Disparities in stroke incidence contributing to disparities in stroke mortality

Fair prediction of 2-year stroke risk in patients with atrial fibrillation

OBJECTIVE

This study aims to develop machine learning models that provide both accurate and equitable predictions of 2-year stroke risk for patients with atrial fibrillation across diverse racial groups.

MATERIALS AND METHODS

Our study utilized structured electronic health records (EHR) data from the All of Us Research Program. Machine learning models (LightGBM) were utilized to capture the relations between stroke risks and the predictors used by the widely recognized CHADS2 and CHA2DS2-VASc scores. We mitigated the racial disparity by creating a representative tuning set, customizing tuning criteria, and setting binary thresholds separately for subgroups. We constructed a hold-out test set that not only supports temporal validation but also includes a larger proportion of Black/African Americans for fairness validation.

RESULTS

Compared to the original CHADS2 and CHA2DS2-VASc scores, significant improvements were achieved by modeling their predictors using machine learning models (Area Under the Receiver Operating Characteristic curve from near 0.70 to above 0.80). Furthermore, applying our disparity mitigation strategies can effectively enhance model fairness compared to the conventional cross-validation approach.

DISCUSSION

Modeling CHADS2 and CHA2DS2-VASc risk factors with LightGBM and our disparity mitigation strategies achieved decent discriminative performance and excellent fairness performance. In addition, this approach can provide a complete interpretation of each predictor. These highlight its potential utility in clinical practice.

CONCLUSIONS

Our research presents a practical example of addressing clinical challenges through the All of Us Research Program data. The disparity mitigation framework we proposed is adaptable across various models and data modalities, demonstrating broad potential in clinical informatics.

Analysis of eligibility criteria in Alzheimer's and related dementias clinical trials

Overly restrictive clinical trial eligibility criteria can reduce generalizability, slow enrollment, and disproportionately exclude historically underrepresented populations. The eligibility criteria for 196 Alzheimer's Disease and Related Dementias (AD/ADRD) trials funded by the National Institute on Aging were analyzed to identify common criteria and their potential to disproportionately exclude participants by race/ethnicity. The trials were categorized by type (48 Phase I/II pharmacological, 7 Phase III/IV pharmacological, 128 non-pharmacological, 7 diagnostic, and 6 neuropsychiatric) and target population (51 AD/ADRD, 58 Mild Cognitive Impairment, 25 at-risk, and 62 cognitively normal). Eligibility criteria were coded into the following categories: Medical, Neurologic, Psychiatric, and Procedural. A literature search was conducted to describe the prevalence of disparities for eligibility criteria for African Americans/Black (AA/B), Hispanic/Latino (H/L), American Indian/Alaska Native (AI/AN) and Native Hawaiian/Pacific Islander (NH/PI) populations. The trials had a median of 15 criteria. The most frequent criterion were age cutoffs (87% of trials), specified neurologic (65%), and psychiatric disorders (61%). Underrepresented groups could be disproportionately excluded by 16 eligibility categories; 42% of trials specified English-speakers only in their criteria. Most trials (82%) contain poorly operationalized criteria (i.e., criteria not well defined that can have multiple interpretations/means of implementation) and criteria that may reduce racial/ethnic enrollment diversity.

Associations Between Ultra-Processed Food Consumption and Adverse Brain Health Outcomes

BACKGROUND AND OBJECTIVES

Ultra-processed foods (UPFs) are linked to cardiometabolic diseases and neurologic outcomes, such as cognitive decline and stroke. However, it is unclear whether food processing confers neurologic risk independent of dietary pattern information. We aimed to (1) investigate associations between UPFs and incident cognitive impairment and stroke and (2) compare these associations with other commonly recommended dietary patterns in the REasons for Geographic and Racial Differences in Stroke study. This prospective, observational cohort study enrolled Black and White adults in the United States from 2003 to 2007.

METHODS

The NOVA system was used to categorize items from a baseline food frequency questionnaire according to the level of processing. Participants with incomplete or implausible self-reported dietary data were excluded. Consumption for each category (grams) was normalized to total grams consumed. Scores quantifying adherence to a Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet were also calculated. Incident cognitive impairment was defined using performance relative to a normative sample on memory and fluency assessments. Incident stroke was identified through adjudicated review of medical records.

RESULTS

The cognitive impairment cohort (n = 14,175) included participants without evidence of impairment at baseline who underwent follow-up testing. The stroke cohort (n = 20,243) included participants without a history of stroke. In multivariable Cox proportional hazards models, a 10% increase in relative intake of UPFs was associated with higher risk of cognitive impairment (hazard ratio [HR] = 1.16, 95% CI 1.09-1.24, p = 1.01 × 10-5) and intake of unprocessed or minimally processed foods with lower risk of cognitive impairment (HR = 0.88, 95% CI 0.83-0.94, p = 1.83 × 10-4). Greater intake of UPFs (HR = 1.08, 95% CI 1.02-1.14, p = 1.12 × 10-2) and unprocessed or minimally processed foods (HR = 0.91, 95% CI 0.86-0.95, p = 2.13 × 10-4) were also associated with risk of stroke in multivariable Cox models. The effect of UPFs on stroke risk was greater among Black than White participants (UPF-by-race interaction HR = 1.15, 95% CI 1.03-1.29, p = 1.50 × 10-2). Associations between UPFs and both cognitive impairment and stroke were independent of adherence to the Mediterranean, DASH, and MIND diets.

DISCUSSION

Food processing may be important to brain health in older adults independent of known risk factors and adherence to recommended dietary patterns.

Development and validation of the Michigan Chronic Disease Simulation Model (MICROSIM)

Strategies to prevent or delay Alzheimer's disease and related dementias (AD/ADRD) are urgently needed, and blood pressure (BP) management is a promising strategy. Yet the effects of different BP control strategies across the life course on AD/ADRD are unknown. Randomized trials may be infeasible due to prolonged follow-up and large sample sizes. Simulation analysis is a practical approach to estimating these effects using the best available existing data. However, existing simulation frameworks cannot estimate the effects of BP control on both dementia and cardiovascular disease. This manuscript describes the design principles, implementation details, and population-level validation of a novel population-health microsimulation framework, the MIchigan ChROnic Disease SIMulation (MICROSIM), for The Effect of Lower Blood Pressure over the Life Course on Late-life Cognition in Blacks, Hispanics, and Whites (BP-COG) study of the effect of BP levels over the life course on dementia and cardiovascular disease. MICROSIM is an agent-based Monte Carlo simulation designed using computer programming best practices. MICROSIM estimates annual vascular risk factor levels and transition probabilities in all-cause dementia, stroke, myocardial infarction, and mortality in a nationally representative sample of US adults 18+ using the National Health and Nutrition Examination Survey (NHANES). MICROSIM models changes in risk factors over time, cognition and dementia using changes from a pooled dataset of individual participant data from 6 US prospective cardiovascular cohort studies. Cardiovascular risks were estimated using a widely used risk model and BP treatment effects were derived from meta-analyses of randomized trials. MICROSIM is an extensible, open-source framework designed to estimate the population-level impact of different BP management strategies and reproduces US population-level estimates of BP and other vascular risk factors levels, their change over time, and incident all-cause dementia, stroke, myocardial infarction, and mortality.

Racial Disparities in Blood Pressure at Time of Acute Ischemic Stroke Presentation: A Population Study

BACKGROUND

Hypertension is a stroke risk factor with known disparities in prevalence and management between Black and White patients. We sought to identify if racial differences in presenting blood pressure (BP) during acute ischemic stroke exist.

METHODS AND RESULTS

Adults with acute ischemic stroke presenting to an emergency department within 24 hours of last known normal during study epochs 2005, 2010, and 2015 within the Greater Cincinnati/Northern Kentucky Stroke Study were included. Demographics, histories, arrival BP, National Institutes of Health Stroke Scale score, and time from last known normal were collected. Multivariable linear regression was used to determine differences in mean BP between Black and White patients, adjusting for age, sex, National Institutes of Health Stroke Scale score, history of hypertension, hyperlipidemia, smoking, stroke, body mass index, and study epoch. Of 4048 patients, 853 Black and 3195 White patients were included. In adjusted analysis, Black patients had higher presenting systolic BP (161 mm Hg [95% CI, 159-164] versus 158 mm Hg [95% CI, 157-159], P<0.01), diastolic BP (86 mm Hg [95% CI, 85-88] versus 83 mm Hg [95% CI, 82-84], P<0.01), and mean arterial pressure (111 mm Hg [95% CI, 110-113] versus 108 mm Hg [95% CI, 107-109], P<0.01) compared with White patients. In adjusted subanalysis of patients <4.5 hours from last known normal, diastolic BP (88 mm Hg [95% CI, 86-90] versus 83 mm Hg [95% CI, 82-84], P<0.01) and mean arterial pressure (112 mm Hg [95% CI, 110-114] versus 108 mm Hg [95% CI, 107-109], P<0.01) were also higher in Black patients.

CONCLUSIONS

This population-based study suggests differences in presenting BP between Black and White patients during acute ischemic stroke. Further study is needed to determine whether these differences influence clinical decision-making, outcome, or clinical trial eligibility.

Sex-Associated Metabolites and Incident Stroke, Incident Coronary Heart Disease, Hypertension, and Chronic Kidney Disease in the REGARDS Cohort

BACKGROUND

Sex disparities exist in cardiometabolic diseases. Metabolomic profiling offers insight into disease mechanisms, as the metabolome is influenced by environmental and genetic factors. We identified metabolites associated with sex and determined if sex-associated metabolites are associated with incident stoke, incident coronary heart disease, prevalent hypertension, and prevalent chronic kidney disease.

METHODS AND RESULTS

Targeted metabolomics was conducted for 357 metabolites in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) case-cohort substudy for incident stroke. Weighted logistic regression models were used to identify metabolites associated with sex in REGARDS. Sex-associated metabolites were replicated in the HyperGEN (Hypertension Genetic Epidemiology Network) and using the literature. Weighted Cox proportional hazard models were used to evaluate associations between metabolites and incident stroke. Cox proportional hazard models were used to evaluate associations between metabolites and incident coronary heart disease. Weighted logistic regression models were used to evaluate associations between metabolites and hypertension and chronic kidney disease. Fifty-one replicated metabolites were associated with sex. Higher levels of 6 phosphatidylethanolamines were associated with incident stroke. No metabolites were associated with incident coronary heart disease. Higher levels of uric acid and leucine and lower levels of a lysophosphatidylcholine were associated with hypertension. Higher levels of indole-3-lactic acid, 7 phosphatidylethanolamines, and uric acid, and lower levels of betaine and bilirubin were associated with chronic kidney disease.

