Revascularization For Asymptomatic Carotid Stenosis Research Articles

Outcomes of Carotid Revascularization versus Optimal Medical Treatment Alone for Asymptomatic Carotid Stenosis: Inverse-Probability-of-Treatment Weighting Using Propensity Scores

The benefits and necessity of revascularization for asymptomatic carotid stenosis remains under debate. This study aimed to determine the more durable and beneficial alternative between carotid revascularization and optimal medical treatment (OMT) alone for asymptomatic carotid stenosis. We performed a retrospective analysis of patients with asymptomatic severe carotid stenosis at a tertiary institution between 1994 and 2017. We compared revascularization (carotid endarterectomy [CEA] and carotid artery stenting [CAS]) with OMT alone by using inverse-probability-of-treatment weighting with propensity scores to account for selection bias. The primary end point was a composite of any stroke, myocardial infarction, and death within 30 days, plus ipsilateral stroke thereafter. A total of 1089 patients were included in the analysis (56% CEA, 25% CAS, 19% OMT alone). Patients who underwent CAS consistently showed greater risk regarding the primary composite end point compared with those who received OMT alone (hazard radio [HR] 3.32, 95% confidence interval 1.014-10.868; P= 0.047), but the CEA group showed no significant difference (HR 1.19, 95% confidence interval 0.385-4.584; P= 0.761). The CAS group had the greatest rates of any stroke within 30 days (4.0%, P= 0.0006) and ipsilateral stroke thereafter (3.68%, P= 0.0009). There was no death within 30 days. In the long-term outcomes, neither CEA nor CAS showed significant differences in HR compared with OMT alone. Our study suggests that for stroke prevention in asymptomatic severe carotid stenosis, CAS might be inferior to the other 2 options regarding early outcomes. However, further investigation is required regarding the efficacy and durability of OMT alone.

Balance and Mobility Function Improve After Revascularization for Asymptomatic Carotid Stenosis

Asymptomatic carotid stenosis (ACS) has recently been associated with cognitive impairment. We have found that approximately 50% of patients with ACS demonstrate cognitive impairment with deficits seen in working memory, attention, and learning. Based on these findings, we studied the association between carotid stenosis and mobility function. We found similar impairments in balance and mobility that worsened with increasing degrees of stenosis. Because these deficits were associated with concomitant stenosis-related impairment in cerebrovascular hemodynamics, we hypothesized that carotid revascularization in patients with high-grade (≥70% diameter-reducing) ACS would lead to improved balance and mobility function.

Normalization of reduced functional connectivity after revascularization of asymptomatic carotid stenosis

Internal carotid artery stenosis is a risk factor for ischemic stroke. Even in the absence of visible structural brain changes, patients with asymptomatic stenosis are prone to cognitive impairment. On a neuronal level, it was suggested that stenosis may lead to disturbed functional brain connectivity. If so, carotid revascularization should have an effect on hypothesized brain network disturbances. We studied functional connectivity in a motor network by resting-state electroencephalography in 12 patients with high grade asymptomatic carotid stenosis before and after interventional or surgical revascularization as compared to 23 controls. In patients with stenosis, functional connectivity of neural oscillations was significantly decreased prior and improved returning to normal connectivity after revascularization. In a subgroup of patients, also studied by contrast perfusion magnetic resonance imaging, reduced connectivity was associated with decreased regional brain perfusion reflected by increased mean transit time in the middle cerebral artery borderzone. Cognitive testing revealed only minor differences between patients and controls. In summary, we identified oscillatory connectivity changes in patients with asymptomatic carotid stenosis correlating with regional hypoperfusion, which both normalized after revascularization. Hence, electrophysiological changes might be a reversible precursor preceding macroscopic structural brain damage and behavioral impairment in patients with asymptomatic carotid stenosis.

Trials and Frontiers in Carotid Endarterectomy and Stenting.

