Carotid Artery Peak Systolic Velocity Research Articles

Assessment of extracranial carotid artery disease using digital twins – A pilot study

To improve risk stratification in extracranial internal carotid artery disease (CAD), patients who would benefit maximally from revascularization must be identified. In cardiology, the fractional flow reserve (FFR) has become a reference standard for evaluating the functional severity of coronary artery stenosis, and noninvasive surrogates thereof relying on computational fluid dynamics (CFD) have been developed. Here, we present a CFD-based workflow using digital twins of patients’ carotid bifurcations derived from computed tomography angiography for the noninvasive functional assessment of CAD. We reconstructed patient-specific digital twins of 37 carotid bifurcations. We implemented a CFD model using common carotid artery peak systolic velocity (PSV) acquired with Doppler ultrasound (DUS) as inlet boundary condition and a two-element Windkessel model as oulet boundary condition. The agreement between CFD and DUS on the PSV in the internal carotid artery (ICA) was then compared. The relative error for the agreement between DUS and CFD was 9% ± 20% and the intraclass correlation coefficient was 0.88. Furthermore, hyperemic simulations in a physiological range were feasible and unmasked markedly different pressure drops along two ICA stenoses with similar degree of narrowing under comparable ICA blood flow. Hereby, we lay the foundation for prospective studies on noninvasive CFD-based derivation of metrics similar to the FFR for the assessment of CAD.

Defining Duplex Ultrasound Criteria for In-Stent Restenosis of the Carotid Artery Using Computed Tomographic Angiography.

IntroductionDuplex ultrasound (DUS) velocity measurement is the preferred method for evaluating carotid artery stenosis. However, velocity criteria based upon native carotid arteries may not apply to internal carotid artery stents. Previously, catheter-based angiography was used to determine DUS velocity criteria for in-stent restenosis (ISR), but conventional angiography is invasive and can be limited. This study sought to define duplex ultrasound velocity criteria for predicting internal carotid artery in-stent restenosis by correlating in-stent velocities with computed tomographic angiography (CTA) measurements of percent stenosis.MethodsA retrospective chart review was conducted on all patients who underwent internal carotid artery (ICA) stenting within our health system between January 2013 and February 2020. Thirty-eight surveillance DUS studies from 32 patients were found to have CTA performed within 30 days. Centerline reconstructions of internal carotid artery stents were created using Aquarius iNtuition software (TeraRecon, Durham, NC, USA). Two independent observers measured percent stenosis by three built-in methods. Stenotic areas were matched to DUS-measured peak systolic velocities (PSV) and end-diastolic velocities (EDV). Internal carotid artery PSV (stent) to common carotid artery (CCA) PSV ratios (ICA/CCA) were calculated, and receiver operating characteristic (ROC) curves were generated. The optimal DUS velocity criteria in the stented ICA were determined by maximizing Youden’s index.ResultsMean vessel diameter measurement of percent stenosis resulted in the most accurate model for all DUS velocity parameters (PSV, EDV, and ICA/CCA ratio) and was used for threshold determinations (area under the receiver operating characteristics (AUROC): 0.99, 0.96, and 0.96, respectively). A PSV cutoff of 240 cm/s for ≥60% ISR resulted in the highest Youden’s index (97%) with 100% sensitivity and 97% specificity. Secondary DUS parameters included an EDV ≥50 cm/s (Youden’s index 84%) and an ICA/CCA ratio ≥ 2.2 (Youden’s index 91%).ConclusionsVelocity criteria to predict internal carotid artery ISR is needed to inform decisions for possible reintervention. Using CTA, we found that a PSV ≥240 cm/s on carotid DUS can predict ≥60% ISR with high sensitivity and specificity. This value can be used as an alternative to current velocity criteria based on native carotid arteries. However, the optimal thresholds for EDV and ICA/CCA ratio were similar to native carotid arteries.

