Elie Chakhtoura - Academia.edu (original) (raw)

Papers by Elie Chakhtoura

Research paper thumbnail of Plaque morphology directly related to platelet activation in ACS

Current Controlled Trials in Cardiovascular Medicine, 2000

Context A new study provides prospectively established evidence of a direct association between p... more Context A new study provides prospectively established evidence of a direct association between platelet activation and plaque rupture in patients with unstable angina. Those with angiographically documented complex lesions had significantly greater expression of both the activation-dependent platelet epitope CD63 and glycoprotein IIb/IIIa aggregation sites on the platelet membrane. These factors indicate intense thrombogenic potential and could potentially be used in risk stratification for acute coronary events. Significant findings The authors report that patients with unstable angina were characterized by 39% higher levels of fibrinogen than those with stable angina (423 ? 304 versus 304 ? 51 mg/dl, P = 0.004). Compared with patients with stable angina, those with unstable angina had a five-fold higher percentage of platelets positive for activation-dependent CD63 (14.6 ? 5.6% versus 2.75 ? 1.6%, P = 0.0026) and a 15% higher expression of glycoprotein IIa/IIIb (517 ? 79 versus 449 ? 50, P = 0.038). Comments The raised levels of CD63 provide direct evidence of platelet activation and correlate with angiographic evidence of complex ulcerated lesions, the authors write. Moreover, the pathophysiologic findings further support the clinically proven pivotal role of IIa/IIIb inhibitors in the treatment of

Research paper thumbnail of Abstract 4: Angiographic Predictors of Stroke after Carotid Artery Stenting - A Qualitative and Quantitative Analysis of 1070 Patients in the Carotid Revascularization Endarterectomy versus Stenting Trial

Research paper thumbnail of Outcome of Carotid Artery Stenting for Primary versus Restenotic Lesions

Annals of Vascular Surgery, Jan 5, 2009

Carotid artery stenting (CAS) for restenosis (RS) after carotid endarterectomy (CEA) is presumed ... more Carotid artery stenting (CAS) for restenosis (RS) after carotid endarterectomy (CEA) is presumed to have fewer complications than CAS for primary atherosclerotic (PA) lesions. It has been proposed that interventionalists may limit themselves to CAS for RS initially, while they gain additional experience during their learning curve. However, there are few studies objectively comparing the outcomes of the two groups of patients to substantiate this assumption. We analyzed prospectively collected data on CAS performed at our institution from 1996 to April 2006. Complication rates were compared between CAS performed for RS versus PA lesions. Specific end points studied included in-hospital and 30-day stroke and death rates. The incidence of transient ischemic attack (TIA) was also recorded. Patient demographic features (gender, age, hypertension, diabetes mellitus, coronary artery disease, smoking, hypercholesterolemia, and presence of preoperative neurological symptoms) were recorded. A neurologist examined all patients before and after CAS. Patients with previous CAS with in-stent RS and tandem common carotid artery-internal carotid artery or arch ostial stenoses were excluded from this analysis. CAS procedures (n ¼ 217) performed on 210 patients fulfilled inclusion criteria for this study. Indications for CAS included RS (n ¼ 118, 54%) and PA (n ¼ 99, 46%). The two groups were well matched for all demographic features except hypercholesterolemia, which was more common in the PA group. Thirty-day stroke and stroke + death rates for the entire series were 2.8% and 4.1%, respectively. Within this cohort, 30-day stroke and stroke + death rates were not significantly different between the RS (2.5% and 5.1%) and PA (3.0% and 3.0%) groups. Within the RS group, these outcomes were also similar when patients treated for late recurrence (>24 months after CEA, n ¼ 49) were compared to those treated for early recurrence (24 months after CEA, n ¼ 67). Only when stroke and TIA were combined was a difference observed between the late recurrence (10.0%) and the early recurrence (1.5%) groups ( p ¼ 0.049). Contrary to general opinion, 30-day stroke and stroke + mortality rates from CAS for RS versus PA were not significantly different. Lower neurological event rates were only seen in CAS for early RS compared with late RS after endarterectomy when TIAs were included as an end point in the analysis. CAS for RS must therefore not be considered a low-risk procedure. Technical proficiency for CAS must be equivalent regardless of the etiology of the stenosis. These observations also underscore the need for appropriate patient selection and close follow-up of all patients undergoing CAS.

Research paper thumbnail of Abstract 1: Did Carotid Stenting and Endarterectomy Outcomes Change Over Time in the Carotid Revascularization Endarterectomy versus Stenting Trial?

Research paper thumbnail of Temporal Changes in Periprocedural Events in the Carotid Revascularization Endarterectomy Versus Stenting Trial

Stroke; a journal of cerebral circulation, Jan 14, 2015

Post-hoc, we hypothesized that over the recruitment period of the Carotid Revascularization Endar... more Post-hoc, we hypothesized that over the recruitment period of the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST), increasing experience and improved patient selection with carotid stenting, and to a lesser extent, carotid endarterectomy would contribute to lower periprocedural event rates. Three study periods with approximately the same number of patients were defined to span recruitment. Composite and individual rates of periprocedural stroke, myocardial infarction, and death rate were calculated separately by treatment assignment (carotid stenting/carotid endarterectomy). Temporal changes in unadjusted event rates, and rates after adjustment for temporal changes in patient characteristics, were assessed. For patients randomized to carotid stenting, there was no significant temporal change in the unadjusted composite rates that declined from 6.2% in the first period, to 4.9% in the second, and 4.6% in the third (P=0.28). Adjustment for patient characteristic...

Research paper thumbnail of Buddy wire" technique to overcome proximal coronary tortuosity during rotational atherectomy

The Journal of invasive cardiology, 2005

We report a case in which rotational atherectomy was planned for the treatment of a severely calc... more We report a case in which rotational atherectomy was planned for the treatment of a severely calcified obstructive lesion in the middle right coronary artery. Severe proximal vessel tortuosity prevented the advancement of the Rotablator burr. We utilized the "buddy wire" technique, allowing facilitated advancement of the Rotablator and successful atherectomy and stenting. We propose this old technique as an alternative method to allow advancement of the Rotablator burr through tortuous and calcified vessels.

Research paper thumbnail of Comparaison des résultats du stenting carotidien pour les lésions primitives carotidiennes et les lésions de resténose

Annales de Chirurgie Vasculaire, 2009

Le stenting carotidien (SC) pour rest enose (RS) apr es endart eriectomie carotidienne (CEA) est ... more Le stenting carotidien (SC) pour rest enose (RS) apr es endart eriectomie carotidienne (CEA) est pr esum e donner moins de complications que le SC pour l esions d'ath erome primitives (AP). Il a et e propos e que les op erateurs limitent au d ebut de leur exp erience le SC aux l esions de RS. Cependant, peu d' etudes comparant objectivement les r esultats obtenus dans ces deux groupes de patients ont et e publi ees et il n'est pas possible de valider cette hypoth ese. Nous avons analys e des donn ees collect ees prospectivement sur les patients ayant b en efici e d'un SC dans notre etablissement entre 1996 et avril 2006. Les taux de complication ont et e compar es entre les SC r ealis es pour RS et les SC r ealis es pour des l esions d'AP. Les crit eres de jugement sp ecifiques incluaient la mortalit e intra-hospitali ere, les taux d'accidents vasculaires c er ebraux et de mortalit e a 30 jours. L'incidence des accidents isch emiques transitoires a egalement et e analys ee. Les caract eristiques d emographiques des patients (sexe, â ge, hypertension, diab ete, coronaropathie, tabagisme, hypercholest erol emie, et pr esence de symptô mes neurologiques pr eop eratoires) ont et e analys ees. Tous les patients ont et e examin es par un neurologue avant et apr es le SC. Les patients ayant d ej a benefici e d'un SC et pr esentant une RS intra-stent, les patients pr esentant des st enoses en tandem des art eres carotides primitive et interne, ou ceux ayant une st enose ostiale au niveau de la crosse aortique ont et e exclus de cette analyse. Parmi 217 patients ayant b en efici e d'un SC, 210 ont rempli les crit eres d'inclusion pr e-d efinis. Les indications pour la r ealisation d'un SC ont inclus la RS (n ¼ 118, 54%) et l'AP (n ¼ 99, 46%). Les deux groupes etaient similaires pour ce qui concerne les caract eristiques d emographiques a l'exception de l'hypercholest erol emie, qui etait plus fr equente dans le groupe d'AP. Au total, le taux d'AVC et le taux combin e d'AVC + mortalit e a 30 jours etaient respectivement de 2.8% et 4.1%. Le taux d'AVC et le taux combin e d'AVC + mortalit e a 30 jours n' etaient pas significativement diff erents entre les groupes RS (2,5% et 5,1%) et AP (3,0% et 3,0%). Dans le groupe RS, les r esultats etaient similaires entre les patients trait es pour une RS tardive (>24 mois apr es la CEA, n ¼ 49) et ceux trait es pour une RS pr ecoce (24 mois apr es la CEA, n ¼ 67). Il existait une diff erence entre les patients pr esentant une RS tardive (10.0%) et ceux pr esentant une RS pr ecoce (1.5%) ( p ¼ 0.049) uniquement quand AVC et AIT etaient combin es. Contrairement a l'opinion g en eralement admise, les taux d'AVC a 30 jours et d'AVC + mortalit e a 30 jours apr es SC pour RS et pour AP n' etaient pas significativement diff erents. Des taux plus faibles d' ev enements neurologiques ont et e observ es uniquement lorsque le SC etait r ealis e pour RS pr ecoce en comparaison a la RS tardive et quand les AITs etaient inclus comme crit ere de jugement dans l'analyse. Le SC pour RS ne doit donc pas ê tre consid er e comme une proc edure a faible risque. La comp etence technique pour la r ealisation d'un SC doit ê tre equivalente 354 quelque soit l' etiologie de la st enose. Ces observations soulignent egalement la n ecessit e d'une s election rigoureuse et d'un suivi rapproch e des patients ayant b en efici e d'un SC.

