 22%, p  = 0.029). Plaque morphology evaluated by OCT was similar between groups (plaque rapture; 48 vs. 48%, p  = 0.171). Kaplan-Meier analyses revealed higher rates of cardiac mortality during 2-year follow-up period in patients living alone [13.9 vs. 8.5%, hazard ratio (HR) 1.604, 95% confidence interval (CI) 1.112-2.313, p  = 0.010]. After traditional cardiovascular risk factors and clinical severity upon admission had been adjusted, living alone was an independent predictor of cardiac mortality in ACS patients (HR 1.582, 95% CI 1.056-2.371, p  = 0.026). Living alone was independently associated with 2-year cardiacmortality in ACS patients after adjusting for background and presentation and might be unrelated to the development of atherosclerosis.

The role of endothelial shear stress, shear stress gradient, and plaque topography in plaque erosion

BACKGROUND AND AIMS

Plaque erosion is a common underlying cause of acute coronary syndromes. The role of endothelial shear stress (ESS) and endothelial shear stress gradient (ESSG) in plaque erosion remains unknown. We aimed to determine the role of ESS metrics and maximum plaque slope steepness in plaques with erosion versus stable plaques.

METHODS

This analysis included 46 patients/plaques from TOTAL and COMPLETE trials and Brigham and Women's Hospital's database who underwent angiography and OCT. Plaques were divided into those with erosion (n = 24) and matched stable coronary plaques (n = 22). Angiographic views were used to generate a 3-D arterial reconstruction, with centerlines merged from angiography and OCT pullback. Local ESS metrics were assessed by computational fluid dynamics. Among plaque erosions, the up- and down-slope (Δ lumen area/frame) was calculated for each culprit plaque.

RESULTS

Compared with stable plaque controls, plaques with an erosion were associated with higher max ESS (8.3 ± 4.8 vs. 5.0 ± 1.9 Pa, p = 0.02) and max ESSG any direction (9.2 ± 7.5 vs. 4.3 ± 3.11 Pa/mm, p = 0.005). Proximal erosion was associated with a steeper plaque upslope while distal erosion with a steeper plaque downslope. Max ESS and Max ESSG any direction were independent factors in the development of plaque erosion (OR 1.32, 95%CI 1.06-1.65, p = 0.014; OR 1.22, 95% CI 1.03-1.45, p = 0.009, respectively).

CONCLUSIONS

In plaques with similar luminal stenosis, plaque erosion was strongly associated with higher ESS, ESS gradients, and plaque slope as compared with stable plaques. These data support that ESS and slope metrics play a key role in the development of plaque erosion and may help prognosticate individual plaques at risk for future erosion.

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

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

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.

Vascular Response After Everolimus-Eluting Stent in Acute Myocardial Infarction Caused by Calcified Nodule

BACKGROUND

Patients with acute myocardial infarction (AMI) caused by calcified nodules (CN) have worse clinical outcomes following primary percutaneous coronary intervention (PCI). This study investigated the late vascular response after everolimus-eluting stent (EES) implantation assessed by optical coherence tomography (OCT) in patients with AMI caused by CN, by comparing with plaque rupture (PR) and plaque erosion (PE).Methods and Results: Based on the OCT findings in AMI culprit lesions before PCI, a total of 141 patients were categorized into 3 groups (PR, PE, or CN), and the OCT findings immediately and 10 months after PCI were compared. The frequency of PR, PE, and CN was 85 (60%), 45 (32%), and 11 patients (8%), respectively. In the 10-month follow-up OCT, the frequency of lesions with uncovered struts and lesions with malapposed struts were highest in the CN group, followed by the PR and PE groups (82% vs. 52% vs. 40%, P=0.042 and 73% vs. 26% vs. 16%, P<0.001, respectively). The incidence of intra-stent thrombus, re-appearance of CN within the stent, and target lesion revascularization were higher in the CN group compared with the PR and PE groups (36% vs. 9% vs. 7%, P=0.028; 27% vs. 0% vs. 0%, P<0.001; and 18% vs. 2% vs. 2%, P=0.024, respectively).

