Diagnosis Of Carotid Stenosis Research Articles

Impact of carotid stenosis on the outcome of stroke patients submitted to reperfusion treatments: a narrative review.

Intravenous thrombolysis (IT) and mechanical thrombectomy (MD) are the two interventional approaches that have changed the outcome of patients with acute ischemic stroke (AIS). Ipsilateral and contralateral carotid stenosis (ICS, CCS) play an important role in regulating cerebral hemodynamics, both in chronic and acute situations such as AIS. Several studies have explored their role in the incidence and severity of stroke, but very few have investigated the possible impact of ICS and CCS on the efficacy of interventional procedures. The purpose of this review was to I) highlight the incidence and prevalence of carotid stenosis (CS); II) assess the impact of ICS and CCS on cerebral hemodynamics; III) evaluate the effect of carotid stenosis on the efficacy of interventional therapies (IT and MT) for AIS; and IV) report therapeutic complications related to CS. We searched PubMed/Medline for case reports, reviews, and original research articles on English-language review topics during the period from January 1, 2000 to October 1, 2023. CS is associated with 15-20 % of the total number of AIS. ICS and CCS had a negative influence on both cerebral hemodynamics before AIS and outcome after interventional procedures (IT, MT alone or in bridging). Available data on cerebral hemodynamics and efficacy of interventional therapies for AIS suggest a negative role of CS. Therefore, early diagnosis of CS may be considered relevant to preventive and post-stroke treatment strategies.

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.

Analysis of the value of dual-energy CT angiography in the diagnosis of carotid stenosis and plaque.

Analysis of the value of dual-energy CT angiography in the diagnosis of carotid stenosis and plaque.

Early Diagnosis of Carotid Stenosis by Ultrasound Doppler Investigations: A Classification Method for the Hemodynamic Parameter

Pulsed Wave Doppler (PWD) is a traditional ultrasound technique used for the diagnosis of cardiovascular disease. The conventional diagnostic method is based on hemodynamic parameters obtained from the PW spectrum. However, it relies on the clinical experience of sonographers, and especially focusing on severe carotid stenosis. This paper proposes a classification method for the hemodynamic parameter using the RUSBoost algorithm. The proposed method improves the performance of RUSBoost by setting the empirical weight of each sample. The experimental results show that the proposed method reaches the accuracy of 90.1%, the sensitivity of 70%, and the specificity of 94%, which are 4%, 6%, and 2% higher than the original RUSBoost respectively. In addition, the proposed method is objective, since the empirical weights are computed based on Mahalanobis distance without any expert input. It can be used for the early detection of cardiovascular disease.

Why are we still debating criteria for carotid artery stenosis?

The risk of new or recurrent stroke is high among patients with extracranial carotid artery stenosis and the benefit of carotid revascularization is associated to the degree of luminal stenosis. Catheter-based digital subtraction angiography (DSA) as the diagnostic gold-standard for carotid stenosis (CS) has been replaced by non-invasive techniques including duplex ultrasound, computed-tomography angiography, and magnetic resonance angiography (MRA). Duplex ultrasound is the primary noninvasive diagnostic tool for detecting, grading and monitoring of carotid artery stenosis due to its low cost, high resolution, and widespread availability. However, as discussed in this review, there is a wide range of practice patterns in use of ultrasound diagnostic criteria for carotid artery stenosis. To date, there is no internationally accepted standard for the gradation of CS. Discrepancies in ultrasound criteria may result in clinically relevant misclassification of disease severity leading to inappropriate referral, or lack of it, to revascularization procedures, and potential for consequential adverse outcome. The Society of Radiologists in Ultrasound (SRU), either as originally outlined or in a modified form, are the most common criteria applied. However, such criteria have received criticism for relying primarily on peak systolic velocities, a parameter that when used in isolation could be misleading. Recent proposals rely on a multiparametric approach in which the hemodynamic consequences of carotid narrowing beyond velocity augmentation are considered for an accurate stenosis classification. Consensus criteria would provide standardized parameters for the diagnosis of CS and considerably improve quality of care. Accrediting bodies around the world have called for consensus on unified criteria for diagnosis of CS. A healthy debate between professionals caring for patients with CS regarding optimal CS criteria still continues.

