Screening Carotid Sonography Before Elective Coronary Artery Bypass Graft Surgery: Who Needs It

Concomitant Carotid and Coronary Artery Disease Management: A Review of the Literature

This review examines current evidence regarding management of patients with both coronary and carotid artery disease. It highlights the elevated stroke risk after surgery for this cohort and scrutinizes approaches to minimize this risk. Various revascularization methods are outlined, including carotid endarterectomy (CEA), carotid artery stenting (CAS), and staged versus simultaneous surgical approaches. The importance of judiciously screening coronary artery bypass grafting (CABG) candidates for carotid stenosis is emphasized, suggesting risk factor-based targeted screening is noninferior to indiscriminate screening. Efficacy comparisons are made between revascularization strategies such as staged versus synchronous CEA/CABG, CAS, and hybrid techniques. Controversies surrounding necessity and optimal timing of carotid revascularization in asymptomatic patients are addressed, indicating a need for rigorous randomized controlled trials to establish definitive treatment algorithms.

Carotid Ultrasound Assessment Prior to Coronary Artery Bypass Grafting - An Irish Cardiac Surgery Center's Experience

BACKGROUND

Carotid stenosis is a risk factor for cerebrovascular accident (CVA) following coronary artery bypass grafting (CABG). Guidelines recommend selective preoperative screening with Doppler ultrasound (US) but nonselective application is commonplace. Recent data has questioned the efficacy of perioperative carotid intervention, challenging the value of this practice. We thus aimed to analyze the utility of carotid US assessment prior to CABG in our institution.

METHODS

This was a retrospective review of all patients over 18 that underwent a nonemergency CABG in a single Irish cardiac surgery center from January 2019 to December 2022.

RESULTS

1161 subjects were included. 1084/1161 (93.36%) underwent US assessment. 41/1084 (3.8%) had ≥70% stenosis and 189/1084 (17.5%) had ≥50% stenosis. 32/1084 (2.95%) underwent confirmatory imaging and 7/1084 (0.64%) underwent carotid intervention. Postoperative CVA occurred in 18/1161 (1.55%) and ≥70% (P = 0.024) and ≥50%(P < 0.001) carotid stenosis were associated with same. Chronic kidney disease (odds ratio [OR] = 1.66,P = 0.01), decreasing hemoglobin (OR = 1.13,P = 0.019), increasing age (OR = 1.03,P = 0.011) and being a current (OR = 3.21,P < 0.001) or ex-smoker (OR = 1.82,P = 0.004) were risk factors for ≥50% carotid stenosis on logistic regression. Multivessel coronary artery disease (CAD) was not associated with carotid stenosis (P = 0.563). Of those that underwent carotid intervention, 0/7 (0%) suffered a CVA, but this protective effect failed to reach statistical significance for those with ≥70% (P = 1) or ≥50% (P = 1) carotid stenosis.

CONCLUSIONS

Carotid US screening altered the management of only a small proportion of CABG patients despite near universal application, challenging the effectiveness of this practice. Multivessel CAD was not associated with carotid stenosis despite European guidelines listing it as screening criteria. Predictive models must be developed using identified risk factors to enable targeted preoperative screening.

Infrared (IR) thermography as a potential screening modality for carotid artery stenosis

In the present study, an infrared (IR) thermal camera was used to map the temperature of the target skin surface, and the resulting thermal image was evaluated for the presence of carotid artery stenosis (CAS). In the presence of stenosis in the carotid artery, abnormal temperature maps are expected to occur on the external skin surface, which could be captured and quantified using IR thermography. A Duplex Ultrasound (DUS) examination was used to establish the ground truth. In each patient, the background-subtracted thermal image, referred to as full thermal image, was used to extract novel parametric cold thermal feature images. From these images, statistical features, viz., correlation, energy, homogeneity, contrast, entropy, mean, standard deviation (SD), skewness, and kurtosis, were calculated and the two groups of patients (control and diseased: a total of 80 carotid artery samples) were classified. Both cut-off value- and support vector machine (SVM)-based binary classification models were tested. While the cut-off value classification model resulted in a moderate performance (70% accurate), SVM was found to have classified the patients with high accuracy (92% or higher). This preliminary study suggests the potential of IR thermography as a possible screening tool for CAS patients.

