Predicting risk of perioperative death and stroke after carotid endarterectomy in asymptomatic patients: derivation and validation of a clinical risk score

The role of inflammation biomarkers in carotid artery stenosis procedures

BACKGROUND

Carotid revascularization procedures, such as carotid endarterectomy (CEA) and carotid artery stenting (CAS), can lead to restenosis. Monitoring restenosis onset through biomarkers is crucial in clinical practice. This study aimed to evaluate inflammation biomarkers in CEA and CAS to determine their predictive value for restenosis risk post-procedure.

METHODS

A retrospective analysis was conducted on the clinical records of patients with carotid stenosis who underwent CEA or CAS over one year at the Vascular Surgery departments of an interuniversity center. Eligible asymptomatic patients with carotid stenosis (70-99%) underwent revascularization. Differences between pre- and early post-procedural inflammation indices were assessed, and restenosis risk was evaluated using Receiver Operating Curve analysis and logistic regression.

RESULTS

The cohort comprised 100 patients, 68 undergoing CEA and 32 undergoing CAS. Significant values were observed for inflammation ratios post-CEA: neutrophils to lymphocytes ratio (NLR) (p=0.036), platelets to lymphocytes ratio (PLR) (p=0.009), monocytes to lymphocytes ratio (MLR) (p<0.001), systemic inflammation index (SII) (p=0.024), systemic immune response index (SIRI) (p=0.003), and aggregate inflammation response index (AISI) (p<0.001). At 12-month follow-up, 12% of patients experienced restenosis; 50% were men and 50% women. Women showed a higher restenosis rate (26.1% vs 7.8%). Pre-intervention NLR (OR [95% CI] = 13.38 [1.88 to 95.44], p=0.010) and SIRI (OR [95% CI] = 10.22 [2.65 to 39.43], p=0.001) remained significantly associated with restenosis after adjusting for sex and smoking.

CONCLUSION

The study provided a predictive model for restenosis, identifying pre-intervention NLR and SIRI as independent predictors of restenosis at 12-month follow-up.

30-Day Risk Score for Mortality and Stroke in Patients with Carotid Artery Stenosis Using Artificial Intelligence Based Carotid Plaque Morphology

OBJECTIVES

The gold standard for determining carotid artery stenosis intervention is based on a combination of percent stenosis and symptomatic status. Few studies have assessed plaque morphology as an additive tool for stroke prediction. Our goal was to create a predictive model and risk score for 30-day stroke and death inclusive of plaque morphology.

METHODS

Patients with a CT angiography head/neck between 2010-2021 at a single institution and a diagnosis of carotid artery stenosis were included in our analysis. Each CT was used to create a 3D image of carotid plaque based off image recognition software. A stepwise backward regression was used to select variables for inclusion in our prediction models. Model discrimination was assessed with receiver operating characteristic curves (AUC). Additionally, calibration was performed and the model with the least Akaike Information Criterion (AIC) was selected. The risk score was modeled from the Framingham Study. Primary outcome was mortality/stroke.

RESULTS

We created three models to predict mortality/stroke from 366 patients: model A using only clinical variables, model B using only plaque morphology and model C using both clinical and plaque morphology variables. Model A used age, sex, PAD, hyperlipidemia, BMI, COPD, and history of TIA/stroke and had an AUC of 0.737 and AIC of 285.4. Model B used perivascular adipose tissue volume, lumen area, calcified volume, and target lesion length and had an AUC of 0.644 and AIC of 304.8. Finally, model C combined both clinical and software variables of age, sex, matrix volume, history of TIA/stroke, BMI, perivascular adipose tissue, lipid rich necrotic core, COPD and hyperlipidemia and had an AUC of 0.759 and an AIC of 277.6. Model C was the most predictive because it had the highest AUC and lowest AIC.

CONCLUSION

Our study demonstrates that combining both clinical factors and plaque morphology creates the best predication of a patient's risk for all-cause mortality or stroke from carotid artery stenosis. Additionally, we found that for patients with even 3 points in our risk score model have a 20% chance of stroke/death. Further prospective studies are needed to validate our findings.

Neuroprotective association of preoperative renin-angiotensin system blocking agents use in patients undergoing carotid interventions

OBJECTIVE

The optimal medical management strategy in the periprocedural period for patients undergoing carotid artery interventions is not well described. Renin-angiotensin-system blocking (RASB) agents are considered to be among the first line anti-hypertensive agents; however, their role in the perioperative period is unclear. The objective of this study was to examine the relationship between the use of RASB agents on periprocedural outcomes in patients undergoing carotid interventions-carotid endarterectomy (CEA), transfemoral carotid artery stenting (CAS), and transcervical carotid artery revascularization (TCAR).

METHOD

The Society for Vascular Surgery Quality Initiative database was queried for all patients undergoing CAS, CEA, and TCAR between 2003 and 2020. Patients were stratified into two groups based upon their use of RASB agents in the periprocedural period. The primary endpoint was periprocedural neurologic events (including both strokes and transient ischemic attacks (TIAs)). The secondary endpoints were peri-procedural mortality and significant cardiac events, including myocardial infarction, dysrhythmia, and congestive heart failure.

RESULTS

Over 150,000 patients were included in the analysis: 13,666 patients underwent TCAR, 13,811 underwent CAS, and 125,429 underwent CEA for carotid artery stenosis. Overall, 52.2% of patients were maintained on RASB agents. Among patients undergoing CEA, patients on RASB agents had a significantly lower rate of periprocedural neurologic events (1.7% versus 2.0%, p =0.001). The peri-procedural neurological event rate in the TCAR cohort was similarly reduced in those treated with RASB agents, but did not reach statistical significance (2.0% vs 2.4%, p = 0.162). Among patients undergoing CAS, there was no difference in perioperative neurologic events between the RASB treated and untreated cohorts (3.4% vs 3.2%, p = 0.234); however, the use of RASB agents was significantly associated with lower mortality (1.2% vs 1.7%, p =0.001) with CAS. The use of preoperative RAS-blocking agents did not appear to affect the overall rates of adverse cardiac events with any of the three carotid intervention types, or periprocedural mortality following CEA or TCAR. On multivariable analysis, the use of RAS-blocking agents was independently associated with lower rates of post-procedural neurologic events in patients undergoing CEA (OR 0.819, CI 0.747-0.898; p = 0.01) and TCAR (OR 0.869, CI 0.768-0.984; p = 0.026), but not in those undergoing CAS (OR 0.967, CI 0.884-1.057; p = 0.461).

CONCLUSION

The use of peri-procedural RASB agents was associated with a significantly decreased rate of neurologic events in patients undergoing both CEA and TCAR. This effect was not observed in patients undergoing CAS. As carotid interventions warrant absolute minimization of perioperative complications in order to provide maximum efficacy with regard to stroke protection, the potential neuro-protective effect associated with RASB agents use following CEA and TCAR warrants further examination.

Carotid calcium burden derived from computed tomography angiography as a predictor of all-cause mortality after carotid endarterectomy

OBJECTIVE

Carotid endarterectomy (CEA) aims to reduce the risk of stroke in patients with atherosclerotic carotid disease. Preoperative risk assessments that predict complications are needed to optimize the care in this patient group. The current approach, namely relying solely on symptomatology and degree of stenosis, is outdated and calls for innovation. The Agatston calcium score was applied in several vascular specialties to assess cardiovascular risk profile but has been little studied in carotid surgery. It is hypothesized that a higher calcium burden at initial presentation equates to a worse prognosis attributable to an increased cerebrovascular and cardiovascular risk profile. The aim was to investigate the association between preoperative ipsilateral calcium score and postoperative all-cause mortality in patients undergoing CEA.

METHODS

This single-center retrospective cohort study included 89 patients who underwent CEA at a tertiary referral center between 2010 and 2018. Preoperative calcium scores were measured on contrast-enhanced computed tomography images with patient-specific Hounsfield thresholds at the level of the carotid bifurcation. The association between these calcium scores and all-cause mortality was analyzed using multivariable adjusted Cox proportional hazard analysis.

RESULTS

Cox proportional hazard analysis demonstrated a significant association between preoperative ipsilateral carotid calcium score and all-cause mortality (hazard ratio, 1.10; 95% confidence interval, 1.03-1.16; P = .003). After adjusting for age, preoperative estimated glomerular filtration rate, and diabetes mellitus, a significant association remained (hazard ratio, 1.07; 95% confidence interval, 1.00-1.15; P = .05).

CONCLUSIONS

A higher calcium burden was predictive of worse outcome, which might be explained by an overall poorer health status. These results highlight the potential of calcium measurements in combination with other traditional risk factors, for preoperative risk assessment and thus for improved patient education and care.

Sex differences in outcome after carotid revascularization in symptomatic and asymptomatic carotid artery stenosis

OBJECTIVE

Sex differences regarding the safety and efficacy of carotid revascularization in carotid artery stenosis have been addressed in several studies with conflicting results. Moreover, women are underrepresented in clinical trials, leading to limited conclusions regarding the safety and efficacy of acute stroke treatments.

METHODS

A systematic review and meta-analysis was performed by literature search including four databases from January 1985 to December 2021. Sex differences in the efficacy and safety of revascularization procedures, including carotid endarterectomy (CEA) and carotid artery stenting (CAS), for symptomatic and asymptomatic carotid artery stenoses were analyzed.

RESULTS

Regarding CEA in symptomatic carotid artery stenosis, the stroke risk in men (3.6%) and women (3.9%) based on 99,495 patients (30 studies) did not differ (P = .16). There was also no difference in the stroke risk by different time frames up to 10 years. Compared with men, women treated with CEA had a significantly higher stroke or death rate at 4 months (2 studies, 2565 patients; 7.2% vs 5.0%; odds ratio [OR], 1.49; 95% confidence interval [CI], 1.04-2.12; I2 = 0%; P = .03), and a significantly higher rate of restenosis (1 study, 615; 17.2% vs 6.7%; OR, 2.81; 95% CI, 1.66-4.75; P = .0001). For CAS in symptomatic artery stenosis, data showed a non-significant tendency toward higher peri-procedural stroke in women, whereas for asymptomatic carotid artery stenosis, data based on 332,344 patients showed that women (compared with men) after CEA had similar rates of stroke, stroke or death, and the composite outcome stroke/death/myocardial infarction. The rate of restenosis at 1 year was significantly higher in women compared with men (1 study, 372 patients; 10.8% vs 3.2%; OR, 3.71; 95% CI, 1.49-9.2; P = .005). Furthermore, CAS in asymptomatic patients was associated with low risk of a postprocedural stroke in both sexes, but a significantly higher risk of in-hospital myocardial infarction in women than men (8445 patients, 1.2% vs 0.6%; OR, 2.01; 95% CI, 1.23-3.28; I2 = 0%; P = .005).

