Arterial remodeling and coronary artery disease: the concept of "dilated" versus "obstructive" coronary atherosclerosis

Tandem lesions associate with angiographic progression of coronary artery stenoses

Background

Although the clinical factors associated with progression of coronary artery disease have been well studied, the angiographic predictors are less defined.

Objectives

Our objective was to study the clinical and angiographic factors that associate with progression of coronary artery stenoses.

Methods

We conducted a retrospective analysis of consecutive patients undergoing multiple, clinically indicated invasive coronary angiograms with an interval greater than 6 months, between January 2013 and December 2016. Lesion segments were analysed using Quantitative Coronary Angiography (QCA) if a stenosis ≥ 20 % was identified on either angiogram. Stenosis progression was defined as an increase ≥ 10 % in stenosis severity, with progressor groups analysed on both patient and lesion levels. Mixed-effects regression analyses were performed to evaluate factors associated with progression of individual stenoses.

Results

199 patients were included with 881 lesions analysed. 108 (54.3 %) patients and 186 (21.1 %) stenoses were classified as progressors. The median age was 65 years (IQR 56-73) and the median interval between angiograms was 2.1 years (IQR 1.2-3.0). On a patient level, age, number of lesions and presence of multivessel disease at baseline were each associated with progressor status. On a lesion level, presence of a stenosis downstream (OR 3.07, 95 % CI 2.04-4.63, p < 0.001) and circumflex artery stenosis location (OR 1.81, 95 % CI 1.21-2.7, p = 0.004) were associated with progressor status. Other lesion characteristics did not significantly impact progressor status or change in stenosis severity.

Conclusion

Coronary lesions which have a downstream stenosis may be at increased risk of stenosis progression. Further research into the mechanistic basis of this finding is required, along with its implications for plaque vulnerability and clinical outcomes.

A review of the conservative versus invasive management of ischemic heart failure with reduced ejection fraction

Heart failure is increasing in terms of prevalence, morbidity, and mortality rates. Clinical trials and studies are focusing on heart failure as it is the destiny end-stage for several cardiovascular disorders. Recently, medical therapy has dramatically progressed with novel classes of medicines providing better quality of life and survival outcomes. However, heart failure remains a heavy impactful factor on societies and populations. Current guidelines from the American and European cardiac societies are not uniform with respect to the class and level of treatment recommendations for coronary artery disease patients with heart failure and reduced ejection fraction. The discrepancy among international recommendations, stemming from the lack of evidence from adequately powered randomized trials, challenges physicians in choosing the optimal strategy. Hybrid therapy including optimal medical therapy with revascularization strategies are commonly used for the management of ischemic heart failure. Coronary artery bypass graft (CABG) has proved its efficacy on improving long term outcome and prognosis while no large randomized clinical trials for percutaneous coronary intervention (PCI) are still available. Regardless of the lack of data and recommendations, the trends of performing PCI in ischemic heart failure prevailed over CABG whereas lesion complexity, chronic total occlusion and complete revascularization achievement are limiting factors. Lastly, regenerative medicine seems a promising approach for advanced heart failure enhancing cardiomyocytes proliferation, reverse remodeling, scar size reduction and cardiac function restoration.

Characteristics of intracranial plaque in patients with non-cardioembolic stroke and intracranial large vessel occlusion

OBJECTIVE

To determine the characteristics of intracranial plaque proximal to large vessel occlusion (LVO) in stroke patients without major-risk cardioembolic source using 3.0 T high-resolution MRI (HR-MRI).

METHODS

We retrospectively enrolled eligible patients from January 2015 to July 2021. The multidimensional parameters of plaque such as remodelling index (RI), plaque burden (PB), percentage lipid-rich necrotic core (%LRNC), presence of discontinuity of plaque surface (DPS), fibrous cap rupture, intraplaque haemorrhage and complicated plaque were evaluated by HR-MRI.

RESULTS

Among 279 stroke patients, intracranial plaque proximal to LVO was more prevalent in the ipsilateral versus contralateral side to stroke (75.6% vs 58.8%, p<0.001). The larger PB (p<0.001), RI (p<0.001) and %LRNC (p=0.001), the higher prevalence of DPS (61.1% vs 50.6%, p=0.041) and complicated plaque (63.0% vs 50.6%, p=0.016) were observed in the plaque ipsilateral versus contralateral to stroke. Logistic analysis showed that RI and PB were positively associated with an ischaemic stroke (RI: crude OR: 1.303, 95% CI 1.072 to 1.584, p=0.008; PB: crude OR: 1.677, 95% CI 1.381 to 2.037, p<0.001). In subgroup with <50% stenotic plaque, the greater PB, RI, %LRNC and the presence of complicated plaque were more closely related to stroke, which was not evident in subgroup with ≥50% stenotic plaque.

CONCLUSION

This is the first study to report the characteristics of intracranial plaque proximal to LVO in non-cardioembolic stroke. It provides potential evidence to support different aetiological roles of <50% stenotic vs ≥50% stenotic intracranial plaque in this population.

What eyes do not see the heart does not grieve over? The role of intracoronary imaging in acute myocardial infarction: a case report

Background

The evaluation of a three-dimensional structure with a two-dimensional imaging technique makes intracoronary diagnostic techniques essential, especially in the setting of acute myocardial infarction (AMI) when no apparent coronary lesions are detected. Expert consensus recommend their use in certain scenarios such as angiographically ambiguous disease and identification of the culprit lesion. Although both intravascular ultrasound and optical coherence tomography (OCT) allow the characterization of the atherosclerotic plaque and assess the immediate and long-term results of stent implantation, they have their own benefits and limitations that make them ideal for different types of coronary lesions.

Case summary

We present the case of a lateral ST-elevation myocardial infarction with no evident coronary lesions in angiography, in which OCT not only allowed us to confirm a diagonal branch occlusion, but it also became crucial to locate the occlusion point and to guide the procedure, allowing complete revascularization of the culprit lesion that otherwise could have been missed.

Discussion

To know the actual limitations of conventional coronary angiography to adequately assess coronary disease, intracoronary diagnostic techniques are key to evaluate the underlying mechanisms of the event, especially in the setting of AMI when no clear culprit lesion has been identified. They can be of great value to locate and revascularize acute occlusions that could go unnoticed on the angiogram, guiding the revascularization and stent implantation and, therefore, preventing myocardial injury that could become irreversible when coronary disease is not treated promptly.

Experimental Liver Cirrhosis Inhibits Restenosis after Balloon Angioplasty

The effect of liver cirrhosis on vascular remodeling in vivo remains unknown. Therefore, this study investigates the influence of cholestatic liver cirrhosis on carotid arterial remodeling. A total of 79 male Sprague Dawley rats underwent bile duct ligation (cirrhotic group) or sham surgery (control group) and 28 days later left carotid artery balloon dilatation; 3, 7, 14 and 28 days after balloon dilatation, the rats were euthanized and carotid arteries were harvested. Histological sections were planimetrized, cell counts determined, and systemic inflammatory parameters measured. Up to day 14 after balloon dilatation, both groups showed a comparable increase in neointima area and degree of stenosis. By day 28, however, both values were significantly lower in the cirrhotic group (% stenosis: 20 ± 8 vs. 42 ± 10, p = 0.010; neointimal area [mm²]: 0.064 ± 0.025 vs. 0.138 ± 0.025, p = 0.024). Simultaneously, cell density in the neointima (p = 0.034) and inflammatory parameters were significantly higher in cirrhotic rats. This study demonstrates that cholestatic liver cirrhosis in rats substantially increases neointimal cell consolidation between days 14 and 28. Thereby, consolidation proved important for the degree of stenosis. This may suggest that patients with cholestatic cirrhosis are at lower risk for restenosis after coronary intervention.

Vulnerable plaque of the petrous internal carotid artery in embolic stroke of undetermined source

BACKGROUND AND PURPOSE

The association between nonstenotic plaque at the petrous internal carotid artery (ICA) and embolic stroke of undetermined source (ESUS) remains unknown. We aimed to test the hypothesis that the presence of a larger build-up of petrous plaque is more prevalent in the ipsilateral versus the contralateral side among ESUS patients without plaque in the intracranial and proximal ICA.