Based on the strength of randomized trials from the 1990s, major societal guidelines recommend carotid endarterectomy (CEA) for severe (≥70%), symptomatic carotid stenosis if an operative stroke/death rate of <6% can be maintained (history and major trials in carotid revascularization are summarized in the online-only Data Supplement).1–4 Though the benefit is less evident, most guidelines also recommend consideration of CEA for 50% to 69% symptomatic stenosis.2–4 There are subtle differences in recommendations regarding carotid artery stenting (CAS) in symptomatic patients. Some guidelines stipulate that CEA should be preferred over CAS in patients with severe (≥70%) symptomatic carotid stenosis,2,5 especially if >70 years old,4 whereas others position CAS as an alternative.1,3 Though the risk of operative stroke/death is higher with CAS, major randomized clinical trials (RCTs) report event rates under the recommended 6% cutoff for both treatment modalities. Regarding asymptomatic disease, CEA is recommended for patients with stenosis ≥60% to 70% in highly selected patients as long as operative stroke/death rates <3% can be maintained.1 A predicted life expectancy of at least 3 to 5 years has also been suggested.2 The 3% threshold has been easily met by CEA cohorts in the CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial; 1.4%)6 and the ACT1 (Asymptomatic Carotid Trial; 1.7%),7 suggesting that an even lower threshold may be appropriate. Controversially, some guidelines have recommended that CAS can be considered in highly selected patients with asymptomatic carotid stenosis ≥60% to 70%,1,4,8 whereas others argue that the evidence remains insufficient.2 The lack of consensus in the management of asymptomatic carotid stenosis is reflective of an ongoing need for high-quality RCT data to guide practice. ### CEA Operative Stroke Risk and High Risk Designation Most clinical trials in carotid revascularization have focused …

Ethnicity, Race, and Postoperative Stroke Risk Among 53,593 Patients with Asymptomatic Carotid Stenosis Undergoing Revascularization.

The incidence of postoperative stroke after carotid endarterectomy is an uncommon event, and differences by racial and ethnic subgroups are not described fully in the literature. To investigate the impact of race and ethnicity on postoperative stroke risk among patients with asymptomatic carotid stenosis undergoing carotid endarterectomy. The American College of Surgeons National Surgical Quality Improvement Program database was searched for patients between the dates 2008 and 2015 to identify patients undergoing carotid endarterectomy with no history of stroke. Four racial and ethnic subgroups were included: non-Hispanic white, Hispanic white, non-Hispanic back, and non-Hispanic Asian. In addition to a descriptive statistical analysis, univariate and multivariate regression models were created to adjust for cardiovascular and perioperative risk factors and corrected for multiple comparisons. Among the 53,593 patients identified meeting the inclusion criteria, 788 (1.45%) patients experienced a stroke within 30 days. The non-Hispanic white group compared with the minority subgroups had a lower risk of postoperative stroke (1.43% vs. 1.67%, P= 0.18). The greatest difference was between the non-Hispanic white and Hispanic white groups, but this was not significant on multivariable analysis (odds ratio 1.40, 95% confidence interval 0.97-2.02, P= 0.08) after adjustment for risk stroke factors. The strongest predictors of postoperative stroke were perioperative blood transfusion, dependent functional status, and longer operative time. There was no difference between the racial and ethnic groups and the proportion of postoperative stroke among patients undergoing revascularization for asymptomatic carotid stenosis.

Stroke Caused by Extracranial Disease.

Extracranial internal carotid artery atherosclerotic occlusive disease is a common ischemic stroke mechanism. Vascular risk factor control remains the cornerstone of stroke prevention in patients with both asymptomatic and symptomatic carotid occlusive diseases. Intensive medical therapy refers to the contemporary approach of antiplatelet therapy, blood pressure control, low-density lipoprotein reduction, and lifestyle modification to reduce stroke risk. Carotid revascularization with endarterectomy or angioplasty and stenting are established treatments for patients with symptomatic carotid stenosis ≥70%. Previously accepted ischemic stroke preventative strategies, such as carotid revascularization for asymptomatic carotid stenosis, require reassessment given advances in both medical therapy and surgical techniques. The purpose of this review is to describe contemporary approaches to the management of extracranial carotid atherosclerotic occlusive disease and the basis of these recommendations. Results from recently published clinical trials will be highlighted in addition to updated information from clinical trials addressing knowledge gaps in prevention of stroke caused by extracranial disease.

Common Reasons That Asymptomatic Patients Who Are 65 Years and Older Receive Carotid Imaging.