THE ROLE OF THE ULTRASOUND DOPPLEROGRAPHY IN THE DIAGNOSIS OF ARTERIAL OBSTRUCTION

One of the priority areas of neurology is cerebrovascular disease. Vascular diseases of the central nervous system have a great importance, being the cause of mortality and disability, and from year to year there is an increase in these indicators. For this reason, the timely organization of the diagnosis of cerebrovascular diseases plays an important role for their prevention and treatment. In the diagnosis of carotid stenosis, which is a risk factor for strokes, the role of ultrasound dopplerography, combining the identification of these factors, determining the mechanisms for the development of stroke, conducting therapeutic, surgical screening, catheterization, and monitoring of injured arteries, is quite high. The presented article is devoted to the role of ultrasound dopplerography in the diagnosis of arterial obstruction.

CAR 5. Carotid Flow Volume Measurement in Doppler Ultrasound as a New Look at the Diagnosis of Internal Carotid Artery Stenosis

Blood flow velocity criteria in the diagnosis of carotid stenosis are well defined; however, there are no reference values concerning blood flow volume. The objective of this work covered assessment of blood flow volume in the internal carotid artery (ICA), external carotid artery (ECA), and vertebral artery (VA) in healthy volunteers and asymptomatic patients with carotid artery disease older than 65 years with the aim of implementation of blood flow volume measurements in clinical assessment of patients with carotid artery disease. There were 303 patients without history of neurologic symptoms included in the examination. The group of 123 healthy volunteers older than 65 years, without comorbidities that may alter cerebral blood flow volume, were examined to determine reference flow volume values in the ICA, ECA, and VA. The flow parameters in this group were compared with the flow in 56 healthy volunteers younger than 65 years. To determine the influence of ICA stenosis on cerebral blood flow volume, the group of 124 patients older than 65 years with asymptomatic ICA stenosis without comorbidities that might influence hemodynamics of blood flow were examined. In all patients, an extensive Doppler ultrasound examination with measurement of blood flow volume in the ICA, ECA, and VA was performed. Cerebral blood flow volume reference values in patients older than 65 years were determined. Gradual decline in cerebral blood flow, caused mainly by the significant reduction of ICA flow volume, was observed in healthy volunteers. A decline in the peak systolic and end-diastolic velocities in the ICA and the peak systolic velocity in the ECA was observed. Two subgroups with ICA stenosis and flow volume changes were identified: patients with compensatory elevation of blood flow volume and those without compensation whose flow volume was lower than reference values. The latter subgroup contained mainly patients with >50% ICA stenosis. Among asymptomatic patients with significant ICA stenosis, there is a subgroup without compensatory elevation of blood flow volume. Those patients may be more vulnerable to cerebral ischemia and featured with increased risk of ischemic stroke.

Monocyte/lymphocyte ratio is associated with carotid stenosis in ischemic stroke: A retrospective analysis.

BackgroundCarotid artery stenosis, mainly caused by carotid atherosclerosis, is related to ischemic stroke. This study was to investigate whether monocyte/lymphocyte ratio (MLR) was associated with increased severity of carotid stenosis in patients with ischemic stroke.MethodsA total of 395 participants with ischemic stroke were retrospectively analyzed. The severity of carotid stenosis was evaluated by ultrasound examination. Patients were divided into two groups: nonsevere stenosis group and severe stenosis group. Multivariate logistic analysis was used to evaluate risk factors.ResultsA significant correlation was found between MLR and the severity of carotid stenosis in patients with ischemic stroke. MLR was the independent risk factor of carotid stenosis (OR: 9.74, 95% CI: 1.16–81.54). In the ROC curves analysis, a cutoff value of 0.20 for MLR predicted the severity of carotid stenosis with a sensitivity of 80.40% and specificity of 26.40% (ROC area under the curve: 0.598, 95% CI: 0.53–0.67, p = .004).ConclusionMonocyte/lymphocyte ratio plays important roles in carotid stenosis in patients with ischemic stroke and is an independent risk factor of the severity of carotid stenosis. Therefore, MLR might be considered a potential index in the diagnosis of carotid stenosis in patients with ischemic stroke.