CONCLUSIONS

These findings suggest that the sexual dimorphism of the metabolome may contribute to sex differences in stroke, hypertension, and chronic kidney disease.

Trends in Demographic and Geographic Disparities in Stroke Mortality Among Older Adults in the United States

BACKGROUND

Stroke is a leading cause of morbidity and mortality in the United States among older adults. However, the impact of demographic and geographic risk factors remains ambiguous. A clear understanding of these associations and updated trends in stroke mortality can influence health policies and interventions.

METHODS

This study characterizes stroke mortality among older adults (age ≥55) in the US from January 1999 to December 2020, sourcing data from the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research. Segmented regression was used to analyze trends in crude mortality rate and age-adjusted mortality rate (AAMR) per 100,000 individuals stratified by stroke subcategory, sex, ethnicity, urbanization, and state.

RESULTS

A total of 3,691,305 stroke deaths occurred in older adults in the US between 1999 and 2020 (AAMR = 233.3), with an overall decrease in AAMR during these years. The highest mortality rates were seen in nonspecified stroke (AAMR = 173.5), those 85 or older (crude mortality rate1276.7), men (AAMR = 239.2), non-Hispanic African American adults (AAMR = 319.0), and noncore populations (AAMR = 276.1). Stroke mortality decreased in all states from 1999 to 2019 with the greatest and least decreases seen in California (-61.9%) and Mississippi (-35.0%), respectively. The coronavirus pandemic pandemic saw increased stroke deaths in most groups.

CONCLUSIONS

While there's a decline in stroke-related deaths among US older adults, outcome disparities remain across demographic and geographic sectors. The surge in stroke deaths during coronavirus pandemic reaffirms the need for policies that address these disparities.

Associations Between Stroke Type, Ischemic Stroke Subtypes, and Post-Stroke Cognitive Trajectories

Background

It is unclear how post-stroke cognitive trajectories differ by stroke type and ischemic stroke subtype. We studied associations between stroke types (ischemic, hemorrhagic), ischemic stroke subtypes (cardioembolic, large artery atherosclerotic, lacunar/small vessel, cryptogenic/other determined etiology), and post-stroke cognitive decline.

Methods

This pooled cohort analysis from four US cohort studies (1971-2019) identified 1,143 dementia-free individuals with acute stroke during follow-up: 1,061 (92.8%) ischemic, 82 (7.2%) hemorrhagic, 49.9% female, 30.8% Black. Median age at stroke was 74.1 (IQR, 68.6, 79.3) years. Outcomes were change in global cognition (primary) and changes in executive function and memory (secondary). Outcomes were standardized as T-scores (mean [SD], 50 [10]); a 1-point difference represents a 0.1-SD difference in cognition. Median follow-up for the primary outcome was 6.0 (IQR, 3.2, 9.2) years. Linear mixed-effects models estimated changes in cognition after stroke.

Results

On average, the initial post-stroke global cognition score was 50.78 points (95% CI, 49.52, 52.03) in ischemic stroke survivors and did not differ in hemorrhagic stroke survivors (difference, -0.17 points [95% CI, -1.64, 1.30]; P=0.82) after adjusting for demographics and pre-stroke cognition. On average, ischemic stroke survivors showed declines in global cognition, executive function, and memory. Post-stroke declines in global cognition, executive function, and memory did not differ between hemorrhagic and ischemic stroke survivors. 955 ischemic strokes had subtypes: 200 (20.9%) cardioembolic, 77 (8.1%) large artery atherosclerotic, 207 (21.7%) lacunar/small vessel, 471 (49.3%) cryptogenic/other determined etiology. On average, small vessel stroke survivors showed declines in global cognition and memory, but not executive function. Initial post-stroke cognitive scores and cognitive declines did not differ between small vessel survivors and survivors of other ischemic stroke subtypes. Post-stroke vascular risk factor levels did not attenuate associations.

Conclusion

Stroke survivors had cognitive decline in multiple domains. Declines did not differ by stroke type or ischemic stroke subtype.

Omega-3 Fatty Acids and Risk of Ischemic Stroke in REGARDS

We examined associations between lipidomic profiles and incident ischemic stroke in the REasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. Plasma lipids (n = 195) were measured from baseline blood samples, and lipids were consolidated into underlying factors using exploratory factor analysis. Cox proportional hazards models were used to test associations between lipid factors and incident stroke, linear regressions to determine associations between dietary intake and lipid factors, and the inverse odds ratio weighting (IORW) approach to test mediation. The study followed participants over a median (IQR) of 7 (3.4-11) years, and the case-cohort substudy included 1075 incident ischemic stroke and 968 non-stroke participants. One lipid factor, enriched for docosahexaenoic acid (DHA, an omega-3 fatty acid), was inversely associated with stroke risk in a base model (HR = 0.84; 95%CI 0.79-0.90; P = 8.33 × 10-8) and fully adjusted model (HR = 0.88; 95%CI 0.83-0.94; P = 2.79 × 10-4). This factor was associated with a healthy diet pattern (β = 0.21; 95%CI 0.12-0.30; P = 2.06 × 10-6), specifically with fish intake (β = 1.96; 95%CI 0.95-2.96; P = 1.36 × 10-4). DHA was a mediator between fish intake and incident ischemic stroke (30% P = 5.78 × 10-3). Taken together, DHA-containing plasma lipids were inversely associated with incident ischemic stroke and mediated the relationship between fish intake and stroke risk.

Differences in Receipt of Neurologist Evaluation During Hospitalization for Ischemic Stroke by Race, Sex, Age, and Region: The REGARDS Study

BACKGROUND AND OBJECTIVES

Improving access to health care providers with clinical expertise in stroke care may influence the use of recommended strategies for reducing disparities in quality of care. Few studies have examined differences in the receipt of evaluation by neurologists during the hospital stay. We examined the proportion of individuals hospitalized for acute ischemic stroke who received evaluation by a neurologist during the hospital stay and characterized differences in receipt of neurologist evaluation by race (Black vs White), sex, age, and study region (Stroke Belt residence vs other) among those experiencing a stroke who were participating in a national cohort study.

METHODS

This cross-sectional study was conducted using medical record data abstracted from 1,042 participants enrolled in the national Reasons for Geographic and Racial Differences in Stroke cohort study (2003-2007) who experienced an adjudicated ischemic stroke between 2003 and 2016. Participants with a history of stroke before baseline, in-hospital death, hospice discharge following their stroke, or incomplete records were excluded resulting in 839 cases. Differences were assessed using modified Poisson regression adjusting for participant-level and hospital-level factors.

RESULTS

Of the 839 incident strokes, 722 (86%) received evaluation by a neurologist during the hospital stay. There were no significant differences by age, race, or sex, yet Stroke Belt residents and those receiving care in rural hospitals were significantly less likely to receive neurologist evaluation compared with non-Stroke Belt residents (relative risk [RR] 0.95; 95% CI 0.90-1.01) and participants receiving care in urban hospitals (RR 0.74; 95% CI 0.63-0.86). Participants with a greater level of poststroke functional impairment (modified Rankin scale) and those with a greater number of risk factors were more likely to receive neurologist evaluation compared with those with lower levels of poststroke functional impairment (RR 1.04; 95% CI 1.01-1.06) and fewer risk factors (RR 1.02; 95% CI 1.00-1.04).

DISCUSSION

While differences in access to neurologists during the hospital stay were partially explained by patient need in our study, there were also significant differences in access by region and urban-rural hospital status. Ensuring access to neurologists during the hospital stay in such settings may require policy-level and/or system-level changes.

Sherman Lecture: Are We Aiming at the Correct Targets to Reduce Disparities in Stroke Mortality? Celebration, Reflection, and Redirection

Although deaths from stroke have been reduced by 75% in the past 54 years, there has been virtually no reduction in the relative magnitude of Black-to-White disparity in stroke deaths, or the heavier burden of stroke deaths in the Stroke Belt region of the United States. Furthermore, although the rural-urban disparity has decreased in the past decade, this reduction is largely attributable to an increased stroke mortality in the urban areas, rather than reduced stroke mortality in rural areas. We need to focus our search for interventions to reduce disparities on those that benefit the disadvantaged populations, and support this review using relatively recently developed statistical approaches to estimate the magnitude of the potential reduction in the disparities.

Addressing disparities in the global epidemiology of stroke

Stroke is the second leading cause of death and the third leading cause of disability worldwide. Though the burden of stroke worldwide seems to have declined in the past three decades, much of this effect reflects decreases in high-income countries (HICs). By contrast, the burden of stroke has grown rapidly in low-income and middle-income countries (LMICs), where epidemiological, socioeconomic and demographic shifts have increased the incidence of stroke and other non-communicable diseases. Furthermore, even in HICs, disparities in stroke epidemiology exist along racial, ethnic, socioeconomic and geographical lines. In this Review, we highlight the under-acknowledged disparities in the burden of stroke. We emphasize the shifting global landscape of stroke risk factors, critical gaps in stroke service delivery, and the need for a more granular analysis of the burden of stroke within and between LMICs and HICs to guide context-appropriate capacity-building. Finally, we review strategies for addressing key inequalities in stroke epidemiology, including improvements in epidemiological surveillance and context-specific research efforts in under-resourced regions, development of the global workforce of stroke care providers, expansion of access to preventive and treatment services through mobile and telehealth platforms, and scaling up of evidence-based strategies and policies that target local, national, regional and global stroke disparities.

Sleep duration and all-cause mortality among stroke survivors

BACKGROUND

Post stroke sleep duration could increase the risk of death. This study tested the hypothesis that inadequate sleep duration is associated with increased mortality among stroke survivors.

METHODS

The REasons for Geographic And Racial Differences in Stroke (REGARDS), a national population-based longitudinal study, was the data source. Sleep duration was ascertained between 2013 and 2016 among stroke survivors who were subsequently followed up until death or censored on December 31, 2022. Sleep duration was estimated as the difference between wake-up time and bedtime to which was subtracted the time spent in bed without sleep. Cox proportional hazards regression models were employed to investigate the association between sleep duration and all-cause mortality adjusting for demographic factors, socioeconomic factors, behavioral factors, and co-morbidities.

