Racial and Socioeconomic Disparities After Carotid Procedures.

BACKGROUND: Race has been associated with inferior outcomes after multiple procedures, but the association of socioeconomic status with procedures for cerebrovascular disease is not well established. MATERIALS AND METHODS: Elective carotid artery stenting (CAS) and carotid endarterectomy (CEA) procedures were identified in the National Inpatient Sample, 2012 to 2014. Median household income was estimated from patient ZIP codes. Chi-square and multivariable logistic regression analysis evaluated outcomes, accounting for age, race, gender, comorbidities, procedure, income, insurance, and hospital characteristics. RESULTS: We identified 234 825 carotid procedures (205 835 CEA and 28 990 CAS). Blacks and Hispanics were more likely to be among the lowest quartile income patients (LQIPs) compared to whites (53.5% and 38.7% vs 27.0%, respectively; P < .0002). Compared to highest income quartile patients, LQIP had lower rates of private insurance (16.3% vs 22.0%) and higher Medicaid use (4.7% vs 2.0%; all P < .0002). Lowest quartile income patients were more likely to receive CAS (odds ratio [OR] = 1.32, 95% confidence interval [CI]: 1.27-1.37), as were blacks and Hispanics (OR = 1.09, 95% CI: 1.02-1.26; OR = 1.31, 95% CI: 1.24-1.40, respectively). In multivariable regression, postoperative stroke was associated with LQIP, black race, and Hispanic ethnicity (OR = 1.16, 95% CI: 1.06-1.28; OR = 1.52, 95% CI: 1.33-1.73; OR = 1.43, 95% CI: 1.24-1.64, respectively). Subgroup analysis demonstrated that whites also had higher odds of stroke in the lower income quartile (OR = 1.2, 95% CI: 1.1-1.4). Mortality was associated with LQIP (OR = 1.6, 95% CI: 1.2-2.1), black race (OR = 1.8, 95% CI: 1.4-2.5), and CAS (OR = 1.3, 95% CI: 1.1-1.6). Length of stay in the lowest income quartile was longer than in patients with the highest income ( P < .0001). CONCLUSIONS: Race was associated with increased hospital mortality, postoperative stroke, and overall complications after carotid procedures. Lower income was significantly associated with increased stroke and mortality irrespective of race. Disparate utilization and outcomes for carotid procedures are multifactorial. Efforts to reduce disparities will need to focus on race and other socioeconomic factors.

The impact of race on outcomes after carotid endarterectomy in the United States.

OBJECTIVE: Black patients undergoing carotid endarterectomy (CEA) in the United States are more often symptomatic at presentation and have more comorbidities compared with white patients. However, the impact of race on outcomes after CEA is largely unknown. METHODS: We identified CEA patients in the Vascular Quality Initiative registry (2012-2017) and compared them by race (black vs white). All other nonwhite races (891 [1.4%]) and Hispanics (2222 [3.4%]) were excluded. We used multilevel logistic regression to account for differences in demographics and comorbidities. We assessed long-term survival using multivariable Cox regression. The primary outcome was perioperative stroke/death, with long-term survival as a secondary outcome. RESULTS: We included 57,622 CEA patients; 2909 (5.0%) were black, of whom 983 (34%) were symptomatic. Of the 54,713 white patients, 16,132 (30%) were symptomatic. Black patients, compared with white patients, had a higher vascular disease burden and were less likely to be operated on in a high-volume hospital or by a high-volume surgeon. In addition, black symptomatic patients, compared with white symptomatic patients, were more often operated on <2 weeks after the index neurologic symptom (47% vs 40%; P < .001). Perioperative stroke/death was comparable between black and white patients (symptomatic, 2.8% vs 2.2% [P = .2]; asymptomatic, 1.6% vs 1.3% [P = .2]), as was unadjusted survival at 3 years (93% vs 93%; P = .7). However, after adjustment, black patients did experience better long-term survival compared with white patients (hazard ratio, 0.8; 95% confidence interval, 0.7-0.9; P = .01). On multilevel logistic regression, race was not associated with perioperative stroke/death (odds ratio, 1.0; 95% confidence interval, 0.8-1.3; P = .98). CONCLUSIONS: Despite the greater prevalence of vascular risk factors in black patients and racial inequalities in surgical treatment, rates of perioperative stroke/death and unadjusted survival were similar between white and black patients. Moreover, black patients experienced better adjusted long-term survival after CEA.