CONCLUSIONS

A few sex-differences in short-term outcomes after carotid revascularization for symptomatic and asymptomatic carotid artery stenosis were found, although there were no significant differences in the overall stroke. This indicates a need for larger multicenter prospective studies to evaluate these sex-specific differences. More women, including those aged over 80 years, need to be enrolled in randomized controlled trials, to better understand if sex differences exist and to tailor carotid revascularization accordingly.

Role of risk scoring systems in predicting life expectancy after carotid endarterectomy in asymptomatic patients

OBJECTIVE

The aim of this study is to compare and to test the performance of all available risk scoring systems (RSSs) designed to predict long-term survival rate in asymptomatic candidate patients for carotid endarterectomy (CEA) for significant carotid artery stenosis.

METHODS

Data on asymptomatic patients who underwent CEA in three high-volume centers were prospectively recorded. Through literature research using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, six RSSs were identified for the intent of the study. Primary endpoints were 3- and 5-year survival rates after CEA. All items used as variables to compose multiple RSSs were applied to every patient in the study population. The 3- and 5-year mortality prediction rates for each score were assessed by sensitivity, specificity, and predictive negative and positive value calculation, as well as univariable Cox proportional hazard models with the Harrell C index.

RESULTS

During the study period, 825 CEAs in 825 asymptomatic patients were analyzed. All items used in RSSs were available in the dataset, with some concerns regarding their definition and application among RSSs. The 3- and 5-year survival rates of the study cohort were 94.5% and 90.3%, respectively. Among the six RSSs analyzed, no RSS demonstrated optimal results in terms of mortality rate prediction accuracy, although some scores had good diagnostic and risk of death precision.

CONCLUSIONS

RSSs, when used alone, fail to optimally detect postoperative life expectancy in asymptomatic CEA patient candidates. Further prospective controlled studies are needed to compose and validate RSSs with better calibration to predict outcomes.

External Validation of Risk Prediction Models to Improve Selection of Patients for Carotid Endarterectomy

BACKGROUND AND PURPOSE

The net benefit of carotid endarterectomy (CEA) is determined partly by the risk of procedural stroke or death. Current guidelines recommend CEA if 30-day risks are <6% for symptomatic stenosis and <3% for asymptomatic stenosis. We aimed to identify prediction models for procedural stroke or death after CEA and to externally validate these models in a large registry of patients from the United States.

METHODS

We conducted a systematic search in MEDLINE and EMBASE for prediction models of procedural outcomes after CEA. We validated these models with data from patients who underwent CEA in the American College of Surgeons National Surgical Quality Improvement Program (2011-2017). We assessed discrimination using C statistics and calibration graphically. We determined the number of patients with predicted risks that exceeded recommended thresholds of procedural risks to perform CEA.

RESULTS

After screening 788 reports, 15 studies describing 17 prediction models were included. Nine were developed in populations including both asymptomatic and symptomatic patients, 2 in symptomatic and 5 in asymptomatic populations. In the external validation cohort of 26 293 patients who underwent CEA, 702 (2.7%) developed a stroke or died within 30-days. C statistics varied between 0.52 and 0.64 using all patients, between 0.51 and 0.59 using symptomatic patients, and between 0.49 to 0.58 using asymptomatic patients. The Ontario Carotid Endarterectomy Registry model that included symptomatic status, diabetes, heart failure, and contralateral occlusion as predictors, had C statistic of 0.64 and the best concordance between predicted and observed risks. This model identified 4.5% of symptomatic and 2.1% of asymptomatic patients with procedural risks that exceeded recommended thresholds.

CONCLUSIONS

Of the 17 externally validated prediction models, the Ontario Carotid Endarterectomy Registry risk model had most reliable predictions of procedural stroke or death after CEA and can inform patients about procedural hazards and help focus CEA toward patients who would benefit most from it.

The comparative and added prognostic value of biomarkers to the Revised Cardiac Risk Index for preoperative prediction of major adverse cardiac events and all-cause mortality in patients who undergo noncardiac surgery

BACKGROUND

The Revised Cardiac Risk Index (RCRI) is a widely acknowledged prognostic model to estimate preoperatively the probability of developing in-hospital major adverse cardiac events (MACE) in patients undergoing noncardiac surgery. However, the RCRI does not always make accurate predictions, so various studies have investigated whether biomarkers added to or compared with the RCRI could improve this.

OBJECTIVES

Primary: To investigate the added predictive value of biomarkers to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Secondary: To investigate the prognostic value of biomarkers compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Tertiary: To investigate the prognostic value of other prediction models compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery.

SEARCH METHODS

We searched MEDLINE and Embase from 1 January 1999 (the year that the RCRI was published) until 25 June 2020. We also searched ISI Web of Science and SCOPUS for articles referring to the original RCRI development study in that period.

SELECTION CRITERIA

We included studies among adults who underwent noncardiac surgery, reporting on (external) validation of the RCRI and: - the addition of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of the RCRI to other models. Besides MACE, all other adverse outcomes were considered for inclusion.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form based on the CHARMS checklist. Independent pairs of authors screened references, extracted data and assessed risk of bias and concerns regarding applicability according to PROBAST. For biomarkers and prediction models that were added or compared to the RCRI in ≥ 3 different articles, we described study characteristics and findings in further detail. We did not apply GRADE as no guidance is available for prognostic model reviews.

MAIN RESULTS

We screened 3960 records and included 107 articles.   Over all objectives we rated risk of bias as high in ≥ 1 domain in 90% of included studies, particularly in the analysis domain. Statistical pooling or meta-analysis of reported results was impossible due to heterogeneity in various aspects: outcomes used, scale by which the biomarker was added/compared to the RCRI, prediction horizons and studied populations.  Added predictive value of biomarkers to the RCRI Fifty-one studies reported on the added value of biomarkers to the RCRI. Sixty-nine different predictors were identified derived from blood (29%), imaging (33%) or other sources (38%). Addition of NT-proBNP, troponin or their combination improved the RCRI for predicting MACE (median delta c-statistics: 0.08, 0.14 and 0.12 for NT-proBNP, troponin and their combination, respectively). The median total net reclassification index (NRI) was 0.16 and 0.74 after addition of troponin and NT-proBNP to the RCRI, respectively. Calibration was not reported. To predict myocardial infarction, the median delta c-statistic when NT-proBNP was added to the RCRI was 0.09, and 0.06 for prediction of all-cause mortality and MACE combined. For BNP and copeptin, data were not sufficient to provide results on their added predictive performance, for any of the outcomes. Comparison of the predictive value of biomarkers to the RCRI  Fifty-one studies assessed the predictive performance of biomarkers alone compared to the RCRI. We identified 60 unique predictors derived from blood (38%), imaging (30%) or other sources, such as the American Society of Anesthesiologists (ASA) classification (32%). Predictions were similar between the ASA classification and the RCRI for all studied outcomes. In studies different from those identified in objective 1, the median delta c-statistic was 0.15 and 0.12 in favour of  BNP and NT-proBNP alone, respectively, when compared to the RCRI, for the prediction of MACE. For C-reactive protein, the predictive performance was similar to the RCRI. For other biomarkers and outcomes, data were insufficient to provide summary results. One study reported on calibration and none on reclassification. Comparison of the predictive value of other prognostic models to the RCRI   Fifty-two articles compared the predictive ability of the RCRI to other prognostic models. Of these, 42% developed a new prediction model, 22% updated the RCRI, or another prediction model, and 37% validated an existing prediction model. None of the other prediction models showed better performance in predicting MACE than the RCRI. To predict myocardial infarction and cardiac arrest, ACS-NSQIP-MICA had a higher median delta c-statistic of 0.11 compared to the RCRI. To predict all-cause mortality, the median delta c-statistic was 0.15 higher in favour of ACS-NSQIP-SRS compared to the RCRI. Predictive performance was not better for CHADS₂, CHA₂DS₂-VASc, R₂CHADS₂, Goldman index, Detsky index or VSG-CRI compared to the RCRI for any of the outcomes. Calibration and reclassification were reported in only one and three studies, respectively.

AUTHORS' CONCLUSIONS

Studies included in this review suggest that the predictive performance of the RCRI in predicting MACE is improved when NT-proBNP, troponin or their combination are added. Other studies indicate that BNP and NT-proBNP, when used in isolation, may even have a higher discriminative performance than the RCRI. There was insufficient evidence of a difference between the predictive accuracy of the RCRI and other prediction models in predicting MACE. However, ACS-NSQIP-MICA and ACS-NSQIP-SRS outperformed the RCRI in predicting myocardial infarction and cardiac arrest combined, and all-cause mortality, respectively. Nevertheless, the results cannot be interpreted as conclusive due to high risks of bias in a majority of papers, and pooling was impossible due to heterogeneity in outcomes, prediction horizons, biomarkers and studied populations. Future research on the added prognostic value of biomarkers to existing prediction models should focus on biomarkers with good predictive accuracy in other settings (e.g. diagnosis of myocardial infarction) and identification of biomarkers from omics data. They should be compared to novel biomarkers with so far insufficient evidence compared to established ones, including NT-proBNP or troponins. Adherence to recent guidance for prediction model studies (e.g. TRIPOD; PROBAST) and use of standardised outcome definitions in primary studies is highly recommended to facilitate systematic review and meta-analyses in the future.

Combined risk modelling approach to identify the optimal carotid revascularisation approach

BACKGROUND

Carotid endarterectomy (CEA) results in fewer perioperative strokes, but more myocardial infarctions (MI) than carotid artery stenting (CAS). We explored a combined modelling approach that stratifies patients by baseline stroke and MI.

METHODS

Baseline registry-based risk models for perioperative stroke and MI were identified via literature search. We then selected treatment risk models in the Carotid Revascularisation Stenting versus Endarterectomy (CREST) trial by serially adding covariates (baseline risk, treatment (CEA vs CAS), treatment-risk interaction and age-treatment interaction terms). Treatment risk models were externally validated using data from the Society for Vascular Surgery (SVS) Vascular Quality Initiative (VQI) CEA and carotid stenting registries and treatment models were recalibrated to the SVS-VQI population. Predicted net benefit was estimated by summing the predicted stroke and MI risk differences with CEA versus CAS.