Regional frequency variation of revascularization procedures for carotid stenosis in Germany: Secondary data analysis of DRG data from 2012 to 2014.

BackgroundFor Germany, regional variation of procedure rates of carotid endarterectomy (CEA) and carotid artery stenting (CAS) performed for carotid stenosis have so far not been analyzed at a national level. The aim of this study was to assess small area estimates of procedure rates among German regions, and to identify regional characteristics, which are associated with the regional frequency of procedures.MethodsGerman diagnosis-related groups (DRG) statistics (2012–2014) were analyzed. Inclusion and exclusion criteria for procedural codes were set according to German quality assurance measures in combination with the diagnosis of carotid stenosis (I65.2). Rates of CEA and CAS were indirectly standardized for sex and age.ResultsIn total, 88,182 procedures were performed (73,042 CEA; 15,367 CAS). The overall procedure rate varied between 13.2 per 100,000 (Augsburg) and 89.2 per 100,000 (Wilhelmshaven). Spatial analysis revealed that regional distribution was significantly clustered.ConclusionThe rates of CEA, and especially of CAS showed high regional variation. The spatial distribution was significantly clustered. In addition to the regional prevalence of diabetes mellitus, smoking and obesity, socioeconomic factors, such as income and debts were correlated with the overall frequency of CEA and CAS. No significant association was found between indicators of health infrastructure (e. g. density of hospital beds, vascular surgeons and angiologists) and the overall procedure rate.Electronic supplementary materialThe online version of this article (10.1007/s00772-018-0415-7) includes further information on study limitations, as well as additional tables and figures. The article and supplementary material are available at http://www.springermedizin.de/gefaesschirurgie. The additional material can be found at the end of the article under “supplementary material”.

Comparative analysis of 3D time-resolved contrast-enhanced magnetic resonance angiography, color Doppler ultrasound and digital subtraction angiography in symptomatic carotid stenosis.

The present study aimed to compare the diagnostic value of contrast-enhanced magnetic resonance angiography (CE MRA) with 3D time-resolved imaging of contrast kinetics, color Doppler ultrasound (CDUS) and digital subtraction angiography (DSA) in extracranial carotid stenosis (CS). A total of 54 patients with symptomatic CS were subjected to CDUS, CE MRA and DSA examination. Results of DSA were defined as the standard, and a total of 216 vessels were examined. In each patient four vessels were examined, namely the bilateral common carotid arteries and the bilateral internal carotid arteries. The sensitivities and specificities of CE MRA and CDUS for various degrees of CS were also determined. It was observed that the sensitivities to mild-level (1-49%), moderate-level (50-69%) and severe-level (70-99%) CS were 85.45, 100 and 100% for CE MRA, and 78.18, 50 and 100% for CDUS, respectively. The corresponding specificities were 95.27, 98.58 and 99.53% for CE MRA, and 79.05, 93.36 and 98.10% for CDUS, respectively. In addition, the carotid sinus plaque detection rate for CDUS was significantly higher than that of DSA and CE MRA (both P<0.001). Detection rates for common carotid artery plaques and internal carotid artery plaques did not significantly differ among the three examination methods (all P>0.05). These data demonstrate that CE MRA has higher sensitivity and specificity than CDUS for the diagnosis of CS, and that CDUS has a higher carotid sinus plaque detection rate than DSA and CE MRA. Therefore, the combination of MRI and CDUS may be a 'gold standard' diagnostic method for the detection of moderate and severe CS.