Racial differences in statin adherence following hospital discharge for ischemic stroke.

OBJECTIVE: To compare nonadherence to statins in older black and white adults following an ischemic stroke. METHODS: We studied black and white adults ≥66 years of age with Medicare fee-for-service insurance coverage hospitalized for ischemic stroke from 2007 to 2012 who filled a statin prescription within 30 days following discharge. Nonadherence was defined as a proportion of days covered <80% in the 365 days following hospital discharge. In addition, we evaluated factors associated with nonadherence for white and black participants separately. RESULTS: Overall 2,763 beneficiaries met the inclusion criteria (13.5% black). Black adults were more likely than white adults to be nonadherent (49.7% vs 41.5%) even after adjustment for demographics, receipt of a low-income subsidy, and baseline comorbidities (adjusted relative risk [RR] 1.14, 95% confidence interval [CI] 1.01-1.29). Among white adults, receipt of a low-income subsidy (adjusted RR 1.13, 95% CI 1.02-1.26), history of coronary heart disease (adjusted RR 1.15, 95% CI 1.01-1.30), and discharge directly home following stroke hospitalization (adjusted RR 1.26, 95% CI 1.10-1.44) were associated with a higher risk of nonadherence. Among black adults, a 1-unit increase in the Charlson comorbidity index (adjusted RR 1.04, 95% CI 1.01-1.09), history of carotid artery disease (adjusted RR 2.38, 95% CI 1.08-5.25), and hospitalization during the 365 days prior to the index stroke (adjusted RR 1.34, 95% CI 1.01-1.78) were associated with nonadherence. CONCLUSIONS: Compared with white adults, black adults were more likely to be nonadherent to statins following hospitalization for ischemic stroke.

Distributions of Subclinical Cardiovascular Disease in a Socioeconomically and Racially Diverse Sample.

BACKGROUND AND PURPOSE: Differential subgroup vulnerability to subclinical cardiovascular disease is likely, and yet few, if any, studies have addressed interactive relations of age, sex, race, and socioeconomic status (SES) to these conditions to examine nuances of known health disparities. We examined distributions of carotid atherosclerosis and arterial stiffness in a socioeconomically diverse, biracial, urban sample. METHODS: Participants (n=2270) in the population-based HANDLS study (Healthy Aging in Neighborhoods of Diversity Across the Life Span; 30-64 years old, 44% men, 57% African American, 39% with household income <125% federal poverty threshold) underwent carotid intimal medial thickness (IMT) and pulse wave velocity assessment. RESULTS: In cross-sectional hierarchical regression analyses, interactive race×SES effects were identified for IMT and pulse wave velocity, such that high SES African Americans had significantly thicker IMTs and faster pulse wave velocities than all other subgroups (ie, low SES African Americans, low SES whites, and high SES whites). A race×sex effect was also identified for IMT, such that the IMT discrepancy between white men and women was more pronounced than the discrepancy between African American men and women. Finally, an SES×sex effect indicated that while IMTs of high SES and low SES men did not significantly differ, high SES women had marginally thicker IMTs than low SES women. CONCLUSIONS: High SES African Americans may be particularly vulnerable to subclinical cardiovascular diseases, placing them at enhanced risk for clinical cardiovascular diseases, including stroke. These findings suggest that male sex, low SES, and African American ancestry may represent imprecise generalizations as risk factors for subclinical cardiovascular disease.

Inflammatory Obesity Phenotypes, Gender Effects, and Subclinical Atherosclerosis in African Americans: The Jackson Heart Study.

