External Validation of Risk Prediction Models to Improve Selection of Patients for Carotid Endarterectomy

Higher long-term mortality in patients with positive preoperative stress test undergoing elective carotid revascularization with carotid endarterectomy compared to transfemoral carotid artery stenting or transcarotid revascularization

OBJECTIVE

This study compared outcomes in patients with and without preoperative stress testing undergoing carotid revascularization including carotid endarterectomy (CEA), transfemoral carotid artery stenting (TF-CAS), and transcarotid revascularization (TCAR).

METHODS

Patients in the Vascular Quality Initiative Vascular Implant Surveillance and Interventional Outcomes Network database who underwent elective carotid revascularization from 2016 to 2020 were included. Patients were analyzed by group based on whether they underwent cardiac stress testing within 2 years preceding revascularization without subsequent coronary intervention. Subset analysis was performed comparing outcomes between those with negative and positive results (evidence of ischemia or myocardial infarction [MI]). Outcomes of interest were postoperative MI/neurological events, 90-day readmission rates, and long-term mortality.

RESULTS

We analyzed 18,364 patients (78.8% CEA, 9.3% TF-CAS, and 11.9% TCAR). Of these, 35.8% underwent preoperative stress testing (37.4% of CEA patients, 27.5% of TF-CAS patients, and 31.9% of TCAR patients). Although comorbidities were significantly higher among patients undergoing CEA with a preoperative stress test compared with those without stress testing, the overall prevalence of comorbidities was higher among patients undergoing TF-CAS or TCAR, irrespective of preoperative stress test status. Compared with patients with a negative stress test, patients with a positive stress test undergoing any form of carotid revascularization had a significant increase in 90-day readmission rates (CEA 19.6% vs 15.8% [P = .003]; CAS 33.3% vs 18.6% [P < .001]; TCAR 25% vs 17.5% [P = .04]). No group demonstrated a difference in the incidence of in-hospital postoperative neurological events or congestive heart failure, but those undergoing CEA (but not CAS or TCAR) experienced a significant increase in-hospital postoperative MI (1.7% vs 0.6%; P < .001). In 3-year follow-up, those with a positive compared with negative stress test were more likely to undergo coronary artery bypass graft/percutaneous coronary intervention in the CEA (adjusted hazard ratio [HR], 1.87 [95% confidence interval (CI), 1.42-2.27]; P < .0001) and CAS groups (adjusted HR, 3.89 [95% CI, 1.77-8.57]; P < .01), but not the TCAR cohort. Notably, those undergoing CEA with a positive compared with negative stress test, but not CAS or TCAR, exhibited a 28% increase in mortality (adjusted HR, 1.28 [95% CI, 1.03-1.58]; P = .03) at 3 years. Conversely, those patients with a negative stress test compared with no stress test undergoing CEA experienced a 14% decrease in mortality at 3 years (adjusted HR, 0.86 [95% CI, 0.76-0.98]; P = .02); this mortality difference was not observed in similar stress test cohorts undergoing TF-CAS or TCAR.

CONCLUSIONS

Our study highlights that a positive stress test in appropriately selected, asymptomatic patients undergoing elective carotid revascularization can predict select perioperative and long-term cardiovascular outcomes. However, given the high follow-up mortality associated with those undergoing CEA for elective carotid revascularization, our findings call into question whether these patients should be offered optimal medical management and/or stenting preferentially.

Validity of E-PASS Score for Evaluating Perioperative Minor Complications Associated with Carotid Endarterectomy

Carotid endarterectomy (CEA) is conducted to reduce the risk of cerebral infarction; therefore, a low complication rate is highly required. To predict long-term morbidity and mortality, various scoring systems have been considered; nonetheless, a model that can be utilized to estimate nonmajor temporary complications and minor complications is currently lacking. To evaluate the occurrence rate of perioperative complications in various surgical domains, the E-PASS (Estimation of Physiological Ability and Surgical Stress) score is employed. This study was carried out to investigate the utility of the E-PASS score as a predictive factor for the risk of minor complications in patients undergoing CEA. The retrospective analysis was performed for 104 consecutive series of CEA procedures carried out at Otaru Municipal Hospital. The correlation between E-PASS and the rate of minor complications was examined. Sensitivity and specificity were used to construct a receiver operating characteristic curve, and the area under the curve (AUC) was calculated for accuracy. Postoperative minor complications occurred in eight cases (7.7%), including six vagal nerve injuries and two pneumonia cases. Three categorical data-preoperative risk score, surgical stress scores, and comprehensive risk score (CRS) -showed a good relationship with the postoperative minor complication. Among them, CRS presented the highest sensitivity and specificity, as indicated by an AUC of 0.68. The CRS cutoff value was calculated as -0.068, with a 1.7% postoperative minor complication rate for those lower than -0.068 and 14.0% for those higher than -0.068. The E-PASS score was effective for evaluating and predicting postoperative minor complications in patients with CEA procedures.

