Ipsilateral Ischemic Events Research Articles

Morphological changes of the internal carotid artery: prevalence and characteristics. A clinical and ultrasonographic study in a series of 19 804 patients over 25 years old.

Morphological changes of the internal carotid arteries (McICA) are frequently found during cervical ultrasound studies. However, the etiology of McICA remains controversial. During this study, the prevalence and demographic characteristics of McICA, such as kinking, coiling or looping identified by Doppler ultrasound, were analysed and its relationship with vascular risk factors and stroke was assessed. A retrospective study was performed by analysing 19 804 patients who were subjected to cervical ultrasonographic study between January 2000 and June 2012. The data were statistically analysed with SPSS® 20 and a multivariate logistic regression was performed. Statistical significance was accepted for P < 0.05 and 95% confidence intervals (CIs) were used. Morphological changes of the internal carotid arteries were present in 2678 patients (13.5%) and were unilateral in 61.6% of these cases. Carotid kinking was found in 80% of the patients, coiling in 16% and looping in 1%. In multivariate analysis, the presence of McICA was related to older groups (1.04; 95% CI, 1.04-1.05; P < 0.01), female gender (1.78; 95% CI, 1.64-1.94; P < 0.01), patients with hyperlipidemia (1.28; 95% CI, 1.17-1.40; P < 0.01), carotid thickness (1.22; 95% CI, 1.13-1.33; P < 0.01) and cardiac or cardioembolic disease (1.11; 95% CI, 1.01-1.21; P = 0.02). The results of this study indicate that kinking in the carotid artery was associated with ipsilateral cerebral ischemic events (1.43; 95% CI, 1.040-1.958; P < 0.05). Morphological changes of the internal carotid arteries were associated with aging, female gender and patients with hyperlipidemia, hypertension, diabetes and heart disease. Kinking was associated with ipsilateral cerebral ischemia.

Apport de l’échographie de contraste dans la caractérisation des lésions carotidiennes

Harmonic mode ultrasound with injection of a contrast enhancement agent allows visualization of mobile microbubbles in the carotid plaque corresponding to neovessels secondary to an inflammation or hypoxia. These neovessels could be considered "precursor" markers of the vulnerable plaque. The aim of this work was to give an update on ultrasound contrast imaging acquisition in the exploration of carotid artery both for atheromatous lesions and for large vessel vasculitis. A precise description of the material to be used, the image acquisition methodology and the environmental conditions is discussed, emphasizing the pitfalls to be avoided as well as proper image interpretation. Microbubbles in a plaque are significantly associated with an increase in cardiovascular events (infarction and acute coronary syndrome) and ipsilateral cerebral ischemic events. Wall irregularities, microfissures and ulcer plaque detection are facilitated by the use of contrast compared to the CT scan. No studies have yet validated contrast enhanced ultrasound in the exploration of asymptomatic carotid stenosis. Contrast enhanced ultrasound also allows to detect vasculitis of the large vessels active phases by the presence of microbubbles in the carotid wall thickening and to monitor the regression under appropriate medical treatment. Future validation studies or even registries are needed to allow better use of this tool in everyday clinical practice.

The risk of ischemic events increased in patients with asymptomatic carotid stenosis with decreased cerebrovascular reserve

Identifying high-risk patients with asymptomatic carotid stenosis (ACS) is necessary regardless of whether intensive medical therapy or aggressive treatment is applied. In order to assess the relationship between cerebrovascular reserve...

A comparison of results of carotid endarterectomy in octogenarians and nonagenarians to younger patients from the Mid-America Vascular Study Group and the Society for Vascular Surgery Vascular Quality Initiative

