Routine preoperative carotid duplex scanning in patients undergoing open heart surgery: is it worthwhile?

A Systematic Review Supporting the Society for Vascular Surgery Guidelines on the Management of Carotid Artery Disease

BACKGROUND

To support the development of guidelines on the management of carotid disease, a writing committee from the Society for Vascular Surgery has commissioned this systematic review.

METHODS

We searched multiple data bases for studies addressing 5 questions: medical management vs. carotid revascularization (CEA) in asymptomatic patients, CEA vs. CAS in symptomatic low surgical risk patients, the optimal timing of revascularization after acute stroke, screening high risk patients for carotid disease, and the optimal sequence of interventions in patients with combined coronary and carotid disease. Studies were selected and appraised by pairs of independent reviewers. Meta-analyses were performed when feasible.

RESULTS

Medical management compared to carotid interventions in asymptomatic patients was associated with better early outcome during the first 30 days. However, CEA was associated with significantly lower long-term rate of stroke/death at 5 years. In symptomatic low risk surgical patients, CEA was associated with lower risk of stroke, but a significant increase in MI compared to CAS during the first 30 days. When the long-term outcome of transfemoral CAS vs. CEA in symptomatic patients were examined using pre-planned pooled analysis of individual patient data from four randomized trials, the risk of death or stroke within 120 days of the index procedure was 5.5% for CEA and 8.7% for CAS, which lends support that over the long-term, CEA has superior outcome than transfemoral CAS. When managing acute stroke, the comparison of CEA during the first 48 hours to that between day 2 and day14 did not reveal a statistically significant difference on outcomes during the first 30 days. Registry data show good results with CEA performed in the first week, but not within the first 48 hours. A single risk factor, aside from PAD, was associated with low carotid screening yield. Multiple risk factors greatly increase the yield of screening. Evidence on the timing of interventions in patients with combined carotid and coronary disease was sparse and imprecise. Patients without carotid symptoms, who had the carotid intervention first, compared to a combined carotid intervention and CABG, had better outcomes.

CONCLUSIONS

This updated evidence summary will support the SVS clinical practice guidelines for commonly raised clinical scenarios. CEA was superior to medical therapy in long-term prevention of stroke/death over medical therapy. CEA was also superior to transfemoral CAS in minimizing long-term stroke/death for symptomatic low risk surgical patients. CEA should optimally be performed between 2-14 days from the onset of acute stroke. Having multiple risk factors increases the value of carotid screening.

SOCIETY FOR VASCULAR SURGERY CLINICAL PRACTICE GUIDELINES FOR MANAGEMENT OF EXTRACRANIAL CEREBROVASCULAR DISEASE

Management of carotid bifurcation stenosis in stroke prevention has been the subject of extensive investigations, including multiple randomized controlled trials. The proper treatment of patients with carotid bifurcation disease is of major interest to vascular surgeons and other vascular specialists. In 2011, the Society for Vascular Surgery published guidelines for treatment of carotid artery disease. At the time, several randomized trials, comparing carotid endarterectomy (CEA) and carotid artery stenting (CAS), were published. Since that publication, several studies and a few systematic reviews comparing CEA and CAS have been published, and the role of medical management has been re-emphasized. The current publication updates and expands the 2011 guidelines with specific emphasis on five areas: is carotid endarterectomy recommended over maximal medical therapy in low risk patients; is carotid endarterectomy recommended over trans-femoral carotid artery stenting in low surgical risk patients with symptomatic carotid artery stenosis of >50%; timing of carotid Intervention in patients presenting with acute stroke; screening for carotid artery stenosis in asymptomatic patients; and optimal sequence for intervention in patients with combined carotid and coronary artery disease. A separate implementation document will address other important clinical issues in extracranial cerebrovascular disease. Recommendations are made using the GRADE (Grades of Recommendation Assessment, Development and Evaluation) approach, as has been done with other Society for Vascular Surgery guidelines. The committee recommends CEA as the first-line treatment for symptomatic low risk surgical patients with stenosis of 50% to 99% and asymptomatic patients with stenosis of 70% to 99%. The perioperative risk of stroke and death in asymptomatic patients must be <3% to ensure benefit for the patient. In patients with recent stable stroke (modified Rankin 0-2), carotid revascularization is considered appropriate in symptomatic patients with greater than 50% stenosis and is recommended and performed as soon as the patient is neurologically stable after 48 hours but definitely before 14 days of onset of symptoms. In the general population, screening for clinically asymptomatic carotid artery stenosis in patients without cerebrovascular symptoms or significant risk factors for carotid artery disease is not recommended. In selected asymptomatic patients who are at increased risk for carotid stenosis, we suggest screening for clinically asymptomatic carotid artery stenosis as long as the patients would potentially be fit for and willing to consider carotid intervention if significant stenosis is discovered. In patients with symptomatic carotid stenosis 50-99%, who require both CEA and CABG, we suggest CEA before or concomitant with CABG to potentially reduce the risk of stroke and stroke/death. The sequencing of the intervention depends on clinical presentation and institutional experience.

