Operator experience and carotid stenting outcomes in Medicare beneficiaries

Association between Asian race and perioperative outcomes after carotid revascularization varies with Asian procedure density

OBJECTIVE

Postoperative outcomes following carotid revascularization are understudied in Asian patients. We aimed to assess whether disease severity and postoperative outcomes following carotid revascularization differ between Asian and White patients, and whether this varies with Asian procedure density.

METHODS

We analyzed the Vascular Quality Initiative Carotid Endarterectomy and Carotid Artery Stenting datasets from 2003 to 2021. Regions were divided into tertiles based on Asian procedure density. Propensity scores were used to match Asian and White patients based on patient factors and procedure type. The primary outcome variable was a collapsed composite of in-hospital ipsilateral stroke/death/myocardial infarction. χ2 tests were used to assess association between Asian race and disease severity, center and surgeon volume, and 1-year outcomes. Logistic and Cox regressions were performed between the matched cohorts.

RESULTS

A total of 1766 Asian and 159,608 White patients underwent carotid revascularization, and we identified 2704 patients (1352 Asian and 1352 White) in the matched cohorts. Among propensity matched patients, all-comer Asian patients more commonly had >80% ipsilateral stenosis (63% vs 52%; P < .001) and a moderate/severe preoperative Rankin score (7.6% vs 5.1%; P = .007). The rate of in-hospital stroke/death/myocardial infarction was higher in Asian patients (2.6% vs 1.3%; P = .012), and this disparity was more pronounced in the lowest tertile of Asian procedure density (4.3% vs 0.5%; P < .001). Logistic regression in the propensity-matched cohort demonstrated Asian race was associated with lower odds of intervention at highest volume centers (odds ratio [OR], 0.3; 95% confidence interval [CI], 0.2-0.3; P < .001) and by highest volume surgeons (OR, 0.3; 95% CI, 0.3-0.4; P < .001). Asian race was associated with higher odds of in-hospital stroke/death/myocardial infarction (OR, 2.0; 95% CI, 1.1-3.8; P = .031), and there was a significant interaction between Asian procedure density and the relationship between Asian race and this outcome (interaction P = .001). After accounting for center and surgeon volume, the association of Asian race and the composite outcome was mitigated (OR, 1.5; 95% CI, 0.7-3.3; P = .300). Cox regression between the matched cohorts demonstrated that Asian race was associated with lower 1-year mortality (hazard ratio, 0.5; 95% CI, 0.3-0.7; P = .001) and higher risk of 1-year reintervention (hazard ratio, 16; 95% CI, 1.8-142; P = .013).

CONCLUSIONS

Asian patients are more likely to present with a higher degree of carotid stenosis, higher preoperative risk, and experience worse perioperative outcomes. The association of Asian race with perioperative stroke/death/myocardial infarction varies with Asian procedure density and is also confounded by center and surgeon volume. These results highlight the importance of understanding referral patterns and cultural effects on outcomes disparities in Asian patients.

Implications of the Centers for Medicare and Medicaid Services decision to expand indications for carotid artery stenting

OBJECTIVE

On October 11, 2023, the Centers for Medicare and Medicaid Services (CMS) expanded the indications for carotid artery stenting (CAS) to include patients with ≥50% symptomatic or ≥70% asymptomatic carotid stenosis. The aim of this article was to investigate the implications of this decision.

METHODS

The reasons behind the increased coverage for CAS are analyzed and discussed, as well as the various Societies supporting or opposing the expansion of indications for CAS.

RESULTS

The benefits associated with expanding CAS indications include providing an additional therapeutic option to patients and enabling individualization of treatment according to patient-specific characteristics. The drawbacks of expanding CAS indications include a possible bias in decision-making and an increase in inappropriate CAS procedures.

CONCLUSIONS

The purpose of the CMS recommendation to expand indications for CAS is to improve the available therapeutic options for patients. Hopefully this decision will not be misinterpreted and will be used to improve patient options and patient outcomes.

Derivation and Validation of ICD-10 Codes for Identifying Incident Stroke

Importance

Claims data with International Statistical Classification of Diseases, Tenth Revision (ICD-10) codes are routinely used in clinical research. However, the use of ICD-10 codes to define incident stroke has not been validated against expert-adjudicated outcomes in the US population.

Objective

To develop and validate the accuracy of an ICD-10 code list to detect incident stroke events using Medicare inpatient fee-for-service claims data.

Design, Setting, and Participants

This cohort study used data from 2 prospective population-based cohort studies, the Atherosclerosis Risk in Communities (ARIC) study and the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, and included participants aged 65 years or older without prior stroke who had linked Medicare claims data. Stroke events in the ARIC and REGARDS studies were identified via active surveillance and adjudicated by expert review. Medicare-linked ARIC data (2016-2018) were used to develop a list of ICD-10 codes for incident stroke detection. The list was validated using Medicare-linked REGARDS data (2016-2019). Data were analyzed from September 1, 2022, through September 30, 2023.

Exposures

Stroke events detected in Medicare claims vs expert-adjudicated stroke events in the ARIC and REGARDS studies.

Main Outcomes and Measures

The main outcomes were sensitivity and specificity of incident stroke detection using ICD-10 codes.

Results

In the ARIC study, there were 110 adjudicated incident stroke events among 5194 participants (mean [SD] age, 80.1 [5.3] years) over a median follow-up of 3.0 (range, 0.003-3.0) years. Most ARIC participants were women (3160 [60.8%]); 993 (19.1%) were Black and 4180 (80.5%) were White. Using the primary diagnosis code on a Medicare billing claim, the ICD-10 code list had a sensitivity of 81.8% (95% CI, 73.3%-88.5%) and a specificity of 99.1% (95% CI, 98.8%-99.3%) to detect incident stroke. Using any diagnosis code on a Medicare billing claim, the sensitivity was 94.5% (95% CI, 88.5%-98.0%) and the specificity was 98.4% (95% CI, 98.0%-98.8%). In the REGARDS study, there were 140 adjudicated incident strokes among 6359 participants (mean [SD] age, 75.8 [7.0] years) over a median follow-up of 4.0 (range, 0-4.0) years. More than half of the REGARDS participants were women (3351 [52.7%]); 1774 (27.9%) were Black and 4585 (72.1%) were White. For the primary diagnosis code, the ICD-10 code list had a sensitivity of 70.7% (95% CI, 63.2%-78.3%) and a specificity of 99.1% (95% CI, 98.9%-99.4%). For any diagnosis code, the ICD-10 code list had a sensitivity of 77.9% (95% CI, 71.0%-84.7%) and a specificity of 98.9% (95% CI, 98.6%-99.2%).

Conclusions and Relevance

These findings suggest that ICD-10 codes could be used to identify incident stroke events in Medicare claims with moderate sensitivity and high specificity.

Higher stroke risk after carotid endarterectomy and transcarotid artery revascularization is associated with relative surgeon volume ratio

OBJECTIVE

Adoption of transcarotid artery revascularization (TCAR) by surgeons has been variable, with some still performing traditional carotid endarterectomy (CEA), whereas others have shifted to mostly TCAR. Our goal was to evaluate the association of relative surgeon volume of CEA to TCAR with perioperative outcomes.

