Carotid artery stenting has increased rates of postprocedure stroke, death, and resource utilization than does carotid endarterectomy in the United States, 2005

Preoperative Risk Factors Impacting Length of Stay After Transcarotid Artery Revascularization

BACKGROUND

Transcarotid artery revascularization (TCAR), using interoperative flow reversal is a unique, hybrid operation utilized in treating critical carotid artery stenosis. Over the past decade, TCAR has been increasingly used to treat asymptomatic carotid artery disease and has a similar risk profile to traditional carotid endarterectomy. Postoperative length of stay (LOS) has a significant impact on cost-effectiveness and quality outcomes in this expanded setting. The objective of this study is to develop a multivariate regression model to identify key preoperative variables and their impact factor on LOS after TCAR for asymptomatic carotid artery stenosis. We hypothesized that high-risk preoperative patient factors historically identified in carotid endarterectomy would similarly impact LOS after TCAR.

METHODS

A multi-institution, retrospective study of all adult patients undergoing TCAR with flow-reversal for intraoperative neuroprotection was performed using the Society for Vascular Surgery Vascular Quality Initiative (VQI) from January 2016 to August 2021. Patients with prolonged preoperative hospitalization (preoperative LOS ≥1 day) were excluded to enhance the capture of carotid artery stenosis as the index admission. Univariate analysis was done on preoperative factors against LOS using nonparametric statistical tests. A multivariate model was then constructed using a negative binomial regression. The study population was split into 80% "training" data for model formulation and 20% "test" data for model validation.

RESULTS

Thirteen thousand four hundred eighty-three patients undergoing TCAR for asymptomatic carotid stenosis met the study's inclusion criteria with a median postoperative LOS of 1.82 days. Factors in VQI found to have a significant effect on LOS and retained in the multivariate model were lesion type (restenosis versus atherosclerotic), age, gender, chronic obstructive pulmonary disease, preoperative beta blocker, calcific lesion burden, hypertension status, and race (P < 0.05). The model accurately predicted LOS after TCAR within 1 day for 86.04% and within 2 days for 94.51% of patients in the test population.

CONCLUSIONS

This large-scale analysis from 2016 to 2021 spans a considerable expansion in the practice of TCAR for asymptomatic carotid disease. All preoperative variables shown to significantly increase the postoperative LOS were derived from the VQI data set. As LOS is a measure of health-care efficiency and cost-effectiveness, this model can be used to identify patients at risk for increased postoperative LOS. It has the potential to be incorporated into a patient/physician decision support tool to optimize resource planning and patient selection for elective TCAR.

Increased Regional Market Competition is Associated with a Lower Threshold for Revascularization in Asymptomatic Carotid Artery Stenosis

BACKGROUND

Revascularization practices with respect to asymptomatic carotid stenosis (ACAS) are known to vary widely among proceduralists. In addition, regional market competition has been previously shown to drive more aggressive practices in a number of surgical procedures. The aim of our study was to examine the association of regional market competition with revascularization thresholds for ACAS.

METHODS

All patients undergoing carotid revascularization in the Vascular Quality Initiative carotid endarterectomy and stenting databases (2016-2020) were included. High-grade carotid stenosis was defined as ≥80%. We calculated the Herfindahl-Hirschman Index (HHI; a measure of physician market competition) for each U.S region as defined by the U.S Department of Health and Human Services. Logistic regression was used to examine the association of degree of carotid stenosis at revascularization with HHI stratified by symptomatology, adjusting for age, sex, race, insurance, and revascularization modality.

RESULTS

Of 92,243 carotid interventions, 57,094 (61.9%) were performed for ACAS and 35,149 (38.1%) were performed for symptomatic carotid stenosis (SCAS). ACAS patients undergoing revascularization for moderate-grade stenosis were significantly less likely to be aspirin (85.6% vs. 86.3%), clopidogrel (41.3% vs. 45.1%), dual anti-platelet therapy (35.9% vs. 39.2%) and systemic anticoagulants (10.9 vs. 11.7%) compared to high-grade stenosis (all P < 0.05). Multivariable analysis demonstrated that decreased local market competition was independently associated with a lower odds of revascularization for moderate versus high-grade ACAS (odds ratio OR: 0.99 per 10 point increase in HHI, 95% confidence interval CI: 0.98-0.99). There was no association of local market competition with degree of carotid stenosis at time of revascularization among patients with SCAS (OR: 1.00 per 10 point increase in HHI, 95% CI: 0.99-1.00). Among ACAS patients, patients with moderate-grade stenosis had a higher odds ratio of in-hospital stroke or death compared to patients with high-grade stenosis (OR: 1.22, 95% CI 1.03-1.45). This association was not redemonstrated in the SCAS group (OR: 0.92, 95% CI: 0.80-1.06).

CONCLUSIONS

Increased local market competition is associated with a lower threshold for revascularization of ACAS. There is no association between regional market competition and revascularization threshold for SCAS. These findings, combined with the significantly increased risk of perioperative stroke/death among moderate-grade ACAS patients, suggest that competition among proceduralists may result in a higher tolerance for increased operative risk in patients who might otherwise be reasonable candidates for surveillance.

High resolution data modifies intensive care unit dialysis outcome predictions as compared with low resolution administrative data set

High resolution clinical databases from electronic health records are increasingly being used in the field of health data science. Compared to traditional administrative databases and disease registries, these newer highly granular clinical datasets offer several advantages, including availability of detailed clinical information for machine learning and the ability to adjust for potential confounders in statistical models. The purpose of this study is to compare the analysis of the same clinical research question using an administrative database and an electronic health record database. The Nationwide Inpatient Sample (NIS) was used for the low-resolution model, and the eICU Collaborative Research Database (eICU) was used for the high-resolution model. A parallel cohort of patients admitted to the intensive care unit (ICU) with sepsis and requiring mechanical ventilation was extracted from each database. The primary outcome was mortality and the exposure of interest was the use of dialysis. In the low resolution model, after controlling for the covariates that are available, dialysis use was associated with an increased mortality (eICU: OR 2.07, 95% CI 1.75-2.44, p<0.01; NIS: OR 1.40, 95% CI 1.36-1.45, p<0.01). In the high-resolution model, after the addition of the clinical covariates, the harmful effect of dialysis on mortality was no longer significant (OR 1.04, 95% 0.85-1.28, p = 0.64). The results of this experiment show that the addition of high resolution clinical variables to statistical models significantly improves the ability to control for important confounders that are not available in administrative datasets. This suggests that the results from prior studies using low resolution data may be inaccurate and may need to be repeated using detailed clinical data.

Asymptomatic carotid artery stenosis: a summary of current state of evidence for revascularization and emerging high-risk features

Carotid artery stenosis is a leading cause of ischemic stroke. While management of symptomatic carotid stenosis is well established, the optimal approach in asymptomatic carotid artery stenosis (aCAS) remains controversial. The rapid evolution of medical therapies within the time frame of existing landmark aCAS surgical revascularization trials has rendered their findings outdated. In this review, we sought to summarize the controversies in the management of aCAS by providing the most up-to-date medical and surgical evidence. Subsequently, we compile the evidence surrounding high-risk clinical and imaging features that might identify higher-risk lesions. With this, we aim to provide a practical framework for a precision medicine approach to the management of aCAS.

Extra-Cranial Carotid Artery Stenosis: An Objective Analysis of the Available Evidence

Background and Purpose

Carotid stenosis is arterial disease narrowing of the origin of the internal carotid artery (main brain artery). Knowing how to best manage this is imperative because it is common in older people and an important cause of stroke. Inappropriately high expectations have grown regarding the value of carotid artery procedures, such as surgery (endarterectomy) and stenting, for lowering the stroke risk associated with carotid stenosis. Meanwhile, the improving and predominant value of medical intervention (lifestyle coaching and medication) continues to be underappreciated.

Methods and Results

This article aims to be an objective presentation and discussion of the scientific literature critical for decision making when the primary goal is to optimize patient outcome. This compilation follows from many years of author scrutiny to separate fact from fiction. Common sense conclusions are drawn from factual statements backed by original citations. Detailed research methodology is given in cited papers. This article has been written in plain language given the importance of the general public understanding this topic. Issues covered include key terminology and the economic impact of carotid stenosis. There is a summary of the evidence-base regarding the efficacy and safety of procedural and medical (non-invasive) interventions for both asymptomatic and symptomatic patients. Conclusions are drawn with respect to current best management and research priorities. Several "furphies" (misconceptions) are exposed that are commonly used to make carotid stenting and endarterectomy outcomes appear similar. Ongoing randomized trials are mentioned and why they are unlikely to identify a routine practice indication for carotid artery procedures. There is a discussion of relevant worldwide guidelines regarding carotid artery procedures, including how they should be improved. There is an outline of systematic changes that are resulting in better application of the evidence-base.