RESULTS

Perioperative treatment models had moderate predictiveness (c-statistic 0.69 for stroke and 0.68 for MI) and reasonable calibration across the risk spectrum for both stroke and MI within CREST. On external validation in SVS-VQI, predictiveness was substantially reduced (c-statistic 0.61 for stroke and 0.54 for MI) and models substantially overpredicted risk.Most patients (86.7%) were predicted to have net benefit from CEA in CREST (97.0% of symptomatic patients vs 75% of asymptomatic patients).

DISCUSSION

A combined modelling approach that separates risk elements has potential to inform optimal treatment. However, our current approach is not ready for clinical application. These data support guidelines that suggest that CEA should be the preferred revascularisation modality in most patients with symptomatic carotid stenosis.

Influence of contralateral carotid artery occlusions on short- and long-term outcomes of carotid artery stenting: a retrospective single-center analysis and review of literature

BACKGROUND

In the current literature, correlations between a contralateral carotid artery occlusion (CCO) with mortality and major adverse cardiac or cerebrovascular events (MACCE) rates after carotid artery stenting (CAS) are often described with controversial conclusions. Moreover, long-term results of mortality, MACCE and restenosis rate are scarcely reported. This study examined the association between a CCO and the short- and long-term outcomes after CAS.

METHODS

One hundred and forty-six patients with CCO and without (No-CCO) who underwent between 2010 and 2017 to a CAS procedure in a single institution were retrospectively evaluated. The primary aim of the study was to evaluate mortality and MACCE rates in the short-term (defined as the occurrence during hospitalization and within 30-day) and after 3-year follow-up. The secondary aim of the study was to examine the restenosis rates in the short- and long-term period.

RESULTS

The overall success of CAS was 99.3% and the 30-day all-cause mortality rate was 0.7% (one death). About MACCE, there were no major strokes in the CCO groups and 1 (1.4%) in the No-CCO group (P=1.00). The rate of 30-day minor strokes was 1.4% (1 patient) in the CCO group and 2.7% (2 patients) in the No-CCO group (P=1.00). In the 3-year follow-up, death occurred in 11 CCO vs. 6 No-CCO patients, respectively (15.1% vs. 8.2%, P=0.30). Regarding MACCE, major stroke occurred in 6 CCO vs. 2 No-CCO patients (8.2% vs. 2.7%, P=0.27), minor stroke in 6 CCO vs. 6 No-CCO (8.2% vs. 8.2%, P=1.0) and myocardial infarction in 6 CCO (8.2%) vs. 3 No-CCO patients (8.2 vs. 4.1%, P=0.49), respectively. Regarding the 30-day restenosis rate, it was observed in one patient (1.4%) in the CCO group while no cases were recorded in the No-CCO group, respectively (P=1.00). In the 3-year follow-up, greater than >50% restenosis was observed in 7 patients (9.6%) in the CCO group and in one patient (1.4%) in the No-CCO group (P=0.06), respectively. Kaplan-Meier survival analysis revealed that CCO patients had a lower 3-year freedom from restenosis rate with respect to the No-CCO group (87.6% vs. 98.6%, P=0.024). A Cox regression model on 3-year restenosis highlighted female gender and hypertension to be statistically significant predictors of restenosis.

CONCLUSIONS

Patients with a preexisting CCO did not show a significative increased risk of procedural adverse events after CAS both in the immediate and long-term follow-up, but on the long term they are more likely to experience restenosis. CCO condition should be considered always as a clinical manifestation of a more aggressive carotid atherosclerosis.

Presence of Contralateral Carotid Occlusion Is Associated With Increased Periprocedural Stroke Risk Following CEA but Not CAS: A Meta-analysis and Meta-regression Analysis of 43 Studies and 96,658 Patients

Purpose: To investigate the prognostic role of contralateral carotid artery occlusion (CCO) in perioperative outcomes of patients undergoing carotid artery endarterectomy (CEA) vs carotid artery stenting (CAS). Materials and Methods: The PubMed, Scopus, and Cochrane databases were searched up to September 2018 to identify observational or randomized studies that compared outcomes of carotid revascularization in patients with vs without CCO. Forty-three studies (46 arms) comprising 96,658 patients were selected (75,857 CEA and 20,801 CAS). The CCO group included 9258 patients. Heterogeneity was assessed with the Higgins I² test. I²>75% indicated significant heterogeneity. A random effects model was used to account for heterogeneity among studies. The results were reported as the odds ratios (ORs) with the 95% confidence intervals (CIs). Meta-regression analysis examined potential confounders. Publication bias was quantified by the Egger method. Results: Carotid revascularization in patients with CCO was associated with an increased risk of 30-day mortality (OR 1.75, 95% CI 1.38 to 2.23, p<0.001; I²=0%), stroke (OR 1.77, 95% CI 1.41 to 2.22, p<0.001; I²=46%), transient ischemic attack (TIA) (OR 2.10, 95% CI 1.34 to 3.27, p=0.001; I²=15%), and the composite endpoint of stroke/death (OR 1.78, 95% CI 1.54 to 2.05, p<0.001; I²=0%). No difference was noted in the risk of perioperative myocardial infarction (OR 0.81, 95% CI 0.50 to 1.31; p=0.388; I²=0%). Subgroup analysis demonstrated that CEA in patients with CCO was associated with an increased risk of stroke (OR 2.07, 95% CI 1.72 to 2.49, p<0.001; I²=14%), death (OR 1.80, 95% CI 1.55 to 2.10, p<0.001; I²=0%), TIA (OR 2.18, 95% CI 1.38 to 3.45, p<0.001; I²=13%), and stroke/death (OR 1.80, 95% CI 1.55 to 2.10, p<0.001; I²=0%), whereas CCO patients who were treated with CAS were at an increased risk for death (OR 1.65, 95% CI 1.07 to 2.60, p=0.023; I²=0%) but not stroke (OR 0.94, 95% CI 0.61 to 1.47; p=0.080; I²=31%) or TIA (OR 1.18, 95% CI 0.18 to 7.55; p=0.861; I²=43%). The meta-regression analysis did not find any significant association for any of the outcomes, and there was no evidence of publication bias. Conclusion: Carotid revascularization outcomes are adversely affected by the presence of CCO. Patients with CCO have a significantly higher risk of periprocedural stroke, death, and TIA. CEA in patients with CCO is associated with an increased risk of perioperative stroke, death, TIA, and death/stroke, while CAS in the presence of a CCO is associated with an increased risk of periprocedural death but not stroke or TIA.

Risk Prediction Tools to Improve Patient Selection for Carotid Endarterectomy Among Patients With Asymptomatic Carotid Stenosis

Importance

Randomized clinical trials have demonstrated that patients with asymptomatic carotid stenosis are eligible for carotid endarterectomy (CEA) if the 30-day surgical complication rate is less than 3% and the patient's life expectancy is at least 5 years.

Objective

To develop a risk prediction tool to improve patient selection for CEA among patients with asymptomatic carotid stenosis.

Design, Setting, and Participants

In this cohort study, veterans 65 years and older who received both carotid imaging and CEA in the Veterans Administration between January 1, 2005, and December 31, 2009 (n = 2325) were followed up for 5 years. Data were analyzed from January 2005 to December 2015. A risk prediction tool (the Carotid Mortality Index [CMI]) based on 23 candidate variables identified in the literature was developed using Veterans Administration and Medicare data. A simpler model based on the number of 4 key comorbidities that were prevalent and strongly associated with 5-year mortality was also developed (any cancer in the past 5 years, chronic obstructive pulmonary disease, congestive heart failure, and chronic kidney disease [the 4C model]). Model performance was assessed using measures of discrimination (eg, area under the curve [AUC]) and calibration. Internal validation was performed by correcting for optimism using 500 bootstrapped samples.

Main Outcome and Measure

Five-year mortality.

Results

Among 2325 veterans, the mean (SD) age was 73.74 (5.92) years. The cohort was predominantly male (98.8%) and of white race/ethnicity (94.4%). Overall, 29.5% (n = 687) of patients died within 5 years of CEA. On the basis of a backward selection algorithm, 9 patient characteristics were selected (age, chronic kidney disease, diabetes, chronic obstructive pulmonary disease, any cancer diagnosis in the past 5 years, congestive heart failure, atrial fibrillation, remote stroke or transient ischemic attack, and body mass index) for the final logistic model, which yielded an optimism-corrected AUC of 0.687 for the CMI. The 4C model had slightly worse discrimination (AUC, 0.657) compared with the CMI model; however, the calibration curve was similar to the full model in most of the range of predicted probabilities.

Conclusions and Relevance

According to results of this study, use of the CMI or the simpler 4C model may improve patient selection for CEA among patients with asymptomatic carotid stenosis.

Predictive Score of Adverse Events After Carotid Endarterectomy: The NSQIP Registry Carotid Endarterectomy Scale

Background

The goal of this study was to create a comprehensive, integer‐weighted predictive scale of adverse events after carotid endarterectomy (CEA), which may augment risk stratification and patient counseling.

Methods and Results

The targeted carotid files from the prospective NSQIP (National Surgical Quality Improvement Program) registry (2011–2013) comprised the derivation population. Multivariable logistic regression evaluated predictors of a 30‐day adverse event (stroke, myocardial infarction, or death), the effect estimates of which were used to build a weighted predictive scale that was validated using the 2014 to 2015 NSQIP registry release. A total of 10 766 and 8002 patients were included in the derivation and the validation populations, in whom 4.0% and 3.7% developed an adverse event, respectively. The NSQIP registry CEA scale included 14 variables; the highest points were allocated for insulin‐dependent diabetes mellitus, high‐risk cardiac physiological characteristics, admission source other than home, an emergent operation, American Society of Anesthesiologists’ classification IV to V, modified Rankin Scale score ≥2, and presentation with a stroke. NSQIP registry CEA score was predictive of an adverse event (concordance=0.67), stroke or death (concordance=0.69), mortality (concordance=0.76), an extended hospitalization (concordance=0.73), and a nonroutine discharge (concordance=0.83) in the validation population, as well as among symptomatic and asymptomatic subgroups (P<0.001). In the validation population, patients with an NSQIP registry CEA scale score >8 and 17 had 30‐day stroke or death rates >3% and 6%, the recommended thresholds for asymptomatic and symptomatic patients, respectively.

