Symptomatic Arteries Research Articles

Using machine learning to predict carotid artery symptoms from CT angiography: A radiomics and deep learning approach

PurposeTo assess radiomics and deep learning (DL) methods in identifying symptomatic Carotid Artery Disease (CAD) from carotid CT angiography (CTA) images. We further compare the performance of these novel methods to the conventional calcium score. MethodsCarotid CT angiography (CTA) images from symptomatic patients (ischaemic stroke/transient ischaemic attack within the last 3 months) and asymptomatic patients were analysed. Carotid arteries were classified into culprit, non-culprit and asymptomatic. The calcium score was assessed using the Agatston method. 93 radiomic features were extracted from regions-of-interest drawn on 14 consecutive CTA slices. For DL, convolutional neural networks (CNNs) with and without transfer learning were trained directly on CTA slices. Predictive performance was assessed over 5-fold cross validated AUC scores. SHAP and GRAD-CAM algorithms were used for explainability. Results132 carotid arteries were analysed (41 culprit, 41 non-culprit, and 50 asymptomatic). For asymptomatic vs symptomatic arteries, radiomics attained a mean AUC of 0.96(± 0.02), followed by DL 0.86(± 0.06) and then calcium 0.79(± 0.08). For culprit vs non-culprit arteries, radiomics achieved a mean AUC of 0.75(± 0.09), followed by DL 0.67(± 0.10) and then calcium 0.60(± 0.02). For multi-class classification, the mean AUCs were 0.95(± 0.07), 0.79(± 0.05), and 0.71(± 0.07) for radiomics, DL and calcium, respectively. Explainability revealed consistent patterns in the most important radiomic features. ConclusionsOur study highlights the potential of novel image analysis techniques in extracting quantitative information beyond calcification in the identification of CAD. Though further work is required, the transition of these novel techniques into clinical practice may eventually facilitate better stroke risk stratification.

Triglyceride-Related Parameters and Symptomatic Atherosclerotic Lesions in Patients With Ischemic Stroke.

Recently, evidence has suggested that the pathophysiology and risk factors of intracranial atherosclerosis (ICAS) differs from those of extracranial atherosclerosis (ECAS). In addition, novel parameters reflecting metabolic conditions, such as insulin resistance or atherogenic dyslipidemia, based on triglycerides (TG) and other biomarkers, have emerged. In this study, we evaluated the association between TG-related parameters and symptomatic cerebral atherosclerosis in patients with acute ischemic stroke resulting from large artery atherosclerosis (LAA). We assessed consecutive acute LAA-stroke patients between January 2010 and December 2020. Based on the radiological findings, we classified the relevant symptomatic arteries that caused the index stroke into LAA-ICAS and LAA-ECAS. As TG-related parameters, the atherogenic index of plasma (AIP) and TG-glucose (TyG) index were calculated according to the following formulas: AIP = log10 (TG Level/High-density Lipoprotein Cholesterol Level), TyG Index = Ln (TG Level × Glucose Level/2). A total of 519 patients with LAA-stroke were evaluated. In multivariable logistic regression analysis to identify predictors of LAA-ICAS, AIP was significantly associated with LAA-ICAS (adjusted odds ratio [aOR], 3.60; 95% confidence interval [CI], 1.60-8.06). TyG index also showed a statistically significant relationship with LAA-ICAS (aOR, 1.60; 95% CI, 1.11-2.32). However, TG per se did not show a statistical association with LAA-ECAS. TG-related parameters were more closely associated with stroke by ICAS than by ECAS. The metabolic conditions reflected by the AIP or TyG index, rather than hypertriglyceridemia itself, may play a greater role in determining the relevant vessel causally involved in a stroke.

Usefulness of Self-Expandable Stent for Recanalization of Intracranial Atherosclerotic Disease: Preliminary Experience with Enterprise Stent.