Conclusion

The cornerstone of stroke prevention is medical intervention given it is non-invasive and protects against all arterial disease complications in all at risk. The "big" question is, does a carotid artery procedure add patient benefit in the modern era and, if so, for whom?

Accurate classification of carotid endarterectomy indication using physician claims and hospital discharge data

BACKGROUND AND PURPOSE

Studies of carotid endarterectomy (CEA) require stratification by symptomatic vs asymptomatic status because of marked differences in benefits and harms. In administrative datasets, this classification has been done using hospital discharge diagnosis codes of uncertain accuracy. This study aims to develop and evaluate algorithms for classifying symptomatic status using hospital discharge and physician claims data.

METHODS

A single center's administrative database was used to assemble a retrospective cohort of participants with CEA. Symptomatic status was ascertained by chart review prior to linkage with physician claims and hospital discharge data. Accuracy of rule-based classification by discharge diagnosis codes was measured by sensitivity and specificity. Elastic net logistic regression and random forest models combining physician claims and discharge data were generated from the training set and assessed in a test set of final year participants. Models were compared to rule-based classification using sensitivity at fixed specificity.

RESULTS

We identified 971 participants undergoing CEA at the Vancouver General Hospital (Vancouver, Canada) between January 1, 2008 and December 31, 2016. Of these, 729 met inclusion/exclusion criteria (n = 615 training, n = 114 test). Classification of symptomatic status using hospital discharge diagnosis codes was 32.8% (95% CI 29-37%) sensitive and 98.6% specific (96-100%). At matched 98.6% specificity, models that incorporated physician claims data were significantly more sensitive: elastic net 69.4% (59-82%) and random forest 78.8% (69-88%).

CONCLUSION

Discharge diagnoses were specific but insensitive for the classification of CEA symptomatic status. Elastic net and random forest machine learning algorithms that included physician claims data were sensitive and specific, and are likely an improvement over current state of classification by discharge diagnosis alone.

Retinal emboli after cervicopetrous junction internal carotid artery pseudoaneurysm stenting

Purpose

To describe acute and chronic retinal ischemic changes following an internal carotid artery pseudoaneurysm stenting procedure, and to review current evidence for risk factors and management of post-procedural retinal ischemic events.

Observation

A 50-year-old man presented with a 3-month history of pulsatile tinnitus, headache, and intermittent blurry vision. A CT angiogram of head and neck showed bilateral cervicopetrous internal carotid artery (ICA) pseudoaneurysms. The patient underwent successful repair with angioplasty and stenting of the flow-limiting high-grade (>95%) stenosis of his left high cervical ICA. On post-operative day 1, the patient reported monocular vision loss with a large central scotoma. He was found to have a central macular area of retinal whitening and multiple areas of perivascular retinal whitening on exam, concerning for retinal artery occlusions secondary to peri-procedural emboli. Dual antiplatelet therapy was started and a stroke evaluation was performed. Two months later, his visual acuity in the affected eye was counting fingers and his left eye fundus examination was notable for multiple areas of scattered hemorrhages, microaneurysms, and retinal exudates in the distribution of prior retinal ischemia. OCT imaging revealed atrophic changes in the left macula. Subsequently, the patient completed stage-2 repair of the left ICA pseudoaneurysm followed by uncomplicated repair of the right ICA. Four months later, his left eye visual acuity and retinal findings remained stable.

Conclusions and Importance

Post-procedure retinal emboli and ischemia are important, vision threatening possible ocular complications for patients undergoing carotid vascular and endovascular procedures.

The conundrum of asymptomatic carotid stenosis-determinants of decision and evidence

Management of asymptomatic carotid disease continues to challenge medical practice and present evidence is often conflicting. Stroke is a significant burden in Public Health and 11% to 15% appear as first neurologic event associated with asymptomatic carotid stenosis. Randomized trials provided support for Guidelines and Recommendations to intervene on asymptomatic stenosis, but at a known cost of a high number of unnecessary operations. Conflicting evidence from natural history studies and the widespread use of proper medical management including risk factors control, lowering-lipid drugs and strict control of arterial hypertension have reduced the incidence of strokes associated to asymptomatic carotid disease challenging established practice. Need to identify vulnerable lesions prone to develop thromboembolic brain events and also vulnerable patients at a higher risk of stroke is necessary and essential to further improve effectiveness of our interventions. After review of published literature on natural history of asymptomatic carotid stenosis, diagnostic methods to identify plaque vulnerability and present-day results of both endarterectomy and stenting, a strategy for management of asymptomatic carotid stenosis is suggested aiming to reduce unnecessary interventions and effectively contribute to stroke prevention.

Contemporary Trends in Physician Utilization Rates of CEA and CAS for Asymptomatic Carotid Stenosis among Medicare Beneficiaries

BACKGROUND

Carotid revascularization for asymptomatic carotid artery stenosis (ACAS) has become increasingly controversial in the past few decades as the best medical therapy has improved. The aim of this study was to assess and define contemporary trends in the rate of carotid revascularization procedures for ACAS in the United States and to characterize outlier physicians performing a higher rate of asymptomatic revascularization compared to their peers.

METHODS

We used 100% Medicare fee-for-service claims to identify all patients who were newly diagnosed with ACAS between 01/2011-06/2018. Patients with symptomatic carotid artery stenosis, those with prior carotid revascularization, and surgeons who performed ≤10 CEAs during the study period were excluded. We used a hierarchical multivariable logistic regression model to evaluate patient and physician characteristics associated with undergoing a carotid endarterectomy or carotid artery stent procedure within 3 months after the initial diagnosis of ACAS. We also assessed temporal trends in carotid revascularization rates over time using the Cochran-Armitage Trend Test.

RESULTS

Overall, 795,512 patients (median age 73.9 years, 50.9% male, 87.6% white) had a first-time diagnosis of ACAS during the study period, of which 23,481 (3.0%) underwent carotid revascularization within 3 months. There was a significant decline in overall carotid artery revascularization rates over time (2011: 3.2% vs. 2018: 2.1%; P < 0.001). The median and mean physician-specific carotid revascularization rates were 2.0% (IQR 0.0%-6.3%) and 4.7% ± 7.1%, respectively. Three-hundred and fifty physicians (5.2%) had carotid revascularization rates ≥19%, which was more than 2 standard deviations above the mean. After adjusting for patient-level characteristics, physician-level variables associated with carotid revascularization for newly diagnosed ACAS included male sex (adjusted OR 1.59, 95% CI 1.35-1.89), more years in practice (≥31 vs. <10 years, aOR 1.64, 95% CI 1.32-2.04), rural practice location (aOR 1.34, 95% CI 1.18-1.52), Southern region practice location (versus Northeast, aOR 1.54, 95% CI 1.39-1.69), and lower volume of ACAS patients (lower versus upper tertile, aOR 2.62, 95% CI 2.39-2.89). Cardiothoracic surgeons had a 1.52-fold higher odds of carotid revascularization compared to vascular surgeons (95% CI 1.36-1.68), whereas cardiologists and radiologists had lower intervention rates (both, P < 0.05).

CONCLUSIONS

The current early revascularization rate for newly diagnosed ACAS is <5% among proceduralists in the United States, and has been decreasing steadily since 2014. There are particular physician-level characteristics that are associated with higher rates of carotid revascularization that cannot be fully contextualized without high-level contemporary outcomes data to guide decision making in ACAS.

Mechanical Thrombectomy in Acute Ischemic Stroke Patients Performed Within and Outside Clinical Trials in the United States

BACKGROUND

A better understanding of differences in outcomes of mechanical thrombectomy performed within and outside clinical trials will assist in optimal implementation of the procedure for acute ischemic stroke patients in general practice.

OBJECTIVE

To identify differences in demographic and clinical characteristics and outcomes related to mechanical thrombectomy in patients treated within clinical trials and those treated outside clinical trials in a large national cohort.