Conclusions

The NSQIP registry CEA scale predicts adverse outcomes after CEA and can risk stratify patients with both symptomatic and asymptomatic carotid stenosis using different thresholds for each population.

Contemporary outcomes after carotid endarterectomy in high-risk anatomic and physiologic patients

OBJECTIVE

Current guidelines state that the acceptable 30-day postoperative stroke/death rate after carotid endarterectomy (CEA) is <3% for asymptomatic patients and <6% for symptomatic patients. The Centers for Medicare and Medicaid Services has identified certain high-risk characteristics used to define patients at highest risk for CEA for whom carotid artery stenting would be reimbursed. We evaluated the impact of the Centers for Medicare and Medicaid Services physiologic and anatomic high-risk criteria on major adverse event rates after CEA in asymptomatic and symptomatic patients.

METHODS

We retrospectively reviewed all patients undergoing CEA from 2011 to 2017 in the American College of Surgeons National Surgical Quality Improvement Program vascular targeted database. Patients with high-risk anatomic or physiologic characteristics were identified by a predefined variable and were compared with normal-risk patients. The primary outcome was 30-day stroke/death, stratified by symptom status.

RESULTS

We identified 25,788 patients undergoing CEA, of whom 60% were treated for asymptomatic carotid disease. Among all patients, high-risk physiology or anatomy was associated with higher rates of 30-day stroke/death compared with normal-risk patients (physiologic risk, 4.6% vs 2.3% [P < .001]; anatomic risk, 3.6% vs 2.3% [P < .001]). Patients who met criteria for high-risk physiology or anatomy also had higher rates of cardiac events (physiologic risk, 3.1% vs 1.6% [P < .001]; anatomic risk, 2.3% vs 1.6% [P < .01]), but only patients with high-risk anatomy had higher rates of cranial nerve injury (physiologic risk, 2.4% vs 2.5% [P = .81]; anatomic risk, 4.3% vs 2.5% [P < .001]). Asymptomatic patients with high-risk physiology or anatomy had higher rates of 30-day stroke/death, especially in the physiologic high-risk group (physiologic risk, 4.7% vs 1.5% [P < .001]; anatomic risk, 2.6% vs 1.5% [P < .01]), compared with normal-risk patients. However, among symptomatic patients, differences in stroke/death were seen only with high-risk anatomic patients and not with high-risk physiologic patients (physiologic risk, 4.6% vs 3.4% [P = .12]; anatomic risk, 4.8% vs 3.4% [P = .01]).

CONCLUSIONS

As currently selected, contemporary real-world outcomes after CEA in asymptomatic carotid disease patients meeting high-risk physiologic criteria show an unacceptably high 30-day stroke/death rate, well above the 3% threshold. These results suggest the need for better selection of patients and preoperative optimization before elective CEA.

Symptomatic and silent cerebral ischemia (detected on MRI) in patients with type 2 diabetes mellitus after carotid revascularization procedures

Background: Type 2 diabetes mellitus (T2DM) is a significant independent risk factor for ischaemic stroke. Carotid revascularisation procedures are an effective method of primary and secondary stroke prevention. However, patients developed postoperative acute ischaemic lesions (AILs), which were identified via magnetic resonance imaging (MRI) of the brains. Most of the patients with these AILs lack clinically overt symptoms. Aims: To assess the risk of ischaemic brain damage in patients with T2DM in the setting of carotid angioplasty with stenting (CAS) or carotid endarterectomy (CAE). Materials and methods: This open prospective study comprised of 164 patients with carotid atherosclerosis, who have undergone either CAS or CAE. Patients with T2DM were included in Group 1: 38 patients and 28 patients with CAE. Group 2 included patients without T2DM: 62 patients with CAS and 36 patients with CAE. All patients underwent a thorough neurological examination and diffusion-weighted brain MRI. In patients with T2DM, plasma glucose levels and glycated haemoglobin (HbA1c) were determined and their relationships to brain damage were evaluated. Results: In CAS, there were no statistically significant differences in the AIL frequency in patients with and without T2DM. AILs were found in 15 patients with T2DM (39.8%) and 29 patients without T2DM (46.8%, р = 0.24); three patients without T2DM were diagnosed with stroke. Of the 28 patients with T2DM who underwent CAE, 13 had AIL (46.4%); three had stroke (10.7%). In patients without T2DM, AILs were less prevalent in seven cases (19.4%, р = 0.012) and appeared asymptomatic. Following CAS, the baseline HbA1c levels were higher in patients with T2DM who developed AILs compared to those who did not develop AIL, 7.8% 1.4% vs 7.1 1.1% (р = 0.0469). Negative impact of hyperglycaemia on the risk of cerebral ischaemia was observed in patients who underwent CAE, the baseline fasting plasma glucose level was 8.5 1.9 mmol/l vs 7.0 1.5 mmol/l in patients without AIL (р = 0.014). The baseline HbA1c levels in patients with and without AILs were 8.0% 1.7% and 6.9% 0.9% respectively (р = 0.023). Conclusions: Carotid revascularisation procedure for patients with carotid atherosclerosis may be associated with risk of stroke and asymptomatic acute cerebral ischaemic lesions, which are more prevalent in patients with T2DM. Also, increased HbA1c levels is a risk factor for AIL.

Comparison of outcomes after carotid endarterectomy between type 2 diabetic and non-diabetic patients with significant carotid stenosis

BACKGROUND

We aimed to compare early and late outcomes after carotid endarterectomy (CEA) between Korean type 2 diabetic and non-diabetic patients and to investigate the impact of diabetes on the overall incidence of cardiovascular events after CEA.

METHODS

We retrospectively analyzed 675 CEAs, which were performed on 613 patients with significant carotid stenosis between January 2007 and December 2014. The CEAs were divided into a type 2 diabetes mellitus (DM) group (n = 265, 39.3%) and a non-DM group (n = 410, 60.7%). The study outcomes included the incidence of major adverse events (MAEs), defined as fatal or nonfatal stroke or myocardial infarction or all-cause mortality, during the perioperative period and within 4 years after CEA.

RESULTS

Patients in the DM and non-DM groups did not differ significantly in the incidence of MAEs or any of the individual MAE manifestations during the perioperative period. However, within 4 years after CEA, the difference in the MAE incidence was significantly greater in the DM group (P = 0.040). Analysis of the individual MAE manifestations indicated a significantly higher risk of stroke in the DM group (P = 0.006). Multivariate analysis indicated that diabetes was not associated with MAEs or individual MAE manifestations during the perioperative period, whereas within 4 years after CEA, diabetes was an independent risk factor for MAEs overall (hazard ratio [HR], 1.62; 95% confidence interval [CI] 1.06-2.48; P = 0.026) and stroke (HR, 2.55; 95% CI 1.20-5.41; P = 0.015) in particular.

CONCLUSIONS

Diabetic patients were not at greater risk of perioperative MAEs after CEA; however, the risk of late MAE occurrence was significantly greater in these patients. Within 4 years after CEA, DM was an independent risk factor for the occurrence of MAEs overall and stroke in particular.

Factors that Predict Failure to Meet Merit-Based Incentive Payment System Quality Measures for Asymptomatic Carotid Endarterectomy

BACKGROUND

The Physician Quality Reporting System (PQRS) created by the Centers for Medicare and Medicaid Services financially penalizes providers who fail to meet expected quality of care measures. The purpose of this study is to evaluate the factors that predict failure to meet PQRS measures for carotid endarterectomy (CEA).

METHODS

PQRS measure 260 (discharge by postoperative day 2 following CEA in asymptomatic patients) and 346 (rate of postoperative stroke or death following CEA in asymptomatic patients) were evaluated using hospital records from the state of Florida from 2008 to 2012. The impact of demographics, comorbidities, hospital factors, admission variables, and individual practitioner data upon timely discharge, and postoperative stroke and death. Odds ratios, 95% confidence intervals, and significance (P < 0.05) were determined through the development of a logistic regression model. Surgeons were identified by national provider identifier number, and practitioner data obtained from the American Medical Association Physician Masterfile.

RESULTS

A total of 34,235 patient records and 701 providers were identified over the 5-year period. Significant negative predictors for PQRS measure 260 included weekend admission (odds ratio [OR], 2.9), Medicaid (OR, 2.4), surgeon historical postoperative stroke rate >2.0% (OR, 1.7), African-American race (OR, 2.0), and female gender (OR, 1.3). The presence of any of these factors was associated with a 13.5% rate of failure. The most significant negative predictor for PQRS measure 346 was surgeon postoperative stroke rate >2.0% (OR, 6.2 for stroke and OR, 29.0 for death). Surgeons in this underperforming group had worse outcomes compared to their peers despite having patients with fewer risk factors for poor outcomes. Surgeon specialty, board certification, and case volume do not impact either PQRS measures.

CONCLUSIONS

Selected groups of patients and surgeons with a disproportionately high rate of postoperative stroke are at risk of failing to meet PQRS pay for performance quality measures. Awareness of these risk factors may help mitigate and minimize the risk of adversely impacting the value stream. Further evaluation of the causative factors that lead to surgeon underperformance could help to improve the quality of care.

Development of a validated model to predict 30-day stroke and 1-year survival after carotid endarterectomy for asymptomatic stenosis using the Vascular Quality Initiative

OBJECTIVE

Carotid endarterectomy (CEA) has been shown to be an effective treatment for patients with asymptomatic carotid artery stenosis when perioperative stroke rates are low and patients survive long enough to benefit from the intervention. Our objective was to develop and to validate a simple risk prediction model for 30-day stroke and 1-year mortality to guide optimal selection of patients for CEA.

METHODS

Asymptomatic patients undergoing first-time elective CEA within the Vascular Quality Initiative (VQI) from 2010 to 2015 were selected. Outcome measures included any 30-day postoperative stroke and 1-year mortality. Patient demographics, comorbidities, carotid artery disease burden, and provider characteristics were evaluated to select a parsimonious clinical model for risk prediction using multivariable logistic regression. Internal validation was performed for stroke and split sample validation was done for 1-year survival to ensure generalizability.