ObjectiveCarotid endarterectomy (CEA) reduces stroke risk in selected patients. However, CEA risk profile may be different in older patients. We compared characteristics and outcomes of octogenarians and nonagenarians with those of younger patients. MethodsDeidentified data from CEA patients were obtained from the Society for Vascular Surgery Vascular Quality Initiative (VQI) database. Prior CEA, carotid artery stent, or combined CEA and coronary artery bypass were excluded, yielding 7390 CEAs in octogenarians and nonagenarians (≥80 years of age) and 35,303 CEAs in younger patients (<80 years of age). We compared post-CEA outcomes, including periprocedural cerebral ischemic events and death, and details such as operative time, bleeding, and return to surgery. ResultsOctogenarians and nonagenarians were more likely to have pre-CEA neurologic symptoms (51.4% vs 45.6%; P < .001) and to have never smoked (37.8% vs 22.0%; P < .001), and they were slightly more likely to have required urgent CEA (16.1% vs 13.4%; P < .001). Stenosis ≥70% was similar (octogenarians and nonagenarians, 94.2%; younger patients, 94.4%; P = .45). Perioperative ipsilateral neurologic events and ipsilateral stroke were slightly more common among octogenarians and nonagenarians (1.6% vs 1.1% [P < .001] and 1.2% vs 0.8% [P = .002]). Multivariate modeling (logistic regression) showed that pre-CEA neurologic symptoms (odds ratios, 1.35 [P = .005] and 1.42 [P = .007]), pre-CEA ipsilateral cortical ischemic event (odds ratios, 1.18 [P < .001] and 1.20 [P < .001]), and urgency (odds ratios, 1.75 [P < .001] and 1.67 [P < .001]) remained strong predictors of any ipsilateral neurologic event and any ipsilateral stroke, respectively. However, age ≥80 years remained a significant predictor of these outcomes (odds ratios, 1.37 [P = .003] and 1.44 [P = .004]). Kaplan-Meier estimated survival was lower for octogenarians and nonagenarians at 30 days and 1 year (98.6% vs 99.4% and 93.7% vs 97.0%; log-rank, P < .001). Age ≥80 years was also associated with a greater rate of discharge to other than home after CEA, a difference that was only partially explained by comorbidities in multivariate modeling. ConclusionsCEA was performed with low rates of perioperative neurologic events and mortality. Multivariate testing showed that the higher rate of neurologic complications in octogenarians and nonagenarians appeared partially related to symptomatic status and urgent surgery; but after adjusting for these factors, age ≥80 years still predicted a slightly higher rate. Periprocedural CEA outcomes appear similar in comparing older and younger patients, although longer term survival is lower for older patients, and older patients are at greater risk of discharge to other than home. CEA was associated with slightly higher risk of neurologic complications in older patients but may be considered appropriate for selected octogenarians and nonagenarians.

Innovations in Endovascular Treatment Strategies for Large Carotid Cavernous Aneurysms—The Safety and Efficacy of a Flow Diverter

The efficacy for the treatment of large carotid cavernous aneurysms (CCAs) was compared between conventional endovascular treatments, stent-assisted coiling (SAC), parent artery occlusion (PAO), and the flow diverter (FD). Between January 2001 and December 2015, 49 patients with large, broad-necked, unruptured CCA underwent endovascular treatment at our institution. We performed PAO in 22 patients, SAC in 18 patients, and FD in 9 patients. Safety and efficacy were assessed in all patients by periodic clinical and radiological examinations during a 6-month follow-up. All 22 aneurysms treated with PAO disappeared immediately after treatment, but in the SAC-treated group, complete occlusion was obtained in only 5 of the 18 patients. All aneurysms in the FD group resulted in body filling. Perioperative ipsilateral temporary ischemic events occurred in 6 cases (PAO 4, SAC 2, FD 0). Delayed deterioration or new onset of cranial nerve symptoms was observed in 10 cases (PAO 3, SAC 3, FD 4), almost all of which recovered within 3 months. During the 6-month follow-up, all aneurysms treated with PAO showed a decrease in size without recanalization. In the SAC group, 12 aneurysms showed neck remnants, and marked recanalization occurred in 4 cases. Six of the 9 aneurysms in the FD group were completely occluded. The FD provided excellent final results despite transient worsening of symptoms. Although further long-term follow-up is essential, from a cost-effective and time-saving viewpoint, FD is a relatively safe and reliable method for the treatment of large CCAs.

