Intravascular Ultrasound Assessment of Ulcerated Ruptured Plaques

CVIT 2023 clinical expert consensus document on intravascular ultrasound

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.

Safety and feasibility of intravascular ultrasound-guided robotic percutaneous coronary intervention

OBJECTIVE

Previous studies have demonstrated the benefit of intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) for preventing longitudinal geographic miss (LGM). However, it is yet unclear whether IVUS guidance is useful for robotic-PCI (robotic-assisted perctaneous coronary intervention [R-PCI]).

METHODS

A total of 58 consecutive patients with stable angina who underwent IVUS-guided R-PCI were enrolled. The stent landing position was angiographically marked using a balloon marker before stenting, followed by measurements of the expected stent length using balloon pullback. Subsequently, prestenting IVUS was performed to determine stent landing. All pre-PCI IVUS images were assessed for lesion length and percent plaque volume (%PV) using both IVUS and angiographic marking. LGM was defined as a residual %PV >50% at either the distal or proximal stent edge, any stent edge dissection, or additional stent deployment immediately after stenting.

RESULTS

The included patients had an average age of 67.1 ± 10.1 years. IVUS guidance had significantly longer lesion lengths compared with angiographic marking. Based on IVUS-guided stent deployment, nine cases exhibited LGM immediately after stenting. IVUS-marked landing points had a significantly smaller %PV and significantly larger lumen area compared with those for angiography.

CONCLUSION

IVUS-guided R-PCI was well-tolerated and may be better at preventing LGM compared with angiography-guided R-PCI.

Label-free atherosclerosis diagnosis through a blood drop of apolipoprotein E knockout mouse model using surface-enhanced Raman spectroscopy validated by machine learning algorithm

The direct preventative detection of flow-induced atherosclerosis remains a significant challenge, impeding the development of early treatments and prevention measures. This study proposes a method for diagnosing atherosclerosis in the carotid artery using nanometer biomarker measurements through surface-enhanced Raman spectroscopy (SERS) from single-drop blood samples. Atherosclerotic acceleration is induced in apolipoprotein E knockout mice which underwent a partial carotid ligation and were fed a high-fat diet to rapidly induce disturbed flow-induced atherosclerosis in the left common carotid artery while using the unligated, contralateral right carotid artery as control. The progressive atherosclerosis development of the left carotid artery was verified by micro-magnetic resonance imaging (micro-MRI) and histology in comparison to the right carotid artery. Single-drop blood samples are deposited on chips of gold-coated ZnO nanorods grown on silicon wafers that filter the nanometer markers and provide strong SERS signals. A diagnostic classifier was established based on principal component analysis (PCA), which separates the resultant spectra into the atherosclerotic and control groups. Scoring based on the principal components enabled the classification of samples into control, mild, and severe atherosclerotic disease. The PCA-based analysis was validated against an independent test sample and compared against the PCA-PLS-DA machine learning algorithm which is known for applicability to Raman diagnosis. The accuracy of the PCA modification-based diagnostic criteria was 94.5%, and that of the machine learning algorithm 97.5%. Using a mouse model, this study demonstrates that diagnosing and classifying the severity of atherosclerosis is possible using a single blood drop, SERS technology, and machine learning algorithm, indicating the detectability of biomarkers and vascular factors in the blood which correlate with the early stages of atherosclerosis development.

Intravascular ultrasound insights into the unstable features of the coronary atherosclerotic plaques: A systematic review and meta-analysis

BACKGROUND

There is a lack of a comprehensive picture of plaque geometry and composition of unstable atherosclerotic lesions as observed with intravascular ultrasound techniques. We analysed through a systematic review with meta-analysis 39 characteristics of atherosclerotic plaques in three scenarios involving culprit and non-culprit lesions from acute coronary syndromes vs stable angina pectoris patients, and culprit vs non-culprit lesions in acute coronary syndromes patients.

METHODS

A systematic search of PubMed and EMBASE, from inception to April 2020 was performed. The combined odds ratios or mean differences of all IVUS characteristics were calculated with random-effects models.

RESULTS

Twenty-eight studies involving 5434 subjects, and 5618 lesions were included. Culprit lesions in acute coronary syndromes have larger plaque areas and remodeling indexes (MD = 0.13 [0.08; 0.17], p < 0.001) and contained larger necrotic cores (MD = 0.67 (95% CI 0.19;1.15), p = 0.006) that stable angina culprit lesions. In acute patients, culprit plaques were also more remodeled, had larger necrotic cores and had more frequently a Thin-Cap Fibroatheroma morphology (OR = 1.79 (95% CI 1.21; 2.65), p = 0.004) than non-culprit lesions. Non-culprit lesions in acute syndromes were more often ruptured (OR = 2.25 (95% CI:1.05; 4.82), p = 0.037) or Thin-Cap Fibroatheromas than in stable angina.

CONCLUSION

Culprit lesions from acute coronary patients are larger, more positively remodeled and contained more lipids as compared to stable angina lesions or non-culprit in acute patients. Non culprit lesions are also more often complicated or vulnerable in acute than stable patients.

Myocardial infarction with non-obstructive coronary artery disease

As a result of the increased use of coronary angiography in acute myocardial infarction in the last two decades, myocardial infarction with non-obstructive coronary arteries (MINOCA) has received growing attention in everyday clinical practice. At the same time, research interest in MINOCA has increased significantly. MINOCA is a heterogeneous disease entity seen in 5-10% of all patients with myocardial infarction, especially in women. Clinically, MINOCA may be difficult to distinguish from other non-ischaemic conditions that can cause similar symptoms and myocardial injury. There is still some confusion around the diagnosis, investigation and management of patients with MINOCA. The present review summarises the current knowledge of MINOCA regarding epidemiology, pathophysiology, investigation, and treatment, with a special focus on imaging modalities. In addition, remaining important knowledge gaps are highlighted.

Clinical expert consensus document on intravascular ultrasound from the Japanese Association of Cardiovascular Intervention and Therapeutics (2021)

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this updated expert consensus document summarizes the methods of measurements and assessment of IVUS images and the clinical evidence of IVUS use in percutaneous coronary intervention.

