Gender differences in blood velocities across carotid stenoses

Bias in artificial intelligence in vascular surgery

Application of artificial intelligence (AI) has revolutionized the utilization of big data, especially in patient care. The potential of deep learning models to learn without a priori assumption, or without prior learning, to connect seemingly unrelated information mixes excitement alongside hesitation to fully understand AI's limitations. Bias, ranging from data collection and input to algorithm development to finally human review of algorithm output affects AI's application to clinical patient presents unique challenges that differ significantly from biases in traditional analyses. Algorithm fairness, a new field of research within AI, aims to mitigate bias by evaluating the data at the preprocessing stage, optimizing during algorithm development, and evaluating algorithm output at the postprocessing stage. As the field continues to develop, being cognizant of the inherent biases and limitations related to black box decision making, biased data sets agnostic to patient-level disparities, wide variation of present methodologies, and lack of common reporting standards will require ongoing research to provide transparency to AI and its applications.

Accuracy of the Society of Radiologists in Ultrasound (SRU) Carotid Doppler Velocity Criteria for Grading North American Symptomatic Carotid Endarterectomy Trial (NASCET) Stenosis: A Meta-Analysis

PURPOSE

The Society of Radiologists in Ultrasound (SRU) consensus panel proposed six Doppler velocity cut points for classifying internal carotid artery (ICA) stenosis of 50% and 70% according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method. Their relative accuracies have not been compared.

MATERIALS AND METHODS

Meta-analysis performed following comprehensive literature review and identification of manuscripts with graphs of individual patient NASCET ICA stenosis measured by arteriography versus ICA peak-systolic velocity (PSV), end-diastolic velocity (EDV) and ICA PSV to common carotid artery (CCA) PSV. True positives, true negatives, false positives, and false negatives were calculated and used in two-level mixed effects models. Hierarchical summary receiver operating characteristic (ROC) curves were generated. Areas under the ROC curves were estimated.

RESULTS

Nine studies performed between 1993 and 2016 were identified after review of 337 manuscripts. There were 1738 bifurcation data points extracted for PSV, 1026 for EDV, and 775 for ICA/CCA ratio. The highest sensitivity was 96% (95% CI: 93%, 98%) for PSV of 125 cm/s (50% stenosis) and highest specificity 86% (95% CI: 71%, 93%) for PSV of 230 cm/s (70% stenosis). Areas under the ROC curves ranged from a high of 0.93 (95% CI: 0.92, 0.95) for PSV (50% stenosis) to a low of 0.86 (95% CI: 0.84, 0.88) for EDV (70% stenosis).

CONCLUSIONS

The SRU consensus Doppler cut points vary in their accuracies for predicting ICA stenosis. The PSV cut points have tradeoffs: high sensitivity/low specificity for 50% stenosis and high specificity/moderate sensitivity for 70% stenosis.

Performance of Carotid Revascularization Procedures as Modified by Sex

BACKGROUND

Current recommendations on carotid revascularization postulate that women have both increased perioperative risks, such as stroke and death, as well as reduced benefit from intervention. These recommendations do not include data on transcarotid artery revascularization (TCAR). This study strives to compare safety and benefits of TCAR, TFCAS (Transfemoral Carotid Artery Stenting), and CEA (Carotid Endarterectomy) with regard to patient sex.

METHODS

We performed retrospective analysis of the Society for Vascular Surgery (SVS) Vascular Quality Initiative (VQI) CEA and stenting registries, as well as TCAR Surveillance Project data. We compared outcomes after TCAR, TFCAS, and CEA based on sex. The primary outcome was the rate of in-hospital stroke or death. Secondary outcomes included in-hospital stroke, death, transient ischemic attack (TIA), myocardial infarction (MI), stroke/death/MI, stroke/TIA, and recurrent ipsilateral stroke and/or death at 1-year of follow-up.

RESULTS

 A total of 75,538 patients were included, of which 28,960 (38.3%) were female and 46,578 (61.7%) were male. TFCAS females had more than 2 times higher odds of stroke/death (OR:2.85, 95%CI: 2.21-3.67, P < 0.001) and stroke/death/MI (OR:2.23, 95%CI:1.75-2.83, P < 0.001) when compared to CEA females. Odds of TIA were also higher in both TFCAS females (OR:2.01, 95%CI:1.19-3.42, P = 0.010) and TCAR females (OR:1.91, 95%CI:1.09-3.35, P = .023) when compared to CEA females. However, only TFCAS females experienced increased odds of stroke/TIA (OR:1.96, 95%CI:1.45-2.65, P < 0.001) when compared to CEA females. TFCAS males had almost twice the odds of stroke/death (OR:1.74, 95%CI:1.39-2.16, P < 0.001) and 44% higher odds of stroke/death/MI (OR:1.44, 95%CI:1.19-1.75, P < 0.001), and more than 3-times increased odds of death (OR:3.45, 95%CI:2.53-4.71, P < 0.001) when compared to CEA males. Odds of in-hospital stroke were comparable between TFCAS and CEA after adjusting for covariates. TCAR males have half the odds of MI when compared to CEA males (OR:0.52, 95%CI:0.34-0.80, P = 0.003). At 1-year TCAR had comparable risk of stroke/death while TFCAS had increased risk of stroke/death when compared to CEA among both males and females.