METHODS

From a total of 243 patients with ESUS and 160 patients with small-vessel disease (SVD) without proximal ICA plaque, we enrolled 88 ESUS and 103 SVD patients without ipsilateral nonstenotic intracranial and proximal ICA plaque in the present study. Targeting the petrous segment of the ICA on two sides, plaque burden including plaque thickness, lumen area, vessel area, wall area, and percentage of luminal stenosis, and composition features (presence/absence of the ruptured fibrous cap, ulcer plaque, thrombus, discontinuity of plaque surface [DPS], intraplaque hemorrhage and complicated plaque) were assessed by high-resolution magnetic resonance imaging.

RESULTS

We found a higher prevalence of petrous plaque thickness ≥3.5 mm ipsilateral versus contralateral to the stroke (25/88 [28.4%] vs. 12/88 [13.6%], odds ratio [OR] 3.60, 95% confidence interval [CI] 1.34-9.70), but this imbalance was not seen in SVD. In patients with plaque thickness ≥3.5 mm, the presence of DPS (OR 4.05, 95% CI 1.11-14.78) and complicated plaque (OR 5.00, 95% CI 1.10-22.82) was more closely related to an index ESUS, a finding that was not evident in the subgroup with petrous plaque <3.5 mm (p for interaction = 0.027).

CONCLUSIONS

The present study provided the first evidence supporting a potential etiological role of vulnerable petrous plaque in ESUS.

A review of cardio-pulmonary microvascular dysfunction in pulmonary hypertension

Microvascular dysfunction progressing to pulmonary hypertension can be a primary cause of right ventricular failure or a secondary cause because of an underlying systemic illness. Little is known regarding the etiology and epidemiology of coronary microvascular dysfunction in pulmonary hypertension. Despite this limitation, its presence has been described in patients with pulmonary hypertension. This review focuses on the pathogenesis of cardiac and pulmonary microvascular dysfunction in pulmonary hypertension. Additionally, this review provides a contemporary assessment on the diagnosis and treatment of microvascular dysfunction in patients in pulmonary hypertension. This topic is important to raise awareness of microvascular dysfunction in the coronary and pulmonary circulation, so that future studies will investigate its impact on the pulmonary hypertension patient cohort.

Imaging subclinical coronary atherosclerosis to guide lipid management, are we there yet?

Atherosclerotic cardiovascular disease risk (ASCVD) is an ongoing epidemic, and lipid abnormalities are its primordial cause. Most individuals suffering a first ASCVD event are previously asymptomatic and often do not receive preventative therapies. The cornerstone of primary prevention has been the identification of individuals at risk through risk calculators based on clinical and laboratory traditional risk factors plus risk enhancers. However, it is well accepted that a clinical risk calculator misclassifies a significant proportion of individuals leading to the prescription of a lipid-lowering medication with very little yield or a missed opportunity for lipid-lowering agents with a potentially preventable event. The development of coronary artery calcium scoring (CAC) and CT coronary angiography (CCTA) provide complementary tools to directly visualize coronary plaque and other risk-modifying imaging components that can potentially provide individualized lipid management. Understanding patient selection for CAC or potentially CCTA and the risk implications of the different parameters provided, such as CAC score, coronary stenosis, plaque characteristics and burden, epicardial adipose tissue, and pericoronary adipose tissue, have grown more complex as technologies evolve. These parameters directly affect the shared decision with patients to start or withhold lipid-lowering therapies, to adjust statin intensity or LDL cholesterol goals. Emerging lipid lowering studies with non-invasive imaging as a guide to patient selection and treatment efficacy, plus the evolution of lipid lowering therapies from statins to a diverse armament of newer high-cost agents have pushed these two fields forward with a complex interaction. This review will discuss existing risk estimators, and non-invasive imaging techniques for subclinical coronary atherosclerosis, traditionally studied using CAC and more recently CCTA with qualitative and quantitative measurements. We will also explore the current data, gaps of knowledge and future directions on the use of these techniques in the risk-stratification and guidance of lipid management.

Procedural Outcomes After Percutaneous Coronary Interventions in Focal and Diffuse Coronary Artery Disease

Background Coronary artery disease (CAD) patterns play an essential role in the decision-making process about revascularization. The pullback pressure gradient (PPG) quantifies CAD patterns as either focal or diffuse based on fractional flow reserve (FFR) pullbacks. The objective of this study was to evaluate the impact of CAD patterns on acute percutaneous coronary intervention (PCI) results considered surrogates of clinical outcomes. Methods and Results This was a prospective, multicenter study of patients with hemodynamically significant CAD undergoing PCI. Motorized FFR pullbacks and optical coherence tomography (OCT) were performed before and after PCI. Post-PCI FFR >0.90 was considered an optimal result. Focal disease was defined as PPG >0.73 (highest PPG tertile). Overall, 113 patients (116 vessels) were included. Patients with focal disease were younger than those with diffuse CAD (61.4±9.9 versus 65.1±8.7 years, P=0.042). PCI in vessels with high PPG (focal CAD) resulted in higher post-PCI FFR (0.91±0.07 in the focal group versus 0.86±0.05 in the diffuse group, P<0.001) and larger minimal stent area (6.3±2.3 mm² in focal versus 5.3±1.8 mm² in diffuse CAD, P=0.015) compared withvessels with low PPG (diffuse CAD). The PPG was associated with the change in FFR after PCI (R²=0.51, P<0.001). The PPG significantly improved the capacity to predict optimal PCI results compared with an angiographic assessment of CAD patterns (area under the curve_PPG 0.81 [95% CI, 0.73-0.88] versus area under the curve_angio 0.51 [95% CI, 0.42-0.60]; P<0.001). Conclusions PCI in vessels with focal disease defined by the PPG resulted in greater improvement in epicardial conductance and larger minimal stent area compared with diffuse disease. PPG, but not angiographically defined CAD patterns, distinguished patients attaining superior procedural outcomes. Registration URL: https://clinicaltrials.gov/ct2/show/NCT03782688.

Traditional and novel diagnostic biomarkers for acute myocardial infarction

Background

Acute myocardial infarction (AMI) is a leading cause of death worldwide. The first hours of acute myocardial infarction are correlated with the highest risk of death. Therefore, early diagnosis of the infarction seriously affects the efficacy of the treatment administered to the patient. Misdiagnosing patients with chest pain often leads to inappropriate admission of them as acute myocardial infarction patients. The physical examination of the patient, the electrocardiogram, and the assessment of cardiac biomarkers all play an important role in the early diagnosis of acute ischemia, along with the patient's medical history.

Main body

The present review highlights a number of different biomarkers that are released and elevated in blood during an acute myocardial infarction.

Conclusions

Analysis of cardiac biomarkers has become the first-line diagnostic tool used in the diagnosis of acute myocardial infarction. Novel markers of acute myocardial infarction, when added to routinely used markers, can provide added value not only in the earlier detection of acute myocardial infarction but also in monitoring the clinical progress of the disease, predicting its consequences, evaluating its prognosis, detecting recurrence, and managing its treatment. This leads to a lower mortality rate associated with acute myocardial infarction.

cMyC, IMA, S100, and MicroRNAs can serve as markers of early diagnosis of acute myocardial infarction, whereas myeloperoxidase, sCD40L, PAPPA, and TNF-α can be used to monitor the clinical progress of the disease. In addition, H-FABP, GDF-15, F2 isoprostanes, and ST2 can serve as predictors of AMI complications and mortality. Copeptin, ST2, and SIRT can be useful as prognostic markers of acute myocardial infarction.