The relationship between the carotid and coronary artery stenosis: a study based on angiography

Objective: Previous studies have demonstrated a strong association between carotid artery stenosis (CAS) and coronary artery stenosis disease (COAS). However, prior evaluated methods are non-invasive examinations. This study was aimed to access the relationship between CAS and COAS by the means of angiography. Methods: This is a single-center, retrospectively reviewed study based on digital subtraction angiography (DSA) of carotid artery and coronary artery angiography (CAG). We collected a total of 231 patients undergoing DSA and CAG at the same-day between June 2013 and May 2015. The patients were stratified according to the degree of CAS and COAS, mild stenosis <50%, moderate stenosis 50-69%, severe stenosis 70-99%, occlusion 100%. The correlation of CAS with COAS, as well as the risk factors, was analyzed. Results: A total of 231 patients was enrolled in this study, male 71.9% (166/231). The age ranges from 32 to 80, mean age 60.06 ± 9.98. Of these patients, 79 patients were severe CAS and 128 patients were severe COAS. Statistical analysis demonstrated that the independent risk factors of severe COAS ≥70%, were age, sex, previous cerebral infraction, coronary heart diseases, and coronary artery surgery. CAS was associated with COAS (Spearman r = 0.333, P < 0.01). The more serious the CAS, the more involved COAS (Kendall's tab-b = 0.294, p < 0.01). Conclusions: The DSA confirmed CAS was associated with CAG confirmed COAS. The heavier the CAS is, the more the number of the affected coronary artery.

Prevalence of carotid artery stenosis in neurologically asymptomatic patients undergoing coronary artery bypass grafting for coronary artery disease: Role of anesthesiologist in preoperative assessment and intraoperative management

Objective(s):

This study aimed to determine the prevalence of carotid artery stenosis (CAS) due to atherosclerosis in neurologically asymptomatic patients undergoing coronary artery bypass grafting (CABG) for coronary artery disease (CAD). It contemplated a greater role for the cardiac anesthesiologist in the perioperative management of such patients with either previously undiagnosed carotid artery disease or towards re-assessment of severity of CAS.

Design:

Prospective, observational clinical study.

Setting:

Operation room of a cardiac surgery centre of a tertiary teaching hospital.

Participants:

A hundred adult patients with New York Heart Association (NYHA) classification I to III presenting electively for CABG.

Interventions:

All patients included in this study were subjected to ultrasonic examination by means of acarotid doppler scan to access for presence of CAS just prior to induction of general anesthesia.

Measurements and Main Results:

Based on parameters measured using carotid doppler, the presence of CAS was defined using standard criteria. The prevalence of CAS was found to be as high as 38% amongst the patients included in our study. The risk factors for CAS were identified to be advanced age, history of smoking, diabetes mellitus, dyslipidaemia and presence of a carotid bruit.

Conclusion:

This study points towards the relatively wide prevalence of carotid artery disease in neurologically asymptomatic patients undergoing CABG for CAD in the elective setting. It highlights the need to routinely incorporate carotid ultrasonography in the armamentarium of the cardiac anesthesiologist as standard of care for all patients presenting for CABG.

Nonselective carotid artery ultrasound screening in patients undergoing coronary artery bypass grafting: Is it necessary?

OBJECTIVES

To determine whether nonselective preoperative carotid artery ultrasound screening alters management of patients scheduled for coronary artery bypass grafting (CABG), and whether such screening affects neurologic outcomes.

METHODS

From March 2011 to September 2013, preoperative carotid artery ultrasound screening was performed on 1236 of 1382 patients (89%) scheduled to undergo CABG. Carotid artery stenosis (CAS) was classified as none or mild (any type 0%-59% stenosis), moderate (unilateral 60%-79% stenosis), or severe (bilateral 60%-79% stenosis or unilateral 80%-100% stenosis).

