North American Symptomatic Carotid Endarterectomy Research Articles

Treatment for routine, symptomatic, carotid bulb atherosclerosis: Carotid endarterectomy and stenting are comparable.

![Graphic][1] The results of recent carotid artery stenting (CAS) vs carotid endarterectomy (CEA) randomized studies (CREST,1 SPACE,2 EVA3S,3 and ICSS4) have created conflict among surgical and endovascular communities over which procedure is preferred for secondary stroke prevention for symptomatic carotid stenosis. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST) established CEA as the gold standard for surgical treatment in the early 1990s. Carotid stenting has been held to the high standard of CEA, and in order to present a viable alternative surgical therapy, it must be effective at preventing strokes, durable, and safe, with complication rates comparable to CEA. Carotid stenting is a clinically effective procedure. CREST, SPACE, and EVA3S showed equivalent annual stroke rates for the 2 treatments in symptomatic patients after the initial 30 days (CEA vs CAS: 0.8 vs 0.6, 1.3 vs 1.4, and 0.7 vs 0.4, percent per year, respectively). The stroke-free survival curves in CREST for CEA and CAS are parallel after the perioperative period out to 4 years, indicating clinical durability. > The increase in minor stroke in the CAS group and the increase in perioperative MI in the CEA group offset one another, leading to the equivalent primary endpoint. Perioperative safety remains the controversial point; the 30-day stroke and death rate for the stented patients was over 2 times that of the surgical group in the EVA3S trial. In the ICSS trial, the CAS group suffered stroke or death twice as often as the CEA group. Complications rates were, at best, equivalent in the 2 groups in the SPACE trial (6.3% for CEA and 6.8% for CAS), with CAS not achieving noninferiority. Why the … [1]: /embed/inline-graphic-1.gif

Comparison of NASCET and WASID criteria for the measurement of intracranial stenosis using digital subtraction and computed tomography angiography of the middle cerebral artery

Intracranial large-artery atherosclerosis is considered a frequent cause of stroke worldwide, particularly in Asian populations. The current evidence suggests that symptomatic patients with severe stenosis may benefit from intracranial stents. There are two methods for calculating the degree of intracranial stenosis, Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) and North American Symptomatic Carotid Endarterectomy Trial (NASCET), but they have never been compared. A total of 25 patients with suspected middle cerebral artery (MCA) stenosis based on their acute presentation were imaged by computed tomography angiography (CTA), then confirmed by digital subtraction angiography (DSA). Measurements were carried out on symptomatic MCA using both methods for determining the degree of stenosis. The degree of stenosis was significantly different using NASCET and WASID methods in DSA (48.2% vs. 54.6%; P<0.01), whereas CTA values did not differ significantly (54.2% vs. 52.0%; P = 0.9). All measurements were highly correlated between methods (Spearman r = 0.92 and 0.89, respectively; P<0.01). The results of this study suggest that NASCET and WASID measures are, on average, generally similar, although substantial disagreement in a given patient may be seen.

SPREAD-STACI Study: A Protocol for a Randomized Multicenter Clinical Trial Comparing Urgent with Delayed Endarterectomy in Symptomatic Carotid Artery Stenosis

In patients with >50% carotid artery stenosis (as measured by North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria) suffering a transient ischemic attack or a minor ipsilateral stroke, carotid endarterectomy exerts maximum benefits, when performed within the first 15 days from the initial ischemic symptom. It is also known that the probability of a major stroke spikes within the first few days after a transient ischemic attack/minor stroke and then flattens out in the following days and weeks. It could be hypothesized that urgent carotid endarterectomy has greater benefit than delayed procedure. Demonstrate that urgent carotid endarterectomy is more effective than delayed interventions. Centers employing neurolgist/stroke physicians and vascular surgeons will enroll TIA or minor stroke patients with >50 % carotid artery stenosis (Nascet criteria), randomized in two groups: urgent carotid endarterectomy (within 48 hours) and delayed carotid endarterectomy ( operated between 48 hours and 15 days after onset of symptoms) Risk factors will be evaluated at enrollment. TIA will be classified by ABCD2 scoring system,and minor stroke by National Institutes of Health Stroke Scale (NIHSS) scores. The study will last 90 days per patient,starting from their initial symptom,and the follow-up will be performed by an indipendent neurologist. A total of 456 patients (228 / group) is needed to observe an absolute difference of 10% between groups. Primary end-point is reduction in all types of stroke, AMI or death in urgent endarterectomy groupo compared to delayed ones. Secondary end-points are: Reduction of ipsilateral ischemic stroke in group 1 with respect to Group 2 Identification of predictive risk factors and Confirmation of no different rate for hemorragic/ischemiccomplications between groups.