Mid- and long-term follow-up of revascularization and stenting of nonacute intracranial vertebrobasilar artery occlusion

Objective To evaluate the mid- and long-term follow-up outcome of revascularization and stenting of nonacute intracranial vertebrobasilar artery occlusion. Methods Consecutive data of 27 patients who suffered from nonacute intracranial vertebrobasilar artery occlusion beyond 24 hours and underwent endovascular revascularization, were retrospectively collected and analyzed. Complications and recurrent ischemic events during the follow-up period were recorded. The modified Rankin scale (mRS) scores were used and compared between pre- and postoperation. Results All 27 patients except one (96.3%) obtained successful recanalization. After the procedure, 13 patients showed improvement, 11 were stable, and 3 worse. The decline of median mRS scores, which was 4 (interquarter range-IR, 2- 5) preoperatively and 3 (IR, 1- 5) on discharge. Five patients suffered from procedural complications and three of them resulted in aggravation. Nineteen patients received imaging follow-up during the median 10 months, 6 restenosis occurred and 3 of them were symptomatic. During median 55 months clinical follow-up after operation, 2 ipsilateral stroke and 2 ipsilateral transient ischemic attack occurred. The mRS scores decreased significantly in the first one year after procedure. Conclusions Revascularization and stenting of nonacute intracranial vertebrobasilar artery occlusion can prevent recurrent ipsilateral ischemic event and improve disability recovery in the first one year. Key words: Arterial occlusive diseases; Vertebrobasilar insufficiency; Radiology, interventional; Nonacute

Impaired Cerebrovascular Reactivity Predicts Recurrent Symptoms in Patients with Carotid Artery Occlusion: A Hypercapnia BOLD fMRI Study.

A key factor in predicting recurrent ischemic episodes in patients with carotid artery occlusion is the presence of hemodynamic impairment. There is, however, no consensus on how to best assess this risk in terms of imaging modalities or thresholds used. Here we investigated whether a predefined threshold of hemispheric asymmetry in hypercapnia fMRI predicts recurrent symptoms in patients with carotid artery occlusion. We studied 23 patients (2 women) with a mean age of 67.5 ± 9 years. Patients were assessed for recurrent ischemic events until lost to follow-up, study end, death, or recurrent ischemic event. Hypercapnia fMRI was used to assess the cerebrovascular reserve and quantify the percentage signal change in GM in the MCA territory and the hemispheric asymmetry index. Kaplan-Meier survival analysis and log-rank tests were performed to assess differences between patients with normal or abnormal hemispheric indices. The median follow-up was 20 months. During this period, 8 patients experienced recurrent events, and 15 did not. The percentage signal change in GM in the MCA territory was significantly decreased in those patients with recurrent events compared with those without (2.39 ± 0.22 versus 2.70 ± 0.42, P = .032). The normal hemispheric index predicted event-free survival during follow-up (median, 20 months) for both the combined outcome (recurrent events and/or death, log-rank, P = .034) and recurrent retinal or ipsilateral ischemic events only (log-rank, P = .012). The hemispheric asymmetry index derived from hypercapnia fMRI showed hemodynamic impairment in more than half of the studied patients with carotid occlusion, and those patients showed a higher risk of recurrent ischemic symptoms.

Abstract TP232: Symptomatic Plaque with Low-grade Stenosis Which Retains Hyperintensity After an Ischemic Event may Indicate a High Risk of a Subsequent Ipsilateral Ischemic Event