CONCLUSION

TCAR performed similarly to CEA in both sexes regardless of symptomatic status. Stroke/death and stroke/death/MI rates were similar in symptomatic and asymptomatic males and females treated by CEA or TCAR. The 1-year outcomes of TCAR were also comparable to CEA in both sexes. It seems that TCAR may be a safe alternative to CEA particularly in women when surgical risk prohibits CEA and while TFCAS is associated with substantial adverse outcomes.

Differential association of flow velocities in the carotid artery with plaques, intima media thickness and cardiac function

Background and aims

We aimed to determine the association of carotid intima media thickness (CIMT), carotid plaques, and heart function with peak systolic velocity (PSV) of the common (CCA) and internal carotid artery (ICA) in a cross-sectional study.

Methods

In the population-based Hamburg-City-Health-Study participants between 45 and 74 years were recruited. Cardio-vascular risk factors were assessed by history, blood samples, and clinical examination. CIMT, plaques, and PSV were determined by carotid ultrasound. Serum N-terminal brain natriuretic peptide (NT-proBNP) was determined as a biomarker for cardiac dysfunction, and left ventricular ejection fraction (LVEF) was quantified by echocardiography. Participants with carotid stenosis were excluded. Data were analyzed by multivariate linear regression.

Results

We included 8567 participants, median age was 62 years, 51.8% were women. Median CIMT was 0.75 mm, NT-proBNP 80 pg/ml, LVEF 58.5%, and 30.4% had carotid plaques. For women PSV decreased in decades from 89 to 73 cm/s in CCAs and 78 to 66 cm/s in ICAs, and for men from 91 to 76 cm/s in CCAs and from 70 to 66 cm/s in ICAs. Corrected for age, sex, red blood cell count, and blood pressure, in CCAs lower PSV was associated with carotid plaques (p < 0.001; β = -0.03), lower CIMT (p = 0.005; β = 0.007), higher levels of log-transformed NT-proBNP (p < 0.001; β = -0.01), and lower LVEF (p < 0.001; β = 0.01). In ICAs, lower PSV was independently associated with lower CIMT (p < 0.001; β = 0.02) and lower EF (p = 0.001; β = 0.007).

Conclusions

Markers of cardiac dysfunction and plaques are associated with lower and CIMT with higher flow velocities in the carotid arteries.

Clinical Trial Registration

http://www.clinicaltrials.gov, NCT03934957.

Duplex Ultrasound Surveillance after Transcarotid Artery Revascularization (TCAR) in Clinical Practice

BACKGROUND

To propose a protocol for the routine clinical use of duplex ultrasound (DUS) assessment after transcarotid artery revascularization (TCAR) procedures, with its specific point of vascular access, based on DUS data from routine clinical practice.

METHODS

DUS data were retrospectively collected at 2 centers from a total of 97 patients who underwent a TCAR procedure with at least 30-day and up to 12-month follow-up. Peak systolic velocity (PSV), end diastolic velocity (EDV), and the internal carotid artery (ICA)/common carotid artery (CCA) PSV ratio were collected at baseline (≤30 days after the procedure) and compared with subsequent measurements.

RESULTS

Baseline data were established within 30 days after the procedure. There were no access site stenoses, pseudoaneurysms, or dissections detected in follow-up. Average hemodynamics measurements at 12 months after the procedure (36% of patients reached this time point to date) were PSV 167 ± 153 cm/sec, EDV 51 ± 55 cm/sec, and ICA/CCA PSV 2.3 ± 1.9. Five patients (5.2%) exhibited velocities indicative of ≥80% in-stent restenosis (ISR) at 12 months after the procedure. Two patients (2.1%) underwent repeat intervention for ISR based on high velocities and before significant clinical consequence. The other 3 patients (3.1%) were asymptomatic and are being managed medically and monitored for neurological symptoms. One intraprocedural stroke (1.0% of total treated) was observed.

CONCLUSIONS

This protocol not only illustrates the utility of using the CCA for the arterial access sheath for carotid stenting, but also successfully identifies patients with clinically significant restenosis >80%-99%. A surveillance regimen of baseline at ≤30 days after the procedure, followed by assessment at 6 and 12 months, and yearly thereafter appears to be a safe and effective protocol, based on the data available to date. A PSV >340 cm/sec and ICA/CCA ratio >4.15 is consistent with an 80-99% restenosis after TCAR. Although a small number, this study serves as a starting point for those who perform TCAR to specifically look at the CCA access site to rule out these potential pitfalls which did occur in the early trials.

Effect of post-labeling delay on regional cerebral blood flow in arterial spin-labeling MR imaging

BACKGROUND

Investigating the effect of post-labeling delay (PLD) on regional cerebral blood flow (CBF) in adults and optimizing the PLD for arterial spin-labeling (ASL) magnetic resonance (MR) imaging are important.