Relationships Between Recent Intraplaque Hemorrhage and Stroke Risk Factors in Patients With Carotid Stenosis

Intraplaque hemorrhage (IPH) is an emerging marker of plaque instability. However, little is known about the relationships between IPH and traditional risk factors and whether these relationships differ between symptomatic and asymptomatic disease. Two hundred thirty-four patients with symptomatic (n=114) or asymptomatic (n=120) carotid stenosis underwent high-resolution plaque magnetic resonance imaging. Seventy-five patients had recent IPH (symptomatic, 33%; asymptomatic, 31%). In symptomatic stenosis, recent IPH was independently associated with degree of stenosis (odds ratio [OR]=4.21, 1.61-10.98 for North American Symptomatic Carotid Endarterectomy Trial >35%; OR=2.92, 1.18-7.24 for European Carotid Surgery Trial >60%), qualifying event (OR=4.13; 1.11-15.32 for stroke or hemispheric transient ischemic attack ≥1 hour versus transient ischemic attack <1 hour or ocular symptoms), time from ischemic event (OR=6.65, 1.56-28.35 for ≤2 weeks; OR=2.24, 0.87-5.81 for 2-12 weeks versus >12 weeks; P for trend=0.03). In asymptomatic stenosis, IPH was only associated with stenosis severity >70% by ECST (OR=6.65; 1.95-22.73) but not by the NASCET method. Our findings support the potential link between recent IPH and risk of ipsilateral stroke in symptomatic disease but also imply that prognostic studies should adjust for known stroke risk factors in multivariate analyses. In asymptomatic stenosis, the potential predictive value of recent IPH is less likely to be confounded by stroke risk factors.

Circulating Lipoprotein-associated Phospholipase A2 in High-grade Carotid Stenosis: A New Biomarker for Predicting Unstable Plaque

Objective To test plasma levels of lipoprotein-associated phospholipase A2 (Lp-PLA2) in patients with high-grade carotid stenosis according to plaque histology. Methods This cross-sectional single-centre study included patients with ≥70% North American Symptomatic Carotid Endarterectomy Trial (NASCET) carotid stenosis, who were treated surgically. Serum Lp-PLA2 and high-sensitivity C-reactive protein (hs-CRP) were determined on the day of surgery. Histopathological analysis classified carotid plaque as stable or unstable, according to AHA classification. Results Of the 42 patients (mean age 70.4 ± 10.5 years; 67% men), neurological symptoms were present in 16 (38%). Unstable plaques were found in 23 (55%). Median plasma level of Lp-PLA2 was significantly higher in patients with unstable plaque compared to those with stable plaque (222.4 (174.9–437.5) interquartile range (IQR) 63.5 vs. 211.1 (174.9–270.6) IQR 37.2 ng ml −1; p = 0.02). Moreover, median Lp-PLA2 level were higher in asymptomatic patients with unstable plaque (226.8 ng ml −1 (174.9–437.5) IQR 76.8) vs. stable plaque (206.9 ng ml −1 (174.9–270.6) IQR 33.7; p = 0.16). Logistic regression showed that only the neurological symptoms (OR = 30.9 (3.7–244.6); p < 0.001) and the plasma Lp-PLA2 level (OR = 1.7 (1.1–12.3); p = 0.03) were independently associated with unstable carotid plaque as defined by histology. Conclusions This study showed that circulating Lp-PLA2 was increased in patients with high-grade carotid stenosis and unstable plaque. Lp-PLA2 may be a relevant biomarker to guide for invasive therapy in asymptomatic patients with carotid artery disease.

