Extracranial carotid artery stenosis

Utility of the triglyceride-glucose index for predicting restenosis following revascularization surgery for extracranial carotid artery stenosis: A retrospective cohort study

BACKGROUND

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are effective interventions for treating extracranial carotid artery stenosis (ECAS), but long-term prognosis is limited by postoperative restenosis. Carotid restenosis is defined as carotid stenosis >50% by various examination methods in patients after carotid revascularization. This retrospective cohort study examined the value of the triglyceride-glucose (TyG) index for predicting vascular restenosis after carotid revascularization.

METHODS

A total of 830 patients receiving CEA (408 cases, 49.2%) or CAS (422 cases, 50.8%) were included in this study. Patients were stratified into three subgroups according to TyG index tertile (high, intermediate, and low), and predictive value for restenosis was evaluated by constructing multivariate Cox proportional hazard regression models.

RESULTS

Incidence of postoperative restenosis was significantly greater among patients with a high TyG index according to univariate analysis. Kaplan-Meier survival curve analysis revealed a progressive increase in restenosis prevalence with rising TyG index. Multivariate Cox regression models also identified TyG index as an independent predictor of restenosis, while receiver operating characteristic (ROC) curve analysis showed that TyG index predicted restenosis with moderate sensitivity (57.24%) and specificity (67.99%) (AUC: 0.619, 95% CI 0.585-0.652, z-statistic=4.745, p<0.001). Addition of the TyG index to an established risk factor model incrementally improved restenosis prediction (AUC: 0.684 (0.651-0.715) vs 0.661 (0.628-0.694), z-statistic =2.027, p = 0.043) with statistical differences.

CONCLUSION

The TyG index is positively correlated with vascular restenosis risk after revascularization, which can be used for incremental prediction and has certain predictive value.

Contralateral Carotid Stenosis is a Predictor of Long-term Adverse Events in Carotid Endarterectomy

Contralateral carotid stenosis (clCS) has been described as a perioperative predictor of mortality after carotid endarterectomy (CEA). However, its predictive value on long-term cardiovascular events remains controversial. The study aims to assess the potential role of clCS as a long-term predictor of major adverse cardiovascular events (MACE) in patients who underwent CEA. From January 2012 to July 2020, patients undergoing CEA under regional anesthesia for carotid stenosis in a tertiary care and referral center were eligible from a prospective database, and a post hoc analysis was performed. The primary outcome consisted in the occurrence of long-term MACE. Secondary outcomes included all-cause mortality, stroke, myocardial infarction, acute heart failure, and major adverse limb events. A total of 192 patients were enrolled. With a median 50 months follow-up, chronic kidney disease (CKD) (mean survival time (MST) 51.7 vs. 103.3, p<0.010) and peripheral artery disease (PAD) (MST 75.1 vs. 90.3, p=0.001) were associated with decreased survival time. After propensity score matching (PSM), CKD (MST 49.1 vs. 106.0, p=0.001) and PAD (MST 75.7 vs. 94.0, p=0.001) maintained this association. On multivariate Cox regression analysis, contralateral stenosis was associated with higher MACE (hazard ratio (HR) = 2.035; 95% CI: 1.113-3.722, p=0.021 and all-cause mortality (HR = 2.564; 95% CI: 1.276-5,152 p=0.008). After PSM, only all-cause mortality (HR 2.323; 95% CI: 0.993-5.431, p=0.052) maintained a significant association with clCS. On multivariable analysis, clCS (aHR 2.367; 95% CI: 1.174-4.771, p=0.016), age (aHR 1.039, 95% CI: 1.008-1.070), CKD (aHR 2.803; 95% CI: 1.409-5.575, p=0.003) and PAD (aHR 3.225, 95% CI: 1.695-6.137, p<0.001) were independently associated with increased all-cause mortality. Contrary to MACE, clCS is a strong predictor of long-term all-cause mortality after CEA. However, MACE risk may compromise CEA benefits by other competitive events. Therefore, further studies are needed to establish the role of clCS on postoperative events and on patients' specific assessments in order to determine the best medical treatment and easy access to surgical intervention.