CONCLUSIONS

Late arterial healing response at 10 months after EES implantation in the CN was worse compared with PR and PE in patients with AMI.

High-Risk Culprit Plaque Predicts Cardiovascular Outcomes Independently of Plaque Rupture in ST-Segment Elevation Myocardial Infarction: Insight From Optical Coherence Tomography

The present study explored the predictive value of culprit high-risk plaque (HRP) detected by optical coherence tomography (OCT) for predicting major adverse cardiovascular events (MACEs) in patients with ST-segment elevation myocardial infarction (STEMI). HRP was defined as the simultaneous presence of four criteria: minimum lumen area <3.5 mm², fibrous cap thickness <75 μm, lipid plaque with lipid arc extension >180°, and presence of macrophages. Patients (n = 274) were divided into non-HRP group (n = 206) and HRP group (n = 68). MACEs were defined as a composite of all-cause death, myocardial infarction, stroke, and revascularization. During a mean follow-up of 2.2 years, 47 (17.5%) MACEs were observed: 28 (13.6%) in the non-HRP group and 19 (27.9%) in the HRP group (log-rank P = .005). Patients with HRP were 2.05 times more likely to suffer from a MACE than those without HRP (hazards ratio: 2.05, 95% confidence interval: 1.04-4.02, P = .038); MACE risk was comparable between plaque rupture and plaque erosion. In conclusion, HRP was present in 24.8% of STEMI patients and associated with higher cardiovascular risk independent of plaque rupture, suggesting that HRP detected by OCT may help identify patients at high risk of future cardiac events.

Optical Coherence Tomography and Coronary Dissection: Precious Tool or Useless Surplus?

Spontaneous coronary artery dissection (SCAD) is a rare clinical condition, but frequently manifested as acute myocardial infarction. In this particular setting, in recent years, optical coherence tomography (OCT) has been established as a possible diagnostic method due to the high spatial resolution (10–20 μm), which can visualize the different layers of coronary vessels. OCT can better analyze the “binary” or double lumen morphology, typical of this entity. Furthermore, it can identify the entrance breach and the circumferential and longitudinal extension of the lesion. However, we have to emphasize that this technique is not free from complications. OCT could further aggravate a dissection or exacerbate a new intimal tear. Therefore, the use of OCT in the evaluation of SCAD should be defined by balancing the diagnostic benefits versus procedural risks. Moreover, we underline that as SCAD is a rare condition and OCT is a recently introduced technique in clinical practice, limited data is available in literature.

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

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

Layered Plaque Characteristics and Layer Burden in Acute Coronary Syndromes

Recently, layered plaque, an optical coherence tomography equivalent of healed plaque, has been gaining attention. However, detailed layered plaque characteristics including the burden of plaque layer have not been investigated. Patients with acute coronary syndromes who underwent preintervention optical coherence tomography imaging of culprit lesion were included. Layer index, a product of the mean layer arc and layer length, was correlated with the pattern of layer and culprit pathology. In addition, layer index was compared between culprit and nonculprit plaques. Finally, predictors for greater layer index were identified using general linear modeling. In 349 patients, 99 culprit plaques had layered phenotype (28.4%), whereas among 465 nonculprit plaques, 165 had layered pattern (35.5%). Layer index was greater in multilayer pattern versus single-layer pattern (1,688.5 vs 996.6, p <0.001), interrupted layer phenotype versus intact layer phenotype (1,276.5 vs 646.8, p <0.001), rupture versus erosion at culprit lesion (1,191.0 vs 861.8, p <0.001), and culprit versus nonculprit plaque (1,475.6 vs 983.4, p <0.001). The general linear modeling revealed that multilayer pattern (regression coefficient b [B] 7.332, p <0.001), interrupted layer phenotype (B 4.624, p <0.001), culprit lesion (B 2.792, p = 0.001), lipid-rich plaque (B 1.953, p = 0.032), and culprit plaque rupture (B: 1.943, p = 0.008) were the significant predictors for greater layer index. In conclusion, layer index (burden of layered plaque) was greater in multilayer pattern, interrupted layer phenotype, at culprit plaque, lipid-rich plaque, and in cases with culprit plaque rupture.