Role of Carotid Artery Ultrasound Duplex Prior to Cardiac Surgery in Adults in Predicting Neurocognitive Complications

Background Neurocognitive complications (NCCs) after cardiac surgery are one of the most devastating complications. Significant internal carotid artery stenosis is assumed to be a predictor of NCCs. Carotid duplex ultrasound (DUS) is a non-invasive imaging study that remains the modality of choice and is routinely used in many centers for screening adult cardiac surgery patients prior to surgery. This study aims to assess the utility of preoperative carotid DUS in the prediction of NCCs in adult patients undergoing cardiac surgery in our center. Methods We retrospectively reviewed the medical records of patients who underwent coronary artery bypass graft (CABG), valvular or combined surgery, at King Faisal Cardiac Center in Jeddah between January 2017 and December 2018 (n = 229). The preoperative carotid DUS findings were evaluated. Risk factors associated with NCC were analyzed. Results Over the study period, a total of 229 patients underwent 233 procedures. Median age was 60 years (interquartile range [IQR] = 51-67 years), of whom 71% were males. Out of the diabetic patients, 67% had an HbA1C level above 7% pre-operatively. Carotid DUS was performed on 63% of patients, but only 6.9% developed a post-operative NCC. Patients who were actively smoking were more likely to develop NCC compared to nonsmokers or ex-smokers (14.7% vs 4.6%; p = 0.02), with an odds ratio of 3.6 (95% CI = 1.2-10.5). Patients who developed NCC had a significantly higher median intensive care length of stay (7 vs. 5 days; p = 0.05). Conclusions Although international guidelines clearly define which patient should get preoperative carotid DUS screening, the level of evidence is low. Based on our findings, preoperative routine use of carotid DUS prior to cardiac surgery has low utility in predicting NCC. We recommend a more tailored approach based on signs, symptoms, and high-risk features to optimize the utilization of resources, avoid unwarranted delays, and personalize patient care.

Validation of Risk Prediction Models to Detect Asymptomatic Carotid Stenosis

Background Significant asymptomatic carotid stenosis (ACS) is associated with higher risk of strokes. While the prevalence of moderate and severe ACS is low in the general population, prediction models may allow identification of individuals at increased risk, thereby enabling targeted screening. We identified established prediction models for ACS and externally validated them in a large screening population. Methods and Results Prediction models for prevalent cases with ≥50% ACS were identified in a systematic review (975 studies reviewed and 6 prediction models identified [3 for moderate and 3 for severe ACS]) and then validated using data from 596 469 individuals who attended commercial vascular screening clinics in the United States and United Kingdom. We assessed discrimination and calibration. In the validation cohort, 11 178 (1.87%) participants had ≥50% ACS and 2033 (0.34%) had ≥70% ACS. The best model included age, sex, smoking, hypertension, hypercholesterolemia, diabetes mellitus, vascular and cerebrovascular disease, measured blood pressure, and blood lipids. The area under the receiver operating characteristic curve for this model was 0.75 (95% CI, 0.74-0.75) for ≥50% ACS and 0.78 (95% CI, 0.77-0.79) for ≥70% ACS. The prevalence of ≥50% ACS in the highest decile of risk was 6.51%, and 1.42% for ≥70% ACS. Targeted screening of the 10% highest risk identified 35% of cases with ≥50% ACS and 42% of cases with ≥70% ACS. Conclusions Individuals at high risk of significant ACS can be selected reliably using a prediction model. The best-performing prediction models identified over one third of all cases by targeted screening of individuals in the highest decile of risk only.

Preoperative Carotid Duplex Scanning in Patients Undergoing Coronary Artery Bypass Grafting

OBJECTIVE

The aim of this study was to determine the prevalence and risk factors of carotid artery stenosis (CAS) using carotid duplex ultrasound in patients undergoing coronary artery bypass grafting (CABG).

METHODS

This retrospective study was conducted between January 2017 and January 2018 and included 166 consecutive patients [130 males (78.31%), 36 females (21.69%); mean age: 64.25±9.78 years] who underwent elective and isolated CABG. Patients who had significant CAS (≥50% stenosis) were compared with patients who had non-significant CAS (<50% stenosis). Logistic regression analysis was applied across the selected parameters to identify risk factors for significant CAS.

RESULTS

Of all patients, 36 (21.68%) had CAS ≥50% and 8 (4.81%) had unilateral carotid stenosis ≥70%. Carotid endarterectomy/CABG was performed simultaneously in five (3.01%) patients. None of these patients had cardiac and neurological problems during the postoperative period. The overall incidence of cerebrovascular accident (CVA) after CABG was 1.20% (n=2). Age (P=0.011) and history of CVA (P=0.035) were significantly higher in the CAS ≥50 group than in the CAS <50 group. Significant CAS was identified as a risk factor for postoperative CVA (P=0.013).

CONCLUSION

Age and history of CVA were identified as risk factors for significant CAS. Furthermore, significant CAS was identified as a risk factor for postoperative CVA. For this reason, carotid screening is recommended for patients undergoing CABG even in the absence of associated risk factors.

Prevalence of extracranial carotid atherosclerosis in the patients with coronary artery disease in a tertiary hospital in Malaysia

There is limited information regarding the prevalence of extracranial carotid atherosclerosis in the patients with coronary artery disease (CAD) undergoing coronary artery bypass graft (CABG) surgery in South East Asia. The primary objective was to assess the prevalence of extracranial carotid stenosis, raised carotid intima media thickness (CIMT), and plaques in the patients with CAD undergoing elective CABG. The secondary objective was to evaluate the risk factors for extracranial carotid atherosclerosis.A total of 119 consecutive patients with CAD undergoing elective CABG in a tertiary hospital in Malaysia were recruited. Data on the demographic characteristics and risk factors were collected. The ultrasound carotid Doppler findings comprising of raised CIMT, plaques, and stenosis in the extracranial carotid vessels were recorded.The mean age of the patients was 64.26 ± 10.12 (range 42-89). Most of the patients were men (73.1%). The patients consisted of 44 (37%) Malays, 26 (21.8%) Chinese, and 49 (41.2%) Indians.A total of 67 (56.3%) patients had raised CIMT, 89 (74.8%) patients had plaques, and 10 (8.4%) patients had stenosis in the internal and common carotid arteries. The mean age of patients with plaques was higher compared to those without plaques (66.00 ± 9.63 vs 59.10 ± 9.92, P = .001). The body mass index (BMI) of patients with stenosis was higher compared to those without stenosis (28.35 ± 4.92 vs 25.75 ± 3.16, P = .02).The patients with plaques were more likely to be older, whereas the patients with carotid stenosis were more likely to have higher BMI.