Association Between Estrogen Receptor-α PvuII and XbaI Gene Polymorphisms With Extracranial Carotid Stenosis

Background: To determine whether estrogen receptor-α (ESR1) PvuII and XbaI gene polymorphisms affect carotid artery atherosclerosis in an Iranian population. Methods: There were 445 consecutive patients referred for isolated coronary artery bypass graft (CABG) surgery at our center registered in the study. The subjects were classified into 2 major categories with (≥50%) and without (<50%) carotid stenosis. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), the presence of PvuII and XbaI polymorphism within the ESR gene were analyzed. Results: Even after controlling for age, male sex, cigarette smoking, dyslipidemia, diabetes, and hypertension in a multivariable analysis, PvuII and XbaI polymorphisms were not found to be associated with the occurrence of carotid stenosis ≥50% ( P =0.626 and P =0.992, respectively). Conclusion: Our data suggests that ESR1 PvuII and XbaI gene polymorphisms did not have an effect on carotid artery stenosis in an Iranian population undergoing CABG. * ESR1 : estrogen receptor-α CABG : coronary artery bypass graft PCR-RFLP : polymerase chain reaction-restriction fragment length polymorphism CVD : cardiovascular disease ESR2 : estrogen receptor-β SNPs : single-nucleotide polymorphisms CAD : coronary artery disease LDL : low-density lipoprotein HDL : high-density lipoprotein NASCET : North American Symptomatic Carotid Endarterectomy Trial EDTA : ethylenediaminetetraacetic acid ANOVA : analysis of variance IMT : intimal-medial thickening

Carotid stenosis evaluation by 64-slice CTA: comparison of NASCET, ECST and CC grading methods

Purpose is to evaluate the intraobserver and interobserver variability of the North American Symptomatic Carotid Endarterectomy Trial (NASCET), European Carotid Surgery Trial (ECST) and Common Carotid (CC) methods, which are used to measure the degree of ICA stenosis, using 64-slice CT angiography and to compare the measurements made by these three methods. 88 cases (111 carotid arteries) were included in the study. Carotid CTA was performed by a 64 slice scanner (Toshiba, Aqullion 64).Two radiologists measured the degree of carotid stenosis by using NASCET, ECST and CC methods. Intraobserver and interobserver variability of each method was determined by intraclass correlation coefficient (ICC), Bland-Altman plots and kappa and linear weighted kappa statistics. The relation between the measurements was assessed by correlation coefficient (with linear and quadratic methods). Correlation coefficients showed that there is linear correlation between the measurements made by the three methods. The degree of stenosis measured with the NASCET method had the lowest value, while the corresponding values measured with the ECST and CC methods were close to each other. ICC and Bland-Altman plots showed high intra and inter observer agreement for NASCET, ECST and CC methods whereas kappa statistics showed moderate to substantial agreement. CC method had slightly higher agreement when compared with the other two methods. Intra and interobserver agreement is high for NASCET, ECST and CC methods however CC method has a slightly higher reproducibility. There is linear correlation between the measurements made by the three methods.

Histopathological features with angiographic correlates of internal carotid artery pseudo-occlusion: impact of plaque compositions

This study describes clinicopathological characteristics of pseudo-occlusion of the internal carotid artery with regard to its possible mechanisms. The authors retrospectively reviewed 17 patients with pseudo-occlusion and 23 with high-grade stenosis (North American Symptomatic Carotid Endarterectomy Trial criteria ≥ 90%, but no collapsed distal internal carotid artery) who underwent carotid endarterectomy. Atherosclerotic risk factors, clinical presentation, angiographic findings, and histological features of plaque obtained from the carotid endarterectomy were investigated and comparisons were made between groups. Plaques obtained in the pseudo-occlusion group were significantly more fibrous and less atheromatous than those in the high-grade stenosis group. Old, organized thrombi were more frequently found in pseudo-occlusion group plaques than in high-grade stenosis group plaques. Plaques acquired in the pseudo-occlusion group had 2 different histological features: the presence or absence of the original lumen. The pseudo-occlusion plaques with total occlusion and recanalization (8 patients) were composed of thrombotic total occlusion with lumen recanalization by large neovascular channels, whereas those with severe stenosis (9 patients) were fibrous or fibroatheromatous and had severe stenosis of the original lumen. In patients with pseudo-occlusion and total occlusion and recanalization, the authors observed a significantly higher incidence of transient ischemic attack and anterior communicating artery-posterior communicating artery collateral flow than those with high-grade stenosis and pseudo-occlusion with severe stenosis. Plaques of the pseudo-occlusion group were more fibrous than those of the high-grade stenosis group and had 2 different histological features: pseudo-occlusion with total occlusion and recanalization or pseudoocclusion with severe stenosis. This difference in plaque histology may be related to the clinical features of pseudoocclusion, such as symptoms and collateral flow patterns.