Evaluation of extracranial carotid flow velocities in patients presenting with acute ischemic stroke: A clinical study conducted in Turkey

Objective. The mechanism underlying the relationship between carotid flow velocities and stroke events remains unclear. This study aimed to reveal the relationship of flow velocity measurements with risk factors in patients with acute ischemic stroke. Material and methods. A group of patients between the ages of 41-90 who applied to Mengücek Training and Research Hospital in the Eastern Anatolia Region of Turkey between 2014-2015 due to acute ischemic stroke were included. Groups with large artery atherosclerosis and small-vessel occlusion according to the Toast classification were included in the study. Brain tomography and magnetic resonance imaging, echocardiography, high-resolution color Doppler Ultrasonography examinations were performed. Internal carotid artery peak-systolic and end-diastolic flow velocity, common carotid artery peak-systolic and end-diastolic flow velocity, internal carotid artery peak systolic-common carotid artery peak-systolic velocity ratio and common carotid artery intima-media thickness were measured with Doppler Ultrasonography. The relationship between carotid flow velocities and brain infarction volume, comorbid factors, biochemical variables, left ventricular systolic-diastolic dysfunction was defined by using Statistical Package for Social Sciences version 21.0. Outcomes. In acute ischemic stroke groups, a significant negative correlation between common carotid artery end-diastolic flow velocity and brain infarction volume, a significant positive relationship between common carotid artery peak-systolic velocity and smoking, a significant positive correlation between common carotid artery intima-media thickness and blood glucose and hba1c, a significant negative correlation between common carotid artery end-diastolic flow velocity and hypertension, a significant relationship between common carotid artery end-diastolic flow velocity and ischemic heart disease, an increase in cerebral infarction in patients with left ventricular systolic dysfunction and a decrease in Internal carotid artery peak-systolic flow velocity in patients with left ventricular diastolic dysfunction were detected. Conclusions. In clinical practice, Doppler ultrasound is currently the main diagnostic tool for evaluating the diagnosis of carotid stenosis. In stenosis in the carotid artery system, it should be known as a basic rule that the flow velocity in the stenosis area increases, except for in severe stenosis and four basic measurements should be made to determine the degree of stenosis clearly. These measurements are peak systolic flow velocity (PSV), end-diastolic flow velocity (EDV), peak-systolic flow velocity ratio (ICA/CCA PSV). The purpose of sonographic evaluation of the extracranial cerebral arteries is to prevent bad sequelae and permanent deficits together with cerebral infarction.

Carotid ultrasound following transcarotid transcatheter aortic valve replacement

BackgroundTranscarotid (TC) is a common alternative access for transcatheter aortic valve replacement (TAVR) when the transfemoral route is not suitable. However, scarce data exist on systematic ultrasound (US) follow-up of these patients. This study aims to evaluate the safety of TC-TAVR using pre-and post-procedure carotid artery US assessment. MethodsWe performed an observational prospective study including 50 consecutive patients who underwent TC-TAVR that had a follow-up at our institution between September 2016 and July 2020. ResultsAll patients had a carotid US examination at a median time of 13 months (IQR: 5–17) following the procedure. Thirty-six (71%) patients also had a US examination prior to the procedure. Mean pre-procedural access route common carotid artery (AR-CCA) peak systolic velocity (PSV) was 62.9 cm/s (SD:16.8) vs. 69.0 cm/s (SD: 53.4) in the contralateral CCA (CL-CCA), p = 0.562). There was a significant increase in post-procedural PSV values in the AR-CCA (30.3 cm/s (SD: 36.3), p < 0.001) but not in the CL-CCA (5.8 cm/s (SD: 51.7), p = 0.503). Two new carotid stenoses (4%) were diagnosed after the procedure. No baseline or procedural variables were associated with a higher increase in carotid flow velocities at follow-up. There were no cerebrovascular events related to these findings after a median follow-up of 29 months (IQR:13–33). ConclusionsTC-TAVR was associated with a mild but significant increase in carotid flow velocities, with new significant (>50%) carotid stenosis diagnosed in 4% of patients. These findings were not associated with clinical events after a median follow-up of 2 years. Further studies are warranted.

Assessment of role of inferior vena cava collapsibility index and variations in carotid artery peak systolic velocity in prediction of post-spinal anaesthesia hypotension in spontaneously breathing patients: An observational study.

