Race Differences in High-Grade Carotid Artery Stenosis

William M. Feinberg Lecture: Asymptomatic Carotid Stenosis: Current and Future Considerations

Asymptomatic high-grade carotid stenosis is an important therapeutic target for stroke prevention. For decades, the ACAS (Asymptomatic Carotid Atherosclerosis Study) and ACST (Asymptomatic Carotid Surgery Trial) trials provided most of the evidence supporting endarterectomy for patients with asymptomatic high-grade stenosis who were otherwise good candidates for surgery. Since then, transfemoral/transradial carotid stenting and transcarotid artery revascularization have emerged as alternatives to endarterectomy for revascularization. Advances in treatments against atherosclerosis have driven down the rates of stroke in patients managed without revascularization. SPACE-2 (Stent-Protected Angioplasty Versus Carotid Endarterectomy-2), a trial that included endarterectomy, stenting, and medical arms, failed to detect significant differences in stroke rates among treatment groups, but the study was stopped well short of its recruitment goal. CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial) will be able to clarify whether revascularization by stenting or endarterectomy remains efficacious under conditions of intensive medical management. Transcarotid artery revascularization has a favorable periprocedural risk profile, but randomized trials comparing it to intensive medical management are lacking. Features like intraplaque hemorrhage on MRI and echolucency on B-mode ultrasonography can identify patients at higher risk of stroke with asymptomatic stenosis. High-grade stenosis with poor collaterals can cause hemispheric hypoperfusion, and unstable plaque can cause microemboli, both of which may be treatable risk factors for cognitive impairment. Evidence that there are patients with carotid stenosis who benefit cognitively from revascularization is presently lacking. New risk factors are emerging, like exposure to microplastics and nanoplastics. Strategies to limit exposure will be important without specific medical therapies.

Cognitive impairment in asymptomatic carotid artery stenosis is associated with abnormal segments in the Circle of Willis

OBJECTIVE

Our group has previously demonstrated that patients with asymptomatic carotid artery stenosis (ACAS) demonstrate cognitive impairment. One proposed mechanism for cognitive impairment in patients with ACAS is cerebral hypoperfusion due to flow-restriction. We tested whether the combination of a high-grade carotid stenosis and inadequate cross-collateralization in the Circle of Willis (CoW) resulted in worsened cognitive impairment.

METHODS

Twenty-four patients with high-grade (≥70% diameter-reducing) ACAS underwent carotid duplex ultrasound, cognitive assessment, and 3D time-of-flight magnetic resonance angiography. The cognitive battery consisted of nine neuropsychological tests assessing four cognitive domains: learning and recall, attention and working memory, motor and processing speed, and executive function. Raw cognitive scores were converted into standardized T-scores. A structured interpretation of the magnetic resonance angiography images was performed with each segment of the CoW categorized as being either normal or abnormal. Abnormal segments of the CoW were defined as segments characterized as narrowed or occluded due to congenital aplasia or hypoplasia, or acquired atherosclerotic stenosis or occlusion. Linear regression was used to estimate the association between the number of abnormal segments in the CoW, and individual cognitive domain scores. Significance was set to P < .05.

RESULTS

The mean age of the patients was 66.1 ± 9.6 years, and 79.2% (n = 19) were male. A significant negative association was found between the number of abnormal segments in the CoW and cognitive scores in the learning and recall (β = -6.5; P = .01), and attention and working memory (β = -7.0; P = .02) domains. There was a trend suggesting a negative association in the motor and processing speed (β = -2.4; P = .35) and executive function (β = -4.5; P = .06) domains that did not reach significance.

CONCLUSIONS

In patients with high-grade ACAS, the concomitant presence of increasing occlusive disease in the CoW correlates with worse cognitive function. This association was significant in the learning and recall and attention and working memory domains. Although motor and processing speed and executive function also declined numerically with increasing abnormal segments in the CoW, the relationship was not significant. Since flow restriction at a carotid stenosis compounded by inadequate collateral compensation across a diseased CoW worsens cerebral perfusion, our findings support the hypothesis that cerebral hypoperfusion underlies the observed cognitive impairment in patients with ACAS.