Research paper thumbnail of Resultados del tratamiento con stent de las lesiones primarias de la arteria carótida frente a las reestenosis

Anales de Cirugía Vascular, 2009

Se supone que el tratamiento mediante la implantaci on de un stent carot ıdeo (SC) de las reesten... more Se supone que el tratamiento mediante la implantaci on de un stent carot ıdeo (SC) de las reestenosis ocurridas tras una endarterectom ıa carot ıdea (EAC) tiene menos complicaciones que la colocaci on de un SC en lesiones ateroscler oticas primarias (LAP). Se ha propuesto que los intervencionistas podr ıan limitar inicialmente el SC para los casos de reestenosis, mientras adquieren experiencia adicional durante la curva de aprendizaje. Sin embargo, existen pocos estudios que comparen de forma objetiva los resultados de ambos grupos de pacientes para sostener esta afirmaci on. Analizamos los resultados obtenidos de forma prospectiva sobre los SC implantados en nuestro centro desde 1996 hasta abril de 2006. Se compararon las tasas de complicaciones entre la implantaci on de un SC por reestenosis frente a LAP. Los criterios de valoraci on espec ıficos que se estudiaron fueron la tasa de ictus y de mortalidad intrahospitalarias y a los 30 d ıas. Se registr o adem as la incidencia de accidentes isqu emicos transitorios (AIT). Se registraron las caracter ısticas demogr aficas de los pacientes (sexo, edad, hipertensi on arterial, diabetes mellitus, arteriopat ıa coronaria, tabaquismo, hipercolesterolemia y presencia de s ıntomas neurol ogicos preoperatorios). Un neur ologo examin o a todos los pacientes antes y despu es de la implantaci on de un SC. Se excluy o del an alisis a los pacientes con un SC implantado previamente con restenosis intrastent, con estenosis en t andem de las arterias car otida com un e interna, y con lesiones ostiales del cayado a ortico. Cumplieron los criterios de inclusi on de este estudio 217 SC implantados en 210 pacientes. Las indicaciones para la implantaci on de un SC fueron la reestenosis (n ¼ 118, 54%) y la LAP (n ¼ 99, 46%). Las caracter ısticas demogr aficas de ambos grupos eran comparables a excepci on de la hipercolesterolemia, que fue m as frecuente en el grupo de LAP. Las tasas de ictus e ictus y mortalidad a los 30 d ıas de toda la serie fueron del 2,8 y 4,1%, respectivamente. En esta cohorte, las tasas de ictus e ictus m as mortalidad a los 30 d ıas no difirieron de forma significativa entre los grupos de pacientes con reestenosis (2,5 y 5,1%) y LAP (3,0 y 3,0%). En el grupo de pacientes con reestenosis, estos resultados tambi en fueron similares cuando se compar o a los pacientes tratados por una recurrencia tard ıa (> 24 meses tras la EAC, n ¼ 49) con los tratados por una recurrencia precoz ( 24 meses tras la EAC, n ¼ 67). La combinaci on de ictus y AIT fue la unica situaci on en la que se observaron diferencias entre los grupos de pacientes con recurrencia tard ıa (10,0%) y precoz (1,5%) (p ¼ 0,049). En contra de la opini on general, las tasas de ictus e ictus m as mortalidad a los 30 d ıas tras la implantaci on de un SC no difirieron de forma significativa entre los casos de restenosis y LAP. Se observaron unicamente unas tasas de episodios neurol ogicos con la implantaci on de SC en reestenosis precoces menores en comparaci on con las restenosis tard ıas tras EAC, cuando los AIT se incluyeron en el an alisis como criterio de valoraci on. Por tanto, la implantaci on de un SC en los casos de reestenosis no

Research paper thumbnail of Outcome of Carotid Artery Stenting for Primary versus Restenotic Lesions

Annals of Vascular Surgery, 2009

Carotid artery stenting (CAS) for restenosis (RS) after carotid endarterectomy (CEA) is presumed ... more Carotid artery stenting (CAS) for restenosis (RS) after carotid endarterectomy (CEA) is presumed to have fewer complications than CAS for primary atherosclerotic (PA) lesions. It has been proposed that interventionalists may limit themselves to CAS for RS initially, while they gain additional experience during their learning curve. However, there are few studies objectively comparing the outcomes of the two groups of patients to substantiate this assumption. We analyzed prospectively collected data on CAS performed at our institution from 1996 to April 2006. Complication rates were compared between CAS performed for RS versus PA lesions. Specific end points studied included in-hospital and 30-day stroke and death rates. The incidence of transient ischemic attack (TIA) was also recorded. Patient demographic features (gender, age, hypertension, diabetes mellitus, coronary artery disease, smoking, hypercholesterolemia, and presence of preoperative neurological symptoms) were recorded. A neurologist examined all patients before and after CAS. Patients with previous CAS with in-stent RS and tandem common carotid artery-internal carotid artery or arch ostial stenoses were excluded from this analysis. CAS procedures (n ¼ 217) performed on 210 patients fulfilled inclusion criteria for this study. Indications for CAS included RS (n ¼ 118, 54%) and PA (n ¼ 99, 46%). The two groups were well matched for all demographic features except hypercholesterolemia, which was more common in the PA group. Thirty-day stroke and stroke + death rates for the entire series were 2.8% and 4.1%, respectively. Within this cohort, 30-day stroke and stroke + death rates were not significantly different between the RS (2.5% and 5.1%) and PA (3.0% and 3.0%) groups. Within the RS group, these outcomes were also similar when patients treated for late recurrence (>24 months after CEA, n ¼ 49) were compared to those treated for early recurrence (24 months after CEA, n ¼ 67). Only when stroke and TIA were combined was a difference observed between the late recurrence (10.0%) and the early recurrence (1.5%) groups ( p ¼ 0.049). Contrary to general opinion, 30-day stroke and stroke + mortality rates from CAS for RS versus PA were not significantly different. Lower neurological event rates were only seen in CAS for early RS compared with late RS after endarterectomy when TIAs were included as an end point in the analysis. CAS for RS must therefore not be considered a low-risk procedure. Technical proficiency for CAS must be equivalent regardless of the etiology of the stenosis. These observations also underscore the need for appropriate patient selection and close follow-up of all patients undergoing CAS.

Research paper thumbnail of Carotid artery closure for endarterectomy does not influence results of angioplasty-stenting for restenosis

Journal of Vascular Surgery, 2002

Objective: Carotid angioplasty and stenting (CAS) has been recommended by some authors for the ma... more Objective: Carotid angioplasty and stenting (CAS) has been recommended by some authors for the management of postendarterectomy restenosis. However, some authors have expressed concern about the influence of primary closure and patch angioplasty performed during carotid endarterectomy (CEA) on the incidence rate of complications after CAS. Methods: We analyzed our consecutive series of 54 CAS procedures performed for restenosis after prior CEA. These procedures accounted for 75% of the 72 CAS procedures performed at our institution for all indications during the last 4 years. Of these 54 patients, 28 (52%) were men and 26 (48%) were women, with a mean age of 69 years. The mean clinical follow-up period was 18 months (range, 1 to 48 months). The mean interval between prior CEA and CAS was 16 months (range, 6 to 62 months). Nineteen patients were symptomatic (35%), and 35 were asymptomatic (65%). The mean severity of restenosis was 84% ± 7% (standard deviation). The mean residual stenosis after CAS was 8% ± 3% (standard deviation). Results: Among the 54 prior CEAs, eight cases were performed with primary closure (15%), five procedures used patch closure with autologous vein (9%), and 41 operations used Dacron patch closures (76%). All patients were managed successfully with CAS with predeployment angioplasty with low profile balloons, self-expanding stents, and poststent angioplasty to approximate the transverse diameter of the carotid artery. No instances of contrast extravasation, arterial disruption, or subintimal dissection were observed. One stroke (1.8%), a retinal infarction with partial field of vision loss, occurred in a patient with prior CEA and Dacron patch closure, and no deaths were observed in the series. Conclusion: Performance of CAS for restenosis after CEA with autologous or synthetic patch angioplasty was technically successful in all 54 procedures. The method of closure of the arteriotomy during CEA, primary closure or patch angioplasty, did not influence the incidence of complications. (J Vasc Surg 2002;35:435-8.)