METHODS

Pseudo-continuous ASL imaging with a three PLDs protocol was performed in 90 healthy adult volunteers from January 2018 to February 2019. Healthy subjects were divided into youth group (mean age, 30.63 years; age range, 20-44 years), middle-aged group (mean age, 52.16 years; age range 45-59 years) and elderly group (mean age, 66.07 years; age range, 60-77 years). After preprocessing, analyses of variance (ANOVA) and volume-of-interest (VOI) were conducted to compare the CBF in each brain region. According to the trends of CBF changing with PLD and the results of ANOVA, we optimized the PLD for ASL imaging in different brain regions and age groups.

RESULTS

The CBF values of 87 VOIs [global gray matter (global GM) and other 86 VOIs] for each subject were obtained. Young people had less statistically significant VOIs than middle-aged and elderly people [Numbers of VOIs which had statistical significance (P < .05) in the analysis of ANOVA: 42 (youth group), 79 (middle-aged group), and 71 (elderly group)]. In youth group, the deep GM, occipital lobe and temporal lobe were more affected by PLDs than limbic system, frontal lobe and parietal lobe [VOIs with statistical significance (P < .05)/total VOIs: 8/8 (deep GM) > 8/12 (occipital lobe) > (8/14) (temporal lobe) > 5/12 (limbic system) > 11/28 (frontal lobe) > (2/12) parietal lobe]. In middle-aged group, the limbic system, deep GM and temporal lobe were more affected by PLDs than parietal lobe, frontal lobe and occipital lobe [VOIs with statistical significance (P < 0.05)/total VOIs: 12/12 (limbic system) = 8/8 (deep GM) > (13/14) (temporal lobe) > (11/12) parietal lobe > 25/28 (frontal lobe) > 9/12 (occipital lobe)]. In elderly group, the temporal lobe, parietal lobe, and frontal lobe were more affected by PLDs than occipital lobe, limbic system, and deep GM [VOIs with statistical significance (P < .05)/total VOIs: 14/14 (temporal lobe) > 12/12 (parietal lobe) > 22/28 (frontal lobe) > 9/12 (occipital lobe) > 8/12 (limbic system) > 5/8 (deep GM)]. The optimal PLD for most VOIs in youth group was 1525 ms. However, for middle-aged and elderly group, the optimal PLD for most VOIs was 2525 ms.

CONCLUSION

Young people are less affected by PLDs than middle-aged and elderly people. The middle-aged people are most affected by PLDs. In addition, the spatial distributions of PLD effect were different among the three age groups. Optimizing the PLD for ASL imaging according to age and brain regions can obtain more accurate and reliable CBF values.

Autodetect extracranial and intracranial artery stenosis by machine learning using ultrasound

BACKGROUND

and Purpose: This study proposed a machine learning method for identifying ≥50% stenosis of the extracranial and intracranial arteries.

PATIENTS AND METHODS

A total of 8211 patients with both carotid ultrasound and cerebral angiography were enrolled. Support vector machine (SVM) was employed as the machine learning classifier. Carotid Doppler parameters and transcranial Doppler parameters were used as the input features. Feature selection was performed using the Extra-Trees (extremely randomized trees) method.

RESULTS

For the machine learning method, the sensitivities and specificities of identifying stenosis of the extracranial arteries were 88.5%-100% and 96.0%-100%, respectively. The sensitivities and specificities of identifying stenosis of the intracranial arteries were 71.7%-100% and 88.9%-100%, respectively.

CONCLUSIONS

The SVM classifier with feature selection is an efficient method for identifying the stenosis of both intracranial and extracranial arteries. Comparing with traditional Doppler criteria, this machine learning method achieves up to 20% higher in accuracy and 45% in sensitivity, respectively.

Focus on echovascular imaging assessment of arterial disease: complement to the ESC guidelines (PARTIM 1) in collaboration with the Working Group on Aorta and Peripheral Vascular Diseases

The main goal of the present document is to provide a set of practical recommendations for ultrasound imagers who are interested in artery diseases or for physicians who intend to undertake vascular procedures. This is the first part of the work. It is dedicated to general principles of ultrasonography, cervicoencephalic, subclavian, aortoiliac and lower extremity arteries, abdominal aorta, and popliteal aneurysms. It also discusses miscellaneous items such as medial arterial calcinosis, arterial embolism, arteritis, arterial stents and bypasses, false aneurysms, aortic dissection, popliteal entrapment syndrome, and iliac endofibrosis.

Ultrasound assessment of carotid arteries: Current concepts, methodologies, diagnostic criteria, and technological advancements

Following cardiac disease and cancer, stroke continues to be the third leading cause of death and disability due to chronic disease in the developed world. Appropriate screening tools are integral to early detection and prevention of major cardiovascular events. In a carotid artery, the presence of increased intima-media thickness, plaque, or stenosis is associated with increased risk of a transient ischemic attack or a stroke. Carotid artery ultrasound remains a long-standing and reliable tool in the current armamentarium of diagnostic modalities used to assess vascular morbidity at an early stage. The procedure has, over the last two decades, undergone considerable upgrades in technology, approach, and utility. This review examines in detail the current state and usage of this integrally important means of extracranial cerebrovascular assessment.