Mechanically Rotating Intravascular Ultrasound (IVUS) Transducer: A Review

Intravascular ultrasound (IVUS) is a valuable imaging modality for the diagnosis of atherosclerosis. It provides useful clinical information, such as lumen size, vessel wall thickness, and plaque composition, by providing a cross-sectional vascular image. For several decades, IVUS has made remarkable progress in improving the accuracy of diagnosing cardiovascular disease that remains the leading cause of death globally. As the quality of IVUS images mainly depends on the performance of the IVUS transducer, various IVUS transducers have been developed. Therefore, in this review, recently developed mechanically rotating IVUS transducers, especially ones exploiting piezoelectric ceramics or single crystals, are discussed. In addition, this review addresses the history and technical challenges in the development of IVUS transducers and the prospects of next-generation IVUS transducers.

Three-Dimensional Fluid Dynamical Features of Coronary Plaque Rupture Provoking Acute Coronary Syndrome

AIM

Coronary plaque rupture is the main cause of acute coronary syndrome (ACS), but the role of blood flow features around plaque rupture for ACS is still unknown. The present study aimed to assess the relationship between the geometric configuration of ruptured plaque and ACS occurrence using computational fluid dynamics (CFD) by moving particle method in patients with coronary artery disease.

METHODS

In this study, 45 patients with coronary artery disease who underwent three-dimensional intravascular ultrasound (IVUS) and had a coronary ruptured plaque (24 plaques with provoked ACS, 21 without) were included. To compare the difference in blood flow profile around ruptured plaque between the patients with and without ACS, the IVUS images were analyzed via the novel CFD analysis.

RESULTS

There were no significant differences in localized flow profile around ruptured plaque between the two groups when the initial particle velocity was 10.0 cm/s corresponded to a higher coronary flow velocity at ventricular diastole. However, when it was 1.0 cm/s corresponded to lower coronary flow velocity at ventricular systole, particles with lower velocity (0 ≤ V ≤ 5 cm/s) were more prevalent around ACS-PR (p=0.035), whereas particles with higher velocity (10 ≤ V ≤ 20 cm/s) were more often detected in silent plaque ruptures (p=0.018).

CONCLUSIONS

Three-dimensional IVUS revealed that coronary plaque rupture was a complex one with a wide variety of its stereoscopic configuration, leading to various patterns of the local coronary flow profile. A novel CFD analysis suggested that the local flow was more stagnant around ACS-provoked ruptures than in silent ones.

High spatial endothelial shear stress gradient independently predicts site of acute coronary plaque rupture and erosion

AIMS

To investigate local haemodynamics in the setting of acute coronary plaque rupture and erosion.

METHODS AND RESULTS

Intracoronary optical coherence tomography performed in 37 patients with acute coronary syndromes caused by plaque rupture (n = 19) or plaque erosion (n = 18) was used for three-dimensional reconstruction and computational fluid dynamics simulation. Endothelial shear stress (ESS), spatial ESS gradient (ESSG), and oscillatory shear index (OSI) were compared between plaque rupture and erosion through mixed-effects logistic regression. Lipid, calcium, macrophages, layered plaque, and cholesterol crystals were also analysed. By multivariable analysis, only high ESSG [odds ratio (OR) 5.29, 95% confidence interval (CI) 2.57-10.89, P < 0.001], lipid (OR 12.98, 95% CI 6.57-25.67, P < 0.001), and layered plaque (OR 3.17, 95% CI 1.82-5.50, P < 0.001) were independently associated with plaque rupture. High ESSG (OR 13.28, 95% CI 6.88-25.64, P < 0.001), ESS (OR 2.70, 95% CI 1.34-5.42, P = 0.005), and OSI (OR 2.18, 95% CI 1.33-3.54, P = 0.002) independently associated with plaque erosion. ESSG was higher at rupture sites than erosion sites [median (interquartile range): 5.78 (2.47-21.15) vs. 2.62 (1.44-6.18) Pa/mm, P = 0.009], OSI was higher at erosion sites than rupture sites [1.04 × 10-2 (2.3 × 10-3-4.74 × 10-2) vs. 1.29 × 10-3 (9.39 × 10-5-3.0 × 10-2), P < 0.001], but ESS was similar (P = 0.29).

CONCLUSIONS

High ESSG is independently associated with plaque rupture while high ESSG, ESS, and OSI associate with plaque erosion. While ESSG is higher at rupture sites than erosion sites, OSI is higher at erosion sites and ESS was similar. These results suggest that ESSG and OSI may play critical roles in acute plaque rupture and erosion, respectively.

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 .

Intracoronary Imaging for Assessment of Vascular Healing and Stent Follow-up in Bioresorbable Vascular Scaffolds

Bioresorbable Vascular Scaffolds (BVS) are polymer-based materials implanted in the coronary arteries in order to treat atherosclerotic lesions, based on the concept that once the lesion has been treated, the material of the implanted stent will undergo a process of gradual resorption that will leave, in several years, the vessel wall smooth, free of any foreign material and with its vasomotion restored. However, after the first enthusiastic reports on the efficacy of BVSs, the recently published trials demonstrated disappointing results regarding long-term patency following BVS implantation, which were mainly attributed to technical deficiencies during the stenting procedure. Intracoronary imaging could play a crucial role for helping the operator to correctly implant a BVS into the coronary artery, as well as providing relevant information in the follow-up period. This review aims to summarize the role of intracoronary imaging in the follow-up of coronary stents, with a particular emphasis on the role of intravascular ultrasound and optical coherence tomography for procedural guidance during stent implantation and also for follow-up of bioabsorbable scaffolds.

Clinical expert consensus document on standards for measurements and assessment of intravascular ultrasound from the Japanese Association of Cardiovascular Intervention and Therapeutics

Intravascular ultrasound (IVUS) provides precise anatomic information in coronary arteries including quantitative measurements and morphological assessment. To standardize the IVUS analysis in the current era, this expert consensus document summarizes the methods of measurements and assessment of IVUS images.

