Time to rethink management strategies in asymptomatic carotid artery disease

Carotid atherosclerotic plaque instability and cognition determined by ultrasound-measured plaque strain in asymptomatic patients with significant stenosis

OBJECTIVE This article describes the use of ultrasound measurements of physical strain within carotid atherosclerotic plaques as a measure of instability and the potential for vascular cognitive decline, microemboli, and white matter changes. METHODS Asymptomatic patients with significant (> 60%) carotid artery stenosis were studied for dynamic measures of plaque instability, presence of microemboli, white matter changes, and vascular cognitive decline in comparison with normative controls and premorbid state. RESULTS Although classically asymptomatic, these patients showed vascular cognitive decline. The degree of strain instability measured within the atherosclerotic plaque directly predicted vascular cognitive decline in these patients thought previously to be asymptomatic according to classic criteria. Furthermore, 26% of patients showed microemboli, and patients had twice as much white matter hyperintensity as controls. CONCLUSIONS These data show that physical measures of plaque instability are possible through interpretation of ultrasound strain data during pulsation, which may be more clinically relevant than solely measuring degree of stenosis. The data also highlight the importance of understanding that the definition of symptoms should not be limited to motor, speech, and vision function but underscore the role of vascular cognitive decline in the pathophysiology of carotid atherosclerotic disease. Clinical trial registration no.: NCT02476396 (clinicaltrials.gov).

Surgical and Endovascular Treatment of Extracranial Carotid Stenosis

BACKGROUND

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) can be used to prevent stroke due to arteriosclerotic lesions of the carotid artery. In Germany, legally mandated quality assurance (QA) enables the evaluation of outcome quality after CEA and CAS performed under routine conditions.

METHODS

We analyzed data on all elective CEA and CAS procedures performed over the periods 2009-2014 and 2012-2014, respectively. The endpoints of the study were the combined in-hospital stroke and death rate, stroke rate and mortality separately, local complications, and other complications. We analyzed the raw data with descriptive statistics and carried out a risk-adjusted analysis of the association of clinically unalterable variables with the risk of stroke and death. All analyses were performed separately for CEA and CAS.

RESULTS

Data were analyzed from 142 074 CEA procedures (67.8% of them in men) and 13 086 CAS procedures (69.7% in men). The median age was 72 years (CEA) and 71 years (CAS). The periprocedural rate of stroke and death after CEA was 1.4% for asymptomatic and 2.5% for symptomatic stenoses; the corresponding rates for CAS were 1.7% and 3.7%. Variables associated with increased risk included older age, higher ASA class (ASA = American Society of Anesthesiologists), symptomatic vs. asymptomatic stenosis, 50-69% stenosis, and contralateral carotid occlusion (for CEA only).

CONCLUSION

These data reveal a low periprocedural rate of stroke or death for both CEA and CAS. This study does however not permit any conclusions as to the superiority or inferiority of CEA and CAS.

Safety of Simultaneous Coronary Artery Bypass Grafting and Carotid Endarterectomy Versus Isolated Coronary Artery Bypass Grafting: A Randomized Clinical Trial

BACKGROUND AND PURPOSE

The optimal operative strategy in patients with severe carotid artery disease undergoing coronary artery bypass grafting (CABG) is unknown. We sought to investigate the safety and efficacy of synchronous combined carotid endarterectomy and CABG as compared with isolated CABG.

METHODS

Patients with asymptomatic high-grade carotid artery stenosis ≥80% according to ECST (European Carotid Surgery Trial) ultrasound criteria (corresponding to ≥70% NASCET [North American Symptomatic Carotid Endarterectomy Trial]) who required CABG surgery were randomly assigned to synchronous carotid endarterectomy+CABG or isolated CABG. To avoid unbalanced prognostic factor distributions, randomization was stratified by center, age, sex, and modified Rankin Scale. The primary composite end point was the rate of stroke or death at 30 days.

RESULTS

From 2010 to 2014, a total of 129 patients were enrolled at 17 centers in Germany and the Czech Republic. Because of withdrawal of funding after insufficient recruitment, enrolment was terminated early. At 30 days, the rate of any stroke or death in the intention-to-treat population was 12/65 (18.5%) in patients receiving synchronous carotid endarterectomy+CABG as compared with 6/62 (9.7%) in patients receiving isolated CABG (absolute risk reduction, 8.8%; 95% confidence interval, -3.2% to 20.8%; P_WALD=0.12). Also for all secondary end points at 30 days and 1 year, there was no evidence for a significant treatment-group effect although patients undergoing isolated CABG tended to have better outcomes.

CONCLUSIONS

Although our results cannot rule out a treatment-group effect because of lack of power, a superiority of the synchronous combined carotid endarterectomy+CABG approach seems unlikely. Five-year follow-up of patients is still ongoing.

CLINICAL TRIAL REGISTRATION

URL: https://www.controlled-trials.com. Unique identifier: ISRCTN13486906.

Progression of external and internal carotid artery stenosis is associated with a higher risk of ischemic neurologic events in patients with asymptomatic carotid artery stenosis

A small percentage of patients with asymptomatic carotid artery stenosis (ACAS) who are on optimal medical management do go on to develop ischemic stroke or transient ischemic attacks (IS/TIA). Several diagnostic tools have been studied to identify those patients who are at increased risk. However, most of these diagnostic tools are not available for routine clinical use or are resource intensive. We performed a retrospective study to assess the incremental value of external carotid artery stenosis progression (ECASP) along with internal carotid artery stenosis progression (ICASP) in predicting risk of ipsilateral IS/TIA in a cohort of patients with ACAS. We conducted a retrospective analysis of patients with ACAS who had at least two serial duplex ultrasounds (DUS) at our center. A total of 356 patients (712 carotid arteries) were included in the study (mean age 74.7±9 years, 49.2% male) with a mean follow-up of 60.7±32.7 months. In univariate analysis, concurrent progression of ICA and ECA stenosis on the same side arteries was associated with a very significant increased risk of ipsilateral IS/TIA (14.7% vs 4.6%, p<0.001). Also, multivariable regression analysis showed that concurrent ECA/ICA progression was an independent predictor of IS/TIA (OR=3.6, 95% CI 1.64-7.8; p=0.001). ECASP along with ICASP is significantly associated with increased risk of ipsilateral IS/TIA and provides incremental risk stratification over that provided by ICASP alone. The ECA is routinely evaluated in clinical practice, and it could serve as an additional marker for identifying higher risk patients with ACAS.

