Ischemic stroke/transient ischemic attack events and carotid artery disease in the absence of or with minimal coronary artery calcification: Results from the Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

The association between minimally elevated coronary artery calcification (CAC) and cerebrovascular disease is not well known. We assessed whether individuals with minimal CAC (Agatston scores of 1-10) have higher ischemic stroke or transient ischemic attack (TIA) frequencies compared with those with no CAC. We also investigated the relative prevalence of carotid atherosclerosis in these two groups.

METHODS

A total of 3924 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) without previous cardiovascular events, including stroke, and with baseline CAC scores of 0-10 were followed for the occurrence of incident ischemic stroke/TIA. We used carotid ultrasound to detect carotid artery plaques and to measure the intima-media thickness (IMT).

RESULTS

During a median follow-up of 13.2 years, 130 participants developed incident ischemic stroke/TIA. There was no significant difference in the ischemic stroke/TIA incidence between those with minimal CAC and no CAC (3.7 versus 2.7 per 1000 person-years). In participants with minimal CAC, we observed a significant association of the condition with an internal carotid artery (ICA) that had a greater-than-average IMT (ICA-IMT; β = 0.071, p = 0.001) and a higher odds ratio (OR) for carotid artery plaques (OR 1.46; with a 95% confidence interval [CI] of 1.18-1.80; p < 0.001).

CONCLUSIONS

A CAC score of 0-10 is associated with a low rate of ischemic stroke/TIA, and thus a minimal CAC score is not a valuable predictive marker for ischemic stroke/TIA. A minimal CAC score may, however, provide an early and asymptomatic sign of carotid artery disease.

A Targeted Self-Management Approach for Reducing Stroke Risk Factors in African American Men Who Have Had a Stroke or Transient Ischemic Attack

PURPOSE

This study compared a novel self-management (TargetEd MAnageMent Intervention [TEAM]) versus treatment as usual (TAU) to reduce stroke risk in African American (AA) men.

DESIGN

Six-month prospective randomized controlled trial with outcomes evaluated at baseline, 3 months, and 6 months.

SETTING

Academic health center.

PARTICIPANTS

Thirty-eight (age < 65) AA men who had a stroke or transient ischemic attack and a Barthel index score of >60 were randomly assigned to TEAM (n = 19) or TAU (n = 19).

INTERVENTION

Self-management training, delivered in 1 individual and 4 group sessions (over 3 months).

MEASURES

Blood pressure, glycosylated hemoglobin (HbA1c), lipids, medication adherence, weight, and standardized measures of health behaviors (diet, exercise, smoking, substances), depression, and quality of life. Qualitative assessments evaluated the perspectives of TEAM participants.

ANALYSIS

T tests for paired differences and nonparametric tests. Thematic content qualitative analysis.

RESULTS

Mean age was 52.1 (standard deviation [SD] = 7.4) and mean body mass index was 31.4 (SD = 7.4). Compared to TAU, TEAM participants had significantly lower mean systolic blood pressure by 24 weeks, and there was also improvement in HbA1c and high-density lipoprotein cholesterol ( P = .03). Other biomarker and health behaviors were similar between groups. Qualitative results suggested improved awareness of risk factors as well as positive effects of group support.

A Pilot Trial of a Lifestyle Intervention for Stroke Survivors: Design of Healthy Eating and Lifestyle after Stroke (HEALS)

BACKGROUND

Stroke survivors have high rates of subsequent cardiovascular and recurrent cerebrovascular events, and mortality. While healthy lifestyle practices - including a diet rich in fruits and vegetables, limited alcohol intake, and regular physical activity - can mitigate these outcomes, few stroke survivors adhere to them. Minorities from socioeconomically disadvantaged communities who obtain care in safety-net health systems experience the most barriers to implementing healthy lifestyle changes after stroke.

PURPOSE

To report the design of Healthy Eating and Lifestyle After Stroke (HEALS), a randomized controlled trial (RCT) was designed to test the feasibility of using a manualized, lifestyle management intervention in a safety-net setting to improve lifestyle practices among ethnically diverse individuals with stroke or transient ischemic attack (TIA).

METHODS

Design: Pilot RCT.

PARTICIPANTS

Inclusion criteria: 1) Adults (≥40 years) with ischemic stroke or TIA (≥ 90 days prior); 2) English- or Spanish-speaking.

SETTING

Outpatient clinic, safety-net setting.

INTERVENTION

Weekly two-hour small group sessions led by an occupational therapist for six weeks. The sessions focused on implementing nutrition, physical activity, and self-management strategies tailored to each participant's goals.

MAIN OUTCOME MEASURES

Body mass index, diet, and physical activity.

CONCLUSIONS

Recruitment for this study is complete. If the HEALS intervention study is feasible and effective, it will serve as a platform for a large-scale RCT that will investigate the efficacy and cost-effectiveness of life management interventions for racially and ethnically diverse, low-income individuals with a history of stroke or TIA who seek healthcare in the safety-net system.

Coronary artery calcium and incident cerebrovascular events in an asymptomatic cohort. The MESA Study

OBJECTIVES

This study assessed the predictive value of coronary artery calcium (CAC) score for cerebrovascular events (CVE) in an asymptomatic multiethnic cohort.

BACKGROUND

The CAC score, a measure of atherosclerotic burden, has been shown to improve prediction of coronary heart disease events. However, the predictive value of CAC for CVE is unclear.

METHODS

CAC was measured at baseline examination of participants (N = 6,779) of MESA (Multi-Ethnic Study of Atherosclerosis) and then followed for an average of 9.5 ± 2.4 years for the diagnosis of incident CVE, defined as all strokes or transient ischemic attacks.