Association of Isoprostanes-Related Oxidative Stress with Vulnerability of Culprit Lesions in Diabetic Patients with Acute Coronary Syndrome

Urinary excretion of 8-iso-prostaglandin F_2α (8-iso-PGF_2α), a reliable biomarker for enhanced oxidant stress in vivo, has been described in association with diabetes and coronary heart disease. The aim of this study was to evaluate the relationship between urinary 8-iso-PGF_2α levels and the characteristics of coronary culprit lesion in diabetic patients with acute coronary syndrome (ACS). A total of 79 diabetic patients with ACS were included. iMAP intravascular ultrasound (iMAP-IVUS) was performed to evaluate the characteristics of culprit plaques. Fasting urinary 8-iso-PGF_2α level was measured and corrected by creatinine clearance. iMAP-IVUS data showed culprit plaques in high urinary 8-iso-PGF_2α level patients had a greater percentage of necrotic core and less fibrous components. High urinary 8-iso-PGF_2α levels were correlated with increased necrotic plaque components (r = 0.325, P = 0.003). Meanwhile, the presence of thin-capped fibroatheroma (50.0% versus 11.5%, P = 0.003), ruptured plaques (30.8% versus 7.7%, P = 0.035), and thrombus (38.5% versus 7.7%, P = 0.008) were significantly more frequent in the upper tertile of urinary 8-iso-PGF_2α levels than in the low tertile. Multivariate analysis showed high levels of urinary 8-iso-PGF_2α (OR 4.240, P = 0.007) was independently associated with the presence of vulnerable culprit plaque in diabetic ACS patients. Urinary 8-iso-PGF_2α also displayed a significant value in predicting vulnerable plaques in diabetic patients with ACS by constructing the receiver-operating characteristic (ROC) curve (Area under the ROC curve: 0.713, P = 0.001). Urinary 8-iso-PGF_2α levels are associated with the vulnerability of the coronary culprit lesion in diabetic patients with ACS and may provide additional information for risk assessment in suspected vulnerable patients.

Coronary Atherosclerotic Plaque Vulnerability Rather than Stenosis Predisposes to Non-ST Elevation Acute Coronary Syndromes

Background

Non-ST elevation acute coronary syndromes (NSTE-ACS) may arise from moderately stenosed atherosclerotic lesions that suddenly undergo transformation to vulnerable plaques complicated by rupture and thrombosis.

Objective

Assessment and tissue characterization of the coronary atherosclerotic lesions among NSTE-ACS patients compared to those with stable angina.

Methodology

Evaluation of IVUS studies of 312 coronary lesions was done by 2 different experienced IVUS readers, 216 lesions in 66 patients with NSTE-ACS (group I) versus 96 lesions in 50 patients with stable angina (group II). Characterization of coronary plaques structure was done using colored-coded iMap technique.

Results

The Syntax score was significantly higher in group I compared to group II (18.7 ± 7.8 vs. 8.07 ± 2.5, p=0.001). Body mass index (BMI) was significantly higher in group II while triglycerides levels were higher in group I (P=0.01 & P=0.04, respectively). History of previous MI and PCI was significantly higher in group I (P=0.016 & P=0.001, respectively). The coronary lesions of NSTE-ACS patients had less vessel area (9.86 ± 3.8 vs 11.36 ± 2.9, p=0.001), stenosis percentage (54.7 ± 14.9% vs 68.6 ± 8.7%, p=0.001), and plaque burden (54.4 ± 14.7 vs 67.8 ± 9.8, p=0.001) with negative remodeling index (0.95 ± 20 vs 1.02 ± 0.14, p=0.008) compared to the stable angina group. On the other hand, they had more lipid content (21.8 ± 7.03% vs 7.26 ± 3.47%, p=0.001), necrotic core (18.08 ± 10.19% vs 15.83 ± 4.9%, p=0.02), and calcifications (10.4 ± 5.2% vs 4.19 ± 3.29%, p=0.001) while less fibrosis (51.67 ± 7.07% vs 70.37 ± 11.7%, p=0.001) compared to the stable angina patients. Syntax score and core composition especially calcification and lipid content were significant predictors to NSTE-ACS.

Conclusions

The vulnerability rather than the stenotic severity is the most important factor that predisposes to non-ST segment elevation acute coronary syndromes. The vulnerability is related to the lesion characteristics especially lipidic core and calcification while lesion fibrosis favours lesion stability.

Carotid Plaque Vulnerability Assessment Using Ultrasound Elastography and Echogenicity Analysis

OBJECTIVE

The purpose of this study was to evaluate ultrasound elastography and echogenicity analysis to discriminate between carotid plaques in patients with symptomatic internal carotid artery (ICA) stenosis versus patients with asymptomatic stenosis.

SUBJECTS AND METHODS

Patients with symptomatic and asymptomatic ICA stenosis of more than 50% were recruited for the study. After both carotid arteries were scanned, plaque translation and elastography and echogenicity features were assessed. Parameters of index stenosis (i.e., symptomatic or more severe stenosis) were compared between populations. For further validation, parameters of index stenosis were also compared with those of the contralateral artery for segments with plaque. Segments without plaque on the index side were also evaluated between populations. ROC curve analyses were performed using a cross-validation method with bootstrapping to calculate sensitivity and specificity.

RESULTS

Sixty-six patients with symptomatic (n = 26) or asymptomatic (n = 40) carotid stenoses were included. The maximum axial strain (p < 0.001), maximum axial shear strain magnitude (p = 0.03), and percentage of low-intensity of gray level (p = 0.01) of the index ICA were lower for patients with symptoms than for those without symptoms. In both groups, the contralateral ICA had translation and elastography and echogenicity parameters similar to those of the index ICA in patients with asymptomatic stenosis. The ROC curve for the detection of vulnerable plaques in patients with symptomatic stenosis was higher when ultrasound elastography and ultrasound echogenicity were used in combination than when each method was used alone (p < 0.001); a sensitivity of 71.6% and a specificity of 79.3% were obtained.

CONCLUSION

This pilot study establishes the usefulness of combining elastography with echogenicity analysis to discriminate plaques in patients with symptomatic ICA stenosis versus asymptomatic stenosis.