Quantification of carotid plaque lipid content with magnetic resonance T2 mapping in patients undergoing carotid endarterectomy

Background and purpose

Techniques to stratify subgroups of patients with asymptomatic carotid artery disease are urgently needed to guide decisions on optimal treatment. Reliance on estimates of % luminal stenosis has not been effective, perhaps because that approach entirely disregards potentially important information on the pathological process in the wall of the artery.

Methods

Since plaque lipid is a key determinant of plaque behaviour we used a newly validated, high-sensitivity T2-mapping MR technique for a systematic survey of the quantity and distribution of plaque lipid in patients undergoing endarterectomy. Lipid percentage was quantified in 50 carotid endarterectomy patients. Lipid distribution was tested, using two imaging indices (contribution of the largest lipid deposit towards total lipid (LLD %) and a newly-developed LAI ‘lipid aggregation index’).

Results

The bifurcation contained maximal lipid volume. Lipid percentage was higher in symptomatic vs. asymptomatic patients with degree of stenosis (DS ≥ 50%) and in the total cohort (P = 0.013 and P = 0.005, respectively). Both LLD % and LAI was higher in symptomatic patients (P = 0.028 and P = 0.018, respectively), suggesting that for a given plaque lipid volume, coalesced deposits were more likely to be associated with symptomatic events. There was no correlation between plaque volume or lipid content and degree of luminal stenosis measured on ultrasound duplex (r = -0.09, P = 0.53 and r = -0.05, P = 0.75), respectively. However, there was a strong correlation in lipid between left and right carotid arteries (r = 0.5, P <0.0001, respectively).

Conclusions

Plaque lipid content and distribution is associated with symptomatic status of the carotid plaque. Importantly, plaque lipid content was not related to the degree of luminal stenosis assessed by ultrasound. Determination of plaque lipid content may prove useful for stratification of asymptomatic patients, including selection of optimal invasive treatments.

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

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

Evaluation and Management of Atherosclerotic Carotid Stenosis

Medical therapies for the prevention of stroke have advanced considerably in the past several years. There can also be a role for mechanical restoration of the lumen by endarterectomy or stenting in selected patients with high-grade atherosclerotic stenosis of the extracranial carotid artery. Endarterectomy is generally recommended for patients with high-grade symptomatic carotid stenosis. Stenting is considered an option for patients at high risk of complications with endarterectomy. Whether revascularization is better than contemporary medical therapy for asymptomatic extracranial carotid stenosis is a subject of several ongoing randomized clinical trials in the United States and internationally.

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.

Asymptomatic Carotid Artery Stenosis: Revascularization

In patients with carotid stenosis, the most common cause of stroke is atheroembolization, and the risk is strongly related to stenosis severity and symptomatic status (stroke or transient ischemic attack within 6months). Carotid revascularization by carotid endarterectomy (CEA) or carotid artery stenting (CAS) results in plaque "passivation" by lumen enlargement, plaque removal, or plaque coverage with subsequent endothelialization. While there is considerable circumstantial evidence linking a decrease in the risk of stroke to the use of "optimal medical therapy (OMT)", the components of OMT have not been defined, and such therapy has not been rigorously evaluated in any randomized clinical trial (RCT) compared with revascularization. Studies of other vascular patients suggest that statins decrease the risk of stroke by anti-inflammatory effects, rather than cholesterol reduction. The Carotid Revascularization Endarterectomy versus Stent Trial (CREST-2) is currently randomizing standard-risk patients with asymptomatic severe carotid stenosis to OMT alone versus OMT plus CEA or CAS, but results are not expected until 2020. In the meantime, data from several "landmark" trials of CEA versus aspirin demonstrated 45-65% reduction in the 5-year risk of stroke after CEA. Several RCTs demonstrate superiority of CAS over CEA in high-risk patients (those at high-risk for CEA), and equivalence of CAS and CEA in standard-risk patients (those at acceptable risk for CEA). Compared with CEA, CAS is associated with significantly less periprocedural myocardial infarction, cranial nerve injury, and neurological injury (cranial nerve injury plus stroke); higher risk of minor stroke; and similar risk of long-term stroke. Features that increase the risk of CAS include complex aortic arch and carotid anatomy, and features that increase the risk of CEA include severe underlying cardiopulmonary disease and hostile neck anatomy; age>80years, especially those with baseline cognitive impairment, are at higher risk for stroke after CEA and CAS.

Transcranial Doppler monitoring for microemboli: a marker of a high-risk carotid plaque