Background and Aims:Post-spinal anaesthesia hypotension (PSH) is common and can lead to significant morbidity and mortality. The inferior vena cava collapsibility index (IVCCI) and carotid artery peak systolic velocity variations (CAPVV) are two widely used parameters for assessing the volume status of critically ill patients which have also been investigated as predictors of PSH and hypotension after induction of general anaesthesia. In this study, we evaluated the diagnostic accuracy of IVCCI and CAPVV as predictors of PSH.Methods:A total of 50 patients aged between 18 and 65 years undergoing elective lower abdominal surgeries under spinal anaesthesia were included. The IVCCI and CAPVV were measured using ultrasound pre-operatively. After administering spinal anaesthesia, haemodynamic data were collected till 15 min. Our primary objective was to evaluate the role of IVCCI and CAPVV to predict PSH. The secondary objectives were to compare the predictive efficacy of these two parameters and to detect other parameters for predicting PSH. We constructed the receiver operator characteristic (ROC) curves for IVCCI and CAPVV and obtained the best cut-off values.Results:The PSH occurred in 34% of the patients. IVCCI >21.15 could predict PSH with 58.8% sensitivity and 69.7% specificity. CAPVV >18.33 predicted PSH with 70.6% sensitivity and 54.6% specificity and IVC max/IVCCI >60 could predict PSH with 58.8% sensitivity and 54.5% specificity. A composite model comprising IVCmax (maximum IVC diameter), CAPVV, and baseline mean blood pressure was able to predict PSH.Conclusion:Both IVCCI and CAPVV have poor diagnostic accuracy in predicting PSH in adult patients undergoing elective infra-umbilical surgery.

Explore the correlation between cerebral vessel characteristics with cognitive impairment among elder individuals: a community study from China

BackgroundBrain Magnetic Resonance Imaging (MRI) examination of cerebral small vessel disease (CSVD) may help screen vascular cognitive impairment. A recently estimated CSVD score system was suggested to capture the overall CSVD burden. The study aimed to detect the association between systemic evaluation score of cerebral vascular imaging parameters with cognitive functions.MethodsThis was a cross-sectional study in community settings. From October 2017 to September 2018, elder (≧60) residents were recruited through on-site visit in 6 communities from Shanghai, China. The participants underwent brain MRI, carotid ultrasound, laboratory tests of blood and urine samples. Cognitive function was evaluated using Mini-Mental State Examination (MMSE). MRI score of CSVD was calculated according to the 2012 standard for the evaluation of statistical changes in imaging.ResultsTotal 171 subjects completed survey and examinations. There were 55 participants diagnosed with cognitive impairment, with a total percentage of 32.2%. Participants with and without cognitive impairment showed significant differences in age, BMI and education level. Cognitive impaired participant had more disease history/comorbidity of hypertension and chronic renal insufficiency, higher level of creatinine, as well as lower level of full blood count (FBC) and alanine aminotransferase (ALT). A significant difference was detected in CSVD score between participants with and without cognitive impairment. Results of linear regression analysis showed significant negative correlations between MMSE score and both left and right carotid artery peak systolic velocity (PSV), however the CSVD score was only borderline (P = 0.0566) positively correlated with MMSE. Multivariate linear correlation analysis including all collected risk factor data showed that left carotid artery PSV score was among the independent negative correlated factors of MMSE. Multivariate binary logistic analysis showed that age, education and history of hypertension were the only statistically associated factors of cognitive impairment.ConclusionsThe current study identified high prevalence of cognitive impairment in a Chinese community. In addition, correlations between cerebral vascular disease imaging status and cognitive functions were confirmed although the sample size limited the possibility of screening cognitive impairment with imaging technique.

Comparison between conventional duplex ultrasonography and the dual-gate Doppler mode for hemodynamic measurements of the carotid arteries.

PurposeThis study investigated the correlations of hemodynamic parameters measured to quantify stenosis between the gold-standard duplex ultrasonography and the dual-gate Doppler mode.MethodsPatients examined due to suspicion of carotid artery stenosis or for surveillance of known stenosis were invited to participate in this prospective single-center study. Upon acceptance, the hemodynamic characteristics of the carotid arteries were determined successively in standard duplex and dual-gate Doppler modes. The correlations between the two modes were analyzed by computing Pearson coefficients (r2) and Lin concordance coefficients (ρc). The degree of agreement between the two methods was visualized using Bland-Altman graphical representations.ResultsThe correlation between internal carotid artery peak systolic velocity measured by standard duplex ultrasonography and dual-gate Doppler mode was good (r2=0.642). The same high level of correlation was observed for the carotid ratio (r2=0.544). However, the Bland-Altman graphical representation and the Lin concordance coefficients (ρc=0.75 and ρc=0.74 for the internal carotid artery peak systolic velocity and carotid ratio, respectively) showed that a lack of precision generated some discrepancies between the two measurement methods.ConclusionAlthough some discrepancies were observed, the hemodynamic measurements were closely correlated between the two ultrasonography modes. Therefore, the dual-gate Doppler mode may have obvious advantages over conventional ultrasonography, offering interesting development possibilities.