METHODS

The Vascular Quality Initiative CEA and carotid artery stent registries were analyzed from 2021 to 2023 for symptomatic and asymptomatic interventions. Surgeons participating in both registries were categorized in the following CEA to CEA+TCAR volume percentage ratios: 0.25 (majority TCAR), 0.26 to 0.50 (more TCAR), 0.51 to 0.75 (more CEA), and 0.76 to 1.00 (majority CEA). Primary outcomes were rates of perioperative ipsilateral stroke, death, cranial nerve injury, and return to the operating room for bleeding.

RESULTS

There were 50,189 patients who underwent primary carotid revascularization (64.3% CEA and 35.7% TCAR). CEA patients were younger (71.1 vs 73.5 years, P < .001), with more symptomatic cases, less coronary artery disease, diabetes, and lower antiplatelet and statin use (all P < .001). TCAR patients had lower rates of smoking, obesity, and dialysis or renal transplant (all P < .001). Postoperative stroke after CEA was significantly impacted by the operator CEA to TCAR volume ratio (P = .04), with surgeons who perform majority TCAR and more TCAR having higher postoperative ipsilateral stroke (majority TCAR odds ratio [OR]: 2.15, 95% confidence interval [CI]: 1.16-3.96, P = .01; more TCAR OR: 1.42, 95% CI: 1.02-1.96, P = .04), as compared with those who perform majority CEA. Similarly, postoperative stroke after TCAR was significantly impacted by the CEA to TCAR volume ratio (P = .02), with surgeons who perform majority CEA and more CEA having higher stroke (majority CEA OR: 1.51, 95% CI: 1.00-2.27, P = .05; more CEA OR: 1.50, 95% CI: 1.14-2.00, P = .004), as compared with those who perform majority TCAR. There was no association between surgeon ratio and perioperative death, cranial nerve injury, and return to the operating room for bleeding for either procedure.

CONCLUSIONS

The relative surgeon CEA to TCAR ratio is significantly associated with perioperative stroke rate. Surgeons who perform a majority of one procedure have a higher stroke rate in the other. Surgeons offering both operations should maintain a balanced practice and have a low threshold to collaborate as needed.

Socioeconomic status as a predictor of post-operative mortality and outcomes in carotid artery stenting vs. carotid endarterectomy

Background

The association between low socioeconomic status (SES) and worse surgical outcomes has become an emerging area of interest. Literature has demonstrated that carotid artery stenting (CAS) poses greater risk of postoperative complications, particularly stroke, than carotid endarterectomy (CEA). This study aims to compare the impact of low SES on patients undergoing CAS vs. CEA.

Methods

The National Inpatient Sample (NIS) was queried for patients undergoing CAS and CEA from 2010 to 2015. Patients were stratified by highest and lowest median income quartiles by zip code and compared through demographics, hospital characteristics, and comorbidities defined by the Charlson Comorbidity Index (CCI). Primary outcome was in-hospital mortality. Secondary outcomes included acute kidney injury (AKI), post-operative stroke, sepsis, and bleeding requiring reoperation.Multivariable logistic regression was used to determine the effect of SES on outcomes.

Results

Five thousand four hundred twenty-five patients underwent CAS (Low SES: 3,516 (64.8%); High SES: 1,909 (35.2%) and 38,399 patients underwent CEA (Low SES: 22,852 (59.5%); High SES: 15,547 (40.5%). Low SES was a significant independent predictor of mortality [OR = 2.07 (1.25-3.53); p = 0.005] for CEA patients, but not for CAS patients [OR = 1.21 (CI 0.51-2.30); p = 0.68]. Stroke was strongly associated with low SES, CEA patients (Low SES = 1.5% vs. High SES = 1.2%; p = 0.03), while bleeding was with high SES, CAS patients (Low SES = 5.3% vs. High SES = 7.1%; p = 0.01). CCI was a strong predictor of mortality for both procedures [CAS: OR1.45 (1.17-1.80); p < 0.001. CEA: OR1.60 (1.45-1.77); p < 0.001]. Advanced age was a predictor of mortality post-CEA [OR = 1.03 (1.01-1.06); p = 0.01]. While not statistically significant, advanced age and increased mortality trended towards a positive association in CAS [OR = 1.05 (1.00-1.10); p = 0.05].

Conclusions

Low SES is a significant independent predictor of post-operative mortality in patients who underwent CEA, but not CAS. CEA is also associated with higher incidence of stroke in low SES patients. Findings demonstrate the impact of SES on outcomes for patients undergoing carotid revascularization procedures. Prospective studies are warranted to further evaluate this disparity.

Carotid Artery Stenting Versus Carotid Artery Endarterectomy in Asymptomatic Severe Carotid Stenosis: An Updated Meta-Analysis

Carotid artery stenting (CAS) and carotid artery endarterectomy (CEA) are revascularization options for the management of severe carotid disease in asymptomatic patients. We aimed to compare the peri-procedural outcomes of the two modalities. A systematic review of the databases PUBMED, EBSCO, and Cochrane Library was performed. All the studies that reported periprocedural outcomes (within 30 days) in asymptomatic carotid stenosis patients were included in the meta-analysis. Random effects models with inverse-variance weighting were used to estimate pooled risk ratios (RRs) to compare the outcomes. Fifteen studies (including seven randomized controlled trials) met the inclusion criteria. A total of 15251 patients were included, out of which 6419 (42%) underwent CAS and 8832 (57.9%) underwent CEA. There was no statistical difference in the primary composite outcome of death/stroke/myocardial infarction (MI) (RR 1.02, 95% CI [0.69-1.51], p 0.93). No difference was found in the secondary outcome of all-cause mortality. CAS was associated with a slightly lower risk of MI and cranial nerve palsy. CAS was associated with a slightly higher risk of stroke with no difference in the occurrence of disabling stroke or ipsilateral stroke. In general terms, the study confirms equipoise in the two treatment strategies with a higher risk of MI and cranial nerve palsy with CEA and a higher risk of non-disabling stroke with CAS.

Simulating complex patient populations with hierarchical learning effects to support methods development for post-market surveillance

BACKGROUND

Validating new algorithms, such as methods to disentangle intrinsic treatment risk from risk associated with experiential learning of novel treatments, often requires knowing the ground truth for data characteristics under investigation. Since the ground truth is inaccessible in real world data, simulation studies using synthetic datasets that mimic complex clinical environments are essential. We describe and evaluate a generalizable framework for injecting hierarchical learning effects within a robust data generation process that incorporates the magnitude of intrinsic risk and accounts for known critical elements in clinical data relationships.

METHODS

We present a multi-step data generating process with customizable options and flexible modules to support a variety of simulation requirements. Synthetic patients with nonlinear and correlated features are assigned to provider and institution case series. The probability of treatment and outcome assignment are associated with patient features based on user definitions. Risk due to experiential learning by providers and/or institutions when novel treatments are introduced is injected at various speeds and magnitudes. To further reflect real-world complexity, users can request missing values and omitted variables. We illustrate an implementation of our method in a case study using MIMIC-III data for reference patient feature distributions.

RESULTS

Realized data characteristics in the simulated data reflected specified values. Apparent deviations in treatment effects and feature distributions, though not statistically significant, were most common in small datasets (n < 3000) and attributable to random noise and variability in estimating realized values in small samples. When learning effects were specified, synthetic datasets exhibited changes in the probability of an adverse outcomes as cases accrued for the treatment group impacted by learning and stable probabilities as cases accrued for the treatment group not affected by learning.