In the United States, 90% of carotid intervention is being performed for asymptomatic carotid stenosis, even though 90% of patients would be better treated with intensive medical therapy. This is being justified by comparing risks of stroke or death with medical therapy during clinical trials completed decades ago (approximately 2% per year) with risks of intervention with carotid artery stenting (CAS) versus carotid endarterectomy in recent trials that did not have a medical arm. Such extrapolations are, simply put, invalid. Even though the two most recent papers comparing carotid endarterectomy with CAS reported that the long-term risk (after first deducting periprocedural risks) is similar to that with medical therapy (approximately 0.5% per year), when the periprocedural risks are considered (approximately 3% with stenting v 1.5% with CAS), most patients would be better treated with intensive medical therapy. Furthermore, it must be recognized that the low risks observed in clinical trials with highly selected surgeons and interventionalists are much lower than in real-world practice. It is therefore necessary to have ways to identify, among patients with asymptomatic carotid stenosis, the few (approximately 10% to 15%) who could benefit from intervention. Indicators of vulnerable plaque, such as ulceration, juxtaluminal lucent plaque, intraplaque hemorrhage on magnetic resonance imaging, and plaque inflammation on positron emission tomography/computed tomography are in development for that purpose. The best-validated approach is detection of microemboli on transcranial Doppler. A prospective single-center study of 468 patients showed that microemboli identified high-risk asymptomatic stenosis; this was validated by a prospective multicenter international study in 467 patients. Increased risk with microemboli persisted in the era of lower risks with intensive medical therapy. Patients with asymptomatic carotid stenosis should not be offered CAS or carotid endarterectomy without first being identified as high risk; percent stenosis does not do so. Currently, the best way to improve the risk to benefit ratio for intervention is transcranial Doppler embolus detection.

Intraoperative Completion Studies, Local Anesthesia, and Antiplatelet Medication Are Associated With Lower Risk in Carotid Endarterectomy

Background and Purpose—

In Germany, all surgical and endovascular procedures on the carotid bifurcation must be documented in a statutory nationwide quality assurance database. We aimed to analyze the association between procedural and perioperative variables and in-hospital stroke or death rates after carotid endarterectomy.

Methods—

Between 2009 and 2014, overall 142 074 elective carotid endarterectomy procedures for asymptomatic or symptomatic carotid artery stenosis were documented in the database. The primary outcome of this secondary data analysis was in-hospital stroke or death. Major stroke or death, stroke, and death, each until discharge were secondary outcomes. Adjusted relative risks (RRs) were assessed by multivariable multilevel regression analyses.

Results—

The primary outcome occurred in 1.8% of patients, with a rate of 1.4% in asymptomatic and 2.5% in symptomatic patients, respectively. In the multivariable analysis, lower risks of stroke or death were independently associated with local anesthesia (versus general anesthesia: RR, 0.85; 95% confidence interval [CI], 0.75–0.95), carotid endarterectomy with patch plasty compared with primary closure (RR, 0.71; 95% CI, 0.52–0.97), intraoperative completion studies by duplex ultrasound (RR, 0.74; 95% CI, 0.63–0.88) or angiography (RR, 0.80; 95% CI, 0.71–0.90), and perioperative antiplatelet medication (RR, 0.83; 95% CI, 0.71–0.97). No shunting and a short cross-clamp time were also associated with lower risks; however, these are suspected to be confounded.

Conclusions—

Local anesthesia, patch plasty compared with primary closure, intraoperative completion studies by duplex ultrasound or angiography, and perioperative antiplatelet medication were independently associated with lower in-hospital stroke or death rates after carotid endarterectomy.

Appropriate Patient Selection for Carotid Revascularization Procedures is Urgently Needed

The identification/selection of appropriate patient subgroups with asymptomatic carotid artery stenosis and the performance of prophylactic carotid endarterectomy (CEA)/carotid artery stenting (CAS) exclusively on these asymptomatic patient subgroups is currently one of the "hottest" topics in vascular surgery. It is now clear that offering CEA/CAS to asymptomatic carotid patients based only on the degree of carotid stenosis is unjustified and scientifically flawed. On the other hand, offering only best medical therapy to every asymptomatic patient, irrespective of certain high-risk criteria (such as the detection of microemboli by transcranial Doppler, intraplaque hemorrhage, silent embolic infarcts on brain computed tomography/magnetic resonance imaging, elevated biomarkers, family history), is equally wrong. The validation of specific measures to identify those asymptomatic patients at high risk for developing symptoms is crucial to achieve optimal use of carotid interventions and avoid wasting stroke prevention resources.

Study of carotid disease in patients with peripheral artery disease

OBJECTIVE

To study the stenosis of the carotid arteries in patients with symptomatic peripheral arterial disease.

METHODS

we assessed 100 consecutive patients with symptomatic peripheral arterial disease in stages of intermittent claudication, rest pain or ulceration. Carotid stenosis was studied by echo-color-doppler, and considered significant when greater than or equal to 50%. We used univariate analysis to select potential predictors of carotid stenosis, later taken to multivariate analysis.

RESULTS

The prevalence of carotid stenosis was 84%, being significant in 40% and severe in 17%. The age range was 43-89 years (mean 69.78). Regarding gender, 61% were male and 39% female. Half of the patients had claudication and half had critical ischemia. Regarding risk factors, 86% of patients had hypertension, 66% exposure to smoke, 47% diabetes, 65% dyslipidemia, 24% coronary artery disease, 16% renal failure and 60% had family history of cardiovascular disease. In seven patients, there was a history of ischemic cerebrovascular symptoms in the carotid territory. The presence of cerebrovascular symptoms was statistically significant in influencing the degree of stenosis in the carotid arteries (p = 0.02 at overall assessment and p = 0.05 in the subgroups of significant and non-significant stenoses).

CONCLUSION

the study of the carotid arteries by duplex scan examination is of paramount importance in the evaluation of patients with symptomatic peripheral arterial disease, and should be systematically conducted in the study of such patients.

Impact of Clinical Trial Results on the Temporal Trends of Carotid Endarterectomy and Stenting From 2002 to 2014

Supplemental Digital Content is available in the text.

Background and Purpose—

Randomized trials provide conflicting data for the efficacy of carotid-artery stenting compared with endarterectomy. The purpose of this study was to examine the impact of conflicting clinical trial publications on the utilization rates of carotid revascularization procedures.

Methods—

We conducted a population-level time-series analysis of all individuals who underwent carotid endarterectomy and stenting in Ontario, Canada (2002–2014). The primary analysis examined temporal changes in the rates of carotid revascularization procedures after publications of major randomized trials. Secondary analyses examined changes in overall and age, sex, carotid-artery symptom, and operator specialty–specific procedure rates.