RESULTS

During the follow-up, 234 (3.5%) adjudicated CVE occurred. In Kaplan-Meier analysis, the presence of CAC was associated with a lower CVE event-free survival versus the absence of CAC (log-rank chi-square: 59.8, p < 0.0001). Log-transformed CAC was associated with increased risk for CVE after adjusting for age, sex, race/ethnicity, body mass index, systolic and diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, cigarette smoking status, blood pressure medication use, statin use, and interim atrial fibrillation (hazard ratio [HR]: 1.13 [95% confidence interval (CI): 1.07 to 1.20], p < 0.0001). The American College of Cardiology/American Heart Association-recommended CAC cutoff was also an independent predictor of CVE and strokes (HR: 1.70 [95% CI: 1.24 to 2.35], p = 0.001, and HR: 1.59 [95% CI: 1.11 to 2.27], p = 0.01, respectively). CAC was an independent predictor of CVE when analysis was stratified by sex or race/ethnicity and improved discrimination for CVE when added to the full model (c-statistic: 0.744 vs. 0.755). CAC also improved the discriminative ability of the Framingham stroke risk score for CVE.

CONCLUSIONS

CAC is an independent predictor of CVE and improves the discrimination afforded by current stroke risk factors or the Framingham stroke risk score for incident CVE in an initially asymptomatic multiethnic adult cohort.

Stroke recovery and prevention barriers among young african-american men: potential avenues to reduce health disparities

BACKGROUND

African Americans (AAs) who experience a first time stroke are younger and have double the stroke rate and more poststroke complications than other Americans.

OBJECTIVE

To assess perceived poststroke care barriers among younger AA men and their care partners (CPs) in order to inform the development of acceptable and effective improvements in poststroke care for this high-risk group.

METHODS

Ten community-dwelling AA stroke survivors and 7 of their CPs participated in focus groups and advisory board meetings. Survivors had stroke or transient ischemic attack within 1 year and a Barthel Index score ≯60. In focus groups, using a semi-structured interview guide, survivors and CPs identified self-perceived barriers and facilitators to poststroke care. Thematic analysis of session transcripts and the constant comparative method were used to generate themes.

RESULTS

Survivor age ranged from 34 to 64 years. Mean Barthel score was 95.5. CPs, all AA women, ranged in age from 49 to 61 years. Five CPs were wives, 1 was a fiancée, and 1 was a niece. Participants cited multiple personal, social, and societal stroke recovery challenges. Although hypertension and smoking risks were acknowledged, stress, depression, posttraumatic stress disorder, anger/frustration, personal identity change, and difficulty communicating unique needs as AA men were more frequently noted. Facilitators included family support, stress reduction, and dietary changes.

CONCLUSIONS

Younger AA men and their CPs perceive multiple poststroke care barriers. Biological risk reduction education may not capture all salient aspects of health management for AA stroke survivors. Leveraging family and community strengths, addressing psychological health, and directly engaging patients with health care teams may improve care management.

Chronic stress, depressive symptoms, anger, hostility, and risk of stroke and transient ischemic attack in the multi-ethnic study of atherosclerosis

BACKGROUND AND PURPOSE

This study investigated chronic stress, depressive symptoms, anger, and hostility in relation to incident stroke and transient ischemic attacks in middle-aged and older adults.

METHODS

Data were from the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based cohort study of 6749 adults, aged 45 to 84 years and free of clinical cardiovascular disease at baseline, conducted at 6 US sites. Chronic stress, depressive symptoms, trait anger, and hostility were assessed with standard questionnaires. The primary outcome was clinically adjudicated incident stroke or transient ischemic attacks during a median follow-up of 8.5 years.

RESULTS

One hundred ninety-five incident events (147 strokes; 48 transient ischemic attacks) occurred during follow-up. A gradient of increasing risk was observed for depressive symptoms, chronic stress, and hostility (all P for trend ≤0.02) but not for trait anger (P>0.10). Hazard ratios (HRs) and 95% confidence intervals indicated significantly elevated risk for the highest-scoring relative to the lowest-scoring group for depressive symptoms (HR, 1.86; 95% confidence interval, 1.16-2.96), chronic stress (HR, 1.59; 95% confidence interval, 1.11-2.27), and hostility (HR, 2.22; 95% confidence interval, 1.29-3.81) adjusting for age, demographics, and site. HRs were attenuated but remained significant in risk factor-adjusted models. Associations were similar in models limited to stroke and in secondary analyses using time-varying variables.

CONCLUSIONS

Higher levels of stress, hostility, and depressive symptoms are associated with significantly increased risk of incident stroke or transient ischemic attacks in middle-aged and older adults. Associations are not explained by known stroke risk factors.

Medication adherence and stroke/TIA risk in treated hypertensives: results from the REGARDS study

BACKGROUND

The extent to which low medication adherence in hypertensive individuals contributes to disparities in stroke and transient ischemic attack (TIA) risk is poorly understood.

METHODS

Investigators examined the relationship between self-reported medication adherence and blood pressure (BP) control (<140/90 mm Hg), Framingham Stroke Risk Score, and physician-adjudicated stroke/TIA incidence in treated hypertensive subjects (n = 15,071; 51% black; 57% in Stroke Belt) over 4.9 years in the national population-based REGARDS cohort study.

RESULTS

Mean systolic BP varied from 130.8 ± 16.2 mm Hg in those reporting high adherence to 137.8 ± 19.5 mm Hg in those reporting low adherence (P for trend < .0001). In logistic regression models, each level of worsening medication adherence was associated with significant and increasing odds of inadequately controlled BP (≥140/90 mm Hg; score = 1, odds ratio [95% confidence interval], 1.20 [1.09-1.30]; score = 2, 1.27 [1.08-1.49]; score = 3 or 4, 2.21 [1.75-2.78]). In hazard models using systolic BP as a mediator, those reporting low medication adherence had 1.08 (1.04-1.14) times greater risk of stroke and 1.08 (1.03-1.12) times greater risk of stroke or TIA.

CONCLUSION

Low medication adherence was associated with inadequate BP control and an increased risk of incident stroke or TIA.