CONCLUSIONS

Our framework extends clinical data simulation techniques beyond generation of patient features to incorporate hierarchical learning effects. This enables the complex simulation studies required to develop and rigorously test algorithms developed to disentangle treatment safety signals from the effects of experiential learning. By supporting such efforts, this work can help identify training opportunities, avoid unwarranted restriction of access to medical advances, and hasten treatment improvements.

Age and Five-Year Outcomes After Carotid Artery Stenting in Symptomatic Carotid Stenosis: A Retrospective Cohort Study

Background

Several clinical trials have reported that periprocedural risk of carotid artery stenting (CAS) increase with age. China is experiencing one of the most rapid transitions to an aging society, while the clinical outcomes of CAS in real-world China are still limited. The study aimed to compare the periprocedural and an extending 5-year event rates between younger and older patients treated by CAS to testify the safety of CAS in older patients in China.

Methods

This is a single center, retrospective cohort study. Symptomatic patients who underwent CAS from Nov 2011 to June 2014 were retrospectively included in this study, The population was divided into two age groups: <70 and ≥70. The main primary endpoint was stroke, myocardial infarction or death occurring at 30 days, or ipsilateral stroke over 5-year after stenting.

Results

A total of 103 symptomatic patients (<70: 68%; ≥70: 32%) with CAS included in the study. During the 30-day period, the rate of primary outcome was 1.0% with only one stroke in patients younger than 70 years old ( P = 1.000). After five years, the rate of primary outcome was low (10.9%, 10/92) despite some of the patients had major stroke or underwent bilateral C1 stenting. There was no significant difference in the 5-year rates of the primary outcome between the young and old groups (12.3% vs 7.4%, P = .718). Kaplan-Meier estimates of the proportion of study participants with a primary endpoint showed that there was no significant age-dependent difference of the stroke and death outcome in symptomatic patients.

Conclusions

Age (<70 vs ≥ 70) had no influence on the risk of stroke or death in symptomatic patients either in the short or long term. CAS is an optimal treatment for older patients with cervical carotid artery stenosis, and CAS was safe for those with major stroke or bilateral C1 stenting.

Learning curve and proficiency metrics for transcarotid artery revascularization

BACKGROUND

When introduced to a new procedure, physicians improve their performance and reduce their procedural adverse event rates rapidly during the initial cases and then improvement slows, signaling that proficiency has been achieved. Determining when they have acquired proficiency has important implications for procedural innovation, education, credentialing, and patient safety. We analyzed the worldwide experience with transcarotid artery revascularization (TCAR), a hybrid approach to carotid revascularization, to identify the (1) procedural performance measures associated with clinical and technical adverse events; (2) target levels of performance measures that minimize adverse event rates; and (3) number of TCAR cases needed to achieve the target levels for the performance measures.

METHODS

The patient, lesion, and physician characteristics were collected for each TCAR procedure performed by each physician worldwide in an international quality assurance database. Four procedural performance measures were recorded for each procedure: flow-reversal time, fluoroscopy time, contrast volume, and total skin-to-skin time. Composite clinical adverse events (ie, transient ischemic attack, stroke, myocardial infarction, death) and composite technical adverse events (ie, aborted procedure, conversion to surgery, bleeding, dissection, cranial nerve injury, device failure), occurring within 24 hours were also recorded. Correlations between each performance measure and the clinical and technical adverse event rates were computed. The inflection points in the performance measures were identified at which no further improvements occurred in the adverse event rates. Finally, the minimum number of TCAR cases required to achieve the target performance measure levels was computed.

RESULTS

A total of 18,240 procedures performed by 1273 physicians were analyzed. Of the 18,240 patients, 34.9% were women and 62.5% were asymptomatic. The flow-reversal time correlated with clinical adverse events adjusted for age, sex, and symptomatic status (R2 = 0.91; P < .0001) and adjusted technical adverse events (R2 = 0.86; P < .0001). The skin-to-skin time correlated with adjusted technical adverse events (R2 = 0.92; P < .0001). A reduction in flow-reversal times to <13.1 minutes and the skin-to-skin time to <81 minutes did not translate into further improvements in the adverse event rates. A minimum of 26 TCAR cases was required to achieve the target flow-reversal time, and a minimum of 15 cases was required to achieve the target skin-to-skin time.

CONCLUSIONS

The flow-reversal time and skin-to-skin time are appropriate performance measures for establishing the level of expertise of physicians as they acquire skills to perform TCAR. A target time of ≤13.1 minutes for flow-reversal and 81 minutes for skin-to-skin time minimized the adverse event rates. Familiarity with the steps involved in performing TCAR was achieved after ≥15 cases, and minimizing clinical adverse events occurred after ≥26 cases.

Management of Atherosclerotic Carotid Artery Disease: A Brief Overview and Update

Extracranial carotid atherosclerotic disease has been associated with approximately 15%-20% of ischemic stroke cases and is a leading cause of mortality and disability worldwide. Medical, surgical, and endovascular therapies for the prevention of stroke from carotid disease have advanced considerably over the past quarter century. The objective of this review is to outline the clinical presentation of symptomatic carotid artery stenosis and the risk factors associated with development of carotid artery stenosis and then summarize the current evidence-based medical treatment modalities, along with available surgical and endovascular therapies.

Characteristics and outcomes of elderly patients undergoing carotid stenting: Experience of a high-volume interventional cardiology center

BACKGROUND

Carotid artery stenting (CAS) is an attractive option in order to treat carotid artery stenosis. However, its safety in elderly patients is questioned. Aim of this single-center retrospective study was to assess data of elderly patients undergoing CAS, and to compare them with those of the younger (< 75 years).

METHODS

We collected data of 580 consecutive patients undergoing CAS between December 2007 and June 2020 and compared clinical and procedural characteristics as well as in-hospital major adverse events (MACCE) and long-term mortality between patients < 75 years and patients ≥ 75 years old.

RESULTS

There were 272 patients (46.9%) with age ≥ 75 years and 308 patients (53.1%) with age < 75 years. The median follow-up was 48 months (range 2-144). There was no significant difference about in-hospital MACCE between the two groups (4.7% in the older vs. 3.5% in the younger group, p = 0.9), but a higher rate of cerebral hemorrhage occurred in the older group (1.8% vs. = 0.3%, p = 0.07), even if not significant. Long-term mortality was significantly higher in the older group (27.9 vs. 20.1%, p = 0.027). Multivariate predictors of 12-months mortality were neurologic symptoms within 6 months (OR: 4.83; 95% CI: 2.04-11.42; p ≤ 0.001), smoking status (OR: 2.84; 95% CI: 1.17-6.86; p = 0.02) and age ≥ 75 years (OR: 2.78; 95% CI: 1.14-6.76; p = 0.024).

CONCLUSIONS

In elderly patients, CAS can be carried out efficaciously with acceptable procedural risks, if performed by expert operators and after a correct selection by a multidisciplinary team.

Point-of-care 3D printing: a low-cost approach to teaching carotid artery stenting

BACKGROUND

Carotid Artery Stenting (CAS) is increasingly being used in selected patients as a minimal invasive approach to carotid endarterectomy. Despite the long standing tradition of endovascular treatments, visual feedback during stent-deployment is impossible to obtain as deployment is performed under fluoroscopic imaging. Furthermore, the concept of stent-placement is often still unclear to patients. 3D Printing allows to replicate patient-specific anatomies and deploy stents inside them to simulate procedures. As such these models are being used for endovascular training as well as patient education.