Cerebral Hemodynamics in Carotid or Intracranial Disease

A hemodynamically significant stenosis in the carotid artery constitutes an important cause of ischemic stroke. Carotid stenosis, especially when symptomatic, carries a high risk of stroke recurrence despite the best medical therapy. The presentation would include the role of cerebrovascular ultrasonography in the diagnosis of carotid stenosis. Various advanced applications of neurosonology enable the grading of severity, risk-stratification as well as monitoring the natural course of carotid stenosis. Intracranial stenosis is an important cause of cerebrovascular ischemia, especially among stroke patients of Asian ancestory. Up to 50% of Asian patients with acute ischemic stroke may harbour intracranial atherosclerotic disease. This talk would discuss the role of transcranial Doppler (TCD) in the diagnosis and assessment of the severity of intracranial stenosis. Furthermore, advanced applications of TCD may help in optimizing the best medical therapy as well as identifying patients eligible for various interventional procedures.

Stroke associated with coronary artery bypass grafting.

While coronary artery bypass grafting (CABG) has been playing a significant role in the revascularization for ischemic heart disease, neurological complications associated with CABG have been a primary concern. Stroke, although the incidence is low, is one of the most devastating complication of CABG. Many studies have identified the risk factors for stroke with CABG, such as prior stroke, carotid artery stenosis, aortic atherosclerosis, atrial fibrillation and cardiopulmonary bypass. Various rational approaches focusing on individual risk factor have been proposed for the stroke. Prophylactic carotid revascularization is an important strategy, and the diagnosis of carotid stenosis has to be established correctly. Prevention of emboli from aortic plaque is also an essential issue. Intraoperative monitoring with transesophageal or epiaortic ultrasound is useful to identify mobile atheromatous plaques and to select appropriate aortic manipulations. Maintenance of cerebral blood flow and blood pressure during cardiopulmonary bypass might be critical issues. Besides, there are conflicting two opinions regarding off-pump CABG; one supports an efficiency for the prevention of stroke while the other advocates no effect. This discrepancy might be explained by the difference of the risk of stroke in the population of the individual study and by the variation of the percentage of aortic clamping or aortic anastomosis in each study. Pharmaceutical therapies such as statin, preventive medication for atrial fibrillation, or antiplatelet are promising methods. Although it is hard to decrease the incidence of the stroke with any single countermeasure, sustained effort should be continued to overcome the stroke associated with CABG.

Discrepancy Between Duplex Sonography and Digital Subtraction Angiography When Investigating Extra- and Intracranial Ulcerated Plaque

Noninvasive color-coded duplex sonography has become a good, convenient, and reproducible screening tool for the general population when studying cerebral hemodynamics and atherosclerotic disease. Digital subtraction angiography (DSA) is still the gold standard for the diagnosis of carotid stenosis, although other noninvasive imaging tools are also available. At present, ultrasound scanning, followed by confirmatory DSA, is a cost-effective way to survey patients suspected of suffering from cerebral arterial stenosis. We report two patients who had cerebral ischemic symptoms due to high-grade stenosis of either the cervical internal carotid artery (ICA) or the middle cerebral artery (MCA), combined with an ulcerated plaque. Ultrasonographic Doppler analysis identified high-grade stenotic lesions as marked elevations in the turbulent flow of the cervical ICA in one patient and of the middle cerebral artery in the other patient. Subsequently, huge plaque ulceration was found by color B-mode scanning of the patient with cervical ICA stenosis. However, DSA was able to demonstrate only a mild–moderate degree of stenosis associated with the lesions. High-grade stenotic lesions of the ICA and the middle cerebral artery were reconfirmed by computed tomography angiography and magnetic resonance angiography. An atheromatous plaque with ulceration is believed to be the cause of this discrepancy between ultrasonography and DSA.