Defining cause of death in stroke patients: The Brain Attack Surveillance in Corpus Christi Project

Stroke mortality is an important national health statistic and represents a frequent endpoint for epidemiologic studies. Several methods have been used to determine cause of death after stroke, but their agreement and reliability are unknown. Two hundred consecutive deaths of transient ischemic attack or ischemic stroke patients were identified (January 2000-September 2001) from an ongoing population-based stroke surveillance study in Texas, The Brain Attack Surveillance in Corpus Christi Project. Two neurologists independently recorded the cause of death based on two methods: 1) determining the underlying cause of death as defined by the World Health Organization, and 2) determining whether the death was stroke related. Kappa statistics with 95% confidence intervals were calculated by comparing agreement between methods within reviewers and between reviewers within methods. Agreement between the two cause-of-death-determination methods for each neurologist was 0.41 (95% confidence interval (CI): 0.31, 0.51) and 0.47 (95% CI: 0.38, 0.58), respectively. Agreement between neurologists for the underlying-cause-of-death method was 0.46 (95% CI: 0.32, 0.60); for the stroke-related method, it was 0.63 (95% CI: 0.52, 0.75). Accurate, reliable determinations of cause of death after stroke/transient ischemic attack are not currently feasible. More research is needed to identify a reliable process for coding cause of death from stroke.

Quality of hospital care in African American and white patients with ischemic stroke and TIA

OBJECTIVE

To examine whether differences exist in the in-hospital diagnostic evaluation and treatment of African American and white patients with ischemic stroke (IS) and TIA.

METHODS

The authors used a state-wide hospital-based stroke registry prototype designed to measure and track the quality of acute stroke care. Weighted descriptive statistics for each racial group are reported for the following variables, which were deemed to be potential confounders of the association between race and the quality of stroke care: age, gender, insurance status, emergency medical services arrival, functional status on presentation, modified Rankin score at discharge, stroke subtype, neurologist involved in care, and stroke pathway utilization. The magnitude and significance of the associations between race and each quality indicator of in-hospital acute stroke care were determined by separate multiple logistic regression models, adjusting for all potential confounding variables.

RESULTS

Among patients admitted with IS and TIA who were alive at discharge (n = 1,837), 340 (18.5%) were African American and 1497 (81.5%) were white. After multivariate analysis, African Americans were less likely to have a door-to-CT time of less than 25 minutes (odds ratio [OR] 0.13 [CI 0.049 to 0.32]), obtain cardiac monitoring (OR 0.54 [CI 0.29 to 1.03]), undergo dysphagia screening (OR 0.69 [CI 0.50 to 0.95]), and receive smoking cessation counseling (OR 0.27 [CI 0.17 to 0.42]).

CONCLUSIONS

Quality of hospital care for African American and white patients with acute ischemic stroke and TIA was similar in many respects. However, African Americans were less likely to receive a CT within 25 minutes of arrival, cardiac monitoring, dysphagia screening, and smoking cessation counseling.

Methylenetetrahydrofolate Reductase Polymorphisms and Homocysteine-Lowering Effect of Vitamin Therapy in Singaporean Stroke Patients

BACKGROUND AND PURPOSE

Increased plasma total homocysteine (tHcy) levels are a risk factor for stroke and can be reduced with vitamin therapy. However, data on the tHcy-lowering effects of vitamins are limited largely to white populations. Thus, we aimed to determine in Singaporean patients with recent stroke: (1) the efficacy of vitamin therapy (folic acid, vitamin B12, and B6) on lowering tHcy, and (2) whether efficacy is modified by Methylenetetrahydrofolate reductase (MTHFR) gene polymorphism(s).

METHODS

A total of 443 eligible patients were recruited after presenting with ischemic stroke within the past 7 months. Patients were randomized to receive either placebo or vitamins. Fasting blood samples collected at baseline and at 1 year were assayed for levels of plasma tHcy. Patients were genotyped for MTHFR C677T and A1298C polymorphisms.

RESULTS

Mean baseline tHcy was similar in the 2 groups (placebo 13.7 micromol/L; vitamins 14.0 micromol/L; P=0.70). At 1 year, mean tHcy was 14.5 micromol/L in the placebo group compared with 10.7 micromol/L in the vitamin group (difference 3.8 micromol/L; 95% CI, 2.8 to 4.8 micromol/L; P<0.0001). MTHFR C677T genotype was an independent determinant of tHcy levels at baseline (P=0.005), but A1298C was not (P=0.08). Neither polymorphism significantly influenced the effect of vitamin therapy on tHcy at 1 year. The magnitude of the reduction in tHcy levels at 1 year with vitamin therapy was similar, irrespective of MTHFR genotypes.

CONCLUSIONS

Vitamin therapy reduces mean tHcy levels by 3.8 micromol/L in the Singaporean stroke population studied. MTHFR C677T but not A1298C is independently associated with tHcy levels at baseline, and neither impacts the tHcy-lowering effect of vitamins used in this study.

Emergency department evaluation of ischemic stroke and TIA: the BASIC Project

OBJECTIVE

To identify demographic and clinical variables of emergency department (ED) practices in a community-based acute stroke study.

METHODS

By both active and passive surveillance, the authors identified cerebrovascular disease cases in Nueces County, TX, as part of the Brain Attack Surveillance in Corpus Christi (BASIC) Project, a population-based stroke surveillance study, between January 1, 2000, and December 31, 2002. With use of multivariable logistic regression, variables independently associated with three separate outcomes were sought: hospital admission, brain imaging in the ED, and neurologist consultation in the ED. Prespecified variables included age, sex, ethnicity, insurance status, NIH Stroke Scale score, type of stroke (ischemic stroke or TIA), vascular risk factors, and symptom presentation variables. Percentage use of recombinant tissue plasminogen activator (rt-PA) was calculated.

RESULTS

A total of 941 Mexican Americans (MAs) and 855 non-Hispanic whites (NHWs) were seen for ischemic stroke (66%) or TIA (34%). Only 8% of patients received an in-person neurology consultation in the ED, and 12% did not receive any head imaging. TIA was negatively associated with neurology consultations compared with completed stroke (odds ratio [OR] 0.35 [95% CI 0.21 to 0.57]). TIA (OR 0.14 [0.10 to 0.19]) and sensory symptoms (OR 0.59 [0.44 to 0.81]) were also negatively associated with hospital admission. MAs (OR 0.58 [0.35 to 0.98]) were less likely to have neurology consultations in the ED than NHWs. Only 1.7% of patients were treated with rt-PA.

CONCLUSIONS

Neurologists are seldom involved with acute cerebrovascular care in the emergency department (ED), especially in patients with TIA. Greater neurologist involvement may improve acute stroke diagnosis and treatment efforts in the ED.

