Contemporary Results of Carotid Endarterectomy for Asymptomatic Carotid Stenosis

Vascular emergencies in neuro-ophthalmology

The cerebral vascularization is assured by the 2 internal carotids and 2 vertebral arteries, and the Willis circle.

Carotid artery obstruction is the most common abnormality associated with ocular ischemic syndrome. Obstruction may be due to atheromatous plaque, external compression, arteritis, or dissection of the artery. An atheromatous lesion of the carotid artery is the most frequent lesion responsible for ocular ischemic syndrome. The signs and symptoms of ocular ischemic syndrome are associated with severe hypoperfusion of the eye. Inflammatory lesions of the carotid artery are responsible for decreased flow in the carotid system. Other vascular emergencies are carotid artery dissection, Horton arteritis, aneurysms and carotid-cavernous fistula.

The most common ocular signs and symptoms are transient monocular blindness, persistent monocular blindness, ocular ischemia, Claude Bernard Horner syndrome and oculomotor palsies.

The carotid pathology can be a life-threatening pathology and it is important to recognize all these signs and symptoms. A multi-specialty approach will prevent misdiagnosis and lead to a better patient management.

Abbreviations: OIS = ocular ischemic syndrome, TMB = transient monocular blindness, TIA = transient ischemic attack, ESR = erythrocyte sedimentation rate, CRP = C reactive protein, NVE = neovascularization elsewhere in the retina, NVD = neovascularization on the disc, AION A = anterior ischemic arteritic optic neuropathy, CBH = Claude Bernard Horner syndrome, MRI = magnetic resonance imaging

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.

Measuring Hospital-Acquired Complications Associated With Low-Value Care

IMPORTANCE

Studies of low-value care have focused on the prevalence of low-value care interventions but have rarely quantified downstream consequences of these interventions for patients or the health care system.

OBJECTIVE

To measure immediate in-hospital harm associated with 7 low-value procedures.

DESIGN, SETTING, AND PARTICIPANTS

A cohort study with a descriptive analysis using hospital admission data from 225 public hospitals in New South Wales, Australia, was conducted from July 1, 2014, to June 30, 2017. All 9330 episodes involving 1 of 7 low-value procedures were evaluated, including endoscopy for dyspepsia in people younger than 55 years (3689 episodes); knee arthroscopy for osteoarthritis or meniscal tears (3963 episodes); colonoscopy for constipation in people younger than 50 years (665 episodes); endovascular repair of abdominal aortic aneurysm in asymptomatic, high-risk patients (508 episodes); carotid endarterectomy in asymptomatic, high-risk patients (273 episodes); renal artery angioplasty (176 episodes); and spinal fusion for uncomplicated low back pain (56 episodes). Sixteen hospital-acquired complications (HACs) were used as a measure of harm associated with low-value care.

MAIN OUTCOMES AND MEASURES

For each low-value procedure, the percentage associated with any HAC and the difference in mean length of stay for patients receiving low-value care with and without HACs were calculated.

RESULTS

Across the 225 hospitals and 9330 episodes of low-value care, rates of HACs were low for low-value endoscopy (4 [0.1%] episodes; 95% CI, 0.02%-0.2%), knee arthroscopy (18 [0.5%] episodes; 95% CI, 0.2%-0.7%), and colonoscopy (2 [0.3%] episodes; 95% CI, 0.0%-0.9%) but higher for low-value spinal fusion (4 [7.1%] episodes; 95% CI, 2.2%-11.5%), endovascular repair of abdominal aortic aneurysm (76 [15.0%] episodes; 95% CI, 11.1%-19.7%), carotid endarterectomy (21 [7.7%] episodes; 95% CI, 5.2%-10.1%), and renal artery angioplasty (15 [8.5%] episodes; 95% CI, 5.8%-11.5%). For most procedures, the most common HAC was health care-associated infection, which accounted for 83 (26.3%) (95% CI, 21.8%-31.5%) of all HACs observed. The highest rate of health care-associated infection was 8.4% (95% CI, 5.2%-11.4%) for renal artery angioplasty. For all 7 low-value procedures, median length of stay for patients with an HAC was 2 times or more the median length of stay for patients without a complication. For example, median length of stay was 1 (interquartile range [IQR], 1-1) day for knee arthroscopy with no HACs but increased to 10.5 (IQR, 1.0-21.3) days for patients with an HAC.

CONCLUSIONS AND RELEVANCE

These findings suggest that use of these 7 procedures in patients who probably should not receive them is harming some of those patients, consuming additional hospital resources, and potentially delaying care for other patients for whom the services would be appropriate. Although only some immediate consequences of just 7 low-value services were examined, harm related to all low-value procedures was noted, including high rates of harm for certain higher-risk procedures. The full burden of low-value care for patients and the health system is yet to be quantified.