METHODS

We compared the patient characteristics and associated in-hospital outcomes of mechanical thrombectomy in acute ischemic stroke patients performed within and outside clinical trials using the Nationwide Inpatient Sample from 2013 to 2015. We analyzed in-hospital mortality (primary outcome) and moderate to severe disability (secondary outcome) based on discharge disposition after adjusting for potential confounders.

RESULTS

Of 23 375 patients who underwent mechanical thrombectomy, 430 (1.8%) underwent the procedure as part of a clinical trial. After adjusting for age, gender, and the teaching status of the hospital, patients treated within a clinical trial had lower rates of in-hospital mortality (odds ratio [OR] 0.14; 95% CI .03 to .71; P < .001). Among patients discharged alive, the rate of moderate to severe disability (OR .43; 95% CI .26 to .71; P < .001) was lower among those patients treated within a clinical trial. There was no difference in odds of post-thrombectomy intracerebral or subarachnoid hemorrhage between the two groups.

CONCLUSION

Mechanical thrombectomy performed as part of clinical trials was associated with lower rates of in-hospital mortality and lower rates of moderate to severe disability compared with those performed outside clinical trials.

Long-term stroke risk with carotid endarterectomy in patients with severe carotid stenosis

OBJECTIVE

Informed debate regarding the optimal use of carotid endarterectomy (CEA) for stroke risk reduction requires contemporary assessment of both long-term risk and periprocedural risk. In this study, we report long-term stroke and death risk after CEA in a large integrated health care system.

METHODS

All patients with documented severe (70%-99%) stenosis from 2008 to 2012 who underwent CEA were identified and stratified by asymptomatic or symptomatic indication. Those with prior ipsilateral interventions were excluded. Patients were followed up through 2017 for the primary outcomes of any stroke/death within 30 days of intervention and long-term ipsilateral ischemic stroke; secondary outcomes were any stroke and overall survival.

RESULTS

Overall, 1949 patients (63.2% male; mean age, 71.3 ± 8.9 years) underwent 2078 primary CEAs, 1196 (58%) for asymptomatic stenosis and 882 (42%) for symptomatic stenosis. Mean follow-up was 5.5 ± 2.7 years. Median time to surgery was 72.0 (interquartile range, 38.5-198.0) days for asymptomatic patients and 21.0 (interquartile range, 5.0-55.0) days for symptomatic patients (P < .001). Most of the patients' demographics and characteristics were similar in both groups. Controlled blood pressure rates were similar at the time of CEA. Baseline statin use was seen in 60.5% of the asymptomatic group compared with 39.9% in the symptomatic group (P < .001), and statin adherence by 80% medication possession ratio was 19.3% asymptomatic vs 12.4% symptomatic (P < .001). The crude overall 30-day any stroke/death rates were 0.9% and 1.5% for the asymptomatic group and the symptomatic group, respectively. The 5-year risk of ipsilateral stroke and a combined end point of any stroke/death by Kaplan-Meier survival analysis were 2.5% and 28.7% for the asymptomatic group and 4.0% and 31.4% for the symptomatic group, respectively. Unadjusted cumulative all-cause survival was 74.2% for the asymptomatic group and 71.8% for the symptomatic group at 5 years.

CONCLUSIONS

In a contemporary review of CEA, outcomes for either operative indication show low adverse events perioperatively and low long-term stroke risk up to 5 years. These results are well within consensus guidelines and published trial outcomes and should help inform the discussion around optimal CEA use for severe carotid stenosis.

Procedural Risks of Carotid Intervention in 19,000 Patients

BACKGROUND

Randomized controlled trials (RCTs) show that carotid endarterectomy (CEA) and carotid stenting (CAS) reduce long-term stroke risk in symptomatic and asymptomatic patients with carotid artery stenosis. Historical RCTs may not represent contemporary practice and administrative datasets may estimate procedural risks more reliably. We studied procedural risks after carotid intervention in a novel, international administrative data set of 18,997 patients admitted to 28 hospitals across 7 countries.

METHODS

Symptomatic and asymptomatic patients undergoing CEA (n = 16,220) and CAS (n = 2,777) between 2011 and 2015 were studied retrospectively. The primary outcome was in-hospital death within seven days. The secondary outcome was the proportion of patients whose length of hospital stay (LOS) exceeded 2 days. We also describe the rate of computerized tomography brain imaging within 2 days of CEA and CAS (proxy for stroke) as procedural strokes were not reliably recorded.

RESULTS

In symptomatic patients after CEA, mortality was 0.2% [5/2,118] (95% confidence interval: 0.1-0.5), and 57.0% [628/1,101] (54.1-60.0) had prolonged LOS. In asymptomatic patients after CEA, mortality was 0.1% [21/14,102] (0.1-0.2), and 28.5% [2,864/10,039] (27.7-29.4) had prolonged LOS. In symptomatic patients after CAS, mortality was 3.3% [10/307] (1.3-5.2), and 64.3% [144/224] (58.0-70.5) had prolonged LOS. In asymptomatic patients after CAS, mortality was 0.7% [18/2,470] (0.4-1.1), and 27.5% [601/2,187] (25.6-29.4) had prolonged LOS. After CEA, 8.1% [89/1,101] (6.5-9.7) symptomatic patients and 2.1% [207/10,039] (1.8-2.3) asymptomatic patients underwent brain imaging. After CAS, 7.1% [16/224] (4.0-10.7) symptomatic patients and 3.2% [71/2,187] (2.5-4.0) asymptomatic patients underwent brain imaging.

CONCLUSIONS

Death and LOS after CEA and CAS were higher in symptomatic than asymptomatic patients. Symptomatic patients undergoing CAS had particularly increased risk of death. This may be partly explained by case selection, with more comorbid patients preferentially undergoing CAS. While RCTs effectively compare long-term efficacy of CEA versus CAS, administrative datasets can provide reliable estimates of contemporary procedural risks.

Carotid Revascularization: Current Practice and Future Directions

Carotid stenosis is responsible for approximately 15% of ischemic strokes. Carotid revascularization significantly decreases patients' stroke risk. Carotid endarterectomy has first-line therapy for moderate-to-severe carotid stenosis after a series of pivotal randomized controlled trials were published almost 30 years ago. Revascularization with carotid stenting has become a popular and effective alternative in a select subpopulation of patients. We review the current state of the literature regarding revascularization indications, patient selection, advantages of each revascularization approach, timing of intervention, and emerging interventional techniques, such as transcarotid artery revascularization.

Hidden Readmissions after Carotid Endarterectomy and Stenting

BACKGROUND

Historically, carotid procedures incur a readmission rate of approximately 6%; however, these studies are not nationally representative and are limited to tracking only the index hospitals. We sought to evaluate a nationally representative database for readmission rates (including different hospitals) after both carotid endarterectomy (CEA) and carotid artery stenting (CAS) and determine risk factors for poor outcomes including postoperative mortality and myocardial infarction.

METHODS

This study was a retrospective analysis utilizing the 2010-2014 Nationwide Readmissions Database to query patients aged >18 years undergoing CEA or CAS. Outcomes included initial admission mortality, and 30-day readmission, including mortality and myocardial infarction (MI). Univariable analysis of 39 demographic, clinical, and hospital variables was conducted with significance set at P < 0.05. Significant variables were included in a multivariable logistic regression to identify independent risk factors for readmission. Results were weighted for national estimates.

RESULTS

There were 527,622 patients undergoing carotid procedures and 13% (n = 69,187) underwent CAS. The 30-day readmission rate was 7% (n = 35,782), and of those, 25% (n = 8,862) were readmitted to a different hospital. When controlling for other factors, CAS was a risk factor for mortality at both index admission (odds ratio [OR] 2.29 [2.11-2.49]) and 30-day readmission (OR 1.48 [1.3-1.69]) and 30-day readmissions at both index hospital (OR 1.11 [1.07-1.14]) and different hospital (OR 1.38 [1.29-1.48]). Readmission to a different hospital increased mortality risk (OR 1.45 [1.29-1.63]) but did not have an effect on MI. Postoperative infections comprised 15% of readmissions while 6% of all readmissions were for stroke.

CONCLUSIONS

Previously unreported, one in 4 readmissions after carotid procedures occur at a different hospital and this fragmentation of care could increase mortality risk after carotid procedures particularly for CAS which was also an independent risk factor for postoperative mortality and readmissions. Further validation is required to decrease unnecessary hospital after carotid procedures.