TCD-Guided management in carotid endarterectomy: a retrospective study

BACKGROUNDː: Stroke, primarily resulting from ischemic conditions, is the foremost cause of mortality and long-term impairment and is frequently associated with narrowing of the carotid arteries. Although carotid endarterectomy (CEA) is the treatment of choice, it carries the risk of cerebral ischemia and reduced blood flow. Transcranial Doppler (TCD) ultrasound offers a nonintrusive method to assess cerebral blood circulation during CEA, potentially enhancing surgical outcomes. The objective of this study was to assess the clinical utility and safety of TCD monitoring during CEA and to identify factors influencing postoperative complications. METHODS: This retrospective analysis included 158 CEA patients (from January 2021-August 2023) who underwent TCD monitoring and whose data were compared to historical standard care data. The primary outcomes were operation duration and artery occlusion time. Secondary outcomes included carotid shunt usage, seven-day postoperative complications, and six-month carotid artery patency. Logistic regression identified factors linked to adverse reactions, and a predictive model was evaluated with a receiver operating characteristic (ROC) curve. RESULTSː: Comparative analysis indicated significant reductions in both the duration of surgery (113.26 ± 7.29 min) and artery occlusion time (21.85 ± 2.92 min) for patients monitored with TCD (P < 0.001) and an increase in carotid shunt implementation (25% as opposed to traditional care). The observed postoperative complications were minor, with a nonsignificant trend that favored the use of TCD-monitored procedures (1% vs. historical rates). Factors such as patient age and plaque echogenicity were found to be predictive of postoperative issues, with plaque echogenicity emerging as a significant predictive factor (OR = 10.70, 95% CI: 2.14-202, P = 0.02) upon multivariate analysis. The predictive model exhibited high precision (AUC = 0.93). CONCLUSION: This retrospective evaluation suggested that TCD monitoring in the CEA may reduce procedural time and potentially decrease postoperative complications, supporting its use for personalized surgical planning.

Identification of patient characteristics that may improve procedure selection for the treatment of carotid stenosis

BACKGROUND

Carotid endarterectomy and carotid artery stenting are common procedures for the treatment of carotid artery stenosis. The aim of this study was to identify factors that modify the effect between type of treatment and outcome, and could thus be used to refine the selection of treatment procedure.

METHODS

All patients who underwent either carotid endarterectomy or carotid artery stenting between 2012 and 2018 in German hospitals were included. The analysis of effect modification was focused on baseline patient characteristics. The outcome was a composite of any stroke or death until discharge from hospital. For multivariable analyses, a generalized linear mixed regression model was used.

RESULTS

Some 221 282 patients were included, of whom 68% were male. In patients who underwent carotid endarterectomy or carotid artery stenting, the risk of any stroke or death was 2.3% and 3.7% respectively. Patient age was statistically significantly associated with a higher risk of a composite outcome of any stroke or death (main effect of age: adjusted OR 1.21 (95% c.i. 1.17 to 1.26), P < 0.001). The age effect was stronger in patients treated with carotid artery stenting (interaction effect: adjusted OR 1.29 (95% c.i. 1.20 to 1.38), P < 0.001). Statistically significant interaction effects were identified for side of treatment, ASA grade, contralateral degree of stenosis, and the time interval between the index event and treatment.

CONCLUSION

This analysis shows that carotid artery stenting may be particularly disadvantageous in older patients, in patients with right-sided stenosis, and in symptomatic patients treated within the first 2 days after the index event. In patients with contralateral occlusion, carotid artery stenting appears equivalent to carotid endarterectomy.

Recent advances and controversial issues in the optimal management of asymptomatic carotid stenosis

OBJECTIVE

The optimal management of patients with asymptomatic carotid stenosis (AsxCS) is enduringly controversial. We updated our 2021 Expert Review and Position Statement, focusing on recent advances in the diagnosis and management of patients with AsxCS.