RESULTS

We identified 31,939 patients for inclusion in the stroke analysis (2010-2015) and 24,086 patients for the mortality analysis (2010-2014). Both the 30-day stroke rate (0.9%) and 1-year mortality rate (3.4%) varied substantially across 265 VQI centers (range, 0%-8.3% and 0%-20%, respectively). Eleven significant factors were selected for the 30-day stroke risk prediction model (area under the receiver operating characteristic curve [AUC], 0.67). Internal validation demonstrated good discrimination (bias corrected AUC = 0.652; calibration intercept and slope of 0.03 and 1.01, respectively). Similarly, 10 significant factors were selected for the 1-year mortality risk prediction model (AUC, 0.764). External validation demonstrated excellent discrimination and calibration (AUC, 0.764; 95% confidence interval, 0.72-0.80).

CONCLUSIONS

Stroke and 1-year mortality rates after CEA for asymptomatic stenosis vary across VQI centers. We have developed a preoperative risk model that can be used to accurately estimate risk of perioperative stroke and 1-year mortality and to assist providers in selecting patients with asymptomatic stenosis who are most likely to benefit from CEA.

Perioperative strokes after coronary artery bypass grafting with staged carotid endarterectomy: A nationwide perspective

STUDY OBJECTIVE

To examine the risk of perioperative stroke on in-hospital morbidity and mortality in staged coronary artery bypass grafting (CABG) and carotid endarterectomy (CEA) procedures.

DESIGN

The National Inpatient Sample (NIS) database was used to extract data on all patients who underwent staged CABG CEA procedures. They were identified using the ICD-9 (International Classification of Diseases, Ninth Revision-Clinical Modification) diagnosis and procedure codes.

SETTING

Multi-institutional.

PATIENTS

Patients who underwent staged CABG and CEA from 1999 to 2011.

INTERVENTIONS

Staged CABG and CEA procedures.

MEASUREMENTS

Various pre-operative, and perioperative risk factors and their association with in-hospital mortality and morbidity were studied.

MAIN RESULTS

The study cohort was grouped into 2761 patients who underwent staged CEA and CABG. The average age of the patient population was 69years. An in-hospital mortality of 4.96% (137) was observed. Staged procedures showed a morbidity rate of 69.21%. Patients with perioperative strokes had a mortality rate of 16.73% following staged procedures. Other notable risk factors for mortality and morbidity were post-operative myocardial infarction (MI) and congestive heart failure (CHF).

CONCLUSION

Analysis of 2761 patients over a period of 12years (1999-2011) indicate perioperative stroke to be a strong post-operative predicator of in-hospital mortality and morbidity for staged procedures. Other significant factors such as advancing age, female gender and comorbidities like CHF, left ventricular dysfunction (LVD) and post-operative MI should also be considered when determining patient risk. Further investigative studies on staged CABG and CEA procedures are needed for better patient selection and for implementing preventative strategies such as neuroprotective medication and neuromonitoring to minimize the risk of ischemic strokes.

Migraine and risk of perioperative ischemic stroke and hospital readmission: hospital based registry study

OBJECTIVE

 To evaluate whether patients with migraine are at increased risk of perioperative ischemic stroke and whether this may lead to an increased hospital readmission rate.

DESIGN

 Prospective hospital registry study.

SETTING

 Massachusetts General Hospital and two satellite campuses between January 2007 and August 2014.

PARTICIPANTS

 124 558 surgical patients (mean age 52.6 years; 54.5% women).

MAIN OUTCOME MEASURES

 The primary outcome was perioperative ischemic stroke occurring within 30 days after surgery in patients with and without migraine and migraine aura. The secondary outcome was hospital readmission within 30 days of surgery. Exploratory outcomes included post-discharge stroke and strata of neuroanatomical stroke location.

RESULTS

 10 179 (8.2%) patients had any migraine diagnosis, of whom 1278 (12.6%) had migraine with aura and 8901 (87.4%) had migraine without aura. 771 (0.6%) perioperative ischemic strokes occurred within 30 days of surgery. Patients with migraine were at increased risk of perioperative ischemic stroke (adjusted odds ratio 1.75, 95% confidence interval 1.39 to 2.21) compared with patients without migraine. The risk was higher in patients with migraine with aura (adjusted odds ratio 2.61, 1.59 to 4.29) than in those with migraine without aura (1.62, 1.26 to 2.09). The predicted absolute risk is 2.4 (2.1 to 2.8) perioperative ischemic strokes for every 1000 surgical patients. This increases to 4.3 (3.2 to 5.3) for every 1000 patients with any migraine diagnosis, 3.9 (2.9 to 5.0) for migraine without aura, and 6.3 (3.2 to 9.5) for migraine with aura. : Patients with migraine had a higher rate of readmission to hospital within 30 days of discharge (adjusted odds ratio 1.31, 1.22 to 1.41).

CONCLUSIONS

 Surgical patients with a history of migraine are at increased risk of perioperative ischemic stroke and have an increased 30 day hospital readmission rate. Migraine should be considered in the risk assessment for perioperative ischemic stroke.

Carotid Stenting Versus Carotid Endarterectomy: What Did the Carotid Revascularization Endarterectomy Versus Stenting Trial Show and Where Do We Go From Here?

Although rapidly expanding in its use, carotid artery stenting remains a relatively new procedure. Its growth is due, at least in part, to the perceived advantages of a less invasive technique. However, the clinical effectiveness and specific role for stenting in the treatment of carotid occlusive disease are still under evaluation. The primary aim of the randomized clinical trial, Carotid Revascularization Endarterectomy versus Stenting Trial (CREST), was to contrast the relative efficacy of carotid stenting versus carotid endarterectomy in preventing stroke, myocardial infarction, or death during a 30-day periprocedural period or ipsilateral stroke over the follow-up period in patients with symptomatic and asymptomatic extracranial carotid stenosis. The secondary goals were to describe the differential efficacy of the 2 procedures in men and women, contrast periprocedural (30-day) morbidity and postprocedural morbidity and mortality, estimate and contrast the restenosis rates of the 2 procedures, evaluate differences in measures of health-related quality of life and cost-effectiveness, and identify subgroups of participants at differential risk of stenting or surgery. This report summarizes the results obtained from CREST with respect to its primary and secondary aims.

Field Synopsis of the Role of Sex in Stroke Prediction Models

Background

Guidelines for stroke prevention recommend development of sex‐specific stroke risk scores. Incorporating sex in Clinical Prediction Models (CPMs) may support sex‐specific clinical decision making. To better understand their potential to guide sex‐specific care, we conducted a field synopsis of the role of sex in stroke‐related CPMs.

Methods and Results

We identified stroke‐related CPMs in the Tufts Predictive Analytics and Comparative Effectiveness CPM Database, a systematic summary of cardiovascular CPMs published from January 1990 to May 2012. We report the proportion of models including the effect of sex on stroke incidence or prognosis, summarize the directionality of the predictive effects of sex, and explore factors influencing the inclusion of sex. Of 92 stroke‐related CPMs, 30 (33%) contained a coefficient for sex or presented sex‐stratified models. Only 12/58 (21%) CPMs predicting outcomes in patients included sex, compared to 18/30 (60%) models predicting first stroke (P<0.0001). Sex was most commonly included in models predicting stroke among a general population (69%). Female sex was consistently associated with reduced mortality after ischemic stroke (n=4) and higher risk of stroke from arrhythmias or coronary revascularization (n=5). Models predicting first stroke versus outcomes among patients with stroke (odds ratio=5.75, 95% CI 2.18–15.14, P<0.001) and those developed from larger versus smaller sample sizes (odds ratio=4.58, 95% CI 1.73–12.13, P=0.002) were significantly more likely to include sex.

Conclusions

Sex is included in a minority of published CPMs, but more frequently in models predicting incidence of first stroke. The importance of sex‐specific care may be especially well established for primary prevention.

The role of unfractionated heparin for the antiaggregatory effect of aspirin in patients undergoing carotid endarterectomy: Results of an observational clinical study

The aims of the present study were to examine the influence of a low-dose unfractionated heparin regime on platelet aggregation and to additionally assess the prevalence of primary aspirin resistance in patients undergoing carotid endarterectomy. Therefore, 50 patients undergoing carotid endarterectomy were enrolled. A bolus of 3000 IU unfractionated heparin was administered 2 min before carotid cross-clamping additionally to standard antiaggregatory therapy. Haemostaseological point of care testing was performed twice, prior to surgery and 10 min after unfractionated heparin administration by the use of aggregometric and viscoelastic point of care testing. Following unfractionated heparin administration, the activated partial thromboplastin time increased significantly and clotting time in viscoelastic INTEM test was shown to be significantly prolonged. In contrast, the antiaggregatory effect of aspirin was not diminished in aggregometric ASPI test. A low-dose unfractionated heparin regime during carotid endarterectomy was therefore considered to be safe, without diminishing the antiplatelet effect of aspirin. Moreover, aggregometric point of care testing was identified to be a suitable tool for the identification of patients with primary aspirin resistance ( n = 3).

Temporal trends in safety of carotid endarterectomy in asymptomatic patients: systematic review

OBJECTIVE

To systematically review temporal changes in perioperative safety of carotid endarterectomy (CEA) in asymptomatic individuals in trial and registry studies.

METHODS

The MEDLINE and EMBASE databases were searched using the terms "carotid" and "endarterectomy" and "asymptomatic" from 1947 to August 23, 2014. Articles dealing with 50%-99% stenosis in asymptomatic individuals were included and low-volume studies were excluded. The primary endpoint was 30-day stroke or death and the secondary endpoint was 30-day all-cause mortality. Statistical analysis was performed using random-effects meta-regression for registry data and for trial data graphical interpretation alone was used.

RESULTS

Six trials (n = 4,431 procedures) and 47 community registries (n = 204,622 procedures) reported data between 1983 and 2013. Registry data showed a significant decrease in postoperative stroke or death incidence over the period 1991-2010, equivalent to a 6% average proportional annual reduction (95% credible interval [CrI] 4%-7%; p < 0.001). Considering postoperative all-cause mortality, registry data showed a significant 5% average proportional annual reduction (95% CrI 3%-9%; p < 0.001). Trial data showed a similar visual trend.

CONCLUSIONS

CEA is safer than ever before and high-volume registry results closely mirror the results of trials. New benchmarks for CEA are a stroke or death risk of 1.2% and a mortality risk of 0.4%. This information will prove useful for quality improvement programs, for health care funders, and for those re-examining the long-term benefits of asymptomatic revascularization in future trials.