Carotid Stenosis: An Update on Early Outcomes Comparing Carotid Endarterectomy and Carotid Artery Stenting

Objectives: To compare the results of carotid endarterectomy (CEA) and carotid stenting (CAS) of patients with carotid stenosis in Nationwide Inpatient Sample (NIS) of the Healthcare Cost and Utilization Project (HCUP) from 2008 through 2010. Methods: An analysis of approximately 8 million annual hospital admissions from 2008 to 2010 was obtained from the HCUP NIS database. Using ICD9 coding, we selected patients with the diagnosis of carotid stenosis and then created subsets of patients that underwent CEA vs CAS. The study focused on early outcomes, including stroke, myocardial infarction (MI), and in-hospital mortality. 2 Tests and t tests were used to confirm statistical significance if P .05. Results: A total of 276,043 patients were admitted with the diagnosis of carotid stenosis from 2008 to 2010, representing an estimated 1.38 million admissions. Average age of CEA and CAS patients was 71.02 9.53 and 70.64 10.08 years (P .000). After weighted adjustment, 328,756 patients underwent CEA and 47,813 patients underwent CAS annually in the United States. Postoperative stroke rate for CEA vs CAS was 1.0% vs 2.1% (odds ratio [OR], 2.07; 95% confidence interval {CI], 1.93-2.23, P .000). Postoperative stroke by individual year for CEA vs CAS was 1.0% vs 2.1% for 2008, 1.1% vs 2.3% for 2009, and 1.0% vs 2.1% for 2010. In-hospital mortality for CEA vs CAS was 0.4% vs 1.0% (OR, 2.58; 95% CI, 2.32-2.87, P .000). Mortality rates for CEA vs CAS by year were 0.4% vs 1.8% for 2008, 0.5% vs 1.9% for 2009, and 0.3% vs 2.1% for 2010. Postoperative MI for CEA vs CAS was 1.4% vs 1.9% (OR, 1.33; 95% CI, 1.24-1.44; P .000). Postoperative rates of MI for CEA vs CAS by year were 1.5% vs 1.7%, for 2008, 1.6% vs 2.1% for 2009, and 1.2% vs 2.0% for 2010 (Table).

Management of Symptomatic Carotid Stenosis in Individuals with CKD

Despite recent interest in carotid stenting for treatment of carotid stenosis, carotid endarterectomy remains the standard of care, particularly for individuals with symptoms referable to that carotid and with moderate to severe stenosis. Interest in stenting has increased in individuals with more medical comorbidities, including renal disease, despite lack of clear data contraindicating endarterectomy in these patients. The article by Mathew et al. in this issue of JASN 1 analyzes existing data from the North American Symptomatic Carotid Endarterectomy trial (NASCET),2 the only large randomized carotid endarterectomy trial in which creatinine levels were routinely measured. The authors show that carotid endarterectomy not only may benefit individuals with symptomatic carotid stenosis and chronic kidney disease (CKD) but also is safe and without major operative complications. In their analysis, the number needed to treat to prevent one stroke among individuals with CKD was only four, compared with 10 among individuals without CKD. The primary reason for the results in this article, strongly supportive of carotid endarterectomy in symptomatic patients, is that individuals who have GFR <30 ml/min per 1.73 m2 with symptomatic high-grade carotid stenosis (≥70%) and are treated medically have much higher rates of stroke, myocardial infarction, or death than do their equivalents with a normal …

Prevalence of carotid artery disease in an ischemic stroke population: role of Doppler ultrasonography