Carotid Endarterectomy in Academic Versus Community Hospitals: The National Surgical Quality Improvement Program Data

Carotid endarterectomy (CEA) is among the most commonly performed vascular operations in both academic and community hospital settings. The excellent results of the large prospective studies (North American Symptomatic Carotid Endarterectomy Trial, Asymptomatic Carotid Atherosclerosis Study) have been criticized because of a widely held impression that community hospitals could not duplicate the excellent surgical results achieved in high volume university hospitals or clinics. The purpose of this study was to use the National Surgical Quality Improvement Program data to evaluate the outcomes of CEA in academic versus community hospitals. All patients undergoing CEA were identified in the National Surgical Quality Improvement Program database conducted between January 1, 2005 and October 30, 2009. The patients were stratified on the basis of the hospital of care: academic hospital or community hospital. All postoperative outcomes were analyzed. A total of 17,388 CEAs met the inclusion criteria, among which 9,649 cases were performed at an academic institution and 7,739 cases were performed at a community hospital. There were more women in the community hospital cohort (42.5% vs. 40.2%, p = 0.0197). Preoperatively, the community hospital cohort had more patients with dyspnea (22.8% vs. 18.1%, p < 0.0001), chronic obstructive pulmonary disease (COPD) (10.7% vs. 9.7%, p = 0.0322), angina (2.6% vs. 1.9%, p = 0.0021), previous stroke with no deficit (9.0% vs. 7.6%, p = 0.0009), and past transient ischemic attacks (28.3% vs. 25.1%, p < 0.0001). The academic hospital cohort had more patients with recent alcohol use (4.5% vs. 3.8%, p = 0.0245), cardiac surgery (24.0% vs. 22.5%, p = 0.0206), and hemiplegia (4.8% vs. 4.1%, p = 0.0288). Postoperatively, there was no difference in the two groups in 30-day stroke rate (1.2% vs. 1.5%, p = 0.1035), 30-day myocardial infarction rate (0.5% vs. 0.6%, p = 0.2149), or 30-day mortality rate (0.5% vs. 0.6%, p = 0.6335). The overall combined 30-day stroke, myocardial infarction, and mortality rates were not different between the two groups (2.2% vs. 2.7%, p = 0.0568). In the asymptomatic patient cohort, there were a total of 9,285 cases, with 5311 cases performed at an academic institution and the remainder at community hospitals. Preoperatively, the community hospitals had more patients with dyspnea (78.3% vs. 82.1%, p < 0.0001). The academic cohort had more patients with acute renal failure (0.3% vs. 0.1%, p = 0.0426). Postoperatively, there was no difference in the two groups in 30-day stroke rate (0.9% vs. 1.1%, p = 0.2899), 30-day myocardial infarction rate (0.4% vs. 0.5%, p = 0.4348), or 30-day mortality rate (0.5% vs. 0.4%, p = 0.6370). The overall combined 30-day stroke, myocardial infarction, and mortality rates were not different between the two groups (1.8% vs. 2.0%, p = 0.4394). CEA is widely performed in both academic and community hospital settings. This study demonstrates that the results are equivalent and have equally good 30-day outcomes in both asymptomatic and combined populations.