PurposeThe purpose of this preliminary study is to evaluate the efficacy and safety of the Enterprise stent for intracranial atherosclerotic disease (ICAD) in patients who presented with acute stroke due to vessel steno-occlusion and in patients with symptomatic disease despite optimum medical management.Materials and MethodsA retrospective data analysis was performed on 15 consecutive patients who were treated with Enterprise stenting for recanalization of symptomatic intracranial steno-occlusive arteries due to underlying ICAD. Their clinical and radiological data were reviewed to evaluate procedural results, periprocedural and postprocedural complications, and clinical outcome.ResultsEnterprise stents were deployed as a rescue method in 15 patients for recanalization of steno-occlusion. All patients achieved final modified thrombolysis in cerebral infarction (mTICI) score improvement (53.3% with a mTICI score from 0 to 2b or 3, 46.7% with a mTICI score from 1 to 3). Two postprocedural complications (1 symptomatic intracranial hemorrhage and 1 severe brain edema, 13.3%) occurred among 15 patients. Among 12 patients with acute ischemic stroke (AIS), 6 patients (50%) had improvement in their National Institute of Health Stroke Scale of more than 4 at discharge. Seven patients (58.3%) had a good functional outcome with 3-month modified Rankin Score (mRS)≤2, and mortality occurred (mRS=6) in 2 patients (16.7%). None of the 10 AIS and 3 transient ischemic attack patients experienced further ischemic events attributable to the treated steno-occlusion during the follow-up period (ranged from 4 to 36 months, median 12 months).ConclusionThis retrospective study suggests that Enterprise stenting can effectively and safely achieve recanalization in symptomatic steno-occlusive intracranial arteries.

Association of symptomatic atherosclerotic carotid arteries with plaque areas showing low densities on computed tomographic angiography

Intraplaque hemorrhage is a key feature of vulnerable carotid atherosclerotic plaque (CAP), associated with low densities (<25 Hounsfield units [HU]) on computed tomographic angiography (CTA). This study aimed to analyze CAP on routine CTA performed in patients with symptomatic and asymptomatic carotid stenosis undergoing carotid endarterectomy (CEA) by assessing HU of the CAP area showing the lowest density (CAPALD) using radiological tools available in daily clinical practice, and to compare CAPALD values between symptomatic and asymptomatic carotids. We retrospectively screened preoperative CTA scans of 206 consecutive adult patients undergoing CEA for symptomatic or asymptomatic stenosis. CAPALD values were compared between symptomatic and asymptomatic carotids. Asymptomatic carotids included arteries contralateral to the symptomatic CEA artery, and asymptomatic stenotic arteries undergoing CEA and their contralateral arteries. Carotids were excluded when there was <30% stenosis, or when CAP could not be identified or CAPALD could not be measured. In total, 95 symptomatic and 112 asymptomatic carotids (derived from 174 patients) were analyzed. In multivariate analysis, symptomatic arteries showed more severe stenosis (median 70% vs. 67%, p=0.0228) and lower CAPALD values (median 17 vs. 25 HU, p=0.049), whereas degree of stenosis and CAPALD values were not correlated (rho=-0.02, p=0.77). HU values of <25 were more frequent in symptomatic than asymptomatic carotids (68% vs. 47%, p=0.0022). On CTA, symptomatic carotids are associated with CAP areas with low densities. CTA analysis of CAP may be interesting to help identify vulnerable plaques at risk for future stroke, especially in patients lacking strict indications for CEA based on the current guidelines.

Three Different Strategies for Repair of Symptomatic or Aneurysmatic Aberrant Right Subclavian Arteries.

In this study, we aimed to present three different methods for symptomatic aberrant right subclavian artery (ARSA) surgery. We identified 11 consecutive adult patients undergoing symptomatic and/or aneurysmal ARSA repair between January 2016 and December 2020. Symptoms were dysphagia (n=8) and dyspnea + dysphagia (n=3). Six patients had aneurysm formation of the ARSA (mean diameter of 4.2 cm [range 2.8 - 6.3]). All data were analyzed retrospectively. Median age of the patients (7 females/4 males) was 55 years (range 49 - 62). The first four patients (36.4%) underwent hybrid repair using thoracic endovascular aortic repair (TEVAR) and bilateral carotid-subclavian artery bypass (CScBp). Three patients (27.2%) were treated by open ARSA resection/ligation with left mini posterolateral thoracotomy (LMPLT) and right CScBp. And the last four patients (36.4%) underwent ARSA resection/ligation with LMPLT and ascending aorta-right subclavian artery bypass with upper mini sternotomy (UMS). Two of the four patients who underwent TEVAR + bilateral CScBp had continuing dysphagia cause of persistent esophageal compression. Brachial plexus injury developed in one of three patients who underwent LMPLT + right CScBp. Pleural effusion treated with thoracentesis alone was observed in one of four patients who underwent UMS + LMPLT. Among the symptomatic and/or aneurysmal ARSA treatment approaches, surgical and hybrid methods are used. There is still no consensus on how to manage these patients. In our study, we recommend the UMS + LMPLT method, since the risk of complications with anatomical bypass is less, and we have more successful surgical results.