Comparative assessment of racial disparity in 30-day outcomes for Asian Americans undergoing carotid endarterectomy

OBJECTIVE

Carotid endarterectomy (CEA) is an effective treatment for carotid stenosis. All previous studies on racial disparity of CEA outcomes omitted Asian Americans. This study aimed to address this gap by investigating racial disparities in 30-day outcomes following CEA among Asian Americans.

METHODS

Asian American and Caucasian patients who underwent CEA were identified in the American College of Surgeons National Surgical Quality Improvement Program targeted database from 2011 to 2021. Patients with age less than 18 years old were excluded. Patients with symptomatic and asymptomatic carotid stenosis were examined separately. A 1:5 propensity-score matching was used to address preoperative differences. Thirty perioperative outcomes were assessed.

RESULTS

There were 380 Asian Americans (2.27%) and 13,250 Caucasians (79.18%) with symptomatic carotid stenosis who underwent CEA. Also, 289 Asian Americans (1.40%) and 18,257 Caucasians (88.14%) with asymptomatic carotid stenosis had CEA. Asian Americans undergoing CEA presented with higher comorbid burdens and more severe symptomology. Also, asymptomatic Asian Americans were more likely to undergo surgeries for mild stenosis (<50%), which is not in line with practice guidelines. After 1:5 propensity-matching, all symptomatic Asian Americans were matched to 1550 Caucasian patients, and all asymptomatic Asian Americans were matched to 1445 Caucasians; preoperative differences were addressed. Asian Americans exhibited low overall 30-day mortality (symptomatic, 1.61%; asymptomatic, 0.35%) and stroke (symptomatic, 2.26%; asymptomatic, 0.69%). All perioperative outcomes were comparable to Caucasians, with the exception that Asian Americans experienced longer operation times.

CONCLUSIONS

Evidence suggested that Asian Americans with asymptomatic stenosis were underrepresented in CEA. After propensity-score matching, Asian Americans demonstrated comparable 30-day outcomes to Caucasians. These suggest that, when afforded equal access to quality health care, CEA serves as an effective treatment for carotid stenosis among Asian Americans. Therefore, efforts may be aimed at addressing health care access, potentially in the screening for asymptomatic carotid stenosis in Asian Americans. This would ensure they have equitable benefits from CEA. Nevertheless, the exact preoperative differences and long-term CEA outcomes in Asian Americans should warrant further examination in future studies.

Circulating Sex-Specific Markers of Plaque Instability in Women and Men With Severe Carotid Atherosclerosis

BACKGROUND

Sex-specific differences in plaque composition and instability underscore the need to explore circulating markers for better prediction of high-risk plaques. This cross-sectional study aims to (1) investigate differences in lipid, immune, and adipokine circulating profiles between men and women with stable versus unstable plaques and (2) identify circulating markers that can better classify men and women according to plaque instability.

METHODS

Preoperative blood samples and plaque specimens were collected from consecutive men and women with carotid artery stenosis ≥50% and who underwent a carotid endarterectomy between 2009 and 2018. Adipokine, lipid, and immune profiling was conducted. Plaque stability was determined by gold-standard histological classifications. Statistical analyses, including χ2, ANOVA, Kruskal-Wallis, and logistic regression, assessed differences in plaque features and blood parameters between men and women with stable and unstable plaques.

RESULTS

Of 470 recruited patients (aged 70.8±9.2 years), the final study analyses included 317 men and 143 women (aged 71.0±9.0 years). Men exhibited more unstable plaques (P<0.001), characterized by increased plaque hemorrhage, larger lipid core, and inflammation (P<0.001), along with less favorable circulating profiles. Antagonistic interactions between sex and white blood cell (WBC) counts, basophil-to-WBC ratio, and platelet counts influenced plaque instability. In men, low WBC counts, high monocyte-to-WBC ratio, low basophil-to-WBC ratio, and high LDL-C (low-density lipoprotein cholesterol) levels were associated with greater plaque instability (odds ratio, 0.827 [95% CI, 0.713-0.926], 1.158 [95% CI, 1.027-1.305], 0.495 [95% CI, 0.281-0.871], and 1.564 [95% CI, 1.001-2.443], respectively) and more unstable features (ie, inflammation, foam cells, and neovascularization). In women, a high basophil-to-WBC ratio was associated with greater plaque instability (3.142 [95% CI, 1.220-8.093]), hemorrhage, and thrombosis, while a high molecular weight-to-total adiponectin ratio was associated with decreased instability (0.014 [95% CI, 0.000-0.646]) and inflammation.