Monocyte-Platelet Aggregates Triggered by CD31 Molecule in Non-ST Elevation Myocardial Infarction: Clinical Implications in Plaque Rupture

Despite the recent innovations in cardiovascular care, atherothrombosis is still a major complication of acute coronary syndromes (ACS). We evaluated the involvement of the CD31 molecule in thrombotic risk through the formation of monocyte-platelet (Mo-Plt) aggregates in patients with ACS with no-ST-segment elevation myocardial infarction (NSTEMI) on top of dual anti-platelet therapy (DAPT). We enrolled 19 control (CTRL) subjects, 46 stable angina (SA), and 86 patients with NSTEMI, of which, 16 with Intact Fibrous Cap (IFC) and 19 with Ruptured Fibrous Cap (RFC) as assessed by the Optical Coherence Tomography (OCT). The expression of CD31 on monocytes and platelets was measured. Following the coronary angiography, 52 NSTEMIs were further stratified according to thrombus grade (TG) evaluation. Finally, a series of ex vivo experiments verified whether the CD31 participates in Mo-Plt aggregate formation. In patients with NSTEMI, CD31 was reduced on monocytes and was increased on platelets, especially in NSTEMI presented with RFC plaques compared to those with IFC lesions, and in patients with high TG compared to those with zero/low TG. Ex vivo experiments documented an increase in Mo-Plt aggregates among NSTEMI, which significantly decreased after the CD31 ligation, particularly in patients with RFC plaques. In NSTEMI, CD31 participates in Mo-Plt aggregate formation in spite of optimal therapy and DAPT, suggesting the existence of alternative thrombotic pathways, as predominantly displayed in patients with RFC.

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.

Helicopter emergency medical service for patients with acute coronary syndrome: selection validity and impact on clinical outcomes

Helicopter emergency medical service (HEMS) has the potential to improve prognosis for acute coronary syndrome (ACS). However, adequacy and effectiveness of HEMS have not been fully evaluated. A total of 862 ACS patients transferred by emergency medical services were divided into two groups: patients transferred by HEMS (n = 171) or by ground ambulance (GA; n = 691). Among them, angiography images for 718 patients (149 in HEMS and 569 in GA group) and optical coherence tomography (OCT) images for 374 patients (75 in HEMS and 299 in GA groups) were analyzed. Additional analysis to compare 2-year cardiac mortality between groups was conducted following propensity score matching to adjust for inter-group differences. ST-segment elevation myocardial infarction (81% vs. 66%, p < 0.001) and cardiogenic shock (Killip IV; 20% vs. 10%, p < 0.001) at admission were more prevalent in HEMS than GA group. Time from admission to balloon angioplasty was shorter in HEMS group (median 54 min vs. 69 min, p < 0.001). Antegrade coronary flow was worse in HEMS group (TIMI flow grade 0 or 1; 68% vs. 51%, p < 0.001). Plaque rupture was more frequently detected by OCT in HEMS group (68% vs. 49%, p = 0.029). Following propensity score matching, the incidence of cardiac death was significantly lower in HEMS group (6.3% vs. 14.9%, p = 0.019). In conclusion, severe ACS patients requiring early reperfusion were appropriately triaged and transferred more rapidly by HEMS. Lower mortality in HEMS group after propensity score matching suggests that HEMS may improve cardiac mortality in ACS patients.