Research paper thumbnail of Pixel distribution analysis of B-mode ultrasound scan images predicts histologic features of atherosclerotic carotid plaques

Journal of Vascular Surgery, 2002

The correlation of B-mode ultrasonographic morphology with histologic characteristics of atherosc... more The correlation of B-mode ultrasonographic morphology with histologic characteristics of atherosclerotic carotid plaques remains ill-defined. The classification of plaques with recently reported measures of plaque echogenicity and heterogeneity has been unsatisfactory. We used computer-assisted duplex ultrasound (DU) scan image analysis to determine echogenicity of specific tissues in control subjects. This information was used to quantify each tissue in imaged carotid plaques with pixel distribution analysis (PDA). These objective observations then were quantitatively compared with plaque histology in symptomatic and asymptomatic patients. Methods: We performed standardized DU scanning of healthy tissues in 10 volunteer subjects and of 20 carotid artery plaques (7 symptomatic and 13 asymptomatic) in 19 patients with carotid stenosis. The plaques underwent histologic analysis after carotid endarterectomy. The grayscale intensity ranges of blood, lipid, fibromuscular tissue, and calcium were calculated in the control subjects. With computer-assisted image analysis, B-mode images of plaques were linearly scaled to normalize data. Pixel distribution within the images then was analyzed. The grayscale ranges of known tissues obtained from control subjects helped define the amount of intraplaque hemorrhage, lipid, fibromuscular tissue, and calcium within carotid plaque images. This analysis was correlated with tissue composition measurements on histologic sections of excised plaques. Results: The median grayscale intensity (range) in control subjects was 2 (0 to 4) for blood, 12 (8 to 26) for lipid, 53 (41 to 76) for muscle, 172 (112 to 196) for fibrous tissue, and 221 (211 to 255) for calcium. PDA-derived predictions for blood, lipid, fibromuscular tissue, and calcium within carotid plaques correlated significantly with the histologic estimates of each tissue respectively (blood: P ‫؍‬ .012; lipid: P ‫؍‬ .0006; fibromuscular: P ‫؍‬ .035; and calcium: P ‫؍‬ .0001). A significantly higher amount of blood and lipid was seen within symptomatic plaques compared with asymptomatic ones (P ‫؍‬ .0048 and P ‫؍‬ .026, respectively). Conversely, a larger amount of calcification was noted within asymptomatic plaques (P ‫؍‬ .0002). Conclusion: Computer-assisted PDA of DU scan images accurately quantified intraplaque hemorrhage, fibromuscular tissue, calcium, and lipid. Symptomatic plaques had lower calcium content but larger amounts of intraplaque hemorrhage and lipid. Quantitative PDA may be used to determine carotid plaque tissue composition to assist in the identification of symptomatic and potentially unstable asymptomatic plaques. (J Vasc Surg 2002;35:1210-7.)

Research paper thumbnail of In-stent recurrent stenosis after carotid artery stenting: life table analysis and clinical relevance

Journal of Vascular Surgery, 2003

Objectives: Carotid artery stenting has been proposed as an alternative to carotid endarterectomy... more Objectives: Carotid artery stenting has been proposed as an alternative to carotid endarterectomy in cerebral revascularization. Although early results from several centers have been encouraging, concerns remain regarding long-term durability of carotid artery stenting. We report the incidence, characteristics, and management of in-stent recurrent stenosis after long-term follow-up of carotid artery stenting. Methods: Carotid artery stenting (n ‫؍‬ 122) was performed in 118 patients between September 1996 and March 2003. Indications included recurrent stenosis after previous carotid endarterectomy (66%), primary lesions in patients at high-risk (29%), and previous ipsilateral cervical radiation therapy (5%). Fifty-five percent of patients had asymptomatic stenosis; 45% had symptomatic lesions. Each patient was followed up with serial duplex ultrasound scanning. Selective angiography and repeat intervention were performed when duplex ultrasound scans demonstrated 80% or greater in-stent recurrent stenosis. Data were prospectively recorded, and were statistically analyzed with the Kaplan-Meier method and log-rank test. Results: Carotid artery stenting was performed successfully in all cases, with the WallStent or Acculink carotid stent. Thirty-day stroke and death rate was 3.3%, attributable to retinal infarction (n ‫؍‬ 1), hemispheric stroke (n ‫؍‬ 1), and death (n ‫؍‬ 2). Over follow-up of 1 to 74 months (mean, 18.8 months), 22 patients had in-stent recurrent stenosis (40%-59%, n ‫؍‬ 11; 60%-79%, n ‫؍‬ 6; >80%, n ‫؍‬ 5), which occurred within 18 months of carotid artery stenting in 13 patients (60%). None of the patients with in-stent recurrent stenosis exhibited neurologic symptoms. Life table analysis and Kaplan-Meier curves predicted cumulative in-stent recurrent stenosis 80% or greater in 6.4% of patients at 60 months. Three of five in-stent recurrent stenoses occurred within 15 months of carotid artery stenting, and one each occurred at 20 and 47 months, respectively. Repeat angioplasty was performed once in 3 patients and three times in 1 patient, and repeat stenting in 1 patient, without complications. One of these patients demonstrated asymptomatic internal carotid artery occlusion 1 year after repeat intervention. Conclusions: Carotid artery stenting can be performed with a low incidence of periprocedural complications. The cumulative incidence of clinically significant in-stent recurrent stenosis (>80%) over 5 years is low (6.4%). In-stent restenosis was not associated with neurologic symptoms in the 5 patients noted in this cohort. Most instances of in-stent recurrent stenosis occur early after carotid artery stenting, and can be managed successfully with endovascular techniques. (J Vasc Surg 2003;38:1162-9.)

Research paper thumbnail of Technical challenges in a program of carotid artery stenting

Journal of Vascular Surgery, 2004

Objectives: Successful carotid artery stenting (CAS) involves gaining access to the common caroti... more Objectives: Successful carotid artery stenting (CAS) involves gaining access to the common carotid artery, characterizing and crossing the lesion, deploying an anti-embolic device and stent, and retrieving the anti-embolic device. These steps are critical determinants of the complexity of the procedure. The frequency with which technical challenges are encountered during CAS is ill-defined. The purpose of this investigation was to review the incidence and types of technical challenges encountered during CAS and determine their effect on outcome. Methods: Data were prospectively collected for 194 consecutive CAS procedures (177 patients) and separated into group 1, standard CAS technique, and group 2, procedures with technical challenges requiring modifications to the technique. Technical challenges were defined as difficult femoral arterial access (aortoiliac occlusive disease), complex aortic arch anatomy (elongated or bovine arch, deep takeoff of the innominate artery, tandem stenoses (CCA, innominate artery), difficult internal carotid artery anatomy (tortuosity, high-grade stenosis), and circumferential internal carotid artery calcification. The incidence of technical challenges, types of technical modifications required, and effect on outcomes were determined. Results: Fifty technically challenging situations (26%) were encountered in 194 CAS procedures (group 2), which required advanced technical skills. Standard methodols were used in the other 144 procedures (group 1, 74%). No significant differences in 30-day stroke and death rates were noted between the groups (group 1, 3.1%; group 2, 2.0%; P ‫؍‬ .564). Conclusions: Twenty-six percent of the procedures required a modification in the standard technique for successful CAS. Circumferential calcification and severe tortuosity continue to be relative contraindications to CAS. Recognition of these technical challenges and increasing facility with the methods to manage them will enable expanded use of CAS without increased morbidity and mortality. ( J Vasc Surg 2004;40:746-51.)

Research paper thumbnail of Carotid artery stenting: analysis of data for 105 patients at high risk

Journal of Vascular Surgery, 2003

Carotid artery stenting (CAS) has been recommended as an alternative to carotid endarterectomy (C... more Carotid artery stenting (CAS) has been recommended as an alternative to carotid endarterectomy (CEA) by some clinicians. However, recently published clinical trials have reported 30-day stroke and death rates of 10% to 12%. This prompted review of our experience with CAS in patients at high risk, to document our results and guide further use of CAS. From September 1996 to the present, we performed 114 consecutive CAS procedures in 105 patients. Sixty-three patients were men (60%) and 42 patients were women (40%), with mean age of 70 years (range, 45-93 years). Indications for CAS included recurrent stenosis after previous CEA in 74 patients (65%), primary lesions in 32 patients at high risk (28%), and carotid stenosis with previous ipsilateral radiation therapy in 8 patients (7%). Asymptomatic stenosis (>80%) was managed in 70 patients (61%), and symptomatic lesions (>50%) were treated in 44 patients (39%). CAS was technically successful in all patients. Mean severity of stenosis before CAS was 87% +/- 6%, compared with 9% +/- 4% after CAS. Two patients (1.9%) died, 1 of reperfusion-intracerebral hemorrhage and 1 of myocardial infarction 10 days after discharge; and 1 patient (0.95%) had a stroke (retinal infarction), for a 30-day stroke and death rate of 2.85%. Two patients (1.9%) had transient neurologic events. No cranial nerve deficits were noted. No neurologic complications have been noted in the last 27 patients (26%). A 30-day stroke and death rate of 2.85% in our experience demonstrates acceptability of CAS as an alternative to repeat operation or primary CEA in patients at high risk or in patients with radiation-induced stenosis. We recommend further clinical investigation of CAS and participation in clinical trials by vascular surgeons.

Research paper thumbnail of Carotid artery stenting: is there a need to revise ultrasound velocity criteria?