Intracranial dolichoectasia in patients with symptomatic intracranial atherosclerotic disease: Results from the MYRIAD study.

It is unknown whether intracranial atherosclerotic disease (ICAD), in addition to causing stenosis, also associates with abnormal arterial enlargement, a condition known as intracranial dolichoectasia (IDE). Across symptomatic ICAD patients, we aim to determine IDE prevalence and IDE impact on cerebral hemodynamics and recurrent cerebral ischemia. We analyzed 98 participants (mean age 63.8 11.9 years, 56.1% men) of the prospective observational study MYRIAD. Participants were enrolled within 21 days of an ischemic stroke or transient ischemic attack caused by moderate-to-severe ICAD. Semi-automatic vessel segmentation was used to determine diameters, length, and tortuosity-index of proximal intracranial arteries. Either ectasia (increased diameter) or dolichosis (increased length or TI) defined IDE. We assessed IDE association with new infarcts during 12-month follow-up, and IDE correlation with cerebral hemodynamics determined by quantitative MR-angiography (QMRA), MR-perfusion weighted-imaging, and transcranial Doppler breath-holding index. IDE was present in 35.7% of patients and 10.2% of symptomatic arteries. Basilar stenosis was associated with higher IDE prevalence (27.8% vs. 8.8%, p = 0.04), whereas other symptomatic arteries showed no association with IDE. Symptomatic arteries with IDE had lower hypoperfusion prevalence on MR-PWI (11.1% vs. 28.4%, p = 0.03). Increased diameter (r = 0.33, p<0.01) and tortuosity-index (r = 0.29, p = 0.01) showed positive correlation with QMRA flow rate. IDE was not associated with new infarcts during follow-up. IDE was common among symptomatic ICAD patients. IDE was not associated with stroke recurrence. Instead, increased diameter and tortuosity correlated with improved blood flow across the stenotic artery, suggesting that IDE may originate as an adaptive mechanism in ICAD.

Carotid Intraplaque Hemorrhage and Stenosis: At What Stage of Plaque Progression Does Intraplaque Hemorrhage Occur, and When is It Most Likely to Be Associated with Symptoms?

The relationship between carotid intraplaque hemorrhage and luminal stenosis severity is not well-established. We sought to determine whether intraplaque hemorrhage is related to carotid stenosis and at what degree of stenosis intraplaque hemorrhage most likely contributes to ischemic symptoms. Consecutive patients who underwent MR carotid plaque imaging with MPRAGE sequences to identify intraplaque hemorrhage were retrospectively reviewed. Degrees of stenoses were categorized as minimal (<30%), moderate (30%-69%), and severe (>70%). Arteries were categorized into 2 groups: symptomatic (ipsilateral to a cerebral ischemic event) and asymptomatic (from a patient without an ischemic event). Multiple regression analyses were used to determine independent associations between the degree of stenosis and intraplaque hemorrhage and the presence of intraplaque hemorrhage with symptoms among categories of stenosis. We included 449 patients with 449 carotid arteries: Two hundred twenty-five (50.1%) were symptomatic, and 224 (49.9%) were asymptomatic. An increasing degree of stenosis was independently associated with the presence of intraplaque hemorrhage (OR = 1.02; 95% confidence interval, 1.01-1.03). Intraplaque hemorrhage was independently associated with ischemic events in arteries with <30% stenosis (OR = 5.68; 95% CI, 1.49-21.69). No such association was observed in arteries with >30% stenosis. Of symptomatic arteries with minimal stenosis, 8.7% had intraplaque hemorrhage versus 1.7% of asymptomatic arteries (P = .02). No differences in intraplaque hemorrhage prevalence were found between symptomatic and asymptomatic groups with moderate (P = .18) and severe stenoses (P = .99). The presence of intraplaque hemorrhage on high-resolution plaque imaging is likely most useful in identifying symptomatic plaques in cases of minimal stenosis.

Comparison of Carotid Plaque Characteristics Between Men and Women Using Magnetic Resonance Vessel Wall Imaging: A Chinese Atherosclerosis Risk Evaluation Study.