OBJECTIVE: Reasons for variations in atherosclerotic burden among individuals with similar levels of obesity are poorly understood, especially in African Americans. This study examines whether high-sensitivity C-reactive protein (hsCRP) is useful for discriminating between benign and high-risk obesity phenotypes for subclinical atherosclerosis in African Americans. APPROACH AND RESULTS: Participants from the Jackson Heart Study (n=4682) were stratified into 4 phenotypes based on the presence of National Heart and Lung and Blood Institute definition of obesity or obesity-equivalent (body mass index ≥30 or body mass index 25-30 with waist circumference >102 cm in men and >88 cm in women) and inflammation by hsCRP ≥2 mg/L. Using multivariate regression models, we conducted cross-sectional analyses of the association between inflammatory obesity phenotypes and subclinical atherosclerosis determined by carotid intima-media thickness or coronary artery calcium scores. Sex-specific analyses were conducted given significant interaction for gender (P=0.03). The prevalence of obesity or equivalent was 65%, of which 30% did not have inflammation. Conversely, 37% of nonobese individuals had inflammation. Among nonobese men, hsCRP ≥2 mg/L identified a subset of individuals with higher carotid intima-media thickness (adjusted mean difference =0.05, 95% confidence interval 0.02, 0.08 mm) compared with their noninflammatory counterparts. Among obese men, hsCRP <2 mg/L identified a subset of individuals with lower coronary artery calcium compared with their inflammatory counterparts. Among women, associations between hsCRP and carotid intima-media thickness or coronary artery calcium were not found. CONCLUSIONS: In the largest African American population-based cohort to date, hsCRP was useful in identifying a subset of nonobese men with higher carotid intima-media thickness, but not in women. hsCRP did not identify a subset of obese individuals with less subclinical atherosclerosis.

Telomere length, endothelial activation and carotid atherosclerosis in black and white African patients with rheumatoid arthritis.

OBJECTIVES: Our objective was to examine associations of traditional and non-traditional cardiovascular risk factors with relative leukocyte telomere length and confounder adjusted relationships of relative telomere length with endothelial activation and carotid atherosclerosis in black and white African patients with rheumatoid arthritis (RA). METHODS: Relative telomere length of leukocyte DNA in whole blood was determined using quantitative RT-PCR in 205 (101 black) African patients with RA. RESULTS: In demographic characteristic adjusted analysis, relative telomere length tended to be larger in black compared to white patients (median (IQR)=0.54 (0.42-0.54) and 0.48 (0.37-0.60) (p=0.07), respectively). In black patients, waist circumference, systolic, diastolic and mean blood pressure were associated with relative telomere length (ß (SE)=-0.00270 (0.00114) (p=0.02), -0.00185 (0.00060) (p=0.003), -0.00243 (0.00112) (p=0.03) and -0.00225 (0.00075) (p=0.003), respectively); in white patients, age, anti-cyclic citrullinated antibody positivity, biologic agent use, a cholesterol-HDL cholesterol ratio of >4 and the number of major traditional risk factors were related to relative telomere length (ß (SE) =-0.00242 (0.00113) (p=0.03), 0.06629 (0.03374) (p=0.05), -0.09321 (0.04310) (p=0.03), 0.08225 (0.03420) (p=0.02) and 0.04046 (0.01719) (p=0.02), respectively). One SD increase in relative telomere length was associated with carotid plaque (OR (95% CI)=1.65 (0.99-2.75) (p=0.05)) and vascular cell adhesion molecule-1 concentrations (ß (SE)=-0.05031 (0.02480) (p=0.04)) in black and white patients, respectively. CONCLUSIONS: This study disclosed paradoxically direct relationships between relative telomere length and cardiovascular risk factors in white and atherosclerosis in black African RA patients. The role of relative telomere length in cardiovascular risk and its stratification in RA requires longitudinal investigation.

Shared and discrepant susceptibility for carotid artery and aortic arch calcification: A genetic association study.