Results—

A total of 16 772 patients were studied (14 394 endarterectomy [86%]; 2378 stenting [14%]). The overall rate of carotid revascularization decreased from 6.0 procedures per 100 000 individuals ≥40 years old in April 2002 to 4.3 procedures in the first quarter of 2014 (29% decrease; P<0.001). The rate of endarterectomy decreased by 36% (P<0.001), whereas the rate of carotid-artery stenting increased by 72% (P=0.006). We observed a marked increase (P=0.01) in stenting after publication of the SAPPHIRE trial (Stenting and Angioplasty With Protection in Patients at High Risk for Endarterectomy) in 2004, whereas stenting remained relatively unchanged after subsequent randomized trials published in 2006 (P=0.11) and 2010 (P=0.34). In contrast, endarterectomy decreased after trials published in 2006 (P=0.04) and 2010 (P=0.005).

Conclusions—

Although the overall rates of carotid revascularization and endarterectomy have fallen since 2002, the rate of carotid-artery stenting has risen since the publication of stenting-favorable SAPPHIRE trial. Subsequent conflicting randomized trials were associated with a decreasing rate of carotid endarterectomy.

The relationship between preoperative serum cortisol level and the stability of plaque in carotid artery stenosis patients undergoing carotid endarterectomy

BACKGROUND

Stability of plaque has been implicated as risk factor for stroke. Serum cortisol regulates lipoprotein metabolism and immune response, contributing to plaque stability in atherosclerosis. However, the relationship between serum cortisol and stability of carotid plaque has not been well characterized. We conducted a serology analysis to identify the relationship between serum cortisol and carotid plaque stability.

METHODS

Between May 2013 to October 2015, 73 patients with carotid stenosis patients undergoing carotid endarterectomy (CEA) were enrolled in our study. Serum cortisol was analyzed at 8:00 AM in the morning before surgery via liquid chromatography tandem mass spectrometry. According to the classification made by the American Heart Association, hematoxylin-and-eosin staining was performed to divide these patients into either a stable or unstable group, according to the morphology of fibrous cap, lipid core and intima layer. A curve fitting method was used to identify the relationship between preoperative serum cortisol and stability of carotid plaque. Univariate and multivariate logistic regression analysis were used to identify carotid plaque stability-associated serum cortisol.

RESULTS

Curve fitting's result represents a U-shape characteristic. A total of 314.92 and 395.23 nmol/L were considered as the cut point for preoperative serum cortisol when trisected the patients. When adjusted for degree of stenosis, hyperlipemia, smoking and low-density lipoprotein (LDL), univariate and multivariate logistic regression analysis' results demonstrated that preoperative serum cortisol can significantly affect carotid plaque stability. The odds ratio values in multivariate logistic regression analysis for C reactive protein (CRP), white blood cell (WBC), interleukin-6 (IL-6) and preoperative serum cortisol level were 7.67 and 20.86 respectively.

CONCLUSIONS

Preoperative serum cortisol was associated with stability of carotid plaque in patients undergoing CEA. Low or high levels of preoperative serum cortisol might be an adverse factor for carotid plaque stability.

Recent advances in pathogenesis, assessment, and treatment of atherosclerosis

In recent years, there have been a number of advances in the pathogenesis and treatment of atherosclerosis and in assessing prognosis in carotid atherosclerosis. Risk stratification to improve vascular prevention by identifying patients most likely to benefit from intensive therapy is much improved by measuring carotid plaque burden. In patients with asymptomatic carotid stenosis, a number of modalities can be used to identify the 10-15% who could benefit from endarterectomy or stenting. Transcranial Doppler embolus detection, echolucency and ulceration on 3D ultrasound, intraplaque hemorrhage on magnetic resonance imaging (MRI), and reduced cerebrovascular reserve are useful already; new approaches including plaque texture on ultrasound and imaging of plaque inflammation and early calcification on positron emission tomography/computed tomography (PET/CT) are in development. The discovery that the intestinal microbiome produces vasculotoxic metabolites from dietary constituents such as carnitine in meat (particularly red meat) and phosphatidylcholine from egg yolk and other sources has revolutionized nutritional aspects of vascular prevention. Because many of these vasculotoxic metabolites are removed by the kidney, it is particularly important in patients with renal failure to limit their intake of red meat and egg yolk. A new approach to lowering low-density lipoprotein (LDL) cholesterol by blocking the action of an enzyme that destroys LDL receptors promises to revolutionize vascular prevention once less costly treatments are developed, and a new approach to vascular prevention—“treating arteries instead of risk factors”—shows promise but requires randomized trials. These advances all promise to help in the quest to prevent strokes in high-risk patients.

Transcranial Doppler Emboli Identifies Asymptomatic Carotid Patients at High Stroke Risk: Why This Technique Should be Used More Widely

With modern intensive medical therapy, the annual risk of ipsilateral stroke in asymptomatic carotid stenosis (ACS) is now ∼0.5%. Therefore, even the relative low risks reported from the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) trial do not justify routine intervention in most (90%) of the patients with ACS. It is therefore necessary to identify the ∼10% to15% of patients with ACS who have a stroke risk high enough to justify intervention. Transcranial Doppler (TCD) embolus detection has been shown in 2 prospective studies (one with 468 patients and the other with 467 patients) to identify patients at high risk and distinguish them from those who would be better served by medical therapy. There is no valid reason why carotid intervention should be carried out in ACS without first identifying that the patient's risk of stroke is higher than the risk of intervention. The best validated way to do this is by TCD embolus detection, and the cost of TCD equipment and training is approximately the same as the cost of 2 carotid stenting procedures in the United States. This procedure should be used more widely.