RESULTS

A total of 468 non-Hispanic Black and White stroke survivors were included in this analysis. The mean age was 76.3 years, 52.6% were females and 56.0% were non-Hispanic White individuals. The distribution of short (≤6 h), adequate (7.0-8.9 h), and long sleep (≥9 h) was 30.3%, 44.7%, and 25%, respectively. Over a mean follow-up of 5.0 years, 190 (40.6%) deaths occurred. Compared to stroke survivors with adequate sleep (7.0-8.9 h), stroke survivors with long sleep (≥9 h) were at increased risk of all-cause mortality (HR=1.46, 95% CI=1.01, 2.12). However, short sleep (≤6 h) was not significantly associated with an increased risk of all-cause mortality (HR=1.31, 95% CI=0.90, 1.91). Subgroup analyses indicated higher risk in the age <75 years, females, non-Hispanic Black individuals, and those living in the Stroke Belt region, but those differences were not statistically significant.

CONCLUSION

In this study of stroke survivors, 9 hours or more of sleep per day was associated with an increased risk of all-cause mortality. This finding suggests that excessive sleep duration may be a warning sign of poor life expectancy in stroke survivors.

Racial and Ethnic Disparities in Neurological Care in the United States

The burden of neurological disease is increasing globally. In the United States, this burden is disproportionally greater for Black and Latino communities who have limited access to neurological care. Health services researchers have attempted to identify racial and ethnic disparities in neurological care and possible solutions. This article reviews the most current literature on racial and ethnic disparities in commonly encountered neurological conditions, including Stroke, Alzheimer's Disease, Multiple Sclerosis, Epilepsy, Parkinson's Disease, and Migraine. Disparities exist in disease incidence, diagnosis, access to care, treatment, outcomes, and representation in epidemiologic studies and clinical trials. Many of the disparities observed in neurological care in the United States are a consequence of longstanding racist and discriminatory policies and legislation that increase risk factors for the development of neurological disease or lead to disparities in accessing quality neurological care. Therefore, additional efforts on the legislative, community health, and healthcare system levels are necessary to prevent the onset of neurological disease and achieve equity in neurological care.

Disparities in Race and Ethnicity Reporting and Representation for Clinical Trials in Stroke: 2010 to 2020

BACKGROUND

Racial and ethnic minority groups are at a higher stroke risk and have poor poststroke outcomes. The aim of this study was to assess the frequency of race reporting and proportions of race and ethnicity representation in stroke-related clinical trials.

METHODS AND RESULTS

This is a descriptive study of stroke-related clinical trials completed between January 1, 2010 and December 31, 2020, and registered on ClinicalTrials.gov. Trials conducted in the United States, related to stroke and enrolling participants ≥18 years, were considered eligible. Trials were reviewed for availability of published results, data on race and ethnicity distribution, and trial characteristics. Overall, 60.1% of published trials reported race or ethnicity of participants, with a 2.6-fold increase in reporting between 2010 and 2020. White patients represented 65.0% of the participants, followed by 24.8% Black, 2.4% Asian or Pacific Islander, and <1% Native American and multiracial participants; 9.0% were of Hispanic ethnicity. These trends remained consistent throughout the study period, except in 2018, when a higher proportion of Black participants (53.1%) was enrolled compared with White participants (35.8%). Trials with the National Institutes of Health/federal funding had higher enrollment of Black (28.1%) and Hispanic (13.8%) participants compared with other funding sources. Behavioral intervention trials had the most diverse enrollment with equal enrollment of Black and White participants (41.1%) and 14.5% Hispanic participants.

CONCLUSIONS

Despite the increase in race and ethnicity reporting between 2010 and 2020, the representation of racial and ethnic minority groups remains low in stroke trials. Funding initiatives may influence diversity efforts in trial enrollment.

Comparative Discrimination of Life's Simple 7 and Life's Essential 8 to Stratify Cardiovascular Risk: Is the Added Complexity Worth It?

BACKGROUND

Life's Simple 7 (LS7) is an easily calculated and interpreted metric of cardiovascular health based on 7 domains: smoking, diet, physical activity, body mass index, blood pressure, cholesterol, and fasting glucose. The Life's Essential 8 (LE8) metric was subsequently introduced, adding sleep metrics and revisions of the previous 7 domains. Although calculating LE8 requires additional information, we hypothesized that it would be a more reliable index of cardiovascular health.

METHODS

Both the LS7 and LE8 metrics yield scores with higher values indicating lower risk. These were calculated among 11 609 Black and White participants free of baseline cardiovascular disease (CVD) in the Reasons for Geographic and Racial Differences in Stroke study, enrolled in 2003 to 2007, and followed for a median of 13 years. Differences in 10-year risk of incident CVD (coronary heart disease or stroke) were calculated as a function LS7, and LE8 scores were calculated using Kaplan-Meier and proportional hazards analyses. Differences in incident CVD discrimination were quantified by difference in the c-statistic.

RESULTS

For both LS7 and LE8, the 10-year risk was approximately 5% for participants around the 99th percentile of scores, and a 4× higher 20% risk for participants around the first percentile. Comparing LS7 to LE8, 10-year risk was nearly identical for individuals at the same relative position in score distribution. For example, the "cluster" of 2013 participants with an LS7 score of 7 was at the 35.8th percentile in distribution of LS7 scores, and had an estimated 10-year CVD risk of 8.4% (95% CI, 7.2%-9.8%). In a similar location in the LE8 distribution, the 1457 participants with an LE8 score of 60±2.5 at the 39.4th percentile of LE8 scores had a 10-year risk of CVD of 8.5% (95% CI, 7.1%-10.1%), similar to the cluster defined by LS7. The age-race-sex adjusted c-statistic of the LS7 model was 0.691 (95% CI, 0.667-0.705), and 0.695 for LE8 (95% CI, 0.681-0.709) (P for difference, 0.12).

CONCLUSIONS

Both LS7 and LE8 were associated with incident CVD, with discrimination of the 2 indices practically indistinguishable. As a simpler metric, LS7 may be favored for use by the general population and clinicians.

Long-term exposure to air pollution and risk of stroke by ecoregions: The REGARDS study

Several cohort studies have found associations between long-term exposure to air pollution and stroke risk. However, it is unclear whether the surrounding ecology may modify these associations. This study evaluates associations of air pollution with stroke risk by ecoregions, which are areas of similar type, quality, and quantity of environmental resources in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. We assessed the incidence of stroke in 26,792 participants (45+ yrs) from the REGARDS study, a prospective cohort recruited across the contiguous United States. One-yr and 3-yr means of PM2.5, PM10, O3, NO2, SO2, and CO were estimated at baseline using data from the Center for Air, Climate, & Energy Solution, and assigned to participants at the census block group level. Incident stroke was ascertained through September 30, 2020. Relations of air pollutants with the risk of incident stroke were estimated using Cox proportional hazards models, adjusting for relevant demographics, behavioral risk factors, and neighborhood urbanicity. Models were stratified by EPA designated ecoregions. A 5.4 μg/m3 (interquartile range) increase in 1-yr PM10 was associated with a hazard ratio (95 %CI) for incident stroke of 1.07 (1.003, 1.15) in the overall study population. We did not find evidence of positive associations for PM2.5, O3, NO2, SO2, and CO in the fully adjusted models. In our ecoregion-specific analysis, associations of PM2.5 with stroke were stronger in the Great Plains ecoregion (HR = 1.44) than other ecoregions, while associations for PM10 were strongest in the Eastern Temperate Forests region (HR = 1.15). The associations between long-term exposure to air pollution and risk of stroke varied by ecoregion. Our results suggests that the type, quality, and quantity of the surrounding ecology can modify the effects of air pollution on risk of stroke.

Carotid Intima-Media Thickness and Improved Stroke Risk Assessment in Hypertensive Black Adults

BACKGROUND

We aim to determine the added value of carotid intima-media thickness (cIMT) in stroke risk assessment for hypertensive Black adults.

METHODS

We examined 1,647 participants with hypertension without a history of cardiovascular (CV) disease, from the Jackson Heart Study. Cox regression analysis estimated hazard ratios (HRs) for incident stroke per standard deviation increase in cIMT and quartiles while adjusting for baseline variables. We then evaluated the predictive capacity of cIMT when added to the pool cohort equations (PCEs).

RESULTS

The mean age at baseline was 57 ± 10 years. Each standard deviation increase in cIMT (0.17 mm) was associated with approximately 30% higher risk of stroke (HR 1.27, 95% confidence interval: 1.08-1.49). Notably, cIMT proved valuable in identifying residual stroke risk among participants with well-controlled blood pressure, showing up to a 56% increase in the odds of stroke for each 0.17 mm increase in cIMT among those with systolic blood pressure <120 mm Hg. Additionally, the addition of cIMT to the PCE resulted in the reclassification of 58% of low to borderline risk participants with stroke to a higher-risk category and 28% without stroke to a lower-risk category, leading to a significant net reclassification improvement of 0.22 (0.10-0.30).

CONCLUSIONS

In this community-based cohort of middle-aged Black adults with hypertension and no history of CV disease at baseline, cIMT is significantly associated with incident stroke and enhances stroke risk stratification.

Atherosclerotic cardiovascular disease events among adults with high predicted risk without established risk factors

Objective

Age is the strongest contributor to 10-year predicted atherosclerotic cardiovascular disease (ASCVD) risk. Some older adults have a predicted ASCVD risk ≥7.5 %, without established risk factors. We sought to compare ASCVD incidence among adults with predicted ASCVD risk ≥7.5 %, with and without established ASCVD risk factors, to adults with predicted risk <7.5 %.

Methods

We analyzed data from REasons for Geographic and Racial Differences in Stroke study participants, 45-79 years old, without ASCVD or diabetes, not taking statins and with low-density lipoprotein cholesterol 70-189 mg/dL. Participants were categorized into 3 groups based on their 10-year predicted ASCVD risk and presence of established risk factors: <7.5 %, ≥7.5 % with established risk factors and ≥7.5 % without established risk factors. Established risk factors included smoking, systolic blood pressure ≥130 mmHg or antihypertensive medication use, total cholesterol ≥200 mg/dL, or high-density lipoprotein cholesterol <50 mg/dL for women (<40 mg/dL for men). Participants were followed for ASCVD events.

Results

Among 11,115 participants, 911 incident ASCVD events occurred over a median of 11.1 years. ASCVD incidence rates were 3.6, 12.8, and 9.8 per 1,000 person-years for participants with predicted risk <7.5 %, predicted risk ≥7.5 % with established risk factors and predicted risk ≥7.5 % without established risk factors, respectively. Compared to adults with predicted risk <7.5 %, hazard ratios for incident ASCVD in participants with risk ≥7.5 % with and without established risk factors were 3.58 (95 %CI 3.03 - 4.21) and 2.72 (95 %CI 1.91-3.88), respectively.