Introduction: Intraplaque hemorrhage (IPH) has been reported to be a characteristic feature of a vulnerable plaque, indicated by an area of high signal intensity on carotid MRI. It has been reported that symptomatic low-grade stenosis with IPH is strongly associated with ischemic events, but there are limited data regarding the dynamics of the carotid plaque signal. The aim of this study was to assess the time-dependent change of carotid plaque in the symptomatic patient with low-grade stenosis. Methods: Thirty-eight symptomatic patients with carotid low-grade stenosis (0.31 between time points was considered significant. We then investigated changes in rSI and subsequent ipsilateral ischemic events. Result: Of the 38 patients, there were strong-positive and positive plaque at baseline in 22 and 12 patients, respectively. During a mean follow-up period of 42.5 months, 26 positive plaques (74%) at baseline kept an rSI of &gt;1.25, and all of 4 negative plaques at baseline changed positive. Strong-positive plaques at baseline showed a lower tendency to be negative than positive plaque (p=0.08). Twenty-one of the 38 patients (55%) experienced a total of 26 recurrent ischemic events. In patients who experienced recurrent ischemic events, 19 plaques (73%) were strong-positive and 5 plaques (19%) were positive. Compared to the most recent carotid MRI, rSI at the event was stable in 18 patients (69%) and increased in 8 patients (31%). Conclusions: Most symptomatic plaque with low-grade stenosis retained its hyperintensity after ischemic events and had a high rate of subsequent ipsilateral ischemic events. A sustaining high signal intensity might be associated with an increased risk of subsequent ischemic events. Follow-up observation by carotid MRI has the potential to increase the accuracy of stroke risk stratification in the management of carotid low-grade stenosis.

Recurrent stroke in symptomatic carotid stenosis awaiting revascularization: A pooled analysis.

We aimed to quantify the risk and predictors of ipsilateral ischemic stroke in patients with symptomatic carotid stenosis awaiting revascularization (carotid endarterectomy [CEA] or carotid artery stenting) by pooling individual patient data from recent prospective studies with high rates of treatment with modern stroke prevention medications. Data were included from 2 prospective hospital-based registries (Umeå, Barcelona) and one prospective population-based study (Dublin). Patients with symptomatic 50%-99% carotid stenosis eligible for carotid revascularization were included and followed for early recurrent ipsilateral stroke or retinal artery occlusion (RAO). Of 607 patients with symptomatic 50%-99% carotid stenosis, 377 met prespecified inclusion criteria. Ipsilateral recurrent ischemic stroke/RAO risk pre-revascularization was 2.7% (1 day), 5.3% (3 days), 11.5% (14 days), and 18.8% (90 days). On bivariate analysis, presentation with a cerebral vs ocular event was associated with higher recurrent stroke risk (log-rank p = 0.04). On multivariable Cox regression, recurrence was associated with older age (adjusted hazard ratio [HR] per 10-year increase 1.5, p = 0.02) with a strong trend for association with cerebral (stroke/TIA) vs ocular symptoms (adjusted HR 2.7, p = 0.06), but not degree of stenosis, smoking, vascular risk factors, or medications. We found high risk of recurrent ipsilateral ischemic events within the 14-day time period currently recommended for CEA. Randomized trials are needed to determine the benefits and safety of urgent vs subacute carotid revascularization within 14 days after symptom onset.

Carotid Endarterectomy Is Safe, Effective, and Durable, but Can We Make It Better?

The first known carotid endarterectomy (CEA) was likely performed by Dr. Michael DeBakey in 1953. Since that time, the operation has gained widespread approval because it not only effectively reduces the rate of ischemic stroke but also has a relatively low rate of complications. Both the North American Symptomatic Carotid Endarterectomy Trial (NASCET) 1 and the Endarterectomy for Asymptomatic Carotid Artery Stenosis (ACAS) trial 2 demonstrated a significant benefit of endarterectomy over medical therapy alone. Both trials showed durable results with reduced rates of stroke at least 5 years after the operation. The article by Rong et al. recently published in WORLD NEUROSURGERY, “Risk Factors Associated with Ipsilateral Ischemic Events Following Carotid Endarterectomy for Carotid Artery Stenosis,” continues to add to the body of literature demonstrating the efficacy, safety, and durability of CEA. In their study cohort of more than 240 patients with a mean follow-up of more than 50 months, the 5-year risk of ischemic symptom recurrence was approximately 10%. When the authors identified risk factors associated with new ipsilateral ischemic events in these patients, they found that cigarette-smoking, family history of stroke, and atrial fibrillation were all associated with a greater risk of new ischemic events after CEA. Interestingly, symptomatic carotid stenosis was not significantly associated with new ischemic events, although there was a trend toward significance. Only one-third of the ischemic events happened within 30 days of the operation.