Use of Antiplatelet Agents in the Neurosurgical Patient

Antiplatelet agents used to treat neurovascular disease include aspirin; P2Y12 receptor antagonists clopidogrel, prasugrel, and ticagrelor; ADP antagonist ticlopidine; phosphodiesterase inhibitor dipyridamole; and glycoprotein IIb/IIIa inhibitors abciximab, eptifibatide, and tirofiban. Numerous studies have been performed evaluating their efficacy in stroke, extracranial carotid artery disease and dissection, intracranial atherosclerotic disease, and moyamoya disease. The rapid technological advancements in endovascular neurosurgical devices have also made antiplatelet therapy a necessary part of treating intracranial aneurysms. This article presents the relevant data supporting the use of antiplatelet agents in vascular neurosurgery and recommendations based on the described studies.

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.

Ropivacaine 0.375% vs. 0.75% with prilocaine for intermediate cervical plexus block for carotid endarterectomy: A randomised trial

BACKGROUND

Carotid endarterectomy is widely performed under regional anaesthesia. Ultrasound guidance is increasingly used in many regional anaesthetic procedures to improve safety and efficacy, and because it can reduce the amount of local anaesthetic required. Despite this, an ideal approach and dosing regimen for cervical plexus block remain elusive.

OBJECTIVE

The aim of this study was to compare two different concentrations of ropivacaine in terms of analgesic adequacy, haemodynamic effects and plasma concentration using an ultrasound-guided triple approach for intermediate cervical plexus blockade.

DESIGN

A randomised, placebo-controlled, blinded study.

SETTING

University Clinic Salzburg, Department of Anaesthesiology, Perioperative Medicine and Intensive Care, Paracelsus Medical University, Salzburg, Austria, from 16 November 2012 to 17 September 2013.

PATIENTS

Forty-six patients prospectively randomised to receive ultrasound-guided intermediate cervical block with either 20 ml ropivacaine 0.75% or 20 ml ropivacaine 0.375% each with 20 ml prilocaine 1%.

INTERVENTION

After subcutaneous infiltration, blocks were performed using ultrasound-guided infiltration below the sternocleidomastoid muscle, and ultrasound-guided infiltration of the carotid sheath. Ropivacaine and prilocaine plasma concentrations were measured at intervals.

MAIN OUTCOME

The primary study endpoint was the volume of supplementary lidocaine 1% required to achieve adequate surgical anaesthesia. Perioperative haemodynamic variables and pain scores were recorded.

RESULTS

There was no statistical difference in the volume of supplementary lidocaine given: 5.0 (±3.63) ml in the ropivacaine 0.375% group and 5.17 (±2.76) ml in the ropivacaine 0.75% group (P = 0.846). Pain scores were similarly low across both groups. Measured concentrations of ropivacaine and prilocaine did not reach toxic levels in either group. Levels of ropivacaine were approximately two-fold higher in the 0.75% group [mean area under the curve (AUC) 10 531.11 (±2912.84) vs. 5264.34 ng (±1594.69), P < 0.0001]. Perioperative cardiovascular stability was excellent in both groups. There were no serious block-related complications.

CONCLUSION

An ultrasound-guided intermediate block provides adequate anaesthesia for carotid thrombendarterectomy with a little need for supplementary local anaesthetic. Use of 0.375% ropivacaine provided similarly effective analgesia as 0.75%, but resulted in significantly lower plasma concentrations.

TRIAL REGISTRATION

The study was registered at the European Clinical Trial Database (Eudra CT No.: 2012-002769) as well as at ClinicalTrials.gov (NCT01759940).

Long-term Survival after Carotid Endarterectomy in a Population with a Low Coronary Heart Disease Fatality: Implications for Decision Making

BACKGROUND

According to the current guidelines, long-term survival is an important factor influencing decision making in patients with severe asymptomatic carotid stenosis. Nevertheless, data are lacking for populations with a low incidence of coronary heart disease, the main cause of death among these patients. We aimed to assess the long-term survival after carotid endarterectomy (CEA) in a Mediterranean hospital.

METHODS

Retrospective analysis was conducted of 291 consecutive patients (main age 69 years, 78.7% men) who underwent a CEA for symptomatic (n = 147, 50.5%) or asymptomatic (n = 144, 49.5%) carotid stenosis in 2005-2014 at the Hospital del Mar (Barcelona, Spain). A Kaplan-Meier life table was done and a multivariable Cox regression model was built for the analysis of the long-term survival-associated risk factors.