Carotid vulnerable plaque is a major cause of stroke and differs between men and women. Few studies have investigated the differences in carotid plaque features between sexes in a Chinese population. To compare carotid atherosclerotic plaque features between men and women in a Chinese population using magnetic resonance imaging. Cross-sectional. A total of 567 patients (mean age: 61.5 ± 10.1 years; 404 men) who had recent stroke or transient ischemia attack and atherosclerotic plaque in at least one carotid artery. A 3.0 T. T1- and T2-weighted turbo spin echo, three-dimensional time-of-flight (TOF) fast field echo and magnetization-prepared rapid acquisition gradient echo sequences. Plaque characteristics including lumen area (LA), wall area (WA), total vessel area (TVA), mean wall thickness (MWT), and mean normalized wall index (NWI); presence of calcification, lipid-rich necrotic core (LRNC), intraplaque hemorrhage (IPH), and fibrous cap rupture (FCR); and percent composition area (%area) were evaluated and compared between men and women. Independent-sample t test, Mann-Whitney U test, chi-square test, and multiple linear and logistic regressions. In symptomatic arteries, men had significantly greater LA (46.2 ± 15.6 mm2 vs. 40.7 ± 12.9 mm2 , P < 0.05), WA (33.9 ± 11.5 mm2 vs. 26.3 ± 7.5 mm2 , P < 0.05), and TVA (80.1 ± 20.4 mm2 vs. 67.0 ± 18.0 mm2 , P < 0.05); higher MWT (1.2 ± 0.4 mm vs. 1.0 ± 0.2 mm, P < 0.05); and higher prevalence of LRNC (72.3% vs. 46.0%, P < 0.05) and IPH (18.6% vs. 4.9%, P < 0.05) compared with women. In asymptomatic arteries, men had significantly greater LA (48.3 ± 16.9 mm2 vs. 42.1 ± 12.6 mm2 , P < 0.05), WA (32.9 ± 11.0 mm2 vs. 25.8 ± 6.1 mm2 , P < 0.05), and TVA (81.2 ± 22.1 mm2 vs. 67.9 ± 16.5 mm2 , P < 0.05); higher MWT (1.2 ± 0.3 mm vs. 1.0 ± 0.2 mm, P < 0.05); higher prevalence of LRNC (67.8% vs. 42.9%, P < 0.05), IPH (14.9% vs. 1.2%, P < 0.05), and FCR (6.4% vs. 1.2%, P < 0.05); and higher %LRNC area (24.8 ± 17.2% vs. 17.8 ± 14.1%, P < 0.05) compared with women. Men have similar plaque burden but more vulnerable atherosclerotic plaques compared with women in both symptomatic and asymptomatic carotid arteries in a Chinese population. 4 TECHNICAL EFFICACY: Stage 3.

Bilaterally Asymmetric Associations Between Extracranial Carotid Artery Atherosclerosis and Ipsilateral Middle Cerebral Artery Stenosis in Symptomatic Patients: A CARE-II Study.

To determine the bilaterally asymmetrical associations between extracranial carotid artery atherosclerosis and ipsilateral middle cerebral artery (MCA) stenosis in symptomatic patients using magnetic resonance vessel wall imaging. Approach and Results: Patients with symptomatic carotid artery atherosclerosis were recruited from the Chinese Atherosclerosis Risk Evaluation, a multicenter study. All subjects underwent intracranial magnetic resonance angiography and extracranial carotid artery magnetic resonance imaging. Severe stenosis (stenosis ≥50%) of MCA, carotid moderate-to-severe stenosis (stenosis ≥50%), plaque compositions, and high-risk plaque on symptomatic side were evaluated in all subjects. Associations between ipsilateral MCA stenosis and extracranial carotid plaque features were evaluated. A total of 363 patients (mean age: 61.2±10.4 years old; 254 males) were included. In the left symptomatic cerebrovascular group (n=186), carotid moderate-to-severe stenosis (odds ratio [OR], 3.00 [95% CI, 1.03-8.79]; P=0.045), intraplaque hemorrhage (OR, 3.68 [95% CI, 1.21-11.19]; P=0.021), fibrous cap rupture (OR, 5.70 [95% CI, 1.60-20.31]; P=0.007), and high-risk plaque (OR, 2.95 [95% CI, 1.19-7.35]; P=0.020) were significantly associated with ipsilateral severe MCA stenosis, after adjusting for confounding factors. In the right symptomatic cerebrovascular group (n=177), severe MCA stenosis was significantly associated with ipsilateral carotid moderate-to-severe stenosis (OR, 3.98 [95% CI, 1.54-10.32]; P=0.004) but not with other extracranial carotid plaque features (all P>0.05), after adjusting for confounding factors. In the symptomatic arteries, vulnerable plaque features are independently associated with ipsilateral severe MCA stenosis on the left side, but this association is not found on the right side, indicating the associations of atherosclerotic disease between intracranial and extracranial carotid arteries are asymmetrical.