Immune Mechanisms of Plaque Instability

Inflammation crucially drives atherosclerosis from disease initiation to the emergence of clinical complications. Targeting pivotal inflammatory pathways without compromising the host defense could compliment therapy with lipid-lowering agents, anti-hypertensive treatment, and lifestyle interventions to address the substantial residual cardiovascular risk that remains beyond classical risk factor control. Detailed understanding of the intricate immune mechanisms that propel plaque instability and disruption is indispensable for the development of novel therapeutic concepts. In this review, we provide an overview on the role of key immune cells in plaque inception and progression, and discuss recently identified maladaptive immune phenomena that contribute to plaque destabilization, including epigenetically programmed trained immunity in myeloid cells, pathogenic conversion of autoreactive regulatory T-cells and expansion of altered leukocytes due to clonal hematopoiesis. From a more global perspective, the article discusses how systemic crises such as acute mental stress or infection abruptly raise plaque vulnerability and summarizes recent advances in understanding the increased cardiovascular risk associated with COVID-19 disease. Stepping outside the box, we highlight the role of gut dysbiosis in atherosclerosis progression and plaque vulnerability. The emerging differential role of the immune system in plaque rupture and plaque erosion as well as the limitations of animal models in studying plaque disruption are reviewed.

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.

Spontaneous Coronary Artery Dissection: A Rare Event?

Spontaneous coronary artery dissection is an infrequent cause of acute coronary syndrome with comparable clinical features. Previously considered a rare disease, recent scientific interest has revealed spontaneous coronary artery dissection as an important differential diagnosis of acute coronary syndrome, especially in young women, during pregnancy or postpartum, and in patients with fibromuscular dysplasia or other arteriopathies. However, there remain many uncertainties regarding pathophysiology, risk factors, acute treatment, and optimal long-term management. The aim of this review is to summarize current scientific evidence on epidemiology, management, and outcomes.

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.

Culprit lesion characteristics in very young patients with acute coronary syndrome: An optical coherence tomography study

OBJECTIVE

The concept of managing patients on the basis of culprit lesion characteristics is emerging. Atherosclerotic plaques are reported to be rare in young patients presenting with acute coronary syndrome (ACS). We aimed to assess culprit lesion characteristics in very young patients presenting with ACS by optical coherence tomography (OCT).

METHODS

This was a prospective, single-center, open-label, observational study. Patients aged 35 years or less with ACS who underwent invasive coronary angiography and OCT were studied.

RESULTS

Of the 43 patients, 22 (51.2%) had plaque rupture, 16 (37.2%) had plaque erosion, and five (11.6%) had no specific lesion character. Plaque was fibroatheromatous in 34 (79.1%) patients and fibrous in seven (16.3%). Plaque was not found in two (4.7%) patients; of these, one (2.3%) had left anterior descending coronary artery bridging, and one (2.3%) had intimal dissection without any plaque. Plaque rupture was more commonly associated with fibroatheromatous plaques, whereas plaque erosion was more commonly associated with fibrous plaque (p=0.010).

CONCLUSION

Although plaque rupture and plaque erosion occurred at the same rate as seen in patients of all ages, calcified nodule as a culprit lesion was not found in young patients. Majority of the patients had plaque rupture and plaque erosion with fibroatheromatous plaque, signifying the occurrence of established coronary artery disease in very young patients of Southeast Asia.

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

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

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

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Supplementary Information

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

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

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

Laser Vaporization of Intracoronary Thrombus and Identifying Plaque Morphology in ST-Segment Elevation Myocardial Infarction as Assessed by Optical Coherence Tomography

Objectives

We evaluated the thrombus-vaporizing effect of excimer laser coronary angioplasty (ELCA) in patients with ST-segment elevation myocardial infarction (STEMI) by optical coherence tomography (OCT).

Background

Larger intracoronary thrombus elevates the risk of interventional treatment and mortality in patients with STEMI.

Methods

A total of 92 patients with STEMI who presented within 24 hours from the onset and underwent ELCA following manual aspiration thrombectomy (MT) were analyzed.