Appropriate management of asymptomatic carotid stenosis

With modern intensive medical therapy, the annual risk of ipsilateral stroke in patients with asymptomatic carotid stenosis (ACS) is now down to ∼0.5%. Despite this, there is a widespread practice of routine intervention in ACS with carotid endarterectomy (CEA) and stenting (CAS). This is being justified on the basis of much higher risks with medical therapy in trials conducted decades ago, compared with lower risks of intervention in recent trials with no medical arm. Such extrapolations are invalid. Although recent trials have shown that after subtracting periprocedural risks the outcomes with CEA and CAS are now comparable to medical therapy, the periprocedural risks still far outweigh the risks with medical therapy. In the asymptomatic carotid trial (ACT) 1 trial, the 30-day risk of stroke or death was 2.9% with CAS and 1.7% with CEA. In the CREST trial, the 30-day risk of stroke or death among asymptomatic patients was 2.5% for stenting and 1.4% for endarterectomy. Thus, intensive medical therapy is much safer than either CAS or CEA. The only patients with ACS who should receive intervention are those who can be identified as being at high risk. The best validated method is transcranial Doppler embolus detection. Other approaches in development for identifying vulnerable plaques include intraplaque haemorrhage on MRI, ulceration and plaque lucency on ultrasound, and plaque inflammation on positron emission tomography/CT. Intensive medical therapy for ACS includes smoking cessation, a Mediterranean diet, effective blood pressure control, antiplatelet therapy, intensive lipid-lowering therapy and treatment with B vitamins (with methylcobalamin instead of cyanocobalamin), particularly in patients with metabolic B12 deficiency. A new strategy called 'treating arteries instead of risk factors', based on measurement of carotid plaque volume, is promising but requires validation in randomised trials.

Management of Patients with an Asymptomatic Carotid Stenosis--Medical Management, Endovascular Treatment, or Carotid Endarterectomy?

Patients with asymptomatic carotid stenosis all warrant intensive medical therapy; they are at a higher risk of myocardial infarction than of stroke. With modern intensive medical therapy, the annual risk of ipsilateral is now ∼ 0.5%. Justifying carotid intervention on the basis of the results of historic trials with a medical arm, extrapolated to modern trials with lower interventional risks but no medical arm is not legitimate. Most patients (∼ 90%) with asymptomatic carotid stenosis would be better served by intensive medical therapy than by either stenting or endarterectomy. The few (∼ 10%) who could benefit from intervention can be identified by microemboli on transcranial Doppler and other methods in development. Routine stenting of asymptomatic carotid stenosis, because it is more likely to harm than help the patient, may be considered unethical.

White Matter Diffusion Abnormalities in Carotid Artery Disease: A Systematic Review and Meta-Analysis

BACKGROUND & PURPOSE

Abnormalities in apparent diffusion coefficient (ADC), fractional anisotropy (FA), and mean diffusivity (MD) values can be used to assess microstructural damage to white matter tracts and could represent a quantitative marker of chronic ischemia and thereby potentially serve as a stroke risk factor or a measure of existing subclinical ischemic disease burden. We performed a systematic review and 3 separate meta-analyses to evaluate the association between unilateral carotid steno-occlusion and ipsilateral ADC, FA, or MD abnormality.

MATERIALS & METHODS

A comprehensive literature search evaluating the association of carotid disease and quantitative white matter diffusion imaging was performed. The included studies examined patients for ADC, FA, and MD values ipsilateral and contralateral to the site of carotid artery disease. Three meta-analyses using standardized mean differences with assessment of study heterogeneity were performed.

RESULTS

Of the 2,920 manuscripts screened, 6 met eligibility for meta-analysis. Of the included manuscripts, 2 studied ADC values, 6 studied FA values, and 2 studied MD values. Our 3 meta-analyses showed standardized mean difference for ADC, FA, and MD values between cerebral hemispheres ipsilateral and contralateral to carotid artery disease site as 1.13 (95% CI: .79-1.47, P < .001), -.42 (95% CI: -.62 to -.21, P < .001), and .23 (95% CI: -.32 to -.77, P = .41), respectively. Measures of heterogeneity showed mild heterogeneity in the 3 meta-analyses.

CONCLUSION

Carotid artery disease is associated with significant ADC and FA value changes, suggesting that carotid disease is associated with quantifiable white matter microstructural damage.

SPACE-2: A Missed Opportunity to Compare Carotid Endarterectomy, Carotid Stenting, and Best Medical Treatment in Patients with Asymptomatic Carotid Stenoses

BACKGROUND

Because of recent advances in best medical treatment (BMT), it is currently unclear whether any additional surgical or endovascular interventions confer additional benefit, in terms of preventing late ipsilateral carotid territory ischemic stroke in asymptomatic patients with significant carotid stenoses. The aim was to compare the stroke-preventive effects of BMT alone, with that of BMT in combination with carotid endarterectomy (CEA) or carotid artery stenting (CAS) in patients with high grade asymptomatic extracranial carotid artery stenosis.

METHODS

SPACE-2 was planned as a three-armed, randomized controlled trial (BMT alone vs. CEA plus BMT vs. CAS plus BMT, ISRCTN 78592017). However, because of slow patient recruitment, the three-arm study design was amended (July 2013) to become two parallel randomized studies (BMT alone vs. CEA plus BMT, and BMT alone vs. CAS plus BMT).

RESULTS

The change in study design did not lead to any significant increase in patient recruitment, and trial recruitment ceased after recruiting 513 patients over a 5 year period (CEA vs. BMT (n = 203); CAS vs. BMT (n = 197), and BMT alone (n = 113)). The 30 day rate of death/stroke was 1.97% for patients undergoing CEA, and 2.54% for patients undergoing CAS. No strokes or deaths occurred in the first 30 days after randomization in patients randomized to BMT. There were several potential reasons for the low recruitment rates into SPACE-2, including the ability for referring doctors to refer their patients directly for CEA or CAS outwith the trial, an inability to convince patients (who had come "mentally prepared" that an intervention was necessary) to accept BMT, and other economic constraints.