Small Carotid Thrombus and Minimal Stenosis Causing Repeated Embolic Strokes

Despite current developments in neuroradiology, the sources of infarctions go undiagnosed in 28% of cases. An embolic source in the setting of minimal stenosis at the carotid bifurcation has rarely been reported. The authors report a previously healthy 48-year-old woman, without any risk factors for cerebrovascular events, sustained multiple cerebral infarctions in the right anterior and middle cerebral artery territory. Repeated imaging of the heart and cerebral vessels missed a very small abnormality arising from the posterior wall of the internal carotid artery, until it was diagnosed by computed tomographic angiography. This is problematic because by North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria, minimal stenosis essentially excludes the carotid artery as an embolic source. Despite maximum antiplatelet and anticoagulation therapy, she continued to have neurological deteriortation by progression of her strokes. She underwent standard carotid endarterectomy and sustained no new embolic phenomena. Histopathological examination showed an endothelial hyperplasia with organizing thrombus, which on the posterior wall of the internal carotid artery, is likely a hemodynamically induced on top of preexisting atherosclerotic plaque.

Measurement of carotid artery stenosis: correlation analysis between B-mode ultrasonography and contrast arteriography

PurposeTo evaluate the efficacy of B-mode ultrasonography (US) in measurement of carotid stenosis% (CS%).MethodsOne hundred and thirth-three carotid arteries in 96 patients who underwent both carotid US and carotid arteriography (CA) were included in this retrospective study. To measure CS% on US, a cross sectional view of the most stenotic segment of the internal carotid artery was captured and residual diameter and original diameter of that segment were measured with electronic caliper on the same plane and in the same direction. To measure CS% on an angiogram, we used European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) methods. Pearson's correlation analysis and linear regression analysis were used to determine the correlation between CS% on an US and angiogram.ResultsPearson's correlation coefficient (R) between CS% measured in US and CA were 0.853 (ECST method, P < 0.001) and 0.828 (NASCET method, P < 0.001). Accuracies of B-mode US were 93.2%, 88.0%, and 81.2% for estimating CS% by ECST method and 86.5%, 82.7%, and 82% for estimating CS% by NASCET method.ConclusionCS% measured in B-mode US was simpler and showed a strong positive correlation with that measured on an arteriogram either ECST or NASCET method.

Part One: For the Motion Carotid Disease is Rarely Responsible for Stroke after Coronary Bypass Surgery

Part One: For the Motion Carotid Disease is Rarely Responsible for Stroke after Coronary Bypass Surgery

Carotid stent removal of symptomatic plaque protrusion after carotid angioplasty stenting

We treated two patients with asymptomatic high grade internal carotid artery stenosis, by carotid artery stenting (CAS) with embolus protection filters 75% and 70%, respectively (North American Symptomatic Carotid Endarterectomy criteria). The immediate cranial and carotid angiogram showed a good result with regular patency of carotid and cerebral vessels. In both cases, the CAS procedure was complicated with symptomatic embolism, in one case 6 h after CAS and the other one occurring after seven days. The duplex scan (DS) control revealed the presence of plaque protrusion intra-stent in both cases. An early treatment with stent removal and carotid surgery was performed <24 h after the presenting symptoms (in one case a standard endarterectomy in the other and a carotid bypass was performed). Both patients were discharged without neurological deficit. At neurological follow-up at 30 days the patients were in good general condition without neurological symptoms or deficit and the DS follow-up at 30 days and six to 12 months show the patency of carotid vessels. These two cases demonstrate that plaque protrusion is a possible complication of CAS, where symptoms which may occur either immediately or later and can be managed successfully with urgent surgical intervention of carotid stent removal.

Importance of Validation of Accuracy of Duplex Ultrasonography in Identifying Moderate and Severe Carotid Artery Stenosis

The accuracy of carotid duplex ultrasonography (CDU) in detecting moderate and severe carotid artery disease was evaluated in comparison with arteriography. Accuracy of CDU was correlated with arteriographic findings using North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria in 147 internal carotid arteries. The duplex measurements consisted of peak systolic velocities (PSVs), end diastolic velocities (EDVs), and internal carotid PSV to common carotid artery PSV ratios (ICA/CCA). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy (OA) using the 3 parameters were determined. Receiver operating characteristic (ROC) curves were constructed from the ultrasonographic data for detection of 50% or greater stenosis (moderate disease) and 70% or greater stenosis (severe disease). CDU for detecting ≥ 50% stenosis had a sensitivity of 100%, specificity of 87.8%, and accuracy of 96.6%. The area under the ROC curves for PSV was 0.86 (95% confidence interval [CI] 0.80-0.93), for EDV was 0.86 (95% CI 0.80-0.92), and for ICA:CCA ratio was 0.95 (CI 0.91-0.99). CDU for detecting ≥ 70% stenosis had a sensitivity of 100%, specificity of 87.1%, and accuracy of 94.5%. The area under the ROC curves for PSV was 0.76 (95% CI 0.68-0.84), for EDV was 0.74 (95% CI of 0.65-0.82), and for ICA/CCA ratio was 0.89 (0.84-0.94). We conclude that ≥ 50% stenosis and ≥ 70% stenosis can be reliably determined by CDU in our vascular laboratory. Each vascular laboratory must validate their own criteria against the current gold standard of carotid arteriography. A high degree of confidence in CDU is critical before any institution uses the test as the sole diagnostic method prior to carotid intervention.