Correlation of MRI-detected vulnerable carotid plaques with clinical presentation: a systematic review and meta-analysis.

To determine the association between magnetic resonance imaging (MRI)-detected vulnerable Carotid Plaques and clinical presentation related to ipsilateral carotid artery territory. We searched three databases including Ovid MEDLINE, Ovid EMBASE, and Scopus from 2000 to 2018 for studies that evaluated vulnerable carotid plaques by MRI defined as intraplaque hemorrhage (IPH), lipid-rich necrotic core (LRNC), or thinning/rupture of the fibrous cap (TRFC). Data on study characteristics, clinical presentation, and MRI findings were extracted. Publication bias, methodologic quality, and study heterogeneity were assessed. Random-effects meta-analysis model was used to estimate incidence rate ratio (IRR) and 95% confidence intervals (CI) of MRI-detected vulnerable carotid plaque between symptomatic and asymptomatic arteries. Of 2855 studies, 33 studies containing 6210 participants with 8401 assessed arteries were included. Overall, the risk of bias was moderate in 13, and low in 20 studies. The prevalence of MRI-positive IPH, TRFC, and LRNC were higher in symptomatic groups compared with the asymptomatic groups. In 11 studies that compared vulnerable carotid plaques between symptomatic and asymptomatic groups, symptomatic presentation was correlated with increased risk of IPH (IRR=1.57; 95% CI: 1.24-1.99), TRFC (IRR=2.26; 95% CI: 1.83 to 3.76), and LRNC (IRR=1.95; 95% CI: 1.28 to 2.97), respectively. The presence of MRI-positive vulnerable carotid plaques including IPH, LRNC, and TRFC is positively associated with symptomatic clinical presentation. Therefore, carotid plaque MRI might be a useful risk stratification tool in determining the risk of ischemic stroke.

Symptomatic or aneurysmal aberrant subclavian arteries: results of surgical and hybrid repair.

Indications and techniques of repair for symptomatic or aneurysmal aberrant subclavian arteries (ASA) are controversial. This study analyses presentation, treatment and outcome of patients with symptomatic and/or aneurysmal ASA. Retrospective analysis of consecutive adult patients undergoing symptomatic and/or aneurysmal ASA repair between January 2000 and June 2016. Of 12 patients (4 females) with a median age of 66 years (range 24-75), 10 had right ASA and 2 had left ASA originating from a right aortic arch. Six patients (50%) had Kommerell's diverticulum and 6 patients had aneurysmal dilatation of the ASA itself. Six patients presented with symptoms (dysphagia n = 4, chest pain n = 1, recurrent aspiration n = 1). Nine patients (75%) were treated by open ASA resection/ligation with or without aortic repair. Three patients (25%) underwent hybrid repair using thoracic endovascular aortic repair to exclude the aberrant artery. ASA revascularization was achieved by subclavian-carotid transposition (n = 7), carotid-subclavian bypass (n = 1), aorto-subclavian bypass (n = 3) or reimplantation after aortic graft replacement (n = 1). Thirty-day mortality was 8% (n = 1). The median follow-up duration was 44 months (range 24-151). Symptoms were relieved in 4 and persisted partially in 1, while symptom relief remained unknown in 1 patient who died during follow-up. Imaging after a median of 34 months (range 2-134) after the operation showed patent ASA revascularization in all patients and no endoleaks in the hybrid group. Surgical and hybrid repair allows satisfying results in patients with symptomatic and/or aneurysmal ASA. The optimal procedure has to be defined on an individual patient basis. Further studies, preferably with a multicentre approach, are required to answer more specific questions on the management of these patients and especially to assess long-term results following hybrid repair.