CONCLUSIONS

Because of slow recruitment rates, SPACE-2 had to be stopped after randomizing only 513 patients. The German Research Foundation will provide continued funding to enable follow up of all recruited patients, and it is also planned to include these data in any future meta-analysis prepared by the Carotid Stenosis Trialists Collaboration.

Endarterectomy vs. stenting vs. medical therapy

In recent trials, after deducting the risks in the 30-day periprocedural period, the long-term risk of stroke or death was similar with carotid stenting (CAS) and endarterectomy (CEA) for asymptomatic carotid stenosis (ACS) – approximately 0.5% per year. These findings may exacerbate the problem of inappropriate routine intervention in ACS, being justified on the basis of an invalid comparison of the risks in the medical arms of clinical trials conducted decades ago (˜ 2% per year) to the risks in modern trials of CAS vs. CEA with no medical arm. Intervention is regarded as justified if it can be carried out with a risk below 3%. The annual risk of ipsilateral stroke or death in ACS with intensive medical therapy is now ˜ 0.5% – similar to the long-term risk after the periprocedural period in recent trials of intervention. However, periprocedural risk was ˜ 3% for CAS and 1.7% for CEA. Thus with modern CAS and CEA, the risk remains much higher than with modern medical therapy, even with careful vetting of the surgeons and interventionalists. In real world practice, documented in registries, the risks are much higher. National differences – 90% of carotid intervention for ACS in the US vs. 0% in Denmark – bring into question the advisability and ethics of routine intervention. A moratorium on routine intervention for ACS should be respected except in ongoing randomized trials comparing CAS, CEA and modern intensive medical therapy. Patients with high-risk ACS can be identified for appropriate intervention.

Critical Issues That Need to Be Addressed to Improve Outcomes for Patients With Carotid Stenosis

Significant improvement in outcomes for patients with carotid stenosis requires liberation from the historic fixation with randomization and a procedurally based, late-stage, reactive approach to medical care. We require a multipronged and multidisciplinary approach that includes all of the following: (i) removal of overreliance on, and biased use of, randomized trial data; (ii) using accurate ways to rank evidence quality and relevance; (iii) improved research reporting standards; (iv) building quality assurance and other research capability into routine practice; (v) producing evidence-true rather than evidence-based guidelines; (vi) bringing current optimal medical treatment to the community and measuring its effectiveness; (vii) funding only interventions known to help patients when and where they are treated and use the savings to fund vital research, including quality assurance in routine practice; and (viii) recognize that making the indication for carotid procedures obsolete is a good thing.

Ultrasound-Based Carotid Elastography for Detection of Vulnerable Atherosclerotic Plaques Validated by Magnetic Resonance Imaging

Ultrasound-based carotid elastography has been developed to estimate the mechanical properties of atherosclerotic plaques. The objective of this study was to evaluate the in vivo capability of carotid elastography in vulnerable plaque detection using high-resolution magnetic resonance imaging as reference. Ultrasound radiofrequency data of 46 carotid plaques from 29 patients (74 ± 5 y old) were acquired and inter-frame axial strain was estimated with an optical flow method. The maximum value of absolute strain rate for each plaque was derived as an indicator for plaque classification. Magnetic resonance imaging of carotid arteries was performed on the same patients to classify the plaques into stable and vulnerable groups for carotid elastography validation. The maximum value of absolute strain rate was found to be significantly higher in vulnerable plaques (2.15 ± 0.79 s(-1), n = 27) than in stable plaques (1.21 ± 0.37 s(-1), n = 19) (p < 0.0001). Receiver operating characteristic curve analysis was performed, and the area under the curve was 0.848. Therefore, the in vivo capability of carotid elastography to detect vulnerable plaques, validated by magnetic resonance imaging, was proven, revealing the potential of carotid elastography as an important tool in atherosclerosis assessment and stroke prevention.

Management of asymptomatic carotid stenosis

With modern intensive medical therapy, the risk of ipsilateral stroke in patients with asymptomatic carotid stenosis (ACS) is below the risk of either carotid stenting or endarterectomy. Routine intervention for ACS is therefore not justified; approximately 90% of patients with ACS would be better off with intensive medical therapy. The few who could benefit can be identified by transcranial Doppler embolus detection or features of vulnerable plaque that can be imaged by 3-dimensional ultrasound, MRI or positron emission tomography/computed tomography; some of these methods are still in development.

Systematic Review of Guidelines for the Management of Asymptomatic and Symptomatic Carotid Stenosis

BACKGROUND AND PURPOSE

We systematically compared and appraised contemporary guidelines on management of asymptomatic and symptomatic carotid artery stenosis.

METHODS

We systematically searched for guideline recommendations on carotid endarterectomy (CEA) or carotid angioplasty/stenting (CAS) published in any language between January 1, 2008, and January 28, 2015. Only the latest guideline per writing group was selected. Each guideline was analyzed independently by 2 to 6 authors to determine clinical scenarios covered, recommendations given, and scientific evidence used.

RESULTS

Thirty-four eligible guidelines were identified from 23 different regions/countries in 6 languages. Of 28 guidelines with asymptomatic carotid artery stenosis procedural recommendations, 24 (86%) endorsed CEA (recommended it should or may be provided) for ≈50% to 99% average-surgical-risk asymptomatic carotid artery stenosis, 17 (61%) endorsed CAS, 8 (29%) opposed CAS, and 1 (4%) endorsed medical treatment alone. For asymptomatic carotid artery stenosis patients considered high-CEA-risk because of comorbidities, vascular anatomy, or undefined reasons, CAS was endorsed in 13 guidelines (46%). Thirty-one of 33 guidelines (94%) with symptomatic carotid artery stenosis procedural recommendations endorsed CEA for patients with ≈50% to 99% average-CEA-risk symptomatic carotid artery stenosis, 19 (58%) endorsed CAS and 9 (27%) opposed CAS. For high-CEA-risk symptomatic carotid artery stenosis because of comorbidities, vascular anatomy, or undefined reasons, CAS was endorsed in 27 guidelines (82%). Guideline procedural recommendations were based only on results of trials in which patients were randomized 12 to 34 years ago, rarely reflected medical treatment improvements and often understated potential CAS hazards. Qualifying terminology summarizing recommendations or evidence lacked standardization, impeding guideline interpretation, and comparison.