PURPOSE

To our knowledge, this study reports the first use of a low-cost patient-specific 3D printed model for teaching CAS deployment under direct visualization, without fluoroscopy.

METHODOLOGY

A CT-angiogram was segmented and converted to STL format using Mimics inPrint™ software. The carotid arteries were bilaterally truncated to fit the whole model on a Formlabs 2 printer without omitting the internal vessel diameter. Next, this model was offset using a 1 mm margin. A ridge was modelled on the original vessel anatomy which was subsequently subtracted from the offset model in order to obtain a deroofed 3D model. All vessels were truncated to facilitate post-processing, flow and guide wire placement.

RESULTS

Carotid artery stents were successfully deployed inside the vessel. The deroofing allows for clear visualization of the bottlenecks and characteristics of CAS deployment and positioning, including stent foreshortening, tapering and recoil. This low-cost 3D model provides visual insights in stent deployment and positioning, and can allow for patient-specific procedure planning.

CONCLUSIONS

The presented approach demonstrates the use of low-cost 3D Printed CAS models in teaching complex stent behavior as observed during deployment. Two main findings are illustrated. On one hand, the feasibility of low-cost in-hospital model production is shown. On the other hand, the teaching of CAS deployment bottlenecks at the carotid level without the need for fluoroscopic guidance, is illustrated. The observed stent characteristics as shown during deployment are difficult to assess in radiologic models. Furthermore, printing patient-specific 3D models preoperatively could possibly assist in accurate patient selection, preoperative planning, case-specific training and patient education.

Early Outcomes After Carotid Endarterectomy and Carotid Artery Stenting: A Propensity-Matched Cohort Analysis

BACKGROUND

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) represent options to treat many patients with carotid stenosis. Although randomized trial data are plentiful, estimated rates of morbidity and mortality for both CEA and CAS have varied substantially.

OBJECTIVE

To evaluate rates of adverse outcomes after CAS and CEA in a large national database.

METHODS

We analyzed 84 191 adult patients undergoing elective, nonemergent CAS (n = 81 361) or CEA (n = 2830), from 2011 to 2018, in the American College of Surgeons' National Surgical Quality Improvement Program database. Odds of adverse outcomes (30-d rates of stroke, myocardial infarction (MI), cardiac arrest, prolonged length of stay (LOS), readmission, reoperation, and mortality) were evaluated in propensity-matched (n = 2821) cohorts through logistic regression.

RESULTS

In the propensity-matched cohorts, CAS had increased odds of periprocedural stroke (odds ratio [OR] 1.97, 95% CI 1.32-2.95) and decreased odds of cardiac arrest (OR 0.33, 95% CI 0.13-0.84) and 30-d reoperation (OR 0.59, 95% CI 0.44-0.80) compared to CEA. Relative odds of MI, prolonged LOS, discharge to destination other than home, 30-d readmission, or 30-d mortality were statistically similar. In the unmatched patient population, rates of adverse outcomes with CEA were constant over time; however, for CAS, rates of stroke increased over time. In both the matched and unmatched patient cohorts, patients 70 yr and older had lower rates of post-procedural stroke with CEA, but not with CAS, compared to younger patients.

CONCLUSION

In a propensity-matched analysis of a large, prospectively collected, national, surgical database, CAS was associated with increased odds of periprocedural stroke, which increased over time. Rates of MI and death were not significantly different between the 2 procedures.

SOCIETY FOR VASCULAR SURGERY CLINICAL PRACTICE GUIDELINES FOR MANAGEMENT OF EXTRACRANIAL CEREBROVASCULAR DISEASE

Management of carotid bifurcation stenosis in stroke prevention has been the subject of extensive investigations, including multiple randomized controlled trials. The proper treatment of patients with carotid bifurcation disease is of major interest to vascular surgeons and other vascular specialists. In 2011, the Society for Vascular Surgery published guidelines for treatment of carotid artery disease. At the time, several randomized trials, comparing carotid endarterectomy (CEA) and carotid artery stenting (CAS), were published. Since that publication, several studies and a few systematic reviews comparing CEA and CAS have been published, and the role of medical management has been re-emphasized. The current publication updates and expands the 2011 guidelines with specific emphasis on five areas: is carotid endarterectomy recommended over maximal medical therapy in low risk patients; is carotid endarterectomy recommended over trans-femoral carotid artery stenting in low surgical risk patients with symptomatic carotid artery stenosis of >50%; timing of carotid Intervention in patients presenting with acute stroke; screening for carotid artery stenosis in asymptomatic patients; and optimal sequence for intervention in patients with combined carotid and coronary artery disease. A separate implementation document will address other important clinical issues in extracranial cerebrovascular disease. Recommendations are made using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) approach, as has been done with other Society for Vascular Surgery guidelines. The committee recommends CEA as the first-line treatment for symptomatic low risk surgical patients with stenosis of 50% to 99% and asymptomatic patients with stenosis of 70% to 99%. The perioperative risk of stroke and death in asymptomatic patients must be <3% to ensure benefit for the patient. In patients with recent stable stroke (modified Rankin 0-2), carotid revascularization is considered appropriate in symptomatic patients with greater than 50% stenosis and is recommended and performed as soon as the patient is neurologically stable after 48 hours but definitely before 14 days of onset of symptoms. In the general population, screening for clinically asymptomatic carotid artery stenosis in patients without cerebrovascular symptoms or significant risk factors for carotid artery disease is not recommended. In selected asymptomatic patients who are at increased risk for carotid stenosis, we suggest screening for clinically asymptomatic carotid artery stenosis as long as the patients would potentially be fit for and willing to consider carotid intervention if significant stenosis is discovered. In patients with symptomatic carotid stenosis 50-99%, who require both CEA and CABG, we suggest CEA before or concomitant with CABG to potentially reduce the risk of stroke and stroke/death. The sequencing of the intervention depends on clinical presentation and institutional experience.

Carotid stenosis, stroke, and carotid artery revascularization

Atherosclerotic disease of the carotid artery places patients at risk of ischemic stroke and consequently is a target of medical, endovascular and open surgical management. Various imaging modalities are used to characterize anatomy/severity of carotid disease and justify intervention, each having advantages and disadvantages. Carotid revascularization techniques including carotid artery stenting, carotid endarterectomy, and transcarotid artery revascularization vary in invasiveness and are not equally suitable for certain subsets of patients. As such, providing quality care for patients with carotid disease requires a multidisciplinary team of experts in clinical diagnosis, image interpretation, medical management, endovascular intervention, and surgical treatment.