The influence of ethnicity on warfarin dosage requirement

BACKGROUND

The optimal dose of warfarin varies among individuals, and the prediction of a maintenance dose is difficult. Ethnicity has been reported to influence warfarin dosing.

OBJECTIVE

To quantitate the influence of ethnicity on warfarin dose requirement.

METHODS

We conducted a retrospective cohort study at a university anticoagulation clinic to evaluate the influence of ethnicity on warfarin dose. Inclusion criteria included age > or = 18 years, target international normalized ratio (INR) 2-3, and warfarin management within the clinic for > or = 3 months with a minimum of 5 clinic visits. We collected clinical and demographic data including age, gender, weight, ethnicity, disease states, concomitant medications, indication, weekly warfarin dosage, and INR. To assess potential confounders, multivariate, repeated-measures regression analysis was used to identify and adjust for variables that may influence the maintenance dose of warfarin.

RESULTS

Of the 345 patients who met the inclusion criteria, 27% were Asian American, 6% Hispanic, 54% white, and 14% African American. The adjusted mean (95% CI) weekly warfarin doses for patients with an INR goal of 2 to 3 were Asian Americans 24 mg (21 to 27), Hispanics 31 mg (25 to 37), whites 36 mg (34 to 39), and African Americans 43 mg (39 to 47) (p < 0.001). Additional factors found to influence warfarin dose requirement included age, weight, concomitant use of amiodarone, and diagnosis of venous thromboembolism.

CONCLUSIONS

Warfarin dose requirements vary across ethnic groups even when adjusted for confounding factors, suggesting that genetic variation contributes to interpatient variability.

Racial differences in aortic atheroma in patients undergoing transesophageal echocardiography for unexplained stroke or transient ischemic attack

Racial differences in the prevalence of complex thoracic aortic atheroma were evaluated in 318 patients referred for transesophageal echocardiography after unexplained stroke or transient ischemic attack. African-Americans were found to have fewer complex thoracic aortic atheroma and fewer combined cardiac sources of embolus than Caucasian patients. This finding persists after adjusting for racial differences in atherosclerotic risk factors.

Excess stroke in Mexican Americans compared with non-Hispanic Whites: the Brain Attack Surveillance in Corpus Christi Project

Mexican Americans are the largest subgroup of Hispanics, the largest minority population in the United States. Stroke is the leading cause of disability and third leading cause of death. The authors compared stroke incidence among Mexican Americans and non-Hispanic Whites in a population-based study. Stroke cases were ascertained in Nueces County, Texas, utilizing concomitant active and passive surveillance. Cases were validated on the basis of source documentation by board-certified neurologists masked to subjects' ethnicity. From January 2000 to December 2002, 2,350 cerebrovascular events occurred. Of the completed strokes, 53% were in Mexican Americans. The crude cumulative incidence was 168/10,000 in Mexican Americans and 136/10,000 in non-Hispanic Whites. Mexican Americans had a higher cumulative incidence for ischemic stroke (ages 45-59 years: risk ratio = 2.04, 95% confidence interval: 1.55, 2.69; ages 60-74 years: risk ratio = 1.58, 95% confidence interval: 1.31, 1.91; ages >or=75 years: risk ratio = 1.12, 95% confidence interval: 0.94, 1.32). Intracerebral hemorrhage was more common in Mexican Americans (age-adjusted risk ratio = 1.63, 95% confidence interval: 1.24, 2.16). The subarachnoid hemorrhage age-adjusted risk ratio was 1.57 (95% confidence interval: 0.86, 2.89). Mexican Americans experience a substantially greater ischemic stroke and intracerebral hemorrhage incidence compared with non-Hispanic Whites. As the Mexican-American population grows and ages, measures to target this population for stroke prevention are critical.

Stroke Risk After Transient Ischemic Attack in a Population-Based Setting

BACKGROUND AND PURPOSE

Stroke risk after transient ischemic attack (TIA) has not been examined in an ethnically diverse population-based community setting. The purpose of this study was to identify stroke risk among TIA patients in a population-based cerebrovascular disease surveillance project.

METHODS

The Brain Attack Surveillance in Corpus Christi (BASIC) Project prospectively ascertains stroke and TIA cases in a geographically isolated Southeast Texas County. The community is approximately half Mexican American and half nonHispanic white. Cases are validated by board-certified neurologists using source documentation. Cumulative risk for stroke after TIA was determined using Kaplan-Meier estimates. Cox proportional hazards regression was used to test for associations between stroke risk after TIA and demographics, symptoms, risk factors, and history of stroke/TIA.

RESULTS

BASIC identified 612 TIA cases between January 1, 2000, and December 31, 2002; 60.9% were female and 48.0% were Mexican American. Median age was 73.8 years. Stroke risk within 2 days, 7 days, 30 days, 90 days, and 12 months was 1.64%, 1.97%, 3.15%, 4.03%, and 7.27%, respectively. Stroke risk was not influenced by ethnicity, symptoms, or risk factors.

CONCLUSIONS

Using a population-based design, we found that early stroke risk after TIA was less than previously reported in this bi-ethnic population of Mexican Americans and nonHispanic whites. Approximately half of the 90-day stroke risk after TIA occurred within 2 days.

Racial differences in the prevalence of cardiac sources of embolism in subjects with unexplained stroke or transient ischemic attack evaluated by transesophageal echocardiography

Little is known about the distribution of cardiac sources of embolism among African-Americans with cryptogenic cerebrovascular events. We compared the prevalence of potential cardiac sources of embolism between black and white patients referred to our laboratory for transesophageal echocardiographic (TEE) evaluation of unexplained stroke or transient ischemic attack. Records were reviewed to exclude subjects with high-risk cardiac or vascular disorders likely to explain the index event. Of 297 patients satisfying the inclusion criteria, 196 were white and 87 black. Potential cardioembolic sources were significantly less common in blacks than in whites (adjusted odds ratio [OR], 0.44; 95% confidence interval [CI] 0.26 to 0.75), and related largely to the difference in prevalence of interatrial communication (OR 0.40; 95% CI 0.21 to 0.74). In contrast, African-Americans had a higher prevalence of left ventricular (LV) hypertrophy (OR 3.50; 95% CI 1.97 to 6.22), and particularly, moderate or severe hypertrophy (OR 4.03; 95% CI 1.88 to 9.65) compared with whites. In conclusion, in African-Americans with unexplained cerebrovascular events, the yield of TEE for potential cardioembolic sources, and especially interatrial communication, is lower than in their white counterparts. African-Americans exhibit a substantially higher prevalence of LV hypertrophy, which may be a marker for a higher burden of subclinical cerebrovascular disease involved in the pathogenesis of cryptogenic cerebral ischemia in this population.