Determining the optimal postlabeling delay for arterial spin labeling using subject-specific estimates of blood velocity in the carotid artery

BACKGROUND

Arterial spin labeling with 3D acquisition requires determining a single postlabeling delay (PLD) value. PLD affects the signal-to-noise ratio (SNR) per unit time as well as quantitative cerebral blood flow (CBF) values due to its bearing on the presence of a vascular signal.

PURPOSE

To search for an optimal PLD for pseudocontinuous arterial spin labeling (pCASL) using patient-specific carotid artery blood velocity measurements.

STUDY TYPE

Prospective.

SUBJECTS

A control group of 11 volunteers with no known pathology. Corroboration was through a separate group of six volunteers and a noncontrol group of five sickle cell disease (SCD) patients.

FIELD STRENGTH/SEQUENCE

Pseudocontinuous arterial spin labeling with 3D nonsegmented echo planar imaging acquisition at 3T.

ASSESSMENT

A perfusion-based measure was determined over a range of PLDs for each of 11 volunteers. A third-order polynomial was used to find the optimal PLD where the defined measure was maximum. This was plotted against the corresponding carotid artery velocity to determine a relationship between the perfusion measure and velocity. Corroboration was done using a group of six volunteers and a noncontrol group of five patients with SCD. PLD was determined from the carotid artery velocity and derived relationship and compared with optimal PLD obtained from measured perfusion over a range of PLD values. Error between the perfusion measure at predicted and measured optimal PLD was determined.

STATISTICAL TESTS

Chi-squared goodness of fit; Pearson correlation; Bland-Altman.

RESULTS

Carotid artery velocity was 63.8 ± 6.6 cm/s (53.1 ≤ v ≤ 72.3 cm/s) while optimal PLD was 1374 ± 226.5 msec (1102 ≤ PLD ≤ 1787 msec) across the 11 volunteers. PLD as a function of carotid velocity was determined to be PLD = -31.94. v + 3410 msec (Pearson correlation -0.93). In six volunteers, mean error between the perfusion measure at predicted and measured optimal PLD was 1.35%. Pearson correlation between the perfusion measure at the predicted PLD and the measure obtained experimentally was r = 0.96 (P < 0.001). Bland-Altman revealed a slight bias of 1.3%. For the test case of five SCD patients, the mean error was 1.3%.

DATA CONCLUSION

Carotid artery velocity was used to determine optimal PLD for pCASL with 3D acquisition. The derived relationship was used to predict optimal PLD and the associated perfusion measure, which was found to be accurate when compared with its measured counterpart.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;50:951-960.

Factors Affecting Microvascular Responses in the Bulbar Conjunctiva in Habitual Contact Lens Wearers

Purpose

To investigate the factors affecting microvascular responses in the bulbar conjunctiva of habitual contact lens (HCL) wearers.

Methods

A functional slit-lamp biomicroscope (FSLB) was used to image the temporal bulbar conjunctiva of habitual contact lens (HCL) wearers and non-contact lens (NCL) wearers. The vessel diameters and blood flow velocities (BFVs) were measured. Fractal analysis using Dbox as vessel density and D0 as vessel complexity were used to quantitatively analyze the microvascular network. One eye each of 91 NCL wearers and 75 HCL wearers was imaged.

Results

The BFV of NCL wearers was 0.50 ± 0.14 mm/s, which was negatively correlated with age (r = -0.22, P < 0.05). The BFV, vessel diameter, Dbox, and D0 of HCL wearers was significantly higher than NCL wearers (P < 0.05). In these HCL wearers, BFVs were positively correlated with contact lens (CL) hours of wear per day and CL days of wear per week. BFV, Dbox, and D0 were not related to CL years of wear, CL power, CL base curve, and CL diameter (P > 0.05).

Conclusions

Vascular responses on the bulbar conjunctiva occurred in HCL wearers and appeared to be unrelated to sex or age, CL years of wear, and lens parameters, indicating that wearing a CL itself may be the predominant factor inducing these responses.

Is Carotid Stenosis in Women a Gender-Related Condition?

BACKGROUND

We set out to study, through ultrasound examinations, the carotid bifurcation in men and women with/without carotid stenosis to look for anatomical and electrophysiologic differences. We evaluated other variables to look for differences that might explain the dissimilar behavior of this disease in the two sexes and the presence and impact of risk factors.

METHODS

We examined 974 subjects aged 25 to 88 years (478 men and 496 women) in whom we considered heart rate, smoking status, and the presence of hypertension, diabetes, hypercholesterolemia, and hypertriglyceridemia. Ultrasound examination of the neck vessels included measurement of intimal medial thickness (IMT), vessel diameter, and outflow area/inflow area ratio. We established plaque location, echogenicity and echostructure, and the percentage of stenosis owing to plaque and measured systolic velocity, flow direction, and the depth of detection of these parameters. We used the apnea and hyperpnea test to assess cerebrovascular reactivity.

