Risk Factors Associated with Ipsilateral Ischemic Events Following Carotid Endarterectomy for Carotid Artery Stenosis

Temporal Trends and Contemporary Regional Variation in Management of Patients Undergoing Carotid Endarterectomy

INTRODUCTION

The purpose of this study is to investigate regional variation and temporal trends in seven quality metrics amongst CEA patients: discharge on antiplatelet after CEA; discharge on statin after CEA; protamine administration during CEA; patch placement at conventional CEA site; continued statin usage at the time of most recent follow-up; continued antiplatelet usage at the time of most recent follow-up; and smoking cessation at the time of long term follow up.

METHODS

There are 19 de-identified regions within the VQI database in the United States. Patients were placed into one of three temporal eras based on the time of their CEA: 2003-2008; 2009-2015; and 2016-2022. We first investigated temporal trends across the seven quality metrics for all regions combined on a national basis. The percentage of patients in each time era with the presence/absence of each metric was identified. Chi-squared testing was performed to confirm statistical significance of the differences across eras. Next, analysis was performed within each region and within each time metric. We separated out the 2016-2022 patients within each region to serve as the status of each metric application in the most modern era. We then compared the frequency of metric non-adherence in each region utilizing Chi-squared testing.

RESULTS

There was statistically significant improvement in achievement of all seven metrics between the initial 2003-2008 era and the modern 2016-2022 era. The most marked change in practice pattern was noted for lack of protamine usage at surgery (decreased from 48.7% to 25.9%), discharge home postoperatively without statin (decreased from 50.6% to 15.3%), and lack of statin usage confirmed at time of most recent long term follow up (decreased from 24% to 8.9%). Significant regional variation exists across all metrics (P < .01 for all). Lack of patch placement at the time of conventional endarterectomy ranges from 1.9% to 17.8% across regions in the modern era. Lack of protamine utilization ranges from 10.8% to 49.7%. Lack of antiplatelet and statin at the time of discharge varies from 5.5% to 8.2% and 4.8% to 14.4% respectively. Adherence to the various measures at the time of most recent follow up are more tightly aligned across regions with ranges of: 5.3% to 7.5% for lack of antiplatelet usage; 6.6% to 11.7% lack of statin utilization; and 13.3 to 15.4% for persistent smoking.

CONCLUSIONS

Prior studies and societal initiatives on CEA documenting the beneficial effects of patch angioplasty, protamine use at surgery, smoking cessation, antiplatelet utilization and statin compliance have positively impacted adherence to these measures over time. In the modern 2016-2022 era the widest regional variation is noted in patch placement, protamine utilization and discharge medications allowing individual geographic areas to identify areas for potential improvement via internal VQI administrative feedback.

Meta-Analysis Comparing the Frequency of Carotid Artery Stenosis in Patients With Atrial Fibrillation and Vice Versa

Atrial fibrillation (AF) and carotid stenosis (CS) can coexist and this association has been reported to result in a higher risk of stroke than attributed to either condition alone. Here we aimed to summarize the data on the association of CS and AF. MEDLINE and Embase were searched to identify all published studies providing relevant data through February 27, 2020. Random-effects meta-analysis method was used to pool estimates of prevalence. Heterogeneity was assessed by mean I-squared statistic. Forty-eight studies were included, 20 reporting on the prevalence of carotid disease in a pooled population of 49,070 AF patients, and 28 on the prevalence of AF in a total of 2,288,265 patients with carotid disease. The pooled prevalence of CS in AF patients was 12.4% (95% confidence interval [CI] 8.7 to 16.0, I² 93%; n = 3,919), ranging from 4.4% to 24.3%. The pooled prevalence of carotid plaque was 48.4% (95% CI 35.2 to 61.7, I² = 99%; n = 4292). The prevalence of AF in patients with CS was 9.3% (95% CI 8.7 to 10.0, I² 99%; n = 2,286,518), ranging from 3.6% to 10.0%. This prevalence was much higher (p <0.001) in patients undergoing carotid artery stenting (12.7%, 95% CI 11.3 to 14.02, I² 38.3%) compared with those undergoing carotid endarterectomy (6.9%, 95% CI 8.3 to 10.4, I² 94.1%). There was no difference in AF prevalence between patients with CS, with and without previous cerebrovascular event (p >0.05). In conclusion, AF and CS frequently coexist, with about one in ten patients with AF having CS, and vice versa. In addition, nonstenotic carotid disease is present in about half of AF patients. These findings have important implications for AF screening in patients with CS, stroke prevention, and the opportunities to intervene on common risk factors.