Risk Factors Associated with Ipsilateral Ischemic Events Following Carotid Endarterectomy for Carotid Artery Stenosis

Patients undergoing carotid endarterectomy (CEA) are at risk of developing ipsilateral stroke or transient ischemic attacks (TIAs). In this study, we explored factors associated with development of these events following CEA in patients with long-term follow-up. We performed a retrospective analysis of all neurosurgical patients who underwent CEA and presented with ipsilateral ischemic stroke, TIA, or amaurosis fugax. Factors were compared against the outcome variable in univariate analysis. Multivariate logistic regression model was used to identify independent predictive variables. We used Kaplan-Meier analysis (log-rank test) to compare the effect of variables on long-term event-free survival. Our study included 270 patients with an average age of 67.2 years. Two-hundred and forty-nine patients within our study cohort (92.2%) with 273 CEAs were followed at our institution. At presentation, 187 patients (68.5%) were symptomatic. The average follow-up was 50.2 months (113.2 lesion-years). Event-free survival was 91.6% and 89.9% at 2 years and 5 years, respectively. Family history of stroke (P= 0.002), cigarette smoking (P= 0.021), and atrial fibrillation (P= 0.005) significantly increased the risk of adverse events, whereas symptomatic presentation demonstrated a trend toward significance (P= 0.057). A higher risk for ischemic events was observed in female patients as compared with males with asymptomatic presentation (P= 0.005). Our data suggest that family history of stroke, cigarette smoking, and atrial fibrillation are independent risk factors for developing ischemic events after CEA. In patients with asymptomatic presentation, female gender is also a risk factor. Identification of patients at risk is critical for tailored postoperative patient management and patient education.

Associations between Cerebral Embolism and Carotid Intraplaque Hemorrhage during Protected Carotid Artery Stenting.

Carotid artery stent placement in patients with intraplaque hemorrhage remains controversial because of the incidence of cerebral embolism after the procedure. The purpose of this study is to determine if intraplaque hemorrhage is a significant risk factor for cerebral embolism during carotid artery stent placement. This prospective study assessed 94 consecutive patients with severe carotid stenosis. These patients underwent preprocedural carotid MR imaging and postprocedural DWI after carotid artery stent placement. Intraplaque hemorrhage was defined as the presence of high signal intensity within the carotid plaque that was >200% of the signal from the adjacent muscle on MPRAGE. We then analyzed the incidence of postprocedural ipsilateral ischemic events on DWI and primary outcomes within 30 days of carotid artery stent placement. Forty-three patients (45.7%) had intraplaque hemorrhage on an MPRAGE image. There was no significant difference in the incidence of postprocedural ipsilateral ischemic events and primary outcomes between the intraplaque hemorrhage and non-intraplaque hemorrhage group. However, postprocedural ipsilateral ischemic events were more frequently observed in the symptomatic group (17/41 [41.5%]) than in the asymptomatic group (8/53 [15.1%]; P = .005). Intraplaque hemorrhage was not a significant risk factor for cerebral embolism during carotid artery stent placement in patients with severe carotid stenosis. Symptomatic patients should receive more careful treatment during carotid artery stent placement because of the higher risk of postprocedural ipsilateral ischemic events.

Clinical Outcomes of Carotid Endarterectomy in Symptomatic and Asymptomatic Patients with Ipsilateral Intracranial Stenosis.