Genome-wide association studies (GWASs) have identified several risk loci for coronary artery calcification. Four single-nucleotide polymorphisms (SNPs, rs1537370, rs1333049, rs2026458 and rs9349379) were associated with coronary artery calcification with P values less than 5 × 10(-8) in GWASs. It is unclear if these associations exist in other vascular beds. Thus, we evaluated the impacts of these four SNPs on carotid artery and aortic arch calcification in this study. Computed tomography was applied to quantify the calcification of carotid artery and aortic arch. 860 patients with stroke completed calcification quantification and genotype testing were included in data analysis. Each SNP was evaluated for the association with carotid artery calcification, and with aortic arch calcification using generalized linear model. Among the four tested SNPs, rs2026458 was associated with calcification in both carotid artery (ß = 0.31, 95% confidence interval [CI] 0.10-0.52, P = 0.003) and aortic arch (ß = 0.32, 95% CI 0.10-0.54, P = 0.004), while rs1333049 was only associated with carotid artery calcification (ß = 0.28, 95% CI 0.06-0.50, P = 0.011). In gender-stratified analyses, rs2026458 had significant impacts on carotid artery (P = 0.003) and aortic arch calcification (P = 0.008) in male, but not in female patients; while rs1537370 was significantly associated with carotid artery calcification in female (P = 0.013), but not in male patients. In conclusion, SNPs associated with coronary artery calcification may also increase the risk of calcification in other arteries such as carotid artery and aortic arch.

Race as a predictor of morbidity, mortality, and neurologic events after carotid endarterectomy.

OBJECTIVE: Racial disparities in the outcomes of patients undergoing carotid endarterectomy (CEA) have been reported. We sought to examine the contemporary relationship between race and outcomes and to report postdischarge events after CEA. METHODS: The American College of Surgeons National Surgical Quality Improvement Program Participant Use Data Files were reviewed to identify all CEAs performed from 2005 to 2010 by vascular surgeons. The influence of race on outcomes was examined. Multivariate analysis was performed using variables found to be significant on bivariate analysis. The primary outcomes were stroke and mortality. Secondary outcomes were other 30-day complications, including postdischarge events. RESULTS: CEA was performed on 29,114 white patients (95.7%) and on 1316 black patients (4.3%); the overall stroke and mortality rates were 1.65% and 0.7%, respectively. The stroke rate was 1.6% for whites and 2.5% blacks (P = .009). The 30-day mortality rate was 0.7% for whites and 1.4% for blacks (P = .002). There was a longer operating time (P < .001) and total length of stay (P < .001), more postoperative pneumonias (P = .049), unplanned intubations (P < .001), ventilator dependence (P < .001), cardiac arrests (P < .001), bleeding requiring transfusions (P = .024), and reoperations within 30 days (P = .021) among black patients. Multivariate logistic regression modeling identified black race as an independent risk factor for 30-day mortality (odds ratio, 1.9; P = .007). Black patients also had a greater proportion of in-hospital deaths than white patients (73.7% vs 43.1%; P = .01). There was no between-group difference in the rate of postdischarge strokes. Thirty-six percent of all strokes occurred after discharge at a mean of 8.3 days, and 54.3% of deaths occurred after discharge at a mean of 11 days. CONCLUSIONS: Black race is an independent risk factor for 30-day mortality after CEA. A significant proportion of strokes and deaths occur after discharge in both racial groups evaluated.

High prevalence of subclinical atherosclerosis by carotid ultrasound among Mexican Americans: discordance with 10-year risk assessment using the Framingham risk score.

BACKGROUND: Framingham risk scores (FRS) were validated in a mostly Caucasian population. Evaluation of subclinical atherosclerosis by carotid ultrasound may improve ascertainment of risk in nonwhite populations. This study aimed to evaluate carotid intima-media thickness (cIMT) and carotid plaquing among Mexican Americans, and to correlate these markers with coronary risk factors and the FRS. METHODS/RESULTS: Participants (n = 141) were drawn from the Cameron County Hispanic Cohort. Carotid artery ultrasound was performed and cIMT measured. Carotid plaque was defined as areas of thickening >50% of the thickness of the surrounding walls. Mean age was 53.1 ± 11.7 years (73.8% female). Most were overweight or obese (88.7%) and more than half (53.2%) had the metabolic syndrome. One third (34.8%) had abnormal carotid ultrasound findings (either cIMT ≥75th percentile for gender and age or presence of plaque). Among those with abnormal carotid ultrasound, the majority were classified as being at low 10-year risk for cardiovascular events. Carotid ultrasound reclassified nearly a third of the cohort as being at high risk. This discordance between 10-year FRS and carotid ultrasound was noted whether risk was assessed for hard coronary events or global risk. Concordance between FRS and carotid ultrasound findings was best when long-term (30-year) risk was assessed and no subject with an abnormal carotid ultrasound was categorized as low risk by the 30-year FRS algorithm. CONCLUSIONS: Integration of carotid ultrasound findings to coronary risk assessments and use of longer term prediction models may provide better risk assessment in this minority population, with earlier initiation of appropriate therapies.