[Epidemiology of cerebral perioperative vascular accidents]

OBJECTIVES

Stroke is a well-described postoperative complication, after carotid and cardiac surgery. On the contrary, few studies are available concerning postoperative stroke in general non-cardiac non-carotid surgery. The high morbid-mortality of stroke justifies an extended analysis of recent literature.

ARTICLE TYPE

Systematic review.

DATA SOURCES

Firstly, Medline and Ovid databases using combination of stroke, cardiac surgery, carotid surgery, general non-cardiac non-carotid surgery as keywords; secondly, national and European epidemiologic databases; thirdly, expert and French health agency recommendations; lastly, reference book chapters.

RESULTS

In cardiac surgery, with an incidence varying from 1.2 to 10% according to procedure complexity, stroke occurs peroperatively in 50% of cases and during the first 48 postoperative hours for the others. The incidence of stroke after carotid surgery is 1 to 20% according to the technique used as well as operator skills. Postoperative stroke is a rare (0.15% as mean, extremes around 0.02 to 1%) complication in general surgery, it occurs generally after the 24-48th postoperative hours, exceptional peroperatively, and 40% of them occurring in the first postoperative week. It concerned mainly aged patient in high-risk surgeries (hip fracture, vascular surgery). Postoperative stroke was associated to an increase in perioperative mortality in comparison to non-postoperative stroke operated patients.

CONCLUSION

Postoperative stroke is a quality marker of the surgical teams' skill and has specific onset time and induces an increase of postoperative mortality.

Clinical predictors of major adverse cardiovascular events during long-term follow-up after carotid endarterectomy

BACKGROUND

Those patients who undergo a carotid endarterectomy (CEA) will present a higher cardiovascular risk during follow-up than the general population. The objective of this study was to determine the prognostic factors and validate the accuracy of 3 cardiovascular risk scores as predictors of major adverse cardiovascular events (MACEs) during long-term follow-up after CEA.

METHODS

Observational retrospective follow-up study with 416 CEAs conducted consecutively in 385 patients from 1994 to 2011. The primary end point was MACE, single event including myocardial infarction, stroke, and cardiovascular death. Preoperative risk factors and medical treatment at discharge were collected. A general cardiovascular risk score, the Revised Cardiac Risk Index (RCRI), was used, and 2 scores specific for CEA (Halm and Tu). Descriptive analysis and Cox regression were conducted. Informed consent from patients was obtained and approval by the ethics committee.

RESULTS

The median follow-up was 4.94 years. MACEs appeared in 22.1% (95% confidence interval [CI], 18.0-26.2%) of the series during follow-up. The MACEs rate at 1 year, 3 years, and 5 years, was 3.1%, 9.3%, and 15.8%, respectively. In the Cox regression model, the MACE predictor variables were: the presence of peripheral artery disease (hazard ratio [HR], 1.69; 95% CI, 1.06-2.70) and RCRI (HR,1.61; 95% CI, 1.04-2.50). The RCRI area under the curve for predicting events, with a 2.5 cutoff point, was 0.59 with 85.9% sensitivity and a positive predictive value of 25.2%.

CONCLUSIONS

Peripheral artery disease and high RCRI have an independent effect on predicting MACEs. The 3 different scores have a low ability for predicting MACEs during long-term follow-up.

[Prediction in cerebrovascular diseases]

Prediction of the outcome of cerebrovascular diseases or of the effects and complications of various forms of treatment are essential components of all stroke treatment regimens. This review focuses on the prediction of the stroke risk in primary prevention, the prediction of the risk of secondary stroke following a transient ischemic attack (TIA), the estimation of the outcome following manifest stroke and the treatment effects, the prediction of secondary cerebrovascular events and the prediction of vascular cognitive impairment following stroke. All predictive activities in cerebrovascular disease are hindered by the translation of predictive results from studies and patient populations to the individual patient. Future efforts in genetic analyses may be able to overcome this barrier and to enable individual prediction in the area of so-called personalized medicine. In all the various fields of prediction in cerebrovascular diseases, three major variables are always important: age of the patient, severity and subtype of the stroke. Increasing age, more severe stroke symptoms and the cardioembolic stroke subtype predict a poor outcome regarding both survival and permanent disability. This finding is somewhat banal and will therefore never replace the well experienced clinician judging the chances of a patient and taking into account the personal situation of this patient, e.g. for initiation of a rehabilitation program. Besides the individualized prediction, in times of restricted economic resources and increasing tendency to clarify questions of medical treatment in court, it seems unavoidable to use prediction in economic and medicolegal interaction with clinical medicine. This tendency will be accompanied by difficult ethical problems which neurologists must be aware of. Improved prediction should not be used to allocate or restrict resources or to restrict medically indicated treatment.

The impact of patient age and comorbidities on the occurrence of "never events" in cerebrovascular surgery: an analysis of the Nationwide Inpatient Sample

OBJECT

As health care administrators focus on patient safety and cost-effectiveness, methodical assessment of quality outcome measures is critical. In 2008 the Centers for Medicare and Medicaid Services (CMS) published a series of "never events" that included 11 hospital-acquired conditions (HACs) for which related costs of treatment are not reimbursed. Cerebrovascular procedures (CVPs) are complex and are often performed in patients with significant medical comorbidities.

METHODS

This study examines the impact of patient age and medical comorbidities on the occurrence of CMS-defined HACs, as well as the effect of these factors on the length of stay (LOS) and hospitalization charges in patients undergoing common CVPs.

RESULTS

The HACs occurred at a frequency of 0.49% (1.33% in the intracranial procedures and 0.33% in the carotid procedures). Falls/trauma (n = 4610, 72.3% HACs, 357 HACs per 100,000 CVPs) and catheter-associated urinary tract infections (n = 714, 11.2% HACs, 55 HACs per 100,000 CVPs) were the most common events. Age and the presence of ≥ 2 comorbidities were strong independent predictors of HACs (p < 0.0001). The occurrence of HACs negatively impacts both LOS and hospital costs. Patients with at least 1 HAC were 10 times more likely to have prolonged LOS (≥ 90th percentile) (p < 0.0001), and 8 times more likely to have high inpatient costs (≥ 90th percentile) (p < 0.0001) when adjusting for patient and hospital factors.

CONCLUSIONS

Improved quality protocols focused on individual patient characteristics might help to decrease the frequency of HACs in this high-risk population. These data suggest that risk adjustment according to underlying patient factors may be warranted when considering reimbursement for costs related to HACs in the setting of CVPs.

Clinical prediction model suitable for assessing hospital quality for patients undergoing carotid endarterectomy

Background

Assessing hospital quality in the performance of carotid endarterectomy (CEA) requires appropriate risk adjustment across hospitals with varying case mixes. The aim of this study was to develop and validate a prediction model to assess the risk of in‐hospital stroke or death after CEA that could aid in the assessment of hospital quality.

Methods and Results

Patients from National Cardiovascular Data Registry (NCDR)'s Carotid Artery Revascularization and Endarterectomy (CARE) Registry undergoing CEA without acute evolving stroke from 2005 to 2013 were included. In‐hospital stroke or death was modeled using hierarchical logistic regression with 20 candidate variables and accounting for hospital‐level clustering. Internal validation was achieved with bootstrapping; model discrimination and calibration were assessed. A total of 213 (1.7%) primary end point events occurred during 12 889 procedures. Independent predictors of stroke or death included age, prior peripheral artery disease, diabetes mellitus, prior coronary artery disease, having a symptomatic carotid lesion, having a contralateral carotid occlusion, or having New York Heart Association Class III or IV heart failure. The model was well calibrated and demonstrated moderate discriminative ability (c‐statistic 0.65). The NCDR CEA score was then developed to support simple, prospective risk quantification in the clinical setting.

Conclusions

The NCDR CEA score, comprising 7 clinical variables, predicts in‐hospital stroke or death after CEA. This model can be used to estimate hospital risk‐adjusted outcomes for CEA and to assist with the assessment of hospital quality.

Preoperative steroid use and the risk of infectious complications after neurosurgery

BACKGROUND AND PURPOSE

The association between preoperative corticosteroid use and infectious complications after neurosurgical procedures is unclear. We aim to determine whether corticosteroids increase the risk of infectious complications after neurosurgery.

METHODS

We examined the association between preoperative corticosteroid use and postoperative infectious complications in a cohort of adults who underwent a neurosurgical procedure between 2005 and 2010 at centers participating in the National Surgical Quality Improvement Program. Corticosteroid use was defined as at least 10 days of oral or parental therapy in the 30 days prior to surgery. Our primary outcome was a composite of any infectious complications occurring within 30 days of surgery. We used propensity score analysis to examine the independent association between preoperative corticosteroid use and postoperative infections.

RESULTS

Among 26 634 neurosurgical procedures, 1228 (4.61%, 95% confidence interval [CI], 4.36-4.86) were preceded by preoperative corticosteroid use and 1469 (5.52%; 95% CI, 5.24-5.79) were followed by postoperative infections. In a propensity score analysis controlling for comorbidities, illness severity, and preexisting preoperative infections, corticosteroid use was independently associated with subsequent postoperative infections (odds ratio, 1.38; 95% CI, 1.11-1.70). Our results were unchanged in sensitivity analyses controlling for central nervous system tumors or active treatment with chemotherapy.

CONCLUSION

Our results suggest that preoperative corticosteroid use is associated with an increased risk of infectious complications after neurosurgery. These findings may aid physicians with preoperative treatment decisions and risk stratification. Future randomized trials are needed to guide preoperative use of corticosteroids in this population.

Anisotropic diffusion filter based edge enhancement for the segmentation of carotid intima-media layer in ultrasound images using variational level set method without re-initialisation

In this work an attempt has been made to enhance the edges and segment the boundary of intima-media layer of Common Carotid Artery (CCA) using anisotropic diffusion filter and level set method. Ultrasound B mode longitudinal images of normal and abnormal images of common carotid arteries are used in this study. The images are subjected to anisotropic diffusion filter to generate edge map. This edge map is used as a stopping boundary in variational level set method without re-initialisation to segment the intima-media layer. Geometric features are extracted from this layer and analyzed statistically. Results show that anisotropic diffusion filtering is able to extract the edges in both normal and abnormal images. The obtained edge maps are found to have high contrast and sharp edges. The edge based variational level set method is able to segment the intima-media layer precisely from common carotid artery. The extracted geometrical features such as major axis and extent are found to be statistically significant in differentiating normal and abnormal images. Thus this study seems to be clinically useful in diagnosis of cardiovascular disease.