RESULTS

Hypertension and hypercholesterolemia were the most frequent risk factors. Women had a higher heart rate, whereas men had significantly greater IMT. The presence of atheromatous plaque was significantly correlated with age in both sexes, with men having a higher prevalence of carotid plaques. The sexes differed significantly with regard to plaque location, echogenicity, echostructure, and intracranial circulation. Women had a slightly higher blood flow velocity in the intracranial arteries. Risk factors affected plaque formation and extent more in men than in women.

CONCLUSIONS

These findings suggest that carotid stenosis is a gender-related trait.

Meta- analysis and meta-regression analysis of the associations between sex and the operative outcomes of carotid endarterectomy

Background

Subgroup analyses from randomized controlled trials (RCT) of carotid endarterectomy (CEA) for both symptomatic and asymptomatic carotid stenosis suggest less benefit in women compared to men, due partly to higher age-independent peri-operative risk. However, a meta-analysis of case series and databases focussing on CEA-related gender differences has never been investigated.

Methods

A systematic review of all available publications (including case series, databases and RCTs) reporting data on the association between sex and procedural risk of stroke and/or death following CEA from 1980 to 2015 was investigated. Pooled Peto odds ratios of the procedural risk of stroke and/or death were obtained by Mantel-Haenszel random-effects meta-analysis. The I² statistic was used as a measure of heterogeneity. Potential publication bias was assessed with the Egger test and represented graphically with Begg funnel plots of the natural log of the OR versus its standard error. Additional sensitivity analyses were undertaken to evaluate the potential effect of key assumptions and study-level factors on the overall results. Meta-regression models were formed to explore potential heterogeneity as a result of potential risk factors or confounders on outcomes. A tria sequential analysis (TSA) was performed with the aim to maintain an over- all 5 % risk of type I error, being the standard in most meta- analyses and systematic reviews.

Results

58 articles reported combined stroke and mortality rates within 30 days of treatment. In the unselected overall meta-analysis, the incidence of stroke and death in the male and female groups differed significantly (Peto OR, 1,162; 95 % CI, 1.067-1.266; P = .001), revealing a worse outcome for female patients. Moderate heterogeneity among the studies was identified (I² = 36 %), and the possibility of publication bias was low (P = .03). In sensitivity analyses the meta-analysis of case series with gender aspects as a secondary outcome showed a significantly increased risk for 30-day stroke and death in women compared to men (Peto OR, 1.390; 95 % CI, 1.148-1.684; P = .001), In contrast, meta-analysis of databases (Peto OR, 1.025; 95 % CI, 0.958-1.097; P = .474) and case series with gender related outcomes as a primary aim (Peto OR, 1.202; 95 % CI, 0.925-1.561; P = .168) demonstrated no increase in operative risk of stroke and death in women compared to men.

Conclusions

Metanalyses of case series and databases dealing with CEA reveal inconsistent results regarding gender differences related to CEA-procedure and should not be transferred into clinical practice.

Management of extracranial carotid artery disease

Stroke is the third leading cause of death in developed nations. Up to 88% of strokes are ischemic in nature. Extracranial carotid artery atherosclerotic disease is the third leading cause of ischemic stroke in the general population and the second most common nontraumatic cause among adults younger than 45 years. This article provides comprehensive, evidence-based recommendations for the management of extracranial atherosclerotic disease, including imaging for screening and diagnosis, medical management, and interventional management.

Carotid artery stenting is safe and associated with comparable outcomes in men and women

OBJECTIVE

Historically, large randomized controlled studies looking at carotid endarterectomy (CEA) have indicated an increased perioperative risk for women when gender subgroup analysis was performed. However, the outcomes of carotid stenting in women as compared to men have not been adequately investigated. We sought to compare the safety and efficacy of carotid angioplasty and stenting (CAS) when performed in women as compared to men.

METHODS

Procedures, complications, demographics, co-morbidities, and follow-up data from carotid stenting procedures performed in a bi-campus division were entered into a prospective database and then retrospectively supplemented with stored angiographic image data and reviewed. Arterial anatomic characteristics evaluated using angiographic images were: common carotid/internal carotid lesion length ratio, common carotid/internal carotid diameter, index lesion length, common carotid/internal carotid artery tortuosity, and lesion and aortic arch calcification. Outcomes compared included groin complications, postoperative pressor requirements, length of stay, restenosis, stroke, myocardial infarction (MI), and death.