RESULTS

The immediate combined mortality and/or neurological morbidity rate was 2.7%. The mean follow-up was 55 months (complete in 99.7%). During follow-up 62 patients (21.3%) died, being cancer the most frequent cause (35.5%). Cumulative 3- and 5-year survival rates were 89% and 81%, respectively. Independent risk factors (Cox regression) related to survival included age (hazards ratio [HR] 1.09, P < 0.001), an American Society of Anesthesiologists class IV score (HR 4.04, P = 0.015), and the preoperative hemoglobin value (HR 0.73, P < 0.001). The discrimination of the resulting model was 0.719 (95% confidence interval 0.644-0.794). Previous symptomatic carotid stenosis was not related to long-term survival.

CONCLUSIONS

The long-term survival of patients submitted to CEA in our series lies in the lower limit of the estimated range by other groups and is markedly related to cancer. Our study suggests that predictive models for survival are influenced by regional characteristics.

Monocyte Subsets and Related Chemokines in Carotid Artery Stenosis and Ischemic Stroke

Carotid stenosis (CS) is an important cause of ischemic stroke. However, reliable markers for the purpose of identification of high-risk, so-called vulnerable carotid plaques, are still lacking. Monocyte subsets are crucial players in atherosclerosis and might also contribute to plaque rupture. In this study we, therefore, aimed to investigate the potential role of monocyte subsets and associated chemokines as clinical biomarkers for vulnerability of CS. Patients with symptomatic and asymptomatic CS (n = 21), patients with cardioembolic ischemic strokes (n = 11), and controls without any cardiovascular disorder (n = 11) were examined. Cardiovascular risk was quantified using the Essen Stroke Risk Score (ESRS). Monocyte subsets in peripheral blood were measured by quantitative flow cytometry. Plaque specimens were histologically analyzed. Furthermore, plasma levels of monocyte chemotactic protein 1 (MCP-1) and fractalkine were measured. Intermediate monocytes (Mon2) were significantly elevated in symptomatic and asymptomatic CS-patients compared to controls. Mon2 counts positively correlated with the ESRS. Moreover, stroke patients showed an elevation of Mon2 compared to controls, independent of the ESRS. MCP-1 levels were significantly higher in patients with symptomatic than in those with asymptomatic CS. Several histological criteria significantly differed between symptomatic and asymptomatic plaques. However, there was no association of monocyte subsets or chemokines with histological features of plaque vulnerability. Due to the multifactorial influence on monocyte subsets, the usability as clinical markers for plaque vulnerability seems to be limited. However, monocyte subsets may be critically involved in the pathology of CS.

Perioperative and Long-term Outcomes of Carotid Endarterectomy for Japanese Asymptomatic Cervical Carotid Artery Stenosis: A Single Institution Study

As the recently developed medical treatments for asymptomatic cervical carotid artery stenosis (ACCAS) have shown excellent stroke prevention, carotid endarterectomy (CEA) should be carried out for more selected patients and with lower complication rates and better long-term outcomes. We have performed CEA for Japanese ACCAS patients with a uniform surgical technique and strict perioperative management. In this study, we retrospectively investigated the perioperative complications and long-term outcomes of our CEA series. A total of 147 CEAs were carried out in 139 Japanese ACCAS patients. All patients were routinely checked for their cardiac function and high risk coronary lesions were preferentially treated before CEA. All CEAs were performed under general anesthesia using a shunt system. The postoperative cerebral blood flow was routinely measured under continued sedation to prevent postoperative hyperperfusion. The 30-day perioperative morbidity rate was 2.04%, including a perioperative stroke rate of 0.68%. There were no perioperative deaths. With regard to the long-term outcomes of the 134 followed-up patients, 9 patients were dead and 5 patients suffered from strokes, including 2 patients with ipsilateral hemispheric ischemia. The annual rates of death, all stroke and ipsilateral ischemic stroke were 1.15%, 0.64%, and 0.25%, respectively. These results showed that the perioperative morbidity and mortality rates of our CEAs were lower than those in the previous large trials. Furthermore, the long-term outcomes of this series were favorable to those reported in the latest medical treatment trials for ACCAS patients. CEA may be useful for preventing ischemic stroke in Japanese ACCAS patients.

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

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

Predictors of 30-day postoperative stroke or death after carotid endarterectomy using the 2012 carotid endarterectomy-targeted American College of Surgeons National Surgical Quality Improvement Program database

OBJECTIVE

This study used a recently released procedure-targeted multicenter data source to determine independent predictors of postoperative stroke or death in patients undergoing carotid endarterectomy (CEA) for carotid artery stenosis.