Conclusions

Adults with a 10-year predicted ASCVD risk ≥7.5 % but without established risk factors had a high ASCVD incidence.

Racial disparities in stroke incidence in the Women's Health Initiative: Exploring biological, behavioral, psychosocial, and social risk factors

Background

- Disparities in incident stroke risk among women by race and ethnicity persist. Few studies report the distribution and association of stroke risk factors by age group among a diverse sample of women.

Methods

- Data from the Women's Health Initiative (WHI) Observational Study collected between 1993 and 2010 were used to calculate cumulative stroke incidence and incidence rates among non-Hispanic African American (NHAA), non-Hispanic white (NHW), and Hispanic white or African American (HWAA) women by age group in participants aged ≥50 years at baseline (N = 77,247). Hazard ratios (HRs) and 95% CIs for biological, behavioral, psychosocial, and socioeconomic factors overall and by race or ethnicity were estimated using sequential Cox proportional hazard regression models.

Results

- Average follow-up time was 11.52 (SD, 3.48) years. The incident stroke rate was higher among NHAA (306 per 100,000 person-years) compared to NHW (279/100,000py) and HWAA women (147/100,000py) overall and in each age group. The disparity was largest at ages >75 years. The association between stroke risk factors (e.g., smoking, BMI, physical activity) and incident stroke varied across race and ethnicity groups. Higher social support was significantly associated with decreased stroke risk overall (HR:0.84, 95% CI, 0.76, 0.93); the degree of protection varied across race and ethnicity groups. Socioeconomic factors did not contribute additional stroke risk beyond risk conferred by traditional and psychosocial factors.

Conclusions

- The distribution and association of stroke risk factors differed between NHAA and NHW women. There is a clear need for stroke prevention strategies that address factors driving racial disparities in stroke risk.

Trends Over Time in Stroke Incidence by Race in the Greater Cincinnati Northern Kentucky Stroke Study

BACKGROUND AND OBJECTIVES

Understanding the current status of and temporal trends of stroke epidemiology by age, race, and stroke subtype is critical to evaluate past prevention efforts and to plan future interventions to eliminate existing inequities. We investigated trends in stroke incidence and case fatality over a 22-year time period.

METHODS

In this population-based stroke surveillance study, all cases of stroke in acute care hospitals within a 5-county population of southern Ohio/northern Kentucky in adults aged ≥20 years were ascertained during a full year every 5 years from 1993 to 2015. Temporal trends in stroke epidemiology were evaluated by age, race (Black or White), and subtype (ischemic stroke [IS], intracranial hemorrhage [ICH], or subarachnoid hemorrhage [SAH]). Stroke incidence rates per 100,000 individuals from 1993 to 2015 were calculated using US Census data and age-standardized, race-standardized, and sex-standardized as appropriate. Thirty-day case fatality rates were also reported.

RESULTS

Incidence rates for stroke of any type and IS decreased in the combined population and among White individuals (any type, per 100,000, 215 [95% CI 204-226] in 1993/4 to 170 [95% CI 161-179] in 2015, p = 0.015). Among Black individuals, incidence rates for stroke of any type decreased over the study period (per 100,000, 349 [95% CI 311-386] in 1993/4 to 311 [95% CI 282-340] in 2015, p = 0.015). Incidence of ICH was stable over time in the combined population and in race-specific subgroups, and SAH decreased in the combined groups and in White adults. Incidence rates among Black adults were higher than those of White adults in all time periods, and Black:White risk ratios were highest in adults in young and middle age groups. Case fatality rates were similar by race and by time period with the exception of SAH in which 30-day case fatality rates decreased in the combined population and White adults over time.

DISCUSSION

Stroke incidence is decreasing over time in both Black and White adults, an encouraging trend in the burden of cerebrovascular disease in the US population. Unfortunately, however, Black:White disparities have not decreased over a 22-year period, especially among younger and middle-aged adults, suggesting the need for more effective interventions to eliminate inequities by race.

A Segmented Regression Analysis of Household Income and Recurrent Falls Among Adults in a National Cohort Study

Falls can have life-altering consequences for older adults, including extended recovery periods and compromised independence. Higher household income may mitigate the risk of falls by providing financial resources for mobility tools, remediation of environmental hazards, and needed supports, or it may buffer the impact of an initial fall on subsequent risk through improved assistance and care. Household income has not had a consistently observed association with falls in older adults; however, a segmented association may exist such that associations are attenuated above a certain income threshold. In this study, we utilized segmented negative binomial regression analysis to examine the association between household income and recurrent falls among 2,302 participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study recruited between 2003 and 2007. Income-fall association segments separated by changes in slope were considered. Model results indicated a 2-segment association between household income and recurrent falls in the past year. In the range below the breakpoint, household income was negatively associated with the rate of recurrent falls across all age groups examined; in a higher income range (from $20,000-$49,999 to ≥$150,000), the association was attenuated (weaker negative trend) or reversed (positive trend). These findings point to potential benefits of ensuring that incomes for lower-income adults exceed the threshold needed to confer a reduced risk of recurrent falls.

Ethnicity-specific blood pressure thresholds based on cardiovascular and renal complications: a prospective study in the UK Biobank

BACKGROUND

The appropriateness of hypertension thresholds for triggering action to prevent cardiovascular and renal complications among non-White populations in the UK is subject to question. Our objective was to establish ethnicity-specific systolic blood pressure (SBP) cutoffs for ethnic minority populations and assess the efficacy of these ethnicity-specific cutoffs in predicting adverse outcomes.

METHODS

We analyzed data from UK Biobank, which included 444,418 participants from White, South Asian, Black Caribbean, and Black African populations with no history of cardiorenal complications. We fitted Poisson regression models with continuous SBP and ethnic groups, using Whites as the referent category, for the composite outcome of atherosclerotic cardiovascular disease, heart failure, and chronic kidney disease. We determined ethnicity-specific thresholds equivalent to the risks observed in Whites at SBP levels of 120, 130, and 140 mm Hg. We adjusted models for clinical characteristics, sociodemographic factors, and behavioral factors. The performance of ethnicity-specific thresholds for predicting adverse outcomes and associated population-attributable fraction (PAF) was assessed in ethnic minority groups.

RESULTS

After a median follow-up of 12.5 years (interquartile range, 11.7-13.2), 32,662 (7.4%) participants had incident composite outcomes. At any given SBP, the predicted incidence rate of the composite outcome was the highest for South Asians, followed by White, Black Caribbean, and Black African. For an equivalent risk of outcomes observed in the White population at an SBP level of 140 mm Hg, the SBP threshold was lower for South Asians (123 mm Hg) and higher for Black Caribbean (156 mm Hg) and Black African (165 mm Hg). Furthermore, hypertension defined by ethnicity-specific thresholds was a stronger predictor and resulted in a larger PAF for composite outcomes in South Asians (21.5% [95% CI, 2.4,36.9] vs. 11.3% [95% CI, 2.6,19.1]) and Black Africans (7.1% [95% CI, 0.2,14.0] vs. 5.7 [95% CI, -16.2,23.5]) compared to hypertension defined by guideline-recommended thresholds.

CONCLUSIONS

Guideline-recommended blood pressure thresholds may overestimate risks for the Black population and underestimate risks for South Asians. Using ethnicity-specific SBP thresholds may improve risk estimation and optimize hypertension management toward the goal of eliminating ethnic disparities in cardiorenal complications.

Sex and Race Differences in Obesity-Related Genetic Susceptibility and Risk of Cardiometabolic Disease in Older US Adults

Importance

The fat mass and obesity-associated gene (FTO) is associated with obesity phenotypes, but the association is inconsistent across populations. Within-population differences may explain some of the variability observed.

Objective

To investigate sex differences in the association between FTO single-nucleotide variants (SNVs) and obesity traits among self-identified non-Hispanic Black and non-Hispanic White US adults, to examine whether the SNVs were associated with cardiometabolic diseases, and to evaluate whether obesity mediated the association between FTO SNVs and cardiometabolic diseases.

Design, Setting, and Participants

This cross-sectional study used data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a US population-based cohort study with available genetic data (assayed in 2018) and phenotypic data at baseline (enrolled 2003-2007). Participants were aged 45 to 98 years at baseline. Data were analyzed from October 2021 to October 2022.

Exposures

Eleven SNVs in the FTO gene present among both Black and White participants.

Main Outcomes and Measures

Objectively measured obesity indicators (body mass index and waist-to-height ratio), objectively measured and/or self-reported cardiometabolic diseases (hypertension, stroke history, heart disease, and diabetes), and self-reported social-economic and psychosocial status.

Results

A total of 10 447 participants (mean [SD] age, 64.4 [9.7] years; 5276 [55.8%] women; 8743 [83.7%] Black and 1704 [16.3%] White) were included. In the White group, 11 FTO SNVs were significantly associated with obesity, hypertension, and diabetes using linear models (eg, body mass index: β = 0.536; 95% CI, 0.197-0.875), but none of the FTO SNVs were associated with obesity traits in the Black group. White males had a higher risk of obesity while White females had a higher risk of hypertension and diabetes. However, 1 FTO SNV (rs1121980) was associated with a direct increase in the risk of heart disease in Black participants not mediated by obesity (c' = 0.145 [SE, 0.0517]; P = .01).

Conclusions and Relevance

In this cross-sectional study of obesity phenotypes and their association with cardiometabolic diseases, the tested FTO SNVs reflected sex differences in White participants. Different patterns of associations were observed among self-identified Black participants. Therefore, these results could inform future work discovering risk alleles or risk scores unique to Black individuals or further investigating genetic risk in all US residents.