In-hospital outcomes alone underestimate rates of 30-day major adverse events after carotid artery stenting

OBJECTIVE

Outcome studies using databases collecting only hospital discharge data underestimate morbidity and mortality because of failure to capture postdischarge events. The proportion of postdischarge major adverse events is well characterized in patients undergoing carotid endarterectomy (CEA) but has yet to be characterized after carotid artery stenting (CAS).

METHODS

We retrospectively reviewed all patients undergoing CAS from 2011 to 2017 using the American College of Surgeons National Surgical Quality Improvement Program procedure targeted database to evaluate rates of 30-day major adverse events, stratified by in-hospital and postdischarge occurrences. The primary outcome was 30-day stroke/death. Multivariable analysis using purposeful selection was used to identify independent factors associated with in-hospital, postdischarge, and 30-day stroke/death events.

RESULTS

Of the 899 patients undergoing CAS, reporting of in-hospital outcomes alone would yield a stroke/death rate of 2.7%, substantially underestimating the 30-day stroke/death rate of 4.0%. In fact, 35% of stroke/deaths, 27% of strokes, 73% of deaths, 35% of cardiac events, and 35% of stroke/death/cardiac events occurred after discharge. More postdischarge stroke/death events occurred after treatment of symptomatic compared with asymptomatic patients (47% vs 27%; P < .001). During this same study period, the 30-day stroke/death rate after CEA was 2.6%, with similar proportions of postdischarge strokes (28% vs 27%; P = .51) compared with CAS but lower proportions of postdischarge deaths (55% vs 73%; P < .001). After CAS, patients experiencing postdischarge stroke/death events had a shorter postoperative length of stay compared with patients with in-hospital stroke/death (1 [1-2] vs 5 [3-10] days; P < .001). Chronic obstructive pulmonary disease was independently associated with postdischarge stroke/death (odds ratio [OR], 4.4; 95% confidence interval [CI], 1.2-16; P = .02) after CAS. Nonwhite ethnicity was independently associated with overall 30-day stroke/death (OR, 3.4; 95% CI, 1.4-7.9; P < .01), whereas statin use was associated with not having stroke/death within 30 days (OR, 0.5; 95% CI, 0.2-1.0; P = .049).

CONCLUSIONS

More than one-quarter of perioperative strokes occur following discharge after both CAS and CEA. A higher proportion of postdischarge deaths occur after CAS in symptomatic patients, which may reflect treatment of a population of higher risk patients. Further investigation is needed to elucidate the cause of postdischarge stroke to develop methods to reduce these complications.

Misconceptions regarding the adequacy of best medical intervention alone for asymptomatic carotid stenosis

BACKGROUND

Medical intervention (risk factor identification, lifestyle coaching, and medication) for stroke prevention has improved significantly. It is likely that no more than 5.5% of persons with advanced asymptomatic carotid stenosis (ACS) will now benefit from a carotid procedure during their lifetime. However, some question the adequacy of medical intervention alone for such persons and propose using markers of high stroke risk to intervene with carotid endarterectomy (CEA) and/or carotid angioplasty/stenting (CAS). Our aim was to examine the scientific validity and implications of this proposal.

METHODS

We reviewed the evidence for using medical intervention alone or with additional CEA or CAS in persons with ACS. We also reviewed the evidence regarding the validity of using commonly cited makers of high stroke risk to select such persons for CEA or CAS, including markers proposed by the European Society for Vascular Surgery in 2017.

RESULTS

Randomized trials of medical intervention alone versus additional CEA showed a definite statistically significant CEA stroke prevention benefit for ACS only for selected average surgical risk men aged less than 75 to 80 years with 60% or greater stenosis using the North American Symptomatic Carotid Endarterectomy Trial criteria. However, the most recent measurements of stroke rate with ACS using medical intervention alone are overall lower than for those who had CEA or CAS in randomized trials. Randomized trials of CEA versus CAS in persons with ACS were underpowered. However, the trend was for higher stroke and death rates with CAS. There are no randomized trial results related to comparing current optimal medical intervention with CEA or CAS. Commonly cited markers of high stroke risk in relation to ACS lack specificity, have not been assessed in conjunction with current optimal medical intervention, and have not been shown in randomized trials to identify those who benefit from a carotid procedure in addition to current optimal medical intervention.

CONCLUSIONS

Medical intervention has an established role in the current routine management of persons with ACS. Stroke risk stratification studies using current optimal medical intervention alone are the highest research priority for identifying persons likely to benefit from adding a carotid procedure.

External validation of the Vascular Study Group of New England carotid endarterectomy risk predictive model using an independent U.S. national surgical database

OBJECTIVE

Previously, we described a Vascular Study Group of New England (VSGNE) risk predictive model to predict composite adverse outcomes (postoperative death, stroke, myocardial infarction, or discharge to extended care facilities) after carotid endarterectomy (CEA). The goal of this study was to externally validate this model using an independent database.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) CEA-targeted database (2010-2014) was used to externally validate the risk predictor model of adverse outcomes after CEA previously created using the VSGNE carotid database. Emergent cases and those in which CEA was combined with another operation were excluded. Cases in which a discharge destination cannot be determined were also excluded. To assess the predictive power of our VSGNE prediction score within this sample, a receiver operating characteristic curve was constructed. Risk scores for each NSQIP patient were also computed using beta weights from the VSGNE CEA model. To further assess the construct validity of our VSGNE prediction score, the observed proportion of adverse outcomes was examined at each level of our prediction scale and within five roughly equally sized risk groups formed on the basis of our VSGNE prediction scores.

RESULTS

In this database, 10,889 cases met our inclusion criteria and were used in this analysis. The overall rate of adverse outcomes in this cohort was 8.5%. External validation of the VSGNE model on this sample showed moderately good predictive ability (area under the curve = 0.745). Patients in progressively higher risk groups, based on their VSGNE model scores, exhibited progressively higher rates of observed adverse outcomes, as predicted.

CONCLUSIONS

The VSGNE CEA risk predictive model was externally validated on an NSQIP CEA-targeted sample and showed a fairly accurate global predictive ability for adverse outcomes after CEA. Although this model has a good population concordance, the lack of cut point indicates that individual risk prediction requires more evaluation. Further studies should be geared toward identification of variables that make this risk predictive model more robust.

Comparing Long-term Mortality After Carotid Endarterectomy vs Carotid Stenting Using a Novel Instrumental Variable Method for Risk Adjustment in Observational Time-to-Event Data

IMPORTANCE

Choosing between competing treatment options is difficult for patients and clinicians when results from randomized and observational studies are discordant. Observational real-world studies yield more generalizable evidence for decision making than randomized clinical trials, but unmeasured confounding, especially in time-to-event analyses, can limit validity.

OBJECTIVES

To compare long-term survival after carotid endarterectomy (CEA) and carotid artery stenting (CAS) in real-world practice using a novel instrumental variable method designed for time-to-event outcomes, and to compare the results with traditional risk-adjustment models used in observational research for survival analyses.

DESIGN, SETTING, AND PARTICIPANTS

A multicenter cohort study was performed. The Vascular Quality Initiative, an observational quality improvement registry, was used to compare long-term mortality after CEA vs CAS. The study included 86 017 patients who underwent CEA (n = 73 312) or CAS (n = 12 705) between January 1, 2003, and December 31, 2016. Patients were followed up for long-term mortality assessment by linking the registry data to Medicare claims. Medicare claims data were available through September 31, 2015.

EXPOSURE

Procedure type (CEA vs CAS).

MAIN OUTCOMES AND MEASURES

The hazard ratios (HRs) of all-cause mortality using unadjusted, adjusted, propensity-matched, and instrumental variable methods were examined. The instrumental variable was the proportion of CEA among the total carotid procedures (endarterectomy and stenting) performed at each hospital in the 12 months before each patient's index operation and therefore varies over the study period.

RESULTS

Participants who underwent CEA had a mean (SD) age of 70.3 (9.4) years compared with 69.1 (10.4) years for CAS, and most were men (44 191 [60.4%] for CEA and 8117 [63.9%] for CAS). The observed 5-year mortality was 12.8% (95% CI, 12.5%-13.2%) for CEA and 17.0% (95% CI, 16.0%-18.1%) for CAS. The unadjusted HR of mortality for CEA vs CAS was 0.67 (95% CI, 0.64-0.71), and Cox-adjusted and propensity-matched HRs were similar (0.69; 95% CI, 0.65-0.74 and 0.71; 95% CI, 0.65-0.77, respectively). These findings are comparable with published observational studies of CEA vs CAS. However, the association between CEA and mortality was more modest when estimated by instrumental variable analysis (HR, 0.83; 95% CI, 0.70-0.98), a finding similar to data reported in randomized clinical trials.