The association between pulsatile tinnitus and degree of carotid stenosis

Background A pulsatile tinnitus may be the first and sole manifestation of carotid artery atherosclerosis and stenosis. The objective of this study was to detect the association between pulsatile tinnitus and degree of carotid stenosis by carotid Doppler ultrasound parameters. Patients and methods This prospective cross-sectional analytical study has been conducted on 40 selective cases complaining from pulsatile tinnitus. Carotid duplex ultrasonography scanning was done. Research has been approved by the Research Ethical Committee of Otolaryngology Department, Faculty of Medicine for Girls, AL-Azhar University. Results Carotid artery atherosclerosis and stenosis were diagnosed as a cause of pulsatile tinnitus in five patients (12.5%). The internal carotid artery (peak systolic velocity and end diastolic velocity) values were significantly higher in patients whose intima-media thickness was greater than 1 mm and the lumen diameters were smaller. Conclusion A pulsatile tinnitus may be the first, unusual, and sole manifestation of carotid artery atherosclerosis and stenosis. So, early screening and accurate diagnosis of atherosclerosis will prevent stroke and other central nervous system complications.

A Reappraisal of CT Angiography Derived Duplex Ultrasound Velocity Criteria With a Comparison to Digital Subtraction Angiography in Patients With Carotid Artery Stenosis

Traditionally, carotid duplex ultrasound (CDUS) velocity criteria have been derived from angiography. Recent studies support a shift toward computed tomography angiography (CTA) derived velocity criteria; however, they lack a comparison to angiography. The purposes of this study are to validate CTA derived measurements with digital subtraction angiography (DSA) and to update our previous CTA-derived velocity criteria for 50% and 80% stenosis. All patients between 2010 and 2019 who underwent CDUS and a neck CTA within 6 months were identified for a retrospective review. Vessel diameter and corresponding CDUS data were recorded. Additional DSA measurements were recorded for a subset of patients. Data from this cohort were added to a previously reported deidentified data set from patients between 2000 and 2009. Receiver operating characteristic (ROC) curves were generated to determine optimal velocity thresholds. Spearman rank correlation was used to correlate measurements obtained by CTA to those obtained by DSA. A total of 1139 vessels from 636 patients were analyzed. ROC analysis to identify ≥ 50% stenosis resulted in optimized thresholds of 143 cm/sec, 46.2 cm/sec, and 2.15 for peak systolic velocity (PSV), end-diastolic velocity (EDV), and PSV to common carotid artery PSV ratio (PSVR), respectively. ROC analysis to identify ≥ 80% stenosis resulted in optimized thresholds of 319 cm/sec, 87.2 cm/sec, and 3.49 for PSV, EDV, and PSVR, respectively. The degree of carotid artery stenosis for a subset of 124 vessels on CTA correlated well with that of DSA (ρ=0.89, P< 0.0001). These data demonstrate a high correlation between measurements obtained on CTA and DSA while forming reliable CTA-derived CDUS velocity criteria.

Potential of machine learning to predict early ischemic events after carotid endarterectomy or stenting: a comparison with surgeon predictions.

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are recommended for high stroke-risk patients with carotid artery stenosis to reduce ischemic events. However, we often face difficulty in determining the best treatment strategy. We aimed to develop an accurate post-CEA/CAS outcome prediction model using machine learning that will serve as a basis for a new decision support tool for patient-specific treatment planning. Retrospectively collected data from 165 consecutive patients with carotid stenosis underwent CEA or CAS and were divided into training and test samples. The following five machine learning algorithms were tuned, and their predictive performance was evaluated by comparison with surgeon predictions: an artificial neural network, logistic regression, support vector machine, random forest, and extreme gradient boosting (XGBoost). Seventeen clinical factors were introduced into the models. Outcome was defined as any ischemic stroke within 30days after treatment including asymptomatic diffusion-weighted imaging abnormalities. The XGBoost model performed the best in the evaluation; its sensitivity, specificity, positive predictive value, and accuracy were 31.9%, 94.6%, 47.2%, and 86.2%, respectively. These statistical measures were comparable to those of surgeons. Internal carotid artery peak systolic velocity, low-density lipoprotein cholesterol, and procedure (CEA or CAS) were the most contributing factors according to the XGBoost algorithm. We were able to develop a post-procedural outcome prediction model comparable to surgeons in performance. The accurate outcome prediction model will make it possible to make a more appropriate patient-specific selection of CEA or CAS for the treatment of carotid artery stenosis.