Biomechanical stress in coronary atherosclerosis: emerging insights from computational modelling

Coronary plaque rupture is the most common cause of vessel thrombosis and acute coronary syndrome. The accurate early detection of plaques prone to rupture may allow prospective, preventative treatment; however, current diagnostic methods remain inadequate to detect these lesions. Established imaging features indicating vulnerability do not confer adequate specificity for symptomatic rupture. Similarly, even though experimental and computational studies have underscored the importance of endothelial shear stress in progressive atherosclerosis, the ability of shear stress to predict plaque progression remains incremental. This review examines recent advances in image-based computational modelling that have elucidated possible mechanisms of plaque progression and rupture, and potentially novel features of plaques most prone to symptomatic rupture. With further study and clinical validation, these markers and techniques may improve the specificity of future culprit plaque detection.

Atherosclerotic Coronary Plaque Development Visualized by In Vivo Coronary Imaging

In the past decades, coronary imaging has evolved as a valuable adjunct to angiography, providing scientific insights into vascular biology and practical guidance by direct visualization of atherosclerosis and other pathologic conditions within the vessel walls. Especially with intravascular ultrasound (IVUS), the signal is able to penetrate below the luminal surface, so the entire cross-section of an artery, including the complete thickness of the plaque, can be imaged in real-time. On the other hand, optical coherence tomography (OCT) has been offering higher image resolution of both the plaque and the luminal surface. These technologies offer the opportunity to gather diagnostic information about the process of atherosclerosis and to directly observe the effects of various interventions on the plaque and arterial walls. IVUS has proven itself to be a practical and useful tool in the evaluation and optimal guidance of interventional vascular medicine. In this review, we detail the current modalities of coronary imaging and their usefulness in the diagnosis and management of patients with high-risk coronary plaques.

Frequency-domain optical coherence tomography plaque morphology in stable coronary artery disease: sex differences

BACKGROUND

The cause for discrepancy in the clinical presentation and outcome of coronary artery disease (CAD) between men and women is not established. Different prevalences of risk factors or specific sex-related atherosclerotic aspects have been advocated as possible explanations. We investigated coronary plaque morphology looking at possible differences in plaque vulnerability between men and women with stable CAD.

PATIENTS AND METHODS

We retrospectively collected and analyzed clinical data and coronary plaque morphology by frequency-domain optical coherence tomography in men and women with stable CAD.

RESULTS

A total of 181 (139 were in men and 42 in women) plaques from 138 patients were analyzed. The mean age was similar between men and women. Besides an overall absence of significant differences in the vast majority of risk factors and comorbidities, men had a higher prevalence of active smoking (19 vs. 2%, P=0.006), previous myocardial infarction (17 vs. 2%, P=0.01), and previous percutaneous coronary interventions (42 vs. 17%, P=0.003). Frequency-domain optical coherence tomography in women showed significantly more plaque-vulnerability features as testified by higher percent of lipid-rich plaques (55 vs. 36%, P=0.03), macrophages (21 vs. 5%, P=0.003), and microvessels (24 vs. 8%, P=0.01). Multivariate analysis showed that female sex was associated independently with lipid-rich plaques (P=0.034) and macrophages (P=0.001). In the analysis restricted to the more severe lesions that were revascularized, women continued to be characterized by more adverse morphological features, such as macrophages (30 vs. 7%, P=0.004) and lipid-rich plaques (63 vs. 39%, P=0.045).

CONCLUSION

Women with stable CAD may be characterized by plaques that have increased prevalence of vulnerability compared with men. These findings support the hypothesis of sex-specific differences in the development of atherosclerosis.

Temporal and spatial changes in wall shear stress during atherosclerotic plaque progression in mice

Wall shear stress (WSS) is involved in atherosclerotic plaque initiation, yet its role in plaque progression remains unclear. We aimed to study (i) the temporal and spatial changes in WSS over a growing plaque and (ii) the correlation between WSS and plaque composition, using animal-specific data in an atherosclerotic mouse model. Tapered casts were placed around the right common carotid arteries (RCCA) of ApoE^-/- mice. At 5, 7 and 9 weeks after cast placement, RCCA geometry was reconstructed using contrast-enhanced micro-CT. Lumen narrowing was observed in all mice, indicating the progression of a lumen intruding plaque. Next, we determined the flow rate in the RCCA of each mouse using Doppler Ultrasound and computed WSS at all time points. Over time, as the plaque developed and further intruded into the lumen, absolute WSS significantly decreased. Finally at week 9, plaque composition was histologically characterized. The proximal part of the plaque was small and eccentric, exposed to relatively lower WSS. Close to the cast a larger and concentric plaque was present, exposed to relatively higher WSS. Lower WSS was significantly correlated to the accumulation of macrophages in the eccentric plaque. When pooling data of all animals, correlation between WSS and plaque composition was weak and no longer statistically significant. In conclusion, our data showed that in our mouse model absolute WSS strikingly decreased during disease progression, which was significantly correlated to plaque area and macrophage content. Besides, our study demonstrates the necessity to analyse individual animals and plaques when studying correlations between WSS and plaque composition.

Coronary Plaque Characteristics Associated With Reduced TIMI (Thrombolysis in Myocardial Infarction) Flow Grade in Patients With ST-Segment-Elevation Myocardial Infarction: A Combined Optical Coherence Tomography and Intravascular Ultrasound Study

BACKGROUND

Previous studies reported that reduced TIMI (Thrombolysis in Myocardial Infarction) flow grade before procedure was associated with worse clinical outcomes in patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention. The aim of this study was to identify specific morphological characteristics of the culprit plaque associated with poor TIMI flow grade at baseline in patients with ST-segment-elevation myocardial infarction using both optical coherence tomography and intravascular ultrasound.