CONCLUSIONS AND RELEVANCE

The study found a survival advantage associated with CEA over CAS in unadjusted and Cox-adjusted analyses. However, this finding was more modest when using an instrumental variable method designed for time-to-event outcomes for risk adjustment. The instrumental variable-based results were more similar to findings from randomized clinical trials, suggesting this method may provide less biased estimates of time-dependent outcomes in observational analyses.

A comparative analysis of long-term mortality after carotid endarterectomy and carotid stenting

BACKGROUND

The value of carotid intervention is predicated on long-term survival for patients to derive a stroke prevention benefit. Randomized trials report no significant difference in survival after carotid endarterectomy (CEA) vs carotid artery stenting (CAS), whereas observational studies of "real-world" outcomes note that CEA is associated with a survival advantage. Our objective was to examine long-term mortality after CEA vs CAS using a propensity-matched cohort.

METHODS

We studied all patients who underwent CEA or CAS within the Vascular Quality Initiative from 2003 to 2013 (CEA, n = 29,235; CAS, n = 4415). Long-term mortality information was obtained by linking patients in the registry to their respective Medicare claims file. We assessed the long-term rate of mortality for CEA and CAS using Kaplan-Meier estimation. We assessed the crude, adjusted, and propensity-matched (total matched pairs, n = 4261) hazard ratio (HR) of mortality for CEA vs CAS using Cox regression.

RESULTS

The unadjusted Kaplan-Meier estimated 5-year mortality was 14.0% for CEA and 18.3% for CAS. The crude HR of all-cause mortality for CEA vs CAS was 0.75 (95% confidence interval [CI], 0.70-0.81), indicating that patients who underwent CEA were 25% less likely to die before those who underwent CAS. This survival advantage persisted after adjustment for age, sex, and comorbidities (adjusted HR, 0.75; 95% CI, 0.69-0.82). This effect was confirmed on a propensity-matched analysis, with an HR of 0.76 (95% CI, 0.69-0.85). Finally, these findings were robust to subanalyses that stratified patients by presenting symptoms and were more pronounced in symptomatic patients (adjusted HR, 0.69; 95% CI, 0.61-0.79) than in asymptomatic patients (adjusted HR, 0.80; 95% CI, 0.71-0.90).

CONCLUSIONS

During the last 15 years, patients who underwent CEA in the Vascular Quality Initiative have a long-term survival advantage over those who underwent CAS in real-world practice. Despite no difference in long-term survival in randomized trials, our observational study demonstrated a survival benefit for CEA that did not diminish with risk adjustment.

Recent Advances in Primary and Secondary Prevention of Atherosclerotic Stroke

Atherosclerosis is a major cause of ischemic stroke that can be effectively prevented with appropriate lifestyle modifications and control of cardiovascular risk factors. Medical advances in recent years along with aggressive cardiovascular risk factor modifications have resulted in decreased recurrence rates of atherosclerotic stroke. Non-statin lipid-lowering molecules have recently shown clinical benefit and are recommended for very high-risk patients to reduce their risk of stroke. Aggressive hypertension treatment is crucial to reduce atherosclerotic stroke risk. Advances in antithrombotic treatments include combinations of antiplatelets and new antiplatelet agents in the acute phase post-stroke, which carries a high risk of recurrence. Intensive medical treatment has also limited the indications for carotid interventions, especially for asymptomatic disease. Intracranial atherosclerotic disease may provoke stroke through various mechanisms; it is increasingly recognized as a cause of ischemic stroke with advanced imaging and is best managed with lifestyle modifications and medical therapy. The diagnostic search for the vulnerable culprit atherosclerotic plaque is an area of intense research, from the level of the intracranial arteries to that of the aortic arch. Ultrasonography and novel magnetic resonance imaging techniques (high-resolution vessel-wall imaging) may assist in the identification of vulnerable atherosclerotic plaques as the underlying cause in cryptogenic or misdiagnosed non-atherosclerotic ischemic stroke. Vertebrobasilar atherosclerotic disease is less common than carotid artery disease; thus, high-quality data on effective prevention strategies are scarcer. However, aggressive medical treatment is also the gold standard to reduce cerebrovascular disease located in posterior circulation.

Which patients with asymptomatic carotid stenosis benefit from revascularization?

PURPOSE OF REVIEW

To summarize why there are polarized opinions regarding the management of patients with asymptomatic carotid disease and whether it is possible to identify patients who might benefit from carotid interventions.

RECENT FINDINGS

Carotid Revascularization Endarterectomy Versus Stenting Trial and Asymptomatic Carotid Trial 1 (ACT-1) recently concluded that outcomes after carotid endarterectomy and carotid stenting were not significantly different in asymptomatic patients and that procedural risks were below the accepted 3% threshold. However, systematic reviews suggest that Carotid Revascularization Endarterectomy Versus Stenting Trial/ACT-1 results may not be generalizable into routine practice. In parallel, meta-analyses suggest that stroke rates on medical therapy may be declining, suggesting that Asymptomatic Carotid Atherosclerosis Study/Asymptomatic Carotid Surgery Trial data, which have underpinned every practice guideline since 1995, are too historical for use in 2017. A recent review has, however, identified a number of clinical/imaging features that may be associated with higher rates of stroke on medical therapy.

SUMMARY

The majority of surgeons/interventionists are unlikely to accept radical changes in practice until new randomized trials confirm that the risk of stroke on modern medical therapy is significantly lower than that previously accepted. In the interim, it would be preferable to target interventions into a smaller cohort who present with clinical/imaging features that might render them 'higher risk for stroke' on medical therapy.

Provider-Induced Demand in the Treatment of Carotid Artery Stenosis: Variation in Treatment Decisions Between Private Sector Fee-for-Service vs Salary-Based Military Physicians

Importance

Although many factors influence the management of carotid artery stenosis, it is not well understood whether a preference toward procedural management exists when procedural volume and physician compensation are linked in the fee-for-service environment.

Objective

To explore evidence for provider-induced demand in the management of carotid artery stenosis.

Design, Setting, and Participants

The Department of Defense Military Health System Data Repository was queried for individuals diagnosed with carotid artery stenosis between October 1, 2006, and September 30, 2010. A hierarchical multivariable model evaluated the association of the treatment system (fee-for-service physicians in the private sector vs salary-based military physicians) with the odds of procedural intervention (carotid endarterectomy or carotid artery stenting) compared with medical management. Subanalysis was performed by symptom status at the time of presentation. The association of treatment system and of management strategy with clinical outcomes, including stroke and death, was also evaluated. Data analysis was conducted from August 15, 2015, to August 2, 2016.

Main Outcomes and Measures

The odds of procedural intervention based on treatment system was the primary outcome used to indicate the presence and effect of provider-induced demand.

Results

Of 10 579 individuals with a diagnosis of carotid artery stenosis (4615 women and 5964 men; mean [SD] age, 65.6 [11.4] years), 1307 (12.4%) underwent at least 1 procedure. After adjusting for demographic and clinical factors, the odds of undergoing procedural management were significantly higher for patients in the fee-for-service system compared with those in the salary-based setting (odds ratio, 1.629; 95% CI, 1.285-2.063; P < .001). This finding remained true when patients were stratified by symptom status at presentation (symptomatic: odds ratio, 2.074; 95% CI, 1.302-3.303; P = .002; and asymptomatic: odds ratio, 1.534; 95% CI, 1.186-1.984; P = .001).

Conclusions and Relevance

Individuals treated in a fee-for-service system were significantly more likely to undergo procedural management for carotid stenosis compared with those in the salary-based setting. These findings remained consistent for individuals with and without symptomatic disease.