Simultaneous Multi-Vascular Bed Imaging in a Patient Supported by a Continuous-Flow LVAD

<h3>Introduction</h3> Patients supported with left ventricular assist devices (LVADs) are burdened by frequent hemocompatibility-related adverse events related to patient-pump interactions. These predominantly vascular events include stroke, gastrointestinal bleeding, and pump thrombosis. Our center performs routine, invasive hemodynamic ramp speed titrations in LVAD patients to determine the optimal rotational speed after implantation. We sought to interrogate changes in vascular hemodynamics during an exercise ramp study to understand the influence of pump speed and exercise on outflow graft and cerebrovascular flow. <h3>Case Report</h3> A 71-year-old male patient supported by Heartware HVAD operating at a baseline speed of 2700 RPM presented for LVAD ramp and exercise study with vascular imaging. A right heart catheterization, echocardiography with Doppler imaging of the patient's LVAD outflow graft, and vascular Doppler of the left common carotid artery and middle cerebral artery were performed. The patient's LVAD operating speed was reduced to 2400 RPM and then increased stepwise to a maximum speed of 3000 RPM. At each increment of operating speed, Doppler imaging was attempted and right heart catheterization was repeated. After reviewing data from the ramp study, the patient's operating speed was set to 2900 RPM and then a staged exercise protocol with bicycle ergometer was performed. Pertinent findings of vascular imaging include a blunting of peak systolic to end-diastolic velocity ratio in vascular beds with incremental speed increase and partial recovery of pulsatility with exercise (Figure). <h3>Summary</h3> This case demonstrates the influence LVAD speed adjustment and exercise have on carotid artery and outflow graft pulsatility. With exercise the outflow graft and carotid artery peak systolic and end-diastolic velocities were similar to those at the lowest LVAD pump speed, suggesting that intrinsic contractility and native LV unloading was restored with exercise despite a higher pump speed.

Respiratory Variation in Carotid Artery Peak Systolic Velocity Is Unable to Predict Fluid Responsiveness in Spontaneously Breathing Critically Ill Patients When Assessed by Novice Physician Sonologists.

Respiratory variation in carotid artery peak systolic velocity (ΔVpeak) assessed by point-of-care ultrasound (POCUS) has been proposed as a noninvasive means to predict fluid responsiveness. We aimed to evaluate the ability of carotid ΔVpeak as assessed by novice physician sonologists to predict fluid responsiveness. This study was conducted in 2 intensive care units. Spontaneously breathing, nonintubated patients with signs of volume depletion were included. Patients with atrial fibrillation/flutter, cardiogenic, obstructive or neurogenic shock, or those for whom further intravenous (IV) fluid administration would be harmful were excluded. Three novice physician sonologists were trained in POCUS assessment of carotid ΔVpeak. They assessed the carotid ΔVpeak in study participants prior to the administration of a 500 mL IV fluid bolus. Fluid responsiveness was defined as a ≥10% increase in cardiac index as measured using bioreactance. Eighty-six participants were enrolled, 50 (58.1%) were fluid responders. Carotid ΔVpeak performed poorly at predicting fluid responsiveness. Test characteristics for the optimum carotid ΔVpeak of 8.0% were: area under the receiver operating curve = 0.61 (95% CI: 0.48-0.73), sensitivity = 72.0% (95% CI: 58.3-82.56), specificity = 50.0% (95% CI: 34.5-65.5). Novice physician sonologists using POCUS are unable to predict fluid responsiveness using carotid ΔVpeak. Until further research identifies key limiting factors, clinicians should use caution directing IV fluid resuscitation using carotid ΔVpeak.