Geometric determinants of local hemodynamics in severe carotid artery stenosis

In cases of severe carotid artery stenosis (CAS), carotid endarterectomy (CEA) is performed to recover lumen patency and alleviate stroke risk. Under current guidelines, the decision to surgically intervene relies primarily on the percent loss of native arterial lumen diameter within the stenotic region (i.e. the degree of stenosis). An underlying premise is that the degree of stenosis modulates flow-induced wall shear stress elevations at the lesion site, and thus indicates plaque rupture potential and stroke risk. Here, we conduct a retrospective study on pre-CEA computed tomography angiography (CTA) images from 50 patients with severe internal CAS (>60% stenosis) to better understand the influence of plaque and local vessel geometry on local hemodynamics, with geometrical descriptors that extend beyond the degree of stenosis. We first processed CTA images to define a set of multipoint geometric metrics characterizing the stenosed region, and next performed computational fluid dynamics simulations to quantify local wall shear stress and associated hemodynamic metrics. Correlation and regression analyses were used to relate obtained geometric and hemodynamic metrics, with inclusion of patient sub-classification based on the degree of stenosis. Our results suggest that in the context of severe CAS, prediction of shear stress-based metrics can be enhanced by consideration of readily available, multipoint geometric metrics in addition to the degree of stenosis.

In vitro shear stress measurements using particle image velocimetry in a family of carotid artery models: effect of stenosis severity, plaque eccentricity, and ulceration

Atherosclerotic disease, and the subsequent complications of thrombosis and plaque rupture, has been associated with local shear stress. In the diseased carotid artery, local variations in shear stress are induced by various geometrical features of the stenotic plaque. Greater stenosis severity, plaque eccentricity (symmetry) and plaque ulceration have been associated with increased risk of cerebrovascular events based on clinical trial studies. Using particle image velocimetry, the levels and patterns of shear stress (derived from both laminar and turbulent phases) were studied for a family of eight matched-geometry models incorporating independently varied plaque features - i.e. stenosis severity up to 70%, one of two forms of plaque eccentricity, and the presence of plaque ulceration). The level of laminar (ensemble-averaged) shear stress increased with increasing stenosis severity resulting in 2-16 Pa for free shear stress (FSS) and approximately double (4-36 Pa) for wall shear stress (WSS). Independent of stenosis severity, marked differences were found in the distribution and extent of shear stress between the concentric and eccentric plaque formations. The maximum WSS, found at the apex of the stenosis, decayed significantly steeper along the outer wall of an eccentric model compared to the concentric counterpart, with a 70% eccentric stenosis having 249% steeper decay coinciding with the large outer-wall recirculation zone. The presence of ulceration (in a 50% eccentric plaque) resulted in both elevated FSS and WSS levels that were sustained longer (∼20 ms) through the systolic phase compared to the non-ulcerated counterpart model, among other notable differences. Reynolds (turbulent) shear stress, elevated around the point of distal jet detachment, became prominent during the systolic deceleration phase and was widely distributed over the large recirculation zone in the eccentric stenoses.

Extracranial internal carotid arterial disease in children with sickle cell anemia

BACKGROUND

Sickle cell anemia is one of the commonest causes of stroke in children. It is usually, but not always, associated with intracranial vasculopathy. We have assessed the value of ultrasound screening for extracranial internal carotid artery disease.

DESIGN AND METHODS

Using Doppler ultrasound scanning, we assessed peak systolic blood velocity, tortuosity and stenosis in the extracranial internal carotid arteries of 236 children with sickle cell anemia. Seventeen of the children had previously had a stroke. All measurements were performed as part of routine clinical care.