Extracranial carotid stenosis: evidence based review

Extracranial cerebrovascular disease is one of the most important causes of death and disability worldwide and its treatment is based on clinical and surgical strategies, the latter being performed by conventional or endovascular techniques. The management of stenosis of the carotid bifurcation is mainly aimed at preventing stroke and has been the subject of extensive investigation. The role of clinical treatment has been re-emphasized, but carotid endarterectomy remains the first-line treatment for symptomatic patients with 50% to 99% stenosis and for asymptomatic patients with 60% to 99% stenosis. Stent angioplasty is reserved for symptomatic patients with stenosis of 50% to 99% and at high risk for open surgery due to anatomical or clinical reasons. Currently, the endovascular procedure is not recommended for asymptomatic patients who are able to undergo conventional surgical treatment. Brazil presents a trend similar to that of other countries in North America and Europe, keeping endarterectomy as the main indication for the treatment of carotid stenosis and reserving the endovascular procedure for cases in which there are contraindications for the first intervention. However, we must improve our results by reducing complications, notably the overall mortality rate.

Optimal Medical Management Reduces Risk of Disease Progression and Ischemic Events in Asymptomatic Carotid Stenosis Patients: A Long-Term Follow-Up Study

Background and Purpose: To assess the effect of optimal medical management including atherosclerotic risk factor control on ischemic stroke (IS), transient ischemic attack (TIA), carotid revascularization (CRV), and progression of severity of carotid stenosis (PSCS) in patients with asymptomatic carotid artery stenosis (ACAS). Methods: We conducted a retrospective analysis of patients with ACAS (who had at least 3 serial carotid duplex ultrasounds) for incidence of IS, TIA, and PSCS. Results: Eight hundred sixty-four patients with a mean follow-up duration of 79 ± 36 months were included. IS/TIA and CRV occurred in 12.2% of the patients and PCSS was observed in 21.5% vessels. On univariate analysis it was found that low-density lipoprotein (LDL) levels >100 mg/dL, no statin or low-potency statins, average systolic blood pressure (SBP) ≥140 mm Hg and/or diastolic blood pressure (DBP) ≥90 mm Hg and history of smoking were predictors of the combined endpoint of IS/TIA/CRV and PSCS. On multivariate analysis, it was found that LDL >100 mg/dL, no statin or low-potency statin, SBP ≥140 mm Hg and/or DBP ≥90 mm Hg, and Hx of smoking were independent predictors of PSCS. Similarly no statin or low-potency statin, SBP ≥140 mm Hg and/or DBP ≥90 mm Hg, Hx of atrial fibrillation/flutter, Hx of chronic kidney disease, and PSCS were independent predictors of IS/TIA. No statin or low-potency statin, SBP ≥140 mm Hg and/or DBP ≥90 mm Hg, diabetes mellitus, baseline carotid artery stenosis ≥70%, and PSCS were found to be independent predictors of combined endpoint IS/TIA and CRV. Conclusion: Intensive medical therapy in the patients with ACAS results in lower incidence of IS/TIA, CRV, and PSCS with a significant incremental beneficial effect.

Factors Influencing Decision Making for Carotid Endarterectomy versus Stenting in the Very Elderly

As the population ages worldwide, the number of elderly patients with carotid stenosis is also increasing. There have been many large clinical trials comparing carotid endarterectomy (CAE) versus stenting, but the inclusion criteria (i.e., symptomatic or asymptomatic), stenting methods (i.e., protection device), and primary end point (i.e., the definition of myocardial infarction and follow-up period) were different between trials. Therefore, the interpretation of those results is difficult and requires attention. When it comes to age, the patients older than 80 years were excluded or stratified to a high risk group in previous landmark trials. However, a recent guideline recommended that endarterectomy may be associated with lower stroke risk compared with carotid artery stenting in patients older than 70 years with symptomatic carotid disease. The annual risk of stroke in individuals with asymptomatic carotid stenosis is about 1-3% but the risk is about 4-12% with symptomatic stenosis without carotid intervention. Although the outcome of CAE is better than that of carotid stenting in patients older than 70 years, the perioperative risk is higher in older patients. Therefore, it is important to classify high risk patients and consider underlying disability and life expectancy of very elderly patients before deciding whether to undergo a carotid intervention. In addition, we should also consider that the stroke rate with intensive medical treatment is unknown and is currently being investigated in randomized controlled trials. Intensive medical treatment includes high intensity statins, diabetes and blood pressure control, and aggressive antiplatelet treatment. The aim of this review is to report the factors that may be responsible for the variability in the treatment of carotid stenosis, particularly in the elderly population. This will allow the readers to integrate the current available evidence to individualize the treatment of carotid stenosis in this challenging population.

The association of Carotid Revascularization Endarterectomy versus Stent Trial (CREST) and Centers for Medicare and Medicaid Services Carotid Guideline Publication on utilization and outcomes of carotid stenting among "high-risk" patients

OBJECTIVE

Since the 2004 approval by the United States Food and Drug Administration of carotid artery stenting (CAS), there have been two seminal publications about CAS reimbursement (Centers for Medicare and Medicaid Services guidelines; 2008) and clinical outcomes (Carotid Revascularization Endarterectomy versus Stent Trial [CREST]; 2010). We explored the association between these publications and national trends in CAS use among high-risk symptomatic patients.

METHODS

The most recent congruent data sets of the Nationwide Inpatient Sample (NIS) were queried for patients undergoing carotid revascularization. The sample was limited to include only patients who were defined as "high-risk" if they had a Charlson Comorbidity Score of ≥3.0. Subgroup analyses were performed of high-risk patients with symptomatic carotid stenosis. Utilization proportions of CAS were calculated quarterly from 2005 to 2011 for NIS. Three time intervals related to Centers for Medicare and Medicaid Services guidelines and CREST publication were selected: 2005 to 2008, 2008 to 2010, and after 2010. Logistic regression with piecewise linear trend for time was used to estimate different trends in CAS use for the overall high-risk sample and for neurologically asymptomatic and symptomatic cases. Multivariate logistic regression was used to compare odds of postoperative mortality and stroke between these two procedures at different time intervals independent of confounding variables.

RESULTS

During the study period, 20,079 carotid endarterectomies (CEAs) and 3447 CAS procedures were performed in high-risk patients in the NIS database. CAS utilization constituted 20.5% of carotid revascularization procedures among high-risk symptomatic patients, with a significant increase from 18.6% to 24.4% during the study period (P < .001). There was an initial increase during 2005 to 2008 in the rate of CAS compared with CEA, CAS utilization significantly decreased during 2008 to 2010 by a 3.3% decline in the odds ratio (OR) of CAS per quarter (OR, 0.967; 95% confidence interval [CI], 0.943-0.993; P = .002), and after CREST (after 2010), CAS utilization continued to increase significantly from the prepublication to the postpublication time interval. The odds of in-hospital mortality (OR, 2.56; 95% CI, 1.17-5.62; P = .019) and postoperative in-hospital stroke (OR, 1.53; 95% CI, 1.09-3.68; P = .024) were independently and significantly higher for CAS patients in the overall sample.

CONCLUSIONS

The use of CAS for carotid revascularization in a high-risk cohort of patients has significantly increased from 2005 to 2011. Compared with CEA, CAS independently increased the odds of perioperative in-hospital stroke in all high-risk patients and of in-hospital mortality in symptomatic high-risk patients.

Carotid endarterectomy should not be based on consensus statement duplex velocity criteria

OBJECTIVE

Randomized trials support carotid endarterectomy (CEA) in asymptomatic patients with ≥60% internal carotid artery (ICA) stenosis. The widely referenced Society for Radiologists in Ultrasound Consensus Statement on carotid duplex ultrasound (CDUS) imaging indicates that an ICA peak systolic velocity (PSV) ≥230 cm/s corresponds to a ≥70% ICA stenosis, leading to the potential conclusion that asymptomatic patients with an ICA PSV ≥230 cm/s would benefit from CEA. Our goal was to determine the natural history stroke risk of asymptomatic patients who might have undergone CEA based on consensus statement PSV of ≥230 cm/s but instead were treated medically based on more conservative CDUS imaging criteria.

METHODS

All patients who underwent CDUS imaging at our institution during 2009 were retrospectively reviewed. The year 2009 was chosen to ensure extended follow-up. Asymptomatic patients were included if their ICA PSV was ≥230 cm/s but less than what our laboratory considers a ≥80% stenosis by CDUS imaging (PSV ≥430 cm/s, end-diastolic velocity ≥151 cm/s, or ICA/common carotid artery PSV ratio ≥7.5). Study end points included freedom from transient ischemic attack (TIA), freedom from any stroke, freedom from carotid-etiology stroke, and freedom from revascularization.