Results

The mean baseline thrombolysis in myocardial infarction flow grade was 0.4 ± 0.6, which subsequently improved to 2.3 ± 0.7 after MT (p < 0.0001) and 2.7 ± 0.5 after ELCA (p=0.0001). The median residual thrombus volume after MT was 65.7 mm³, which significantly reduced to 47.5 mm³ after ELCA (p < 0.0001). Plaque rupture was identified by OCT in only 22 cases (23.9%) after MT, but was distinguishable in 36 additional cases after ELCA (total: 58 cases; 63.0%). Ruptured lesions contained a higher proportion of red thrombus than nonruptured lesions (75.9% vs. 43.3%, p=0.001). Significantly larger thrombus burden after MT (69.6 mm³ vs. 56.3 mm³, p < 0.05) and greater thrombus reduction by ELCA (21.2 mm³ vs. 11.8 mm³, p < 0.01) were observed in ruptured lesions than nonruptured lesions.

Conclusions

ELCA effectively vaporized intracoronary thrombus in patients with STEMI even after MT. Lesions with plaque rupture contained larger thrombus burden that was frequently characterized by red thrombus and more effectively reduced by ELCA.

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).

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.

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.

Human monocyte-derived macrophages: Pathogenetic role in plaque rupture associated to systemic inflammation

BACKGROUND

Macrophages play a key role in coronary plaque destabilization. In-vitro human monocyte-derived macrophages (MDMs) are used to study macrophages infiltrating tissue. Optical coherence tomography (OCT) provides an in-vivo insight of the coronary arteries. We compared the MDMs morpho-phenotype and culprit plaque features at OCT in acute coronary syndrome (ACS) patients according to the underlying plaque pathobiology.

METHODS

Sixty-six patients undergoing coronary angiography and pre-angioplasty OCT of the culprit vessel were allocated to three groups according to mechanism of ACS at OCT and C-reactive protein levels (cut-off: 2 mg/Ll): 1) plaque rupture with systemic inflammation; 2) plaque rupture without systemic inflammation, 3) plaque with intact fibrous cap. A blood sample was collected to obtain MDMs, categorized as having "round" or "spindle" morphology.

RESULTS

Thirty-two patients (48.5%) were assigned to Group 1, 10 (15.2%) to Group 2 and 24 (36.4%) to Group 3. The "round" MDMs were significantly more frequent in Group 1 (39.25 ± 4.98%) than in Group 2 (23.89 ± 3.10%) and Group 3 (23.02 ± 7.89%), p = 0.008. MDMs in Group 1 as compared to Groups 2 and 3 showed lower efferocytosis (8.74 ± 1.38 vs 9.74 ± 2.15 vs 11.41 ± 2.41; p = 0.012), higher tissue factor levels (369.84 ± 101.13 vs 301.89 ± 59.78 vs 231.74 ± 111.47; p = 0.001) and higher heme oxygenase-1 expression (678.78 ± 145.43 vs 419.12 ± 74.44 vs 409.78 ± 64.33; p = 0.008).

CONCLUSIONS

MDMs of ACS patients show morpho-phenotypic heterogeneity with prevalence of pro-thrombotic and pro-oxidative properties in case of plaque rupture and systemic inflammation. Such MDMs subpopulation may take part to the cellular pathways leading to fibrous cap rupture with the subsequent thrombus formation.

Influence of Plaque Characteristics on Early Vascular Healing in Patients With ST-Elevation Myocardial Infarction

OBJECTIVES

To compare the early vascular healing of ruptured plaques (RP) and non-ruptured plaques (NRP) one month after primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI), using optical coherence tomography (OCT).

BACKGROUND

Vascular healing and strut coverage are important factors in reducing the risk of stent thrombosis after PCI. Influence of underlying lesion characteristics and differences in healing response between RP and NRP are unknown.

METHODS

Twenty-six STEMI-patients underwent PCI and implantation of a polymer-free drug-coated Biofreedom stent (BF-BES). OCT was performed pre-PCI, post-PCI and at 1-month follow-up. The patients were divided into two groups: RP = 15 and NRP = 11. OCT analyses of culprit lesion, post stent implantation at baseline and follow-up were performed to determine the difference in vascular healing based on presence of uncovered and/or malapposed stent struts and intraluminal filling defects.