METHODS AND RESULTS

A total of 111 ST-segment-elevation myocardial infarction patients who underwent percutaneous coronary intervention within 24 hours of symptom onset were included. Both optical coherence tomography and intravascular ultrasound were performed after thrombectomy. Patients were divided into 2 groups according to preprocedural TIMI flow grade (TIMI 0-1 [n=82] and TIMI 2-3 [n=29]). Patients with preprocedural TIMI 0 to 1 had a greater lipid arc (P=0.037), a longer lipid length (P=0.021), and a greater lipid index (P=0.007) determined by optical coherence tomography and a larger external elastic membrane cross-sectional area (P=0.030) and plaque plus media cross-sectional area (P=0.030) determined by intravascular ultrasound, compared with patients with preprocedural TIMI 2 to 3.

CONCLUSIONS

ST-segment-elevation myocardial infarction patients with reduced TIMI flow grade at baseline have greater lipid burden, larger vessel sizes, and larger plaque areas.

[Contribution of intracoronary imaging in acute coronary syndrome]

Acute coronary syndrome (ACS) remains a major cause of mortality and morbidity in the world, although it has considerably decreased through technical and pharmacological advances. The physiopathological approach of the ACS has progressed considerably in recent years thanks to the anatomopathological work and the data of the endocoronary imaging, in particular of the endovascular ultrasound (IVUS). Plaque rupture is the most common cause of ACS, however OCT (optical coherence tomography) studies have shown that surface plaque erosion was more common than thought. The use of OCT in the ACS may prove to be a valuable diagnostic aid: study of the culpable lesion, spontaneous coronary dissection or intramural spontaneous hematoma, stent thrombosis; from a therapeutic point of view: reduction of the risk of stent malapposition, additional technique, delayed stenting, implantation of a bioresorbable stent, medical treatment of ACS without stenting. Endocoronary imaging, especially OCT, will of course never be systematic as treatment of ACS, but providing excellent value for both diagnosis and treatment, it must be an integral part of the therapeutic arsenal available in cathlab.

Effect of intraplaque angiogenesis to atherosclerotic rupture-prone plaque induced by high shear stress in rabbit model

Atherosclerotic prone-rupture plaque is mainly localized in the region of the entrance to the stenosis with high shear stress and the reasons are largely unknown. Our hypothesis is that such a distribution of cells in atherosclerotic plaque may depend on the angiogenesis. Silastic collars induced regions of high shear stress (20.68 ± 5.27 dynes/cm²) in the upstream flow and low shear stress (12.25 ± 1.28 dynes/cm²) in the downstream flow in carotid arteries. Compared with the low shear stress region, plaques in the high shear stress region showed more intraplaque haemorrhaging, less collagen and higher apoptotic rates of vascular smooth muscle cells; endothelial cells (ECs) in the high shear stress region were characterized with integrity and high endothelial nitric oxide synthase (eNOS) expression (1570.3 ± 345.5% vs 172.9 ± 49.9%). The number of intraplaque microvessels is very high in the high shear stress region (15 ± 1.8 n/mm² vs 3.5 ± 0.4 n/mm²), and the microvessels in the plaque show ECs were abnormal, with membrane blebs, intracytoplasmic vacuoles and leukocyte infiltration. Our current study reveals that the integrity of the endothelium and the vulnerability of atherosclerotic plaques are simultaneously localized in high shear stress regions, and we provide evidence for the first time that microvessels in the intraplaque maybe responsible for rupture-prone plaque formation in the high shear stress region.

Tissue characterization of non-culprit intermediate coronary lesions in non ST elevation acute coronary syndromes

Background

Disruption of vulnerable plaques is the most common cause of acute coronary syndromes. Intravascular ultrasound facilitates cross-sectional imaging of coronary arteries. We aimed at using IVUS to investigate the morphology and tissue characteristics of atherosclerotic plaques of non-culprit intermediate coronary lesions in non-ST elevation ACS setting.

Methods

IVUS assessment of sixty-one intermediate coronary lesions in twenty-eight patients with the diagnosis of Non ST elevation acute coronary syndromes. Ultrasound signals were obtained by an IVUS system using a 40-MHz catheter.

Results

Mean age was 53.2 ± 9.1 years. Males = 20 (71.4%). Smoking in 17 (60.7%), hypertension in 16 (57.1%), Dyslipidemia in 12 (42.9%) and DM in 8 (28.6%). Culprit vessels represent 42% of affected vessels. Sixty-one intermediate lesions were detected. Twenty-nine lesions in culprit vessels and thirty-two lesions in non-culprit vessels with higher lipidic content in lesions of culprit vessels (P < 0.001) while a higher calcific content in lesions of non-culprit vessels (P < 0.001). Higher calcific content of proximal more than distal lesions (P = 0.048). Negative remodeling in 55.7% of lesions.

Conclusions

A higher lipidic content in lesions of culprit vessels, while the lesions of non-culprit vessels were more calcific. Higher calcific content of proximal more than distal lesions was defined as well.

Molecular imaging of the extracellular matrix in the context of atherosclerosis

This review summarizes the current status of molecular imaging of the extracellular matrix (ECM) in the context of atherosclerosis. Apart from cellular components, the ECM of the atherosclerotic plaque plays a relevant role during the initiation of atherosclerosis and its' subsequent progression. Important structural and signaling components of the ECM include elastin, collagen and fibrin. However, the ECM not only plays a structural role in the arterial wall but also interacts with different cell types and has important biological signaling functions. Molecular imaging of the ECM has emerged as a new diagnostic tool to characterize biological aspects of atherosclerotic plaques, which cannot be characterized by current clinically established imaging techniques, such as X-ray angiography. Different types of molecular probes can be detected in vivo by imaging modalities such as magnetic resonance imaging (MRI), positron emission tomography (PET) and single photon emission computed tomography (SPECT). The modality specific signaling component of the molecular probe provides information about its spatial location and local concentration. The successful introduction of molecular imaging into clinical practice and guidelines could open new pathways for an earlier detection of disease processes and a better understanding of the disease state on a biological level. Quantitative in vivo molecular parameters could also contribute to the development and evaluation of novel cardiovascular therapeutic interventions and the assessment of response to treatment.