Cardiovascular risk stratification by coronary computed tomography angiography imaging: current state-of-the-art

Current cardiovascular risk stratification by use of clinical risk score systems or plasma biomarkers is good but less than satisfactory in identifying patients at residual risk for coronary events. Recent clinical evidence puts now further emphasis on the role of coronary anatomy assessment by coronary computed tomography angiography (CCTA) for the management of patients with stable ischaemic heart disease. Available computed tomography (CT) technology allows the quantification of plaque burden, identification of high-risk plaques, or the functional assessment of coronary lesions for ischaemia detection and revascularization for refractory angina symptoms. The current CT armamentum is also further enhanced by perivascular Fat Attenuation Index (FAI), a non-invasive metric of coronary inflammation, which allows for the first time the direct quantification of the residual vascular inflammatory burden. Machine learning and radiomic features' extraction and spectral CT for tissue characterization are also expected to maximize the diagnostic and prognostic yield of CCTA. The combination of anatomical, functional, and biological information on coronary circulation by CCTA offers a unique toolkit for the risk stratification of patients, and patient selection for targeted aggressive prevention strategies. We hereby provide a review of the current state-of-the art in the field and discuss how integrating the full capacities of CCTA into clinical care pathways opens new opportunities for the tailored management of coronary artery disease.

Dual-energy CT plaque characteristics of post mortem thin-cap fibroatheroma in comparison to infarct-related culprit lesions

Improvement of non-invasive identification of high-risk plaque may increase the preventive options of acute coronary syndrome. To describe the characteristics of thin-cap fibroatheroma (TCFA) in a post mortem model in comparison to characteristics of culprit lesions in patients with non-ST-elevation-myocardial-infarction (NSTEMI) using the dual energy computed tomography (DECT). Three post mortem hearts were prepared with iodine-contrast, inserted in a Kyoto phantom and scanned by DECT. Six TCFA were identified using histopathological analysis (cap thickness < 65 μm and necrotic core > 10% of the plaque area). In the NSTEMI group, 29 patients were scheduled to DECT prior to coronary angiography and invasive treatment. Culprit lesions were identified blinded for the patient history by two independent invasive cardiologists using the coronary angiography. The DECT analysis of TCFA and culprit lesions was performed retrospectively with determination of effective atomic number (Effective-Z), Hounsfield Unit (HU), plaque type (non-calcified, predominantly non-calcified, predominantly calcified or calcified), spotty calcification,, plaque length, plaque volume and plaque burden and the remodeling index. The Effective-Z, HU and plaqueburden were significantly different between TCFA and culprit lesions (P < 0.05).The TCFA plaques were more calcified in comparison to culprit lesions (P < 0.05). No significant difference in the other plaque characteristics was observed. The use of DECT demonstrated different Effective-Z values and different characteristics of post mortem TCFA in comparison to in vivo culprit lesions. This finding may highlight, that not all TCFA should be considered as vulnerable.

High-risk coronary plaque in SLE: low-attenuation non-calcified coronary plaque and positive remodelling index

Background

Positive remodelling index and presence of low-attenuation non-calcified plaque (LANCP) are characteristic vessel changes in unstable coronary plaques. We sought to characterise these high-risk plaque features in patients with systemic lupus erythematosus (SLE) and to compare them with controls.

Methods

A total of 72 patients who satisfied the SLICC classification criteria for SLE had coronary CT angiography (CCTA) studies, 30 of which had follow-up CCTA, as screening for occult coronary atherosclerotic disease in asymptomatic individuals. A total of 100 consecutive controls with no known history of lupus, heart disease or revascularisation who had two coronary CT angiograms at least 1 year apart were included in the study. These were asymptomatic patients referred by their primary physicians for screening of coronary artery disease and the screening interval was decided by the primary physicians. The methodology for image acquisition was identical.

Results

LANCP burden at baseline was significantly greater in patients with SLE compared with controls. LANCP volume was significantly greater in patients over 60 years of age (p<0.05) and in those with current prednisone dose >10 mg/day. LANCP burden remained stable over follow-up. There were no significant differences in remodelling index compared with controls.

Conclusion

This is the first study describing high-risk CCTA features of coronary plaque in patients with SLE. Both LANCP and positive remodelling are common in SLE. These characteristic vessel changes may identify patients with SLE at increased risk of cardiovascular events and those in need for more frequent cardiac monitoring.

Measurement of compensatory arterial remodelling over time with serial coronary computed tomography angiography and 3D metrics

AIMS

The magnitude of alterations in which coronary arteries remodel and narrow over time is not well understood. We aimed to examine changes in coronary arterial remodelling and luminal narrowing by three-dimensional (3D) metrics from serial coronary computed tomography angiography (CCTA).

METHODS AND RESULTS

From a multicentre registry of patients with suspected coronary artery disease who underwent clinically indicated serial CCTA (median interscan interval = 3.3 years), we quantitatively measured coronary plaque, vessel, and lumen volumes on both scans. Primary outcome was the per-segment change in coronary vessel and lumen volume from a change in plaque volume, focusing on arterial remodelling. Multivariate generalized estimating equations including statins were calculated comparing associations between groups of baseline percent atheroma volume (PAV) and location within the coronary artery tree. From 1245 patients (mean age 61 ± 9 years, 39% women), a total of 5721 segments were analysed. For each 1.00 mm3 increase in plaque volume, the vessel volume increased by 0.71 mm3 [95% confidence interval (CI) 0.63 to 0.79 mm3, P < 0.001] with a corresponding reduction in lumen volume by 0.29 mm3 (95% CI -0.37 to -0.21 mm3, P < 0.001). Serial 3D arterial remodelling and luminal narrowing was similar in segments with low and high baseline PAV (P ≥ 0.496). No differences were observed between left main and non-left main segments, proximal and distal segments and side branch and non-side branch segments (P ≥ 0.281).

CONCLUSIONS

Over time, atherosclerotic coronary plaque reveals prominent outward arterial remodelling that co-occurs with modest luminal narrowing. These findings provide additional insight into the compensatory mechanisms involved in the progression of coronary atherosclerosis.

Impact of monocyte to high-density lipoprotein ratio on the identification of prevalent coronary heart disease: insights from a general population

BACKGROUND

Recent studies have identified monocyte to high-density lipoprotein ratio (MHR) as a simple, practical surrogate of atherosclerosis. Considering atherosclerosis is a major mechanism of coronary heart disease (CHD). The present study aims to evaluate the association between MHR and the prevalence of CHD.

METHODS AND RESULTS

The present cross-sectional work included 6442 participants (mean age: 59.57 years, 60.2% females), all of them were included from rural areas of northern China between October 2019 to April 2020. MHR was acquired as monocytes count divided by high-density lipoprotein concentration. Prevalent CHD researched 3.14%. After adjustment of sex, age, current drinking and smoking, BMI, WC, diabetes, hypertension, LDL-C, TG, eGFR, lipid-lowering therapy and cerebrovascular disease history, each standard deviation increase of MHR cast a 39.5% additional CHD risk. Furthermore, the top quartile of MHR had an additional 89.0% CHD risk than the bottom quartile. Besides, smooth curve fitting revealed a linear pattern of the association. Additionally, the stratified evaluation showed a robust correlation among the subgroups divided by CHD risk factors. Finally, area under the curve demonstrated an advancement when including MHR into common CHD risk factors (0.744 vs 0.761, p < 0.001). Consistently, reclassification analysis indicated the improvement from MHR (all P = 0.003).

CONCLUSION

Our work suggests the robust and linear relationship between MHR and the prevalent CHD in a general population, providing epidemiological evidence for laboratory studies. More importantly, the findings implicate the efficacy of MHR to be a potential indicator to identify the prevalent CHD.