RESULTS

The median extracranial internal carotid artery velocity was 148cm/s (5(th) centile 84, 95(th) centile 236). Higher velocities were significantly correlated with younger age, higher white blood cell counts and higher rates of hemolysis. Fourteen (5.9%) had tortuous extracranial internal carotid arteries and 13 (5.4%) had stenosis or occlusion. None of the children with tortuous vessels but 8 of those with stenosis had previously had a stroke; the presence of stenosis was strongly associated with overt clinical stroke (OR 35.9, 95% C.I. 9.77-132, P<0.001). In 6 children, extracranial stenosis was part of extensive intracranial vasculopathy, but in 2 there was no evidence of intracranial disease. Stenosis seemed to be more common in older children.

CONCLUSIONS

Extracranial internal carotid artery stenosis is strongly associated with stroke in children with sickle cell anemia, and may explain some cases of stroke without overt intracranial vasculopathy. Doppler ultrasound scanning of extracranial internal carotid arteries is non-invasive and fairly quick to perform and may identify children at increased risk of stroke who would otherwise be missed. The value of extracranial internal carotid artery scanning should be studied prospectively.

A three-dimensional ultrasonographic quantitative analysis of non-ulcerated carotid plaque morphology in symptomatic and asymptomatic carotid stenosis

BACKGROUND AND PURPOSE

Studies evaluating the association between carotid plaque composition and occurrence of ischemic cerebrovascular disease reveal inconsistent results. This study correlates the carotid echomorphology with the degree of stenosis in symptomatic and asymptomatic patients.

METHODS

We included consecutive patients with hemispheric stroke or asymptomatic carotid artery stenosis assessed with 2D ultrasound. The echomorphology was assessed with mean gray value (MGV) of the three-dimensional (3D) volume. We used the free-hand approach for 3D image and volume acquisition. Analyses of the stored carotid plaque volumes were carried out offline using the Virtual Organ Computer-aided Analysis (VOCAL) program.

RESULTS

We studied 110 symptomatic and 104 asymptomatic atherosclerotic carotid plaques. MGV was lower in symptomatic carotid plaques causing <70% stenosis compared to plaques causing > or =70% stenosis (25.95+/-7.40 vs. 32.16+/-11.35, p=0.002). There was no difference in MGV between plaques producing <60% and those with > or =60% in asymptomatic patients (32.08+/-8.36 vs. 31.46+/-9.25, p=0.724). There were significant differences in MGV between symptomatic and asymptomatic plaques causing <60 or <70% stenosis; MGV was lower in symptomatic patients.

CONCLUSIONS

Lower plaque echogenicity is observed in symptomatic than in asymptomatic patients with moderate degree of carotid stenosis, indicating that it is a significant factor for the production of cerebral ischemia. Our method could be useful in assessing the risk of cerebral ischemia and the response of carotid artery atherosclerosis to medical therapies.

Experience of 500 cases of neurophysiological monitoring in carotid endarterectomy

BACKGROUND

Experience with Intraoperative monitoring using neurophysiological and haemodynamic indices in 500 operations for carotid endarterectomy is reported.

METHODS

Transcranial Doppler technique (TCD), electroencephalogram (EEG) and bilateral median somatosensory evoked potentials (SEP) were performed. Latency and amplitude of SEP, spectral analysis of EEG signal and blood flow velocity in the medial cerebral artery (MCA) were continuously measured.

FINDINGS

After two consecutive drops of N20/P25 complex of more than 50%, a warning was given, and when the decrease continued, an the alarm raised. Abnormal EEG changes, if any, appeared after a significant decrease in the N20/P25 amplitude. A mean blood flow velocity drop below 40% of the reference value after cross clamping was rated as a significant warning event.A warning as a result of a decrease in N20/P25 amplitude occurred in 80 operations (16.0%), after an spectral edge frequency decrease in 2 cases (0.4%) and after a V(mean) decrease in 21 cases (4.2%). False negative results were experienced in 2 patients (0.4%). A shunt was inserted in 2.8% of the operations. The overall mortality/morbidity rate was 2.4%.

CONCLUSION

A decrease of more than 50% in the amplitude of the thalamocortical somatosensory evoked potential complex N20/P25 proved to be the most reliable warning of danger of ischaemia during carotid endarterectomy.