Carotid endarterectomy in octogenarian: short- and midterm results

BACKGROUND

Randomized controlled trials that have established recommendations for carotid surgery have excluded patients >79 years of age, and in our day to day practice, patients in this age group are becoming more common. We sought to analyze the outcomes of carotid endarterectomy (CEA) in octogenarians, determine the risk factors of morbidity and mortality, and evaluate the midterm survey of these patients.

METHODS

Age was the only selection criteria for inclusion in this study. We compared symptomatic and asymptomatic populations and retrospectively analyzed the CEA results performed in patients ≥80 years of age in each group. We calculated the combined ipsilateral stroke/death for each group.

RESULTS

In the 6-year study period (2002-2007), 132 CEAs were performed in 118 octogenarians. The mean age was 83.2 years (range: 80-93), and there were 70 men (59.3%) and 48 women (40.6%). In this study group, 37.9% of patients were symptomatic and 62.1% were asymptomatic; the rate of internal carotid stenosis was 81.6% (standard deviation: ±8.5%). The combined ipsilateral stroke/death rate was 3.79% (4 deaths and 1 stroke): 2% in the symptomatic patients and 4.88% in the asymptomatic patients. No differences were found between the groups' combined ipsilateral stroke/death rate (P > 0.05), but there were significant more patients with coronary artery disease and peripheral artery disease in the asymptomatic patients. A contralateral significant internal carotid stenosis was a risk factor of combined ipsilateral stroke and death (P = 0.024). The mean duration of follow-up was 3.8 ± 2.0 years, and 73% ± 5% of the patients were alive at 3 years.

CONCLUSION

The good immediate results and good probability of survival at 3 years after surgery conveys a real benefit of this surgery in this age group, but patients should be selected on a case by case basis. In our experience, the presence of bilateral lesions should be a significant influence criterion in the preoperative risk assessment. Other evaluation criteria, such as cardiac status, are needed to optimize the selection of asymptomatic patients in particular.

Applying the payoff time framework to carotid artery disease management

BACKGROUND

and

OBJECTIVE

Asymptomatic stenosis of the carotid arteries is associated with stroke. Carotid revascularization can reduce the future risk of stroke but can also trigger an immediate stroke. The objective was to model the generic relationship between immediate risk, long-term benefit, and life expectancy for any one-time prophylactic treatment and then apply the model to the use of revascularization in the management of asymptomatic carotid disease.

METHODS

In the "payoff time" framework, the possibility of losing quality-adjusted life-years (QALYs) because of revascularization failure is conceptualized as an "investment" that is eventually recouped over time, on average. Using this framework, we developed simple mathematical forms that define relationships between the following: perioperative probability of stroke (P); annual stroke rate without revascularization (r0); annual stroke rate after revascularization, conditional on not having suffered perioperative stroke (r1); utility levels assigned to the asymptomatic state (ua) and stroke state (us); and mortality rates (λ).

RESULTS

In patients whose life expectancy is below a critical life expectancy (CLE = P/(1-P)r0-r1, the "investment" will never pay off, and revascularization will lead to loss of QALYs, on average. CLE is independent of utilities assigned to the health states if a rank ordering exists in which ua > us. For clinically relevant values (P = 3%, r0 = 1%, r1 = 0.5%), the CLE is approximately 6.4 years, which is longer than published guidelines regarding patient selection for revascularization.

CONCLUSIONS

In managing asymptomatic carotid disease, the payoff time framework specifies a CLE beneath which patients, on average, will not benefit from revascularization. This formula is suitable for clinical use at the patient's bedside and can account for patient variability, the ability of clinicians who perform revascularization, and the particular revascularization technology that is chosen.

Contralateral carotid occlusion in endovascular and surgical carotid revascularization: a single centre experience with literature review and meta-analysis

OBJECTIVE/BACKGROUND

The influence of contralateral carotid occlusion (CCO) on the outcome of carotid endarterectomy (CEA) and stenting (CAS) is debated. This study aims to evaluate CEA and CAS results in patients with CCO.

METHODS

All carotid revascularizations from 2005 to 2011 were analyzed, focusing on the role of CCO on 30-day cerebral events and death (CED). A meta-analysis was performed to evaluate the results of the literature by random effect.

RESULTS

Of the 1,218 carotid revascularizations performed in our institution, 706 (57.9%) were CEA and 512 (42.1%) were CAS. CED occurred in 3.6% of the CEAs and 8.2% of the CASs (p = .001). CCO was present in 37 (5.2%) CEAs and 38 (7.4%) CASs. In CEA, CCO patients had a higher CED compared with the non-CCO patients (16.2% vs. 2.9%, p = .001), as confirmed by multiple regression analysis (OR [odds ratio]: 5.1[1.7-14.5]). In CAS, CED was not significantly different in the CCO and non-CCO patients (2.6% vs. 8.7%, p = 0.23). The comparative analysis of the CCO patients showed a higher CED in CEA compared with that in CAS (16.2% vs. 2.6%, p = 0.04). Meta-analysis of 33 papers (27 on CEA and 6 on CAS) revealed that CCO was associated with a higher CED in CEA, but not in CAS (OR: 1.82 [1.57-2.11]; OR: 1.22 [0.60-2.49], respectively).

CONCLUSION

CCO can be considered as a risk factor for CED in CEA, but not in CAS. CAS appears to be associated with lower CED than CEA in CCO patients.

Optimal selection of asymptomatic patients for carotid endarterectomy based on predicted 5-year survival

OBJECTIVE

Although carotid endarterectomy (CEA) is performed to prevent stroke, long-term survival is essential to ensure benefit, especially in asymptomatic patients. We examined factors associated with 5-year survival following CEA in patients with asymptomatic internal carotid artery (ICA) stenosis.

METHODS

Prospectively collected data from 4114 isolated CEAs performed for asymptomatic stenosis across 24 centers in the Vascular Study Group of New England between 2003 and 2011 were used for this analysis. Late survival was determined with the Social Security Death Index. Cox proportional hazard models were used to identify risk factors for mortality within the first 5 years after CEA and to calculate a risk score for predicting 5-year survival.

RESULTS

Overall 3- and 5-year survival after CEA in asymptomatic patients were 90% (95% CI 89%-91%) and 82% (95% CI 81%-84%), respectively. By multivariate analysis, increasing age, diabetes, smoking history, congestive heart failure, chronic obstructive pulmonary disease, poor renal function (estimated glomerular filtration rate <60 or dialysis dependence), absence of statin use, and worse contralateral ICA stenosis were all associated with worse survival. Patients classified as low (27%), medium (68%), and high risk (5%) based on number of risk factors had 5-year survival rates of 96%, 80%, and 51%, respectively (P < .001).

CONCLUSIONS

More than four out of five asymptomatic patients selected for CEA in the Vascular Study Group of New England achieved 5-year survival, demonstrating that, overall, surgeons in our region selected appropriate patients for carotid revascularization. However, there were patients selected for surgery with high risk profiles, and our models suggest that the highest risk patients (such as those with multiple major risk factors including age ≥ 80, insulin-dependent diabetes, dialysis dependence, and severe contralateral ICA stenosis) are unlikely to survive long enough to realize a benefit of prophylactic CEA for asymptomatic stenosis. Predicting survival is important for decision making in these patients.

In-hospital versus postdischarge adverse events following carotid endarterectomy

OBJECTIVE

Most studies based on state and nationwide registries evaluating perioperative outcome after carotid endarterectomy (CEA) rely on hospital discharge data only. Therefore, the true 30-day complication risk after carotid revascularization may be underestimated.

METHODS

We used the National Surgical Quality Improvement Program database 2005-2010 to assess the in-hospital and postdischarge rate of any stroke, death, cardiac event (new Q-wave myocardial infarction or cardiac arrest), and combined stroke/death and combined adverse outcome (S/D/CE) at 30 days following CEA. Multivariable analyses were used to identify predictors for in-hospital and postdischarge events separately, and in particular, those that predict postdischarge events distinctly.

RESULTS

A total of 35,916 patients who underwent CEA during 2005-2010 were identified in the National Surgical Quality Improvement Program database; 59% were male, median age was 72 years, and 44% had a previous neurologic event. Thirty-day stroke rate was 1.6% (n = 591), death rate was 0.8% (n = 272), cardiac event rate was 1.0% (n = 350), stroke or death rate was 2.2% (n = 794), and combined S/D/CE rate was 2.9% (n = 1043); 33% of strokes, 53% of deaths, 32% of cardiac events, 40% of combined stroke/death, and 38% of combined S/D/CE took place after hospital discharge. Patients with a prior stroke or transient ischemic attack had similar proportions of postdischarge events compared with patients without prior symptoms. Independent predictors for postdischarge events, but not for in-hospital events were female sex (stroke [odds ratio (OR), 1.6; 95% confidence interval (CI), 1.2-2.1] and stroke/death [OR, 1.4; 95% CI, 1.1-1.7]), renal failure (stroke [OR, 3.0; 95% CI, 1.4-6.2]) and chronic obstructive pulmonary disease (death [OR, 2.5; 95% CI, 1.6-3.7], stroke/death [OR, 1.8; 95% CI, 1.4-2.4], and S/D/CE [OR 1.8, 95% CI 1.4-2.3]).

CONCLUSIONS

With 38% of perioperative adverse events after CEA happening posthospitalization, regardless of symptoms status, we need to be alert to the ongoing risks after discharge particularly in women, patients with renal failure, or chronic obstructive pulmonary disease. This emphasizes the need for reporting and comparing 30-day adverse event rates when evaluating outcomes for CEA, or comparing carotid stenting to CEA.

Race as a predictor of morbidity, mortality, and neurologic events after carotid endarterectomy

OBJECTIVE

Racial disparities in the outcomes of patients undergoing carotid endarterectomy (CEA) have been reported. We sought to examine the contemporary relationship between race and outcomes and to report postdischarge events after CEA.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program Participant Use Data Files were reviewed to identify all CEAs performed from 2005 to 2010 by vascular surgeons. The influence of race on outcomes was examined. Multivariate analysis was performed using variables found to be significant on bivariate analysis. The primary outcomes were stroke and mortality. Secondary outcomes were other 30-day complications, including postdischarge events.