Clinical assessment of function among women with a recent cerebrovascular event: a self-reported versus performance-based measure

BACKGROUND

Self-reported functional status is a commonly used health measure in clinical settings, yet the optimal approach for assessing function is often debated.

OBJECTIVE

To examine the agreement between a self-reported and a performance-based measure of function and the relative ability of each measure to predict long-term health outcomes.

DESIGN

Prospective cohort study.

SETTING

20 hospitals in Connecticut and Massachusetts.

PARTICIPANTS

620 postmenopausal women (46 to 91 years of age) who had experienced a stroke or transient ischemic attack.

MEASUREMENTS

A self-reported and a performance-based measure of function were assessed at baseline (before intervention) by using the Barthel index and the Physical Performance Test.

RESULTS

Disagreement between the self-reported and performance-based measure of function was common (slight disagreement, 55.0%; substantial disagreement, 19.3%). Most women (95.4%) overreported their level of function. Women who were more clinically impaired (risk ratio [RR] for more comorbid conditions, 1.52 [95% CI, 1.17 to 1.97]; RR for recent stroke, 2.33 [CI, 1.45 to 3.73]; and RR for cognitive impairment, 1.76 [CI, 1.34 to 2.32]); who were less educated (RR = 1.30 [CI, 1.02 to 1.67]); and who were of nonwhite ethnicity (RR 1.43 [CI, 1.07 to 1.91]) were more likely to overreport their level of function. An impaired performance-based measure of function predicted subsequent stroke or death (hazard ratio, 1.50, [CI, 1.06 to 2.11]); however, an impaired self-reported measure of function was not likely to predict these outcomes.

CONCLUSIONS

Clinicians should be aware that results of self-reported and performance-based measures of function can differ in women who have experienced a recent cerebrovascular event. Although more difficult to collect, results of a performance-based measure may provide information about long-term health outcomes that is not available from a self-reported measure.

Racial variation in treatment for transient ischemic attacks: impact of participation by neurologists

OBJECTIVE

This study evaluates the role of neurologists in explaining African American-white differences in the use of diagnostic and therapeutic services for cerebrovascular disease.

DATA SOURCES/STUDY SETTING

Medicare inpatient hospital records were used to identify a random 20 percent sample of patients age 65 and over hospitalized with a principal diagnosis of TIA between January 1, 1991 and November 30, 1991 (n = 17,437).

STUDY DESIGN

Medicare administrative data were used to identify five outcome measures: noninvasive cerebrovascular tests, cerebral angiography, carotid endarterectomy, anticoagulant therapy (as proxied by outpatient prothrombin time tests), and the specialty of the attending physician (neurologist versus other specialist).

DATA COLLECTION/EXTRACTION METHODS

All Medicare claims were extracted for a 30-day period beginning with the date of admission.

PRINCIPAL FINDINGS

Even after adjusting for patient demographics, comorbidity, ability to pay, and provider characteristics, African American patients were significantly less likely to receive noninvasive cerebrovascular testing, cerebral angiography, or carotid endarterectomy, compared with white patients, and to have a neurologist as their attending physician. At the same time, patients treated by neurologists were more likely to undergo diagnostic testing and less likely to undergo carotid endarterectomy.

CONCLUSIONS

The findings suggest that African American patients with TIA may have less access to services for cerebrovascular disease and that at least some of this may be attributed to less access to neurologists. More research is needed on how patients at risk for stroke are referred to specialists.

Incidence rates of first-ever ischemic stroke subtypes among blacks: a population-based study

BACKGROUND AND PURPOSE

The aim of this study was to determine the incidence rates of ischemic stroke subtypes among blacks.

METHODS

Hospitalized and autopsied cases of stroke and transient ischemic attack among the 187 000 blacks in the 5-county region of greater Cincinnati/northern Kentucky From January 1, 1993, through June 30, 1993, were identified. Incidence rates were age- and sex-adjusted to the 1990 US population. Subtype classification was performed after extensive review of all available imaging, laboratory data, clinical information, and past medical history. Case-control comparisons of risk factors were made with age-, race-, and sex-matched control subjects.

RESULTS

Annual incidence rates per 100 000 for first-ever ischemic stroke subtypes among blacks were as follows: uncertain cause, 103 (95% confidence interval [CI], 80 to 126); cardioembolic, 56 (95% CI, 40 to 73); small-vessel infarct, 52 (95% CI, 36 to 68); large vessel, 17 (95% CI, 8 to 26); and other causes, 17 (95% CI, 9 to 26). Of the patients diagnosed with an infarct of uncertain cause, 31% underwent echocardiography, 45% underwent carotid ultrasound, and 48% had neither. Compared with age-, race-, and sex- (proportionally) matched control subjects from the greater Cincinnati/northern Kentucky region, the attributable risk of hypertension for all causes of first-ever ischemic stroke is 27% (95% CI, 7 to 43); for diabetes, 21% (95% CI, 11 to 29); and for coronary artery disease, 9% (95% CI, 2 to 16). For small-vessel ischemic stroke, the attributable risk of hypertension is 68% (95% CI, 31 to 85; odds ratio [OR], 5.0), and the attributable risk of diabetes is 30% (95% CI, 10 to 45; OR, 4.4). For cardioembolic stroke, the attributable risk of diabetes is 25% (95% CI, 4 to 41; OR, 3.1).

CONCLUSIONS

Stroke of uncertain cause is the most common subtype of ischemic stroke among blacks. Cardioembolic stroke and small-vessel stroke are the most important, identifiable causes of first-ever ischemic stroke among blacks. The incidence rates of cardioembolic and large-vessel stroke are likely underestimated because noninvasive testing of the carotid arteries and echocardiography were not consistently obtained in stroke patients at the 18 regional hospitals. Most small-vessel strokes in blacks can be attributed to hypertension and diabetes.