Role of Brain Arterial Remodeling in HIV-Associated Cerebrovascular Outcomes

As the life expectancy of people living with HIV (PLWH) on combination antiretroviral therapy (cART) increases, so does morbidity from cerebrovascular disease and neurocognitive disorders. Brain arterial remodeling stands out as a novel investigational target to understand the role of HIV in cerebrovascular and neurocognitive outcomes. We therefore conducted a review of publications in PubMed, EMBASE, Web of Science and Wiley Online Library, from inception to April 2021. We included search terms such as HIV, cART, brain, neuroimmunity, arterial remodeling, cerebrovascular disease, and neurocognitive disorders. The literature shows that, in the post-cART era, PLWH continue to experience an increased risk of stroke and neurocognitive disorders (albeit milder forms) compared to uninfected populations. PLWH who are immunosuppressed have a higher proportion of hemorrhagic strokes and strokes caused by opportunistic infection and HIV vasculopathy, while PLWH on long-term cART have higher rates of ischemic strokes, compared to HIV-seronegative controls. Brain large artery atherosclerosis in PLWH is associated with lower CD4 nadir and higher CD4 count during the stroke event. HIV vasculopathy, a form of non-atherosclerotic outward remodeling, on the other hand, is associated with protracted immunosuppression. HIV vasculopathy was also linked to a thinner media layer and increased adventitial macrophages, suggestive of non-atherosclerotic degeneration of the brain arterial wall in the setting of chronic central nervous system inflammation. Cerebrovascular architecture seems to be differentially affected by HIV infection in successfully treated versus immunosuppressed PLWH. Brain large artery atherosclerosis is prevalent even with long-term immune reconstitution post-cART. HIV-associated changes in brain arterial walls may also relate to higher rates of HIV-associated neurocognitive disorders, although milder forms are more prevalent in the post-cART era. The underlying mechanisms of HIV-associated pathological arterial remodeling remain poorly understood, but a role has been proposed for chronic HIV-associated inflammation with increased burden on the vasculature. Neuroimaging may come to play a role in assessing brain arterial remodeling and stratifying cerebrovascular risk, but the data remains inconclusive. An improved understanding of the different phenotypes of brain arterial remodeling associated with HIV may reveal opportunities to reduce rates of cerebrovascular disease in the aging population of PLWH on cART.

Impact of Arterial Remodeling of Intermediate Coronary Lesions on Long-Term Clinical Outcomes in Patients with Stable Coronary Artery Disease: An Intravascular Ultrasound Study

Background

Treatment of coronary intermediate lesions remains a controversy, and the role of arterial remodeling patterns determined by intravascular ultrasound in intermediate lesion is still not well known. The aim of this study was to investigate the impact of arterial remodeling of intermediate coronary lesions on long-term clinical outcomes.

Methods

Arterial remodeling patterns were assessed in 212 deferred intermediate lesions from 162 patients after IVUS examination. Negative, intermediate, and positive remodeling was defined as a remodeling index of <0.88, 0.88∼1.0, and >1.0, respectively. The primary endpoint was the composite vessel-oriented clinical events, defined as the composition of target vessel-related cardiac death, target vessel-related myocardial infarction, and target vessel revascularization. Quantitative flow ratio was assessed for evaluating the functional significance of intermediate lesions.

Results

72 intermediate remodeling lesions were present in 66 patients, whereas 77 negative remodeling lesions were present in 71 patients, and 63 positive remodeling lesions were present in 55 patients. Negative remodeling lesions had the smallest minimum lumen area (4.16 ± 1.03 mm² vs. 5.05 ± 1.39 mm² vs. 4.85 ± 1.76 mm²; P < 0.01), smallest plaque burden (63.45 ± 6.13% vs. 66.12 ± 6.82% vs. 71.17 ± 6.45%; P < 0.01), and highest area stenosis rate (59.32% ± 10.15% vs. 54.61% ± 9.09% vs. 51.67% ± 12.96%; P < 0.01). No significant difference was found in terms of quantitative flow ratio among three groups. At 5 years follow-up, negative remodeling lesions had a higher rate of composite vessel-oriented clinical event (14.3%), compared to intermediate (1.4%, P=0.004) or positive remodeling lesions (4.8%, P=0.06). After adjusting for multiple covariates, negative remodeling remained an independent determinant for vessel-oriented clinical event (HR: 4.849, 95% CI 1.542-15.251, P=0.007).

Conclusion

IVUS-derived negative remodeling is associated with adverse long-term clinical outcome in stable patients with intermediate coronary artery stenosis.

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.

The Role of Angiotensin Antagonism in Coronary Plaque Regression: Insights from the Glagovian Model

The benefit of antagonizing the effect of the renin angiotensin aldosterone system (RAAS), notably by the use of angiotensin-converting enzyme inhibitor (ACEi) and angiotensin II type 1 receptor blocker (ARB) for coronary artery disease (CAD), has been demonstrated in multiple studies, which may be attributed to their ability to inhibit the deleterious effect of RAAS to the cardiovascular system. It is well known that angiotensin II (Ang II) plays a vital role in atheromatous plaque formation and progression through multiple pathways, including inflammatory and arterial remodeling aspects. Significant coronary atheromatous plaque regression has been previously demonstrated in various studies using statin agents. Similar results have been reported in different studies using angiotensin inhibitor agents, notably ARB agents. Analysis from various trials utilizing ARB showed a significant plaque regression using olmesartan and telmisartan as evaluated by IVUS studies. In contrary, the use of ACEi did not demonstrated significant plaque regression, which may be attributed to the heavy plaque calcification in respective studies. On this review, we aim to present the basic mechanism on the role of RAAS in plaque modulation and its arterial remodeling aspect, which is then integrated with the clinical evidence based on the available intravascular ultrasonography (IVUS) studies on coronary arteries.

Positive Remodeling – a Major Feature of Vulnerability in Patients with Non-Obstructive Coronary Artery Disease

The most common cause of acute coronary syndrome is thrombosis of an atheromatous plaque. Positive remodeling is the compensatory dilatation of the plaque-containing section of the vessel wall. Plaques are most commonly characterized as vulnerable when possessing some of the following features: fibrous cap thickness <65 µm, large necrotic lipid core, high degrees of inflammatory infiltrates, positive remodeling, intraplaque hemorrhage, or neoangio-genesis. The presence of these plaque features is associated with high cardiovascular risk. In the initial stage of vasculopathy, due to positive remodeling, lumen reduction is not typical; it only develops in the advanced phase of the disease, due to which, based on a lumenogram, the vascular system may appear intact. Therefore, coronary angiography can easily miss the diagnosis or underestimate its extent, since it does not inform us of the composition of the arterial wall, because the contrast agent is just filling the vessel lumen. Coronary CT angiography may fill this diagnostic gap, since changes of the vessel wall can directly be visualized. To increase diagnostic accuracy, invasive coronary angiography can be completed by intravascular ultrasound and optical coherence tomography.

Atherosclerotic Carotid Plaque Composition and Incident Stroke and Coronary Events

BACKGROUND

Increasing evidence suggests that atherosclerotic plaque composition rather than plaque size is linked to ischemic cardiovascular events, yet largescale population-based data in asymptomatic individuals remain scarce.

OBJECTIVES

This study sought to investigate carotid plaque composition in relation to incident stroke and coronary heart disease (CHD) in a population-based setting.

METHODS

Between 2007 and 2012, 1,349 persons (mean age 72 years, 49.5% women) from the population-based Rotterdam Study who were free from a history of stroke or CHD, in whom carotid ultrasonography showed subclinical atherosclerosis, and who underwent high-resolution magnetic resonance imaging of the carotid arteries to assess plaque characteristics. These included the presence of specific plaque components (intraplaque hemorrhage [IPH], lipid-rich necrotic core, and calcification), and measures of plaque size (maximum plaque thickness and presence of stenosis of more than 30%). Individuals were continuously followed for the occurrence of stroke or CHD until January 1, 2015. The authors used Cox regression models to assess the association of the plaque characteristics with the incidence of stroke and CHD, with adjustments for age, sex, and cardiovascular risk factors.

RESULTS

During a median of 5.1 years' follow-up for stroke and 4.8 years for CHD, 51 individuals had a stroke and 83 developed CHD. Independent of maximum plaque thickness and cardiovascular risk factors, the presence of IPH was associated with incident stroke and CHD (fully adjusted hazard ratio: 2.42 [95% confidence interval: 1.30 to 4.50], and 1.95 [95% confidence interval: 1.20 to 3.14]). Presence of a lipid-rich necrotic core and calcification were not associated with stroke or CHD.