The risk of perioperative stroke and the benefits of carotid endarterectomy (CEA) remain uncertain in the case of an ipsilateral intracranial stenosis. The aim of this observational study was to analyze the early and late outcomes of CEA in patients with a carotid tandem lesion (CTL), defined as a severe stenosis at the bifurcation with any concomitant lesion ≥50 % involving the intracranial portion of the ipsilateral internal carotid artery or the main trunk of the anterior or middle cerebral artery. From 2000 to 2009, 1143 patients underwent CEA for symptomatic or asymptomatic extracranial carotid stenosis according to the NASCET and ACAS recommendations, respectively. CTLs were diagnosed in 219 patients (19.2 %) by extracranial and transcranial color-coded Doppler sonography combined with noninvasive brain imaging studies. The primary endpoints of the study were perioperative (30-day) stroke and death, and any ipsilateral ischemic adverse events during the follow-up, which ranged from 0.1 to 10 years (mean 4.9 ± 3.3 years). The rates of the primary endpoints were compared between patients with (group I) and without CTL (group II). Overall, 219 CEAs were performed in group I and 924 in group II. Nearly two in three of the carotid lesions (777 of 1143, 68 %) were symptomatic at presentation (62.1 % in group I vs 69.4 % in group II; p = 0.03), with a 23.8 % rate of stroke (21.9 % in group I vs 24.2 % in group II; p = 0.85). There were 2 (0.9 %) perioperative ipsilateral strokes in group I and 5 (0.5 %) in group II (p = 0.62), and no deaths. The 5-year ipsilateral stroke-free, any stroke-free, and overall survival rates did not differ significantly between patients with and without CTL. This study has shown that patients with and without CTL who underwent CEA had a similar occurrence of perioperative adverse events (probably due to the extremely low incidence of perioperative complications) and comparable late outcomes, suggesting that the presence of CTL does not justify refusing CEA for patients who could benefit from it.

不安定プラークを伴った症候性軽度狭窄症に対する抗血小板療法と内膜剝離術

The purpose of this study is to clarify the therapeutic outcomes for symptomatic lowgrade carotid stenosis with vulnerable plaque. We investigated 43 patients with symptomatic lowgrade stenosis (<50%) and a high-signal plaque on T1-weighted imaging. Single antiplatelet therapy (APT) was started, and recurrent ischemic events were treated with dual APT. Carotid endarterectomy (CEA) was considered when recurrence occurred refractory to dual APT. During follow-up (mean, 28.1 ± 23.5 months), 23 of 43 patients (53%) experienced recurrent events. Fifteen of the 26 patients who underwent dual APT had recurrent events. Fourteen patients were treated with CEA, and the complication seen was temporary hoarseness. During postoperative follow-up (mean, 24.8 ± 17.6 months), no patients showed ipsilateral ischemic events. We concluded that symptomatic low-grade carotid stenosis with a high-signal plaque on carotid magnetic resonance imaging tends to be associated with a high risk of recurrent ischemic events, even with dual APT. CEA for symptomatic lowgrade carotid stenosis might be safe and effective.

CT angiographic features of symptom-producing plaque in moderate-grade carotid artery stenosis.

Emerging evidence indicates that plaque imaging can improve stroke risk stratification in patients with carotid artery atherosclerosis. We studied the association between soft and hard (calcified) plaque thickness measurements on CTA and symptomatic disease status (ipsilateral stroke or TIA) in patients with moderate-grade carotid artery stenosis. We measured soft-plaque and hard-plaque thickness on CTA axial source images in each carotid artery plaque in subjects with NASCET 50%-69% ICA stenosis. We used logistic regression and receiver operating characteristic analyses to assess the strength of the association between thickness measurements and prior stroke or TIA. Twenty of 72 vessels studied (27.7%) had ischemic symptoms ipsilateral to the side of moderate-grade carotid stenosis. Each 1-mm increase in soft plaque resulted in a 3.7 times greater odds of a prior ipsilateral ischemic event (95% CI, 1.9-7.2). Conversely, for each 1-mm increase in hard plaque, the odds of being symptomatic decreased by approximately 80% (OR, 0.22; 95% CI, 0.10%-0.48%). Receiver operating characteristic analysis showed an area under the curve of 0.88 by using soft-plaque thickness measurements to discriminate between asymptomatic and symptomatic plaques. Sensitivity and specificity were optimized by using a maximum soft-plaque thickness of 2.2 mm, which provided a sensitivity of 85% and a specificity of 83%. Simple CTA plaque-thickness measurements might differentiate symptomatic and asymptomatic moderate-grade carotid artery plaque. With further prospective validation, CTA plaque measures could function as an easily implementable tool for risk stratification in carotid artery disease.