Journal of Vascular Surgery, 2004

Objectives: Ultrasound (US) velocity criteria have not been well-established for patients undergo... more Objectives: Ultrasound (US) velocity criteria have not been well-established for patients undergoing carotid artery stenting (CAS). A potential source of error in using US after CAS is that reduced compliance in the stented artery may result in elevated velocity relative to the native artery. We measured arterial compliance in the stented artery, and developed customized velocity criteria for use early after CAS. Methods: US was performed before and within 3 days after CAS, and after 1 month in a subset of 26 patients. Post-procedural peak systolic velocity (PSV) and end-diastolic velocity (EDV) of the internal carotid artery (ICA), PSV/EDV ratio, and internal carotid artery to common carotid artery ratio (ICA/CCA) were recorded. These were compared with degree of in-stent residual stenosis determined at carotid angiography performed at the completion of CAS. Peterson's elastic modulus (Ep) and compliance (Cp) of the ICA were determined in a subgroup of 20 patients at the distal end of the stent and in the same region in the native ICA before stenting. Results: Ninety CAS procedures were analyzed. Mean (؎SD) angiographic residual stenosis after CAS was 5.4 ؎ 9.1%, whereas corresponding PSV by US was 120.4 ؎ 32.4 cm/s; EDV, 41.4 ؎ 18.6 cm/s; PSV/EDV ratio, 3.3 ؎ 1.2; and ICA/CCA ratio, 1.6 ؎ 0.5. PSV was unchanged at 1 month. Post-CAS PSV and ICA/CCA ratio correlated most with degree of stenosis (P < .0001 for both). Only six patients demonstrated in-stent residual stenosis 20% or greater, but the standard US threshold of PSV 130 cm/s or greater (validated for >20% ICA stenosis in our laboratory) categorized 38 of 90 patients as having stenosis 20% or greater. Receiver operator curve analysis demonstrated that a combined threshold of PSV 150 cm/s or greater and ICA/CCA ratio 2.16 or greater were optimal for detecting residual stenosis of 20% or greater, with sensitivity 100%, specificity 98%, positive predictive value 75%, and negative predictive value 100%. After placement of a stent, the ICA demonstrated significantly increased Ep (1.2 vs 4.4 ؋ 10 3 mm Hg; P ‫؍‬ .004) and decreased Cp (9.8 vs 3.2 %mm Hg ؋ 10 ؊2 ; P ‫؍‬ .0004). Conclusions: Currently accepted US velocity criteria validated in our laboratory for nonstented ICAs falsely classified several stented ICAs with normal diameter on carotid angiograms as having residual in-stent stenosis 20% or greater. We propose a new criterion that defines PSV less than 150 cm/s, with ICA/CCA ratio less than 2.16, as the best correlate to a normal lumen (0%-19% stenosis) in the recently stented ICA. This was associated with increased stiffness of the stented ICA (increased Ep, decreased Cp). These preliminary results suggest that placement of a stent in the carotid artery alters its biomechanical properties, which may cause an increase in US velocity measurements in the absence of a technical error or residual stenotic disease. (J Vasc Surg 2004;39:58-66.)

Research paper thumbnail of Management of Mobile Floating Carotid Plaque Using Carotid Artery Stenting

Journal of Endovascular Therapy, 2003

To present management techniques for dealing with mobile floating carotid plaque (MFCP), which re... more To present management techniques for dealing with mobile floating carotid plaque (MFCP), which represents an indeterminate risk of embolic cerebrovascular events. Two high-risk patients with a history of carotid endarterectomy were diagnosed with MFCP by duplex ultrasound scanning. One patient had a left hemispheric transient ischemic attack while the other was asymptomatic with a moderate stenosis. Both were successfully treated with carotid artery stenting, achieving complete coverage of the MFCP. Their outcomes were uneventful, and sustained patency of the stented arteries has been observed during an event-free survival of 32 and 44 months, respectively. Based upon the unique nature of these lesions and our satisfactory clinical results, we believe that carotid stenting may be a viable option for the treatment of MFCP.

Research paper thumbnail of In-stent Restenosis After Carotid Angioplasty and Stenting: A Challenge for the Vascular Surgeon

European Journal of Vascular and Endovascular Surgery, 2005

Purpose. This study aims to review the incidence of in-stent restenosis (ISR), the factors which ... more Purpose. This study aims to review the incidence of in-stent restenosis (ISR), the factors which determine restenosis, and to evaluate the use of various endovascular techniques for the management of ISR following carotid artery stenting (CAS). Methods. Four hundred and seven patients (334 men, mean age 63 years, range 46-86, median 65 years) were treated with CAS between December 2000 and March 2004. Three hundred and seventy-two (89%) patients had at least one ultrasound evaluation performed 6 months after procedure (range 6-40). Recurrent stenosis O80% detected with duplex ultrasound scans were further evaluated by angiography and treated with repeat endovascular procedure. Results. CAS was performed successfully in all cases with a Carotid WallStent (Boston Scientific) using a cerebral protection device (filter). Perioperative complications included four (0.9%) minor and two (0.4%) major strokes these latter two patients died at 5 and 12 days after the operation. No other deaths occurred. A total of 15 carotid arteries (3.6%) in 14 patients had ISR. All ISR were treated with a repeat endovascular procedure: three balloon angioplasty alone, eight angioplasty and secondary stenting, four angioplasty with cutting balloon. Postsurgical restenosis was confirmed to be the only predictive factor for the development of in-stent restenosis (OR 14.5, 95% CI 2.3-113.4, pZ0.005). Endovascular treatment of ISR achieved technical success without periprocedurale complications and the absence of significant restenosis over a median follow up time of 12.4 months (range 3.5-30.7). Conclusion. Our experience with a large cohort of CAS showed an encouragingly low incidence of ISR (3.6%) and successful treatment by repeat endovascular intervention. We recommend attempting all endovascular possibilities before performing stent removal.

Research paper thumbnail of Comparison of platelet activation in unstable and stable angina pectoris and correlation with coronary angiographic findings

The American Journal of Cardiology, 2000

We sought to investigate the relation between platelet activation and the angiographic evidence o... more We sought to investigate the relation between platelet activation and the angiographic evidence of ruptured plaque in patients presenting with unstable and stable angina pectoris. We prospectively enrolled 25 consecutive patients (5 women and 20 men, mean age 62 +/- 3 years), 17 with unstable angina and 8 with stable angina. Systemic venous blood samples were collected within 4 to 6 hours of admission for flow cytometry analysis. Activation-dependent epitope CD63 and glycoprotein IIb/IIIa on the platelet membrane were assayed. Fibrinogen levels were also measured. All patients with unstable angina underwent cardiac catheterization and had angiographic evidence of ruptured plaque. Of the patients with stable angina, 5 underwent coronary angiography with smooth noncomplex lesions and 3 had negative technetium-99m sestamibi stress tests. Patients with unstable angina were characterized by 39% higher levels of fibrinogen than patients with stable angina (423 +/- 304 vs 304 +/- 51 mg/dl, p = 0.004). The percentage of platelets positive for the activation-dependent epitope CD63 was 5 times higher in patients with unstable than stable angina (14.6 +/- 5.6% vs 2.75 +/- 1.6%, p = 0.0026). They also had a 15% higher expression of their glycoprotein IIb/IIIa (517 +/- 79 vs 449 +/- 50 mean fluorescence intensity, p = 0.038). Thus, this study establishes a direct relation between the morphology of ruptured plaque and platelet activation in patients with unstable angina. This may allow for further risk stratification. Patients with unstable complex lesions had a fivefold higher expression of the platelet activation epitope CD63 than patients with stable angina. Furthermore, they had 15% more glycoprotein IIb/IIIa aggregation sites expressed on their platelet membrane, thus indicating an intense thrombogenic potential.

Research paper thumbnail of The Carotid Revascularization Endarterectomy versus Stenting Trial: Credentialing of Interventionalists and Final Results of Lead-in Phase

Background and Purpose-Carotid artery stenosis causes up to 10% of all ischemic strokes. Carotid ... more Background and Purpose-Carotid artery stenosis causes up to 10% of all ischemic strokes. Carotid endarterectomy (CEA) was introduced as a treatment to prevent stroke in the early 1950s. Carotid stenting (CAS) was introduced as a treatment to prevent stroke in 1994. Methods-The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) is a randomized trial with blinded end point adjudication. Symptomatic and asymptomatic patients were randomized to CAS or CEA. The primary end point was the composite of any stroke, myocardial infarction, or death during the periprocedural period and ipsilateral stroke thereafter, up to 4 years. Results-There was no significant difference in the rates of the primary end point between CAS and CEA (7.2% versus 6.8%; hazard ratio, 1.11; 95% CI, 0.81 to 1.51; Pϭ0.51). Symptomatic status and sex did not modify the treatment effect, but an interaction with age and treatment was detected (Pϭ0.02). Outcomes were slightly better after CAS for patients aged Ͻ70 years and better after CEA for patients aged Ͼ70 years. The periprocedural end point did not differ for CAS and CEA, but there were differences in the components, CAS versus CEA (stroke 4.1% versus 2.3%, Pϭ0.012; and myocardial infarction 1.1% versus 2.3%, Pϭ0.032). Conclusions-In CREST, CAS and CEA had similar short-and longer-term outcomes. During the periprocedural period, there was higher risk of stroke with CAS and higher risk of myocardial infarction with CEA. Clinical Trial Registration-www.clinicaltrials.gov. Unique identifier: NCT00004732. (Stroke. 2010;41[suppl 1]:S31-S34.)

Research paper thumbnail of Plaque morphology directly related to platelet activation in ACS

Curr Control Trials Cardiov M, 2000

A new study provides prospectively established evidence of a direct association between platelet ... more A new study provides prospectively established evidence of a direct association between platelet activation and plaque rupture in patients with unstable angina. Those with angiographically documented complex lesions had significantly greater expression of both the activation-dependent platelet epitope CD63 and glycoprotein IIb/IIIa aggregation sites on the platelet membrane. These factors indicate intense thrombogenic potential and could potentially be used in risk stratification for acute coronary events.