CONCLUSIONS

The presence of IPH in the carotid atherosclerotic plaque is an independent risk factor for stroke and CHD. These findings indicate the promise of IPH as a marker of plaque vulnerability in healthy persons with subclinical atherosclerosis.

Fatal coronary ectasia: An autopsy case report and review of literature

Coronary ectasia is a rare vessel defect that represents a pathological and incidental finding in routine coronary angiography performed for other coronary syndromes. This defect exposes to the risk of intra-coronary thrombosis by blood stasis due to the turbulent blood flow in those dilated areas that can lead to sudden death. We report an autopsy case of a male subject suddenly deceased. A medico-legal autopsy concluded an ischemic heart failure due to a vascular thrombosis by a blood clot in a coronary ectasia. Our case report aimed to discuss the mechanisms of sudden death attributed to coronary artery ectasia.

Reliability of coronary computed tomography angiography in acute coronary syndrome in an emergency setting

Background

Cardiovascular computed tomography (cardiovascular CT) is currently used as a fast non-invasive method for the visualization of coronary plaques and walls and the assessment of lumen stenosis severity. Previous studies demonstrated the high negative predictive value of CT for the exclusion of coronary lumen stenoses. In this study we hypothesize that coronary CT angiography (CTA) represents a reliable method as diagnostic procedure in acute coronary syndrome (ACS) even in emergency settings.

Methods

36 patients (51 lesions) with ACS who underwent cardiovascular CT, intravascular ultrasound (IVUS) and invasive coronary angiography (ICA) within 48 h were included. The percentage of coronary stenoses were measured and compared by three methods. Influence of available predictors that can potentially affect the measurement results was assessed.

Results

Cardiac CTA provided comparable results to IVUS (mean difference -0.45%, PPV: 98%, NPV: 75%). ICA tends to estimate lower stenoses degrees than cardiac CTA and IVUS (mean difference 13.19% and 13.64%, respectively). The final diagnosis and positive remodeling did not lead to any significant influence on measurements.

Conclusions

The cardiovascular CT results show that even in emergency settings it is possible to identify morphological changes as sequels of coronary artery sclerosis with comparable results to the reference method IVUS. Deviations of IVUS and cardiovascular CT from ICA are comparable and can to a large extent be explained by differences in the measurement technique.

Characteristics of culprit lesion in patients with non-ST-elevation myocardial infarction and improvement of diagnostic utility using dual energy cardiac CT

AIMS

The aim of the study was to identify the characteristics of the culprit lesions compared to non-culprit lesions in patients with non-ST-elevation-myocardial infarction using dual energy computed tomography (DECT).

METHODS AND RESULTS

In 29 patients, we identified 29 culprit lesions and 227 non-culprit lesions. Quantitative values such as the effective atomic number (effective-Z) and Hounsfield Units (HU) values were measured. Furthermore, all the lesions were characterised using characteristics such as composition (non-calcified, predominantly-non-calcified, predominantly-calcified, or calcified), presence of spotty calcification, remodelling index, and napkin ring sign. The mean effective-Z and HU values were significantly lower in culprit lesions than in non-culprit lesions (8.99 ± 1.21 vs 9.79 ± 1.52; p = 0.0066 and 87.41 ± 84.97 vs. 154.45 ± 176.13; p = 0.0447). The culprit lesions had a higher frequency of non-calcified plaques and predominantly non-calcified plaques, and were with a greater presence of napkin ring signs in comparison with non-culprit lesions. There were no differences in the presence of spotty calcification or remodelling index. By adding effective-Z to plaque characteristics such as non-calcified, positive remodelling, spotty calcification, and napkin rings we observed a significant increased sensitivity of detecting culprit lesions (65.5% vs.44.8%), but no significant changes in area under curve (AUC).

CONCLUSION

The use of DECT adds new information of the plaque composition expressed by the effective-Z, which differs significantly in culprit lesions in comparison with non-culprit lesions. The use of the effective-Z improves the diagnostic sensitivity in detection of culprit lesions.

Quantitative and Qualitative Analysis of Atherosclerotic Stenosis in the Middle Cerebral Artery Using High-Resolution Magnetic Resonance Imaging

PURPOSE

We analyzed and compared the imaging characteristics of the vessel wall of the middle cerebral artery (MCA) in symptomatic and asymptomatic patients using a 3.0-T high-resolution magnetic resonance imaging (HR-MRI) protocol, including a 3-dimensional T1-sampling perfection with application-optimized contrasts using different flip angle evolutions sequence.

METHODS

Fifty-three patients with atherosclerotic stenosis of the MCA underwent 3.0-T HR-MRI examinations. The characteristics of atherosclerotic plaques in 53 patients (28 symptomatic, 25 asymptomatic) were analyzed, including plaque distribution and signal intensity. Plaque burden (PB), stenosis degree, and the remodeling index were measured and compared between symptomatic and asymptomatic patients.

RESULTS

The PB of the symptomatic group was significantly higher than that of the asymptomatic group (P = .006), and moderate-severe stenosis was more common (P = .01). The remodeling index of the symptomatic group was also lower (P = .015) and negative remodeling (NR) was more common (P = .043). Binary logistic regression analysis showed that stenosis degree was a risk factor in symptomatic patients (odds ratio = 135, P = .023).

CONCLUSION

There is a trend that some characteristics of plaques and vessels, including the moderate-severe stenosis, larger PB, and NR, were observed more frequently among patients with symptomatic atherosclerotic stenosis of the MCA than among asymptomatic patients.

Relationship between arterial remodelling and serial changes in coronary atherosclerosis by intravascular ultrasound: an analysis of the IBIS-4 study

AIMS

Arterial remodelling is an important determinant of coronary atherosclerosis. Assessment of the remodelling index, comparing a lesion to a local reference site, is a suboptimal correlate of serial vascular changes. We assessed a novel approach which, unlike the local-reference approach, uses the entire artery's global remodelling as reference.

METHODS AND RESULTS

Serial (baseline and 13 months) intravascular ultrasound was performed in 146 non-infarct-related arteries of 82 patients treated with high-intensity statin. Arteries were divided into 3-mm segments (n = 1479), and focal remodelling was characterized in individual segments at both timepoints applying the global arterial reference approach. First, we compared preceding vascular changes in relation to follow-up remodelling. Second, we examined whether baseline remodelling predicts subsequent plaque progression/regression. At follow-up, segments with constrictive vs. compensatory or expansive remodelling had greater preceding reduction of vessel area (-0.67 vs. -0.38 vs. -0.002 mm2; P < 0.001) and lumen area (-0.82 vs. -0.09 vs. 0.40 mm2; P < 0.001). Overall, we found significant regression in percent atheroma volume (PAV) [-0.80% (-1.41 to -0.19)]. Segments with constrictive remodelling at baseline had greater subsequent PAV regression vs. modest regression in the compensatory, and PAV progression in the expansive remodelling group (-6.14% vs. -0.71% vs. 2.26%; P < 0.001). Lesion-level analyses (n = 118) showed no differences when remodelling was defined by the local reference approach at baseline or follow-up.

CONCLUSION

Remodelling assessment using a global arterial reference approach, but not the commonly used, local reference site approach, correlated reasonably well with serial changes in arterial dimensions and identified arterial segments with subsequent PAV progression despite intensive statin treatment and overall atheroma regression.