Carotid endarterectomy for asymptomatic carotid stenosis in the very elderly

The indication for carotid endarterectomy (CEA) is uncertain in patients with asymptomatic severe (≥60% luminal narrowing according to the North American Symptomatic Carotid Endarterectomy Trial criteria) carotid stenosis (ASCS), especially in the very elderly, because current evidence suggests that the risk of future stroke has been dropping in the past two decades owing to the recent advances in medical therapy. The aim of this observational study was to compare early and late outcomes in patients ≥80 years old with ASCS treated with CEA plus best medical treatment (BMT) or with BMT alone. From 2005 to 2012, 69 octogenarians with ASCS underwent CEA plus BMT (group 1), and another 54 received BMT alone (group 2). All operations were eversion CEAs. BMT included lipid-lowering drugs, new antiplatelet and antihypertensive agents, avoidance of smoking, careful blood pressure and glycemic control, and lifestyle changes. Follow-up with serial ultrasonographic examination was obtained in 118 patients for a median 4.4-year period. There were no perioperative (30-day) strokes or deaths and one transient ischemic attack (1.4%). One late minor stroke developed in a CEA patient (1.5%). No late restenoses or occlusions were detected. Five patients in group 2 (9.6%) became symptomatic (one transient ischemic attack and four minor strokes) and subsequently underwent successful CEA; all their carotid plaques were complicated by ulceration and intraplaque hemorrhage (with plaque progression in four cases), confirmed by computed tomography images. The rate of freedom from cerebral ischemic events at 5 years showed a significant benefit for elderly patients who had CEA vis-à-vis those who did not (98% vs 84%; P = .04), and so did the 5-year rate of freedom from ipsilateral carotid disease progression (100% vs 91%; P = .01). At 5 years, the mortality rate was comparable for elderly patients whether they had CEA or not (66% vs 68%; P = .65). CEA is a safe, effective, and durable treatment for ASCS in patients aged 80 years or more, carrying an insignificant perioperative stroke/death risk. CEA associated with BMT seems preferable to BMT alone in preventing the risk of ipsilateral ischemic events, without translating into a longer survival.

Progression Rate and Ipsilateral Neurological Events in Asymptomatic Carotid Stenosis

Background and Purpose—Progression of asymptomatic carotid stenoses with >50% luminal narrowing is associated with an increased risk of stroke. The significance of the progression rate in these patients is unknown. The main aim of this study was to evaluate the rate of change of carotid luminal narrowing over 1 year, as a risk factor for ipsilateral ischemic events, in patients with a >50% asymptomatic carotid stenosis. Secondary aims were to establish the incidence of changes in carotid luminal narrowing and establish additional risk factors for ipsilateral neurological events. Methods—A retrospective analysis was conducted of data derived from the deferred endarterectomy arm of the Asymptomatic Carotid Surgery Trial. Patients were followed up for ≥5 years with serial carotid duplex examinations. Data were derived from information obtained at randomization and annual follow-up visits with carotid duplex examination. Potential risk factors for ipsilateral neurological events were analyzed in Poisson regre...

Abstract W MP67: Etiology-Specific Clinical and Imaging Features in Ischemic Stroke

Background: Identification of clinical and imaging characteristics of ischemic stroke that can predict the underlying etiology is critical for accurate stroke subtyping. We sought to investigate the relationship between stroke characteristics and stroke etiology in 7,591 patients in the NINDS Stroke Genetics Network Study. Methods: We determined the probability of having a major etiology in the presence of certain stroke characteristics that were previously linked to specific stroke mechanisms. We excluded patients with multiple competing major etiologies. All patients had brain imaging, intra- and extra-cranial vascular imaging, and complete cardiac assessment. We defined major etiologies according to the Causative Classification of Stroke System Criteria without reference to the stroke characteristics under study. Results: History of 1 ipsilateral ischemic events within the last month, the presence of internal watershed infarcts or multiple, ipsilateral, unilateral, and temporally separate infarcts were associated with large artery atherosclerosis (Table). Multiple acute infarcts in different cerebral circulations were more common in patients with major cardiac source of embolism as well as in those with uncommon/cryptogenic causes. Stereotypic lacunar TIAs within the last week and lacunar syndrome were associated with lacunar infarction Discussion: Clinical and imaging stroke characteristics appear to predict stroke etiologies. This information may find utility in developing algorithms for a guided stroke evaluation as well as help identify the most likely causative etiology in the presence of multiple competing etiologies.