Correlation between kinking and coiling of the carotid arteries as assessed using MDCTA with symptoms and degree of stenosis

To evaluate whether the presence of kinking and coiling of the carotid arteries is associated with symptoms and an increased degree of carotid artery stenosis. One hundred and fifty-three consecutive patients examined using multidetector-row computed tomography angiography (MDCTA) were studied retrospectively. The arterial phase was obtained by injecting 4-6ml/s of contrast material. A total of 306 carotid arteries were assessed for the presence of tortuosity. The degree of carotid artery stenosis was measured according to North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Logistic regression analysis was performed to determine whether an independent association existed between the presence of vessel tortuosity, symptoms, and the degree of carotid artery stenosis. Kinking was detected on 37 occasions (12.1%) and coiling on 20 occasions (6.5%). Using Yates's corrected chi-square test, an association between kinking and symptoms (p=0.002) was observed, but not between coiling and symptoms (p=0.31). Logistic regression confirmed that the strongest association was present between stenosis degree and symptoms (p=0.001), but kinking (p=0.009) and age (p=0.001) were also significantly associated with symptoms. A Mann-Whitney test did not demonstrate correlation between coiling (p=0.16) or kinking (p=0.22) and increased degree of carotid artery stenosis. The results suggest that kinking may be associated with symptoms, whereas coiling does not appear to be associated with symptoms. The degree of carotid artery stenosis severity is not related to the presence of vessel tortuosity.

Automatic Lumen Segmentation in Calcified Plaques: Dual-Energy CT Versus Standard Reconstructions in Comparison With Digital Subtraction Angiography

Dual-energy CT has the potential to automatically remove calcified plaques from angiographic data sets. The objective of this study is to compare the accuracy of visual grading of stenoses after plaque removal with visual grading in standard reconstructions. Digital subtraction angiography (DSA) was used as a reference standard. Twenty-five patients underwent dual-energy CT (140 kV and 80 mAs; 80 kV and 234 mAs) angiography and DSA. Plaque and bone removal was performed. Twenty-nine calcified stenoses were quantified using standard reconstructions, plaque and bone removal maximum intensity projections after plaque and bone removal, and DSA images, according to the North American Symptomatic Carotid Endarterectomy Trial criteria. The accuracy of the detection of relevant stenoses (> 70%) and occlusions was assessed. Correlation coefficients of the grades of stenoses with DSA were calculated. The influence of vessel enhancement on the accuracy of plaque removal was analyzed. The average postprocessing time was 45 seconds. After plaque removal, all 25 relevant and four nonrelevant stenoses were correctly detected. Six relevant stenoses were overestimated as complete occlusions. With the standard reconstructions, two nonrelevant stenoses were overestimated as relevant. Correlation coefficients (r(2)) for the grading of stenoses after plaque removal and with standard reconstructions versus DSA were 0.7694 and 0.4329, respectively. Vessel contrast enhancement correlated weakly (r(2) = 0.2072) with the accuracy of plaque removal. Dual-energy CT with plaque removal automatically delivers CT luminograms with a high sensitivity for the detection of relevant stenoses and a higher correlation to DSA than standard reconstructions but frequently leads to an overestimation of high-grade stenoses as occlusions. Thus, dual-energy CT plaque and bone removal should be used complementary to standard reconstructions, and not exclusively.