Circulatory miR-133b and miR-21 as Novel Biomarkers in Early Prediction and Diagnosis of Coronary Artery Disease

While coronary artery disease (CAD) has become a major threat worldwide, the timely biomarker-based early diagnosis of CAD remains a major unmet clinical challenge. We aimed towards assessing the level of circulatory microRNAs as candidates of novel biomarkers in patients with CAD. A total of 147 subjects were recruited which includes 78 subjects with angiographically proven CAD, 15 pre-atherosclerotic normal coronary artery (NCA) subjects and 54 healthy individuals. Quantitative real-time PCR assays were performed. MiR-133b was downregulated by 4.6 fold (p < 0.0001) whereas miR-21 was upregulated by ~2 fold (p < 0.0001) in plasma samples of CAD patients. Importantly, both the miRNAs showed association with disease severity as miR-133b was downregulated by 8.45 fold in acute coronary syndrome (ACS), 3.38 fold in Stable angina (SA) and 2.08 fold in NCA. MiR-21 was upregulated by 2.46 fold in ACS, 1.90 fold in SA and 1.12 fold in NCA. Moreover, miR-133b could significantly differentiate subjects with ST-elevation myocardial infarction (STEMI) from Non-STEMI. Area under the curve (AUC) for miR-133b was 0.80 with >75.6% sensitivity and specificity, AUC for miR-21 was 0.79 with >69.4% sensitivity and specificity. Our results suggest that miR-133b and miR-21 could be possible candidates of novel biomarkers in early prediction of CAD.

Clinical indicators and coronary angiographic features of expansive arterial remodelling in patients with abdominal aortic aneurysms

The co-existence of expansive arterial remodelling in both coronary arteries (CAs) and the abdominal aorta has already been reported, although the clinical indicators and quantitative analysis have not been well studied. We therefore aimed to clarify the clinical and anatomical characteristics of patients with abdominal aortic aneurysms (AAAs). 123 AAA patients who underwent coronary angiography were compared to 123 control patients selected by propensity score matching. CA diameters of all 3 vessels were measured by quantitative coronary angiographic analysis. Coronary artery ectasia (CAE) was defined as local or generalized aneurysmal change of the CAs. Excessive expansive CA remodelling was defined as the maximal diameter of the right or left circumflex artery in the upper 75th percentile (>4.8 mm). Multivariable logistic regression analyses were used to determine predictors of CAE and excessive expansive CA remodelling. The prevalences of CAE and excessive expansive CA remodelling were significantly higher in the AAA group than in the non-AAA group (28% vs. 8% and 31% vs. 19%; both p<0.05). On multivariable analysis, the presence of AAA (odds ratio (OR), 4.56; 95% confidence intervals (95%CI) 2.18-10.4) and body mass index (BMI) (OR, 1.11; 95%CI 1.03-1.21) were independently associated with CAE, and higher high-sensitivity C-reactive protein (OR, 2.19; 95%CI 1.08-4.52) and BMI (OR, 1.11; 95%CI 1.02-1.21) were independently associated with excessive expansive CA remodelling. In conclusions, this study showed a higher prevalence of ectatic CA disease in AAA patients and suggests that higher inflammation and obesity are associated with expansive arterial remodelling in coronary arteries.

In-vivo MRI Reveals Changes to Intracerebral Vasculature Caliber in HIV Infection

Objective: To characterize cerebral arterial remodeling in HIV-infected (HIV+) individuals in-vivo, and to study its clinical and immunological associations.

Methods: T2^*-weighted magnetic resonance imagining sequences was used to determine cross-sectional area (vascular caliber) of the anterior (A1 segment) and middle (M1 segment) cerebral arteries in HIV- (control) and HIV+ subjects on antiretroviral therapy. Correlations of A1 caliber with clinical, demographic parameters, and immunological markers in cerebrospinal fluid (CSF) were determined using multivariable analyses.

Results: A1 and M1 calibers from 22 HIV- control subjects (age: median 48.5 years, range 22-60 years, 55% male) and 61 HIV+ subjects (age: median 53 years, range 25–60 years, 67% male) were studied. ANCOVA, adjusting for ethnicity and sex (age was not correlated with M1 or A1 caliber in either group), revealed that HIV+ subjects had larger caliber in the A1 segment than HIV- subjects (4.95 ± 0.14 mm², and 4.47 ± 0.21 mm² respectively, p = 0.048), but caliber of the M1 segment did not differ among the groups (7.21 ± 0.14 mm² and 7.09 ± 0.23 mm² respectively, p = 0.65). In the HIV+ cohort, longer disease duration and higher current CD4 T-cell count were associated with reduced A1 caliber (r =−0.42 and −0.33 respectively, p < 0.05). In addition, increase in cardiovascular disease risk (CVD risk) was associated with a decrease in A1 caliber in the HIV group (r = −0.35, p < 0.05).

Conclusions: This cross-sectional study reveals an increase in A1 caliber in the HIV+ cohort, compared to control subjects, which is especially prominent in early phase of the disease. This increase in caliber may be associated with acute pathological processes in HIV during the initial stages of infection resulting in loss of compliance or thinning of the arterial wall. At later stages, such changes may be confounded by arteriosclerotic changes that are common in later stages of HIV infection. This study suggests there is extensive vessel remodeling in various stages of infection. Long-term longitudinal follow-up of this cohort is planned to further verify this hypothesis and to better understand this MRI marker of intracranial vascular caliber.

Intravascular assessment of coronary arteries in patients with cyanotic congenital heart disease

AIMS

Patients with cyanotic congenital heart disease (CCHD) have been suggested to develop less atherosclerosis than the general population. This study aimed to evaluate the extent of coronary atherosclerosis in patients with CCHD using intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS).

METHODS AND RESULTS

Fifteen patients with CCHD (women, 9; median age, 53 years) and 14 acyanotic controls (women, 6; median age, 53 years) were examined with IVUS-NIRS of the right coronary artery (RCA). The patients with CCHD presented with a larger RCA diameter than the controls (external elastic membrane diameter, 6.1 [4.8-6.7] vs. 4.7 [4.1-5.1] mm, respectively; p=0.01). No difference in area stenosis was found between the patients and the controls (15.8% [12.3-19.7] vs. 15.2% [9.5-18.8]; p=0.87). The presence of lipid by NIRS was noted in 43% of patients with CCHD and in 92% of the controls; however, no differences in total or max 4 mm lipid core burden index (LCBI) or in plasma lipid profile were found.

CONCLUSIONS

Patients with CCHD presented with larger coronary arteries than acyanotic controls. No difference in the degree of area stenosis in the coronary arteries was found between the cyanotic and acyanotic patients; however, a lower proportion of patients with CCHD showed a positive LCBI.

High shear stress on the coronary arterial wall is related to computed tomography-derived high-risk plaque: a three-dimensional computed tomography and color-coded tissue-characterizing intravascular ultrasonography study

Low wall shear stress (WSS) is associated with plaque formation. However, the relationship between WSS and coronary plaque vulnerability remains unclear. Therefore, this study aimed to clarify the in vivo relationship between luminal WSS derived from three-dimensional (3D) computed tomography (CT) and plaque vulnerability within the coronary artery. Forty-three consecutive patients with ischemic heart disease and coronary stenotic lesions were enrolled and underwent coronary angiography and color-coded intravascular ultrasonography (iMap™) followed by multi-slice coronary CT angiography. CT-derived high-risk plaque was defined by specific CT characteristics, including low CT intensity (< 30 HU) and positive remodeling. The Student's t test, Mann-Whitney U test, χ² test, repeated measures analysis of variance, and logistic and multiple regression were used for statistical analyses. CT-derived high-risk plaque (n = 15) had higher values of maximum and average shear stress than CT-derived stable plaque (474 ± 453 vs. 158 ± 138 Pa, p = 0.018; 4.2 ± 3.1 vs. 1.6 ± 1.2 Pa, p = 0.007, respectively). Compared with patients with CT-derived stable plaque, those with CT-derived high-risk plaque had a higher prevalence of necrotic and lipidic characteristics (44 ± 13 vs. 31 ± 11%, p = 0.001) based on iMap™. Multivariate logistic regression analysis showed that the average WSS and necrotic plus lipidic content were independent determinants of CT-derived high-risk plaque (average WSS: odds ratio 2.996, p = 0.014; necrotic plus lipidic content: odds ratio 1.306, p = 0.036). Our findings suggested that CT-derived high-risk plaque may coexist with high shear stress on the plaque surface.