Neurological complications after cardiac surgery: a retrospective case-control study of risk factors and outcome

Background

To evaluate incidence, risk factors, and outcomes of postoperative neurological complications in patients undergoing cardiac surgery.

Methods

A total of 2121 patients underwent cardiac surgery between August, 2008 and December, 2013; 91/2121 (4.3%) underwent brain computed tomography (70/91, 77%) or magnetic resonance imaging (21/91, 23%) scan because of major stroke (37/2121, 1.7%) and a spectrum of transient neurological episodes as well as transient ischemic attacks and delirium /psychosis/seizures (54/2121, 2.5%). The mean age was 65.3 ± 12.1 years and 60 (65.9%) were male. Variables were compared among study- and matched-patients (n = 113) without neurological deficits.

Results

A total of 37/2121 (1.7%) patients had imaging evidence of stroke. Radiological examinations were done 5.72 ± 3.6 days after surgery. Patients with and without imaging evidence of stroke had longer intensive care unit length of stay (LOS) (13.8 ± 14.7 and 12.9 ± 15 days vs. 5.7 ± 12.1 days, respectively (p < 0.001) and hospital LOS (53 ± 72.8 and 35.5 ± 29.8 days vs. 18.4 ± 29.2 days, respectively (p < 0.001) than the control group. The hospital mortality of patients with and without imaging evidence of stroke was higher than the control group (7/37 patients [19%], and 12/54 patients [22%] vs. 4/115 patients [3%], respectively (p < 0.001). Multivariate analysis showed that bilateral internal carotid artery stenosis of any grade (p < .001), and re-do operations (p = .013) increased the risk of postoperative neurological complications.

Conclusions

Neurological complications after cardiac surgery increase hospitalization and mortality even in patients without radiologic evidence of stroke. Bilateral internal carotid artery stenosis of any grade, suggesting a diffuse patient propensity toward atherosclerosis, and re-do operations increase the risk of postoperative neurological complications.

A Review of Medical Doppler Ultrasonography of Blood Flow in General and Especially in Common Carotid Artery

Medical Doppler ultrasound is usually utilized in the clinical adjusting to evaluate and estimate blood flow in both the major (large) and the minor (tiny) vessels of the body. The normal and abnormal sign waveforms can be shown by spectral Doppler technique. The sign waveform is individual to each vessel. Thus, it is significant for the operator and the clinicians to understand the normal and abnormal diagnostic in a spectral Doppler show. The aim of this review is to explain the physical principles behind the medical Doppler ultrasound, also, to use some of the mathematical formulas utilized in the medical Doppler ultrasound examination. Furthermore, we discussed the color and spectral flow model of Doppler ultrasound. Finally, we explained spectral Doppler sign waveforms to show both the normal and abnormal signs waveforms that are individual to the common carotid artery, because these signs are important for both the radiologist and sonographer to perceive both the normal and abnormal in a spectral Doppler show.

The risk of carotid stenosis in head and neck cancer patients after radiation therapy

OBJECTIVES

Head and neck radiotherapy (RT) is a risk factor for cerebrovascular disease. We performed a retrospective cohort study to evaluate carotid artery stenosis (CAS) incidence in head and neck cancer (HNC) patients undergoing RT, characterizing associated risk factors.

MATERIALS AND METHODS

Records were retrospectively reviewed for HNC patients undergoing carotid ultrasound screening after definitive or adjuvant RT between January 2000 and May 2016. CAS was defined as ≥50% stenosis on imaging, stroke, or transient ischemic attack. Actuarial CAS rates were calculated by Kaplan-Meier method. Univariate and multivariate analyses predicted CAS risk based on carotid dosimetric and clinical parameters.

RESULTS

366 patients met inclusion criteria. Median time from RT completion to last follow-up was 4.1 yr. Actuarial risk for CAS was 29% (95% CI 22-36%) at 8 years. Univariate analysis showed that smoking (HR 1.7; 95% CI 1.1-2.7), hyperlipidemia (HR 1.6; 95% CI 1.03-2.6), diabetes (HR 2.8; 95% CI 1.6-4.8), coronary artery disease (HR 2.4; 95% CI 1.4-4.2), and peripheral artery disease (HR 3.6; 95% CI 1.1-11.6) were significantly associated with increased CAS. In multivariate analysis, diabetes was predictive of time to CAS (HR 1.9; 95% CI 1.1-3.4). Carotid dose parameters were not significantly associated with CAS.

CONCLUSIONS

CAS incidence is high after head and neck radiotherapy, gradually rising over time. No clear dose-response effect between carotid dose and CAS was identified for HNC patients. Carotid artery screening and preventative strategies should be employed in this high-risk patient population.

Should We Perform Carotid Doppler Screening Before Surgical or Transcatheter Aortic Valve Replacement?

BACKGROUND

Screening for internal carotid artery stenosis (ICAS) with Doppler ultrasound is commonly used before cardiovascular surgery. Nevertheless, the relationship between ICAS and procedure-related stroke in isolated aortic valve replacement is unclear.