HYPERTENSION AND CAROTID ARTERY STENOSIS. A CORRELATIVE STUDY BY USING MULTI-DETECTOR-ROW CT ANGIOGRAPHY: PP.18.212

Objective: Carotid artery stenosis is the major risk factor for ischemic stroke. Our purpose was test the hypothesis of a correlation between carotid artery stenosis and hypertension by using multi-detector-row CT angiography (MDCTA). Design and Method: 104 consecutive patients studied by using a MDCTA, for an overall number of 208 carotid arteries, were retrospectively studied. The following features were analysed: degree of the stenosis (on the basis of North American Symptomatic Carotid Endarterectomy Trial criteria) the composition of the plaque and course anomalies, and presence of plaque's ulcerations. For each patient we generated post-processed images by using Maximum Intensity Projection (MIP), Multi-Planar Reconstruction (MPR) and Volume Rendering (VR) techniques. Results: We detected seventy-one patients with significant stenosis; patients with hypertension were 55, (43 with stenosis and 12 without stenosis). We did not observe a significant statistical correlation (p = 0.142). Conclusions: Results of our work suggest that there is not a significant statistical association between carotid artery stenosis and hypertension, although there is a visible trend in patients (p = 0.142) with carotid artery stenosis towards hypertension.

Asymmetric diabetic retinopathy

Diabetic retinopathy is primarily a microangiopathy. In response to the ischemia, retinal tissues release various angiogenic and inflammatory factors that enhance vascular growth and permeability, leading to progression of diabetic retinopathy. The fundoscopic findings in the vast majority of patients tend to be symmetrical. Asymmetric findings should prompt further investigation. A 73-year-old man with Type 2 diabetes mellitus for the past 15 years was routinely followed-up on an annual basis in the eye clinic. Over the duration of follow-up, fundoscopy had shown only minimal background diabetic retinopathy. Over a period of 10 months, the patient developed very marked asymmetric retinopathy that was resistant to extensive treatment with panretinal photocoagulation. During this period, the patients HbA1c was 8.6%. His medical history included hypertension and hypercholesterolemia, for which he was on oral medication. He also had a history of peripheral vascular and ischemic heart disease. At examination, corrected visual acuities were 6/12 in the right eye and 6/6 in the left eye. The right fundus had extensive proliferative changes, with a fan of new vessels arising from the optic disc with an inner fibrous band. In contrast, the left fundus showed signs of mild non-proliferative diabetic retinopathy (Fig. 1). Ocular examination was otherwise normal. In view of the asymmetry in the severity of the patient’s diabetic retinopathy and his history of vascular disease, underlying ocular ischemic syndrome (OIS) was suspected. Clinical fundus photographs showing the (a) left and (b) right fundi of a 73-year-old diabetic man with severe right carotid artery stenosis. Further examination revealed a considerably reduced right carotid artery pulse. This was subsequently confirmed by Doppler studies that showed near complete occlusion of the right internal carotid artery and 50% stenosis of the left internal carotid. Carotid stenosis was undoubtedly the predominant factor in producing such marked asymmetric retinopathy. The resultant ocular ischemia caused by aortic arch atherosclerosis or by stenosis of the carotid arteries may cause neovascularization of the iris, disc, and peripheral retina. Although panretinal photocoagulation may be of some benefit in such patients, the outcome is usually less successful, perhaps because the vasoproliferative stimulus is so intense and diffuse within the eye. A variable spectrum of signs and symptoms may result from chronic ocular hypoperfusion. Collectively, they may be encompassed under the heading of OIS. This was first described by Kearns and Hollenhorst in 1963.1 The mean age at presentation is usually 65 years and the condition affects men twice as frequently as it does women. In 20% of cases, the syndrome affects both eyes. Symptoms of OIS include decreased vision, eye pain (including a dull ache over the eyebrow) and a history of transient ischemic attacks or amaurosis fugax. A constellation of signs may be seen in the fundus, including retinal arterial narrowing, retinal venous dilatation without tortuosity, retinal hemorrhages and microaneurysms, pulsation of the retinal arteries, cotton wool spots, and retinal neovascularization. Differentiation from proliferative diabetic retinopathy may, indeed, be difficult. Usually, OIS is associated with widespread atherosclerosis: 50% of patients have evidence of previous ischemic heart disease, whereas previous cerebrovascular accidents have occurred in 25% of patients.2 The severity of the syndrome is reflected by a 40% 5-year mortality rate, the main cause of death being ischemic heart disease.2 The presentation of marked asymmetric retinopathy should raise suspicion of OIS and should prompt urgent investigation of blood supply to the head and neck, namely the patency of the carotid arteries. Indeed, reversal of the carotid stenosis may be the most important avenue to maintain or improve vision in such cases. The North American Symptomatic Carotid Endarterectomy Trial3 found that the 2-year stroke rate was 9% in patients who had undergone carotid endarterectomy compared with 26% in patients only managed with antiplatelet therapy. However, the decision to undertake carotid endarterectomy may be difficult given the high rate of immediate postoperative risk of severe stroke (2.1%) compared with only 0.9% in patients treated with antiplatelet therapy.3 In summary, marked asymmetrical diabetic retinopathy should raise suspicion of OIS and prompt further investigation. This is important because OIS is associated with high morbidity and mortality from both ischemic heart disease and cerebrovascular accident. Early intervention, including carotid endarterectomy, may result in improved outcome for these patients.