Research paper thumbnail of Plaque morphology directly related to platelet activation in ACS

Current Controlled Trials in Cardiovascular Medicine, 2000

Context A new study provides prospectively established evidence of a direct association between p... more Context A new study provides prospectively established evidence of a direct association between platelet activation and plaque rupture in patients with unstable angina. Those with angiographically documented complex lesions had significantly greater expression of both the activation-dependent platelet epitope CD63 and glycoprotein IIb/IIIa aggregation sites on the platelet membrane. These factors indicate intense thrombogenic potential and could potentially be used in risk stratification for acute coronary events. Significant findings The authors report that patients with unstable angina were characterized by 39% higher levels of fibrinogen than those with stable angina (423 ? 304 versus 304 ? 51 mg/dl, P = 0.004). Compared with patients with stable angina, those with unstable angina had a five-fold higher percentage of platelets positive for activation-dependent CD63 (14.6 ? 5.6% versus 2.75 ? 1.6%, P = 0.0026) and a 15% higher expression of glycoprotein IIa/IIIb (517 ? 79 versus 449 ? 50, P = 0.038). Comments The raised levels of CD63 provide direct evidence of platelet activation and correlate with angiographic evidence of complex ulcerated lesions, the authors write. Moreover, the pathophysiologic findings further support the clinically proven pivotal role of IIa/IIIb inhibitors in the treatment of

Research paper thumbnail of Abstract 4: Angiographic Predictors of Stroke after Carotid Artery Stenting - A Qualitative and Quantitative Analysis of 1070 Patients in the Carotid Revascularization Endarterectomy versus Stenting Trial

Research paper thumbnail of Outcome of Carotid Artery Stenting for Primary versus Restenotic Lesions

Annals of Vascular Surgery, Jan 5, 2009

Carotid artery stenting (CAS) for restenosis (RS) after carotid endarterectomy (CEA) is presumed ... more Carotid artery stenting (CAS) for restenosis (RS) after carotid endarterectomy (CEA) is presumed to have fewer complications than CAS for primary atherosclerotic (PA) lesions. It has been proposed that interventionalists may limit themselves to CAS for RS initially, while they gain additional experience during their learning curve. However, there are few studies objectively comparing the outcomes of the two groups of patients to substantiate this assumption. We analyzed prospectively collected data on CAS performed at our institution from 1996 to April 2006. Complication rates were compared between CAS performed for RS versus PA lesions. Specific end points studied included in-hospital and 30-day stroke and death rates. The incidence of transient ischemic attack (TIA) was also recorded. Patient demographic features (gender, age, hypertension, diabetes mellitus, coronary artery disease, smoking, hypercholesterolemia, and presence of preoperative neurological symptoms) were recorded. A neurologist examined all patients before and after CAS. Patients with previous CAS with in-stent RS and tandem common carotid artery-internal carotid artery or arch ostial stenoses were excluded from this analysis. CAS procedures (n ¼ 217) performed on 210 patients fulfilled inclusion criteria for this study. Indications for CAS included RS (n ¼ 118, 54%) and PA (n ¼ 99, 46%). The two groups were well matched for all demographic features except hypercholesterolemia, which was more common in the PA group. Thirty-day stroke and stroke + death rates for the entire series were 2.8% and 4.1%, respectively. Within this cohort, 30-day stroke and stroke + death rates were not significantly different between the RS (2.5% and 5.1%) and PA (3.0% and 3.0%) groups. Within the RS group, these outcomes were also similar when patients treated for late recurrence (>24 months after CEA, n ¼ 49) were compared to those treated for early recurrence (24 months after CEA, n ¼ 67). Only when stroke and TIA were combined was a difference observed between the late recurrence (10.0%) and the early recurrence (1.5%) groups ( p ¼ 0.049). Contrary to general opinion, 30-day stroke and stroke + mortality rates from CAS for RS versus PA were not significantly different. Lower neurological event rates were only seen in CAS for early RS compared with late RS after endarterectomy when TIAs were included as an end point in the analysis. CAS for RS must therefore not be considered a low-risk procedure. Technical proficiency for CAS must be equivalent regardless of the etiology of the stenosis. These observations also underscore the need for appropriate patient selection and close follow-up of all patients undergoing CAS.

Research paper thumbnail of Abstract 1: Did Carotid Stenting and Endarterectomy Outcomes Change Over Time in the Carotid Revascularization Endarterectomy versus Stenting Trial?

Research paper thumbnail of Temporal Changes in Periprocedural Events in the Carotid Revascularization Endarterectomy Versus Stenting Trial

Stroke; a journal of cerebral circulation, Jan 14, 2015

Post-hoc, we hypothesized that over the recruitment period of the Carotid Revascularization Endar... more Post-hoc, we hypothesized that over the recruitment period of the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST), increasing experience and improved patient selection with carotid stenting, and to a lesser extent, carotid endarterectomy would contribute to lower periprocedural event rates. Three study periods with approximately the same number of patients were defined to span recruitment. Composite and individual rates of periprocedural stroke, myocardial infarction, and death rate were calculated separately by treatment assignment (carotid stenting/carotid endarterectomy). Temporal changes in unadjusted event rates, and rates after adjustment for temporal changes in patient characteristics, were assessed. For patients randomized to carotid stenting, there was no significant temporal change in the unadjusted composite rates that declined from 6.2% in the first period, to 4.9% in the second, and 4.6% in the third (P=0.28). Adjustment for patient characteristic...

Research paper thumbnail of Buddy wire" technique to overcome proximal coronary tortuosity during rotational atherectomy

The Journal of invasive cardiology, 2005

We report a case in which rotational atherectomy was planned for the treatment of a severely calc... more We report a case in which rotational atherectomy was planned for the treatment of a severely calcified obstructive lesion in the middle right coronary artery. Severe proximal vessel tortuosity prevented the advancement of the Rotablator burr. We utilized the "buddy wire" technique, allowing facilitated advancement of the Rotablator and successful atherectomy and stenting. We propose this old technique as an alternative method to allow advancement of the Rotablator burr through tortuous and calcified vessels.

Research paper thumbnail of Comparaison des résultats du stenting carotidien pour les lésions primitives carotidiennes et les lésions de resténose

Annales de Chirurgie Vasculaire, 2009

Le stenting carotidien (SC) pour rest enose (RS) apr es endart eriectomie carotidienne (CEA) est ... more Le stenting carotidien (SC) pour rest enose (RS) apr es endart eriectomie carotidienne (CEA) est pr esum e donner moins de complications que le SC pour l esions d'ath erome primitives (AP). Il a et e propos e que les op erateurs limitent au d ebut de leur exp erience le SC aux l esions de RS. Cependant, peu d' etudes comparant objectivement les r esultats obtenus dans ces deux groupes de patients ont et e publi ees et il n'est pas possible de valider cette hypoth ese. Nous avons analys e des donn ees collect ees prospectivement sur les patients ayant b en efici e d'un SC dans notre etablissement entre 1996 et avril 2006. Les taux de complication ont et e compar es entre les SC r ealis es pour RS et les SC r ealis es pour des l esions d'AP. Les crit eres de jugement sp ecifiques incluaient la mortalit e intra-hospitali ere, les taux d'accidents vasculaires c er ebraux et de mortalit e a 30 jours. L'incidence des accidents isch emiques transitoires a egalement et e analys ee. Les caract eristiques d emographiques des patients (sexe, â ge, hypertension, diab ete, coronaropathie, tabagisme, hypercholest erol emie, et pr esence de symptô mes neurologiques pr eop eratoires) ont et e analys ees. Tous les patients ont et e examin es par un neurologue avant et apr es le SC. Les patients ayant d ej a benefici e d'un SC et pr esentant une RS intra-stent, les patients pr esentant des st enoses en tandem des art eres carotides primitive et interne, ou ceux ayant une st enose ostiale au niveau de la crosse aortique ont et e exclus de cette analyse. Parmi 217 patients ayant b en efici e d'un SC, 210 ont rempli les crit eres d'inclusion pr e-d efinis. Les indications pour la r ealisation d'un SC ont inclus la RS (n ¼ 118, 54%) et l'AP (n ¼ 99, 46%). Les deux groupes etaient similaires pour ce qui concerne les caract eristiques d emographiques a l'exception de l'hypercholest erol emie, qui etait plus fr equente dans le groupe d'AP. Au total, le taux d'AVC et le taux combin e d'AVC + mortalit e a 30 jours etaient respectivement de 2.8% et 4.1%. Le taux d'AVC et le taux combin e d'AVC + mortalit e a 30 jours n' etaient pas significativement diff erents entre les groupes RS (2,5% et 5,1%) et AP (3,0% et 3,0%). Dans le groupe RS, les r esultats etaient similaires entre les patients trait es pour une RS tardive (>24 mois apr es la CEA, n ¼ 49) et ceux trait es pour une RS pr ecoce (24 mois apr es la CEA, n ¼ 67). Il existait une diff erence entre les patients pr esentant une RS tardive (10.0%) et ceux pr esentant une RS pr ecoce (1.5%) ( p ¼ 0.049) uniquement quand AVC et AIT etaient combin es. Contrairement a l'opinion g en eralement admise, les taux d'AVC a 30 jours et d'AVC + mortalit e a 30 jours apr es SC pour RS et pour AP n' etaient pas significativement diff erents. Des taux plus faibles d' ev enements neurologiques ont et e observ es uniquement lorsque le SC etait r ealis e pour RS pr ecoce en comparaison a la RS tardive et quand les AITs etaient inclus comme crit ere de jugement dans l'analyse. Le SC pour RS ne doit donc pas ê tre consid er e comme une proc edure a faible risque. La comp etence technique pour la r ealisation d'un SC doit ê tre equivalente 354 quelque soit l' etiologie de la st enose. Ces observations soulignent egalement la n ecessit e d'une s election rigoureuse et d'un suivi rapproch e des patients ayant b en efici e d'un SC.