RESULTS

The stent coverage did not differ significantly between the two groups at 1-month follow-up with percentage of uncovered struts: RP 26.5% [IQR 15.0-49.0] and NRP 28.1% [IQR 15.5-38.8] for NRP (p = 0.78). At 1-month, RP showed an increased percentage of late acquired malapposed struts (1.4% [IQR 0.8-2.4] vs. 0.0% [IQR 0.0-1.4], p = 0.03) and a larger total malapposition area (1.3 mm² [IQR 0.4-2.5] vs. 0.0 mm² [IQR 0.0-0.9], p = 0.01), compared to NRP.

CONCLUSION

Three out of four struts were covered within one month after stenting. The vascular healing was comparable in RP and NRP on stent coverage. However, RP had more and larger late acquired malapposition areas.

Inflammatory Cytokines and Atherosclerotic Plaque Progression. Therapeutic Implications

PURPOSE OF THE REVIEW

Inflammatory cytokines play a major role in atherosclerotic plaque progression. This review summarizes the rationale for personalized anti-inflammatory therapy.

RECENT FINDINGS

Systemic inflammatory parameters may be used to follow the clinical outcome in primary and secondary prevention. Medical therapy, both in patients with stable cardiovascular disease, or with acute events, may be tailored taking into consideration the level and course of systemic inflammatory mediators. There is significant space for improvement in primary prevention and in the treatment of patients who have suffered from severe cardiovascular events, paying attention to not only blood pressure and cholesterol levels but also including inflammatory parameters in our clinical analysis. The potential exists to alter the course of atherosclerosis with anti-inflammatory drugs. With increased understanding of the specific mechanisms that regulate the relationship between inflammation and atherosclerosis, new, more effective and specific anti-inflammatory treatment may become available.

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.

How can optical coherence tomography be used to optimize percutaneous coronary intervention?

Optical coherence tomography (OCT) imaging provides high resolution assessment of coronary parietal and endoluminal abnormalities. Clinical evidence and intuitive utilization make this tool relevant for use in daily practice in the catheterization laboratory. In the present review, we summarize the benefits of OCT for the optimization of percutaneous coronary intervention (PCI) in daily practice. First, we focus on the characterization of lesion type with a view to anticipating challenges during PCI. Then, we describe the utility of OCT to identify culprit lesions and ambiguous angiographic findings. Finally, we outline targets for optimization after PCI and the mechanisms underlying stent failure.

Culprit lesion morphology in patients with ST-segment elevation myocardial infarction assessed by optical coherence tomography

AIMS

This study sought to evaluate the incidence of ruptured plaques and nonruptured plaques (NRP) and to compare patient characteristics and detailed plaque morphology features between the two culprit types in ST-segment elevation myocardial infarction (STEMI) patients, using optical coherence tomography (OCT).

METHODS AND RESULTS

Using OCT, the culprit lesions in patients with STEMI were assessed prior to stent implantation. The culprit lesion was categorized as ruptured plaques or NRP, and the plaque components were evaluated. Fifty-two patients (69.3%) presented with ruptured plaques and 23 (30.7%) with NRP. Patients with NRP were younger (58.0 ± 10.4 vs 64.7 ± 9.9 years, P = 0.01) and more often smokers (72.7% vs 37.1%, P = 0.001), compared to ruptured plaques. NRP contained significantly more fibrotic plaque (20.0% [interquartile range (IQR) 13.7-29.8] vs 11.3% [IQR 6.9-18.1], P = 0.005), but less lipidic plaque (44.0% ± 13.7 vs 59.3% ± 13.6, P < 0.001), less superficial [5.0% (IQR 2.8-7.5) vs 8.1% (IQR 5.7-11.0), P = 0.005] and profound macrophages [0.9% (IQR 0.0-1.7) vs 2.2% (IQR 0.9-4.7), P = 0.003]. The prevalence, numbers and lengths of thin-cap fibroatheroma (TCFA) were significantly lower in NRP, compared to ruptured plaques [47.8% vs 88.5%, 0 (IQR 0-1) vs 1 (IQR 1-2) and 0 mm (IQR 0-2.7) vs 4.5 mm (IQR 2.3-7.7), P < 0.001].