METHODS

We retrospectively reviewed patients with artery stenosis who underwent ICAS screening before surgical (SAVR) or transcatheter aortic valve replacement (TAVR) between January 2007 and August 2014. Logistic regression models were used to determine the relation between post-procedure stroke and total (sum of left and right ICAS) and maximal unilateral ICAS. Age, sex, history of atrial fibrillation, cerebrovascular disease and diabetes, left ventricular ejection fraction, and procedure type were considered as covariates. Two-subgroup analyses were performed in patients who underwent TAVR and SAVR, adjusting for procedure specific details.

RESULTS

A total of 996 patients underwent ICAS screening before TAVR (n = 467) or SAVR (n = 529). The prevalence of at least ≥70% ICAS was 5.2% (n = 52) and incidence of 30-day stroke was 3.4% (n = 34). Eight patients who underwent carotid intervention before valve replacement and 6 patients with poor Doppler images were excluded from the final analysis. We found no statistically significant association between stroke and either the total or maximal unilateral ICAS for all patients (p = 0.13 and p = 0.39, respectively) or those undergoing TAVR (p = 0.27 and p = 0.63, respectively) or SAVR (p = 0.21 and p = 0.36, respectively).

CONCLUSIONS

We found no statistically significant association between ICAS severity procedure-related stroke after aortic valve replacement. This suggests that universal carotid Doppler screening before isolated TAVR or SAVR is unnecessary.

Rapid High-Volume Population Screening for Three Major Risk Factors of Future Stroke: Phase I Results

Three proximate risk factors for stroke are carotid stenosis, atrial fibrillation, and hypertension. Phase I of this prospective study was designed to establish the prevalence of these conditions among a population of health maintenance organization beneficiaries by using a rapid screening protocol in order to risk-stratify patients for appropriate management and subsequent cohort analysis. Patients at a tertiary care medical center were screened for stroke risk by using directed history, a 3-minute carotid “quick-scan” protocol, an EKG lead II rhythm strip, and bilateral arm blood pressures. Patients with any abnormal result underwent specific diagnostic consultation with vascular surgery, cardiology, or primary care. These evaluations included formal carotid duplex ultrasound, 12-lead EKG ± Holter monitor, and 5-day blood pressure check. Patients were then stratified into risk cohorts for appropriate management and future analysis of stroke incidence and outcomes. In 8 hours on a single day in October 2002, 294 patients (mean age 69) were screened. Combining history with results of screening and diagnostic tests, the overall prevalence of carotid stenosis was 6% (n= 17/294), atrial fibrillation 7% (n= 21/294), and severe hypertension 5% (n= 16/294). Fifty-nine patients (20%) screened positive for carotid stenosis by “quick-scan,” and 29% (n= 17/59) of these had confirmed stenosis (>50%) in 1 or both arteries by formal duplex. The prevalence of confirmed carotid stenosis was 37% among those screening positive for 1 artery (odds ratio [OR] 14.6; p <0.001) and 75% among those screening positive for both (OR 74.7; p <0.001). Significant independent predictors of carotid stenosis by multivariate analysis included coronary artery disease or myocardial infarction, smoking, stroke or transient ischemic attack, male gender, and white race (all p <0.05). The prevalence of confirmed stenosis was 10% with any 3 predictors alone (OR 2.5; p <0.05), 31% with any 4 (OR 21.2; p <0.001), and 50% with all 5 (OR 46.5; p <0.001). Thirty-three patients (11%) were found to have a previously unidentified and untreated arrhythmia, and 12% (n= 4/33) of these had confirmed new atrial fibrillation; 158 patients (54%) had moderate hypertension and 16 (5%) had severe hypertension (>180/100). Overall, 82% (n= 242/294) of patients screened required additional diagnostic tests. Based on these results, 11% (n= 31/294) of patients were stratified as high risk, 64% (n= 188/294) as moderate risk, and 25% (n= 75/294) as low risk for future stroke. Rapid and efficient screening of a large population for stroke risk factors is feasible. The prevalence of undiagnosed, unsurveilled, and untreated carotid stenosis, atrial fibrillation, and severe hypertension is significant, as 75% of patients screened had 1 or more confirmed major risk factors for stroke. Phase II of this study will investigate the degree of stroke risk reduction possible with a multidisciplinary approach to early identification and aggressive treatment of these risks.

Prevalence of carotid artery stenosis in Chinese patients with angina pectoris

BACKGROUND

The prevalence of carotid artery stenosis (CAS) in Chinese patients with angina pectoris is unknown.

METHODS

The study population consisted of 989 consecutive patients who were scheduled to undergo nonemergent coronary angiography for suspicion of coronary artery disease (CAD) because of angina pectoris between January 2013 and December 2014. All patients underwent carotid ultrasonography to screen for CAS within one month before or after coronary angiography. We defined cases with 0-50%, 50%-70%, and >70% stenosis as mild, moderate, and severe stenosis, respectively.

RESULTS

CAD was presented in 853 patients (86.2%) of whom 191 patients (19.3%) had 1-vessel disease, 246 patients (24.9%) had 2-vessel disease and 416 patients (42.1%) had 3-vessel disease; left main trunk stenosis present in 137 patients (13.9%). In carotid ultrasonography, the prevalence of mild, moderate, and severe stenosis as well as that of total occlusion of the carotid artery was 54.5%, 13%, 4.7% and 0.8%, respectively. Significant CAS (>50% stenosis and total occlusion) was present in 10.3%, 13.9%, 19.9% and 22.8% of patients with 0-vessel, 1-vessel, 2-vessel and 3-vessel CAD. The severity of CAS was directly correlated (r=0.194, P<0.001) with the extent of CAD. The independent predictors of severe CAS and total carotid artery occlusion were increased age, male sex, hypertension, diabetes mellitus, hyperhomocysteinemia, a previous history of stroke and 3-vessel CAD.