RESULTS

Between 2003 and 2008, 228 patients underwent 238 procedures. Cerebral protection devices and self-expanding stents were placed in all patients. A total of 97 percutaneous interventions performed in 93 women were compared with 141 interventions in 135 men. Mean age in women was 71.8 +/- 9.2 years, in men was 72.2 +/- 9.1 years (P > .99); 44.3% of women and 34.7% of men had symptomatic disease (P = .14). Preoperative demographics and co-morbidities did not differ significantly between genders, with the exception of hypertension (83.0% of males vs 96.7% of females, P = .001), and history of coronary artery bypass grafting (31.8% of males vs 16.1% of females, P = .01). There were no significant differences seen in anatomic arterial characteristics, though there was a trend towards women having larger internal carotid to common carotid diameter ratios (0.65 vs 0.62) and more plaques isolated to the common carotid segment (9.5% vs 6.9%). There were no significant differences seen in overall 30-day peri-procedural stroke rate (2.1% in women and 4.2% in men, P = .48), death rate (0 % vs 0.7%, P > .99), or cardiac events (3.2% vs 0.7%, P = .3). The combined 30-day stroke, death, and MI rate was 5.7% for males compared to 5.4% for females (P > .99). There were no differences observed in the long-term survival, stroke-free survival, or restenosis between genders.

CONCLUSION

Despite previous concerns over adverse outcomes in women undergoing carotid endarterectomy, from our data, carotid stenting appears to be a safe modality in women with equivalent outcomes when compared to men.

Carotid Doppler velocity measurements and anatomic stenosis: correlation is futile

BACKGROUND

Duplex ultrasound with Doppler velocimetry is widely used to evaluate the presence and severity of internal carotid artery stenosis; however, a variety of velocity criteria are currently being applied to classify stenosis severity. The purpose of this study is to compare published Doppler velocity measurements to the severity of internal carotid artery stenosis as assessed by x-ray angiography in order to clarify the relationship between these 2 widely used approaches to assess carotid artery disease.

METHODS

Scatter diagrams or "scattergrams" of correlations between Doppler velocity measurements and stenosis severity as assessed by x-ray contrast angiography were obtained from published articles for native and stented internal carotid arteries. The scattergrams were graphically digitized, combined, and segmented into categories bounded by 50% and 70% diameter reduction. These data were combined and divided into 3 sets representing different velocity parameters: (1) peak systolic velocity, (2) end-diastolic velocity, and (3) the internal carotid artery to common carotid artery peak systolic velocity ratio. The horizontal axis of each scattergram was transformed to form a cumulative distribution function, and thresholds were established for the stenosis categories to assess data variability.

RESULTS

Nineteen publications with 22 data sets were identified and included in this analysis. Wide variability was apparent between all 3 velocity parameters and angiographic percent stenosis. The optimal peak systolic velocity thresholds for stenosis in stented carotid arteries were higher than those for native carotid arteries. Within each category of stenosis, the variability of all 3 velocity parameters was significantly lower in stented arteries than in native arteries.

CONCLUSION

Although Doppler velocity criteria have been successfully used to classify the severity of stenosis in both native and stented carotid arteries, the relationship to angiographic stenosis contains significant variability. This analysis of published studies suggests that further refinements in Doppler velocity criteria will not lead to improved correlation with carotid stenosis as demonstrated by angiography.

Analysis of Florida and New York state hospital discharges suggests that carotid stenting in symptomatic women is associated with significant increase in mortality and perioperative morbidity compared with carotid endarterectomy

BACKGROUND

Although large randomized studies have established the efficacy and safety of carotid endarterectomy (CEA) and, recently, carotid artery stenting (CAS), the under-representation of women in these trials leaves the comparison of risks to benefits of performing these procedures on women an open question. To address this issue, we reviewed the hospital outcomes and delineated patient characteristics predicting outcome in women undergoing carotid interventions using New York and Florida statewide hospital discharge databases.

METHODS

We analyzed in-hospital mortality, postoperative stroke, cardiac postoperative complications, and combined postoperative stoke and mortality in 20,613 CEA or CAS hospitalizations for the years 2007 to 2009. Univariate and multiple logistic regression analyses of variables were performed.

RESULTS

CEA was performed in 16,576 asymptomatic and 1744 symptomatic women and CAS in 1943 asymptomatic and 350 symptomatic women. Compared with CAS, CEA rates, in asymptomatic vs symptomatic, were significantly lower for in-hospital mortality (0.3% vs 0.8% and 0.4% vs 3.4%), stroke (1.5% vs 2.6% and 3.5% vs 9.4%), and combined stroke/mortality (1.7% vs 3.1% and 3.8% vs 10.9%). In cohorts matched by propensity scores, the same trend favoring CEA remained significant in symptomatic women. There was no difference in cardiac complication rates among asymptomatic women, but among symptomatic woman cardiac complications were more frequent after CAS (10.6% vs 6.5%; P = .0077). Among symptomatic women, the presence of renal disease, coronary artery disease, or age ≥80 years increased the risk of CAS over CEA threefold for the composite end point of stroke or death. For asymptomatic women only in those with coronary artery disease or diabetes, there was a statistical difference in the composite mortality/stroke rates favoring CEA (1.9% vs 3.3% and 1.7% vs 3.4%, respectively). After adjusting for relevant clinical and demographic risk factors and hospital annual volume, for CAS vs CEA, the risk of the composite end point of stroke or mortality was 1.7-fold higher in symptomatic and 3.4-fold higher in asymptomatic patients. Medicaid insurance, symptomatic patient, history of cancer, and presence of heart failure on admission were among other strong predictors of composite stroke/mortality outcome.