CONCLUSIONS

One-third of STEMI patients had culprit lesions without an OCT-detectable ruptured plaque. Culprit lesions with NRP contained less vulnerable plaque components, such as lipid plaque, TCFAs and macrophages compared to ruptured plaques.

Clinical Significance of the Presence or Absence of Lipid-Rich Plaque Underneath Intact Fibrous Cap Plaque in Acute Coronary Syndrome

Background Although most coronary thromboses occur on the surface of lipid-rich plaque ( LRP ) with plaque rupture ( PR ), previous pathological and optical coherence tomography studies demonstrated diversity in the morphological characteristics of culprit plaque underlying the thrombus, including lesions with intact fibrous cap ( IFC ). We investigated the clinical significance of IFC in relation to the presence or absence of LRP observed via optical coherence tomography in culprit lesions of acute coronary syndrome. Methods and Results We investigated 510 patients with acute coronary syndrome who underwent optical coherence tomography for the culprit lesion. Optical coherence tomography analysis included the presence or absence of PR , which were categorized into the PR group and the IFC group, respectively. The IFC group was further categorized on the basis of the presence of LRP . Incidence of major adverse cardiac events ( MACEs ), including cardiac death, myocardial infarction, and clinically driven remote revascularizations, was compared. Culprit lesions were categorized into 328 PR s and 182 IFC s. MACEs occurred in 85 patients (16.7%) during the median follow-up duration of 621 days. LRP was detected in 325 lesions (99%) with PR , whereas 60 (33.0%) of the lesions with IFC did not show LRP . Kaplan-Meier analysis revealed significantly lower MACEs in the IFC group compared with the PR group. Furthermore, the IFC group without LRP showed significantly lower MACEs compared with the IFC group with LRP . Multivariate Cox proportional hazards analysis demonstrated that IFC without LRP was an independent predictor of better prognosis. Conclusions Exclusion of LRP underneath IFC culprit lesions in acute coronary syndrome may predict a lower risk of future MACEs .

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.

Ethnic Differences in the Pathobiology of Acute Coronary Syndromes Between Asians and Whites

Ethnic differences in the pathobiology of acute coronary syndromes (ACS) have not been systematically studied. We compared the underlying mechanisms of ACS between Asians and Whites. ACS patients with the culprit lesion imaged by optical coherence tomography were included. Patients were stratified into ST-elevation myocardial infarction (STEMI) and non-ST-elevation-ACS (NSTE-ACS), and baseline characteristics, underlying mechanisms of ACS, and culprit plaque characteristics were compared between Asians and Whites. Of 1,225 patients, 1,019 were Asian (567 STEMI and 452 NSTE-ACS) and 206 were White (71 STEMI and 135 NSTE-ACS). Asians had more diabetes and hypertension among STEMI patients; among NSTE-ACS patients, Asians had higher prevalence of diabetes and renal insufficiency, and lower prevalence of hyperlipidemia. There were no differences in the incidence of plaque rupture, plaque erosion and calcified plaque between Asians and Whites with STEMI (61.2%, 28.6%, 10.2% vs 46.5%, 38.0%, 15.5%, respectively, p = 0.055). Among NSTE-ACS patients, there was a significant difference between Asians and Whites (40.5%, 47.6%, 11.9% vs 27.4%, 48.9%, 23.7%, respectively, p = 0.001). After adjustment for clinical confounders, the risk of plaque rupture (p = 0.713), plaque erosion (p = 0.636), and calcified plaque (p = 0.986) was similar between the groups with STEMI. In NSTE-ACS patients, the only difference was an increased risk of calcified plaque in Whites (odds ratio: 2.125, 95% confidence interval: 1.213 to 3.723, p = 0.008). In conclusion, after adjustment for clinical confounders, Asian and White patients presenting with STEMI and NSTE-ACS showed similar underlying mechanisms of ACS, except for a higher risk of calcified plaque in Whites with NSTE-ACS.