Association Between Disability Measures and Healthcare Costs After Initial Treatment for Acute Stroke

BACKGROUND AND PURPOSE

The distribution of 3-month modified Rankin scale (mRS) scores has been used as an outcome measure in acute stroke trials. We hypothesized that hospitalization and institutional care home stays within the first 90 days after stroke should be closely related to 90-day mRS, that each higher mRS category will reflect incremental cost, and that resource use may be less clearly linked to the National Institutes of Health Stroke Scale (NIHSS) or Barthel index.

METHODS

We examined resource use data from the GAIN International trial comparing 90-day mRS with total length of stay in hospital or other institutions during the first 90 days. We repeated analyses using NIHSS and Barthel index scores. Relationships were examined by analysis of variance (ANOVA) with Bonferroni contrasts of adjacent score categories. Estimated costs were based on published Scottish figures.

RESULTS

We had full data from 1717 patients. Length of stay was strongly associated with final mRS (P<0.0001). Each mRS increment from 0 to 1-2 to 3-4 was significant (mean length of stay: 17, 25, 44, 58, 79 days; P<0.0005). Ninety-five percent confidence limits for estimated costs ( pound) rose incrementally: 2493 to 3412, 3369 to 4479, 5784 to 7008, 7300 to 8512, 10 095 to 11 141, 11 772 to 13 560, and 2623 to 3321 for mRS 0 to 5 and dead, respectively. Weaker relationships existed with Barthel and NIHSS.

CONCLUSIONS

Each mRS category reflects different average length of hospital and institutional stay. Associated costs are meaningfully different across the full range of mRS outcomes. Analysis of the full distribution of mRS scores is appropriate for interpretation of treatment effects after acute stroke and more informative than Barthel or NIHSS end points.

[Carotid stenosis: appropriate diagnosis and treatment]

Ischemic cerebral infarcts represent a serious health problem with important social and economic repercussions in the western world. The presence of carotid stenosis is one of the main risk factors for the appearance of cerebral infarcts. Carotid stenosis represents a challenge for the medical community, both because of the enormous amount of scientific information available and because of the constant advances in diagnostic procedures and especially in revascularization techniques for treatment. General radiologists as well as those specializing in vascular pathology need to have ample knowledge of how to reach the diagnosis and of the different treatment options for this pathology if they are to play a successful role in multidisciplinary teams dealing with carotid stenosis. This update aims to present the basic information that we consider to be essential in a simple way to enable radiologists to meet this challenge.

Distal protection in cardiovascular medicine: current status

Iatrogenic and spontaneous downstream microembolization of atheromatous material is increasingly recognized as a source of cardiovascular morbidity and mortality. Devising ways of reducing this distal embolization using a variety of mechanical means--distal protection--is currently under intense and diverse investigation. This review therefore summarizes the present status of distal protection. It examines the problem of distal embolization, describes the available distal protection devices, reviews those areas of cardiovascular medicine where distal protection devices are being investigated, and discusses potential future developments.

Coronary angiography in patients undergoing carotid artery stenting shows a high incidence of significant coronary artery disease

OBJECTIVE

To assess the incidence, morphology, and associated clinical symptoms of coronary artery disease in patients undergoing elective carotid artery stenting.

METHODS

In a prospective observational study at a tertiary care centre (university teaching hospital) 444 consecutive patients underwent elective stenting of the carotid artery. Twenty four patients had to be ruled out because of urgent carotid intervention for severe neurological symptoms, lack of compliance, complications from vascular puncture, or renal failure. In 390 patients, the coronary angiography was performed together with carotid artery stenting in a single session; the remaining 30 patients have had a recent coronary angiography.

RESULTS

One, two, and three vessel disease and left main stenoses were found in 70 (17%), 64 (15%), 93 (22%), and 31 (7%) patients, respectively. Sixty six (16%) patients had a history of coronary artery disease but no current significant stenosis. Only 39% of the patients with significant stenoses (n = 258) had clinical cardiac symptoms.