The Relationship Between Carotid Revascularization Procedural Volume and Perioperative Outcomes in Australia and New Zealand

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) prevent stroke in selected patients. However, each intervention carries a risk of perioperative complications including stroke or death (S/D). We aimed to determine the relationship between operator volume, hospital volume, and the perioperative risk of S/D in carotid revascularization in Australia and New Zealand. Retrospective analysis was performed on prospectively collected data extracted from the Australasian Vascular Audit between 2010 and 2017. Annual caseload volume was analyzed in quintiles (Q) using multivariate regression to assess its impact on perioperative S/D. Carotid endarterectomy procedures (n = 16 765) demonstrated higher S/D rates for lower-volume operators (2.21% for Q1-Q3 [1-17 annual cases] vs 1.76% for Q4-Q5 [18-61 annual cases]; odds ratio [OR]: 1.28; 95% CI: 1.001-1.64; P = .049). Carotid artery stenting procedures (n = 1350) also demonstrated higher S/D rates for lower-volume operators (2.63% for Q1-Q3 [1-11 annual cases] vs 0.37% for Q4-Q5 [12-31 annual cases]; OR: 6.11; 95% CI: 1.27-29.33; P = .024). No significant hospital volume-outcome effect was observed for either procedure. An inverse relationship was demonstrated between operator volume and perioperative S/D rates following CEA and CAS. Consideration of minimum operator thresholds, restructuring of services and networked referral pathways of care in Australia and New Zealand, would likely result in improved patient outcomes.

Nationwide Analysis of Endovascular Thrombectomy Provider Specialization for Acute Stroke

Background and Purpose:

Determine the extent of cerebrovascular expertise among the specialties of proceduralists providing endovascular thrombectomy (ET) for emergent large vessel occlusion stroke in the modern era of acute stroke among Medicare beneficiaries

Methods:

Retrospective cohort study using validated International Classification of Diseases, Tenth Revision , Clinical Modification codes to identify admissions with acute ischemic stroke and treatment with ET. We identified proceduralist specialty by linking the National Provider Identifier provided by Medicare to the specialty listed in the National Provider Identifier database, grouping into radiology, neurology, neurosurgery, other surgical, and internal medicine. We calculated the number of proceduralists and hospitals who performed ET, ET team specialty composition by hospital, and number of proceduralists who performed ET at multiple hospitals.

Results:

Forty-two percent (n=5612) of ET were performed by radiology-background proceduralists, with unclear knowledge of how many were cerebrovascular specialists. Neurosurgery- and neurology-background interventionalists performed fewer but substantial numbers of cases, accounting for 24% (n=3217) and 23% (n=3124) of total cases, respectively. ET teams included a neurology- or neurosurgery-background proceduralist at 65% (n=407) of hospitals that performed ET and included both in 26% (n=160) of teams.

Conclusions:

Almost two-thirds of ET teams nationwide include a neurology- or neurosurgery-background proceduralist and higher volume centers in urban areas were more likely to have neurology- or neurosurgery-background proceduralists with cerebrovascular expertise on their team. It is unclear how many radiology-background interventionalists are cerebrovascular specialists versus generalists. Significant work remains to be done to understand the impact of proceduralist specialty, training, and cerebrovascular expertise on ET outcomes.

Aortic arch types and postoperative outcomes after carotid artery stenting in asymptomatic and symptomatic patients

BACKGROUND

The aim of this study was to investigate the influence of the aortic arch type on technical and clinical success of carotid artery stenting (CAS) procedure.

METHODS

Clinical and anatomical data of consecutive patients who underwent CAS from 2010 to 2018 were prospectively collected and retrospectively analyzed. Primary outcome was technical success, define as successful stent delivery and deployment and <30% residual carotid stenosis. Secondary outcomes were death, stroke, myocardial infarction (MI) and transient ischemic attack (TIA) rates at 30 days after CAS. Subgroups analysis with asymptomatic and symptomatic patients were also performed.

RESULTS

During the study period, 523 patients were enrolled and analyzed. Among these, 176 (33.6%) had Type I, 227 (43.4%) had Type II and 120 (23.0%) had Type III or bovine aortic arch (BAA) type. Technical success rate was achieved in 96.0% of cases. At 30 days, if compared with Type I or II, patient with Type III or BAA experienced a higher death rate (0 vs. 0 vs. 1.8%, respectively; P=0.056) and combined postoperative stroke/TIA rate (3% vs. 2.8% vs. 9.9%, respectively; P=0.012). No differences for same outcomes between asymptomatic and symptomatic patients were described, although the latter group experienced more postoperative MI. A multivariate analysis revealed Type III or BAA as an independent risk factor for postoperative stroke/TIA (HR 3.23, IC95% 1.40-7.45; P=0.006).

CONCLUSIONS

In this cohort of patients, death and postoperative neurological complications rates were associated with Type III or BAA, irrespective of symptomatic patients' status. Extremely attention is required during perioperative period in patients who were candidate to CAS and with challenging aortic arch anatomy.

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.

Trends in hospital procedure volumes for intra-arterial treatment of acute ischemic stroke: results from the paul coverdell national acute stroke program

BACKGROUND

Rates of intra-arterial revascularization treatments (IAT) for acute ischemic stroke (AIS) are increasing in the USA. Using a multi-state stroke registry, we studied the trend in IAT use among patients with AIS over a period spanning 11 years. We examined the impact of IAT rates on hospital procedure volumes and patient outcome after stroke.

METHODS

We used data from the Paul Coverdell National Acute Stroke Program (PCNASP) and explored trends in IAT between 2008 and 2018. Patient outcomes were examined by rates of IAT procedures across hospitals. Specifically, outcomes were compared across low-volume (<15 IAT per year), medium-volume (15-30 IAT per year), and high-volume hospitals (>30 IAT per year). Favorable outcome was defined as discharge to home.

RESULTS

There were 612 958 patients admitted with AIS to 687 participating hospitals within the PCNASP during this study. Only 2.9% of patients (mean age 68.5 years, 49.3% women) received IAT. The percent of patients with AIS receiving IAT increased from 1% in 2008 to 5.3% in 2018 (p<0.001). The proportion of low-volume hospitals decreased over time (p<0.001), and the proportions of medium-volume (p=0.007) and high-volume hospitals (p<0.001) increased between 2008 and 2018. When compared with medium-volume hospitals, high-volume hospitals had a higher (p<0.0001) and low-volume hospitals had a lower (p<0.0001) percent of patients discharged to home.

CONCLUSION

High-volume hospitals were associated with a higher rate of favorable outcome. With the increased use of IAT among patients with AIS, the proportion of low-volume hospitals performing IAT significantly decreased.

Epidemiology and volume-outcome relationship of extracorporeal membrane oxygenation for respiratory failure in Japan: A retrospective observational study using a national administrative database

Aim

To describe the epidemiology of patients on extracorporeal membrane oxygenation (ECMO) and investigate the possible association between outcomes for respiratory ECMO patients and hospital volume of ECMO treatment for any indications.

Methods

Using data from the Diagnosis Procedure Combination database, a nationwide Japanese inpatient database, between 1 July 2010 and 31 March 2018, we identified inpatients aged ≥18 years who underwent ECMO. Institutional case volume was defined as the mean annual number of ECMO cases; eligible patients were categorized into institutional case volume tertile groups. The primary outcome was in-hospital mortality. For ECMO patients with respiratory failure, the association between institutional case volume group and in-hospital mortality rate was analyzed using a multilevel logistic regression model including multiple imputation.

Results

Extracorporeal membrane oxygenation was carried out on 25,384 patients during the study period; of those, 1,227 cases were for respiratory failure. Respiratory cases were categorized into low- (<8 cases/year), medium- (8-16 cases/year), and high-volume groups (≥17 cases/year). The overall in-hospital mortality rate for respiratory ECMO was 62.5% in low-, 54.7% in medium-, and 50.4% in high-volume institutions. With reference to low-volume institutions, the adjusted odds ratios (95% confidence interval) of the medium- and high-volume institutions for in-hospital mortality were 0.72 (0.50-1.04; P = 0.082) and 0.65 (0.45-0.95; P = 0.024), respectively.