Effect of 1,5-anhydroglucitol levels on culprit plaque rupture in diabetic patients with acute coronary syndrome

BACKGROUND

Postprandial hyperglycemia was reported to play a key role in established risk factors of coronary artery diseases (CAD) and cardiovascular events. Serum 1,5-anhydroglucitol (1,5-AG) levels are known to be a clinical marker of short-term postprandial glucose (PPG) excursions. Low serum 1,5-AG levels have been associated with occurrence of CAD. However, the relationship between 1,5-AG levels and coronary plaque rupture has not been fully elucidated. The aim of this study was to evaluate 1,5-AG as a predictor of coronary plaque rupture in diabetic patients with acute coronary syndrome (ACS).

METHODS

A total of 144 diabetic patients with ACS were included in this study. All patients underwent intravascular ultrasound examination, which revealed 49 patients with plaque rupture and 95 patients without plaque rupture in the culprit lesion. Fasting blood glucose (FBG), hemoglobin A_1c (HbA_1c) and 1,5-AG levels were measured before coronary angiography. Fasting urinary 8-iso-prostaglandin F_2α (8-iso-PGF_2α) level was measured and corrected by creatinine clearance.

RESULTS

Patients with ruptured plaque had significantly lower serum 1,5-AG levels, longer duration of diabetes, higher HbA_1c and FBG levels than patients without ruptured plaque in our study population. In multivariate analysis, low 1,5-AG levels were an independent predictor of plaque rupture (odds ratio 3.421; P = 0.005) in diabetic patients with ACS. The area under the receiver-operating characteristic curve for 1,5-AG (0.658, P = 0.002) to predict plaque rupture was superior to that for HbA_1c (0.587, P = 0.087). Levels of 1,5-AG were significantly correlated with urinary 8-iso-prostaglandin F_2α levels (r = - 0.234, P = 0.005).

CONCLUSIONS

Serum 1,5-AG may identify high risk for coronary plaque rupture in diabetic patients with ACS, which suggests PPG excursions are related to the pathogenesis of plaque rupture in diabetes.

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.

Mean Platelet Volume Predicts Short-term Prognosis in Young Patients with St-segment Elevation Myocardial Infarction

Background: Acute ST-elevation myocardial infarction (STEMI) is an uncommon diagnosis in patients less than 40 years of age. Over the last two decades, there is an increase in the frequency of cardiovascular events among young adults. However, at present there is only limited clinical data on the clinical characteristics and outcomes of STEMI in young patients who were treated with primary percutaneous coronary intervention (pPCI). Plaque erosion is the underlying pathological mechanism leading to STEMI in the vast majority of young adults. Thrombi that complicate superficial erosion seem more platelet-rich than the fibrinous clots precipitated by plaque rupture. Mean platelet volume (MPV) is recognized as a marker of the platelet activation process and may be a better indicator of short-term prognosis than the inflammatory markers in young patients with STEMI. Therefore, we aimed to investigate clinical and angiographic characteristics, risk factors and the independent value of MPV on predicting short-term major adverse cardiovascular events (MACEs) in young adults with STEMI. Methods: A total of 349 patients aged 40 years or younger who underwent pPCI at our center between 2010–2015 with the diagnosis of STEMI were retrospectively analyzed. Results: The mean age of the patients was 36.4 ± 3.6 years and 90% of them were men. Smoking was by far the most frequent cardiovascular risk factor. MACEs were observed in 23 patients (6.6%), and according to the multivariate regression analysis, Killip IIIIV (OR 7.52, 95% CI 1.25–45.24, p = 0.03), lower admission SBP (OR 0.94, 95% CI 0.90–0.98, p <0.01) and increased MPV (OR 1.67, 95% CI 1.05–2.67, p = 0.03) were found to be independently correlated with MACE in the study population. Conclusion: Our results indicate that MPV is an independent predictor of MACEs at the short-term follow-up in young patients with STEMI undergoing pPCI. Accordingly, we suggested that MPV, a marker of platelet activation, could play a significant role in predicting clinical evolution in young patients with STEMI.