CONCLUSIONS

The prevalence of CAS was not rare in China when compared with that in western countries, and the presence of CAS was weakly correlated with the extent of CAD. Screening for CAS should be recommended in Chinese patients with CAD, especially in those with one or more CAS-associated risk factors.

Risk Factors for Carotid Artery Stenosis in Chinese Patients Undergoing Coronary Artery Bypass Graft Interventions

Current guidelines established in the USA and Europe for coronary artery bypass graft (CABG) suggest that patients ≥65 and ≥70 years of age, or with certain atherosclerotic-risk factors, should be screened preoperatively for extracranial carotid artery stenosis (CAS) to assess their risk of perioperative stoke. We sought factors that should be taken into consideration when treating Chinese CABG patients using CABG guidelines based on an analysis of CAS in a large cohort of Chinese CABG patients. We analyzed data for 1558 Chinese CABG patients who were screened preoperatively for CAS using duplex ultrasonography at a single institution. We defined significant and severe CAS as ≥50% and ≥70% stenosis, respectively, in one or more common or internal carotid arteries. We investigated the prevalence of CAS, the incidence of perioperative stroke, and the risk factors for CAS in the CABG cohort. The prevalence of CAS in the CABG cohort was 21.2%. Multivariate stepwise logistic regression analysis showed that an age ≥50 years and a history of smoking (odds ratios = 8.36 and 1.83, respectively) were independent risk factors for CAS (P < 0.05 for both). The incidence of perioperative stroke among CABG patients with significant or severe CAS was significantly higher (2.4% and 2.9%, respectively) than in CABG patients with <50% stenosis (0.5%; P = 0.004 and 0.029, respectively). Chinese CABG patients with a history of smoking or ≥50 years of age should undergo preoperative screening for CAS to assess their risk of perioperative stroke.

Carotid stenosis management: a review for the internist

Stroke is one of the most important causes of mortality and morbidity worldwide and, for a long time, was the leading cause of death in developed countries. Atherothrombotic carotid stenosis is one of the most important etiologies behind this event. If properly recognized and treated, lives can be saved, as well as long-term disabilities prevented. With population aging and improvements in surgical and clinical care, patients with several comorbidities will be referred for revascularization procedures more frequently, posing a challenge for physicians. The purpose of this review is to provide internists and clinicians with information based on several studies so they can offer to their patients, the best evidence-based care, indicating appropriate medical therapy, as well as referral to a vascular surgeon, or what contraindicates endarterectomy or angioplasty, depending on individual characteristics.

Screening for carotid artery stenosis and renal artery stenosis in patients undergoing tunneled cuffed hemodialysis catheter placement

In this study, we noted the common risk factors with atherosclerosis and chronic renal disease. We, therefore, hypothesized that the placement of a dialysis catheter would be a useful marker in identifying populations at increased risk of vascular disease (carotid, renal, and aortic). To further explore this issue, we examined the results of duplex scanning of the carotid arteries and aortorenal arteries in patients undergoing dialysis catheter placement. Over 49 months, each of the 123 patients who underwent permanent tunneled dialysis catheter placement received a carotid duplex study. Twelve patients (9.8%) had ≥ 60% stenosis and 8 patients (6.5%) had 70% to 99% stenosis. Furthermore, 109 patients who underwent a aortorenal artery duplex study were also analyzed. The study population demonstrated a prevalence rate of 3.7% for abdominal aorta aneurysm (AAA) and 4.6% for renal artery stenosis (RAS). Based upon these data, we suggest performing routine carotid duplex scans in patients who will also receive dialysis catheter placement. However, the data did not support routine screening of AAA or RAS.

Assessment of carotid artery stenosis before coronary artery bypass surgery. Is it always necessary?

BACKGROUND

Extracranial internal carotid artery stenosis is a risk factor for perioperative stroke in patients undergoing coronary artery bypass surgery (CAB). Although selective and non-selective methods of preoperative carotid screening have been advocated, it remains unclear if this screening is clinically relevant.

AIM

To test whether selective carotid screening is as effective as non-selective screening in detecting significant carotid disease.

METHODS

The case records of patients consecutively undergoing CAB were reviewed. Patients were stratified retrospectively into high- or low-risk groups according to risk factors for significant carotid stenosis and perioperative stroke: peripheral vascular disease (PVD), carotid bruit, diabetes mellitus, age >70 years and/or history of cerebrovascular disease. Prevalence of carotid stenosis detected by ultrasonography, surgical management and perioperative stroke rates were determined in each group.

RESULTS

Overall, 205 consecutive patients underwent preoperative carotid screening. The prevalence of significant carotid stenosis was 5.8%. Univariate analysis confirmed that PVD (P=0.005), carotid bruit (P=0.003) and diabetes mellitus (P=0.05) were significant risk factors for stenosis. Carotid stenosis was a risk factor for stroke (P=0.03). Prevalence of carotid stenosis was higher in the high-risk group (9.1%) than the low-risk group (1.2%) (P<0.05). All concomitant or staged carotid endarterectomies/CAB (5/205) and all patients who had perioperative strokes (5/205) were in the high-risk group (P=0.01).