Atherosclerotic carotid disease represents approximately 20% of the causes of ischemic stroke. Effective treatment options, such as endovascular or surgical revascularization procedures, are available. Doppler Ultrasound (DUS) is a non-invasive, inexpensive, routine exam used to evaluate the presence of internal carotid artery (ICA) stenosis. We retrospectively analysed the prevalence of severe atherosclerotic carotid disease in a population of patients with acute ischemic stroke/transitory ischemic attacks (TIAs), and the role of DUS in the detection of ICA stenosis and treatment decisions in these patients. A total of 318 patients with ischemic stroke or TIAs was admitted to our stroke unit, and 260 patients were studied by DUS. ICA stenosis was evaluated by DUS according to peak systolic velocity. All DUS exams were performed by the same operator. ICA stenosis was further assessed in 43 patients by digital subtraction angiography (DSA) using NASCET criteria. Of the total 318 patients, 260 (82%) had DUS evaluation. Of the total 520 ICAs studied by DUS, degrees of ICA stenosis were: 0-29% n= 438 (84%); 30-49% n= 8 (2%); 50-69% n= 27 (5%); 70-89% n= 15 (3%); 90-99% n= 20 (4%); oclusão n= 14 (2%). Of the total 260 patients studied, 43 (16.5%) underwent DSA. Sensibility and specificity of DUS in the diagnosis of carotid stenosis over 70% were, respectively, 91% e 84%. Of the total 31 patients with significant carotid stenosis (70-99%), 23 (74%) underwent subsequent carotid revascularization procedures. DUS is an important screening test in our stroke unit, justifying its use as a routine exam for all patients with ischemic stroke/TIAs. Moreover, our results show the relevance of severe carotid disease in a population with acute ischemic stroke/TIAs (16.5%), with a total of 9% of patients being submitted to carotid revascularization procedures.

Duplex Scan Evaluation of Carotid Stenosis. Which Consensus is Necessary?

During the past several years Carotid ultrasound has assumed an even greater role in the diagnosis of carotid stenosis and has been adopted as the first line preoperative test. It is advisable that each ultrasound laboratory should undertake regular validated comparisons between Duplex and angiography before systematic Duplex practice, especially when new machines or technologists arrive. Unfortunately, there is no general consensus on what constitutes the exact gold-standard for Duplex evaluation. This has been evidenced by the survey described in the article of Walker and Naylor published in this number of EJVES. 1 The Authors sent a questionnaire to assess which Duplex criteria were most commonly used to define carotid stenosis among members of the Society of Vascular Technology of Great Britain and Ireland: astonishingly, the majority of technologists did not know which measurements method was used in their unit. Furthermore, despite both the above countries were the largest contributors to ECST, most of the responders were using criteria that were more consistent with a NASCET than an ECSTclassification. In the face of redefinition of indications for carotid revascularization, the attempt to identify which Duplex criteria are mostly employed should be appreciated and the use of a questionnaire is a valuable tool. The paper of Walker and Naylor confirms the value that Audits and, to a larger extent, well conducted Registries may have in providing useful information. The most important messages provided by the above paper can be summarized as follows: (1) Despite several papers published shortly after the NASCETand ECSTresults questioned the safety of performing CEAwithout diagnostic angiography, 2 other studies, including the survey of Walker and Naylor, 1 have shown that the use of ultrasound as the sole imaging techniques to establish the indication for CEA has worldwide replaced the utilization of other more expensive and risky technologies without detriment for patients outcome. This practice, in the attempt to decrease invasiveness and complications of carotid revascularization, has occurred in face of lack of evidence-based data supporting this switching of technologies. The issue may be even more important in the perspective of comparing CEA with carotid stenting (CAS), if and when, after the necessary randomized trials, CAS will be confirmed as an alternative or even substitute for CEA.

Noninvasive Assessment of Spontaneous Baroreflex Sensitivity and Heart Rate Variability in Patients with Carotid Stenosis