Left atrial size and the risk of ischemic stroke in an ethnically mixed population

BACKGROUND AND PURPOSE

The association between left atrial size and ischemic stroke is controversial and has been suggested to exist only in men and to be mediated by left ventricular mass. Data are available almost exclusively for white patients. The purpose of this study was to evaluate the association between left atrial size and ischemic stroke in a multiethnic population.

METHODS

A population-based case-control study was conducted in 352 patients aged >39 years with first ischemic stroke and in 369 age-, gender-, and race-ethnicity-matched community controls. Left atrial diameter was measured by 2-dimensional transthoracic echocardiography and indexed by body surface area. Conditional logistic regression analysis was performed to assess the risk of stroke associated with left atrial index in the overall group and in the age, gender, and race-ethnic strata after adjustment for the presence of other stroke risk factors.

RESULTS

Left atrial index was associated with ischemic stroke in the overall group (adjusted OR 1.47 per 10 mm/1.7 m(2) of body surface area; 95% CI 1.03 to 2.11). The association was present in men (adjusted OR 2.81, 95% CI 1.42 to 5.57) but not in women (adjusted OR 1.08, 95% CI 0.70 to 1.66), and in patients aged <60 years (adjusted OR 3.78, 95% CI 1.36 to 10.54) but not >60 years (adjusted OR 1.23, 95% CI 0.84 to 1.81). Subgroup analyses showed the risk to be present in men across all age subgroups. In women, the lack of association between left atrial index and stroke was most strongly influenced by left ventricular hypertrophy. A trend toward an association between left atrial index and stroke was observed in whites (adjusted OR 1.81, 95% CI 0.81 to 4.09) and Hispanics (adjusted OR 1.61, 95% CI 0.98 to 2.65) but was less evident in blacks (adjusted OR 1.25, 95% CI 0.74 to 2.14).

CONCLUSIONS

Left atrial enlargement is associated with an increased risk of ischemic stroke after adjustment for other stroke risk factors, including left ventricular hypertrophy. The association is observed in men of all ages, whereas in women it is attenuated by other factors, especially left ventricular hypertrophy. Interracial differences in the stroke risk may exist that need further investigation.

Stroke in Hispanic veterans: a descriptive study

BACKGROUND

Differences in risk factor prevalence and distribution of atherosclerotic cerebrovascular disease have been reported among different racial-ethnic groups. Identification of stroke syndromes and risk factors specific to the Puerto Rican male population should lead to more effective diagnosis, treatment, and prevention programs.

METHODS

We prospectively and consecutively evaluated 118 Hispanic male veterans admitted to our Stroke Unit from June 1994 to September 1995.

RESULTS

Ninety patients (76%) had an ischemic infarct, 26 (22%) had a transient ischemic attack, and 2 (2%) had an intracerebral and/or subarachnoid hemorrhage. Hypertension was the most common risk factor. Echocardiographic studies were done in 64% of the patients, and the most common findings were concentric left ventricular hypertrophy and diastolic dysfunction. Cerebral angiography was done in 40 cases, and findings were abnormal in 32 (80%).

CONCLUSIONS

We believe this is the largest descriptive study of Hispanic male veterans with stroke syndromes. It provides baseline data to serve as a comparison group for future research.

Differences in stroke between white, Hispanic, and Native American patients: the Barrow Neurological Institute stroke database

BACKGROUND AND PURPOSE

Identification of specific features of stroke in minority populations should lead to more effectively focused treatment and prevention.

METHODS

We examined 1290 white (WHI), 242 Hispanic (HIS), 83 Native American (NA), and 101 other stroke and transient ischemic attack (TIA) patients hospitalized at the Barrow Neurological Institute from 1990 through 1996.

RESULTS

Chi-square analysis detected significant (P<.05) differences as follows: (1) Stroke types--lacunes more prevalent in NA than WHI and HIS (30% versus 16% and 15%); cardioembolic more prevalent in WHI than HIS (16% versus 9%, NA 14%); hemorrhages more prevalent in HIS than WHI and NA (48% versus 37% and 27%); (2) Risk factors--hypertension more prevalent in HIS than WHI (72% versus 66%; NA 71%); diabetes more prevalent in NA than HIS and WHI (62% versus 36% and 17%); cigarette smoking more prevalent in WHI than HIS and NA (61% versus 46% and 41%); cardiac disease more prevalent in WHI than HIS (34% versus 24%; NA 27%); heavier alcohol intake in NA than HIS than WHI (43% versus 24% versus 17%). There were no significant outcome differences between races for any stroke type. ANOVA detected significantly lower mean age at stroke onset in NA than HIS than WHI (56 versus 61 versus 69 years).

CONCLUSIONS

There are significant differences in prevalence of risk factors and stroke types between WHI, HIS, and NA in our hospital-based population. Although the three races appear to respond to risk factors similarly, Hispanics may be especially susceptible to hemorrhage. Further evaluation of these observations in community-based studies will be important.

Variations in average charges for strokes and TIAs: United States, 1995

The 1995 in-hospital charges for 6,628 group health insured stroke victims averaged $11,010 across the country. This total was over twice the average charge for the 1,584 patients hospitalized with a transient ischemic attack (TIA), $4,940. The Mountain and the neighboring Pacific areas of the country reported the highest charges for a stroke, 24 and 16 percent, respectively, higher than the U.S. average. The charges in the East North Central and East South Central areas were the lowest, each under $9,000 and 20 and 25 percent below the norm, respectively. Between study states, the highest stroke charge was reported in Arizona ($17,590) and the lowest in Ohio ($6,670). Hospital charges comprised 81 percent of the total bill to insurance, averaging $8,940. Physicians' charges averaged $2,070, with those in New York 34 percent above the norm and those in Alabama 30 percent below ($1,450). The New Jersey hospital stays averaged 8.1 days, whereas the stay in Oregon was 5.2 days. The total TIA charge was just under $5,000 across the country. Illinois reported the highest TIA in-hospital charge, $6,160, 25 percent above the U.S. average and almost twice the total in Alabama ($3,170). The hospital charges comprised 87 percent of the total, averaging $4,290. Physicians' charges in Pennsylvania were the highest ($890, 37 percent above the U.S. norm of $650) and those in Alabama the lowest ($450, 31 percent below). The average length of stay was 3.7 days for a TIA, ranging from 5.4 days in New York to 2.3 days in Arizona.