Clinical and demographic predictors of unilateral spatial neglect recovery after prism therapy among stroke survivors in the sub-acute phase of recovery

BACKGROUND AND AIMS: Unilateral Spatial Neglect (USN) affects the rehabilitation process and leads to poor outcomes after stroke. Factors that influence USN recovery following prism adaptation therapy have not been investigated. This study investigated predictors of USN recovery after prism therapy at the sub-acute phase of recovery. METHODS: This study was a randomized controlled trial. USN was assessed with the Behavioural Inattention Test and Catherine Bergego scale. Seventy-four patients with USN were divided into control and intervention group (prism). The prism group used 20 dioptre prism lenses for repeated aiming for 12 sessions while the control group used neutral lenses for aiming training. Regression analysis was conducted to establish clinical and sociodemographic factors that influence USN recovery. RESULTS: Gender, age, years of education, race, employment status, handedness, type of stroke, time since stroke and site of stroke (p > 0.005) showed no significant influence on USN recovery following PA treatment. Higher Cognitive function (OR  = 1.52, CI = 1.08-2.14, p =  0.016) and group allocationng (being in the prism group) (OR = 63.10, CI =  9.70-410.59, P < 0.001) were found to significantly influence USN recovery following PA treatment session. CONCLUSIONS: A significant modulating effect on general cognitive ability was found in this study. This suggests that prism adaptation therapy's effect on neural activity and spatial neglect depends on the cognitive function of stroke survivors.Trial registration: Pan African Clinical Trial Registry identifier: PACTR201903732473573.

History of obstructive sleep apnea associated with incident cognitive impairment in white but not black individuals in a US national cohort study

BACKGROUND

We sought to determine if risk for obstructive sleep apnea (OSA), a history of OSA, and/or treatment of OSA has a different association with incident cognitive impairment or cognitive decline in Black individuals and White individuals.

METHODS

To determine whether the risk for OSA, a history of OSA, and/or treatment of OSA has a different association with incident cognitive impairment or cognitive decline in Black individuals and White individuals; data from the REasons for Geographic and Racial Differences in Stroke (REGARDS) was used. Participants that completed the sleep questionnaire module, had baseline cognitive assessment, and at least one cognitive assessment during follow-up were included. Risk of OSA was determined based on Berlin Sleep Questionnaire. History of sleep apnea was determined based on structured interview questions. Optimally treated OSA was defined as treated sleep apnea as at least 4 h of continuous positive airway pressure use per night for ≥5 nights per week.

RESULTS

In 19,017 participants stratified by race, White participants with history of OSA were 1.62 times more likely to have incident cognitive impairment compared to White participants without history of OSA after adjusting for demographic characteristics, history, and lifestyle factors (OR = 1.62, 95% CI = 1.05-2.50, p-value = 0.03). This relationship was not seen in Black participants (OR = 0.92, 95% CI = 0.60-1.43, p-value = 0.72).

DISCUSSION

A previous diagnosis of OSA is associated with incident cognitive impairment in White Americans but not Black Americans. Further investigations are required to determine the mechanism for this difference.

Policy implementation strategies to address rural disparities in access to care for stroke patients

Context

Stroke systems of care (SSOC) promote access to stroke prevention, treatment, and rehabilitation and ensure patients receive evidence-based treatment. Stroke patients living in rural areas have disproportionately less access to emergency medical services (EMS). In the United States, rural counties have a 30% higher stroke mortality rate compared to urban counties. Many states have SSOC laws supported by evidence; however, there are knowledge gaps in how states implement these state laws to strengthen SSOC.

Objective

This study identifies strategies and potential challenges to implementing state policy interventions that require or encourage evidence-supported pre-hospital interventions for stroke pre-notification, triage and transport, and inter-facility transfer of patients to the most appropriate stroke facility.

Design

Researchers interviewed representatives engaged in implementing SSOC across six states. Informants (n = 34) included state public health agency staff and other public health and clinical practitioners.

Outcomes

This study examined implementation of pre-hospital SSOCs policies in terms of (1) development roles, processes, facilitators, and barriers; (2) implementation partners, challenges, and solutions; (3) EMS system structure, protocols, communication, and supervision; and (4) program improvement, outcomes, and sustainability.

Results

Challenges included unequal resource allocation and EMS and hospital services coverage, particularly in rural settings, lack of stroke registry usage, insufficient technologies, inconsistent use of standardized tools and protocols, collaboration gaps across SSOC, and lack of EMS stroke training. Strategies included addressing scarce resources, services, and facilities; disseminating, training on, and implementing standardized statewide SSOC protocols and tools; and utilizing SSOC quality and performance improvement systems and approaches.

Conclusions

This paper identifies several strategies that can be incorporated to enhance the implementation of evidence-based stroke policies to improve access to timely stroke care for all patient populations, particularly those experiencing disparities in rural communities.

Addressing racial differences in the management of atrial fibrillation: Focus on black patients

Atrial fibrillation (AF) is the most common sustained arrhythmia, affecting between 3 and 6 million people in the United States. It is associated with a reduced quality of life and increased risk of stroke, cognitive decline, heart failure and death. Black patients have a lower prevalence of AF than White patients but are more likely to suffer worse outcomes with the disease. It is important that stakeholders understand the disproportionate burden of disease and management gaps that exists among Black patients living with AF. Appropriate treatments, including aggressive risk factor control, early referral to cardiovascular specialists and improving healthcare access may bridge some of the gaps in management and improve outcomes.

Smoking Modifies the Association Between Radon Exposure and Incident Ischemic Stroke: The REGARDS Study

BACKGROUND

Exposure to radon has been linked to lung cancer and other lung diseases. Although biologically plausible, research of residential radon exposure in relation to stroke risk is scarce.

METHODS

Study participants were from the REGARDS (Reasons for Geographic and Racial Differences in Stroke) cohort (n=30 239), which consisted of male and female non-Hispanic Black and White adults aged 45 and older. After excluding participants with baseline stroke and transient ischemic attack, and missing information on exposure and outcome of interest, the final sample size was 26 950. The primary outcome was time to the first ischemic stroke through September 30, 2020. County-level radon measures from Lawrence Berkeley National Laboratory were linked to each participant based on their geocoded residential history. We used Cox proportional hazards regression models with a time-dependent exposure to estimate hazard ratios and 95% CIs for the association.

RESULTS

After controlling for potential confounding factors including demographic, lifestyle, clinical variables, and PM2.5, radon exposure was significantly associated with incident ischemic stroke among never-smokers (hazard ratio, 1.39 [95% CI, 1.01-1.90]) but not ever-smokers. The results were generally consistent in the sensitivity analysis when using radon measures from state/Environmental Protection Agency residential radon survey.

CONCLUSIONS

Findings from this study suggest that the association between residential radon exposure and incidence of ischemic stroke varies by smoking status and may be prominent in never-smokers. Further studies incorporating indoor-radon measures are needed to confirm these findings.

Black Americans have worse stroke outcome compared with non-Hispanic whites

INTRODUCTION

We studied racial differences in post-stroke outcomes using a prospective, population-based cohort of stroke survivors as part of the Brain Attack Surveillance in Corpus Christi (BASIC) project.

METHODS

Neurologic (NIHSS, range of 0-42, higher scores are worse), functional (ADLs/IADLs, range 1-4, higher scores are worse), and cognitive (3MSE, range 0-100, higher scores are better) outcomes were measured 90 days after stroke. Cox proportional hazards and negative binomial linear regression models were used to examine the associations between race and 90-day all-cause mortality and NIHSS, respectively, whereas linear regression was used for ADLs/IADLs and 3MSE scores. Covariates included demographics, initial NIHSS, comorbidities, prior stroke history, tPA treatment status, pre-stroke disability, and pre-stroke cognition. The mortality model was also adjusted for DNR status.

RESULTS

At 90 days post-stroke, Black American individuals (BAs) (n = 122) had a median (IQR) NIHSS of 2 (1,6) compared to NIHSS of 1 (0,3) in non-Hispanic White American individuals (NHWs) (n = 795). BAs had a median (IQR) ADL/IADL score of 2.41 (1.50, 3.39) compared to 2.00 (1.27, 2.95) in NHWs. BAs scored a median of 84 (75, 92) on the 3MSE compared to NHWs' score of 91.5 (83, 96). Death occurred in 23 (8%) of BAs and 268 (15%) of NHWs within 90 days among those who participated in baseline. After adjustment for covariates, functional outcomes at 90 days were worse in BAs compared to NHWs, with 15.8% (95% CI=5.2, 26.4) greater limitations in ADLs/IADLs and 43.9% (95% CI=12.0, 84.9) greater severity of stroke symptoms. Cognition at 90 days was 6.5% (95% CI=2.4, 10.6) lower in BAs compared to NHWs. BAs had a 35.4% lower (95% CI=-9.8, 61.9) hazard rate of mortality than NHWs.

CONCLUSIONS

In this prospective, population-based community sample, BAs had worse neurologic, functional and cognitive outcomes at 90 days compared to NHWs. Future research should investigate how social determinants of health including structural racism, neighborhood factors and access to preventive and recovery services influences these racial disparities.

Hypertensive Disorders of Pregnancy and Risk of Stroke in U.S. Black Women

BACKGROUND: Black women have a disproportionately higher burden of both preeclamptic pregnancy and stroke compared with White women, but virtually all existing evidence on this possible association has been generated from women of European ancestry. METHODS: In the Black Women’s Health Study, a prospective cohort of U.S. Black women who enrolled in 1995, 42,924 participants were parous and free of cardiovascular disease at baseline. Biennial questionnaires included questions on preeclampsia, gestational hypertension, and stroke. We sought the medical records for participants who reported a stroke, and we reviewed them blinded to reproductive history. Cox proportional-hazards models, with control for potential confounders, were used to estimate hazard ratios and 95% confidence intervals (CIs). RESULTS: Over a median of 22 years of follow-up, there were 1555 incident strokes, including 310 among 4938 women with a history of hypertensive disorders of pregnancy (HDOP). The multivariable hazard ratio for stroke for women with any HDOP compared with those who had never experienced HDOP was 1.66 (95% CI, 1.46 to 1.89). Comparable hazard ratios were 1.53 (95% CI, 1.29 to 1.82) for preeclampsia and 1.81 (95% CI, 1.53 to 2.13) for gestational hypertension only. Associations were similar among women under age 55 years and those aged 55 years and older. CONCLUSIONS: In this prospective study of Black women, a history of HDOP was associated with an estimated 66% increased long-term risk of stroke. This association may contribute to the disproportionately higher stroke incidence in Black women given the higher prevalence of HDOP in this population. (Funded by the U.S. National Institutes of Health.)