The Use of the Agatston Calcium Score in Predicting Carotid Plaque Vulnerability

The use of the Agatston calcium scoring method has been described extensively in the coronary circulation, but to date, it has not been investigated in the extracranial carotid domain. We sought to evaluate this calcium scoring method in its ability to predict carotid plaque vulnerability. We retrospectively reviewed all computed tomography angiogram studies of the carotid arteries performed between March 2012 and March 2017 at a single institution. We identified 68 consecutive patients with 99 internal carotid arteries who met criteria for review. Total calcium was quantified by the Agatston scoring method using the OsiriX software. Stenosis severity was determined using North American Symptomatic Carotid Endarterectomy Trial criteria. The relation between Agatston score and degree of stenosis was evaluated using the Spearman's Rho coefficient (R). Of 99 internal carotid arteries, 71 were asymptomatic and 28 were symptomatic. Baseline characteristics were comparable, with no significant difference in patient characteristics. There were significant differences in mean Agatston scores for asymptomatic versus symptomatic arteries (121.95±70.27 vs. 34.83±47.77, P=0.0098, 50%-69% stenosis; 151.07±88.30 vs. 71.59±77.27, P=0.0006, 70%-99% stenosis). In both asymptomatic and symptomatic groups, Agatston calcium score increased as severity of stenosis increased. Higher Agatston score is protective against symptoms ipsilateral to the carotid lesion. Agatston calcium score may predict carotid plaque vulnerability, with higher scores associated with lower likelihood of developing symptoms ipsilateral to the carotid lesion. This score may be useful in predicting clinical behavior of carotid plaques.

Abstract WMP19: Stroke Risk in the Territory of Symptomatic Intracranial Arteries

Introduction: Recent advances in vessel wall MRI (VWMRI) have allowed characterization of intracranial atherosclerotic disease (ICAD), and some imaging characteristics, such as plaque enhancement, are associated with downstream stroke. We tested whether these features were also associated with recurrent cerebral infarction in stroke patients. Methods: 79 stroke patients with clinically established ICAD underwent VWMRI . Plaque number and features (enhancement, stenosis, eccentricity) were recorded. The cerebral infarcts were determined using DWI, and their responsible lesions (culprit) were identified based on previous established criteria. Patients were followed-up by routine clinical visits. Clinically-apparent strokes were reported and cerebral infarcts were characterized by a brain MRI acquired soon after event. Associations of imaging features and new infarcts were analyzed with adjustment for vascular risk factors. Results: Of the 79 patients (mean age 56y., 62% male, 56% whites), 13 had new infarcts (median follow-up, 16 months [IQR, 9-22 months] ). Among these 13 patients, 19 new brain infarcts were identified, and 16 were in the same vascular territories corresponding to the culprit plaque at baseline. Culprit plaques and plaque enhancement were strongly associated in univariate models with new infarcts, and in adjusted models, culprit plaques remained significant (OR 3.67, 95% CI 1.20-11.23) but plaque enhancement did not (OR 1.72, 95% CI 0.97-3.13) (Table). Plaque enhancement was associated with culprit plaques (OR 3.06, 95% CI 1.66-5.63). Conclusions: Culprit lesions were strongly associated with recurrent cerebral infarction in stroke patients, indicating increased risk for stroke in symptomatic arterial territories, likely caused by recurrent plaque rupture. Although plaque enhancement was not associated with new infarcts, its strong association with culprit lesions highlights its potential importance in future studies.

Angioplasty, Stenting and Other Potential Treatments of Atherosclerotic Stenosis of the Intracranial Arteries: Past, Present and Future.

Although there is an intuitive appeal to treat symptomatic stenotic intracranial arteries with endovascular therapies such as angioplasty and stenting, current data from randomized trials show intensive medical therapy is far superior for preventing stroke. This is in large part due to the high risk of peri-procedural stroke from angioplasty and stenting. If angioplasty and stenting is to emerge as a proven treatment for intracranial stenosis, endovascular techniques will need to become much safer, identification of patients with intracranial stenosis who are at particularly high risk of stroke despite intensive medical therapy will need to be targeted, and well-designed randomized trials will be necessary to show endovascular therapy is superior to medical therapy in these high-risk patients.

Prevalence and distribution of calcified nodules in carotid arteries in correlation with clinical symptoms.