Vascular lesions in Chinese patients with transient ischemic attacks

We studied 96 Chinese patients with TIAs using transcranial Doppler and duplex ultrasonography. We found intracranial stenosis or occlusion in 51% of cases and extracranial disease in 19% of cases. The most common intracranial lesion was stenosis of the terminal internal carotid artery or proximal middle cerebral artery, whereas the most common extracranial lesion was stenosis of the carotid bifurcation.

Association of transient ischemic attack/stroke symptoms assessed by standardized questionnaire and algorithm with cerebrovascular risk factors and carotid artery wall thickness. The ARIC Study, 1987-1989

The baseline examination (1987-1989) for the Atherosclerosis Risk in Communities (ARIC) Study was conducted in 15,792 free-living residents aged 45-64 years in four geographically dispersed US communities. A questionnaire on symptoms of transient ischemic attack (TIA) and stroke was evaluated by computer algorithm for 12,205 of these participants. Data were also collected on lipoprotein levels, hemostasis, hematology, anthropometry, blood pressure, medical history, lifestyle, socioeconomic status, and medication use. Noninvasive high resolution B-mode ultrasonographic imaging was used to determine carotid arterial intimal-medial wall thickness (IMT). The cross-sectional relation between the prevalence of TIA/stroke symptoms and putative risk factors was assessed by logistic regression, controlling for age and community. Odds ratios for TIA/stroke symptoms were significantly elevated (p < or = 0.01) for diabetes mellitus, current smoking, hypertension, lower levels of education, income, and work activity, and higher levels of lipoprotein(a), IMT, hemostasis factor VIII, and von Willebrand factor. However, the relations with education and carotid IMT were not present for black Americans. In whites, the relations of TIA/stroke symptoms to IMT were nonlinear. Only at extreme levels of IMT were symptoms substantially more frequent: For example, men with an IMT greater than 1.17 mm or women with an IMT greater than 0.85 mm had approximately twice the odds of having positive TIA/stroke symptoms as those with lower IMTs. The authors plan in future analyses to address the issue prospectively, as well as to examine the relation with magnetic resonance imaging-defined outcomes and clinically defined incident stroke.

Impact of race and ethnicity on ischemic stroke. The University of California at San Diego Stroke Data Bank

BACKGROUND AND PURPOSE

As the US minority population continues to grow, increasing numbers of nonwhite citizens are at risk for stroke. A better understanding of how ischemic stroke differs in the minority populations may lead to more effective clinical management.

METHODS

We prospectively evaluated 542 consecutive patients (416 whites, 71 Mexican Americans, 55 blacks) presenting to the University of California at San Diego Medical Center or the San Diego Veterans Affairs Hospital with presumed acute ischemic stroke or transient ischemic attack.

RESULTS

Whites had a higher proportion of transient ischemic attacks (32% versus 18% and 17% for blacks and Mexican Americans, respectively) and had the lowest prevalence of diabetes mellitus (17% versus 29% and 40% for blacks and Mexican Americans, respectively). Mexican Americans had higher initial serum glucose levels (178 versus 133 and 131 mg/dL for whites and blacks, respectively). Blacks were youngest (average age, 56 years). There were no differences among the groups in the prevalence of prior stroke, hypertension, myocardial infarction, or smoking; initial systolic blood pressure, serum cholesterol levels, and functional deficit also were similar. Although it did not reach statistical significance, there was a trend toward relatively late presentation in the black stroke subpopulation: only 53% of blacks (compared with 73% of both Mexican Americans and whites) reached medical attention within 24 hours of stroke onset. All groups had similar diagnostic evaluations and functional outcome at 1 week. With the exception of a higher frequency of stroke of unknown cause in Hispanics, the distributions of stroke etiologies did not differ significantly among the groups.

CONCLUSIONS

These data suggest that there are significant clinical differences in populations with ischemic stroke and transient ischemic attack that are related to race and ethnic origin, but in our population these differences did not include the extent of diagnostic evaluation undertaken or stroke severity.

Lipoprotein(a) as a correlate of stroke and transient ischemic attack prevalence in a biracial cohort: the ARIC Study. Atherosclerosis Risk in Communities

Although both mean lipoprotein(a) [Lp(a)] concentration and national stroke prevalence estimates are consistently higher in American blacks than in whites, no information exists on the relationship of Lp(a) and stroke prevalence in African-Americans. Associations of Lp(a) with stroke or transient ischemic attack (TIA) are addressed in this report for 15,160 participants--4160 blacks and 11,000 whites--in the Atherosclerosis Risk in Communities (ARIC) Study. Lp(a) was measured in ARIC as its total protein component by double-antibody enzyme-linked immunosorbent assay (ELISA) for apo(a) detection. Self-reported stroke/TIA history was assessed as part of a standardized questionnaire, and resulted in age-adjusted stroke/TIA prevalences of 3.0% in blacks (n = 120) and 2.0% in whites (n = 222). Overall, mean Lp(a) protein levels were markedly higher for blacks than for whites (160.5 versus 81.6 micrograms/mL, respectively), and were statistically significantly higher among individuals reporting stroke/TIA history for both races (191.3 versus 159.6 micrograms/mL in blacks; 100.6 versus 81.2 micrograms/mL in whites). Multivariable logistic regression analysis for the association of Lp(a) protein with stroke/TIA status yielded a prevalence odds ratio (OR) (95% confidence intervals) of 1.17 (1.05, 1.30) overall (based on one standard deviation difference, 108.2 micrograms/mL, in Lp[a] protein). Race-specific ORs, after adjustment for the same covariates, were equivalent for blacks [OR = 1.17 (0.99, 1.39)] and whites [OR = 1.19 (1.04, 1.36)]. These data suggest that Lp(a) is an independent risk factor for stroke/TIA in both blacks and whites, and that the relative risk of stroke/TIA associated with Lp(a) protein does not vary by race.(ABSTRACT TRUNCATED AT 250 WORDS)

Increase in extracranial atherosclerotic carotid lesions in patients with brain ischemia in Japan. An angiographic study

BACKGROUND AND PURPOSE

Atherosclerotic lesions in the cerebral arteries are distributed heterogeneously among different races. Intracranial carotid lesions are reported to be more common than extracranial carotid lesions among Japanese people, which is in sharp contrast to the pattern of cerebral atherosclerosis in whites. However, several Japanese clinicians have the impression, which has yet to be clinically proven, that extracranial carotid diseases are recently increasing in number.