CONCLUSIONS

This systematic review has identified many opportunities to modernize and otherwise improve carotid stenosis management guidelines.

Preoperative Coronary Stenosis Is a Determinant of Early Vascular Outcome after Carotid Endarterectomy

BACKGROUND AND PURPOSE

The benefit of carotid endarterectomy (CEA) is directly influenced by the risk of perioperative adverse outcomes. However, patient-level risks and predictors including coronary stenosis are rarely evaluated, especially in Asian patients. The aim of this study was to determine the relationship between the vascular risk factors underlying CEA, including coronary stenosis, and postoperative outcome.

METHODS

One hundred and fifty-three consecutive CEAs from our hospital records were included in this analysis. All patients underwent coronary computed tomography angiography before CEA. Data were analyzed to determine the vascular outcomes in patients with mild-to-moderate vs. severe coronary stenosis and high vs. standard operative risk, based on the criteria for high operative risk defined in the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial. The vascular outcome was defined as the occurrence of postoperative (≤30 days) stroke, myocardial infarction (MI), or death.

RESULTS

An adverse vascular outcome occurred in 8 of the 153 CEAs, with 6 strokes, 2 MIs, and 3 deaths. The vascular outcome differed significantly between the groups with mild-to-moderate and severe coronary stenosis (p=0.024), but not between the high- and standard-operative-risk groups (stratified according to operative risk as defined in the SAPPHIRE trial). Multivariable analysis adjusting for potent predictors revealed that severe coronary stenosis (odds ratio, 6.87; 95% confidence interval, 1.20-39.22) was a significant predictor of the early vascular outcome.

CONCLUSIONS

Severe coronary stenosis was identified herein as an independent predictor of an adverse early vascular outcome.

Preoperative optimization of the vascular surgery patient

It is well known that patients who suffer from peripheral (noncardiac) vascular disease often have coexisting atherosclerotic diseases of the heart. This may leave the patients susceptible to major adverse cardiac events, including death, myocardial infarction, unstable angina, and pulmonary edema, during the perioperative time period, in addition to the many other complications they may sustain as they undergo vascular surgery procedures, regardless of whether the procedure is performed as an open or endovascular modality. As these patients are at particularly high risk, up to 16% in published studies, for postoperative cardiac complications, many proposals and algorithms for perioperative optimization have been suggested and studied in the literature. Moreover, in patients with recent coronary stents, the risk of non-cardiac surgery on adverse cardiac events is incremental in the first 6 months following stent implantation. Just as postoperative management of patients is vital to the outcome of a patient, preoperative assessment and optimization may reduce, and possibly completely alleviate, the risks of major postoperative complications, as well as assist in the decision-making process regarding the appropriate surgical and anesthetic management. This review article addresses several tools and therapies that treating physicians may employ to medically optimize a patient before they undergo noncardiac vascular surgery.

Bias in the use of randomized trials for carotid stenosis management

Background

Carotid artery procedures, such as surgery and stenting, although associated with significant risks and costs, are often recommended in guidelines which cite12- to 34-year-old randomized trial evidence of benefit; however, these recommendations exist although there is no evidence these procedures benefit patients who receive only current optimal medical treatment  (encouragement of a healthy lifestyle and appropriate use of medication).

Objective

To examine whether bias exists in the use of randomized trial evidence and its impact on guideline recommendations.

Material and methods

Examples of how bias underpins endorsement of carotid procedures for patients with asymptomatic or symptomatic carotid stenosis were sought from available literature. .

Results

Many forms of procedural bias were identified involving the need for randomized trials, and their design and interpretation. Fundamental problems included failure to first adequately measure outcomes with non-invasive treatment alone, lack of appreciation of quality non-randomized trial measurements of risk in determining need for randomized trials and their applicability in routine practice, poor randomized trial methods with biased comparisons, inaccurate definitions of target populations, confusion of efficacy and safety outcomes, too much reliance on statistical rather than clinical significance and biased use of terminology to make procedures sound more effective.

Conclusion

Procedural bias in design and interpretation of randomized trials has resulted in widespread loss of understanding of how to optimize outcomes in patients with carotid artery stenosis. Current guidelines reflect the cumulative impact of this bias and are an excellent starting point for efforts to improve prevention of stroke and other vascular disease complications; however, there is also need for clinicians, policy makers, health service funding bodies, educators and the general public to assist.

Carotid Plaque Morphological Classification Compared With Biomechanical Cap Stress: Implications for a Magnetic Resonance Imaging-Based Assessment

BACKGROUND AND PURPOSE

Two approaches to target plaque vulnerability-a histopathologic classification scheme and a biomechanical analysis-were compared and the implications for noninvasive risk stratification of carotid plaques using magnetic resonance imaging were assessed.

METHODS

Seventy-five histological plaque cross sections were obtained from carotid endarterectomy specimens from 34 patients (>70% stenosis) and subjected to both a Virmani histopathologic classification (thin fibrous cap atheroma with <0.2-mm cap thickness, presumed vulnerable) and a peak cap stress computation (<140 kPa: presumed stable; >300 kPa: presumed vulnerable). To demonstrate the implications for noninvasive plaque assessment, numeric simulations of a typical carotid magnetic resonance imaging protocol were performed (0.62×0.62 mm(2) in-plane acquired voxel size) and used to obtain the magnetic resonance imaging-based peak cap stress.