Presentation and outcomes of carotid endarterectomy in active smokers

OBJECTIVE

Smoking is a significant modifiable risk factor in the pathogenesis of carotid artery disease and has been shown to be a predictor of worse outcomes after vascular surgery. However, the effect of active smoking on outcomes of patients undergoing carotid endarterectomy is unknown. This study analyzed the outcomes of carotid endarterectomy by smoking status in a large national database.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program targeted carotid endarterectomy files (2011-2017) were reviewed. Patients were stratified according to smoking status, and outcomes were compared using propensity score matching (1:1) based on preoperative characteristics.

RESULTS

During the study period, 26,293 patients underwent carotid endarterectomy, with 19,282 (73.34%) nonsmokers and 7011 (26.66%) smokers. Smokers were more likely to be younger, to have chronic obstructive pulmonary disease, to have a symptomatic presentation, and to have higher anatomic risk (P < .05). Smokers were also more likely to have emergent surgery, to have general anesthesia, and to be reintubated (P < .05). After propensity matching, 5354 nonsmokers were matched with 5354 smokers who underwent carotid endarterectomy. Smokers were at significantly higher risk for death, with an odds ratio of 1.93 (confidence interval, 1.18-3.13).

CONCLUSIONS

Smokers are at increased risk for death after carotid endarterectomy compared with matched counterparts. Smoking should be considered an important risk factor for worse outcomes, and patients should be strongly counseled on the importance of smoking cessation before undergoing carotid endarterectomy.

Somatosensory Evoked Potentials and Electroencephalography during Carotid Endarterectomy Predict Late Stroke but not Death

BACKGROND

Late stroke and death rates are anticipated to be higher in patients undergoing carotid endarterectomy (CEA) compared with healthy counterparts. However, little is known regarding predictors other than the baseline comorbidities. We have recently shown that dual intraoperative somatosensory evoked potentials (SSEPs) and electroencephalography (EEG) monitoring improves the ability to predict perioperative strokes. We seek to determine if dual intraoperative monitoring (IOM) can further predict long-term strokes and death.

METHODS

Consecutive patients who underwent CEA under dual SSEP and EEG IOM between January 1, 2000 and December 31, 2010 were analyzed. Patients were divided in 2 groups, those with and those without IOM changes. IOM changes were classified as either occurring during carotid cross-clamp placement or at any time during the operation. End points were time to stroke and death. Log-rank tests and Cox regression analysis were used to identify predictors of postoperative stroke and death.

RESULTS

A total of 853 CEAs (mean age 70.6 ± 9.5 years, 58.7% male, 38.9% symptomatic) were performed during the study period with a mean clinical follow-up of 48 ± 38 months. One hundred seven patients (13.6%) had significant SSEP or EEG changes at the time of clamping, while considerably more patients (217, 25.4%) had SSEP and/or EEG changes recorded at any point during the procedure, including clamping. Baseline characteristics including rates of bilateral disease, statin use, and antiplatelet use were similar between groups. Female gender, symptomatic disease, and significant contralateral carotid stenosis were more frequent in the group with IOM changes. The overall stroke-free survival rate at 5 years was significantly higher in patients without IOM changes (94.7% vs. 88.2%, P < 0.05) and at 10 years (86.1% vs. 78.0%, P < 0.05). Despite differences in stroke-free survival, overall survival at 10 years was not different between groups (44.0% in patients with IOM changes vs. 42.8% in patients without, P = 0.7). Renal insufficiency (hazards ratio [HR] 2.13, P = 0.03), diabetes (HR 1.84, P = 005), and age > 80 at the time of operation (HR 3.24, P = 0.001) were significant predictors of late stroke, while statins were significantly protective (HR 0.55, P = 0.05). Controlling for these factors, IOM changes (HR 2.5, P = 0.004) were a strong predictor of long-term risk of stroke after CEA.

CONCLUSION

Intraoperative SSEP and/or EEG changes are predictive of late stroke but not death following CEA indicating a need for further elucidation and management of the underlying risk factors driving the elevated stroke risk in this subset of CEA patients.