CONCLUSIONS

Our findings demonstrated sex-specific differences, with women displaying more stable plaque phenotypes and favorable circulating profiles compared with men. This proof-of-concept study was also designed as the key first step in exploring novel sex-specific associations between circulating lipid, immune, and adipokine profiles and carotid plaque instability.

Social Determinants of Health Framework to Identify and Reduce Barriers to Imaging in Marginalized Communities

Social determinants of health (SDOH) are conditions influencing individuals' health based on their environment of birth, living, working, and aging. Addressing SDOH is crucial for promoting health equity and reducing health outcome disparities. For conditions such as stroke and cancer screening where imaging is central to diagnosis and management, access to high-quality medical imaging is necessary. This article applies a previously described structural framework characterizing the impact of SDOH on patients who require imaging for their clinical indications. SDOH factors can be broadly categorized into five sectors: economic stability, education access and quality, neighborhood and built environment, social and community context, and health care access and quality. As patients navigate the health care system, they experience barriers at each step, which are significantly influenced by SDOH factors. Marginalized communities are prone to disparities due to the inability to complete the required diagnostic or screening imaging work-up. This article highlights SDOH that disproportionately affect marginalized communities, using stroke and cancer as examples of disease processes where imaging is needed for care. Potential strategies to mitigate these disparities include dedicating resources for clinical care coordinators, transportation, language assistance, and financial hardship subsidies. Last, various national and international health initiatives are tackling SDOH and fostering health equity.

Socioeconomic status fails to account for worse outcomes in non-Hispanic black patients undergoing carotid revascularization

OBJECTIVE

Previous studies have reported an association of Black race with worse carotid revascularization outcomes, but rarely include socioeconomic status as a confounding covariate. We aimed to assess the association of race and ethnicity with in-hospital and long-term outcomes following carotid revascularization before and after accounting for socioeconomic status.

METHODS

We identified non-Hispanic Black and non-Hispanic white patients who underwent carotid endarterectomy, transfemoral carotid stenting, or transcarotid artery revascularization between 2003 and 2022 in the Vascular Quality Initiative. Primary outcomes were in-hospital stroke/death and long-term stroke/death. Multivariable logistic regression and Cox proportional hazards models were used to assess the association of race with perioperative and long-term outcomes after adjusting for baseline characteristics using a sequential model approach without and with consideration of Area Deprivation Index (ADI), a validated composite marker of socioeconomic status.

RESULTS

Of 201,395 patients, 5.1% (n = 10,195) were non-Hispanic Black, and 94.9% (n = 191,200) were non-Hispanic white. Mean follow-up time was 3.4±0.01 years. A disproportionately high percentage of Black patients were living in more socioeconomically deprived neighborhoods relative to their white counterparts (67.5% vs 54.2%; P < .001). After adjusting for demographic, comorbidity, and disease characteristics, Black race was associated with greater odds of in-hospital (adjusted odds ratio [aOR], 1.24; 95% confidence interval [CI], 1.10-1.40) and long-term stroke/death (adjusted hazard ratio [aHR], 1.13; 95% CI, 1.04-1.23). These associations did not substantially change after additionally adjusting for ADI; Black race was persistently associated with greater odds of in-hospital (aOR, 1.23; 95% CI, 1.09-1.39) and long-term stroke/death (aHR, 1.12; 95% CI, 1.03-1.21). Patients living in the most deprived neighborhoods were at greater risk of long-term stroke/death compared with patients living in the least deprived neighborhoods (aHR, 1.19; 95% CI, 1.05-1.35).