RESULTS

Criteria for review were met by 327 patients. Mean follow-up was 4.3 years, with 85% of patients having >3-year follow-up. Four unheralded strokes occurred during follow-up at <1, 17, 25, and 30 months that were potentially attributable to the index carotid artery. Ipsilateral TIA occurred in 17 patients. An additional 12 strokes occurred that appeared unrelated to ipsilateral carotid disease, including hemorrhagic events, contralateral, and cerebellar strokes. Revascularization was undertaken in 59 patients, 1 for stroke, 12 for TIA, and 46 for asymptomatic disease. Actuarial freedom from carotid-etiology stroke was 99.7%, 98.4%, and 98.4% at 1, 3, and 5 years, respectively. Freedom from TIA was 98%, 96%, and 95%, freedom from any stroke was 99%, 96%, and 93%, and freedom from revascularization was 95%, 86%, and 81% at 1, 3, and 5 years, respectively.

CONCLUSIONS

Patients with intermediate asymptomatic carotid stenosis (ICA PSV 230-429 cm/s) do well with medical therapy when carefully monitored and intervened upon using conservative CDUS criteria. Furthermore, a substantial number of patients would undergo unnecessary CEA if consensus statement CDUS thresholds are used to recommend surgery. Current velocity threshold recommendations should be re-evaluated, with potentially important implications for upcoming clinical trials.

Effect of Carotid Revascularization Endarterectomy Versus Stenting Trial Results on the Performance of Carotid Artery Stent Placement and Carotid Endarterectomy in the United States

BACKGROUND

CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial) results, published in 2010, showed no difference in the rates of composite outcome (stroke, myocardial infarction, or death) between carotid artery stent placement (CAS) and carotid endarterectomy (CEA).

OBJECTIVE

To identify any changes in use and outcomes of CAS and CEA subsequent to the CREST results.

METHODS

We estimated the frequency of CAS and CEA procedures in the years 2009 (pre-CREST period) and 2011 (post-CREST period), using data from the National Inpatient Sample (NIS). Demographic and clinical characteristics and in-hospital outcomes of pre- and post-CREST CAS-treated and post-CREST CEA-treated patients were compared with pre-CREST CEA-treated patients.

RESULTS

A total of 225,191 patients underwent CEA or CAS in the pre- and post-CREST periods. The frequency of CAS among carotid revascularization procedures did not change after publication of the CREST results (12.3% vs. 12.7%, P = .9). In the pre-CREST period, the CAS group (compared with the CEA group) had higher rates of congestive heart failure (P < .001), coronary artery disease (P < .001), and renal failure (P < .001). The post-CREST CAS group had a higher frequency of atrial fibrillation (P = .003), congestive heart failure (P < .0001), coronary artery disease (P < .0001), and renal failure (P = .0001). Discharge with moderate to severe disability (P < .0001) and postprocedure neurological complications (P = .005) were more frequently reported in the post-CREST CAS group. After adjusting for age, sex, and risk factors, the odds ratio (OR) for moderate to severe disability was 1.0 (95% confidence interval [CI]: 0.8-1.2) in the pre-CREST CAS group and 1.4 (95% CI: 1.1-1.7) in the post-CREST CAS group compared with the reference group. The adjusted OR for neurological complications in the pre-CREST CAS group was 1.6 (95% CI: 1.2-2.1, P = .002), and 1.5 (95% CI: 1.1-2.0, P = .01) in the post-CREST CAS group.

CONCLUSION

The frequency of CAS and CEA for carotid artery stenosis has not changed after publication of the CREST. The demographics, pretreatment comorbidity profile, and in-hospital complication rates remained unchanged during the 2 time periods.

Primary Angioplasty Versus Stenting for Endovascular Management of Intracranial Atherosclerotic Disease Following Acute Ischemic Stroke

BACKGROUND

The future of neuroendovascular treatment for intracranial atherosclerotic disease (ICAD) has been debated since the results of SAMMPRIS reflected poor outcomes following endovascular therapy. There is currently a large spectrum of current management strategies. We compared historical outcomes of patients with ICAD and stroke that were treated with angioplasty-alone versus stent placement.

METHODS

We extracted a population from the Nationwide Inpatient Sample (NIS) (2005-2011) and the National Inpatient Sample (NIS) (2012) composed of patients with ICAD and infarction that were admitted nonelectively and received endovascular revascularization. Patients treated with thrombectomy or thrombolysis were excluded. Categorical variables were compared with Chi-squared tests. Binary logistic regression was performed to evaluate mortality while controlling for age, sex, severity, and comorbidities.

RESULTS

About 2059 admissions met our criteria. A majority were treated via stent placement (71%). Angioplasty-alone had significantly higher mortality (17.6% vs. 8.4%, P<0.001), but no difference in iatrogenic stroke rate (3.4% vs. 3.6%, P=0.826), compared to stent placement. The adjusted odds ratio of mortality for stented patients was 0.536 (95% CI: 0.381-0.753, P<0.001) in comparison to patients treated with angioplasty alone.

CONCLUSIONS

This study found the risk of mortality to be elevated following angioplasty alone in comparison to revascularization with stent placement, without a corresponding significant difference in iatrogenic stroke rate. This may represent selection bias due to patient characteristics not defined in the database, but it also may indicate that patients with ICAD and acute stroke have increased odds of stenosis that is refractory to angioplasty alone and have a high risk of mortality without revascularization.

Trends, Predictors, and Outcomes of Stroke After Surgical Aortic Valve Replacement in the United States

BACKGROUND

Postoperative stroke is a devastating complication after aortic valve replacement (AVR). Our objective was to use a large national database to identify the incidence of and risk factors for stroke after AVR, as well as to determine incremental mortality, resource use, and cost of stroke.

METHODS

We identified 360,437 patients who underwent isolated surgical AVR between 1998 and 2011 from the National Inpatient Sample (NIH) database. Mean age was 66 ± 32 years. Multivariable regression and propensity matching were used to identify risk factors and the effect of stroke on outcomes. Patients were stratified according to the Elixhauser comorbidity score (ECS) into low- (0-5), medium- (6-15), and high-risk (16+) categories.

RESULTS

Stroke after AVR occurred in 5,092 (1.45%) patients. The incidence of stroke declined from 1.69% in 1999 to 0.94% in 2011 (p < 0.001). Increasing age and higher comorbidities were the main predictors of stroke (each p < 0.001). The highest-volume centers (>200 AVRs/y) had the lowest rate of stroke (1.2%). After multivariable adjustment, high-volume centers had lower odds of stroke in medium-risk (odds ratio [OR], 0.59; 95% confidence interval [CI], 0.37-0.94) and high-risk patients (OR, 0.39; 95% CI, 0.22-0.68) compared with the lowest-volume centers. For low-risk patients, volume was not associated with stroke. Patients who experienced stroke were hospitalized for 4 days longer, had an average of $10,496 higher costs, and had 2.74 (95% CI, 1.97-3.80) times higher odds of in-hospital mortality compared with those who did not experience stroke (all p < 0.001).

CONCLUSIONS

The incidence of stroke after AVR has decreased but remains a significant cause of morbidity in medium- and high-risk patients. Superior outcomes can be achieved in medium- to high-risk patients at high-volume centers.

[Treatment reality of internal carotid artery stenosis in Germany : requirement and reality in international comparison and in light of the current S3 guidelines]

BACKGROUND

Severe atherosclerotic extracranial carotid artery stenosis accounts for 5-10 % of all ischemic strokes. Currently, therapeutic recommendations are undergoing changes, particularly regarding the treatment of asymptomatic stenosis. Consolidated knowledge on the indications, nationwide distribution and numbers of cases are not available. Moreover, the impact and grade of implementation of the recently published national S3 guidelines on the reality of medical treatment remain unclear.

METHODS

Analysis of administrative hospital data involving the diagnosis-related groups (DRG) statistics and structured quality reports for 2010 and 2013 to evaluate the procedural therapy trends concerning operative and interventional approaches for symptomatic and asymptomatic carotid artery stenoses.

RESULTS

In Germany approximately 37,000 carotid endarterectomies (CEA) and approximately 5,000 carotid angioplasties with stenting (CAS) are carried out per year. Approximately 94 % of CEA and 62 % of CAS are performed in centers with more than 25 procedures per year. Only 33 % of CEA and 39 % of CAS are related to symptomatic stenosis.

CONCLUSION

Mathematically, an undertreatment of symptomatic and an overtreatment of asymptomatic carotid artery stenoses become apparent. Efforts should be made to achieve inpatient medical treatment conforming to the national S3 guidelines, in particular to adequately reduce the risk of stroke recurrence in patients with atherosclerotic symptomatic carotid artery stenosis.