RESULTS

Peak cap stress was generally associated with histological classification. However, only 16 of 25 plaque cross sections could be labeled as high-risk (peak cap stress>300 kPa and classified as a thin fibrous cap atheroma). Twenty-eight of 50 plaque cross sections could be labeled as low-risk (a peak cap stress<140 kPa and not a thin fibrous cap atheroma), leading to a κ=0.39. 31 plaques (41%) had a disagreement between both classifications. Because of the limited magnetic resonance imaging voxel size with regard to cap thickness, a noninvasive identification of only a group of low-risk, thick-cap plaques was reliable.

CONCLUSIONS

Instead of trying to target only vulnerable plaques, a more reliable noninvasive identification of a select group of stable plaques with a thick cap and low stress might be a more fruitful approach to start reducing surgical interventions on carotid plaques.

Moving beyond luminal stenosis: imaging strategies for stroke prevention in asymptomatic carotid stenosis

BACKGROUND

With progressive improvements in medical therapy and resultant reductions in stroke risk, luminal stenosis criteria are no longer adequate to inform decisions to pursue surgical revascularization in patients with asymptomatic carotid artery stenosis.

SUMMARY

In this evidence-based review, we discuss the imaging-based risk stratification strategies that take into account factors beyond luminal stenosis measurements, including cerebral hemodynamics and plaque composition. The existing literature lends support to the use of certain imaging tests in patients with asymptomatic carotid stenosis including cerebrovascular reserve testing, MRI of plaque composition, ultrasound of plaque echolucency, and transcranial Doppler evaluation for microemboli. The highest quality evidence thus far in the literature includes only systematic reviews and meta-analyses of cohort studies with no randomized trials having yet been performed to show how these newer imaging biomarkers could be used to inform treatment decisions in asymptomatic carotid stenosis. Beyond the need for randomized trials, there are additional important steps needed to improve the relevance of evidence supporting risk assessment strategies. Imaging studies evaluating the risk of stroke in carotid disease should clearly define asymptomatic versus symptomatic disease, use uniform definitions of clearly defined outcome measures such as ipsilateral stroke, ensure that imaging interpretations are performed in a manner blinded to treatments and other risk factors, and include cohorts which are on modern intensive medical therapy. Such studies of risk stratification for asymptomatic carotid stenosis will be most valuable if they can integrate multiple high-risk features (including clinical risk factors) into a multi-factorial risk assessment strategy in a manner that is relatively simple to implement and generalizable across a wide range of practice settings. Key Messages: Together, modern imaging strategies allow for a more mechanistic assessment of stroke risk in carotid disease compared to luminal stenosis measurements alone, which, with further validation in randomized controlled trials, may improve current efforts at stroke prevention in asymptomatic carotid stenosis.

Surgeon case volume and 30-day mortality after carotid endarterectomy among contemporary medicare beneficiaries: before and after national coverage determination for carotid artery stenting

BACKGROUND AND PURPOSE

After the 2005 National Coverage Determination to reimburse carotid artery stenting (CAS) for Medicare beneficiaries, the number of CAS procedures increased and carotid endarterectomy (CEA) decreased. We evaluated trends in surgeons' past-year CEA case-volume and 30-day mortality after CEA, and their association before and after the National Coverage Determination.

METHODS

In a retrospective cohort study of patients undergoing CEA (2001-2008) and CAS (2005-2008) using Medicare data, we described yearly trends of CEA and CAS rates, patient characteristics, and 30-day mortality after CEA. We used logistic regression adjusting for patient- and surgeon-level factors to assess the effect of surgeon case volume on 30-day mortality after CEA.

RESULTS

We identified 454 717 CEA and 27 943 CAS patients. Patients undergoing CEA in recent years were older and had more comorbidities than earlier years. CEA rates per 10 000 beneficiaries declined from 18.1 in 2002 to 12.7 in 2008, whereas median surgeon past-year case-volume declined from 27 to 21. The CAS rates peaked at 2.3 per 10 000 beneficiaries in 2006 but declined to 1.8 in 2008, resulting in declining overall revascularization procedure rates during 2005 to 2008. Thirty day post-CEA mortality was 1.40% (95% confidence interval, 1.34-1.47) in 2001 to 2002 and 1.17% (1.10-1.24) in 2007 to 2008. Surgeon's past-year case-volume of <10 was associated with higher 30-day mortality consistently during 2001 to 2008.

CONCLUSIONS

The rate of CEA procedures decreased substantially during 2001 to 2008, as did surgeon past-year case-volume. The postprocedural mortality in Medicare beneficiaries was high compared with trial patients but somewhat improved over time. Those operated by lower past-year case-volume surgeons had increased mortality.

[A role of carotid endarterectomy in prevention of cerebral ischemic damage]

Authors present a literature review on the prevalence, clinical presentations, diagnosis and outcome of surgical treatment of atherosclerotic stenosis of the internal carotid artery.

Why is the management of asymptomatic carotid disease so controversial?

BACKGROUND

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

METHODS

Review of current strategies for managing asymptomatic carotid disease

MAIN FINDINGS

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

CONCLUSIONS

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

Perioperative management of combined carotid and coronary artery bypass grafting procedures

The objective of this review is to provide a high level overview on current thinking for treatment of patients with combined carotid and coronary artery disease given that these patients are at higher risk of adverse cardiac events, stroke, and death. This review discusses (1) the current literature addressing perioperative stroke risk in the setting of coronary artery bypass graft, (2) the literature regarding different surgical approaches when both carotid and coronary revascularization are being considered, and (3) the data available to guide optimal management of this complex patient population to minimize complications regardless of the surgical approach taken.

William Hunter Harridge Lecture. Carotid endarterectomy versus stenting for stroke prevention: what we have and will learn from Carotid Revascularization Endarterectomy versus Stenting Trial

The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) has major implications for the future of carotid revascularization and stroke prevention. The purpose of The William Hinter Harridge Lecture was to discuss the history of carotid revascularization before CREST, to delineate the emergence of carotid artery stenting as an alternative to carotid endarterectomy, analyze the key findings in CREST, and describe the next phase of investigation, CREST-2.