Conclusions

The present study showed that accumulating the experience of using ECMO for any indications could positively affect the outcome of ECMO treatment for respiratory failure, which suggests the effectiveness of consolidating ECMO cases in high-volume centers in Japan.

The Potential Impact of "Take the Volume Pledge" on Outcomes After Carotid Artery Stenting

BACKGROUND

The "Volume Pledge" aims to centralize carotid artery stenting (CAS) to hospitals and surgeons performing ≥10 and ≥5 procedures annually, respectively.

OBJECTIVE

To compare outcomes after CAS between hospitals and surgeons meeting or not meeting the Volume Pledge thresholds.

METHODS

We queried the Nationwide Inpatient Sample for CAS admissions. Hospitals and surgeons were categorized as low volume and high volume (HV) based on the Volume Pledge. Multivariable hierarchical regression models were used to examine the impact of hospital volume (2005-2011) and surgeon volume (2005-2009) on perioperative outcomes.

RESULTS

Between 2005 and 2011, 22 215 patients were identified. Most patients underwent CAS by HV hospitals (86.4%). No differences in poor outcome (composite endpoint of in-hospital mortality, postoperative neurological or cardiac complications) were observed by hospital volume but HV hospitals did decrease the likelihood of other complications, nonroutine discharge, and prolonged hospitalization. From 2005 to 2009, 9454 CAS admissions were associated with physician identifiers. Most patients received CAS by HV surgeons (79.2%). On multivariable analysis, hospital volume was not associated with improved outcomes but HV surgeons decreased odds of poor outcome (odds ratio [OR] 0.76, 95% confidence interval [CI] 0.59-0.97; P = .028), complications (OR 0.56, 95% CI 0.46-0.71, P < .001), nonroutine discharge (OR 0.70, 95% CI 0.57-0.87; P = .001), and prolonged hospitalization (OR 0.52, 95% 0.44-0.61, P < .001).

CONCLUSION

Most patients receive CAS by hospitals and providers meeting the Volume Pledge threshold for CAS. Surgeons but not hospitals who met the policy's volume standards were associated with superior outcomes across all measured outcomes.

Snapshot of current carotid artery stenting practice and accreditation in the USA

Objective

The aim of this exploratory study was to compare the performance of carotid artery stenting (CAS) best practices between Intersocietal Accreditation Commission (IAC) accredited facilities and non-accredited facilities certified by the Centers for Medicare and Medicaid Services (CMS).

Methods

A random, anonymous survey was sent to CMS and IAC accredited facilities querying facility routine performance of 16 CAS procedure components found in published guidelines and utilised during clinical trials.

Results

There were 28 responses (response rate=17%). Significant differences were found between the CMS and the IAC facilities for four of 16 procedure measures: determination of modified Rankin Scale score prior to stenting (p=0.012, 95% CI 20% to 80%), accurate measurement of per cent stenosis using electronic callipers (p=0.005, 95% CI 24% to 84%), confirmation of anticoagulation with activated clotting time greater than 250 s prior to crossing the lesion (p=0.03, 95% CI 7% to 69%), and comparison of facility outcomes to accepted benchmarks for stroke and death (p=0.03, 95% CI 7% to 69%). Overall, IAC facilities performed all 16 procedures more frequently (97%) than CMS facilities (66%) (p<0.001, 95% CI 24% to 36%).

Conclusions

Although the sample size was small, the results demonstrated IAC accredited facilities are more likely to follow best practices, to use quantitative tools to select appropriate patients, and quantitively measure patient-centred clinical outcomes compared with CMS certified facilities. The findings raise the question as to the value of CMS certification versus IAC accreditation as a requirement for reimbursement.

Validating Publicly Available Crosswalks for Translating ICD-9 to ICD-10 Diagnosis Codes for Cardiovascular Outcomes Research

Background On October 1, 2015, the Center for Medicare and Medicaid Services transitioned from the International Classification of Diseases, Ninth Revision ( ICD-9) to the ICD, Tenth Revision ( ICD-10) compendium of codes for diagnosis and billing in health care, but translation between the two is often inexact. Here we describe a validated crosswalk to translate ICD-9 codes into ICD-10 codes, with a focus on complications after carotid revascularization and endovascular aortic aneurysm repair. Methods and Results We devised an 8-step process to derive and validate ICD-10 codes from existing ICD-9 codes. We used publicly available sources, including the General Equivalence Mapping database, to translate ICD-9 codes used in prior work to ICD-10 codes. We defined ICD-10 codes as validated if they were concordant with the initial ICD-9 codes after manual comparison by two physicians. Our primary validation measure was the percent of valid ICD-10 codes out of the total ICD-10 codes obtained during translation. We began with 126 ICD-9 diagnosis codes used for complication identification after carotid revascularization procedures, and 97 ICD-9 codes for complications after endovascular aortic aneurysm procedures. Translation generated 143 ICD-10 codes for carotid revascularization, a 14% increase from the initial 126 codes. Manual comparison demonstrated 98% concordance, with 99% agreement between the reviewers. Similarly, we identified 108 ICD-10 codes for endovascular aortic aneurysm repair, an 11% increase from the initial 97 ICD-9 codes. We again noted excellent concordance and agreement (98% and 100%, respectively). Manual review identified 4 ICD-10 codes incorrectly translated from ICD-9 codes for carotid revascularization, and 3 codes incorrectly translated for endovascular aortic aneurysm repair. Conclusions Algorithms to crosswalk lists of ICD-9 codes to ICD-10 codes can leverage electronic resources to minimize the burden of code translation. However, manual review for code validation may be necessary, with collaboration across institutions for researchers to share their efforts.

Effect of the Number of Neurointerventionalists on Off-Hour Endovascular Therapy for Acute Ischemic Stroke Within 12 Hours of Symptom Onset

Background

Off‐hour presentation can affect treatment delay and clinical outcomes in endovascular therapy (EVT) for acute ischemic stroke. We aimed to examine the treatment delays and clinical outcomes of EVT between on‐ and off‐hour admission and to evaluate the effect of hospital procedure volume and the number of neurointerventionalists on off‐hour EVT.

Methods and Results

From a multicenter registry, we identified patients who were treated with EVT within 12 hours of symptom. Annual hospital procedure volume was divided as low (<30), medium (30–60), and high (>60). The effect of the number of neurointerventionalists and annual hospital procedure volume on clinical outcome was estimated by the generalized estimation equation. Of the 31 133 stroke patients, 1564 patients met the eligibility criteria (mean age: 69±12 years; median baseline National Institutes of Health stroke scale score, 15 [interquartile range, 10–19]). Of 1564 patients, 893 (57.1%) arrived during off‐hour. The off‐hour patients had greater median door‐to‐puncture time (110  versus 95 minutes; P<0.001) compared with on‐hour patients. Despite the treatment delay, the functional outcome at 3 months did not differ between off‐ and on‐hour (odds ratio with 95% CI for 3‐month modified Rankin Scale 0–2, 0.99 [0.78–1.25]; P=0.90). The presence of three neurointerventionalists was significantly associated with favorable outcomes at 3 months during on‐ and off‐hour (2.07 [1.53–2.81]; P<0.001). The association was not observed for annual hospital procedural volume and the functional outcomes.