METHODS

The 2012 CEA-targeted American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database was used for this study. Patient, disease, and procedure characteristics of patients undergoing CEA were assessed. Multivariate logistic regression analysis was used to determine independent risk factors for 30-day postoperative stroke/death or other major complications.

RESULTS

The analysis included 3845 patients undergoing CEA (58.1% with asymptomatic and 41.9% with symptomatic carotid disease). The overall 30-day postoperative stroke/death rate was 3.0% (1.9% in asymptomatic patients, 4.6% in symptomatic patients). The variables that maintained an independent association with postoperative stroke/death after adjustment for other known patient-related and procedure-related factors were age ≥80 years, active smoking, contralateral internal carotid artery stenosis of 80% to 99%, emergency procedure status, preoperative stroke, presence of one or more ACS NSQIP-defined high-risk characteristics (including any or all of New York Heart Association class III/IV congestive heart failure, left ventricular ejection fraction <30%, recent unstable angina, or recent myocardial infarction), and operative time ≥150 minutes.

CONCLUSIONS

After adjustment for a comprehensive array of patient-related and procedure-related variables of particular import to patients with carotid artery stenosis, we have identified several factors that are independently associated with early stroke or death after CEA. These factors are generally related to the comorbid condition of CEA patients and to specific characteristics of their carotid disease, and not to technical features of the CEA procedure. Knowledge of these factors will assist surgeons in selecting appropriate patients for this procedure.

Carotid endarterectomy under local and/or regional anesthesia has less risk of myocardial infarction compared to general anesthesia: An analysis of national surgical quality improvement program database

Multiple studies have evaluated the effect of anesthesia type on carotid endarterectomy with inconsistent results. Our study compared 30-day postoperative myocardial infarction, stroke, and mortality between carotid endarterectomy under local or regional anesthesia and carotid endarterectomy under general anesthesia utilizing National Surgical Quality Improvement Program database. All patients listed in National Surgical Quality Improvement Program database that underwent carotid endarterectomy under general anesthesia and local or regional anesthesia from 2005 to 2011 were included with the exception of patients undergoing simultaneous carotid endarterectomy and coronary artery bypass grafting. The data revealed substantial differences between the two groups compared, and these were adjusted using multiple logistic regression. Postoperative myocardial infarction, stroke, and death at 30 days were compared between the two groups. A total of 42,265 carotid endarterectomy cases were included. A total of 37,502 (88.7%) were performed under general anesthesia and 4763 (11.3%) under local or regional anesthesia. Carotid endarterectomy under local or regional anesthesia had a significantly decreased risk of 30-day postoperative myocardial infarction when compared to carotid endarterectomy under general anesthesia (0.4% vs 0.86%, p = 0.012). No statistically significant differences were found in postoperative stroke or mortality. Carotid endarterectomy under local or regional anesthesia carries a decreased risk of postoperative myocardial infarction when compared to carotid endarterectomy under general anesthesia. Therefore, patients at risk of postoperative myocardial infarction undergoing carotid endarterectomy, consideration of local or regional anesthesia may reduce that risk.

Analysis of risk factors associated with microvascular free flap failure using a multi-institutional database

BACKGROUND

There are numerous factors that may contribute to microvascular free flap failure. Although technical issues are dominant factors, patient and clinical characteristics are also contributory. The aim of this study was to investigate non-technical variables associated with microsurgical free flap failure using a multi-institutional dataset.

METHODS

Utilizing the American College of Surgeons' National Surgical Quality Improvement Program (NSQIP) database, we identified all patients who underwent microvascular free tissue transfer from 2005 through 2009. Univariate analysis was performed to determine the association of flap failure with the following factors: age, gender, ethnicity, body mass index, intraoperative transfusion, diabetes, smoking, alcohol, American Society of Anesthesiologists classification, year of operation, operative time, number of flaps, and type of reconstruction. Factors with a significance of P < 0.2 in the univariate analysis were included in the multivariate logistic regression model to identify independent risk factors.

RESULTS

A total of 639 patients underwent microsurgical free flap reconstruction with 778 flaps over the 4-year study period; 139 patients had two free flaps during the same operation. The overall incidence of flap failure was 4.4% (34/778) (95% confidence interval [CI]: 3.0%, 6.2%). Operative time was identified as an independent risk factor for free flap failure. After adjusting for other factors, those whose operative time was equal to or greater than the 75th percentile (625.5 min) were twice as likely to experience flap failure (AOR 2.09; 95% CI: 1.01-4.31; P = 0.045). None of the other risk factors studied were significant contributors.