Comparison Between Quantification Methods of Carotid Artery Stenosis and Computed Tomographic Angiography

The purpose of this study was to compare 3 percentage carotid artery measurement methods (the North American Symptomatic Carotid Endarterectomy Trial [NASCET], the European Carotid Surgery Trial [ECST], and the Carotid Stenosis Index [CSI]) and 1 millimeter method (direct millimeter measurement) to evaluate the difference and correlation between them. Seven hundred ninety-two patients (591 men; age: mean, 63 years; range, 32-91 years) studied by using a multi-detector row computed tomographic scanner for a total of 1584 carotid arteries were retrospectively analyzed. Each carotid stenosis was measured according to 4 measurement methods (the NASCET, the ECST, the CSI, and the direct millimeter measurement). Carotid arteries with near-occlusion condition were excluded. The Kolmogorov-Smirnov Z test was used to test the normality of continuous variable groups. Comparison of derived ratio-percent methods was performed by using the Bland-Altman plots, and receiver operating characteristic curves were calculated. Correlation coefficients were also calculated by using a nonparametric Spearman correlation. A P < 0.05 was considered to mean statistical significance. Four hundred sixteen carotid arteries were excluded, and in the remaining 1168 ones, a strength correlation according to quadratic regression between the NASCET and ECST methods was observed (Spearman rho coefficient, 0.948; P < 0.0001). An inverse correlation according to linear regression was observed between the NASCET and the direct millimeter measurement (Spearman rho coefficient, -0.972; P < 0.0001); the CSI shows a quadratic regression with the NASCET, a linear regression with the ECST, and an inverse linear regression with the direct millimeter measurement (Spearman rho coefficient, 0.946, 0.932, and -0.939 respectively). The cutoff values for 50% and 70% NASCET stenosis were 2.36 and 1.51, respectively. Our study results indicate that the direct millimeter measurement of stenosis, by using appropriate equations, can reliably predict NASCET-, ECST-, and CSI-type percent stenoses. The use of direct millimeter measurement may remove the pitfalls and the discrepancies deriving from the use of different ratio-percent methods.

Ultraschallkriterien zur Graduierung von Stenosen der A. carotis interna – Revision der DEGUM-Kriterien und Transfer in NASCET-Stenosierungsgrade

Since 1986, German ultrasound criteria for grading carotid stenosis have followed the local diameter reduction percentage consistent with the definition used in the European Carotid Surgery Trial (ECST) definition. To overcome the confusion caused by the coexisting grading method used in the North American Symptomatic Carotid Endarterectomy Trial (NASCET), a German interdisciplinary council on carotid artery stenosis has recommended the implementation of the NASCET grading system (distal diameter reduction percentage) as the standard. The multi-parametric German "DEGUM ultrasound criteria" consisting of combined Doppler and imaging criteria have consequently been revised and transferred to the NASCET definition. In addition, a novel differentiation between main (primary) and additional (secondary) criteria has been proposed. When these ultrasound criteria are combined, vascular sonography allows reliable grading of carotid disease.