CONCLUSIONS

Non-Hispanic Black race is associated with worse in-hospital and long-term outcomes following carotid revascularization despite accounting for neighborhood socioeconomic deprivation. There appears to be unrecognized gaps in care that prevent Black patients from experiencing equitable outcomes following carotid artery revascularization.

Combined Association of Novel and Traditional Inflammatory Biomarkers With Carotid Artery Plaque: GlycA Versus C-Reactive Protein (ELSA-Brasil)

Elevated levels of glycoprotein acetylation (GlycA) and C-reactive protein (CRP) have been associated with carotid artery plaque (CAP). However, it is not yet established if elevations in both inflammatory biomarkers provide incremental association with CAP. This study aimed evaluate the cross-sectional association of high CRP and GlycA with CAP at baseline participants from the ELSA-Brasil adult cohort. Participants with information on CRP, GlycA, and CAP with neither previous cardiovascular disease nor CRP >10 mg/L were included. High GlycA and CRP were defined as values within upper quintile and >3 mg/L, respectively. Participants were classified into 4 groups: 1. nonelevated CRP/GlycA (reference group); 2. elevated CRP alone; 3. elevated GlycA alone; and 4. both elevated. The analysis included 4,126 participants with median age of 50 years-old, being 54.2% of women. Prevalence of CAP was 36.1%. Participants with high CRP had the highest frequency of obesity, whereas participants with high GlycA presented higher cardiovascular risk factor burden and were more likely to have CAP than the reference group (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.11 to 1.73), persisting after multivariable adjustment (OR 1.37, 95% CI 1.02 to 1.83). Participants with both elevated CRP and GlycA were more likely to have CAP in crude (OR 1.35, 95% CI 1.10 to 1.65) but not in adjusted models. The findings suggest potential different biologic pathways between inflammation and carotid atherosclerosis: high GlycA was associated with CAP whereas high CRP was more associated with obesity.

Long non-coding RNA RMST serves as a diagnostic biomarker in patients with carotid artery stenosis and predicts the occurrence of cerebral ischemic event: A retrospective study

OBJECTIVES

The purpose of this retrospective study is to explore the diagnostic and prognostic roles of serum RMST in carotid artery stenosis (CAS).

METHODS

Serum levels of RMST were detected in CAS patients, and the relationship between degree of carotid stenosis and RMST levels was analyzed. The ROC curve was drawn to evaluate RMST value in predicting the risk of CAS. Then, all CAS patients received a 5-year follow-up. K-M curve was used to analyze the significance of RMST on prognosis of CAS patients. Multi-factor cox logistic regression analysis was conducted to evaluate independent factors for outcome of CAS patients.

RESULTS

An increased RMST expression was certified in CAS patients when compared with healthy controls. The increase of serum RMST expression was related to high degree of carotid stenosis. In addition, serum RMST was a possible diagnosis and an independent influencing factor of prognosis in patients with CAS.

CONCLUSIONS

Raised serum RMST level was found in patients with CAS. Detecting RMST expression levels was of high value for predicting the occurrence and outcomes in CAS.

Association between carotid intima-media thickness and cognitive decline differs by race

INTRODUCTION

Common carotid intima-media thickness (cIMT) is a marker of subclinical atherosclerosis and is associated with cognitive decline. Although carotid atherosclerosis is more frequent in White than in Black participants, little is known whether race modifies the association between cIMT and cognitive decline.

METHODS

In this longitudinal analysis of the ELSA-Brasil, we assessed cIMT using ultrasound and cognitive performance using different domain tests. We used linear mixed models, interaction analysis, and race stratified analyses.

RESULTS

Baseline high IMT values were associated with memory (p < 0.001), verbal fluency (p < 0.001), TMT-B (p < 0.001)), and global cognitive decline (p < 0.001). Race was an effect modifier in the association between IMT and global cognitive decline (0.043), with stronger association in White (p < 0.001) than in Black (p = 0.009) participants.