Longitudinal assessment of fibrinogen in relation to subclinical cardiovascular disease: the CARDIA study.

OBJECTIVE: To examine the strength of the associations of fibrinogen with subclinical atherosclerosis in healthy persons. METHODS: A population-based, prospective, observational study of black and white men and women (Coronary Artery Risk Development in Young Adults [CARDIA]). Fibrinogen levels were measured at year 7 (ages 25-37, n = 2969), and again at year 20 (ages 38-50, n = 2832). Measures of subclinical atherosclerosis (coronary artery calcification [CAC] and carotid intimal-medial thickness [CIMT]) were recorded at year 20. RESULTS: Over the 13-year study interval (1992-1993 to 2005-2006), fibrinogen rose from a mean of 3.32 to 4.05 g L(-1). After adjusting for age, gender and race, fibrinogen was positively associated with greater incidence of CAC and increased CIMT cross-sectionally as well as after 13 years of follow-up (all P-trend < 0.001). After further adjustment for field center, BMI, smoking, education, systolic blood pressure, diabetes, antihypertensive medication use, total and HDL cholesterol, and CRP, significant positive relationships between fibrinogen and incidence of CAC remained for the total cohort longitudinally (P-trend = 0.037), but not cross-sectionally (P-trend = 0.147). CONCLUSION: This 13-year study demonstrates that higher levels of fibrinogen during young adulthood are positively associated with incidence of CAC and increased CIMT in middle-age, but the strength of the association declines with increasing age.

Life-course socioeconomic positions and subclinical atherosclerosis in the multi-ethnic study of atherosclerosis.

A major limitation of past work on the social patterning of atherosclerosis has been the reliance on measures of neighborhood or individual-level socioeconomic position (SEP) assessed at a single point in time in adulthood. Risk of chronic disease is thought to accumulate throughout the life-course, so the use of a measure for a single point in time may result in inaccurate estimates of the social patterning of subclinical disease. Using data from the US Multi-Ethnic Study of Atherosclerosis (MESA), we examined the relation between childhood SEP [CSEP] (father or caretaker's education), adulthood SEP [ASEP] (a summary score of income, education, and wealth), and 20-year average exposure to neighborhood poverty [NSEP] (residential addresses geocoded and linked to census data) and the prevalence of subclinical atherosclerosis, as assessed by common carotid intimal-medial thickness (IMT) in mid to late adulthood. Participants were 45-84 years of age at baseline and were sampled from six study sites in the United States. After adjustment for age, CSEP and ASEP were both inversely and independently associated with IMT in men. All three indicators CSEP, ASEP, and NSEP were inversely and independently associated with IMT in women. Associations were somewhat reduced after adjustment for cardiovascular risk factors, suggesting that these factors may play a mediating role. There was evidence of heterogeneity in effects of NSEP by gender, and in the effects of ASEP and NSEP by race/ethnicity. Our results contribute to the growing body of work that shows that SEP at multiple points in the life-course, and at the individual and neighborhood level, contributes to the development of atherosclerosis.

Associations of acculturation and socioeconomic status with subclinical cardiovascular disease in the multi-ethnic study of atherosclerosis.