CONCLUSIONS

In this series, the overall flap loss rate of was 4.4%. Operative time was a significant independent risk factor for flap failure.

Asymptomatic carotid stenosis: immediate revascularization or watchful waiting?

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

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.

Efficacy of Contemporary Medical Management for Asymptomatic Carotid Artery Stenosis

In the Asymptomatic Carotid Artery Stenosis trial (1995), medical management was defined as aspirin in addition to adequate control of comorbidities. Since then, medical management of asymptomatic carotid artery stenosis (CAS) has progressed to include broader use of statins. Our purpose was to review the effect of contemporary medical management on stroke prevention. A retrospective review of the Kaiser Permanente, Southern California medical group database was performed. All patients with a diagnosis of asymptomatic CAS by International Classification of Diseases, 9th Revision codes from 2007 to 2011 were identified. Intervention for stroke prevention was the criteria for exclusion. Medications used were evaluated as was the rate of stroke. Asymptomatic CAS was noted in 7255 patients. Of these, 158 (2.2%) sustained a stroke within a mean follow-up of 37 months. Patients who were taking a statin had a statistically significant lower risk of stroke (1.6 vs 3.9%). The data support that contemporary medical management of asymptomatic CAS has decreased the incidence of stroke in comparison to previously published data. The use of statins was protective against the development of stroke. Future prospective randomized trials are needed to evaluate the efficacy of carotid intervention versus current medical management.

Understanding of regional variation in the use of surgery

The use of common surgical procedures varies widely across regions. Differences in illness burden, diagnostic practices, and patient attitudes about medical intervention explain only a small degree of regional variation in surgery rates. Evidence suggests that surgical variation results mainly from differences in physician beliefs about the indications for surgery, and the extent to which patient preferences are incorporated into treatment decisions. These two components of clinical decision making help to explain the so-called surgical signatures of specific procedures, and why some consistently vary more than others. Variation in clinical decision making is, in turn, affected by broad environmental factors, including technology diffusion, supply of specialists, local training frameworks, financial incentives, and regulatory factors, which vary across countries. Better scientific evidence about the comparative effectiveness of surgical and non-surgical interventions could help to mitigate regional variation, but broader dissemination of shared decision aids will be essential to reduce variation in preference-sensitive disorders.

Ultrasonographic markers of vascular risk in patients with asymptomatic carotid stenosis

Six-hundred twenty-one subjects with unilateral asymptomatic severe internal carotid artery (ICA) stenosis were prospectively evaluated with a median follow-up of 27 months (min=6, max=68). Vascular risk profile, plaque characteristic, stenosis progression, and common carotid artery intima-media thickness (IMT) were investigated in all patients. Outcome measures were occurrence of ischemic stroke ipsilateral to ICA stenosis and vascular death, while myocardial infarction, contralateral strokes, and transient ischemic attack were considered as competing events. A total of 99 subjects (15.9%) suffered from a vascular event. Among them, 39 were strokes ipsilateral to the stenosis (6.3%). Degree of stenosis, stenosis progression, and common carotid artery IMT resulted as independent predictive factors of ipsilateral stroke. Considering a stenosis of 60% to 70% as reference, a degree between 71% and 90% increased the risk by 2.45, while a degree between 91% and 99% increased the risk by 3.26. The progression of stenosis was a strong risk factor (hazard ratio=4.32). Finally, the role of carotid IMT was confirmed as crucial additional measure, with an increased risk by 25% for each 0.1 mm IMT increase. Our data suggest that IMT, stenosis progression and severity should be considered as risk factors for cerebrovascular events in asymptomatic subjects with severe ICA stenosis.

A risk factor-based predictive model of outcomes in carotid endarterectomy: the National Surgical Quality Improvement Program 2005-2010

BACKGROUND AND PURPOSE

Accurate knowledge of individualized risks and benefits is crucial to the surgical management of patients undergoing carotid endarterectomy (CEA). Although large randomized trials have determined specific cutoffs for the degree of stenosis, precise delineation of patient-level risks remains a topic of debate, especially in real world practice. We attempted to create a risk factor-based predictive model of outcomes in CEA.

METHODS

We performed a retrospective cohort study involving patients who underwent CEAs from 2005 to 2010 and were registered in the American College of Surgeons National Quality Improvement Project database.