METHODS

A systematic review of the literature was performed up to August 1, 2023, using PubMed/PubMed Central, EMBASE and Scopus. The following keywords were used in various combinations: "asymptomatic carotid stenosis," "carotid endarterectomy" (CEA), "carotid artery stenting" (CAS), and "transcarotid artery revascularization" (TCAR). Areas covered included (i) improvements in best medical treatment (BMT) for patients with AsxCS and declining stroke risk, (ii) technological advances in surgical/endovascular skills/techniques and outcomes, (iii) risk factors, clinical/imaging characteristics and risk prediction models for the identification of high-risk AsxCS patient subgroups, and (iv) the association between cognitive dysfunction and AsxCS.

RESULTS

BMT is essential for all patients with AsxCS, regardless of whether they will eventually be offered CEA, CAS, or TCAR. Specific patient subgroups at high risk for stroke despite BMT should be considered for a carotid revascularization procedure. These patients include those with severe (≥80%) AsxCS, transcranial Doppler-detected microemboli, plaque echolucency on Duplex ultrasound examination, silent infarcts on brain computed tomography or magnetic resonance angiography scans, decreased cerebrovascular reserve, increased size of juxtaluminal hypoechoic area, AsxCS progression, carotid plaque ulceration, and intraplaque hemorrhage. Treatment of patients with AsxCS should be individualized, taking into consideration individual patient preferences and needs, clinical and imaging characteristics, and cultural, ethnic, and social factors. Solid evidence supporting or refuting an association between AsxCS and cognitive dysfunction is lacking.

CONCLUSIONS

The optimal management of patients with AsxCS should include BMT for all individuals and a prophylactic carotid revascularization procedure (CEA, CAS, or TCAR) for some asymptomatic patient subgroups, additionally taking into consideration individual patient needs and preference, clinical and imaging characteristics, social and cultural factors, and the available stroke risk prediction models. Future studies should investigate the association between AsxCS with cognitive function and the role of carotid revascularization procedures in the progression or reversal of cognitive dysfunction.

Detection rates of asymptomatic carotid artery stenosis and atrial fibrillation by selective screening of patients without cardiovascular disease

BACKGROUND

Individuals with significant asymptomatic carotid artery stenosis (ACAS) and atrial fibrillation (AF) could benefit from specific interventions to prevent heart attack and stroke, but are often clinically 'silent'. We aimed to determine detection rate of ACAS and AF by screening, targeting a population at increased cardiovascular risk.

METHODS

Data on adults who attended voluntary and self-funded commercial screening clinics in the United States or the United Kingdom between 2008 and 2013 were used. The Atherosclerotic Cardiovascular Disease (ASCVD) risk equation was applied to each participants and detection rates of targeted screening for ≥50% ACAS and AF to those at highest risk of CVD was assessed.

RESULTS

Among 0.4 million individuals between 40 and 80 years, without CVD, 6191 (1.6%) had ACAS and 1026 (0.3%) had AF. Selective screening of participants with a predicted 10-year CVD risk of ≥20% identified 40% of ACAS cases, a prevalence of 3.7%, leading to a number needed to screen (NNS) of 27, as well as 39% of AF cases, a prevalence of 0.6%, with a NNS of 170. Selective screening of those with a predicted 10-year CVD risk of ≥15% identified 54% of ACAS cases, a prevalence of 3.3%, and an NNS of 31, as well as 51% of AF cases, a prevalence of 0.5%, with an NNS of 195.

CONCLUSIONS

Selective screening for ACAS and AF implemented in ASCVD risk assessment greatly reduces the NNS when compared with population-level screening with detection rates of ACAS and AF substantially greater in people at higher predicted CVD risk.

Carotid calcium burden derived from computed tomography angiography as a predictor of all-cause mortality after carotid endarterectomy

OBJECTIVE

Carotid endarterectomy (CEA) aims to reduce the risk of stroke in patients with atherosclerotic carotid disease. Preoperative risk assessments that predict complications are needed to optimize the care in this patient group. The current approach, namely relying solely on symptomatology and degree of stenosis, is outdated and calls for innovation. The Agatston calcium score was applied in several vascular specialties to assess cardiovascular risk profile but has been little studied in carotid surgery. It is hypothesized that a higher calcium burden at initial presentation equates to a worse prognosis attributable to an increased cerebrovascular and cardiovascular risk profile. The aim was to investigate the association between preoperative ipsilateral calcium score and postoperative all-cause mortality in patients undergoing CEA.