Research paper thumbnail of Resultados del tratamiento con stent de las lesiones primarias de la arteria carótida frente a las reestenosis

Anales de Cirugía Vascular, 2009

Se supone que el tratamiento mediante la implantaci on de un stent carot ıdeo (SC) de las reesten... more Se supone que el tratamiento mediante la implantaci on de un stent carot ıdeo (SC) de las reestenosis ocurridas tras una endarterectom ıa carot ıdea (EAC) tiene menos complicaciones que la colocaci on de un SC en lesiones ateroscler oticas primarias (LAP). Se ha propuesto que los intervencionistas podr ıan limitar inicialmente el SC para los casos de reestenosis, mientras adquieren experiencia adicional durante la curva de aprendizaje. Sin embargo, existen pocos estudios que comparen de forma objetiva los resultados de ambos grupos de pacientes para sostener esta afirmaci on. Analizamos los resultados obtenidos de forma prospectiva sobre los SC implantados en nuestro centro desde 1996 hasta abril de 2006. Se compararon las tasas de complicaciones entre la implantaci on de un SC por reestenosis frente a LAP. Los criterios de valoraci on espec ıficos que se estudiaron fueron la tasa de ictus y de mortalidad intrahospitalarias y a los 30 d ıas. Se registr o adem as la incidencia de accidentes isqu emicos transitorios (AIT). Se registraron las caracter ısticas demogr aficas de los pacientes (sexo, edad, hipertensi on arterial, diabetes mellitus, arteriopat ıa coronaria, tabaquismo, hipercolesterolemia y presencia de s ıntomas neurol ogicos preoperatorios). Un neur ologo examin o a todos los pacientes antes y despu es de la implantaci on de un SC. Se excluy o del an alisis a los pacientes con un SC implantado previamente con restenosis intrastent, con estenosis en t andem de las arterias car otida com un e interna, y con lesiones ostiales del cayado a ortico. Cumplieron los criterios de inclusi on de este estudio 217 SC implantados en 210 pacientes. Las indicaciones para la implantaci on de un SC fueron la reestenosis (n ¼ 118, 54%) y la LAP (n ¼ 99, 46%). Las caracter ısticas demogr aficas de ambos grupos eran comparables a excepci on de la hipercolesterolemia, que fue m as frecuente en el grupo de LAP. Las tasas de ictus e ictus y mortalidad a los 30 d ıas de toda la serie fueron del 2,8 y 4,1%, respectivamente. En esta cohorte, las tasas de ictus e ictus m as mortalidad a los 30 d ıas no difirieron de forma significativa entre los grupos de pacientes con reestenosis (2,5 y 5,1%) y LAP (3,0 y 3,0%). En el grupo de pacientes con reestenosis, estos resultados tambi en fueron similares cuando se compar o a los pacientes tratados por una recurrencia tard ıa (> 24 meses tras la EAC, n ¼ 49) con los tratados por una recurrencia precoz ( 24 meses tras la EAC, n ¼ 67). La combinaci on de ictus y AIT fue la unica situaci on en la que se observaron diferencias entre los grupos de pacientes con recurrencia tard ıa (10,0%) y precoz (1,5%) (p ¼ 0,049). En contra de la opini on general, las tasas de ictus e ictus m as mortalidad a los 30 d ıas tras la implantaci on de un SC no difirieron de forma significativa entre los casos de restenosis y LAP. Se observaron unicamente unas tasas de episodios neurol ogicos con la implantaci on de SC en reestenosis precoces menores en comparaci on con las restenosis tard ıas tras EAC, cuando los AIT se incluyeron en el an alisis como criterio de valoraci on. Por tanto, la implantaci on de un SC en los casos de reestenosis no

Research paper thumbnail of Outcome of Carotid Artery Stenting for Primary versus Restenotic Lesions

Annals of Vascular Surgery, 2009

Carotid artery stenting (CAS) for restenosis (RS) after carotid endarterectomy (CEA) is presumed ... more Carotid artery stenting (CAS) for restenosis (RS) after carotid endarterectomy (CEA) is presumed to have fewer complications than CAS for primary atherosclerotic (PA) lesions. It has been proposed that interventionalists may limit themselves to CAS for RS initially, while they gain additional experience during their learning curve. However, there are few studies objectively comparing the outcomes of the two groups of patients to substantiate this assumption. We analyzed prospectively collected data on CAS performed at our institution from 1996 to April 2006. Complication rates were compared between CAS performed for RS versus PA lesions. Specific end points studied included in-hospital and 30-day stroke and death rates. The incidence of transient ischemic attack (TIA) was also recorded. Patient demographic features (gender, age, hypertension, diabetes mellitus, coronary artery disease, smoking, hypercholesterolemia, and presence of preoperative neurological symptoms) were recorded. A neurologist examined all patients before and after CAS. Patients with previous CAS with in-stent RS and tandem common carotid artery-internal carotid artery or arch ostial stenoses were excluded from this analysis. CAS procedures (n ¼ 217) performed on 210 patients fulfilled inclusion criteria for this study. Indications for CAS included RS (n ¼ 118, 54%) and PA (n ¼ 99, 46%). The two groups were well matched for all demographic features except hypercholesterolemia, which was more common in the PA group. Thirty-day stroke and stroke + death rates for the entire series were 2.8% and 4.1%, respectively. Within this cohort, 30-day stroke and stroke + death rates were not significantly different between the RS (2.5% and 5.1%) and PA (3.0% and 3.0%) groups. Within the RS group, these outcomes were also similar when patients treated for late recurrence (>24 months after CEA, n ¼ 49) were compared to those treated for early recurrence (24 months after CEA, n ¼ 67). Only when stroke and TIA were combined was a difference observed between the late recurrence (10.0%) and the early recurrence (1.5%) groups ( p ¼ 0.049). Contrary to general opinion, 30-day stroke and stroke + mortality rates from CAS for RS versus PA were not significantly different. Lower neurological event rates were only seen in CAS for early RS compared with late RS after endarterectomy when TIAs were included as an end point in the analysis. CAS for RS must therefore not be considered a low-risk procedure. Technical proficiency for CAS must be equivalent regardless of the etiology of the stenosis. These observations also underscore the need for appropriate patient selection and close follow-up of all patients undergoing CAS.

Research paper thumbnail of Carotid artery closure for endarterectomy does not influence results of angioplasty-stenting for restenosis

Journal of Vascular Surgery, 2002

Objective: Carotid angioplasty and stenting (CAS) has been recommended by some authors for the ma... more Objective: Carotid angioplasty and stenting (CAS) has been recommended by some authors for the management of postendarterectomy restenosis. However, some authors have expressed concern about the influence of primary closure and patch angioplasty performed during carotid endarterectomy (CEA) on the incidence rate of complications after CAS. Methods: We analyzed our consecutive series of 54 CAS procedures performed for restenosis after prior CEA. These procedures accounted for 75% of the 72 CAS procedures performed at our institution for all indications during the last 4 years. Of these 54 patients, 28 (52%) were men and 26 (48%) were women, with a mean age of 69 years. The mean clinical follow-up period was 18 months (range, 1 to 48 months). The mean interval between prior CEA and CAS was 16 months (range, 6 to 62 months). Nineteen patients were symptomatic (35%), and 35 were asymptomatic (65%). The mean severity of restenosis was 84% ± 7% (standard deviation). The mean residual stenosis after CAS was 8% ± 3% (standard deviation). Results: Among the 54 prior CEAs, eight cases were performed with primary closure (15%), five procedures used patch closure with autologous vein (9%), and 41 operations used Dacron patch closures (76%). All patients were managed successfully with CAS with predeployment angioplasty with low profile balloons, self-expanding stents, and poststent angioplasty to approximate the transverse diameter of the carotid artery. No instances of contrast extravasation, arterial disruption, or subintimal dissection were observed. One stroke (1.8%), a retinal infarction with partial field of vision loss, occurred in a patient with prior CEA and Dacron patch closure, and no deaths were observed in the series. Conclusion: Performance of CAS for restenosis after CEA with autologous or synthetic patch angioplasty was technically successful in all 54 procedures. The method of closure of the arteriotomy during CEA, primary closure or patch angioplasty, did not influence the incidence of complications. (J Vasc Surg 2002;35:435-8.)