CONCLUSION

In our cohort, selective screening of patients aged >70 years, with carotid bruit, a history of cerebrovascular disease, diabetes mellitus or PVD would have reduced the screening load by 40%, with trivial impact on surgical management or neurological outcomes.

Current outcomes of simultaneous carotid endarterectomy and coronary artery bypass graft surgery in North America

OBJECTIVE

Management of patients with concomitant carotid and coronary artery disease has been controversial. Divergent strategies have been employed, including simultaneous carotid endarterectomy and coronary bypass (SCC) versus various staged procedures. Although no strict comparison group is available, this study defines current outcomes of SCC, compared qualitatively to two reference categories.

METHODS

Utilizing the STS database from 2003 to 2007, patients who had SCC were compared with patients with cerebrovascular disease who had coronary bypass (CABG) with prior carotid endarterectomy (CEA), and those with carotid Doppler stenosis >75% and no carotid intervention. Logistic regression analysis adjusted for differences in baseline characteristics and operative mortality (OM), and a composite of neurological complications (NC) was assessed.

RESULTS

Of 745,769 patients who underwent isolated CABG with/without CEA, 108,212 (14%) had cerebrovascular disease. Of this group, 5,732 (5%) underwent SCC. The SCC group had more males and lower preoperative risk factors. After statistical adjustment for all baseline differences, SCC had clinically and statistically higher OM and NC compared with any of the reference groups, with 20-40% higher event risk.

CONCLUSIONS

Although no quantitative control group exists for comparison, SCC as recently performed in North America has a high risk compared with any of the reference groups. Suboptimal results associated with the SCC strategy suggest a need for quality improvement and research on the optimal management of patients with simultaneous carotid and coronary disease.

Implementation and efficacy of selective sonographic screening for carotid disease before cardiac surgery

BACKGROUND

Preoperative carotid sonography with consecutive preventive strategies might reduce stroke risk during cardiac surgery. Since routine sonography in all patients may be unfeasible, an approach to examine preselected patients was investigated.

METHODS

A prognostic model predicting carotid disease was developed using the clinical data of 1,768 routinely examined patients. It recommended 1,018 of 4,814 patients of a following collective for selective sonography. Patients recommended for preoperative sonography were compared to those selected in clinical practice.

RESULTS

Besides the evaluated predictor variables, a history of syncope/cardiogenic shock and of pulmonary disease was associated with patient selection for sonography in clinical practice, even though both variables were not associated with severe carotid disease. In patients who underwent sonography, although this was not recommended by the prognostic model, severe carotid disease was estimated lower than what was actually detected, suggesting a change in relative relevance of predicting variables along with the change in frequencies of patients' cardiovascular characteristics.

CONCLUSION

Prognostic models for selective screening before cardiac surgery may require reevaluation over time, especially when baseline characteristics used for prediction have changed. Criteria used in clinical practice to select patients for screening may differ from those recommended by investigational studies.

Low prevalence of significant carotid artery disease on ultrasound in patients proceeding to coronary artery bypass surgery

BACKGROUND

Cardiothoracic surgery is associated with an increased risk of perioperative stroke. Preoperative carotid ultrasonography can identify significant stenosis, but there is debate about the value of screening. The aims of this study were to (i) determine the prevalence of significant carotid artery disease in screened patients undergoing cardiothoracic surgery and (ii) correlate their ultrasonographic findings with perioperative strokes.

METHODS

Retrospective analysis of 166 patients (118 men, 48 women) who underwent a preoperative carotid ultrasound and coronary artery bypass graft surgery (CABG) from 2004 to 2007. Perioperative strokes were recorded and compared with ultrasonographic and clinical data. A separate cohort of 1423 patients (1064 men, 359 women) who underwent CABG over the same period was also evaluated.

RESULTS

Only 11 screened patients (6.6%) had significant (>70%) carotid artery disease and two of these underwent simultaneous carotid endarterectomy. There were five perioperative strokes in screened patients, four of which occurred in individuals with <50% disease. Compared with the non-screened cohort, ultrasound screened patients were older and more likely to have a prior stroke or transient ischaemic attack, hypertension, hypercholesterolaemia, peripheral vascular disease and/or renal impairment than non-screened patients. There was no significant difference in perioperative strokes compared with non-screened patients (3% vs 1.2% respectively, P= NS).

CONCLUSION

There is a low prevalence of significant carotid artery disease in ultrasound screened patients. The risk of perioperative strokes in screened patients is low and not significantly different from non-screened patients.

Selective Screening for Asymptomatic Carotid Artery Disease Prior to Isolated Heart Valve Surgery

Objective

To assess the yield of screening for asymptomatic carotid artery disease prior to isolated heart valve surgery (IHVS).

Methods

Retrospective analysis of the preoperative carotid duplex scans performed in neurologically asymptomatic patients who underwent IHVS between 2003 and 2006 was performed. Internal carotid artery (ICA) stenosis of 70% was considered significant. Patients with concomitant coronary artery disease were excluded.

Results

A total of 177 patients underwent IHVS (one valve in 165 and 2 valves in 12 patients). No or minor ICA disease detected in 172 patients. Four patients (2.25%) had significant unilateral ICA stenosis and 1 patient (0.56%) had unilateral ICA occlusion. Three patients (1.69%) suffered postoperative stroke, while 2 patients (1.1%) suffered transient ischemic attacks. All neurologically affected patients had normal preoperative carotid duplex. The in-hospital mortality was 4.5%.

Conclusion

Prevalence of significant ICA disease is low in patients undergoing IHVS. This population does not benefit from preoperative carotid screening.