The Association of Publication of Center for Medicaid and Medicare Services Guidelines for Carotid Artery Angioplasty and Stenting (CAS) and CREST Results on the Utilization of CAS in Carotid Revascularization

BACKGROUND

Since the 2004 approval of carotid artery angioplasty and stenting (CAS), there have been 2 seminal publications about CAS reimbursement (Center for Medicaid and Medicare Several guidelines [CMSG]; 2008) and clinical outcomes (Carotid Revascularization Endarterectomy versus Stent Trial [CREST]; 2010). We explored trends in CAS utilization after these publications nationally.

METHODS

The most recent datasets of the nationwide inpatient sample (NIS) was queried for patients undergoing carotid revascularization. Utilization proportions of CAS were calculated quarterly from 2005 to 2011 for NIS. Three-time intervals related to CMSG and CREST publication were selected 2005-2008, 2008-2010, and after 2010. Logistic regression with piecewise linear trend for time was used to estimate different trends in CAS utilization for overall samples and for neurologically asymptomatic and symptomatic cases.

RESULTS

The majority (95%) of the carotid revascularizations were performed on asymptomatic patients. Overall, CAS utilization constituted 12.5% of carotid revascularization procedures with a significant period increase of CAS; from 9.4% to 14%; P < 0.001. There was a small but significant decrease in the rate of CAS utilization after CMSG were published corresponding to a 2% decline in the odds ratio (OR) of CAS per quarter (OR, 0.98; 95% confidence interval, 0.97-0.99; P = 0.001). After CREST, CAS utilization continued to increase in both NIS but the rate of increase did not change significantly from the prepublication to the postpublication time interval. The odds of in-hospital mortality and postoperative stroke were independently and significantly higher for CAS patients in both overall and within the symptomatic cohorts. In all 3 periods of the study, and compared to carotid endarterectomy, the odds of mortality and postoperative stroke were significantly higher among patients who underwent CAS.

CONCLUSIONS

Although overall utilization of CAS increased since 2005, it was not uniformly associated by the publication of CMSG or CREST. Despite increased utilization, the odds of adverse outcomes were independently higher among CAS patients.

Rates and predictors of 5-year survival in a national cohort of asymptomatic elderly patients undergoing carotid revascularization

BACKGROUND

Current American Heart Association guidelines recommend carotid revascularization for asymptomatic patients on the basis of life expectancy.

OBJECTIVE

To determine the rates and predictors of 5-year survival in elderly patients with asymptomatic carotid artery stenosis who underwent either carotid artery stent placement (CAS) or carotid endarterectomy (CEA).

METHODS

The rates of 5-year survival were determined by use of Kaplan-Meier survival methods in a representative sample of fee-for-service Medicare beneficiaries ≥65 years of age who underwent CAS or CEA for asymptomatic carotid artery stenosis with postprocedural follow-up of 3.4 ± 1.7 years. Cox proportional hazards analysis was used to assess the relative risk of all-cause mortality for patients in the presence of selected comorbidities, including ischemic heart disease, chronic renal failure, and atrial fibrillation, after adjustment for potential confounders such as age, sex, race/ethnicity, and procedure type.

RESULTS

A total of 22,177 patients with asymptomatic carotid artery stenosis were treated with either CAS (n = 2144) or CEA (n = 20,033). The overall estimated 5-year survival rate (±SE) was 95.3 ± 0.00149; it was 95.5% and 93.8% in patients treated with CEA and CAS, respectively. After adjustment for potential confounders, relative risk of all-cause 5-year mortality was significantly higher among patients with atrial fibrillation (relative risk, 1.8; 95% confidence interval, 1.5-2.1) and those with chronic renal failure (relative risk, 2.1; 95% confidence interval, 1.7-2.6).

CONCLUSION

Risks and benefits must be carefully weighed before carotid revascularization in elderly patients with asymptomatic carotid artery stenosis who have concurrent atrial fibrillation or chronic renal failure.

Correlation of Carotid Intraplaque Hemorrhage and Stroke Using 1.5 T and 3 T MRI

Carotid therosclerotic disease causes approximately 25% of the nearly 690,000 ischemic strokes each year in the United States. Current risk stratification based on percent stenosis does not provide specific information on the actual risk of stroke for most individuals. Prospective randomized studies have found only 10 to 12% of asymptomatic patients will have a symptomatic stroke within 5 years. Measurements of percent stenosis do not determine plaque stability or composition. Reports have concluded that cerebral ischemic events associated with carotid plaque are intimately associated with plaque instability. Analysis of retrospective studies has found that plaque composition is important in risk stratification. Only MRI has the ability to identify and measure the detailed components and morphology of carotid plaque and provides more detailed information than other currently available techniques. MRI can accurately detect carotid hemorrhage, and MRI identified carotid hemorrhage correlates with acute stroke.

Mortality of acute mesenteric ischemia remains unchanged despite significant increase in utilization of endovascular techniques

Introduction

In this study, we evaluated if increase in utilization of endovascular surgery has affected in-hospital mortality rates among patients with acute mesenteric ischemia.

Methods

The National Inpatient Sample (2003–2011) was queried for acute mesenteric ischemia using ICD-9 code for acute mesenteric ischemia (557.1). This cohort was divided into patients treated with open vascular surgery (open vascular group) and by endovascular therapies (endovascular group) based on the ICD-9CM procedure codes. Multivariable logistic regression was used to determine temporal trend for mortality while adjusting for confounding variables.

Results

There was 1.45-fold increase in utilization of endovascular techniques in this study. In-hospital mortality rate, total median charges and length of stay were significantly lower among the endovascular group than the open vascular group despite having significantly higher Elixhauser comorbidities index (3 ± 0.1 vs. 2.7 ± 0.1, p = .003). Over the course of the study period, there was no change in the overall mortality rate despite higher endovascular utilization. Factors associated with increased mortality included age, open surgical repair (Odds ratio: 1.45, 95% Confidence Interval: 1.10–1.91, p = .016) and bowel resection Odds ratio: 2.88, 95% Confidence Interval: 2.01–4.12).

Conclusion

The mortality rate for acute mesenteric ischemia remains unchanged throughout this contemporary study. Open surgical intervention, bowel resection and age were associated with increased mortality. Endovascular group patients had better survival despite higher morbidity indices.

Guidelines for the primary prevention of stroke: a statement for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of stroke among individuals who have not previously experienced a stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches to atherosclerotic disease of the cervicocephalic circulation, and antithrombotic treatments for preventing thrombotic and thromboembolic stroke. Further recommendations are provided for genetic and pharmacogenetic testing and for the prevention of stroke in a variety of other specific circumstances, including sickle cell disease and patent foramen ovale.

Why is the management of asymptomatic carotid disease so controversial?

BACKGROUND

Despite level I evidence supporting a role for carotid endarterectomy (CEA) in the management of patients with asymptomatic carotid disease, there is surprisingly little international consensus regarding the optimal way to manage these patients.

METHODS

Review of current strategies for managing asymptomatic carotid disease

MAIN FINDINGS

Those favouring a pro-interventional approach argue that: (i) until new randomised trials demonstrate that best medical therapy (BMT) is better than CEA or carotid artery stenting (CAS) in preventing stroke, guidelines of practice should remain unchanged; (ii) strokes secondary to carotid thromboembolism harboured a potentially treatable asymptomatic lesion prior to the event. Because 80% of strokes are not preceded by a TIA/minor stroke, CEA/CAS is the only way of preventing these strokes; (iii) screening for carotid disease could identify patients with significant asymptomatic stenoses who could undergo prophylactic CEA/CAS in order to prevent avoidable stroke; (iv) international guidelines already advise that only 'highly-selected' patients should undergo CEA/CAS; (v) the 30-day risks of death/stroke after CEA/CAS are diminishing and this will increase long-term stroke prevention and (vi) the alleged decline in annualized stroke rates in medically treated patients is based upon flawed data.

CONCLUSIONS

The inescapable conclusion is that only a relatively small proportion of asymptomatic patients benefit from prophylactic CEA/CAS. The key question, therefore, remains; is society prepared to invest sufficient resources in identifying these 'high risk for stroke' patients so that they can benefit from aggressive BMT and CEA or CAS, leaving the majority of lower risk patients to be treated medically?