Calcified nodules ("CN") are responsible for up to 5% of coronary-infarcts and, therefore, classified as minor criteria of "vulnerable" atherosclerotic plaque. We sought to evaluate prevalence and distribution of CN in carotid arteries in correlation with clinical symptoms. 178 consecutive patients with unilateral ischemic stroke and carotid plaques ≥2mm by duplex ultrasound underwent a carotid-black-blood-3T-MRI with fat-saturated pre- and post-contrast T1w-, PDw-, T2w- and TOF images using dedicated surface-coils. CN were defined as distinct calcification with an irregular, protruding, and convex luminal surface. Prevalence of CN was determined in common carotid artery ("CCA") and internal carotid artery ("ICA") in consensus by two reviewers blinded to clinical information. Thirty seven CN in 28 arteries of 26 patients were identified. Prevalence of CN in CCA compared to ICA was slightly higher (59 vs. 41%), but nearly similar in 66 arteries with ≥30% compared to 290 arteries with <30% stenosis (9.1 vs. 7.6%) and in the artery ipsilateral versus contralateral to stroke (7.9 vs. 7.9%; P values n.s.). Prevalence of CN was significantly higher in 40 symptomatic arteries with ≥30% stenosis compared to asymptomatic 26 arteries (15.6 vs. 0%; P=0.04). There was a significantly higher prevalence of hypercholesterolemia and hypertension in patients with CN (57.7 vs. 36.0 and 88.5 vs. 66.7%; P values <0.05). CN were found in 7.9% of arteries with carotid-plaques ≥2mm by duplex-ultrasound; prevalence was significantly higher in symptomatic arteries with ≥30% stenosis compared to asymptomatic with <30% stenosis, suggesting that CN play a role in pathogenesis of ischemic stroke in a small subset of patients.

Abstract TMP29: Non-invasive Identification of Culprit Carotid Atheroma Using Sodium Fluoride-positron Emission Tomography

Introduction: Microcalcification is a histopathological feature of atheroma at risk of rupture; so-called “vulnerable plaques.” Positron emission tomography (PET) using 18 F-sodium fluoride (NaF) has been used to detect microcalcification in ex vivo histology, though its use in vivo has been limited. We investigated the utility of NaF-PET to identify culprit carotid artery atheroma non-invasively in vivo in the setting of acute ischemic stroke. Methods: Symptomatic carotid artery stenosis of ≥50% was imaged using NaF-PET within 14 days of ipsilateral ischemic stroke. Symptomatic arteries were compared to contralateral asymptomatic carotid arteries. NaF dose was 125 MBq with 60 minute uptake on a GE Discovery 690 with 64 slice computed tomography. NaF uptake was measured using standardized uptake values for each artery’s single region of maximum uptake (SUVmax) and the mean of the three slices representing the most diseased segment (MDS-SUVmax). Arteries were compared using Wilcoxon signed-rank testing. Results: Fifty-two carotid arteries were analyzed: 26 symptomatic, 26 asymptomatic. Median SUVmax was higher in symptomatic than asymptomatic arteries: 2.16 (IQR 0.76) and 1.88 (IQR 0.94) respectively (p&lt;0.001). MDS-SUVmax was 2.04 (IQR 0.66) in symptomatic and 1.76 (IQR 0.83) in asymptomatic carotids (p&lt;0.001). Calcium scores did not differ between symptomatic and asymptomatic arteries (p=0.34). Conclusions: The ability to identify culprit carotid atheroma using NaF-PET in vivo represents an important advance in vascular imaging. This has important implications for understanding atherosclerosis pathophysiology, as well as potential clinical applications to identify and risk-stratify vulnerable carotid atheroma.

Revascularization of TASC C/D Iliac Occlusion Extended to Common/Superficial Femoral Artery using a Mixed Endoluminal and Subintimal Technique through the RadioBrachial Access