RESULTS

CEA was performed on 29,114 white patients (95.7%) and on 1316 black patients (4.3%); the overall stroke and mortality rates were 1.65% and 0.7%, respectively. The stroke rate was 1.6% for whites and 2.5% blacks (P = .009). The 30-day mortality rate was 0.7% for whites and 1.4% for blacks (P = .002). There was a longer operating time (P < .001) and total length of stay (P < .001), more postoperative pneumonias (P = .049), unplanned intubations (P < .001), ventilator dependence (P < .001), cardiac arrests (P < .001), bleeding requiring transfusions (P = .024), and reoperations within 30 days (P = .021) among black patients. Multivariate logistic regression modeling identified black race as an independent risk factor for 30-day mortality (odds ratio, 1.9; P = .007). Black patients also had a greater proportion of in-hospital deaths than white patients (73.7% vs 43.1%; P = .01). There was no between-group difference in the rate of postdischarge strokes. Thirty-six percent of all strokes occurred after discharge at a mean of 8.3 days, and 54.3% of deaths occurred after discharge at a mean of 11 days.

CONCLUSIONS

Black race is an independent risk factor for 30-day mortality after CEA. A significant proportion of strokes and deaths occur after discharge in both racial groups evaluated.

Silent coronary artery disease in Japanese patients undergoing carotid artery stenting

BACKGROUND

The aim of this retrospective study was to determine the prevalence of silent coronary artery disease (CAD) and the risk factors associated with concomitant CAD in Japanese patients undergoing carotid artery stenting (CAS).

METHODS

The records of 112 consecutive patients (99 men and 13 women; mean age 70 ± 8 years) who underwent elective CAS at our institution for extracranial carotid artery stenosis between January 2006 and January 2011 were reviewed retrospectively. During this period, preoperative CAD screening by coronary angiography was performed in all patients. Patients were diagnosed with CAD when ≥ 1 coronary arteries had stenosis ≥ 75% and were classified into 2 groups: (1) a group with CAD that was based on preoperative coronary angiography or a history of percutaneous coronary intervention (PCI) and/or coronary artery bypass grafting (CABG), and (2) a group without CAD that had no angiographically documented stenosis ≥ 75%.

RESULTS

Sixteen (14.3%) patients had CAD that had already been treated by PCI and/or CABG. Silent CAD was detected in 39 (34.8%) of 112 patients. Taken together, 55 (49.1%) patients had clinically significant CAD. The patients with CAD were more likely to have diabetes mellitus (DM; P = .001), dyslipidemia (P = .013), and bilateral carotid disease (P = .033). Multivariate analysis revealed that DM (odds ratio 3.07; 95% confidence interval 1.25-7.53) and bilateral carotid stenosis (odds ratio 2.72; 95% confidence interval 1.10-6.75) were independent variables associated with concomitant CAD.

CONCLUSIONS

Perioperative CAD screening revealed that silent CAD was frequently diagnosed in Japanese patients scheduled for CAS, particularly in those with DM and/or bilateral carotid stenosis.

Risk index for predicting perioperative stroke, myocardial infarction, or death risk in asymptomatic patients undergoing carotid endarterectomy

OBJECTIVE

The latest guidelines recommend performance of carotid endarterectomy (CEA) on asymptomatic patients with high-grade carotid stenosis, only if the combined perioperative stroke, myocardial infarction (MI), or death risk is ≤3%. Our objective was to develop and validate a risk index to estimate the combined risk of perioperative stroke, MI, or death in asymptomatic patients undergoing elective CEA.

METHODS

Asymptomatic patients who underwent an elective CEA (n = 17,692) were identified from the 2005-2010 National Surgical Quality Improvement Program, a multicenter, prospective database. Multivariable logistic regression analysis was performed with primary outcome of interest being the composite of any stroke, MI, or death during the 30-day periprocedural period. Bootstrapping was used for internal validation. A risk index was created by assigning weighted points to each predictor using the β-coefficients from the regression analysis.

RESULTS

Fifty-eight percent of the patients were men with a median age of 72 years. Thirty-day incidences of stroke, MI, and death were 0.9% (n = 167), 0.6% (n = 108), and 0.4% (n = 72), respectively. The combined 30-day stroke, MI, or death incidence was 1.8% (n = 324). On multivariable analysis, six independent predictors were identified and a risk index created by assigning weighted points to each predictor using the β-coefficients from the regression analysis. The predictors included age in years (<60: 0 point; 60-69: -1 point; 70-79: -1 point; ≥80: 2 points), dyspnea (2 points), chronic obstructive pulmonary disease (3 points), previous peripheral revascularization or amputation (3 points), recent angina within 1 month (4 points), and dependent functional status (5 points). Patients were classified as low (<3%), intermediate (3%-6%), or high (>6%) risk for combined 30-day stroke, MI, or death, based on a total point score of <4, 4-7, and >7, respectively. There were 15,249 patients (86.2%) in the low-risk category, 2233 (12.6%) in the intermediate-risk category, and 210 (1.2%) in the high-risk category.

CONCLUSIONS

The validated risk index can help identify asymptomatic patients who are at greatest risk for 30-day stroke, MI, and death after CEA, thereby aiding patient selection.

Carotid endarterectomy in asymptomatic patients with limited life expectancy

BACKGROUND AND PURPOSE

Data from randomized trials assert that asymptomatic patients undergoing carotid endarterectomy (CEA) must live 3 to 5 years to realize the benefit of surgery. We examined how commonly CEA is performed among asymptomatic patients with limited life expectancy.

METHODS

Within the American College of Surgeons National Quality Improvement Project we identified 8 conditions associated with limited life expectancy based on survival estimates using external sources. We then compared rates of 30-day stroke, death, and myocardial infarction after CEA between asymptomatic patients with and without life-limiting conditions.

RESULTS

Of 12,631 CEAs performed in asymptomatic patients, 2525 (20.0%) were in patients with life-limiting conditions or diagnoses. The most common conditions were severe chronic obstructive pulmonary disease and American Society of Anesthesiologists Class IV designation. Patients with life-limiting conditions had significantly higher rates of perioperative complications, including stroke (1.8% versus 0.9%, P<0.001), death (1.4% versus 0.3%, P<0.001), and stroke/death (2.9% versus 1.1%, P<0.001). Even after adjustment for other comorbidities, patients with life-limiting conditions were nearly 3 times more likely to experience perioperative stroke or death than those without these conditions (OR, 2.8; 95% CI, 2.1-3.8; P<0.001).

CONCLUSION

CEA is performed commonly in asymptomatic patients with life-limiting conditions. Given the high rates of postoperative stroke/death in these patients as well as their limited life expectancy, the net benefit of CEA in this population remains uncertain. Health policy research examining the role of CEA in asymptomatic patients with life-limiting conditions is necessary and may serve as a potential source for significant healthcare savings in the future.

Comparison of carotid endarterectomy and stenting in real world practice using a regional quality improvement registry

OBJECTIVE

Carotid artery stenting (CAS) vs endarterectomy (CEA) remains controversial and has been the topic of recent randomized controlled trials. The purpose of this study was to compare the practice and outcomes of CAS and CEA in a real world setting.

METHODS

This is a retrospective analysis of 7649 CEA and 430 CAS performed at 17 centers from 2003 to 2010 within the Vascular Study Group of New England (VSGNE). The primary outcome measures were (1) any in-hospital stroke or death and (2) any stroke, death, or myocardial infarction (MI). Patients undergoing CEA in conjunction with cardiac surgery were excluded. Multivariate logistic regression was performed to identify predictors of stroke or death in patients undergoing CAS.

RESULTS

CEA was performed in 17 centers by 111 surgeons, while CAS was performed in 6 centers by 30 surgeons and 8 interventionalists. Patient characteristics varied by procedure. Patients undergoing CAS had a higher prevalence of coronary artery disease, congestive heart failure, diabetes, and prior ipsilateral CEA. Embolic protection was used in 97% of CAS. Shunts were used in 48% and patches in 86% of CEA. The overall in-hospital stroke or death rate was higher among patients undergoing CAS (2.3% vs 1.1%; P = .03). Overall stroke, death, or MI (2.8% CAS vs 2.1% CEA; P = .32) were not different. Asymptomatic patients had similar rates of stroke or death (CAS 0.73% vs CEA 0.89%; P = .78) and stroke, death, or MI (CAS 1.1% vs CEA 1.8%; P = .40). Symptomatic patients undergoing CAS had higher rates of stroke or death (5.1% vs 1.6%; P = .001), and stroke, death, or MI (5.8% vs 2.7%; P = .02). By multivariate analysis, major stroke (odds ratio, 4.5; 95% confidence interval [CI], 1.9-10.8), minor stroke (2.7; CI, 1.5-4.8), prior ipsilateral CEA (3.2, CI, 1.7-6.1), age >80 (2.1; CI, 1.3-3.4), hypertension (2.6; CI, 1.0-6.3), and a history of chronic obstructive pulmonary disease (1.6; CI, 1.0-2.4) were predictors of stroke or death in patients undergoing carotid revascularization.

CONCLUSIONS

In our regional vascular surgical practices, the overall outcomes of CAS and CEA are similar for asymptomatic patients. However, symptomatic patients treated with CAS are at a higher risk for stroke or death.

When is a peri-procedural death iatrogenic in nature?

In almost any instance of suspected iatrogenic fatality, the attending forensic pathologist faces the challenging and often daunting task in ascertaining the cause of death, determining if an iatrogenic injury had indeed occurred and if so, its contribution to the causation of death. The Forensic Medicine Division of the Health Sciences Authority in Singapore embarked on a 6 year study of such deaths to identify pertinent factors that may facilitate the assessment of iatrogenic injuries and their contribution to mortality. A total of 106 iatrogenic deaths, arising from 613 coroner's peri-procedural autopsies conducted during the period of 2005-2010 were reviewed with particular reference to the following parameters: (1) clinico-pathological correlation; (2) the length of survival; (3) the number of interventional procedures. A comprehensive analysis of these cases indicated that they could be classified into the following 3 categories, in relation to the role of clinico-pathological correlation in the ascertainment of the causes of death: (A) advantageous but not essential; (B) essential; (C) critical. A large proportion of the cases (76.5%) were assigned categories B and C. Only the minority of cases (23.6%) were assigned category A. Also, as the number of days of survival between injury and death, and the number of interventional procedures after injury increases, the greater the need for detailed clinical documentation to ascertain the cause of death.