High shear stress induces atherosclerotic vulnerable plaque formation through angiogenesis

Rupture of atherosclerotic plaques causing thrombosis is the main cause of acute coronary syndrome and ischemic strokes. Inhibition of thrombosis is one of the important tasks developing biomedical materials such as intravascular stents and vascular grafts. Shear stress (SS) influences the formation and development of atherosclerosis. The current review focuses on the vulnerable plaques observed in the high shear stress (HSS) regions, which localizes at the proximal region of the plaque intruding into the lumen. The vascular outward remodelling occurs in the HSS region for vascular compensation and that angiogenesis is a critical factor for HSS which induces atherosclerotic vulnerable plaque formation. These results greatly challenge the established belief that low shear stress is important for expansive remodelling, which provides a new perspective for preventing the transition of stable plaques to high-risk atherosclerotic lesions.

Evaluation of Variable Thin-Cap Fibroatheroma Definitions and Association of Virtual Histology-Intravascular Ultrasound Findings With Cavity Rupture Size

The accepted definition of virtual histology intravascular ultrasound (IVUS-VH) thin-cap fibroatheroma (TCFA) is only a modest predictor of plaque rupture (PR). We sought to determine the relation between IVUS-VH findings and culprit lesions with PR using computational analysis. A total of 80 culprit lesions from 80 patients with stable angina (n = 37), unstable angina (n = 20), and myocardial infarction (n = 23) were divided into those with (n = 15) and without PR (n = 65). By use of automated computational analysis, the standard IVUS-VH TCFA criterion and 124 additional criteria were compared. The standard TCFA definition demonstrated modest ability to discriminate lesions with and without PR (sensitivity 87%, specificity 37%, PPV 0.24, and NPV 0.92). Of 124 additional IVUS-VH TCFA definitions, only 2 improved the discriminative ability even modestly. However, a positive correlation was demonstrated between cavity size and necrotic core percentage (r = 0.78, p <0.01) and a negative correlation with percentage of fibrous tissue (r = -0.81, p <0.01). In conclusion, IVUS-VH criteria were only modestly associated with PR, without significant improvement by varying IVUS-VH TCFA features, but IVUS-VH features of ruptured plaques were strongly correlated with cavity size.

Virtual Histology Intravascular Ultrasound in Carotid Interventions

Purpose:

To report early clinical experience with virtual histology intravascular ultrasound (VH IVUS) in carotid endoluminal repair.

Technique:

A 2.9-F, 20-MHz catheter that utilizes computer software to demonstrate the histological components of arteriosclerotic plaque was evaluated during carotid angioplasty and stenting. VH IVUS images were created following a pullback through the carotid stenosis and produced a color-coded map of the different histological constituents of the disease (dark green: fibrous, yellow/green: fibrofatty, white: calcified, and red: necrotic lipid core plaque).

Conclusion:

VH IVUS produces a color-coded map of the different histological components of artery plaque. It has the potential to predict how the plaque is likely to behave at the moment of endoluminal treatment.

Fusion of fibrous cap thickness and wall shear stress to assess plaque vulnerability in coronary arteries: a pilot study

Purpose

Identification of rupture-prone plaques in coronary arteries is a major clinical challenge. Fibrous cap thickness and wall shear stress are two relevant image-based risk factors, but these two parameters are generally computed and analyzed separately. Accordingly, combining these two parameters can potentially improve the identification of at-risk regions. Therefore, the purpose of this study is to investigate the feasibility of the fusion of wall shear stress and fibrous cap thickness of coronary arteries in patient data.

Methods

Fourteen patients were included in this pilot study. Imaging of the coronary arteries was performed with optical coherence tomography and with angiography. Fibrous cap thickness was automatically quantified from optical coherence tomography pullbacks using a contour segmentation approach based on fast marching. Wall shear stress was computed by applying computational fluid dynamics on the 3D volume reconstructed from two angiograms. The two parameters then were co-registered using anatomical landmarks such as side branches.

Results

The two image modalities were successfully co-registered, with a mean (±SD) error corresponding to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$8.6\,\pm \,6.7\,\%$$\end{document}8.6±6.7% of the length of the analyzed region. For all the analyzed participants, the average thinnest portion of each fibrous cap was \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$129\,\pm \,69\,\upmu \text {m}$$\end{document}129±69μm, and the average WSS value at the location of the fibrous cap was \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1.46\,\pm \,1.16\,\text {Pa}$$\end{document}1.46±1.16Pa. A unique index was finally generated for each patient via the fusion of fibrous cap thickness and wall shear stress measurements, to translate all the measured parameters into a single risk map.

Conclusion

The introduced risk map integrates two complementary parameters and has potential to provide valuable information about plaque vulnerability.

Usefulness of Intravascular Ultrasound for Predicting Risk of Intraprocedural Stent Thrombosis

Intraprocedural stent thrombosis (IPST) is a rare complication of percutaneous coronary intervention that leads to poor outcomes; however, the factors contributing to IPST remain largely unknown. Accordingly, we used intravascular ultrasound (IVUS) to examine the lesion characteristics in patients with IPST. We retrospectively analyzed 1,504 consecutive stent-implanted lesions in 1,324 patients (326 with ST-segment elevation myocardial infarction [STEMI], 403 patients with non-ST-segment elevation acute coronary syndrome [NSTE-ACS], and 595 patients with stable angina). Of these, IPST occurred in 5 patients during percutaneous coronary intervention (0.4% per patient; 3 with STEMI, 2 with NSTE-ACS). The IVUS characteristics of plaques that developed IPST were compared with those of controls without the evidence of IPST (non-IPST; n = 15) who were matched by age, gender, lesion location, and clinical presentation (STEMI, NSTE-ACS, or stable angina). All 5 lesions that led to IPST had ruptured plaques with positive remodeling and attenuation. Plaque rupture was also observed in 40% of the non-IPST group. Multiple plaque ruptures in the culprit lesion were more common in the IPST group (80% vs 7%; p <0.01). The maximum cavity area was larger in the IPST group than in the non-IPST group having plaque rupture (4.6 mm(2) [interquartile range, 4.3 to 6.5] vs 2.4 mm(2) [1.8 to 2.9]; p <0.01). In conclusion, we found using IVUS that multiple plaque ruptures with larger cavities more often evolved into IPST.