National guidelines do not agree on the role of carotid screening in asymptomatic patients (ie, patients who have not had a stroke or transient ischemic attack). Recently, several physician organizations participating in the Choosing Wisely campaign have identified carotid imaging in selected asymptomatic populations as being of low value. However, the majority of patients who are evaluated for carotid stenosis and subsequently revascularized are asymptomatic. To better understand why asymptomatic patients who undergo revascularization receive initial carotid imaging. Retrospective cohort study of 4127 Veterans Health Administration patients 65 years and older undergoing carotid revascularization for asymptomatic carotid stenosis between 2005 and 2009. Indications for carotid ultrasounds were extracted using trained abstractors. Frequency of indications and appropriateness of initial carotid ultrasound imaging for patients within each rating category after the intervention were reported. The mean (SD) age of this cohort of 4127 patients was 73.6 (5.9) years; 4014 (98.8%) were male. Overall, there were 5226 indications for 4063 carotid ultrasounds. The most common indications listed were carotid bruit (1578 [30.2% of indications]) and follow-up for carotid disease (stenosis/history of carotid disease) in patients who had previously documented carotid stenosis (1087 [20.8% of indications]). Multiple vascular risk factors were the next most common indication listed. Rates of appropriate, uncertain, and inappropriate imaging were 5.4% (227 indications), 83.4% (3387 indications), and 11.3% (458 indications), respectively. Among the most common inappropriate indications were dizziness/vertigo and syncope. Among the 4063 patients, 3373 (83.0%) received a carotid endarterectomy. Overall, 663 procedures were performed in patients 80 years and older. Carotid bruit and follow-up for carotid disease accounted for approximately half of all indications provided by physicians for carotid testing. Strong consideration should be given to improving the evidence base around carotid testing, especially around monitoring stenosis over long periods and evaluating carotid bruits. Targeting carotid ultrasound ordering with decision support tools may also be an important step in reducing use of low-value imaging.

Carotid Stenosis in Cardiac Surgery-No Difference in Postoperative Outcomes.

Debate over revascularization of asymptomatic carotid stenosis before cardiac surgery is ongoing. In this study, we analyze cardiac surgery outcomes in patients with asymptomatic carotid stenosis at a single hospital. In this study, 1,781 patients underwent cardiac surgery from January 2012 to June 2013; 1,357 with preoperative screening carotid duplex were included. Patient demographics, comorbidities, degree of stenosis, postoperative complications, and mortality were evaluated. Chi-square test and logistic regression analysis were performed. Asymptomatic stenosis was found in 403/1,357 patients (29.7%; 355 moderate and 48 severe). Patients with stenosis, compared with those without, were older (71.7 ± 11 vs. 66.3 ± 12 years; p < 0.01). Females were more likely to have stenosis (odd ratio, = 1.7; 95% confidence interval, 1.4-2.2); however, patients were predominantly male in both groups. There were no significant differences in the rates of mortality and postoperative complications, including stroke and transient ischemic attack (TIA). Postoperative TIA occurred in 3/1,357(0.2%); only one had moderate stenosis. Inhospital stroke occurred in 21/1,357 (1.5%) patients; stroke rates were 2.3% (8/355) with moderate stenosis and 2.1% (1/48) severe stenosis. There were 59/1,357 (4.3%) deaths; patients with stenosis had a mortality rate of 4.2% (17/403); however, no postoperative stroke lead to death. Multivariable logistic regression analysis with adjustment for age, gender, race, comorbidities, and postoperative complications did not show an impact of carotid stenosis on postoperative mortality and development of stroke after cardiac surgery. This study suggests that patients with asymptomatic carotid stenosis undergoing cardiac surgery are not at increased risk of postoperative complications and mortality; thus, prophylactic carotid revascularization may not be indicated.

Abstract 17291: Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis: CREST-2 update

Purpose: The safety of revascularization for asymptomatic carotid stenosis, and the efficacy of medical therapy for stroke prevention have improved. Therefore, results of prior randomized trials may not apply to current treatment decisions. The NINDS-funded CREST-2 will compare carotid endarterectomy and intensive medical therapy (IMT) versus IMT alone (n=1240), and carotid stenting and IMT versus IMT alone (n=1240) in asymptomatic patients with≥70% stenosis. Materials &amp; Methods: CREST-2 consists of two parallel randomized clinical trials to be conducted at a target of ≈120 centers, including within NINDS StrokeNet. The composite primary outcome is stroke or death during the peri-procedural period or ipsilateral ischemic stroke thereafter up to 4 years. Blinded assessment of cognition will be done periodically. Centrally directed IMT includes tight control of blood pressure (systolic target &lt;140 mm Hg) and cholesterol (LDL target &lt;70 mg/dl) as well as lifestyle coaching. Results: As of June 12, 2015, 94 centers have been approved by the Site Selection Committee. Credentialing is ongoing, with 198 approved surgeons and 64 approved interventionists; 124 additional conditionally approved interventionists will be able to submit additional cases for review under the CREST-2 Registry. The Centers for Medicare and Medicaid will offer CAS reimbursement for Registry enrollees. As of June 12, 2015, there are 39 actively enrolling centers, and 37 patients have been randomized. Conclusion: CREST-2 is designed to identify the best approach for asymptomatic carotid stenosis. The first patient was randomized in December, 2014. An update will be provided regarding the numbers of patients randomized, centers certified, as well as surgeons and interventionists fully approved. Registration: ClinicalTrials.gov Identifier: NCT02089217

Stroke: advances in medical therapy and acute stroke intervention.