Dual-Element Intravascular Ultrasound Transducer for Tissue Harmonic Imaging and Frequency Compounding: Development and Imaging Performance Assessment

OBJECTIVE

For accurate diagnosis of atherosclerosis, the high spatial and contrast resolutions of intravascular ultrasound (IVUS) images are a key requirement. Increasing the center frequency of IVUS is a simple solution to meet this requirement. However, this leads to a reduction in imaging depth due to the frequency-dependent attenuation of ultrasound. Here, we report a recently developed dual-element IVUS transducer for tissue harmonic imaging (THI) and frequency compounding to increase the spatial and contrast resolutions of IVUS images, while maintaining the imaging depth to assess the overall morphological change of blood vessels.

METHODS

One 35-MHz element is used for producing general IVUS images and the other 70-MHz element is for receiving the second harmonic signals induced by the 35-MHz ultrasound. The fundamental and second harmonic signals can also be used for frequency compound imaging to further improve contrast resolution. The spatial and contrast resolutions achieved by the developed transducer were evaluated through wire and tissue-mimicking phantom imaging tests. Additionally, the images of a stent deployed in a tissue-mimicking phantom and an excised pig artery were acquired to assess clinical usefulness of the transducer.

RESULTS

The results demonstrated that the developed IVUS transducer enables us to simultaneously examine the overall morphological change of blood vessels by the 35-MHz ultrasound images and the near vessel layers such as the intima, the media, and the adventitia by either THI or compound images with high spatial and contrast resolutions. In addition, the developed transducer facilitates the simultaneous acquisition of 35- and 70-MHz fundamental images when needed.

CONCLUSION

The developed dual-element IVUS transducer makes it possible to fully realize the potential benefits of IVUS in the diagnosis of atherosclerosis.

Primary percutaneous coronary intervention in ST-elevation myocardial infarction with an ectatic infarct-related artery

OBJECTIVE

The aim of this study was to describe the procedural characteristics, myocardial perfusion, and long-term outcomes in ST-elevation myocardial infarction patients with an ectatic infarct-related artery (IRA).

PATIENTS AND METHODS

The retrospective analysis included 1270 consecutive ST-elevation myocardial infarction patients treated by primary percutaneous coronary intervention who were categorized according to the coronary anatomy of the IRA as follows: ectatic group (n=91) and control group (n=1179).

RESULTS

Compared with the control group, patients in the ectatic group experienced lower Thombolysis in myocardial infarction grade 3 flow rate after percutaneous coronary intervention (64.8 vs. 88.2%: ectatic group vs. nonectatic group, P<0.001) and more frequent distal embolization (44.4 vs. 11.1%, P<0.001). ECG ST resolution was significantly lower in the ectatic group (P<0.001). Paradoxically, the left ventricular ejection fraction values at discharge were significantly higher in the ectatic group (P=0.032) and the infarct size assessed within 6-12 months after discharge tended to be smaller (P=0.06). The 30-day mortality rate was not significantly different between the two groups (3.3 vs. 5.0%, P=0.378) as well as Kaplan-Meier analysis for long-term overall survival in both groups (P=0.8).

CONCLUSION

Patients with ectatic IRA were characterized by discrepancies between high angiographic thrombus burden in a larger vessel and impact on left ventricular function that may influence their long-term survival.

Imaging Characteristics of Mismatch Lesions: An Angiographic and Intravascular Ultrasound Analysis of 1369 Coronary Lesions

OBJECTIVES

To evaluate the angiographic and intravascular ultrasound (IVUS) characteristics of coronary mismatch lesions.

BACKGROUND

Better understanding about the characteristics of mismatch lesions may help to achieve more accurate lesion assessment and, thereby, to improve the outcomes of percutaneous coronary intervention (PCI).

METHODS

Angiographic and IVUS data from 1369 lesions were analyzed. Mismatch lesion was defined as the difference between proximal and distal reference lumen diameters of ≥1.0 mm or ≥30% of the distal reference lumen diameter.

RESULTS

The incidence of mismatch lesions was 20.1% (275/1369). Compared to nonmismatch group, mismatch group had longer lesions (21.3 [6.4] mm vs 18.4 [6.4] mm, P < .001) with smaller minimum lumen diameter (0.87 [0.29] mm vs 1.10 [0.31] mm, P < .001) and more severe diameter stenosis (78.8% [9.2%] vs 66.3% [10.3%], P < .001). On IVUS, mismatch group had larger lumen area (18.7 [5.0] vs 15.8 [5.1] mm², P < .001) but lower plaque burden at the proximal reference segment (41.0% [9.2%] vs 45.7% [9.9%], P < .001) and smaller lumen area (4.83 [1.89] vs 7.36 [2.89] mm, P < .001) but higher plaque burden at the distal reference segment (42.9% [10.4%] vs 41.4% [10.1%], P = .023). Multivariable logistic regression analysis showed that mismatch lesions were frequently accompanied by diffuse lesions (odds ratio [OR] = 2.50; 95% confidence interval [CI]: 1.83-3.40; P < .001), bifurcation lesions (OR = 5.83; 95% CI: 4.40-7.74; P < .001), and lesions with a low TIMI flow grade (OR = 1.70; 95% CI: 1.08-2.67; P = .022) or severe diameter stenosis (OR = 3.05; 95% CI: 2.10-4.43; P < .001).

CONCLUSIONS

Mismatch lesions are quite common and characterized by greater lesion complexity compared with nonmismatch lesions. Further studies may be necessary to address the impact of this lesion type on the outcome of PCI.

Gender-associated dimensional differences among normal to non-flow limiting coronary artery dimensions

Aim and objectives

To study gender-specific differences in coronary artery diameters among subjects with normal to non-flow limiting disease (NFLD) coronary arteries (up to 0 - 20% of stenosis) and to assess the possible association of body-mass index (BMI) with coronary dimensions, among the west coastal population of Karnataka and Kerala.

Materials and Methods

A prospective cohort study was conducted for a period of one year. Two thousand angiograms samples were collected and assessed from two study centers (one from each state), after obtaining the ethical clearance. Patients with past history of myocardial infarction and those with recanalized normal looking coronary arteries and those who had diabetes for more than five years were excluded. Ten segments of coronary arteries- left main coronary artery, ostial and proximal segments of left anterior descending artery and its first diagonal branch, ostial and proximal segments of left circumflex coronary artery and its obtuse marginal branch, ramus intermedius and the ostial and proximal segments of the right coronary artery- were included in diameter measurement. BMI values of the patients were calculated.

Results

Out of 2000 patients included in the study, 454 (22.7%; mean age 53.4 ± 14.2 years) had normal to NFLD coronaries of which 253 (55.7%) were males and 201 (44.3%) were females. As compared to women, men had larger diameters of coronary arteries for eight segments, except the obtuse marginal branch and the proximal right coronary artery. A weak, yet statistically significant, negative correlation existed between BMI and coronary artery diameters in total cohort, indicating that an increase in BMI was associated with a decrease in artery diameters. No such association was seen when men and women were assessed separately.

Conclusions

The present study indicates that men have higher caliber for coronary arteries compared to women. The study also indicates that when BMI increases there is a relative decrease in the coronary artery diameter.

Extreme negative remodeling of septal left anterior descending branch masquerading as a bifurcation lesion

We report a case of severe negative remodelling at the ostium of septal LAD artery. We deferred stenting to avoid the risk of rupture of the vessel and stent fracture.

The effects of stenting on coronary endothelium from a molecular biological view: Time for improvement?

Coronary artery stenting following balloon angioplasty represents the gold standard in revascularization of coronary artery stenoses. However, stent deployment as well as percutaneous transluminal coronary angioplasty (PTCA) alone causes severe injury of vascular endothelium. The damaged endothelium is intrinsically repaired by locally derived endothelial cells and by circulating endothelial progenitor cells from the blood, leading to re‐population of the denuded regions within several weeks to months. However, the process of re‐endothelialization is often incomplete or dysfunctional, promoting in‐stent thrombosis and restenosis. The molecular and biomechanical mechanisms that influence the process of re‐endothelialization in stented segments are incompletely understood. Once the endothelium is restored, endothelial function might still be impaired. Several strategies have been followed to improve endothelial function after coronary stenting. In this review, the effects of stenting on coronary endothelium are outlined and current and future strategies to improve endothelial function after stent deployment are discussed.