CONCLUSIONS

Databases reflecting real-world practice performance and management of carotid disease in women suggest that CEA compared with CAS has overall better perioperative outcomes in women. Importantly, CAS is associated with significantly higher morbidity in certain clinical settings and this should be taken into account when choosing a revascularization procedure.

Mapeamento ecográfico da bifurcação das artérias carótidas extracranianas para planejamento cirúrgico: diferenças baseadas no gênero do paciente

CONTEXTO: A ecografia das artérias carótidas extracranianas já se estabeleceu como método diagnóstico de imagem pré-operatória, e para seguimento de pacientes. OBJETIVO: Avaliar diferenças do mapeamento ecográfico em função do gênero masculino ou feminino dos pacientes. MÉTODOS: Ultrassonografia de alta resolução foi realizada antes do tratamento cirúrgico de 500 bifurcações carotídeas em 192 mulheres e 308 homens. Análise de diferenças baseadas no gênero foi feita em imagens modo B e fluxo a cor, transversal e longitudinal, e medidas duplex doppler de velocidades. Porcentual de estenose expressa em redução de diâmetro, comprimento de placa, diâmetros das artérias carótida interna distal e comum, e distância da bifurcação ao lóbulo da orelha foram comparados. Média, desvio padrão, mínimo e máximo foram descritos. Comparações estatísticas foram baseadas em testes t de Student e do Χ2. RESULTADOS: Estenoses carotídeas mediram 70±11% (30-95%) em mulheres e 72±12% (40-98%) em homens (p=0,013). Prevalência de estenoses no intervalo 90-99% foi mais alta em homens, 14,3 vs 7,8% (p=0,029). As placas foram mais extensas nos homens, 2,3±0,8 vs 1,9±0,6 cm (p<0,001). O diâmetro médio foi maior nos homens, tanto da carótida interna distal, 4,9±0,9 vs 4,6±0,8 mm, como da carótida comum, 7,6±1,3 vs 7,1±1,4 mm (p=0.001). A distância da bifurcação ao lóbulo da orelha foi maior nos homens, 5,9±1,1 vs 5,3±0,9 cm (p<0,001). CONCLUSÕES: O mapeamento ecográfico demonstrou que as medidas analisadas foram maiores em pacientes do gênero masculino. O planejamento detalhado do tratamento da placa carotídea deve considerar diferenças individuais como as associadas ao gênero do paciente.

Different cerebral hemodynamic responses between sexes and various vessels in orthostatic stress tests

OBJECTIVE

The argument about why the head-up tilt table test (HUT) does not include the posterior cerebral circulation, which is mainly responsible for syncope, as a monitor target has not been resolved. It is also unclear whether there is a sex difference in cerebral blood flow (CBF) changes. We hypothesized that orthostatic CBF changes more in the posterior circulation than in the anterior circulation and is different between sexes.

METHODS

Thirty healthy volunteers (13 female and 17 male) were recruited for the HUT. The blood pressure (BP), middle cerebral artery flow velocity (MCAFV), and posterior cerebral artery flow velocity (PCAFV) were monitored simultaneously. Static cerebral autoregulation (CA) was calculated.

RESULTS

The female volunteers had a lower BP, but there was no difference in orthostatic BP changes (female versus male: 1.29% +/- 5.26% versus 4.22% +/- 12.65%; P = .65). The female volunteers had a significantly greater orthostatic drop in the PCAFV than in the MCAFV (23.8% +/- 9.1% versus 18.2% +/- 7.3%; P = .008). The static CA in the middle cerebral artery was better than in the posterior cerebral artery, although not significantly (13.6% +/- 34.8% versus - 2.8% +/- 12.2%; P = .15).

CONCLUSIONS

Our study showed the different cerebral hemodynamic responses between anterior and posterior circulations and between sexes during the HUT. We conclude that HUT studies for syncope should include the posterior cerebral circulation, especially for female patients.

Mechanisms of gender-related outcome differences after carotid endarterectomy

OBJECTIVE

Large randomized trials have confirmed a difference in outcome after carotid endarterectomy (CEA) between men and women. In this review, we aimed to provide an overview of the gender-specific characteristics causing these perioperative and long-term outcome differences between men and women after CEA.

METHODS

A systematic search strategy with the synonyms of 'gender' and 'carotid endarterectomy' was conducted from PubMed and EMBASE databases. Only 11 relevant studies specifically discussing gender-specific related characteristics and their influence on outcome after CEA could be identified.

RESULTS

Due to the limited number of included studies, pooling of findings was impossible, and results are presented in a descriptive manner. Each included study described only one possible gender-specific factor. Differences in carotid artery diameter, sex hormones, sensitivity for antiplatelet therapy, plaque morphology, occurrence of microembolic signals, and restenosis rate have all been suggested as gender-specific characteristics influencing outcome after CEA.

CONCLUSION

Higher embolic potential in women and relatively stable female plaque morphology are the best-described factors influencing the difference in outcomes between men and women. However, the overall evidence for outcome differences by gender-specific characteristics in the literature is limited.