Intraplaque High-Intensity Signal on 3D Time-of-Flight MR Angiography Is Strongly Associated with Symptomatic Carotid Artery Stenosis

Intraplaque hemorrhage in carotid artery atherosclerotic plaque has been shown to be a marker of risk, associated with prior and future ischemic events, and has been associated with regions of intraplaque high-intensity signal on 3D-TOF MRA. We assessed the association of intraplaque high-intensity signal determined on 3D-TOF MRA with the incidence of prior ipsilateral stroke or TIA. We assessed intraplaque hemorrhage by evaluating for intraplaque high-intensity signal adapting a recently validated technique on 3D-TOF source images in participants with high-grade (≥ 70%) extracranial carotid stenosis. Logistic regression analyses were used to assess the strength of association between the presence of intraplaque high-intensity signal on routine MRA sequences and prior stroke or TIA. Intraplaque high-intensity signal was present in 22 (41.5%) of 53 carotid arteries studied in 51 patients. Ipsilateral ischemic events occurred in 15 (68.1%) of 22 in the intraplaque high-intensity signal-positive group (10 strokes, 5 TIAs) and in 4 (12.9%) of 31 in the intraplaque high-intensity signal-negative group (3 strokes, 1 TIA). Ischemic events occurred within the 6-month period preceding imaging in 18 (94.7%) of 19 cases. The univariate odds ratio of the association of intraplaque high-intensity signal with any prior ischemic event was 14.5 (95% CI, 3.6-57.6), and the multivariate age- and sex-adjusted odds ratio was 14.2 (95% CI, 3.3-60.5). The association remained present across 1.5 T and 3T magnet field strengths. Intraplaque high-intensity signal determined from MRA sequences already in place to measure luminal stenosis is strongly associated with prior ipsilateral ischemic events. Prospective validation of these findings to predict outcome in carotid artery stenosis could provide a valuable and widely accessible stroke risk stratification tool.

MRI Plaque Imaging Detects Carotid Plaques with a High Risk for Future Cerebrovascular Events in Asymptomatic Patients

PurposeThe aim of this study was to investigate prospectively whether MRI plaque imaging can identify patients with asymptomatic carotid artery stenosis who have an increased risk for future cerebral events. MRI plaque imaging allows categorization of carotid stenosis into different lesion types (I–VIII). Within these lesion types, lesion types IV–V and VI are regarded as rupture-prone plaques, whereas the other lesion types represent stable ones.MethodsEighty-three consecutive patients (45 male (54.2%); age 54–88 years (mean 73.2 years)) presenting with an asymptomatic carotid stenosis of 50–99% according to ECST-criteria were recruited. Patients were imaged with a 1.5-T scanner. T1-, T2-, time-of-flight-, and proton-density weighted studies were performed. The carotid plaques were classified as lesion type I–VIII. Clinical endpoints were ischemic stroke, TIA or amaurosis fugax. Survival analysis and log rank test were used to ascertain statistical significance.ResultsSix out of 83 patients (7.2%) were excluded: 4 patients had insufficient MR image quality; 1 patient was lost-to-follow-up; 1 patient died shortly after the baseline MRI plaque imaging. The following results were obtained by analyzing the remaining 77 patients. The mean time of follow-up was 41.1 months.During follow-up, n = 9 (11.7%) ipsilateral ischemic cerebrovascular events occurred. Only patients presenting with the high-risk lesion types IV–V and VI developed an ipsilateral cerebrovascular event versus none of the patients presenting with the stable lesion types III, VII, and VIII (n = 9 (11.7%) vs. n = 0 (0%) during follow-up). Event-free survival was higher among patients with the MRI-defined stable lesion types (III, VII, and VIII) than in patients with the high-risk lesion types (IV–V and VI) (log rank test P<0.0001).ConclusionsMRI plaque imaging has the potential to identify patients with asymptomatic carotid stenosis who are particularly at risk of developing future cerebral ischemia. MRI could improve selection criteria for invasive therapy in the future.