Conclusions

The number of neurointerventionalists was more crucial to effective around‐the‐clock EVT for acute stroke patients than hospital procedural volume.

Long-term Outcomes of Carotid Endarterectomy Versus Stenting in a Multicenter Population-based Canadian Study

OBJECTIVE

To compare the long-term outcomes of patients treated with carotid endarterectomy and carotid-artery stenting.

BACKGROUND

Evidence for the long-term safety and efficacy of carotid-artery stenting compared with endarterectomy is accumulating from randomized trials. However, comparative data on the long-term outcomes of carotid revascularization strategies in real world practice are lacking.

METHODS

We conducted a population-based, multicenter, observational cohort study using validated linked databases from Ontario, Canada. We identified all individuals treated with carotid endarterectomy and stenting (2002-2014), and followed them up to 2015. We compared long-term (up to 13 years) and 30-day outcomes of each strategy using multilevel multivariable Cox proportional-hazards models, and conducted confirmatory analyses using propensity-score matching methods.

RESULTS

In all, 15,525 patients received carotid-artery revascularization. Rate of the primary composite outcome of 30-day death, stroke, or myocardial infarction plus any stroke during 13-year follow-up was higher with stenting (16.3%) compared with endarterectomy (9.7%) [adjusted hazard ratio (HR) 1.57, 95% confidence interval (CI) 1.43-1.73, P < 0.001). The increased risk with stenting was observed regardless of age, sex, intervention year, carotid-artery symptoms, or diabetes. The primary outcome was driven by higher rates of 30-day stroke (adjusted HR 1.59, 95% CI 1.29-1.95), 30-day death (adjusted HR 2.62, 95% CI 2.20-3.13), and long-term stroke >30 days after the procedure (adjusted HR 1.47, 95% CI 1.36-1.59) with stenting; 30-day myocardial infarction was lower with stenting (adjusted HR 0.70, 95% CI 0.57-0.86). These results were confirmed with 1:2 propensity-score matching (HR for primary composite outcome with stenting 1.55, 95% CI 1.31-1.83, P < 0.001).

CONCLUSIONS

Compared with carotid endarterectomy, stenting was associated with an early and sustained approximately 55% increased hazard for major adverse events over long-term follow-up. Although nonrandomized, these results raise potential concerns about the interchangeability of carotid endarterectomy and stenting in the context of actual clinical practice.

Carotid Revascularization with and without the Use of an Embolic Protection Device: A Single-Center Experience from Pakistan

Background

To assess the safety and clinical efficacy of carotid artery stenting with and without an embolic protection device (EPD) in both symptomatic and asymptomatic carotid disease cases.

Methods

Retrospective data of 55 symptomatic (≥50% occlusion by digital subtraction angiography [DSA], ≥70% by ultrasound, computed tomography angiography [CTA], and magnetic resonance angiography [MRA]) and asymptomatic (≥60% by DSA, ≥70% by ultrasound, ≥80% by CTA and MRA) carotid disease cases undergoing carotid stenting/angioplasty revascularization from February 2014 to October 2017 was reviewed. All symptomatic patients either experienced recurrent transient ischemic attacks or one or more stroke attacks. An EPD protocol was designed for its selective use based on plaque morphologies and working diameters. The primary end points at 30 days of follow-up were a periprocedural incidence of any stroke, myocardial infarction or death, and ipsilateral stroke during the follow-up period.

Results

Of the 55 cases, 39 were males and 16 females; mean age was 64.8 years. Fifty-one patients (92.7%) were symptomatic, with a mean stenosis of 80.1%. EPD was used in only 11 cases (20%). Minor stroke rate during the first 30 postoperative days was 1.8% (1 case) with EPD; no myocardial infarction or mortality. No stroke occurred during the median 1.5 years' follow-up.

Conclusion

Based on our single-center experience and findings of a relatively small sample size, carotid revascularization with stenting and angioplasty without EPD in experienced hands was found to be safe and efficacious. In addition, it proves cost-effective for patients by limiting the use of unnecessary disposables. These results are comparable to those reported in major trials and are well within the complication thresholds suggested in current guidelines. These results also show promise and illustrate the need for a larger, randomized controlled trial in order to thoroughly address this aspect of carotid revascularization.

Risk-Benefit Assessment of Carotid Revascularization

Severe carotid atherosclerotic disease is responsible for 14% of all strokes, which result in a high rate of morbidity and mortality. In recent years, advances in clinical treatment of cardiovascular diseases have resulted in a significant decrease in mortality due to these causes. To review the main studies on carotid revascularization, evaluating the relationship between risks and benefits of this procedure. The data reviewed show that, for a net benefit, carotid intervention should only be performed in cases of a periprocedural risk of less than 6% in symptomatic patients. The medical therapy significantly reduced the revascularization net benefit ratio for stroke prevention in asymptomatic patients. Real life registries indicate that carotid stenting is associated with a greater periprocedural risk. The operator annual procedure volume and patient age has an important influence in the rate of stroke and death after carotid stenting. Symptomatic patients have a higher incidence of death and stroke after the procedure. Revascularization has the greatest benefit in the first weeks of the event. There is a discrepancy in the scientific literature about carotid revascularization and/or clinical treatment, both in primary and secondary prevention of patients with carotid artery injury. The identification of patients who will really benefit is a dynamic process subject to constant review.

Relationship between patient safety indicator events and comprehensive stroke center volume status in the treatment of unruptured cerebral aneurysms

OBJECTIVE

The Agency of Healthcare Research and Quality (AHRQ) has defined Patient Safety Indicators (PSIs) for assessments in quality of inpatient care. The hypothesis of this study is that, in the treatment of unruptured cerebral aneurysms (UCAs), PSI events are less likely to occur in hospitals meeting the volume thresholds defined by The Joint Commission for Comprehensive Stroke Center (CSC) certification.

METHODS

Using the 2002–2011 National (Nationwide) Inpatient Sample, patients treated electively for a nonruptured cerebral aneurysm were selected. Patients were evaluated for PSI events (e.g., pressure ulcers, retained surgical item, perioperative hemorrhage, pulmonary embolism, sepsis) defined by AHRQ-specified ICD-9 codes. Hospitals were categorized by treatment volume into CSC or non-CSC volume status based on The Joint Commission’s annual volume thresholds of at least 20 patients with subarachnoid hemorrhage and performance of 15 or more endovascular coiling or surgical clipping procedures for aneurysms.

RESULTS

A total of 65,824 patients underwent treatment for an unruptured cerebral aneurysm. There were 4818 patients (7.3%) in whom at least 1 PSI event occurred. The overall inpatient mortality rate was 0.7%. In patients with a PSI event, this rate increased to 7% compared with 0.2% in patients without a PSI event (p < 0.0001). The overall rate of poor outcome was 3.8%. In patients with a PSI event, this rate increased to 23.3% compared with 2.3% in patients without a PSI event (p < 0.0001). There were significant differences in PSI event, poor outcome, and mortality rates between non-CSC and CSC volume-status hospitals (PSI event, 8.4% vs 7.2%; poor outcome, 5.1% vs 3.6%; and mortality, 1% vs 0.6%). In multivariate analysis, all patients treated at a non-CSC volume-status hospital were more likely to suffer a PSI event with an OR of 1.2 (1.1–1.3). In patients who underwent surgery, this relationship was more substantial, with an OR of 1.4 (1.2–1.6). The relationship was not significant in the endovascularly treated patients.