Plaque disruption by coronary computed tomographic angiography in stable patients vs. acute coronary syndrome: a feasibility study

AIMS

This study was designed to determine whether coronary CT angiography (CTA) can detect features of plaque disruption in clinically stable patients and to compare lesion prevalence and features between stable patients and those with acute coronary syndrome (ACS).

METHODS

We retrospectively identified patients undergoing CTA, followed by invasive coronary angiography (ICA) within 60 days. Quantitative 3-vessel CTA lesion analysis was performed on all plaques ≥25% stenosis to assess total plaque volume, low attenuation plaque (LAP, <50 HU) volume, and remodelling index. Plaques were qualitatively assessed for CTA features of disruption, including ulceration and intra-plaque dye penetration (IDP). ICA was employed as a reference standard for disruption. A total of 145 (94 ACS and 51 stable) patients were identified. By CTA, plaque disruption was evident in 77.7% of ACS cases. Although more common among those with ACS, CTA also detected plaque disruption in 37.3% of clinically stable patients (P < 0.0001).

CONCLUSIONS

Clinically stable patients commonly manifest plaques with features of disruption as determined by CTA. Though the prevalence of plaque disruption is less than patients with ACS, these findings support the concept that some clinically stable patients may harbour 'silent' disrupted plaques. These findings may have implications for detection of 'at risk' plaques and patients.

Role of Intravascular Ultrasound in Patients with Acute Myocardial Infarction

Rupture of a vulnerable plaque and subsequent thrombus formation are important mechanisms leading to the development of an acute myocardial infarction (AMI). Typical intravascular ultrasound (IVUS) features of AMI include plaque rupture, thrombus, positive remodeling, attenuated plaque, spotty calcification, and thin-cap fibroatheroma. No-reflow phenomenon was attributable to the embolization of thrombus and plaque debris that results from mechanical fragmentation of the vulnerable plaque by percutaneous coronary intervention (PCI). Several grayscale IVUS features including plaque rupture, thrombus, positive remodeling, greater plaque burden, decreased post-PCI plaque volume, and tissue prolapse, and virtual histology-IVUS features such as large necrotic corecontaining lesion and thin-cap fibroatheroma were the independent predictors of no-reflow phenomenon in AMI patients. Non-culprit lesions associated with recurrent events were more likely than those not associated with recurrent events to be characterized by a plaque burden of ≥70%, a minimal luminal area of ≤4.0 mm(2), or to be classified as thin-cap fibroatheromas.

Comparison of plaque characteristics in narrowings with ST-elevation myocardial infarction (STEMI), non-STEMI/unstable angina pectoris and stable coronary artery disease (from the ADAPT-DES IVUS Substudy)

Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) was a prospective, multicenter registry of 8,582 consecutive stable and unstable patients who underwent percutaneous coronary intervention using a drug-eluting stent. We sought to identify key morphologic features leading to ST-segment elevation myocardial infarction (STEMI) versus non-STEMI (NSTEMI) or unstable angina pectoris (UA) versus stable coronary artery disease (CAD) presentation. In the prespecified grayscale and virtual histology (VH) substudy of ADAPT-DES, preintervention imaging identified 676 patients with a single culprit lesion. The relation between lesion morphology and clinical presentation was compared among patients with (1) STEMI, (2) NSTEMI or UA, and (3) stable CAD. Intravascular ultrasound identified more plaque rupture and VH thin-cap fibroatheroma (TCFA) in STEMI lesions compared with NSTEMI/UA or stable CAD lesions; conversely, fibroatheromas appeared more often calcified with a thick fibrous cap in stable CAD. Minimum lumen cross-sectional area (MLA) was smaller with larger plaque burden and positive remodeling in STEMI lesions. Lesions with plaque rupture versus those without plaque rupture showed higher prevalence of VH-TCFA and larger plaque burden with positive remodeling, especially in patients with STEMI. Multivariate analysis showed that in the lesions with plaque rupture, plaque burden at the MLA site was the only independent predictor for STEMI (cutoff of plaque burden = 85%) and in lesions without plaque rupture, MLA was the only independent predictor for STEMI (cutoff of MLA = 2.3 mm(2)). In conclusion, culprit lesions causing STEMI have smaller lumen areas, greater plaque burden, and more plaque rupture or VH-TCFA compared with NSTEMI/UA or stable CAD; in lesions with plaque rupture, only plaque burden predicted STEMI, and in lesions without plaque rupture, only MLA area predicted STEMI.

The serum protein fetuin-B is involved in the development of acute myocardial infarction

Fetuin-B was one of highly expressed serum proteins in AMI compared with stable angina. This protein affected vascular plaque-stabilizing components in monocytes, macrophages and vascular smooth muscle cells. Fetuin-B may be a possible contributor to AMI.

Plaque rupture and intact fibrous cap assessed by optical coherence tomography portend different outcomes in patients with acute coronary syndrome

AIMS

Patients presenting with acute coronary syndrome (ACS) may have different plaque morphologies at the culprit lesion. In particular, plaque rupture (PR) has been shown as the more frequent culprit plaque morphology in ACS. However, its prognostic value is still unknown. In this study, we evaluated the prognostic value of PR, compared with intact fibrous cap (IFC), in patients with ACS.

METHODS AND RESULTS

We enrolled consecutive patients admitted to our Coronary Care Unit for ACS and undergoing coronary angiography followed by interpretable optical coherence tomography (OCT) imaging. Culprit lesion was classified as PR and IFC by OCT criteria. Prognosis was assessed according to such culprit lesion classification. Major adverse cardiac events (MACEs) were defined as the composite of cardiac death, non-fatal myocardial infarction, unstable angina, and target lesion revascularization (follow-up mean time 31.58 ± 4.69 months). The study comprised 139 consecutive ACS patients (mean age 64.3 ± 12.0 years, male 73.4%, 92 patients with non-ST elevation ACS and 47 with ST-elevation ACS). Plaque rupture was detected in 82/139 (59%) patients. There were no differences in clinical, angiographic, or procedural data between patients with PR when compared with those having IFC. Major adverse cardiac events occurred more frequently in patients with PR when compared with those having IFC (39.0 vs. 14.0%, P = 0.001). Plaque rupture was an independent predictor of outcome at multivariable analysis (odds ratio 3.735, confidence interval 1.358-9.735).