METHODS

One hundred twenty-one patients who developed ischemic stroke and underwent angiography were examined in the study. Seventy were admitted to our clinic from 1963 to 1965 (early group); the remaining 51 patients were seen from 1989 to 1993 (recent group). Angiographic findings and vascular risk factors were compared between the two groups.

RESULTS

Severe atherosclerotic lesions of the extracranial internal carotid arteries increased significantly during the ensuing 24 years between the end of the first period until the beginning of the second period (from 1965 to 1989), whereas lesions in the intracranial carotid system were similar between the two groups. Severe atherosclerosis in the extracranial internal carotid artery was more frequent in patients with diabetes mellitus, which proved to be the only risk factor that showed a temporal increase.

CONCLUSIONS

The proportion of severe atherosclerosis in Japanese patients with brain ischemia has been increasing in the extracranial internal carotid artery, while that in the intracranial carotid system remains unchanged. Such a temporal change may be the result, at least in part, of an increase in the prevalence of diabetes mellitus.

Racial variations in the rates of carotid angiography and endarterectomy in patients with stroke and transient ischemic attack

BACKGROUND

Carotid endarterectomy is emerging as the treatment of choice for patients with symptomatic carotid artery stenosis at low operative risk. We sought to determine if racial variations in the rate of carotid angiography and endarterectomy exist in the Veteran Affairs health care system among patients who are insulated from the cost of their care.

METHODS

From a national database of all hospitalizations at Veterans Affairs medical centers, we identified a cohort of patients with diagnoses of stroke or transient ischemic attack who were likely to be candidates for carotid angiography and endarterectomy. We used logistic regression to determine if the patient's race was associated with receiving carotid angiography and endarterectomy, after adjusting for patient's age, degree of eligibility for Veterans Affairs care, socioeconomic status, comorbidities associated with hospital admission, and geographic region of the hospital.

RESULTS

Of the 35 922 veterans in the cohort, 3535 (9.8%) underwent angiography during the study period and 1249 (3.5%) had carotid endarterectomy. Blacks constituted 18.2% of the patients with a history of stroke or transient ischemic attack, 9.8% of the patients having angiography, but only 4.2% of the patients undergoing carotid endarterectomy. Whites constituted 77.1% of the patients with a history of stroke or transient ischemic attack, 86.1% of the patients receiving angiography, and 93.0% of those having carotid endarterectomies. After adjusting for confounding variables, black patients continued to have a significantly lower likelihood than white patients of undergoing angiography (risk ratio = 0.47; 95% confidence interval = 0.42, 0.53) and subsequent endarterectomy (risk ratio = 0.28; 95% confidence interval = 0.20, 0.38).

CONCLUSIONS

Socioeconomic status and access to care within a large managed health care system do not fully explain racial differences in the rate of carotid angiography and endarterectomy. Either referral bias for evaluation for carotid endarterectomy or racial differences in the extent and location of cerebrovascular disease are more important explanations for the observed racial variations.

Clinical characteristics of transient ischemic attacks in black patients

We analyzed the clinical, CT, and angiographic findings in 50 black patients with carotid transient ischemic attacks (TIAs). Thirty-two percent had TIAs lasting less than 1 hour, 26% had TIAs lasting 1 to 6 hours, and 42% had TIAs lasting 6 to 24 hours. Fifty-two percent of TIA patients had CT evidence of cerebral infarction despite complete clinical recovery. CT was abnormal in two of 16 (13%) patients with TIAs lasting less than 1 hour; however, CT was abnormal in 24 of 34 (70%) patients with TIAs lasting longer than 1 hour. Angiographic findings of extracranial carotid disease appropriate to TIA symptoms were present in 12 (24%) patients. Two patients in whom the TIA episode lasted less than 1 hour later had clinical cerebral infarction, whereas 20 patients with longer-duration TIAs developed ischemic stroke within 4 months. Of these black TIA patients, 22 (44%) developed clinical cerebral infarction.

Ethnic distribution of intracranial aneurysms

The reported higher incidences of intracranial arterial aneurysms (IAA) in Africa and Asia raised the question of possible racial differences in aneurysm incidence. This prompted a retrospective study of the 244 cases of IAA seen at the Henry Ford Hospital (HFH) from 1979 to 1985. There were 171 whites and 73 blacks in the study group. The results showed a higher white to black case ratio (2.3:1) than the white to black hospital population ratio (1.14:1). If only bleeding aneurysms were considered, there were 81 whites and 52 blacks, with a white to black case ratio of 1.6:1, thus giving only a borderline racial difference. The peak age of aneurysm incidence was the fifth decade for blacks and the sixth decade for whites. The most common aneurysms sites were: [table: see text]

Duplex Doppler and spectral flow analysis of racial differences in cerebrovascular atherosclerosis

We compared carotid artery disease in 99 black and 106 white patients using duplex ultrasonography (B-mode imaging and Doppler spectral analysis). Blacks had significantly less stenosis of the extracranial internal carotid artery than whites. Among the risk factors investigated, hypertension alone, ischemic heart disease, diabetes mellitus, and smoking failed to explain the racial difference. Although carotid stenosis of greater than or equal to 40% correlated significantly with age in both races (p = 0.001 in whites and p = 0.005 in blacks), blacks had significantly less carotid stenosis of any degree even when age was taken into account. Multivariate analysis showed that race is a significant and independent risk factor for carotid stenosis (p less than 0.0001). Hypertension interacting with race was also significant. Our results require verification in population-based studies. Carotid duplex ultrasonography offers a noninvasive method for carrying out such studies.