Variation in Ultrasound Diagnostic Thresholds for Carotid Stenosis in the United States

Individuals with carotid stenosis enter surveillance or are considered for surgery on the basis of disease severity assessed by ultrasound. However, there is variation in the ultrasound diagnostic thresholds used to determine disease severity. Our objective was to describe this variation and its potential impact on patients. To describe the variation in carotid ultrasound diagnostic thresholds, we examined testing protocols from 338 accredited vascular testing centers in the United States. To determine the potential impact of this variation, we applied the range of thresholds to carotid ultrasound parameters from 2 groups: a population-based sample ≥65 years of age in the Cardiovascular Health Study (n=4791), and a cohort of patients who underwent surgery for asymptomatic carotid stenosis in the Vascular Quality Initiative registry (n=28 483). Internal carotid artery peak systolic velocity was used by all centers to assess disease severity, with 60 distinct thresholds in use. The peak systolic velocity threshold for moderate (≥50%) stenosis ranged from 110 to 245 cm/s (median, 125; 5th and 95th percentile, 125 and 150), and the threshold for severe (≥70%) stenosis ranged from 175 to 340 cm/s (median, 230; 5th and 95th percentile, 230 and 275). In the population-based sample, the 5th percentile threshold would assign a diagnosis of moderate carotid stenosis to twice as many individuals as the 95th percentile threshold (7.9% versus 3.9%; relative risk, 2.01 [CI, 1.70-2.38]). In the surgical cohort, 1 in 10 (9.8%) patients had peak systolic velocity values that warranted the diagnosis of severe carotid stenosis at centers in the 5th percentile, but not in the 95th. The diagnostic threshold for carotid stenosis varies considerably. Whether or not a person is said to have moderate stenosis and enters surveillance, and whether or not they have severe stenosis and are candidates for surgery, can depend on which center performs their ultrasound.

CME Test for Internal to Common Carotid Artery Peak Systolic Velocity Ratios for Predicting North American Symptomatic Carotid Endarterectomy Trial Stenosis: Derivation/ Validation Study Using a Machine Learning Technique

CME Test for Internal to Common Carotid Artery Peak Systolic Velocity Ratios for Predicting North American Symptomatic Carotid Endarterectomy Trial Stenosis: Derivation/ Validation Study Using a Machine Learning Technique

Are systolic velocity duplex metrics negatively affected by flow aliasing in areas of critical internal carotid artery stenosis

ABSTRACTPurpose: Duplex scanning is a useful noninvasive screening tool for the detection of carotid bifurcation disease. Internal carotid artery (ICA) peak systolic velocity (PSV) and ICA/common carotid artery (CCA) PSV ratios are proven metrics determining 70%-99% ICA stenosis. A potential disadvantage of using dramatically increasing systolic velocity measurements in areas of critical arterial stenosis is flow aliasing. Diastolic velocity should be less influenced by this flow artifact. We evaluate ICA and CCA end diastolic velocity (EDV) metrics in predicting severe ICA stenosis and document the prevalence of an aliasing artifact in a population of patients with critical ICA stenosis.Methods: Consecutive patients undergoing carotid duplex assessments and contrast angiography were compared (n = 140). ICA and CCA PSV and EDV were recorded as was evidence of the flow aliasing of ICA waveforms. ICA/CCA PSV and EDV ratios were calculated. Duplex parameters were compared with angiographic ICA measurements. Receiver-operator characteristic curve (ROC) analysis was used to determine optimal criteria to identify ICA stenosis of 70% to 99%.Results: Of 256 carotid bifurcation duplex studies, critical angiographic stenosis was present in 105 arteries. Only four completed arterial duplex scans demonstrated flow aliasing. In three of these patients, systolic metrics were non-diagnostic versus ICA/CCA EDV ratios. An ICA/CCA EDV ratio of 2.3 provided the best combination of sensitivity 73.8% and specificity 75.18%.Conclusion: ICA/CCA diastolic ratios reliably determine 70% or greater ICA stenosis. Flow aliasing infrequently complicates ICA PSV.

Do Common Carotid Artery Velocities Consistently Decrease With Proximity to the Bifurcation?