Extent of coronary atherosclerosis and arterial remodelling in women: the NHLBI-sponsored Women's Ischemia Syndrome Evaluation

Background

Information regarding the pathogenesis of ischemic heart disease (IHD) in women is limited. Sex-specific responses to atherosclerosis and coronary arterial remodelling in women versus men have been hypothesized, but limited study exists.

Methods

Case-matched study of 174 women with suspected ischemia referred for coronary angiography: 87 with non-obstructive coronary artery disease (CAD) (no luminal diameter stenosis >20% in any coronary artery) and 87 age and ethnicity matched women with obstructive CAD. Groups were compared with regard to atheroma burden and coronary arterial remodelling assessed by coronary artery intravascular ultrasound (IVUS).

Results

IVUS revealed more extensive atheroma with obstructive CAD vs. those without obstructive CAD, with greater percent atheroma volume (PAV) (36.1%±9.8% vs. 25.4%±9.1%, P<0.0001), total atheroma volume (TAV) (140.8±58.7 vs. 98.8±46.9 mm³, P<0.0001) and percentage of images containing plaque (70.0%±30.5% vs. 35.7%±32.6%, P<0.0001). Adjusting for risk factors, PAV (35%±1% vs. 28%±1%, P=0.0008), TAV (131±7 vs. 115±7 mm³, P=0.110) and percentage of images containing plaque (66%±4% vs. 45%±5%, P=0.0008) remained greater with obstructive CAD. Obstructive CAD was associated with smaller lumen volumes (251.9±92.8 vs. 289.7±91.8 mm³, P=0.005), but surprisingly, the external elastic membrane (EEM) volume was very similar comparing the groups (392.7±128.1 vs. 388.6±113.7 mm³, P=0.910).

Conclusions

Our findings suggest that women referred to angiography for suspected ischemia, have differing patterns of coronary arterial response to injury with regard to accumulation of atherosclerosis and compensatory remodelling related to the presence and absence of obstructive CAD. Preservation and cultivation of compensatory arterial remodelling may be a novel CAD therapeutic target.

Evaluation of Carotid Wall Thickness by using Computed Tomography and Semiautomated Ultrasonographic Software

Purpose

The increased thickness of the carotid artery is associated with the development of coronary and cerebrovascular events. In this study our purpose was to evaluate the carotid artery wall thickness (CAWT) by using multidetector-row computed tomography angiography (MDCTA) and the intima media thickness (IMT) by using semiautomated ultrasonography (SA-US) to evaluate the agreement between the two methods.

Methods

This is a retrospective study, and the institutional review board approval was obtained. Twenty-one patients (age range, 59–81 years) were analyzed with the use of a 16-detector row CT and a sonographic scanner. In total, 14 subjects had shown cerebral ischemic symptoms. The IMT was quantified by the use of specific semiautomated software (ImgTracer™, Global Biomedical Technologies, Roseville, CA) by four expert observers, and the CAWT was measured by use of the MDCTA. Data were compared with the Wilcoxon test for paired samples. Bland–Altman statistics was used to measure the agreement between MDCTA and SA-US. A p value < 0.05 was considered significant.

Results

Forty-two carotids were analyzed, and the CAWT ranged from 0.64 to 2.99 mm, with a mean value of 1.438 mm. By analyzing the Bland–Altman plots, we observed a good agreement between SA-US and correlation coefficient r were 0.9250 (95% confidence interval [CI] 0.864–0.959; p < 0.0001), 0.9265 (95% CI 0.866–0.961; p < 0.0001), 0.9466 (95% CI 0.902–0.971; p < 0.0001), and 0.8621 (95% CI: 0.756–0.924; p < 0.0001) for observer 1, observer 2, observer 3 and observer 4 respectively.

Conclusions

Data of this preliminary study by using SA-US and MDCTA demonstrated a good agreement between in the measurement of CAWT and IMT.

Assessment of superficial coronary vessel wall deformation and stress: validation of in silico models and human coronary arteries in vivo

Cyclic biomechanical stress at the lumen-intima interface plays a crucial role in the rupture of coronary plaque. We performed a comprehensive assessment of a novel angiography-based method for four-dimensional (4D) dynamic assessment of superficial wall stress (SWS) and deformation with a total of 32 analyses in virtual stenosis models with equal lumen dimensions and 16 analyses in human coronary arteries in vivo. The in silico model analyses demonstrated that the SWS, derived by the proposed global displacement method without knowledge of plaque components or blood pressure, was comparable with the result calculated by traditional finite element method. Cardiac contraction-induced vessel deformation increased SWS. Softer plaque and positive arterial remodeling, associated with a greater plaque burden, showed more variation in mean lumen diameter within the cardiac cycle and resulted in higher SWS. In vivo patient analyses confirmed the accuracy of computed superficial wall deformation. The centerlines predicted by our method at random selected time instant matched well with the actual one in angiograms by Procrustes analysis (scaling: 0.995 ± 0.018; dissimilarity: 0.007 ± 0.014). Over 50% of the maximum SWS occurred at proximal plaque shoulders. This novel 4D approach could be successfully to predict superficial wall deformation of coronary artery in vivo. The dynamic SWS might be more realistic to evaluate the risk of plaque rupture.

Analysis of Cardiovascular Tissue Components for the Diagnosis of Coronary Vulnerable Plaque from Intravascular Ultrasound Images

The purpose of this study was to characterize cardiovascular tissue components and analyze the different tissue properties for predicting coronary vulnerable plaque from intravascular ultrasound (IVUS) images. For this purpose, sequential IVUS image frames were obtained from human coronary arteries using 20 MHz catheters. The plaque regions between the intima and media-adventitial borders were manually segmented in all IVUS images. Tissue components of the plaque regions were classified into having fibrous tissue (FT), fibrofatty tissue (FFT), necrotic core (NC), or dense calcium (DC). The media area and lumen diameter were also estimated simultaneously. In addition, the external elastic membrane (EEM) was computed to predict the vulnerable plaque after the tissue characterization. The reliability of manual segmentation was validated in terms of inter- and intraobserver agreements. The quantitative results found that the FT and the media as well as the NC would be good indicators for predicting vulnerable plaques in IVUS images. In addition, the lumen was not suitable for early diagnosis of vulnerable plaque because of the low significance compared to the other vessel parameters. To predict vulnerable plaque rupture, future study should have additional experiments using various tissue components, such as the EEM, FT, NC, and media.

High-resolution vessel wall MRI for the evaluation of intracranial atherosclerotic disease

High-resolution vessel wall MRI (vwMRI) of the intracranial arteries is an emerging diagnostic imaging technique with the goal of evaluating vascular pathology. vwMRI sequences have high spatial resolution and directly image the vessel wall by suppressing blood signal. With vwMRI, it is possible to identify distinct morphologic and enhancement patterns of atherosclerosis that can provide important information about stroke etiology and recurrence risk. We present a review of vwMRI research in relation to intracranial atherosclerosis, with a focus on the relationship between ischemic stroke and atherosclerotic plaque T1 post-contrast enhancement or plaque/vessel wall morphology. The goal of this review is to provide readers with the most current understanding of the reliability, incidence, and importance of specific vwMRI findings in intracranial atherosclerosis, to guide their interpretation of vwMRI research, and help inform clinical interpretation of vwMRI. We will also provide a translational perspective on the existing vwMRI literature and insight into future vwMRI research questions and objectives. With increased use of high field strength MRI, powerful gradients, and improved pulse sequences, vwMRI will become standard-of-care in the diagnosis and prognosis of patients with cerebrovascular disease, making a firm grasp of its strengths and weakness important for neuroimagers.