Low prevalence of significant carotid artery disease in Iranian patients undergoing elective coronary artery bypass

BACKGROUND

Coronary artery bypass grafting ranks as one of the most frequent operations worldwide. The presence of carotid artery stenosis may increase the stroke rate in the perioperative period. Routine preoperative noninvasive assessment of the carotid arteries are recommended in many institutions to reduce the stroke rate.

METHODS

271 consecutive patients undergoing coronary artery bypass grafting at Shaheed Madani hospital of Tabriz, Iran (age, 58.5 Y; 73.1% male) underwent preoperative ultrasonography for assessment of carotid artery wall thickness.

RESULTS

Plaque in right common, left common, right internal and left internal carotid arteries was detected in 4.8%, 7.4%, 43.2% and 42.1% of patients respectively. 5 patients (1.8%) had significant (<50%) and 3 (1.1%) patients had critical (<70%) stenosis in internal carotid arteries. Plaque formation in common carotid was not significantly different between two genders but the stenosis of left internal carotid was more frequently seen among men. Patients with plaques in right or left internal carotid arteries were significantly older.

CONCLUSION

Consecutive Iranian patients undergoing elective coronary artery bypass surgery show a very low prevalence of significant carotid artery disease.

Guidelines for Screening of Extracranial Carotid Artery Disease: A Statement for Healthcare Professionals from the Multidisciplinary Practice Guidelines Committee of the American Society of Neuroimaging; Cosponsored by the Society of Vascular and Interventional Neurology

The aim of this new statement is to provide comprehensive and timely evidence-based recommendations on the screening for asymptomatic carotid artery stenosis in the general population and selected subsets of patients. Recommendations are included for high-risk persons in the general population; patients undergoing open heart surgery including coronary artery bypass surgery; patients with peripheral vascular diseases, abdominal aortic aneurysms, and renal artery stenosis; patients after radiotherapy for head and neck malignancies; patients following carotid endarterectomy, or carotid artery stent placement; patients with retinal ischemic syndromes; patients with syncope, dizziness, vertigo or tinnitus; and patients with a family history of vascular diseases and hyperhomocysteinemia. The recommendations are based on prevalence of disease, anticipated benefit, and concurrent guidelines from other professional organizations in selected populations.

Diagnosing carotid stenosis by Doppler sonography: state of the art

OBJECTIVE

The goal of this review article is to present the state of the art in the clinical applications and technical performance and interpretation of carotid sonographic examinations.

METHODS

Relevant publications regarding color and duplex Doppler sonography (CDDS) of the carotid arteries extracted from a computerized database (MEDLINE) and from references cited in these articles not appearing on the Internet were reviewed.

RESULTS

The ability to quickly and efficiently identify stenosis in the carotid artery is an important goal for clinicians and vascular surgeons. Identification of potentially treatable carotid stenosis enables selection of appropriate candidates for endarterectomy or stent implantation. Advances in performance and interpretation of carotid sonographic studies over the last 20 years have been driven by technological improvements in gray scale and CDDS examinations and have made carotid sonography an important means to reach this goal. On the basis of CDDS, intima-media thickness measurements and plaque location and characterization on gray scale imaging, flow disturbance and areas of stenosis on color Doppler sonography, and flow velocities on spectral Doppler sonography are obtained. The degree of the diameter of a stenosis of the internal carotid artery is the main parameter used for therapeutic approaches. Advantages and limitations of the method are included.

CONCLUSIONS

Carotid sonography is a unique imaging method for the investigation of carotid abnormalities. Noninvasive, accurate, and cost-effective, it provides morphologic and functional information. It is increasingly becoming the first and often the sole imaging study before endarterectomy, whereas costly and invasive procedures are reserved for special cases.

Screening angiography of supraaortic vessels performed by invasive cardiologists at the time of cardiac catheterization: indications and results

An aging population makes multiple vascular distributions more likely in patients arriving at the cath lab for coronary artery angiography or complete cardiac catheterization. Whether or not screening angiography of supraaortic vessels can be performed at the time of cardiac catheterization by the invasive cardiologist is still debatable. We sought to determine safety and utility of performing angiography of supraaortic vessels during cardiac catheterization. Medical records of all patients undergoing combined coronary and noncoronary angiography between May 1998 and December 2002 was retrospectively reviewed. One hundred and forty patients (80 males, mean age 67.8 +/- 5.4 years) underwent combined cardiac catheterization and angiography of supraaortic vessels. Carotid artery angiography was performed at the same time of cardiac catheterization in 62 patients and subclavian artery angiography in the other 78 patients. Significant findings were reported in 32 (22.8%) patients. Complications included 1 transient ischemic attack and 2 carotid spasm resolved with nitrates infusion. In most cases the same standard catheters used during coronary angiography were used also for noncoronary angiography (119 patients, 85%). The incidence of significant angiographic findings and the relatively frequent association of CAD with supraaortic vessel atherosclerosis supports combined cardiac catheterization and angiography of supraaortic arteries but only in patients with multivessel coronary artery disease.

Mandatory versus selective preoperative carotid screening: a retrospective analysis

BACKGROUND

Extracranial internal carotid artery stenosis is a risk factor for perioperative stroke in coronary artery bypass (CAB) surgery. Although both selective and nonselective methods of preoperative carotid screening have been advocated, it is unclear which approach is most clinically efficacious.