METHODS

This single-center retrospective cohort study included 89 patients who underwent CEA at a tertiary referral center between 2010 and 2018. Preoperative calcium scores were measured on contrast-enhanced computed tomography images with patient-specific Hounsfield thresholds at the level of the carotid bifurcation. The association between these calcium scores and all-cause mortality was analyzed using multivariable adjusted Cox proportional hazard analysis.

RESULTS

Cox proportional hazard analysis demonstrated a significant association between preoperative ipsilateral carotid calcium score and all-cause mortality (hazard ratio, 1.10; 95% confidence interval, 1.03-1.16; P = .003). After adjusting for age, preoperative estimated glomerular filtration rate, and diabetes mellitus, a significant association remained (hazard ratio, 1.07; 95% confidence interval, 1.00-1.15; P = .05).

CONCLUSIONS

A higher calcium burden was predictive of worse outcome, which might be explained by an overall poorer health status. These results highlight the potential of calcium measurements in combination with other traditional risk factors, for preoperative risk assessment and thus for improved patient education and care.

Performance of deep learning-based autodetection of arterial stenosis on head and neck CT angiography: an independent external validation study

PURPOSE

To externally validate the performance of automated stenosis detection on head and neck CT angiography (CTA) and investigate the impact factors using an independent bi-center dataset with digital subtraction angiography (DSA) as the ground truth.

MATERIAL AND METHODS

Patients who underwent head and neck CTA and DSA between January 2019 and December 2021 were retrospectively included. The degree of stenosis was automatically evaluated using CerebralDoc based on CTA. The performance of CerebralDoc across levels (per-patient, per-region, per-vessel, and per-segment) and thresholds (≥ 50%, ≥ 70%, and = 100%) was evaluated. Logistic regression was performed to identify independent factors associated with false negative results.

RESULTS

296 patients were analyzed. Specificity across levels and thresholds was high, exceeding 92%. The area under the curve ranged from poor (0.615, 95% CI: 0.544, 0.686; at the region-based analysis for stenosis ≥ 70%) to excellent (0.945, 95% CI: 0.905, 0.985; at the patient-based analysis for stenosis ≥ 50%). Sensitivity ranged from 0.714 (95% CI: 0.675, 0.750) at the segment-based analysis for stenosis ≥ 70% to 0.895 (95% CI: 0.849, 0.919) at the patient-based analysis for stenosis ≥ 50%. The multiple logistic regression analysis revealed that false negative results were primarily more likely to specific stenosis locations (particularly the M2 segment and skull base segment of the internal carotid artery) and occlusion.

CONCLUSIONS

CerebralDoc has the potential to automated stenosis detection on head and neck CTA, but further efforts are needed to optimize its performance.

Predictors of 30-day mortality using machine learning approach following carotid endarterectomy

BACKGROUND

Preoperative prognostication of 30-day mortality in patients with carotid endarterectomy (CEA) can optimize surgical risk stratification and guide the decision-making process to improve survival. This study aims to develop and validate a set of predictive variables of 30-day mortality following CEA.

METHODS

The patient cohort was identified from the American College of Surgeons National Surgical Quality Improvement Program (2005-2016). We performed logistic regression (enter, stepwise, and forward) and least absolute shrinkage and selection operator (LASSO) method for the selection of variables, which resulted in 28-candidate models. The final model was selected based upon clinical knowledge and numerical results.

RESULTS

Statistical analysis included 65,807 patients with 30-day mortality in 0.7% (n = 466) patients. The median age of our cohort was 71.0 years (range, 16-89 years). The model with 9 predictive factors which included age, body mass index, functional health status, American Society of Anesthesiologist grade, chronic obstructive pulmonary disorder, preoperative serum albumin, preoperative hematocrit, preoperative serum creatinine, and preoperative platelet count-performed best on discrimination, calibration, Brier score, and decision analysis to develop a machine learning algorithm. Logistic regression showed higher AUCs than LASSO across these different models. The predictive probability derived from the best model was converted into an open-accessible scoring system.

CONCLUSION

Machine learning algorithms show promising results for predicting 30-day mortality following CEA. These algorithms can be useful aids for counseling patients, assessing preoperative medical risks, and predicting survival after surgery.