The predominant PAR4 variant in individuals of African ancestry worsens murine and human stroke outcomes

Protease-activated receptor 4 (PAR4) (gene F2RL3) harbors a functional dimorphism, rs773902 A/G (encoding Thr120/Ala120, respectively) and is associated with greater platelet aggregation. The A allele frequency is more common in Black individuals, and Black individuals have a higher incidence of ischemic stroke than White individuals. However, it is not known whether the A allele is responsible for worse stroke outcomes. To directly test the in vivo effect of this variant on stroke, we generated mice in which F2rl3 was replaced by F2RL3, thereby expressing human PAR4 (hPAR4) with either Thr120 or Ala120. Compared with hPAR4 Ala120 mice, hPAR4 Thr120 mice had worse stroke outcomes, mediated in part by enhanced platelet activation and platelet-neutrophil interactions. Analyses of 7,620 Black subjects with 487 incident ischemic strokes demonstrated the AA genotype was a risk for incident ischemic stroke and worse functional outcomes. In humanized mice, ticagrelor with or without aspirin improved stroke outcomes in hPAR4 Ala120 mice, but not in hPAR4 Thr120 mice. P selectin blockade improved stroke outcomes and reduced platelet-neutrophil interactions in hPAR4 Thr120 mice. Our results may explain some of the racial disparity in stroke and support the need for studies of nonstandard antiplatelet therapies for patients expressing PAR4 Thr120.

Methods of a Study to Assess the Contribution of Cerebral Small Vessel Disease and Dementia Risk Alleles to Racial Disparities in Vascular Cognitive Impairment and Dementia

Background Non-Hispanic Black adults have a higher proportion of vascular cognitive impairment and Alzheimer's disease and related dementias compared with non-Hispanic White adults that may be due to differences in the burden of cerebral small vessel disease and risk alleles for Alzheimer's disease and related dementias. We describe here the methods of an ancillary study to the REGARDS (Reason for Geographic and and Racial Difference in Stroke) study, which will examine the role of magnetic resonance imaging markers of cerebral small vessel disease and vascular as well as genetic risk factors for Alzheimer's disease and related dementias in racial disparity in the prevalence and trajectory of vascular cognitive impairment and dementia in non-Hispanic White and non-Hispanic Black participants. Methods In participants with no prior history of stroke who had an incident stroke or transient ischemic attack after enrollment in the study, magnetic resonance imaging scans will be evaluated using the Standards for Reporting Vascular Changes on Neuroimaging international consensus criteria and automated analysis pipelines for quantification of cerebral small vessel disease. Participants will be genotyped for APOE ε4 and TREM2 risk alleles for Alzheimer's disease and related dementias. The 6-item screener will define global cognitive function and be the primary cognitive outcome. Conclusions With at least 426 non-Hispanic Black and 463 non-Hispanic White participants who have at least 2 prior and 2 poststroke or transient ischemic attack cognitive assessments, we will have at least 80% power to detect a minimum effect size of 0.09 SD change in Z score, with correction for as many as 20 tests (ie, at P<0.0025, after adjusting for up to 20 covariates) for cognitive decline.

An analysis of racial inequities in emergency department triage among patients with stroke-like symptoms in the United States

BACKGROUND

Racial inequities exist in treatment and outcomes in patients with acute stroke.

OBJECTIVES

Our objective was to determine if racial inequities exist in the time-lapse between patient presentation and provider assessment in patients with stroke-like symptoms in Emergency Departments (ED) across the U.S.

METHODS

This study is a retrospective, observational study of the National Hospital Ambulatory Medical Care Survey (NHAMCS) 2014-2018. We identified visits with stroke-like symptoms and stratified the proportion of door-to-provider (DTP) times by racial groups. We used broad and narrow definitions of stroke-like symptoms. We performed bivariate and multivariate analyses using race and clinical and demographic characteristics as covariates.

RESULTS

Between 2014-2018, there were an average of 138.58 million annual ED visits. Of the total ED visits, 0.36% to 7.39% of the ED visits presented with stroke-like symptoms, and the average DTP time ranged from 39 to 49 min. The proportion of the visits with a triage level of 1 (immediate) or 2 (emergent) ranged from 16.03% to 23.27% for stroke-like symptoms. We did not find statistically significant racial inequities in DTP or ED triage level. We found significantly longer DTP times in non-Hispanic blacks (15.88 min, 95% CI: 4.29-27.48) and Hispanics (by 14.77 min, 95% CI: 3.37-26.16) than non-Hispanic whites that presented with atypical stroke-like symptoms. We observed that non-Hispanic whites were significantly more diagnosed with a stroke/TIA than other racial minority groups (p = 0.045) for atypical stroke-like symptoms.

CONCLUSION

In our population-based analysis, we did not identify systemic racial inequities in the DTP times or ED triage level at ED triage for stroke-like symptoms.

Acetylglutamine Differentially Associated with First-Time Versus Recurrent Stroke

Approximately one-quarter of strokes occur in individuals with prior stroke. Despite the advancement in secondary stroke prevention, the long-term risk of recurrent stroke has remained unchanged. The objective of this study was to identify metabolite risk markers that are associated with recurrent stroke. We performed targeted metabolomic profiling of 162 metabolites by liquid chromatography-tandem mass spectrometry in baseline plasma in a stroke case-cohort study nested within the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, an observational cohort study of 30,239 individuals aged 45 and older enrolled in 2003-2007. Weighted Cox proportional hazard models were used to identify metabolites that had a differential effect on first-time versus recurrent stroke using an interaction term between metabolite and prior stroke at baseline (yes or no). The study included 1391 incident stroke cases identified during 7.1 ± 4.5 years of follow-up and 1050 participants in the random cohort sample. Among 162 metabolites, 13 candidates had a metabolite-by-prior stroke interaction at a p-value <0.05, with one metabolite, acetylglutamine, surpassing the Bonferroni adjusted p-value threshold (p for interaction = 5.78 × 10-5). In an adjusted model that included traditional stroke risk factors, acetylglutamine was associated with recurrent stroke (HR = 2.27 per SD increment, 95% CI = 1.60-3.20, p = 3.52 × 10-6) but not with first-time stroke (HR = 0.96 per SD increment, 95% CI = 0.87-1.06, p = 0.44). Acetylglutamine was associated with recurrent stroke but not first-time stroke, independent of traditional stroke risk factors. Future studies are warranted to elucidate the pathogenesis of acetylglutamine and recurrent stroke risk.

Racial disparities in functional outcomes following mechanical thrombectomy in a cohort of patients with ischemic stroke

BACKGROUND

Non-Hispanic Black (NHB) patients experience increased prevalence of stroke risk factors and stroke incidence compared with non-Hispanic White (NHW) patients. However, little is known about >90-day post-stroke functional outcomes following mechanical thrombectomy.

OBJECTIVE

To describe patient characteristics, evaluate stroke risk factors, and analyze the adjusted impact of race on long-term functional outcomes to better identify and limit sources of disparity in post-stroke care.

METHODS

We retrospectively reviewed 326 patients with ischemic stroke who underwent thrombectomy at two centers between 2019 and 2022. Race was self-reported as NHB, NHW, or non-Hispanic Other. Stroke risk factors, insurance status, procedural parameters, and post-stroke functional outcomes were collected. Good outcomes were defined as modified Rankin Scale score ≤2 and/or discharge disposition to home/self-care. To assess the impact of race on outcomes at 3-, 6-, and 12-months' follow-up, we performed univariate and multivariate logistic regression.

RESULTS

Patients self-identified as NHB (42%), NHW (53%), or Other (5%). 177 (54.3%) patients were female; the median (IQR) age was 67.5 (59-77) years. The median (IQR) National Institutes of Health Stroke Scale score was 15 (10-20). On univariate analysis, NHB patients were more likely to have poor short- and long-term functional outcomes, which persisted on multivariate analysis as significant at 3 and 6 months but not at 12 months (3 months: OR=2.115, P=0.04; 6 months: OR=2.423, P=0.048; 12 months: OR=2.187, P=0.15). NHB patients were also more likely to be discharged to rehabilitation or hospice/death than NHW patients after adjusting for confounders (OR=1.940, P=0.04).

CONCLUSIONS

NHB patients undergoing thrombectomy for ischemic stroke experience worse 3- and 6-month functional outcomes than NHW patients after adjusting for confounders. Interestingly, this disparity was not detected at 12 months. Future research should focus on identifying social determinants in the short-term post-stroke recovery period to improve parity in stroke care.

Twenty-Year Disparity Trends in United States Stroke Death Rate by Age, Race/Ethnicity, Geography, and Socioeconomic Status

BACKGROUND AND OBJECTIVES

In 2017, the Centers for Disease Control and Prevention (CDC) issued an alert that, after decades of consistent decline, the stroke death rate levelled off in 2013, particularly in younger individuals and without clear origin. The objective of this analysis was to understand whether social determinants of health have influenced trends in stroke mortality.

METHODS

We performed a longitudinal analysis of county-level ischemic and hemorrhagic stroke death rate per 100,000 adults from 1999 to 2018 using a Bayesian spatiotemporally smoothed CDC dataset stratified by age (35-64 years [younger] and 65 years or older [older]) and then by county-level social determinants of health. We reported stroke death rate by county and the percentage change in stroke death rate during 2014-2018 compared with that during 2009-2013.

RESULTS

We included data from 3,082 counties for younger individuals and 3,019 counties for older individuals. The stroke death rate began to increase for younger individuals in 2013 (p < 0.001), and the slope of the decrease in stroke death rate tapered for older individuals (p < 0.001). During the 20-year period of our study, counties with a high social deprivation index and ≥10% Black residents consistently had the highest rates of stroke death in both age groups. Comparing stroke death rate during 2014-2018 with that during 2009-2013, larger increases in younger individuals' stroke death rate were seen in counties with ≥90% (vs <90%) non-Hispanic White individuals (3.2% mean death rate change vs 1.7%, p < 0.001), rural (vs urban) populations (2.6% vs 2.0%, p = 0.019), low (vs high) proportion of medical insurance coverage (2.9% vs 1.9%, p = 0.002), and high (vs low) substance abuse and suicide mortality (2.8 vs 1.9%, p = 0.008; 3.3% vs 1.5%, p < 0.001). In contrast to the younger individuals, in older individuals, the associations with increased death rates were with more traditional social determinants of health such as the social deprivation index, urban location, unemployment rate, and proportion of Black race and Hispanic ethnicity residents.

DISCUSSION

Improvements in the stroke death rate in the United States are slowing and even reversing in younger individuals and many US counties. County-level increases in stroke death rate were associated with distinct social determinants of health for younger vs older individuals. These findings may inform targeted public health strategies.

Traumatic Brain Injury and Long-Term Risk of Stroke Among US Military Veterans

BACKGROUND

Traumatic brain injury (TBI) is associated with significant morbidity, but the association of TBI with long-term stroke risk in diverse populations remains less clear. Our objective was to examine the long-term associations of TBI with stroke and to investigate potential differences by age, sex, race and ethnicity, and time since TBI diagnosis.