Revascularization of TASC C/D Iliac Occlusion Extended to Common/Superficial Femoral Artery using a Mixed Endoluminal and Subintimal Technique through the RadioBrachial Access Background: Patients with Trans-Atlantic Inter Society Consensus (TASC) C and D iliac lesions extended to common and/or superficial femoral artery are a very challenging subset of patients. Objective: The aim of this study is to discuss the technical implication and short-term outcome of endovascular revascularization through the radio-brachial access using a mixed endoluminal and subintimal recanalization using a Mmxed endoluminal and subintimal technique. Methods: From January 2010 to Jannuary 2015 We prospectively enrolled 33 consecutive patients (mean age 79 ± 12.5 years) , with long (>80 mm) TASC C and TASC D symptomatic chronic iliac arteries occlusion extended to the common/superficial femoral artery, judged not candidates for surgery. Procedure was attempted through the left radial or brachial artery by means of a mixed endoluminal and subintimal recanalization technique using coronary and peripheral dedicated guidewires. Results: The procedure was successful in all but one case (96.9%), mean length and diameter of implanted stents were 160.4 ± 30.2 mm and 8.6 ± 1.4 mm (Everflex EV3 in 20 patients, Pulsar in 3 patients, Smart Flex in 10 patients) , respectively. The procedure was successful in 32/33 patients (96.9%): mean length and diameter of implanted stents were 160.4 ± 30.2 mm and 8.6 ± 1.4 mm (Everflex EV3 in 20 patients, Pulsar in 2 patients, Smart Flex in 10 patients) , respectively. Complications rate was 9.1% including two vessel ruptures and one distal embolization. Death rate was 3%. At a mean follow up of 18.1 ± 11.2 montshs, the primary and secondary patency rates were 90.1 and 96.9%, respectively with a significant improvement of ABI (0.29 ± 0.6 versus 0.88 ± 0.3, p<00.1) and Rutherford class (5.3 ± 0.8 versus 0.7 ± 1.9, P <0.01) compared to baseline. Conclusion: The described technique appeared to be effective and safe allowing for recanalization of long iliac occlusion extended to common/superficial femoral artery.

Treatment of Symptomatic Aberrant Subclavian Arteries

Treatment of Symptomatic Aberrant Subclavian Arteries

Treatment of Symptomatic Aberrant Subclavian Arteries

The aim of this study is to present experience with 10 patients with symptomatic aberrant subclavian artery (ASA) and aneurysm of ASA who underwent surgical treatment. From 2008 to 2011 10 patients with symptomatic aberrant subclavian artery (mean age 60 years [range 24-90 years]) were studied. Symptoms were dysphagia (n = 7), dyspnea (n = 4), acute chest pain (n = 1), respiratory distress syndrome (n = 1), superior cava syndrome, and shock (n = 1). Six patients had aneurysm formation of the ASA (mean diameter of 7.1 cm [range 3.0-12.4 cm]; rupture [n = 1], dissection [n = 1]). All data were analyzed retrospectively. Treatment was performed as a hybrid procedure in eight patients. This included thoracic endoluminal graft exclusion with revascularization of the ASA, a pure endovascular procedure with two occluders in one patient, and an open procedure in one patient with ligation of the aberrant artery through a thoracotomy. Three patients died during the early postoperative period owing to pulmonary complications. All three suffered from a symptomatic aneurysm, and two were treated as an emergency procedure. Median follow-up was 20 months (range 12-49 months). A symptomatic ASA and its associated aneurysmal formation should be excluded after diagnosis. In most cases, a hybrid procedure consisting of thoracic endografting and revascularization of the ASA is feasible.

Vulnerable plaques in the contralateral carotid arteries in symptomatic patients: A detailed ultrasound analysis

Background and aimCarotid plaques may represent a generalized atherosclerotic syndrome or a localized disease. The aim of this study was to assess the morphological and textural features of carotid plaques located contralateral to the symptomatic side and compare them with the symptomatic side and with plaques from asymptomatic patients. MethodsWe studied 66 arteries in 39 patients (mean age 70 ± 7 year, 33% females). Arterial plaques were classified as either symptomatic (n = 30), contralateral to symptomatic (n = 25) or asymptomatic (n = 11). We compared several plaque features between these groups including the mean values of the grey scale median (GSM), entropy, juxtaluminal black area (JBA) without visible echogenic cap, GSM of the JBA and surface irregularity. ResultsThe plaques contralateral to symptomatic arteries had similar morphological and textural features to those in the symptomatic arteries. In contrast, they had more vulnerable morphological and textural features than those in asymptomatic arteries: less smooth plaques (12% vs. 55%) and instead more often mildly irregular (60% vs 36%) or markedly irregular (28% vs. 9%; p = 0.03), lower GSM (26.2 ± 8 vs. 49.4 ± 14, p < 0.001) and lower GSM of the JBA (5.0 ± 3.6 vs. 11.4 ± 2.1, p = 0.008). The frequency of entropy and plaque calcification was similar in all groups. ConclusionSymptomatic patients with carotid artery disease seem to have similar morphological and textural features of vulnerability in the symptomatic and the contralateral carotid arteries, which are profound compared with asymptomatic carotid arteries. These findings support the concept of generalized carotid atherosclerotic pathology rather than incidental unilateral disease, and also emphasize a need for aggressive measures for plaque stabilization, particularly in symptomatic patients.