Distal (near bifurcation) common carotid artery (CCA) peak systolic velocity (PSV) values are lower than near the origin (proximal). We investigate whether this applies to patients with internal carotid artery (ICA) stenosis ≥ 50% (PSV ≥ 125 cm/s). We studied 328 patients. We excluded carotid arteries with CCA stenosis and carotid endarterectomy. We evaluated degree of stenosis as absent, mild (1%-15%), moderate (16%-49%), and significant (≥50%; PSV ≥ 125 cm/s). We used paired t tests to compare the proximal with distal PSV values as a function of stenosis severity and analysis of variance for between stenosis differences. We studied 640 out of 656 bifurcations. Mean age was 68.9 (SD = 11.8) years, and 70% (228) men. Mean distal CCA PSV was 80.3 cm/s (SD = 23.1 cm/s) and proximal, 93.7 cm/s (SD = 26.6 cm/s). The difference between proximal and distal CCA PSV for ICA lesions &lt; 50% (n = 553; 14.8 ± 22.6 cm/s) was higher ( P = .004) than with an ICA stenosis ≥ 50% (n = 87; 4.6 ± 24.1 cm/s). While distal CCA PSV decreases in patients with absent/mild/moderate plaque, PSV velocities are more consistent along the length of the CCA with higher degrees of ICA stenosis. This might in part explain the reliability of the ICA/CCA velocity ratio for grading stenosis severity ≥50%.

Internal to Common Carotid Artery Peak Systolic Velocity Ratios for Predicting North American Symptomatic Carotid Endarterectomy Trial Stenosis: Derivation/Validation Study Using a Machine Learning Technique

The association between internal carotid artery/peak systolic velocity and stenosis severity as measured by the North American Symptomatic Carotid Endarterectomy Trial is known. The association of internal carotid artery peak systolic velocity to common carotid artery peak systolic velocity ratio is less well studied. We use a machine learning algorithm to study this association. We performed a meta-analysis of papers with point data showing graphs of internal carotid artery/peak systolic velocity ratio versus North American Symptomatic Carotid Endarterectomy Trial percent stenosis. We used a neural net algorithm to derive an equation relating internal carotid artery/common carotid artery peak systolic velocity to % stenosis in a derivation group (two thirds of the data points) and applied it to a validation subset (one third of the data points). Model performance was assessed by correlation coefficients and Bland-Altman analyses. We found 4 papers with appropriate data for a total of 775 data points. The mean % stenosis was 53% (26% SD) with a mean internal carotid artery/common carotid artery peak systolic velocity ratio of 3.9 (2.9 SD). The derivation data set (n = 516) showed an association with an r value of 0.76 ( P &lt; .0001) between predicted and measured stenosis. Applying the derived equation to the validation subset (n = 259) showed a similar association ( r = 0.8; P &lt; .0001). A machine learning algorithm gave a good approximation of the association between internal carotid artery/common carotid artery peak systolic velocity ratio and % stenosis on a continuous scale for the aggregate data of 4 published studies. These data could be used to study the accuracy of different cut-points for 50% and 70% stenosis in an unbiased fashion.

The incidence of carotid in-stent stenosis is underestimated ≥50% or ≥80% and its clinical implications