METHODS

Retrospective cohort study of US military veterans aged 18+ years receiving healthcare in the Veterans Health Administration system between October 1, 2002 and September 30, 2019. Veterans with TBI were matched 1:1 to veterans without TBI on age, sex, race and ethnicity, and index date, yielding 306 796 veterans with TBI and 306 796 veterans without TBI included in the study. In primary analyses, Fine-Gray proportional hazards models adjusted for sociodemographics and medical/psychiatric comorbidities were used to estimate the association between TBI and stroke risk, accounting for the competing risk of mortality.

RESULTS

Participants were a mean age of 50 years, 9% were female, and 25% were of non-White race and ethnicity. Overall, 4.7% of veterans developed a stroke over a median follow-up of 5.2 years. Veterans with TBI had 1.69 times (95% CI, 1.64-1.73) increased risk of any stroke (ischemic or hemorrhagic) compared to veterans without TBI. This increased risk was highest in the first-year post-TBI diagnosis (hazard ratio [HR], 2.16 [95% CI, 2.03-2.29]) but remained elevated for 10+ years. Similar patterns were observed for secondary outcomes, with associations of TBI with hemorrhagic stroke (HR, 3.92 [95% CI, 3.59-4.29]) being stronger than with ischemic stroke (HR, 1.56 [95% CI, 1.52-1.61]). Veterans with both mild (HR, 1.47 [95% CI, 1.43-1.52]) and moderate/severe/penetrating injury (HR, 2.02 [95% CI, 1.96-2.09]) had increased risk of stroke compared to veterans without TBI. Associations of TBI with stroke were stronger among older compared to younger individuals (P interaction-by-age<0.001) and were weaker among Black veterans compared to other race and ethnicities (P interaction-by-race<0.001).

CONCLUSIONS

Veterans with prior TBI are at increased long-term risk for stroke, suggesting they may be an important population to target for primary stroke prevention measures.

20-year trends in multimorbidity by race/ethnicity among hospitalized patient populations in the United States

BACKGROUND

The challenges presented by multimorbidity continue to rise in the United States. Little is known about how the relative contribution of individual chronic conditions to multimorbidity has changed over time, and how this varies by race/ethnicity. The objective of this study was to describe trends in multimorbidity by race/ethnicity, as well as to determine the differential contribution of individual chronic conditions to multimorbidity in hospitalized populations over a 20-year period within the United States.

METHODS

This is a serial cross-sectional study using the Nationwide Inpatient Sample (NIS) from 1993 to 2012. We identified all hospitalized patients aged ≥ 18 years old with available data on race/ethnicity. Multimorbidity was defined as the presence of 3 or more conditions based on the Elixhauser comorbidity index. The relative change in the proportion of hospitalized patients with multimorbidity, overall and by race/ethnicity (Black, White, Hispanic, Asian/Pacific Islander, Native American) were tabulated and presented graphically. Population attributable fractions were estimated from modified Poisson regression models adjusted for sex, age, and insurance type. These fractions were used to describe the relative contribution of individual chronic conditions to multimorbidity over time and across racial/ethnic groups.

RESULTS

There were 123,613,970 hospitalizations captured within the NIS between 1993 and 2012. The prevalence of multimorbidity increased in all race/ethnic groups over the 20-year period, most notably among White, Black, and Native American populations (+ 29.4%, + 29.7%, and + 32.0%, respectively). In both 1993 and 2012, Black hospitalized patients had a higher prevalence of multimorbidity (25.1% and 54.8%, respectively) compared to all other race/ethnic groups. Native American populations exhibited the largest overall increase in multimorbidity (+ 32.0%). Furthermore, the contribution of metabolic diseases to multimorbidity increased, particularly among Hispanic patients who had the highest population attributable fraction values for diabetes without complications (15.0%), diabetes with complications (5.1%), and obesity (5.8%).

CONCLUSIONS

From 1993 to 2012, the secular increases in the prevalence of multimorbidity as well as changes in the differential contribution of individual chronic conditions has varied substantially by race/ethnicity. These findings further elucidate the racial/ethnic gaps prevalent in multimorbidity within the United States.

PRIOR PRESENTATIONS

Preliminary finding of this study were presented at the Society of General Internal Medicine (SGIM) Annual Conference, Washington, DC, April 21, 2017.

Gut microbiota-associated metabolites and risk of ischemic stroke in REGARDS

Several metabolite markers are independently associated with incident ischemic stroke. However, prior studies have not accounted for intercorrelated metabolite networks. We used exploratory factor analysis (EFA) to determine if metabolite factors were associated with incident ischemic stroke. Metabolites (n = 162) were measured in a case-control cohort nested in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, which included 1,075 ischemic stroke cases and 968 random cohort participants. Cox models were adjusted for age, gender, race, and age-race interaction (base model) and further adjusted for the Framingham stroke risk factors (fully adjusted model). EFA identified fifteen metabolite factors, each representing a well-defined metabolic pathway. Of these, factor 3, a gut microbiome metabolism factor, was associated with an increased risk of stroke in the base (hazard ratio per one-unit standard deviation, HR = 1.23; 95%CI = 1.15-1.31; P = 1.98 × 10-10) and fully adjusted models (HR = 1.13; 95%CI = 1.06-1.21; P = 4.49 × 10-4). The highest tertile had a 45% increased risk relative to the lowest (HR = 1.45; 95%CI = 1.25-1.70; P = 2.24 × 10-6). Factor 3 was also associated with the Southern diet pattern, a dietary pattern previously linked to increased stroke risk in REGARDS (β = 0.11; 95%CI = 0.03-0.18; P = 8.75 × 10-3). These findings highlight the role of diet and gut microbial metabolism in relation to incident ischemic stroke.

The design and rationale of a multicenter real-world trial: The Southeastern Collaboration to Improve Blood Pressure Control in the US Black Belt - Addressing the Triple Threat

BACKGROUND

Impoverished African Americans (AA) with hypertension face poor health outcomes.

PURPOSE

To conduct a cluster-randomized trial testing two interventions, alone and in combination, to improve blood pressure (BP) control in AA with persistently uncontrolled hypertension.

METHODS

We engaged primary care practices serving rural Alabama and North Carolina residents, and in each practice we recruited approximately 25 AA adults with persistently uncontrolled hypertension (mean systolic BP >140 mmHg over the year prior to enrollment plus enrollment day BP assessed by research assistants ≥140/90 mmHg). Practices were randomized to peer coaching (PC), practice facilitation (PF), both PC and PF (PC + PF), or enhanced usual care (EUC). Coaches met with participants from PC and PC + PF practices weekly for 8 weeks then monthly over one year, discussing lifestyle changes, medication adherence, home monitoring, and communication with the healthcare team. Facilitators met with PF and PC + PF practices monthly to implement ≥1 quality improvement intervention in each of four domains. Data were collected at 0, 6, and 12 months.

RESULTS

We recruited 69 practices and 1596 participants; 18 practices (408 participants) were randomized to EUC, 16 (384 participants) to PF, 19 (424 participants) to PC, and 16 (380 participants) to PC + PF. Participants had mean age 57 years, 61% were women, and 56% reported annual income <$20,000.

LIMITATIONS

The PF intervention acts at the practice level, possibly missing intervention effects in trial participants. Neither PC nor PF currently has established clinical reimbursement mechanisms.

CONCLUSIONS

This trial will fill evidence gaps regarding practice-level vs. patient-level interventions for rural impoverished AA with uncontrolled hypertension.

Association of Circulating Metabolites With Racial Disparities in Hypertension and Stroke in the REGARDS Study

BACKGROUND AND OBJECTIVES

In the United States, the risk of stroke is greater among Black compared with that among White individuals. However, the reasons for the difference in stroke incidence are not fully elucidated. We aimed to identify metabolites that account for higher prevalent hypertension and incident ischemic stroke among Black adults.

METHODS

We used a stroke case cohort nested within the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. Targeted metabolomic profiling of 162 plasma metabolites was performed by liquid chromatography-tandem mass spectrometry. We identified metabolites that were associated with prevalent hypertension and incident ischemic stroke and mediated the relationship between hypertension and ischemic stroke by weighted logistic regression, Cox proportional hazard model, and inverse odds ratio weighting mediation analysis.

RESULTS

Incident ischemic stroke cases adjudicated through April 1, 2019 (n = 1,075) were included in the study. The random cohort sample was derived from the full cohort using stratified sampling (n = 968). Among 162 metabolites, gluconic acid was associated with prevalent hypertension in Black adults (odds ratio [OR] 1.86, 95% CI 1.39-2.47, p = 2.58 × 10-5) but not in White adults (OR 1.00, 95% CI 0.80-1.24, p = 0.97; p for interaction = 4.57 × 10-4). Gluconic acid also demonstrated an association with incident ischemic stroke among Black participants (hazard ratio [HR] 1.53, 95% CI 1.28-1.81, p = 1.76 × 10-6) but not White participants (HR 1.16, 95% CI 1.00-1.34, p = 0.057; p for interaction = 0.019). In mediation analysis, gluconic acid mediated 25.4% (95% CI 4.1%-46.8%, p = 0.02) of the association between prevalent hypertension and incident ischemic stroke among Black individuals. Specific socioeconomic factors were linked to elevated gluconic acid level among Black adults in multivariable analysis, including a Southern dietary pattern (β = 0.18, 95% CI 0.08-0.28, p < 0.001), lower educational attainment (β = 0.45, 95% CI 0.19-0.72, p = 0.001), and a lack of exercise (β = 0.26, 95% CI 0.01-0.51, p = 0.045).

DISCUSSION

Gluconic acid is associated with prevalent hypertension and incident ischemic stroke and mediates the relationship between hypertension and ischemic stroke in Black but not White adults. Gluconic acid is a biomarker that is associated with social determinants of health including a Southern diet, low educational attainment, and low physical activity.

Rural versus Urban Residence in Adulthood and Incident Cognitive Impairment

INTRODUCTION

Rural versus urban living is a social determinant of cognitive health. We estimated the association of rural versus urban residence in the USA with incident cognitive impairment (ICI) and assessed effect heterogeneity by sociodemographic, behavioral, and clinical factors.