RESULTS

Of the 35 698 patients, 20 015 were asymptomatic (56.1%) and 15 683 were symptomatic (43.9%). These patients demonstrated a 1.64% risk of stroke, 0.69% risk of myocardial infarction, and 0.75% risk of death within 30 days after CEA. Multivariate analysis demonstrated that increasing age, male sex, history of chronic obstructive pulmonary disease, myocardial infarction, angina, congestive heart failure, peripheral vascular disease, previous stroke or transient ischemic attack, and dialysis were independent risk factors associated with an increased risk of the combined outcome of postoperative stroke, myocardial infarction, or death. A validated model for outcome prediction based on individual patient characteristics was developed. There was a steep effect of age on the risk of myocardial infarction and death.

CONCLUSIONS

This national study confirms that that risks of CEA vary dramatically based on patient-level characteristics. Because of limited discrimination, it cannot be used for individual patient risk assessment. However, it can be used as a baseline for improvement and development of more accurate predictive models based on other databases or prospective studies.

Effect of hospital-level variation in the use of carotid artery stenting versus carotid endarterectomy on perioperative stroke and death in asymptomatic patients

OBJECTIVE

Perioperative stroke and death (PSD) are more common after carotid artery stenting (CAS) than after carotid endarterectomy (CEA) in symptomatic patients, but whether this is also true in asymptomatic patients is unclear. Furthermore, use of both CEA and CAS varies geographically, suggesting possible variation in outcomes. We compared odds of PSD after CAS and CEA in asymptomatic patients to determine the impact of this variation.

METHODS

We identified CAS and CEA procedures and hospitals where they were performed from 2005 to 2009 California hospital discharge data. Preoperative symptom status and medical comorbidities were determined using administrative codes. We compared PSD rates after CAS and CEA using logistic regression and propensity score matching. We quantified hospital-level variation in the relative utilization of CAS by calculating hospital-specific probabilities of CAS use among propensity score-matched patients. We then calculated a weighted average for each hospital and used this as a predictor of PSD.

RESULTS

We identified 6053 CAS and 36,524 CEA procedures that were used to treat asymptomatic patients in 278 hospitals. Perioperative stroke and death occurred in 250 CAS and 660 CEA patients, yielding unadjusted PSD rates of 4.1% and 1.8%, respectively (P < .001). Compared with CAS patients, CEA patients were more likely to be older than 70 years (66% vs 62%; P < .001) but less likely to have three or more Elixhauser comorbidities (37% vs 39%; P < .001). Multivariate models demonstrated that CAS was associated with increased odds of PSD (odds ratio [OR], 1.865; 95% confidence interval [CI], 1.373-2.534; P < .001). Estimation of average treatment effects based on propensity scores also demonstrated 1.9% increased probability of PSD with CAS (P < .001). The average probability of receiving CAS across all hospitals and strata was 13.8%, but the interquartile range was 0.9% to 21.5%, suggesting significant hospital-level variation. In univariate analysis, patients treated at hospitals with higher CAS utilization had higher odds of PSD compared with patients in hospitals that performed CAS less (OR, 2.141; 95% CI, 1.328-3.454; P = .002). Multivariate analysis did not demonstrate this effect but again demonstrated higher odds of PSD after CAS (OR, 1.963; 95% CI, 1.393-2.765; P < .001).

CONCLUSIONS

Carotid endarterectomy has lower odds of PSD compared with CAS in asymptomatic patients. Increased utilization of CAS at the hospital level is associated with increased odds of PSD among asymptomatic patients, but this effect appears to be related to generally worse outcomes after CAS compared with CEA.

Advances in noninvasive imaging for evaluating clinical risk and guiding therapy in carotid atherosclerosis

Managing asymptomatic carotid atherosclerosis with a view to preventing ischemic stroke is a challenging task. As the annual risk of stroke in untreated asymptomatic patients on average is less than the risk of surgical intervention, the key question is how to identify those asymptomatic individuals whose risk of stroke is elevated and who would benefit from surgery, while sparing low-risk asymptomatic patients from the risks of surgical intervention. The advent of a multitude of noninvasive carotid imaging techniques offers an opportunity to improve risk stratification in patients and to monitor the response to medical therapies; assessing efficacy at individual and population levels. As part of this, plaque measurement techniques (using ultrasound, computed tomography or MRI) may be employed in monitoring plaque/component regression and progression. Novel imaging applications targeted to plaque characteristics, inflammation and neovascularization, including contrast-enhanced ultrasound and MRI, dynamic contrast-enhanced MRI, and fluorodeoxyglucose-PET, are also being explored. Ultimately, noninvasive imaging and other advances in risk stratification aim to improve and individualize the management of patients with carotid atherosclerosis.