Evidence-based therapeutic options for stroke continue to emerge based on results from well-designed clinical studies. Ischemic stroke far exceeds hemorrhagic stroke in terms of prevalence and incidence, both in the USA and worldwide. The public health effect of reducing death and disability related to ischemic stroke justifies the resources that have been invested in identifying safe and effective treatments. The emergence of novel oral anticoagulants for ischemic stroke prevention in atrial fibrillation has introduced complexity to clinical decision making for patients with this common cardiac arrhythmia. Some accepted ischemic stroke preventative strategies, such as carotid revascularization for asymptomatic carotid stenosis, require reassessment, given advances in risk factor management, antithrombotic therapy, and surgical techniques. Intra-arterial therapy, particularly with stent retrievers after intravenous tissue plasminogen activator, has recently been demonstrated to improve functional outcomes and will require investment in system-based care models to ensure that effective treatments are received by patients in a timely fashion. The purpose of this review is to describe recent advances in medical and surgical approaches to ischemic stroke prevention and acute treatment. Results from recently published clinical trials will be highlighted along with ongoing clinical trials addressing key questions in ischemic stroke management and prevention where equipoise remains.

Revascularization of asymptomatic carotid stenosis is not appropriate in patients on dialysis

Outcomes of carotid endarterectomy (CEA) or carotid angioplasty and stenting (CAS) for asymptomatic disease in patients on dialysis are not well characterized, with questionable stroke prevention and survival. This study reports outcomes of carotid revascularization in asymptomatic dialysis patients in the United States. Using United States Renal Data System (USRDS) databases, we identified all dialysis patients who underwent CEA or CAS for asymptomatic disease from 2005 to 2008. CEA and CAS were identified by Current Procedural Terminology (American Medical Association, Chicago, Ill) codes, and symptom status and comorbidities by International Classification of Diseases-9th Revision, Clinical Modification codes. Primary outcomes were stroke, cardiac complications, and death at 30 days and at 1 and 3 years. Predictors of death were identified using multivariate regression models. Of 738,561 dialysis patients, 2131 asymptomatic patients underwent carotid revascularization (1805 CEA, 326 CAS). The mortality rate was 4.7% at 30 days (4.6% CEA, 4.9% CAS; P = .807). Kaplan-Meier estimates of survival were 75.1% at 1 year (75.9% CEA, 70.7% CAS) and 43.4% at 3 years (43.7% CEA, 41.6% CAS). The stroke rate was 6.5% at 30 days (6.4% CEA, 6.9% CAS; P = .774) and 13.6% at 1 year (13.3% CEA, 15.0% CAS; P = .490). Cardiac complications occurred in 22.0% of patients (3.3% myocardial infarction) at 30 days (22.2% CEA, 20.6% CAS; P = .525). The combined stroke or death rate was 10.2% at 30 days (10.1% CEA, 10.9% CAS; P = .490) and 33.5% at 1 year (32.2% CEA, 39.6% CAS; P = .025). Age >70 years at the time of surgery and increased time on dialysis were predictive of death, whereas a history of renal transplant was a protective factor. Patients on dialysis have high perioperative and long-term stroke or death rates after CEA or CAS for asymptomatic stenosis, with a median survival that is less than recommended by current guidelines. As a result, carotid intervention in these patients appears to be inappropriate.

Asymptomatic Carotid Stenosis: Immediate Revascularization or Watchful Waiting?

Based on several randomized clinical trials, carotid revascularization has been shown to reduce future stroke risk among individuals with severe asymptomatic carotid stenosis. However, a well-recognized problem with such prophylactic intervention is the risk of periprocedural stroke, death, or myocardial infarction. If actual stroke risk with asymptomatic carotid stenosis can be reduced significantly by aggressive medical management, carotid revascularization may yield marginal benefit or even cause harm especially in those with limited life expectancy. Based on recent observational data, it is becoming apparent that the stroke risk in this population has been declining with better medical management alone. This has prompted a few to avoid carotid revascularization for asymptomatic carotid stenosis altogether. Others feel such conclusions cannot be made with observational data alone. In the midst of this controversy, it is important that clinicians perform carotid revascularization on a case by case basis while ensuring optimal medical management in all patients. An algorithmic approach to decision making based on available evidence will enable clinicians to personalize patient management with efficiency.

Revascularization of Asymptomatic Carotid Stenosis Is Not Appropriate in Patients on Dialysis

Revascularization of Asymptomatic Carotid Stenosis Is Not Appropriate in Patients on Dialysis