METHODS

The Reasons for Geographic and Racial Differences in Stroke Study (REGARDS) is a population-based prospective observational cohort of 30,239 adults, 57% female, 36% Black, aged 45+ years, sampled from 48 contiguous states in the USA in 2003-2007. We analyzed 20,878 participants who at baseline were cognitively intact with no history of stroke and had ICI assessed on average 9.4 years later. We classified participants' home addresses at baseline as urban (population ≥50,000), large rural (10,000-49,999), or small rural (≤9,999) by Rural-Urban Commuting Area codes. We defined ICI as ≥1.5 SD below the mean on at least 2 of the following tests: word list learning, word list delayed recall, and animal naming.

RESULTS

Participants' home addresses were 79.8% urban, 11.7% large rural, and 8.5% small rural. ICI occurred in 1,658 participants (7.9%). Small rural residents had higher odds of ICI than urban residents, adjusted for age, sex, race, region, and education (OR = 1.34 [95% CI: 1.10, 1.64]), and after further adjustment for income, health behaviors, and clinical characteristics (OR = 1.24 [95% CI: 1.02, 1.53]). Former smoking versus never, nondrinking versus light alcohol drinking, no exercise versus ≥4 times/week, CES-D depressive symptom score of 2 versus 0, and fair versus excellent self-rated health had stronger associations with ICI in small rural areas than in urban areas. For example, in urban areas, lack of exercise was not associated with ICI (OR = 0.90 [95% CI: 0.77, 1.06]); however, lack of exercise combined with small rural residence was associated with 1.45 times the odds of ICI compared with ≥4 bouts of exercise/week in urban areas (95% CI: 1.03, 2.03). Overall, large rural residence was not associated with ICI; however, black race, hypertension, and depressive symptoms had somewhat weaker associations with ICI, and heavy alcohol drinking a stronger association with ICI, in large rural areas than in urban areas.

CONCLUSION

Small rural residence was associated with ICI among USA adults. Further research to better understand why rural residents are at higher risk for developing ICI and mechanisms to ameliorate that risk will support efforts to advance rural public health.

Sex and Racial Disparity in Outcome of Aneurysmal Subarachnoid Hemorrhage in the United States: A 20-Year Analysis

BACKGROUND

Aneurysmal subarachnoid hemorrhage is associated with high rate of morbidity and mortality. We aimed to assess prognostic impact of sex, race, and ethnicity in these patients.

METHODS

Nationwide Inpatient Sample (2000-2019) was used to identify patients presenting with aneurysmal subarachnoid hemorrhage as primary diagnosis. Patient age, sex, race/ethnicity, insurance status, socioeconomic status, comorbidities, type of the hospital, and treatment modality used for aneurysm repair were extracted. The previously validated Nationwide Inpatient Sample Subarachnoid Hemorrhage Severity Scale was used to estimate the clinical severity. Discharge destination and in-hospital mortality was used as outcome measured. The impact of race/ethnicity and sex on clinical outcome was analyzed using multivariate regression models.

RESULTS

A total of 161 086 patients with aneurysmal subarachnoid hemorrhage were identified. Mean age was 55.0±13.8 years. Sixty-nine percent of the patients were female, 60% White patients, and 17% Black patients. There was no difference in the Nationwide Inpatient Sample Subarachnoid Hemorrhage Severity Scale score between the 2 sexes. Women had significantly lower odds of good clinical outcome (defined as discharge to home or acute rehabilitation facility; RR, 0.83 [95% CI, 0.74-0.94]; P=0.004). Hispanic patients (RR, 1.12 [95% CI, 1.07-1.17]; P<0.001) had higher odds of excellent clinical outcome compared with White patients, and lower risk of mortality were observed in Black patients (RR, 0.73 [95% CI, 0.66-0.81]) and Hispanic patients (RR, 0.78 [95% CI, 0.70-0.86]) compared with the White patients.

CONCLUSIONS

In this nationally representative study, women were less likely to have excellent outcomes following aneurysmal subarachnoid hemorrhage, and White patients had disproportionately higher likelihood of worse clinical outcomes. Lower rates of mortality were seen among Black and Hispanic patients.

Age-Related Differences in the Role of Risk Factors for Ischemic Stroke

BACKGROUND AND OBJECTIVES

Reports assessing the association of stroke risk factors with incident stroke have generally assumed a uniform magnitude of associations across the age spectrum, an assumption we assess in this report.

METHODS

Participants enrolled 2003-2007 in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort study who were stroke free at baseline were followed for incident stroke. Associations of traditional stroke risk factors with incident stroke were assessed using (1) proportional hazards analysis based on the baseline age of the participant and (2) Poisson regression analysis assessing associations based on the changing age of the participant during their follow-up (age at exposure). In each analysis, age strata were selected to have a similar number of strokes in each stratum, specifically 45-64, 65-73, and 74+ years for the proportional hazards analysis and 45-69, 70-79, and 80+ years for Poisson regression.

RESULTS

A total of 1,405 ischemic stroke events occurred among 28,235 participants over a median follow-up of 11.3 years, with a total of 276,074 person-years exposure. For both analytic approaches, the magnitude of the association with stroke was significantly less at older ages for diabetes (hazard or relative risk decreasing from ≈2.0 in younger strata to ≈1.3 in older strata), heart disease (from ≈2.0 to ≈1.3), and hypertension defined at a threshold of 140/90 mm Hg (from ≈1.80 to ≈1.50); however, there was no age-related difference in the magnitude of the association for smoking, atrial fibrillation, or left ventricular hypertrophy.

DISCUSSION

Hypertension and diabetes are 2 of the more important risk factors for stroke; however, their association with stroke risk appears substantially less at older ages. That the magnitude of the association for smoking, atrial fibrillation, and left ventricular hypertrophy does not decrease with age suggests their relative importance in determining stroke risk likely increases with age.

Racial and Ethnic Disparities in Stroke Prevention for Atrial Fibrillation

Racial and ethnic disparities in health care are well documented, although often underappreciated. In the setting of atrial fibrillation, stroke risk and severity may be higher in underrepresented ethnic populations. Additionally, the risk of bleeding is not uniform, and pharmacogenetics play an important role in anticoagulant therapy. In this narrative review, we discuss the complex issues surrounding stroke prevention in underrepresented ethnic groups with atrial fibrillation.

Plasma Metabolites Link Dietary Patterns to Stroke Risk

OBJECTIVE

While dietary intake is linked to stroke risk, surrogate markers that could inform personalized dietary interventions are lacking. We identified metabolites associated with diet patterns and incident stroke in a nested cohort from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study.

METHODS

Levels of 162 metabolites were measured in baseline plasma from stroke cases (n = 1,198) and random controls (n = 904). We examined associations between metabolites and a plant-based diet pattern previously linked to reduced stroke risk in REGARDS. Secondary analyses included 3 additional stroke-associated diet patterns: a Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Southern diet. Metabolites were tested using Cox proportional hazards models with incident stroke as the outcome. Replication was performed in the Jackson Heart Study (JHS). Inverse odds ratio-weighted mediation was used to determine whether metabolites mediated the association between a plant-based diet and stroke risk.

RESULTS

Metabolites associated with a plant-based diet included the gut metabolite indole-3-propionic acid (β = 0.23, 95% confidence interval [CI] [0.14, 0.33], p = 1.14 × 10-6 ), guanosine (β = -0.13, 95% CI [-0.19, -0.07], p = 6.48 × 10-5 ), gluconic acid (β = -0.11, 95% CI [-0.18, -0.04], p = 2.06 × 10-3 ), and C7 carnitine (β = -0.16, 95% CI [-0.24, -0.09], p = 4.14 × 10-5 ). All of these metabolites were associated with both additional diet patterns and altered stroke risk. Mediation analyses identified guanosine (32.6% mediation, p = 1.51 × 10-3 ), gluconic acid (35.7%, p = 2.28 × 10-3 ), and C7 carnitine (26.2%, p = 1.88 × 10-2 ) as mediators linking a plant-based diet to reduced stroke risk.

INTERPRETATION

A subset of diet-related metabolites are associated with risk of stroke. These metabolites could serve as surrogate markers that inform dietary interventions. ANN NEUROL 2023;93:500-510.

Racial disparities in post-transplant stroke and mortality following stroke in adult cardiac transplant recipients in the United States

Black heart transplant recipients have a higher mortality rate than white recipients 6-12 months after transplant. Whether there are racial disparities in post-transplant stroke incidence and all-cause mortality following post-transplant stroke among cardiac transplant recipients is unknown. Using a nationwide transplant registry, we assessed the association between race and incident post-transplant stroke using logistic regression and the association between race and mortality among adults who survived a post-transplant stroke using Cox proportional hazards regression. We found no evidence of an association between race and the odds of post-transplant stroke (OR = 1.00, 95% CI: 0.83-1.20). The median survival time of those with a post-transplant stroke in this cohort was 4.1 years (95% CI: 3.0, 5.4). There were 726 deaths among the 1139 patients with post-transplant stroke, including 127 deaths among 203 Black patients and 599 deaths among 936 white patients. Among post-transplant stroke survivors, Black transplant recipients experienced a 23% higher rate of mortality compared to white recipients (HR = 1.23, 95% CI: 1.00-1.52). This disparity is strongest in the period beyond the first 6 months and appears to be mediated by differences in the post-transplant setting of care between Black and white patients. The racial disparity in mortality outcomes was not evident in the past decade. The improved survival of Black patients in the recent decade may reflect overall protocol improvements for heart transplant recipients irrespective of race, such as advancements in surgical techniques and immediate postoperative care as well as increased awareness about reducing racial disparities.

Sleep Health as a Determinant of Disparities in Stroke Risk and Health Outcome

Sleep is essential to human survival and overall vascular health. Sleep health encompasses the objective and subjective qualities associated with one's daily pattern of sleep and wakefulness and has become a growing clinical and public health concern. Impaired sleep duration and quality can increase stroke risk and mediate the relationship between the physical aspects of an individual's environment and disparities in stroke incidence. Here, we review observational studies evaluating the association between sleep health and cerebrovascular disease. We assess the influence on sleep of the physical environment, including the ambient environment with noise levels and the built environment. We also describe the influences on sleep health and stroke risk of social determinants of health, including the chronic stressor of racial discrimination. Finally, we discuss how changes in historical neighborhood characteristics or societal policies can influence the social factors affecting sleep health and stroke risk among socioeconomically disadvantaged groups or ethnic and racial minorities. Given the regional and racial or ethnic differences in stroke risk across the United States, an understanding of novel vascular risk factors, such as the multifaceted role of sleep health, will be critical to develop effective public policies to improve population health.