METHODS

Hospital records for 1421 consecutive CAB patients from January 2000 through April 2002 were reviewed. Univariate and multivariate analyses were performed across selected parameters to identify risk factors for significant carotid stenosis (> or = 70%). Patients were retrospectively stratified into high- or low-risk groups based on risk factors common to carotid stenosis and perioperative stroke. The prevalence of carotid stenosis, surgical management, and perioperative stroke rates were determined for each group.

RESULTS

One-thousand one-hundred thirty-eight patients out of 1421 patients (80.1%) underwent preoperative carotid screening. The prevalence of significant carotid stenosis was 13.4%. Univariate risk factors for stenosis included an age of more than 65 years, peripheral vascular disease, prior cerebrovascular accident, history of cerebrovascular disease, left main coronary disease, carotid bruit, female gender, and hypertension. Carotid stenosis was a risk factor for stroke, neurologic injury, in-hospital mortality, and longer hospitalization. Prevalence of carotid stenosis was greater in high-risk patients (17.8%, N = 708) versus low-risk patients (6.1%, N = 426). Concomitant or staged carotid endarterectomy (CEA)/CAB was more commonly performed in the high-risk group (5.8% vs. 1%, p < 0.001). All nine patients with significant carotid stenosis who suffered perioperative strokes were in the high-risk group (9 out of 708 vs 0 out of 426, p = 0.016).

CONCLUSIONS

In our cohort, selectively screening only patients with either an age of more than 65, carotid bruit, or cerebrovascular disease would have reduced the screening load by nearly 40% with negligible impact on surgical management or neurologic outcomes.

Focused screening for occult carotid artery disease: patients with known heart disease are at high risk

OBJECTIVES

Stroke puts a major financial burden on our healthcare system. However, carotid duplex scanning performed as a screening test for occult carotid artery stenosis (CAS) currently is not reimbursed by Medicare. The goals of this study were to develop a cost-effective stroke screening program, to determine the prevalence of potential causes of stroke in this population, and to define a population at high risk in which screening would be most effective.

METHODS

In a community-based stroke screening program, patients were eligible if they were older than 60 years and had a history of either hypertension, heart disease, or cigarette smoking, or a family history of stroke. Screening included blood pressure determination, an electrocardiographic rhythm strip, and a previously validated modified carotid duplex ultrasound examination to detect CAS 50% or greater. The relationships between standard demographic risk factors and screening outcomes were analyzed.

RESULTS

Screening was performed in 610 patients. Unilateral or bilateral CAS was detected in 66 patients (10.8%). The finding of occult CAS was more prevalent than that of new hypertension (2.6%) or new atrial fibrillation (0.5%). Patients with known hypertension were significantly more likely to have CAS than were those without hypertension (12.7% vs 7.8%; P =.05). Patients with heart disease were significantly more likely to have CAS than were those without heart disease (18.2% vs 8%; P <.0001). Patients with both risk factors were significantly more likely to have occult carotid artery disease than were patients without either risk factor (22.1% vs 8.5%; P <.0001). Multivariate analysis with logistic regression revealed a history of heart disease as an independent predictor of occult carotid artery disease (odds ratio 95% confidence interval, 1.4-4.4). Type of heart disease was not a significant factor in predicting occult CAS. Direct cost of the screening, including community outreach, nurses, technicians, support staff, and miscellaneous expenses, was less than $75 per patient.

CONCLUSIONS

In a screening program for treatable causes of potential stroke, CAS was the most commonly diagnosed disease. More than one of every five patients with known hypertension and heart disease had occult CAS. Known heart disease of any type was a significant independent predictor of occult CAS. Screening for treatable causes of potential stroke can be cost-effective. This information could help to further target populations to screen for occult CAS and to justify reimbursement for screening carotid duplex scanning examinations.

A model for predicting occult carotid artery stenosis: screening is justified in a selected population

OBJECTIVES

The diagnosis and treatment of carotid artery disease is an integral part of stroke prevention. However, a population of patients who would benefit from screening for carotid artery stenosis has not been well defined. As part of an institutional stroke-screening program, a modified, rapid duplex scan was developed to evaluate patients for occult carotid stenosis. The goal of this study was to evaluate risk factors predictive of carotid stenosis in a selected population, and to identify patients who would benefit from carotid screening.

METHODS

Patients were eligible for the study if they were >60 years of age and had a history of hypertension, heart disease, current smoking, or family history of stroke. A modified carotid duplex scan that had been previously validated against formal duplex scanning was utilized; this involved visualization of the carotid bulb and proximal internal carotid artery where Doppler flow velocities were obtained and recorded.

RESULTS

Screening was performed on 394 patients. Thirty-eight patients (9.6%) had either unilateral or bilateral carotid stenosis of > or =50%. Risk factors evaluated included smoking, hypertension, cardiac disease, or hypercholesterolemia. If none of these risk factors was present, the incidence of carotid stenosis was 1.8%. This increased to 5.8% with one risk factor, 13.5% with two risk factors, and 16.7% with three risk factors. Two of three patients with all four risk factors had carotid stenosis (66.7%). Logistic regression and prespecified contrast statements for multiple comparisons were used to assess the relationship between the presence of risk factors and occult carotid artery stenosis. The presence of any one of these risk factors was associated with a statistically significant increase in the presence of occult carotid stenosis (P <.01). This was also statistically significant for the presence of any two risk factors (P <.01) or three risk factors (P <.05).

CONCLUSION

The prevalence of carotid stenosis significantly increases with the presence of one or more identifiable demographic risk factors in a selected population. Assuming the diagnosis and treatment of carotid stenosis are fundamental to stroke prevention, screening for carotid artery disease is justified in this group of patients.