Outcomes of carotid endarterectomy under general and regional anesthesia from the American College of Surgeons' National Surgical Quality Improvement Program

OBJECTIVE

Despite multiple studies over more than 3 decades, there still is no consensus about the influence of anesthesia type on postoperative outcomes following carotid endarterectomy (CEA). The objective of this study was to investigate whether anesthesia type, either general anesthesia (GA) or regional anesthesia (RA), independently contributes to the risk of postoperative cardiovascular complications or death using the American College of Surgeons' National Surgical Quality Improvement Program (ACS NSQIP) database.

METHODS

Retrospective analysis of elective cases of CEA from 2005 through 2009 was performed. A propensity score model using 45 covariates, including demographic factors, comorbidities, stroke history, measures of general health, and laboratory values, was used to adjust for bias and to determine the independent influence of anesthesia type on postoperative stroke, myocardial infarction (MI), and death.

RESULTS

Of 26,070 cases listed in the ACS NSQIP database, GA and RA were used in 22,054 (84.6%) and 4016 (15.4%) cases, respectively. Postoperative stroke, MI, and death occurred in 360 (1.63%), 133 (0.6%), and 154 (0.70%) patients of the GA group, respectively, and in 58 (1.44%), 11 (0.27%), and 27 (0.67%) patients of the RA group, respectively. Stratification by propensity score quintile and adjustment for covariates demonstrated GA to be a significant risk factor for postoperative MI with an adjusted odds ratio (OR) and confidence interval (CI) of 2.18 (95% CI, 1.17-4.04), P = .01 in the entire study population. The OR for MI was 5.41 (95% CI, 1.32-22.16; P = .019) in the subgroup of patients with preoperative neurologic symptoms, and 1.44 (95% CI, 0.71-2.90; P = .31) in the subgroup of patients without preoperative neurologic symptoms.

CONCLUSIONS

This analysis of a large, prospectively collected and validated multicenter database indicates that GA for CEA is an independent risk factor for postoperative MI, particularly in patients with preoperative neurologic symptoms.

Stroke prevention: an update

Stroke is a personal, familial, and social disaster. It is the third cause of death worldwide, the first cause of acquired disability, the second cause of dementia, and its cost is astronomic. The burden of stroke is likely to increase given the aging of the population and the growing incidence of many vascular risk factors. Prevention of stroke includes--as for all other diseases--a "mass approach" aiming at decreasing the risk at the society level and an individual approach, aiming at reducing the risk in a given subject. The mass approach is primarily based on the identification and treatment of vascular risk factors and, if possible, in the implementation of protective factors. These measures are the basis of primary prevention but most of them have now been shown to be also effective in secondary prevention. The individual approach combines a vascular risk factor modification and various treatments addressing the specific subtypes of stroke, such as antiplatelet drugs for the prevention of cerebral infarction in large and small artery diseases of the brain, carotid endarterectomy or stenting for tight carotid artery stenosis, and oral anticoagulants for the prevention of cardiac emboli. There is a growing awareness of the huge evidence-to-practice gap that exists in stroke prevention largely due to socio-economic factors. Recent approaches include low cost intervention packages to reduce blood pressure and cheap "polypills" combining in a single tablet aspirin and several drugs to lower blood pressure and cholesterol. Polypill intake should however not lead to abandon the healthy life-style measures which remain the mainstay of stroke prevention.

Stratifying risk: asymptomatic carotid disease

Stroke generates significant healthcare expenses and it is also a social and economic burden. The carotid artery atherosclerotic plaque instability is responsible for a third of all embolic strokes. The degree of stenosis has been deliberately used to justify carotid artery interventions in thousands of patients worldwide. However, the annual risk of stroke in asymptomatic carotid artery disease is low. Plaque morphology and its kinetics have gained ground to explain cerebrovascular and retinal embolic events. This review provides the readers with an insightful and critical analysis of the risk stratification of asymptomatic carotid artery disease in order to assist in selecting potential candidates for a carotid intervention.

Evolution of quality and surgical risk assessment in the USA

As health-care reforms progress, quality and risk assessment in the health-care system of the USA surface as critical issues. This review considers past, present and possible future changes in quality assessment along with formal programs of complication reduction and pay for performance (PFP) as related to surgery and vascular interventions. Strategies for quality improvement include aggregate and risk-adjusted outcome measurement, process compliance with the Surgical Complication Improvement Program, oversight and PFP, now policies of the Centers for Medicare and Medicaid Services (CMS). Advantages, disadvantages and unintended consequences of these policies are discussed. While ongoing system changes will influence vascular surgical practice, unique opportunities and obligations exist for vascular surgeons to contribute to quality assessment of their interventions, to evaluate long-term outcomes and to devise strategies for comprehensive cost-effective care for the conditions affecting patients with vascular disease.