CONCLUSIONS

In the treatment of unruptured cerebral aneurysms, PSI events occur relatively frequently and are associated with significant increases in morbidity and mortality. In patients treated at institutions achieving the volume thresholds for CSC certification, the likelihood of having a PSI event, and therefore the likelihood of poor outcome and mortality, was significantly decreased. These improvements are being driven by the improved outcomes in surgical patients, whereas outcomes and mortality in patients treated endovascularly were not sensitive to the CSC volume status of the hospital and showed no significant relationship with treatment volumes.

Strategies for New Skill Acquisition by Practicing Surgeons

OBJECTIVE

To understand how practicing surgeons utilize available training methods, which methods are perceived as effective, and important barriers to using more effective methods.

DESIGN

Online survey designed to characterize surgeon utilization and perception of available training methods.

SETTING

Two large Midwestern academic health centers.

PARTICIPANTS

150 faculty surgeons.

METHODS

Nominal values were compared using a McNemar's Test and Likert-like values were compared using a paired t-test (IBM SPSS Statistics v. 21.0; New York, NY).

RESULTS

Survey response rate was 81% (122/150). 98% of surgeons reported learning a new procedure or technology after formal training. Many surgeons reported scrubbing in expert cases (78%) and self-directed study (66%), while few surgeons (6%) completed a mini-fellowship. The modalities used most commonly were scrubbing in expert cases (34%) and self-directed study (27%). Few surgeons (7%) believed self-directed study would be most effective, whereas 31% and 16% believed operating under supervision and mini-fellowships would be most effective, respectively. Surgeons believed more effective methods "would require too much time" or they had "confidence in their ability to implement safely."

CONCLUSIONS

Practicing surgeons use a variety of training methods when learning new procedures and technologies, and there is disconnect between commonly used training methods and those deemed most effective. Confidence in surgeon's ability was cited as a reason for this discrepancy; and surgeons found time associated with more effective methods to be prohibitive.

Carotid Artery Stent Placement and Carotid Endarterectomy: A Challenge for Urgent Treatment after Stroke-Early and 12-Month Outcomes in a Comprehensive Stroke Center

PURPOSE

To compare feasibility, 12-month outcome, and periprocedural and postprocedural risks between carotid artery stent (CAS) placement and carotid endarterectomy (CEA) performed within 1 week after transient ischemic attack (TIA) or mild to severe stroke onset in a single comprehensive stroke center.

MATERIALS AND METHODS

Retrospective analysis of prospective data collected from 1,148 patients with ischemic stroke admitted to a single stroke unit between January 2013 and July 2015 was conducted. Among 130 consecutive patients with symptomatic carotid stenosis, 110 (10 with TIA, 100 with stroke) with a National Institutes of Health Stroke Scale (NIHSS) score < 20 and a prestroke modified Rankin Scale (mRS) score < 2 were eligible for CAS placement or CEA and treated according to the preference of the patient or a surrogate. Periprocedural (< 48 h) and postprocedural complications, functional outcome, stroke, and death rate up to 12 months were analyzed.

RESULTS

Sixty-two patients were treated with CAS placement and 48 were treated with CEA. Several patients presented with moderate or major stroke (45.8% CEA, 64.5% CAS). NIHSS scores indicated slightly greater severity at onset in patients treated with a CAS vs CEA (6.6 ± 5.7 vs 4.2 ± 3.4; P = .08). Complication rates were similar between groups. mRS scores showed a significant improvement over time and a significant interaction with age in both groups. Similar incidences of death or stroke were shown on survival analysis. A subanalysis in patients with NIHSS scores ≥ 4 showed no differences in complication rate and outcome.

CONCLUSIONS

CAS placement and CEA seem to offer early safe and feasible secondary stroke prevention treatments in experienced centers, even after major atherosclerotic stroke.

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.

Paramedic Out-of-hospital Cardiac Arrest Case Volume Is a Predictor of Return of Spontaneous Circulation

Introduction

Many factors contribute to the survival of out-of-hospital cardiac arrest (OHCA). One such factor is the quality of resuscitation efforts, which in turn may be a function of OHCA case volume. However, few studies have investigated the OHCA case volume-survival relationship. Consequently, we sought to develop a model describing the likelihood of return of spontaneous circulation (ROSC) as a function of paramedic cumulative OHCA experience.

Methods

We conducted a statewide retrospective study of cardiac arrest using the North Carolina Prehospital Care Reporting System. Adult patients suffering a witnessed, non-traumatic cardiac arrest between January 2012 and June 2014 were included. Using logistic regression, we calculated an adjusted odds ratio (OR) for the influence of the preceding five-year paramedic OHCA case volume on ROSC while controlling for the potentially confounding variables identified a priori as patient age, gender, and non-Caucasian race; shockable presenting rhythm; layperson/first responder cardiopulmonary resuscitation (CPR); and emergency medical services (EMS) response time.

Results

Of the 6,405 patients meeting inclusion criteria, 3,155 (49.3%) experienced ROSC. ROSC was more likely among patients treated by paramedics with ≥ 15 OHCA experiences during the preceding five years (OR [1.21], p<0.01). ROSC was also more likely among patients with shockable initial rhythms (OR [2.35], p<0.01) and who received layperson/first responder CPR (OR [1.77], p<0.01). Increasing patient age (OR [0.996], p=0.02), male gender (OR [0.742], p<0.01), and increasing EMS response time (OR [0.954], p<0.01) were associated with a decreased likelihood of ROSC. Non-Caucasian race was not an independent predictor of ROSC.

Conclusion

We found that a paramedic five-year OHCA case volume of ≥ 15 is significantly associated with ROSC. Further study is needed to determine the specific actions of these more experienced paramedics who are responsible for the increased likelihood of ROSC, as well as the influence of case volume on the longer-term outcome measures of hospital discharge and neurological function.

Predictors of Perioperative Stroke/Death after Carotid Artery Stenting: A Review Article

Carotid artery stenting (CAS) has been recommended as an alternative treatment to carotid endarterectomy for patients with significant carotid stenosis. Only a few studies have analyzed clinical/anatomical and technical variables that affect perioperative outcomes of CAS. Following a comprehensive Medline search, it was reported that clinical factors, including age of >80 years, chronic renal failure, diabetes mellitus, symptomatic indications, and procedures performed within 2 weeks of transient ischemic attack symptoms, are associated with high perioperative stroke and death rates. They also highlighted that angiographic variables, e.g., ulcerated and calcified plaques, left carotid intervention, >90% stenosis, >10-mm target lesion length, ostial involvement, type III aortic arch, and >60°-angulated internal carotid and common carotid arteries, are predictors of increased stroke rates. Technical factors associated with increased perioperative risk of stroke include percutaneous transluminal angioplasty (PTA) without embolic protection devices, PTA before stent placement, and the use of multiple stents. This review describes the most widely quoted data in defining various predictors of perioperative stroke and death after CAS. (This is a review article based on the invited lecture of the 45th Annual Meeting of Japanese Society for Vascular Surgery.)