Is female gender really a risk factor for carotid endarterectomy?

BACKGROUND

The aim of this study was to assess the effect of gender on mortality and morbidity in carotid endarterectomy (CEA) patients.

METHODS

Forty-one female and 150 male patients who underwent isolated CEA operations, between 1994 and 2007, were included in this study. To find the role of gender in isolated CEA operations, patients with a previous history of cardiac operations, coronary interventions, and a staged cardiac and/or vascular operation were excluded from the study.

RESULTS

In the postoperative period, one female patient (2.4%) and 8 male patients (4.9%) had neurological complications (p > 0.05). Hospital mortality rates of female and male groups were 0.0% and 2.4%, respectively (p > 0.05). Perioperative events which cause significant increase in hospital mortality were myocardial ischemia, low cardiac output, and need of intra-aortic balloon pump (p = 0.0001). Late mortality rates of female and male groups were 7.5% and 9.9%, respectively. The actuarial survival rate was 82.2 +/- 11.6% in women and 71.5 +/- 7.5% in men for a mean period of 36.4 +/- 29.1 months (p > 0.05). All the observed mortalities in the long term were cardiac-related or with other causes, no neurological deaths observed in both groups (p > 0.05). According to logistic regression analysis smoking and peripheral arterial disease were found as statistically significant risk factors for late mortality.

CONCLUSION

Female gender is not a risk factor for stroke or death after CEA. Women should not be excluded from the benefits of CEA and gender should not be a consideration in the decision to perform it.

Arterial vascular disease in women

BACKGROUND

Arterial disease in women will become a major issue in the near future.

METHODS

A systemic review of existing literature was retrospectively conducted to collect information on the three most common entities of vascular disease: carotid atherosclerotic, abdominal aortic aneurismal, and lower extremity arterial occlusive disease.

RESULTS

Vascular disease is either underdiagnosed or undertreated in women. Whether regarding cerebrovascular disease, aortic aneurysmal disease, or atherosclerosis affecting the lower extremities, natural history, clinical and physiologic patterns are different in women vs men. Current biomedical devices create challenges in endovascular procedures performed in women. Furthermore, indications for treatment of vascular disease are derived from large studies where women are often underrepresented; and, thus, may not be applicable in female vascular patients.

CONCLUSIONS

Better understanding of the gender differences in vascular disease with focused randomized trials, biomedical research, and identification of gender specific medical and social risk factors will improve the clinical outcomes in female patients.

Gender Differences in Blood Flow Velocities after Carotid Angioplasty and Stenting

Gender differences have been demonstrated in blood flow velocities by duplex ultrasonography (DU) in patients with carotid stenosis. Currently, DU is the most widely used method of follow-up monitoring after carotid angioplasty and stenting (CAS). To identify possible gender differences in carotid flow velocities, we analyzed our experience with DU obtained before and immediately after CAS. In a series of 47 CAS procedures over a 2.5-year period performed in 31 men and 15 women, carotid angiograms and duplex flow velocities were obtained preoperatively and within 24 hr after CAS. Carotid velocity profiles were compared with the angiographic degree of carotid stenosis. Gender differences in blood velocities were assessed using parametric and nonparametric statistical tests. Overall, women had median blood velocities 5-10% higher than men, although the differences were not statistically significant. DU obtained immediately after CAS revealed that median blood flow velocities were very similar among men and women (P > 0.4). In conclusion, although women have higher carotid blood flow velocities than men do, gender differences are notably absent on follow-up DU after carotid stenting. Our data indicate that similar criteria should be used after CAS for interpreting carotid velocity profiles in both women and men.

Carotid Ultrasound Criteria for Detecting Intracranial Carotid Stenosis

BACKGROUND/AIMS

This study attempted to establish carotid ultrasound criteria for identifying stenosis of the intracranial internal carotid artery (ICA) and middle cerebral artery (MCA).

METHODS

Two hundred and fifty-five patients were enrolled. Ultrasound measurements for common carotid artery (CCA) and ICA were as follows: flow volume (FV), peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI) and resistance index (RI). The sensitivity and specificity of the ultrasound criteria for determining intracranial ICA or MCA>or=50% stenosis were calculated.

RESULTS

The criteria identified for detecting intracranial ICA>or=50% stenosis were ICA FV<159 ml/min, ICA PSV<33 cm/s and CCA PSV<42 cm/s. When ICA PSV<33 cm/s was combined with CCA PSV<42 cm/s, sensitivity increased to 82%, with 91% specificity. The criteria identified for detecting MCA>or=50% stenosis were CCA FV<285 ml/min, ICA FV<179 ml/min, ICA PSV<33 cm/s, >35% reduction in FV in the CCA, >40% reduction in FV in ICA, and >35% reduction in PSV in ICA. When these criteria were combined, sensitivity increased to 69%, with 85% specificity.

CONCLUSION

This study demonstrated that ultrasound criteria are sensitive and specific for detecting intracranial ICA and MCA significant obstruction.