Noninvasive carotid artery imaging with a focus on the vulnerable plaque

Currently carotid imaging has 2 main focuses: assessment of luminal stenosis and classification of atherosclerotic plaque characteristics. Measurement of the degree of stenosis is the main assessment used for current treatment decision making, but an evolving idea that is now driving imaging is the concept of vulnerable plaque, which is where plaque components are identified and used to define which plaques are at high risk of causing symptoms compared with those at low risk. This review article covers the methods used for noninvasive assessment of carotid luminal stenosis and the options available for plaque imaging.

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

BACKGROUND AND PURPOSE

This guideline provides an overview of the evidence on established and emerging risk factors for stroke to provide evidence-based recommendations for the reduction of risk of a first stroke.

METHODS

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association (AHA) Stroke Council Scientific Statement Oversight Committee and the AHA Manuscript Oversight Committee. The writing group used systematic literature reviews (covering the time since the last review was published in 2006 up to April 2009), reference to previously published guidelines, personal files, and expert opinion to summarize existing evidence, indicate gaps in current knowledge, and when appropriate, formulate recommendations using standard AHA criteria (Tables 1 and 2). All members of the writing group had the opportunity to comment on the recommendations and approved the final version of this document. The guideline underwent extensive peer review by the Stroke Council leadership and the AHA scientific statements oversight committees before consideration and approval by the AHA Science Advisory and Coordinating Committee.

RESULTS

Schemes for assessing a person's risk of a first stroke were evaluated. Risk factors or risk markers for a first stroke were classified according to potential for modification (nonmodifiable, modifiable, or potentially modifiable) and strength of evidence (well documented or less well documented). Nonmodifiable risk factors include age, sex, low birth weight, race/ethnicity, and genetic predisposition. Well-documented and modifiable risk factors include hypertension, exposure to cigarette smoke, diabetes, atrial fibrillation and certain other cardiac conditions, dyslipidemia, carotid artery stenosis, sickle cell disease, postmenopausal hormone therapy, poor diet, physical inactivity, and obesity and body fat distribution. Less well-documented or potentially modifiable risk factors include the metabolic syndrome, excessive alcohol consumption, drug abuse, use of oral contraceptives, sleep-disordered breathing, migraine, hyperhomocysteinemia, elevated lipoprotein(a), hypercoagulability, inflammation, and infection. Data on the use of aspirin for primary stroke prevention are reviewed.

CONCLUSIONS

Extensive evidence identifies a variety of specific factors that increase the risk of a first stroke and that provide strategies for reducing that risk.

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

BACKGROUND AND PURPOSE

National guidelines on carotid endarterectomy (CEA) for asymptomatic patients state that the procedure should be performed with a ≤ 3% risk of perioperative death or stroke. We developed and validated a multivariate model of risk of death or stroke within 30 days of CEA for asymptomatic disease and a related clinical prediction rule.

METHODS

We analyzed asymptomatic cases in a population-based cohort of CEAs performed in Medicare beneficiaries in New York State. Medical records were abstracted for sociodemographics, neurologic history, disease severity, diagnostic imaging data, comorbidities, and deaths and strokes within 30 days of surgery. We used multivariate logistic regression to identify independent predictors of perioperative death or stroke. The CEA-8 clinical risk score was derived from the final model.

RESULTS

Among the 6553 patients, the mean age was 74 years, 55% were male, 62% had coronary artery disease, and 22% had a history of distant stroke or transient ischemic attack. The perioperative rate of death or stroke was 3.0%. Multivariable predictors of perioperative events were female sex (odds ratio [OR] = 1.5; 95% CI, 1.1 to 1.9), nonwhite race (OR = 1.8; 95% CI, 1.1 to 2.9), severe disability (OR = 3.7; 95% CI, 1.8 to 7.7), congestive heart failure (OR = 1.6; 95% CI, 1.1 to 2.4), coronary artery disease (OR = 1.6; 95% CI, 1.2 to 2.2), valvular heart disease (OR = 1.5; 95% CI, 1.1 to 2.3), a distant history of stroke or transient ischemic attack (OR = 1.5; 95% CI, 1.1 to 2.0), and a nonoperated stenosis ≥ 50% (OR = 1.8; 95% CI, 1.3 to 2.3). The CEA-8 risk score stratified patients with a predicted probability of death or stroke rate from 0.6% to 9.6%.

CONCLUSIONS

Several sociodemographic, neurologic severity, and comorbidity factors predicted the risk of perioperative death or stroke in asymptomatic patients. The CEA-8 risk score can help clinicians calculate a predicted probability of complications for an individual patient to help inform the decision about revascularization.