OBJECTIVES: We assessed whether markers of acculturation (birthplace and number of US generations) and socioeconomic status (SES) are associated with markers of subclinical cardiovascular disease-carotid artery plaque, internal carotid intima-media thickness, and albuminuria-in 4 racial/ethnic groups. METHODS: With data from the Multi-Ethnic Study of Atherosclerosis (n = 6716 participants aged 45-84 years) and race-specific binomial regression models, we computed prevalence ratios adjusted for demographics and traditional cardiovascular risk factors. RESULTS: The adjusted US- to foreign-born prevalence ratio for carotid plaque was 1.20 (99% confidence interval [CI] = 0.97, 1.39) among Whites, 1.91 (99% CI = 0.94, 2.94) among Chinese, 1.62 (99% CI = 1.28, 2.06) among Blacks, and 1.23 (99% CI = 1.15, 1.31) among Hispanics. Greater carotid plaque prevalence was found among Whites, Blacks, and Hispanics with a greater number of generations with US residence (P < .001) and among Whites with less education and among Blacks with lower incomes. Similar associations were observed with intima-media thickness. There was also evidence of an inverse association between albuminuria and SES among Whites and Hispanics. CONCLUSIONS: Greater US acculturation and lower SES were associated with a higher prevalence of carotid plaque and greater intima-media thickness but not with albuminuria. Maintenance of healthful habits among recent immigrants should be encouraged.

Socioeconomic differences in progression of carotid intima-media thickness in the Atherosclerosis Risk in Communities study.

OBJECTIVE: To examine the association of socioeconomic factors with progression of carotid intimal-medial thickness (IMT) in middle-aged adults. Cross-sectional associations of IMT with socioeconomic status (SES) have been demonstrated in middle-aged cohorts. It is unclear whether these factors are associated with progression of IMT. METHODS AND RESULTS: We examined IMT progression over 9 years among a middle-aged cohort of 12,085 black and white subjects free of cardiovascular disease recruited from 4 US sites participating in the Atherosclerosis Risk in Communities (ARIC) study. Baseline IMT was inversely related to SES among whites and blacks. Repeated measures regression models of IMT progression showed moderate inverse relationships of IMT progression with income in whites so that the difference in 5-year IMT progression rates between the highest and lowest categories was -11.5 microm (CI, -17.4 to -5.6). In contrast, among blacks, this gradient is reversed, with an 11.1 microm (CI, -0.1 to 22.3) difference in 5-year progression between highest and lowest income category. Generally, similar patterns were observed for other socioeconomic indicators. Patterns were not accounted for by baseline cardiovascular risk factors. CONCLUSIONS: SES is inversely related to IMT progression in middle-aged whites but positively related to IMT progression among middle-aged blacks. These differences do not appear to be attributable to selective attrition or higher IMT among blacks at baseline.

Differences in risk factors, atherosclerosis, and cardiovascular disease between ethnic groups in Canada: the Study of Health Assessment and Risk in Ethnic groups (SHARE)

BACKGROUND: Cardiovascular disease rates vary greatly between ethnic groups in Canada. To establish whether this variation can be explained by differences in disease risk factors and subclinical atherosclerosis, we undertook a population-based study of three ethnic groups in Canada: South Asians, Chinese, and Europeans. METHODS: 985 participants were recruited from three cities (Hamilton, Toronto, and Edmonton) by stratified random sampling. Clinical cardiovascular disease was defined by history or electrocardiographic findings. Carotid atherosclerosis was measured with B-mode ultrasonography. Conventional (smoking, hypertension, diabetes, raised cholesterol) and novel risk factors (markers of a prothrombotic state) were measured. FINDINGS: Within each ethnic group and overall, the degree of carotid atherosclerosis was associated with a higher prevalence of cardiovascular disease. South Asians had the highest prevalence of this condition compared with Europeans and Chinese (11%, 5%, and 2%, respectively, p=0.0004). Despite this finding, Europeans had more atherosclerosis (mean of the maximum intimal medial thickness 0.75 [0.16] mm) than South Asians (0.72 [0.15] mm), and Chinese (0.69 [0.16] mm). South Asians had an increased prevalence of glucose intolerance, higher total and LDL cholesterol, higher triglycerides, and lower HDL cholesterol, and much greater abnormalities in novel risk factors including higher concentrations of fibrinogen, homocysteine, lipoprotein (a), and plasminogen activator inhibitor-1. INTERPRETATION: Although there are differences in conventional and novel risk factors between ethnic groups, this variation and the degree of atherosclerosis only partly explains the higher rates of cardiovascular disease among South Asians compared with Europeans and Chinese. The increased risk of cardiovascular events could be due to factors affecting plaque rupture, the interaction between prothrombotic factors and atherosclerosis, or as yet undiscovered risk factors.