RESULTS

A total of 1069 (86%) had <moderate; 90 (7.3%) had moderate; and 77 (6.2%) had severe CAS. Of those with moderate CAS, 4 (4.4%) had preoperative confirmatory testing, and 1 (1.1%) underwent combined CABG + carotid endarterectomy (CEA); 11 (12%) had off-pump surgery. Of those with severe CAS, 18 (23%) had confirmatory testing, and 18 (23%) underwent combined CABG + CEA; 6 (7.8%) had off-pump surgery. Stroke occurred in 14 of 1069 (1.3%) patients with <moderate CAS; 2 of 90 (2.2%) of those with moderate CAS; and 2 of 77 (2.6%) of those with severe CAS (P = .3). In patients with ≥moderate CAS, 1 of 19 (5.3%) undergoing CABG + CEA and 3 of 148 (2.0%) undergoing CABG alone experienced stroke (P = .4). In patients with moderate CAS, stroke occurred in 1 of 11 (9.1%) off-pump and 1 of 79 (1.3%) on-pump patients (P = .2). In patients with severe CAS, stroke occurred in 1 of 6 (17%) off-pump and 1 of 71 (1.4%) on-pump patients (P = .15).

CONCLUSIONS

Routine preoperative carotid artery evaluation altered the management of a minority of patients undergoing CABG; this did not translate into perioperative stroke risk. Hence, a more targeted approach for preoperative carotid artery evaluation should be adopted.

Does preoperative carotid stenosis screening reduce perioperative stroke in patients undergoing coronary artery bypass grafting?

A number of institutions routinely perform carotid artery ultrasound screening before coronary artery bypass grafting (CABG) to identify carotid artery disease requiring revascularization before or during CABG, with the expectation of reducing perioperative neurologic events. The assumptions are that carotid disease is causally related to perioperative stroke and that prophylactic carotid revascularization decreases the risk of post-CABG neurologic events. Although carotid artery stenosis is a known risk factor for perioperative stroke in patients undergoing CABG, it might be a surrogate marker for diffuse atherosclerotic disease rather than a direct etiologic factor. Moreover, the benefit of prophylactic carotid revascularization in patients with asymptomatic unilateral carotid disease is uncertain. Therefore, we have reviewed the literature for evidence that preoperative carotid artery screening, by identifying patients with significant carotid artery stenosis and altering their management, reduces perioperative neurologic events in those undergoing CABG.

Perioperative management of combined carotid and coronary artery bypass grafting procedures

The objective of this review is to provide a high level overview on current thinking for treatment of patients with combined carotid and coronary artery disease given that these patients are at higher risk of adverse cardiac events, stroke, and death. This review discusses (1) the current literature addressing perioperative stroke risk in the setting of coronary artery bypass graft, (2) the literature regarding different surgical approaches when both carotid and coronary revascularization are being considered, and (3) the data available to guide optimal management of this complex patient population to minimize complications regardless of the surgical approach taken.

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.

Contemporary incidence and risk factors for carotid artery disease in patients referred for coronary artery bypass surgery

BACKGROUND

In the past decade, there has been an increase in the amount of patients with medical co-morbidities referred for coronary artery bypass surgery (CABG). Significant carotid artery disease in patients undergoing CABG procedures increases the risk of neurological complications. We review the results of routine carotid screening in patients undergoing CABG to determine the contemporary incidence and risk factors for carotid artery disease.

METHODS

Between 2008 through 2010, 673 patients were referred for isolated coronary artery bypass surgery at a single institution. Patients were identified through a systematic review of The Department of Cardiothoracic Surgery Society of Thoracic Surgery Outcomes Database. A retrospective analysis of prospectively collected demographic, clinical data and outcomes were performed. All patients with screening preoperative carotid duplex were reviewed. We defined the degree of carotid disease as: none to mild stenosis (<50%), moderate stenosis (50-69%), severe stenosis (70-99%). Multivariate analysis was performed to identify risk factors.

RESULTS

559 (83%) patients underwent screening preoperative carotid ultrasonography prior to CABG. The incidence of carotid artery disease (>50% stenosis) was 36% with 18% unilateral moderate disease, 10% bilateral moderate and 8% severe disease. Risk factors associated with carotid artery disease included: advanced age, renal failure, previous stroke, peripheral vascular disease, left main coronary artery disease, and previous myocardial infarction.

CONCLUSIONS

There is a significant incidence of carotid artery stenosis in patients referred for CABG. Routine screening will identify patients with carotid artery disease and may reduce the risk of postoperative stroke.

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.