DISCUSSION

Baseline IMT was associated with global and domain-specific cognitive decline and race modified this relationship, with stronger associations in White participants.

HIGHLIGHTS

Carotid intima-media thickness (cIMT) was associated with cognitive decline. cIMT and cognitive decline association was stronger in White than in Black participants. We used inverse probability weighting to address attrition bias.

Provider care segregation and hospital-region racial disparities for carotid interventions in the USA

BACKGROUND

Reasons for racial disparities in the utilization and outcomes of carotid interventions (carotid endarterectomy (CEA) and carotid artery stenting (CAS)) are not well understood, especially segregation of care associated with carotid intervention. We examined patterns of geographic and provider care segregation in carotid interventions and outcomes.

METHOD

We used de-identified Medicare datasets to identify CEA and CAS interventions between January 1, 2016 and December 31, 2019 using validated ICD-10 codes. For patients who underwent carotid intervention, we calculated (1) the proportion of White patients at the hospital, (2) the proportional difference in the proportion of White patients between hospital patients and the county, and (3) provider care segregation by the dissimilarity index for carotid intervention cases. We examined associations between measures of segregation and outcomes.

RESULTS

Despite higher proportions of Black patients in counties with hospitals that provide carotid intervention, lower proportions of Black patients received intervention. The difference in the proportion of White patients comparing CEA patients to the county race distribution was 0.143 (SD 0.297) at the hospital level (for CAS, 0.174 (0.315)). The dissimilarity index for CEA providers was high, with mean (SD) 0.387 (0.274) averaged across all hospitals and higher among CAS providers at 0.472 (0.288). Black patients receiving CEA and CAS (compared with Whites) had reduced odds of discharge home. Better outcomes (inpatient mortality and 30-day mortality) were independently associated with higher proportion of White CAS patients.

CONCLUSION

In this national study with contemporary data on carotid intervention, we found evidence for segregation of care of both CEA and CAS.

Association between Race and Perioperative Outcomes after Carotid Endarterectomy for Asymptomatic Carotid Artery Stenosis in NSQIP

BACKGROUND

Previous studies have documented that Black patients have worse outcomes after lower extremity revascularization procedures compared with White patients. However, the association of race on carotid endarterectomy (CEA) outcomes is not well described. The aim of this study was to compare perioperative outcomes of CEA for Black vs White patients with asymptomatic carotid artery stenosis.

STUDY DESIGN

All patients who underwent CEA for asymptomatic carotid stenosis in the ACS-NSQIP targeted vascular database (2011-2019) were included. Perioperative (30-day) outcomes were compared for Black vs White patients using multivariable logistic regression adjusting for age/sex, comorbidities, and disease characteristics.

RESULTS

Of 16,764 asymptomatic CEA patients, 95.2% (N = 15,960) were White and 4.8% (N = 804) were Black. Black patients were slightly younger (mean age 71.4 ± 0.1 vs 69.9 ± 0.3 years, P < 0.001) and more frequently had high-grade carotid artery stenosis compared to White patients (79.5% vs 74.0%, p = 0.001). Comorbidities including hypertension, diabetes, kidney disease, congestive heart failure, and coronary artery disease were all more prevalent among Black patients (p ≤ 0.01). Crude perioperative stroke (2.4% vs 1.3%, p = 0.007) and stroke/death (2.6% vs 1.4%, p = 0.003) were higher for Black patients, but myocardial infarction (1.7% vs 1.5%, p = 0.67) and death (0.4% vs 0.2%, p = 0.12) were similar. After adjusting for baseline differences between groups, the risk of perioperative stroke (odds ratio 1.66, 95% CI 1.01 to 2.73) and stroke/death (odds ratio 1.75, 95% CI 1.10 to 2.81) remained significantly higher for Black patients compared with White patients.

CONCLUSIONS

Black patients undergoing CEA for asymptomatic carotid artery stenosis had more severe stenosis, more comorbidities, and worse perioperative outcomes compared to White patients. Overall, our data suggest substantial differences in the treatment and outcomes of asymptomatic carotid artery stenosis based on race.