Research paper thumbnail of Pixel distribution analysis of B-mode ultrasound scan images predicts histologic features of atherosclerotic carotid plaques

Journal of Vascular Surgery, 2002

The correlation of B-mode ultrasonographic morphology with histologic characteristics of atherosc... more The correlation of B-mode ultrasonographic morphology with histologic characteristics of atherosclerotic carotid plaques remains ill-defined. The classification of plaques with recently reported measures of plaque echogenicity and heterogeneity has been unsatisfactory. We used computer-assisted duplex ultrasound (DU) scan image analysis to determine echogenicity of specific tissues in control subjects. This information was used to quantify each tissue in imaged carotid plaques with pixel distribution analysis (PDA). These objective observations then were quantitatively compared with plaque histology in symptomatic and asymptomatic patients. Methods: We performed standardized DU scanning of healthy tissues in 10 volunteer subjects and of 20 carotid artery plaques (7 symptomatic and 13 asymptomatic) in 19 patients with carotid stenosis. The plaques underwent histologic analysis after carotid endarterectomy. The grayscale intensity ranges of blood, lipid, fibromuscular tissue, and calcium were calculated in the control subjects. With computer-assisted image analysis, B-mode images of plaques were linearly scaled to normalize data. Pixel distribution within the images then was analyzed. The grayscale ranges of known tissues obtained from control subjects helped define the amount of intraplaque hemorrhage, lipid, fibromuscular tissue, and calcium within carotid plaque images. This analysis was correlated with tissue composition measurements on histologic sections of excised plaques. Results: The median grayscale intensity (range) in control subjects was 2 (0 to 4) for blood, 12 (8 to 26) for lipid, 53 (41 to 76) for muscle, 172 (112 to 196) for fibrous tissue, and 221 (211 to 255) for calcium. PDA-derived predictions for blood, lipid, fibromuscular tissue, and calcium within carotid plaques correlated significantly with the histologic estimates of each tissue respectively (blood: P ‫؍‬ .012; lipid: P ‫؍‬ .0006; fibromuscular: P ‫؍‬ .035; and calcium: P ‫؍‬ .0001). A significantly higher amount of blood and lipid was seen within symptomatic plaques compared with asymptomatic ones (P ‫؍‬ .0048 and P ‫؍‬ .026, respectively). Conversely, a larger amount of calcification was noted within asymptomatic plaques (P ‫؍‬ .0002). Conclusion: Computer-assisted PDA of DU scan images accurately quantified intraplaque hemorrhage, fibromuscular tissue, calcium, and lipid. Symptomatic plaques had lower calcium content but larger amounts of intraplaque hemorrhage and lipid. Quantitative PDA may be used to determine carotid plaque tissue composition to assist in the identification of symptomatic and potentially unstable asymptomatic plaques. (J Vasc Surg 2002;35:1210-7.)

Research paper thumbnail of In-stent recurrent stenosis after carotid artery stenting: life table analysis and clinical relevance

Journal of Vascular Surgery, 2003

Objectives: Carotid artery stenting has been proposed as an alternative to carotid endarterectomy... more Objectives: Carotid artery stenting has been proposed as an alternative to carotid endarterectomy in cerebral revascularization. Although early results from several centers have been encouraging, concerns remain regarding long-term durability of carotid artery stenting. We report the incidence, characteristics, and management of in-stent recurrent stenosis after long-term follow-up of carotid artery stenting. Methods: Carotid artery stenting (n ‫؍‬ 122) was performed in 118 patients between September 1996 and March 2003. Indications included recurrent stenosis after previous carotid endarterectomy (66%), primary lesions in patients at high-risk (29%), and previous ipsilateral cervical radiation therapy (5%). Fifty-five percent of patients had asymptomatic stenosis; 45% had symptomatic lesions. Each patient was followed up with serial duplex ultrasound scanning. Selective angiography and repeat intervention were performed when duplex ultrasound scans demonstrated 80% or greater in-stent recurrent stenosis. Data were prospectively recorded, and were statistically analyzed with the Kaplan-Meier method and log-rank test. Results: Carotid artery stenting was performed successfully in all cases, with the WallStent or Acculink carotid stent. Thirty-day stroke and death rate was 3.3%, attributable to retinal infarction (n ‫؍‬ 1), hemispheric stroke (n ‫؍‬ 1), and death (n ‫؍‬ 2). Over follow-up of 1 to 74 months (mean, 18.8 months), 22 patients had in-stent recurrent stenosis (40%-59%, n ‫؍‬ 11; 60%-79%, n ‫؍‬ 6; >80%, n ‫؍‬ 5), which occurred within 18 months of carotid artery stenting in 13 patients (60%). None of the patients with in-stent recurrent stenosis exhibited neurologic symptoms. Life table analysis and Kaplan-Meier curves predicted cumulative in-stent recurrent stenosis 80% or greater in 6.4% of patients at 60 months. Three of five in-stent recurrent stenoses occurred within 15 months of carotid artery stenting, and one each occurred at 20 and 47 months, respectively. Repeat angioplasty was performed once in 3 patients and three times in 1 patient, and repeat stenting in 1 patient, without complications. One of these patients demonstrated asymptomatic internal carotid artery occlusion 1 year after repeat intervention. Conclusions: Carotid artery stenting can be performed with a low incidence of periprocedural complications. The cumulative incidence of clinically significant in-stent recurrent stenosis (>80%) over 5 years is low (6.4%). In-stent restenosis was not associated with neurologic symptoms in the 5 patients noted in this cohort. Most instances of in-stent recurrent stenosis occur early after carotid artery stenting, and can be managed successfully with endovascular techniques. (J Vasc Surg 2003;38:1162-9.)

Research paper thumbnail of Technical challenges in a program of carotid artery stenting

Journal of Vascular Surgery, 2004

Objectives: Successful carotid artery stenting (CAS) involves gaining access to the common caroti... more Objectives: Successful carotid artery stenting (CAS) involves gaining access to the common carotid artery, characterizing and crossing the lesion, deploying an anti-embolic device and stent, and retrieving the anti-embolic device. These steps are critical determinants of the complexity of the procedure. The frequency with which technical challenges are encountered during CAS is ill-defined. The purpose of this investigation was to review the incidence and types of technical challenges encountered during CAS and determine their effect on outcome. Methods: Data were prospectively collected for 194 consecutive CAS procedures (177 patients) and separated into group 1, standard CAS technique, and group 2, procedures with technical challenges requiring modifications to the technique. Technical challenges were defined as difficult femoral arterial access (aortoiliac occlusive disease), complex aortic arch anatomy (elongated or bovine arch, deep takeoff of the innominate artery, tandem stenoses (CCA, innominate artery), difficult internal carotid artery anatomy (tortuosity, high-grade stenosis), and circumferential internal carotid artery calcification. The incidence of technical challenges, types of technical modifications required, and effect on outcomes were determined. Results: Fifty technically challenging situations (26%) were encountered in 194 CAS procedures (group 2), which required advanced technical skills. Standard methodols were used in the other 144 procedures (group 1, 74%). No significant differences in 30-day stroke and death rates were noted between the groups (group 1, 3.1%; group 2, 2.0%; P ‫؍‬ .564). Conclusions: Twenty-six percent of the procedures required a modification in the standard technique for successful CAS. Circumferential calcification and severe tortuosity continue to be relative contraindications to CAS. Recognition of these technical challenges and increasing facility with the methods to manage them will enable expanded use of CAS without increased morbidity and mortality. ( J Vasc Surg 2004;40:746-51.)

Research paper thumbnail of Carotid artery stenting: analysis of data for 105 patients at high risk

Journal of Vascular Surgery, 2003

Carotid artery stenting (CAS) has been recommended as an alternative to carotid endarterectomy (C... more Carotid artery stenting (CAS) has been recommended as an alternative to carotid endarterectomy (CEA) by some clinicians. However, recently published clinical trials have reported 30-day stroke and death rates of 10% to 12%. This prompted review of our experience with CAS in patients at high risk, to document our results and guide further use of CAS. From September 1996 to the present, we performed 114 consecutive CAS procedures in 105 patients. Sixty-three patients were men (60%) and 42 patients were women (40%), with mean age of 70 years (range, 45-93 years). Indications for CAS included recurrent stenosis after previous CEA in 74 patients (65%), primary lesions in 32 patients at high risk (28%), and carotid stenosis with previous ipsilateral radiation therapy in 8 patients (7%). Asymptomatic stenosis (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;80%) was managed in 70 patients (61%), and symptomatic lesions (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;50%) were treated in 44 patients (39%). CAS was technically successful in all patients. Mean severity of stenosis before CAS was 87% +/- 6%, compared with 9% +/- 4% after CAS. Two patients (1.9%) died, 1 of reperfusion-intracerebral hemorrhage and 1 of myocardial infarction 10 days after discharge; and 1 patient (0.95%) had a stroke (retinal infarction), for a 30-day stroke and death rate of 2.85%. Two patients (1.9%) had transient neurologic events. No cranial nerve deficits were noted. No neurologic complications have been noted in the last 27 patients (26%). A 30-day stroke and death rate of 2.85% in our experience demonstrates acceptability of CAS as an alternative to repeat operation or primary CEA in patients at high risk or in patients with radiation-induced stenosis. We recommend further clinical investigation of CAS and participation in clinical trials by vascular surgeons.

Research paper thumbnail of Carotid artery stenting: is there a need to revise ultrasound velocity criteria?