CONCLUSION

Patients with ACS presenting with PR as culprit lesion by OCT have a worse prognosis compared with that of patients with IFC. This finding should be taken into account in risk stratification and management of patients with ACS.

Differences in intravascular ultrasound and histological findings in culprit coronary plaques between ST-segment elevation myocardial infarction and stable angina

A comprehensive evaluation of culprit coronary lesions may help to understand vulnerable plaques responsible for ST-segment elevation myocardial infarction (STEMI). We compared intravascular ultrasound (IVUS) and histological findings in culprit coronary plaques from 94 patients with STEMI (n = 54) or stable angina (n = 40). Tissue specimens were obtained by directional coronary atherectomy and IVUS was performed before percutaneous coronary intervention. IVUS and histological data were analyzed. Clinical characteristics were largely similar between the two groups. Plaque rupture and thrombi were more frequently found in the STEMI group than in the stable angina group. There were no significant differences between plaque types or proximal and distal reference measurements in the two groups. However, the site of minimal lumen area had a greater vessel area, remodeling index, and plaque burden with lesser lumen area in the STEMI group than in the stable angina group. Plaque areas immunopositive for CD68 and CD31 were significantly larger in the STEMI group, while the area immunopositive for α-smooth muscle actin was larger in the stable angina group. In conclusion, culprit lesions in STEMI patients showed a greater plaque burden, remodeling index, and more frequent thrombi with increased inflammation and neovascularization compared to the stable angina group, supporting the current concept of vulnerable plaques being responsible for STEMI.

Apolipoprotein B/apolipoprotein A1 ratio and non-high-density lipoprotein cholesterol. Predictive value for CHD severity and prognostic utility in CHD patients

BACKGROUND AND AIMS

To explore the clinical value of the combination of apolipoprotein B/apolipoprotein A1 (apoB/A1) and non-high-density lipoprotein cholesterol (HDL-C) in evaluating the severity of coronary heart disease (CHD) and in predicting in-hospital CHD events and the long-term prognosis of CHD patients.

METHODS

According to the results of coronary angiography, 826 patients were enrolled and classified into a CHD group (532 cases, including single-branch stenosis group, n = 165; double-branch stenosis group, n = 175;and multi-branch stenosis group, n = 192) and a normal group (294 cases). The serum apoB/apoA1 ratio and non-HDL-C were calculated at baseline. The Gensini score and logistic regression were applied to analyze the association between the apoB/apoA1 ratio, non-HDL-C, and the severity of CHD. Major in-hospital adverse incidents were recorded and follow-up telephone interviews were conducted 3 years after discharge.

RESULTS

Both the apoB/apoA1 ratio and non-HDL-C rose with the number of stenotic coronary branches. Only apoB and apoB/apoA1 remained significantly associated with the risk of multi-branches lesions and the Gensini score after adjustment. Patients with combined high levels of apoB/apoA1 and non-HDL-C (N = 50, 43.10 %) suffered from the highest risk of multi-branches lesions. Similarly, patients with combined high levels of apoB/apoA1 and non-HDL-C not only suffered from the highest risk of in-hospital new-onset heart failure and cardiac death (16.38 % vs. 10.35 %), but also had the highest risk of adverse events, angina, myocardial infarction, new-onset heart failure, stroke, and cardiac death after an average 3-year follow-up.

CONCLUSION

The combination of apoB/apoA1 and non-HDL-C is predictive of the severity of CHD, and it could provide more prognostic information than its individual components or other routine lipid profiles.

A comparison of tissue prolapse with optical coherence tomography and intravascular ultrasound after drug-eluting stent implantation

The aim of this study was to compare the detection rate of tissue prolapse (TP) in optical coherence tomography (OCT) and intravascular ultrasound (IVUS) after drug-eluting stent (DES) implantation and evaluate clinical implication of TP at 2 years after percutaneous coronary intervention. In spite of the superiority of OCT in the aspect of resolution when it was compared to IVUS, there was little data about the superiority of OCT in detecting TP. And there has been controversy about the clinical significance of TP. We enrolled 38 patients who treated with DES implantation. OCT and IVUS measurements were performed in stented segments immediately after percutaneous coronary intervention. We matched OCT and IVUS images one by one, and analyzed TP quantitatively in both measurements. Thirty patients (78.9 %) were followed-up for 2 years to evaluate clinical outcome of TP. TP was detected in 95 % of stented lesions by OCT and 45 % of stented lesions by IVUS among 40 stented lesions in 38 patients. The best cut-off values of the area, depth and burden of TP on OCT for the detection of TP on IVUS were 0.17 mm(2), 0.17 mm and 1.98 %, respectively. There was no statistically significant relation between TP and major adverse cardiac event during hospitalization and 2-year follow-up.

Imaging plaques to predict and better manage patients with acute coronary events

Culprit lesions of patients, who have had an acute coronary syndrome commonly, are ruptured coronary plaques with superimposed thrombus. The precursor of such lesions is an inflamed thin-capped fibroatheroma. These plaques can be imaged by means of invasive techniques, such as intravascular ultrasound (and derived techniques), optical coherence tomography, and near-infrared spectroscopy. Often these patients exhibit similar (multiple) plaques beyond the culprit lesion. These remote plaques can be assessed noninvasively by computed tomographic angiography and MRI and also using invasive imaging. The detection of these remote plaques is not only feasible but also in natural history studies have been associated with clinical coronary events. Different systemic pharmacological treatments have been studied (mostly statins) with modest success and, therefore, newer approaches are being tested. Local treatment for such lesions is in its infancy and larger, prospective, and randomized trials are needed. This review will describe the pathological and imaging findings in culprit lesions of patients with acute coronary syndrome and the assessment of remote plaques. In addition, the pharmacological and local treatment options will be reviewed.