BackgroundThe incidence of carotid in-stent stenosis has been reported to vary between 1% and 30%. Most published studies have short follow-up, which may lead to underestimation of the incidence of in-stent stenosis. This study analyzed the incidence of ≥50% and ≥80% in-stent stenosis using validated duplex ultrasound criteria and its clinical implications. MethodsThis is a retrospective analysis of prospectively collected data of 450 carotid artery stenting (CAS) procedures (February 6, 2001-December 19, 2016). All patients had postoperative carotid duplex ultrasound examination, which was repeated at 1 month, 6 months, and every 6 to 12 months thereafter. A Kaplan-Meier analysis was used to estimate rates of freedom from ≥50% in-stent stenosis (internal carotid artery peak systolic velocity of ≥224 cm/s) and ≥80% in-stent stenosis (internal carotid artery peak systolic velocity of ≥325 cm/s), freedom from reintervention, and survival. ResultsThe mean age was 68.3 years, with a mean follow-up of 40.3 months. A total of 201 patients (45% [201/450]) had CAS for symptomatic disease. Primary CAS was done in 291 patients (65%); in the remaining 35%, CAS was done for postcarotid endarterectomy (CEA) stenosis. A total of 101 patients (23%) had ≥50% late carotid in-stent stenosis, and of these, 33 (7.4%) had ≥80% in-stent stenosis. Nineteen patients (4.3%) developed late transient ischemic attack and three (0.7%) late stroke. Twenty-three (5.2%) patients had late reintervention. Rates of freedom from ≥50% in-stent stenosis in the whole series were 85%, 79%, 75%, 72%, and 70% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively. The rates of freedom from ≥50% in-stent stenosis for primary CAS and CAS for post-CEA stenosis were not statistically significant (P = .540). The rates of freedom from ≥80% in-stent stenosis for the whole series were 96%, 95%, 93%, 90%, and 89% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively. The rates of freedom from ≥80% in-stent stenosis for primary CAS and CAS for post-CEA stenosis were also not statistically significant (P = .516). Rates of freedom from reintervention were 98%, 96%, 93%, 93%, and 91% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively, and there were no significant differences between primary CAS and CAS for post-CEA stenosis (P = .939). The overall late survival rates were 99%, 97%, 96%, 94%, and 91% at 1 year, 2 years, 3 years, 4 years, and 5 years. ConclusionsThe incidence of ≥50% in-stent stenosis is relatively high; however, the rates of ≥80% stenosis and late neurologic events are low. Longer follow-up of patients with ≥50% carotid in-stent stenosis may yield higher incidence of ≥80% stenosis.

RS07. The Incidence of Carotid In-Stent Stenosis Is Underestimated: Is It 50% or 80% and Its Clinical Implications

The incidence of carotid in-stent stenosis has been reported to vary between 1% and 30%. Most published studies have relatively short follow-up periods, which may lead to underestimating the incidence of carotid in-stent stenosis rates. This study analyzed the incidence of 50% and 80% carotid in-stent restenosis using validated duplex velocity criteria and its clinical implications. This retrospective analysis included prospectively collected data from 450 carotid artery stent (CAS) procedures. All patients had postoperative carotid duplex ultrasound examination, which was repeated at 1 month, 6 months, and every 6 to 12 months thereafter. A Kaplan-Meier analysis was used to estimate the freedom rates from 50% in-stent restenosis (internal carotid artery peak systolic velocity of 224 cm/s) and 80% in-stent restenosis (internal carotid artery peak systolic velocity of 325 cm/s) and its clinical implications. The mean age was 68.3 years, with a mean follow-up of 40.3 months. A total of 201 of 450 patients (45%) underwent CAS for symptomatic disease. Primary CAS was done in 291 patients (65%) and the remaining 35% were done for post-CEA stenosis. A total of 101 patients (23%) had 50% late carotid in-stent restenosis, and of these, 33 (7.4%) had 80% in-stent restenosis. Nineteen patients (4.3%) developed late transient ischemic attack and three (0.7%) late stroke. Twenty-three (5.2%) patients had late reintervention. Rates of freedom from 50% in-stent restenosis in the whole series were 85%, 79%, 75%, 72%, and 70% at 1, 2, 3, 4, and 5 years, respectively (Fig 1). The rates of freedom from 50% in-stent restenosis for primary CAS and CAS for post-CEA restenosis were not statistically significant (P = .540). The rates of freedom from 80% in-stent restenosis for the whole series were 96%, 95%, 93%, 90%, and 89% at 1, 2, 3, 4, and 5 years, respectively (Fig 2). The rates of freedom from 80% in-stent restenosis for primary CAS and CAS for post-CEA restenosis, were also not significant (P = .516). The rates of freedom from reintervention were 98%, 96%, 93%, 93%, and 91% at 1, 2, 3, 4, and 5 years, respectively, and there were no differences between primary CAS and CAS for post-CEA stenosis (P = .939). The overall late survival rates were 99%, 97%, 96%, 94%, and 91% at 1, 2, 3, 4, and 5 years, respectively. The incidence of 50% in-stent restenosis is relatively high; however, the rates of 80% restenosis and late neurologic events are low.Fig 2Freedom from >80% restenosis.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

12주간 복합운동이 비만 성인여성의 경동맥 순응도 및 수축기 혈류속도와 내경 비에 미치는 영향

12주간 복합운동이 비만 성인여성의 경동맥 순응도 및 수축기 혈류속도와 내경 비에 미치는 영향