Background: Previous limited observations have suggested that atherosclerosis may affect the distensibility of the carotid sinus and then impair the baroreflex sensitivity (BRS). No studies have been done to compare the BRS and heart rate variability (HRV) in patients with carotid stenosis and normal controls. Methods: A convenience-consecutive sample of 118 patients with transient ischemic attack or minor stroke 3 months to 1 year before (mean 6 months) who met the study criteria were referred to the neurovascular laboratory of the study hospital. Forty-three age-matched healthy adults were recruited as the normal controls. The inclusion criteria for participation were (1) no diabetes mellitus, (2) no history, symptoms or ECG signs of coronary artery disease or myocardial infarction, and (3) presence of carotid stenosis greater than or equal to 50%. The diagnosis of carotid stenosis was made using color-coded duplex ultrasound with published criteria. We categorized the patients into two groups: group 1 had moderate stenosis (50–75%) and group 2 had high-grade stenosis (75–99%). Instantaneous systolic blood pressure (SBP) and heart rate of all participants were assessed noninvasively using servo-controlled infrared finger plethysmography. The fluctuation in SBP as well as the interpulse interval (IPI) was divided into three components at specific frequency ranges by fast Fourier transform as high frequency (HF; 0.15–0.4 Hz), low frequency (LF; 0.04–0.15 Hz) and very low frequency (VLF; 0.004–0.04 Hz). The BRS was expressed as (1) transfer function with its magnitude in the HF and LF ranges, (2) BRS index alpha, and (3) regression coefficient by sequence analysis. The HRV was expressed as total power and power in the three frequency ranges (HF, LF and VLF). Results: The final analysis included 99 patients (mean age 72 ± 6 years, 79 male) and 43 healthy controls (mean age 68 ± 7 years, 30 male). Forty-three patients were classified as group 1 (stenosis 50–75%) and 56 as group 2 (stenosis 75–99%). There was no significant difference in the IPI between patients and controls (p value = 0.8637). We observed a significant decrease in all three HRV components (VLF, LF and HF) in the patients; however, there were no differences between the two patient groups with various degrees of stenosis. All the indices of BRS, including the magnitude of SBP-IPI transfer function at LF and HF, the computed BRS index alpha and the regression coefficient of sequence analysis, revealed similar results. Patients exhibited a significant reduction in the BRS (p < 0.001) compared with controls, and no difference was found between the two groups of patients. Conclusions: Our study linked significant carotid stenosis to two important autonomic markers (BRS and HRV) that may have prognostic value for patients with cardiovascular events. Further prospective studies are needed to explore whether or not the decreased BRS and HRV can be predictors for poor cardiovascular prognosis, or even for shortened life span in general, in patients with significant carotid stenosis.

Preoperative Diagnosis of Carotid Stenosis by Noninvasive Testing

Catheter-based angiography commonly is used to determine whether patients with TIAs or minor strokes have symptomatic 50%-99% stenosis of the internal carotid artery (ICA) and thus could clearly benefit from endarterectomy. However, because catheter-based angiography can cause stroke and death, these researchers prospectively compared the accuracy of digital subtraction angiography (DSA) with that of two noninvasive techniques in 350 patients with suspected symptomatic ICA disease. Carotid ultrasound (CUS) was used in 313 cases, magnetic resonance angiography …

Duplex scanning and CT angiography in the diagnosis of carotid artery occlusion: a prospective study

Differentiating total occlusion from tight stenosis of the internal carotid artery is crucial with regard to treatment and prognosis. At our institution, the diagnosis of carotid stenosis is based on duplex scanning. In cases of occlusion, duplex is not reliable, and angiography is performed, thereby increasing morbidity. We tried to determine whether a combination of duplex scanning and CT angiography (CTA) can replace angiography in the diagnosis of carotid occlusion. Prospective study. From 1995 to 1997, 148 patients were diagnosed as having carotid occlusion by duplex scanning. CTA was performed on all patients. Forty-four patients underwent angiography and 10 patients were surgically explored. Both procedures were considered "gold standard" for the diagnosis of occlusion. Arteries found to be occluded by both CTA and duplex scan were confirmed as occluded by angiography or operation in 95% of the cases (42/44). Arteries found to be occluded by duplex but patent by CTA were confirmed as patent in 100% of cases (10/10). CTA has a significantly higher positive predicting value for diagnosing occlusion than duplex scan (95% vs. 77%, p value < 0.01). Combination of duplex scanning and CTA is safe and accurate in the diagnosis of carotid occlusion and can replace angiography in most cases, thereby reducing morbidity.