Journal of Vascular Surgery, 2004

Objectives: Ultrasound (US) velocity criteria have not been well-established for patients undergo... more Objectives: Ultrasound (US) velocity criteria have not been well-established for patients undergoing carotid artery stenting (CAS). A potential source of error in using US after CAS is that reduced compliance in the stented artery may result in elevated velocity relative to the native artery. We measured arterial compliance in the stented artery, and developed customized velocity criteria for use early after CAS. Methods: US was performed before and within 3 days after CAS, and after 1 month in a subset of 26 patients. Post-procedural peak systolic velocity (PSV) and end-diastolic velocity (EDV) of the internal carotid artery (ICA), PSV/EDV ratio, and internal carotid artery to common carotid artery ratio (ICA/CCA) were recorded. These were compared with degree of in-stent residual stenosis determined at carotid angiography performed at the completion of CAS. Peterson's elastic modulus (Ep) and compliance (Cp) of the ICA were determined in a subgroup of 20 patients at the distal end of the stent and in the same region in the native ICA before stenting. Results: Ninety CAS procedures were analyzed. Mean (؎SD) angiographic residual stenosis after CAS was 5.4 ؎ 9.1%, whereas corresponding PSV by US was 120.4 ؎ 32.4 cm/s; EDV, 41.4 ؎ 18.6 cm/s; PSV/EDV ratio, 3.3 ؎ 1.2; and ICA/CCA ratio, 1.6 ؎ 0.5. PSV was unchanged at 1 month. Post-CAS PSV and ICA/CCA ratio correlated most with degree of stenosis (P < .0001 for both). Only six patients demonstrated in-stent residual stenosis 20% or greater, but the standard US threshold of PSV 130 cm/s or greater (validated for >20% ICA stenosis in our laboratory) categorized 38 of 90 patients as having stenosis 20% or greater. Receiver operator curve analysis demonstrated that a combined threshold of PSV 150 cm/s or greater and ICA/CCA ratio 2.16 or greater were optimal for detecting residual stenosis of 20% or greater, with sensitivity 100%, specificity 98%, positive predictive value 75%, and negative predictive value 100%. After placement of a stent, the ICA demonstrated significantly increased Ep (1.2 vs 4.4 ؋ 10 3 mm Hg; P ‫؍‬ .004) and decreased Cp (9.8 vs 3.2 %mm Hg ؋ 10 ؊2 ; P ‫؍‬ .0004). Conclusions: Currently accepted US velocity criteria validated in our laboratory for nonstented ICAs falsely classified several stented ICAs with normal diameter on carotid angiograms as having residual in-stent stenosis 20% or greater. We propose a new criterion that defines PSV less than 150 cm/s, with ICA/CCA ratio less than 2.16, as the best correlate to a normal lumen (0%-19% stenosis) in the recently stented ICA. This was associated with increased stiffness of the stented ICA (increased Ep, decreased Cp). These preliminary results suggest that placement of a stent in the carotid artery alters its biomechanical properties, which may cause an increase in US velocity measurements in the absence of a technical error or residual stenotic disease. (J Vasc Surg 2004;39:58-66.)

Research paper thumbnail of Management of Mobile Floating Carotid Plaque Using Carotid Artery Stenting

Journal of Endovascular Therapy, 2003

To present management techniques for dealing with mobile floating carotid plaque (MFCP), which re... more To present management techniques for dealing with mobile floating carotid plaque (MFCP), which represents an indeterminate risk of embolic cerebrovascular events. Two high-risk patients with a history of carotid endarterectomy were diagnosed with MFCP by duplex ultrasound scanning. One patient had a left hemispheric transient ischemic attack while the other was asymptomatic with a moderate stenosis. Both were successfully treated with carotid artery stenting, achieving complete coverage of the MFCP. Their outcomes were uneventful, and sustained patency of the stented arteries has been observed during an event-free survival of 32 and 44 months, respectively. Based upon the unique nature of these lesions and our satisfactory clinical results, we believe that carotid stenting may be a viable option for the treatment of MFCP.

Research paper thumbnail of In-stent Restenosis After Carotid Angioplasty and Stenting: A Challenge for the Vascular Surgeon

European Journal of Vascular and Endovascular Surgery, 2005

Purpose. This study aims to review the incidence of in-stent restenosis (ISR), the factors which ... more Purpose. This study aims to review the incidence of in-stent restenosis (ISR), the factors which determine restenosis, and to evaluate the use of various endovascular techniques for the management of ISR following carotid artery stenting (CAS). Methods. Four hundred and seven patients (334 men, mean age 63 years, range 46-86, median 65 years) were treated with CAS between December 2000 and March 2004. Three hundred and seventy-two (89%) patients had at least one ultrasound evaluation performed 6 months after procedure (range 6-40). Recurrent stenosis O80% detected with duplex ultrasound scans were further evaluated by angiography and treated with repeat endovascular procedure. Results. CAS was performed successfully in all cases with a Carotid WallStent (Boston Scientific) using a cerebral protection device (filter). Perioperative complications included four (0.9%) minor and two (0.4%) major strokes these latter two patients died at 5 and 12 days after the operation. No other deaths occurred. A total of 15 carotid arteries (3.6%) in 14 patients had ISR. All ISR were treated with a repeat endovascular procedure: three balloon angioplasty alone, eight angioplasty and secondary stenting, four angioplasty with cutting balloon. Postsurgical restenosis was confirmed to be the only predictive factor for the development of in-stent restenosis (OR 14.5, 95% CI 2.3-113.4, pZ0.005). Endovascular treatment of ISR achieved technical success without periprocedurale complications and the absence of significant restenosis over a median follow up time of 12.4 months (range 3.5-30.7). Conclusion. Our experience with a large cohort of CAS showed an encouragingly low incidence of ISR (3.6%) and successful treatment by repeat endovascular intervention. We recommend attempting all endovascular possibilities before performing stent removal.

Research paper thumbnail of Comparison of platelet activation in unstable and stable angina pectoris and correlation with coronary angiographic findings

The American Journal of Cardiology, 2000

We sought to investigate the relation between platelet activation and the angiographic evidence o... more We sought to investigate the relation between platelet activation and the angiographic evidence of ruptured plaque in patients presenting with unstable and stable angina pectoris. We prospectively enrolled 25 consecutive patients (5 women and 20 men, mean age 62 +/- 3 years), 17 with unstable angina and 8 with stable angina. Systemic venous blood samples were collected within 4 to 6 hours of admission for flow cytometry analysis. Activation-dependent epitope CD63 and glycoprotein IIb/IIIa on the platelet membrane were assayed. Fibrinogen levels were also measured. All patients with unstable angina underwent cardiac catheterization and had angiographic evidence of ruptured plaque. Of the patients with stable angina, 5 underwent coronary angiography with smooth noncomplex lesions and 3 had negative technetium-99m sestamibi stress tests. Patients with unstable angina were characterized by 39% higher levels of fibrinogen than patients with stable angina (423 +/- 304 vs 304 +/- 51 mg/dl, p = 0.004). The percentage of platelets positive for the activation-dependent epitope CD63 was 5 times higher in patients with unstable than stable angina (14.6 +/- 5.6% vs 2.75 +/- 1.6%, p = 0.0026). They also had a 15% higher expression of their glycoprotein IIb/IIIa (517 +/- 79 vs 449 +/- 50 mean fluorescence intensity, p = 0.038). Thus, this study establishes a direct relation between the morphology of ruptured plaque and platelet activation in patients with unstable angina. This may allow for further risk stratification. Patients with unstable complex lesions had a fivefold higher expression of the platelet activation epitope CD63 than patients with stable angina. Furthermore, they had 15% more glycoprotein IIb/IIIa aggregation sites expressed on their platelet membrane, thus indicating an intense thrombogenic potential.

Research paper thumbnail of The Carotid Revascularization Endarterectomy versus Stenting Trial: Credentialing of Interventionalists and Final Results of Lead-in Phase

Background and Purpose-Carotid artery stenosis causes up to 10% of all ischemic strokes. Carotid ... more Background and Purpose-Carotid artery stenosis causes up to 10% of all ischemic strokes. Carotid endarterectomy (CEA) was introduced as a treatment to prevent stroke in the early 1950s. Carotid stenting (CAS) was introduced as a treatment to prevent stroke in 1994. Methods-The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) is a randomized trial with blinded end point adjudication. Symptomatic and asymptomatic patients were randomized to CAS or CEA. The primary end point was the composite of any stroke, myocardial infarction, or death during the periprocedural period and ipsilateral stroke thereafter, up to 4 years. Results-There was no significant difference in the rates of the primary end point between CAS and CEA (7.2% versus 6.8%; hazard ratio, 1.11; 95% CI, 0.81 to 1.51; Pϭ0.51). Symptomatic status and sex did not modify the treatment effect, but an interaction with age and treatment was detected (Pϭ0.02). Outcomes were slightly better after CAS for patients aged Ͻ70 years and better after CEA for patients aged Ͼ70 years. The periprocedural end point did not differ for CAS and CEA, but there were differences in the components, CAS versus CEA (stroke 4.1% versus 2.3%, Pϭ0.012; and myocardial infarction 1.1% versus 2.3%, Pϭ0.032). Conclusions-In CREST, CAS and CEA had similar short-and longer-term outcomes. During the periprocedural period, there was higher risk of stroke with CAS and higher risk of myocardial infarction with CEA. Clinical Trial Registration-www.clinicaltrials.gov. Unique identifier: NCT00004732. (Stroke. 2010;41[suppl 1]:S31-S34.)

Research paper thumbnail of Plaque morphology directly related to platelet activation in ACS

Curr Control Trials Cardiov M, 2000

A new study provides prospectively established evidence of a direct association between platelet ... more A new study provides prospectively established evidence of a direct association between platelet activation and plaque rupture in patients with unstable angina. Those with angiographically documented complex lesions had significantly greater expression of both the activation-dependent platelet epitope CD63 and glycoprotein IIb/IIIa aggregation sites on the platelet membrane. These factors indicate intense thrombogenic potential and could potentially be used in risk stratification for acute coronary events.