CONCLUSIONS

For patients undergoing elective stenting of the carotid, routine coronary angiography reliably discloses morphologically significant coronary artery disease and enables consecutive treatment in 61% and 29%. This safe measure is useful because a majority of patients with a significant stenosis are asymptomatic.

Carotid revascularization for prevention of stroke: carotid endarterectomy and carotid artery stenting

Carotid endarterectomy (CEA) has been used for the past several decades in patients with carotid occlusive disease. Large randomized controlled trials have documented that CEA is a highly effective stroke preventive among patients with carotid stenosis and recent transient ischemic attack or cerebral infarction. In asymptomatic patients with carotid stenosis, clinical trial data suggest that the degree of stroke prevention from CEA is less than among symptomatic patients. However, otherwise healthy men and women with an asymptomatic carotid stenosis of 60% or greater have a lower risk of future cerebral infarction, including disabling cerebral infarction, if treated with CEA compared with those treated with medical management alone. More recently, carotid artery stenting has been performed Increasingly for patients with carotid occlusive disease. As technology has improved, procedural risks have declined and are approaching those reported for CEA. The benefits and durability of CEA compared with carotid artery stenting are still unclear and are being studied in ongoing randomized controlled trials.

Carotid Plaque Echolucency Increases the Risk of Stroke in Carotid Stenting

Background— Carotid artery stenting (CAS) has recently emerged as a potential alternative to carotid endarterectomy. Cerebral embolization is the most devastating complication of CAS, and the echogenicity of carotid plaque has been indicated as one of the risk factors involved. This is the first study to analyze the role of a computer-assisted highly reproducible index of echogenicity, namely the gray-scale median (GSM), on the risk of stroke during CAS.

Methods and Results— The Imaging in Carotid Angioplasty and Risk of Stroke (ICAROS) registry included 418 cases of CAS collected from 11 international centers. An echographic evaluation of carotid plaque with GSM measurement was made preprocedurally. The onset of neurological deficits during the procedure and the postprocedural period was recorded. The overall rate of neurological complications was 3.6%: minor strokes, 2.2%, and major stroke, 1.4%. There were 11 of 155 strokes (7.1%) in patients with GSM ≤25 and 4 of 263 (1.5%) in patients with GSM >25 ( P =0.005). Patients with severe stenosis (≥85%) had a higher rate of stroke ( P =0.03). The effectiveness of brain protection devices was confirmed in those with GSM >25 ( P =0.01) but not in those with GSM ≤25. Multivariate analysis revealed that GSM (OR, 7.11; P =0.002) and rate of stenosis (OR, 5.76; P =0.010) are independent predictors of stroke.

Conclusions— Carotid plaque echolucency, as measured by GSM ≤25, increases the risk of stroke in CAS. The inclusion of echolucency measured as GSM in the planning of any endovascular procedure of carotid lesions allows stratification of patients at different risks of complications in CAS.

Left or right carotid endarterectomy in patients with atherosclerotic disease: Ipsilateral effects on cognition?

We evaluated hemispheric functions ipsilateral to the side of carotid endarterectomy (CEA) in patients with a severe stenosis in the left or right carotid artery. Assessments took place 1 day before and 3 months after CEA. Only right-handed males were included. Nineteen patients underwent surgery of the left carotid artery and 17 of the right. Valid instruments for hemispheric function were included, such as verbal dichotic listening, finger tapping, and a lateralised test for motor planning. Results showed that, preoperatively, patients had lower scores compared to norms on the laterality tests, and on a visuoconstructive test. There was no evidence of ipsilateral improvement related to side of surgery. Left ear dichotic listening improved, which was seen in both left and right surgery groups. Also in both groups, left- and right-hand movement speed in the motor planning test decreased. Conclusion is that beneficial ipsilateral cognitive change after CEA in patients with severe stenosis in one of the carotid arteries may not be demonstrated, even if valid instruments for hemispheric function are included.