Optimal Angiographic Goal and Number of Passes for Octogenarians Undergoing Endovascular Stroke Thrombectomy.

BACKGROUND: The optimal recanalization goal and number of endovascular thrombectomy (EVT) passes for elderly patients with large vessel occlusion strokes is unclear. METHODS: Consecutive patients 80 years or older undergoing EVT were identified from 2016 to 2022 at a single center. Clinical information, procedural details, and modified treatment in cerebral ischemia (mTICI) scores were collected. Primary outcome was modified Rankin scale (mRS) at 90 days. Bivariate and multivariable analyses were conducted to assess associations between mTICI scores, EVT passes, and 90-day outcomes. RESULTS: One hundred twenty-six patients were identified. At 90 days, mTICI 2b recanalization resulted in high rates of poor outcomes (8.7% functional independence and 60.9% mortality) not significantly different from mTICI 0, 1 or 2a (median mRS 6 vs. 6, P = 0.61). Complete recanalization (mTICI 2c or 3) led to significantly better mRS outcomes at 90 days compared to mTICI 2b (median mRS 4 vs. 6, adjusted P = 0.038), with 26.8% functional independence and 37.8% mortality. In multivariable analysis, complete recanalization was significantly associated with better 90-day outcomes than mTICI 2b or lower recanalization (odds ratio 4.24 [95% Confidence interval 1.46-12.3]; P = 0.002), while the number of passes was not independently associated with worse outcomes (P = 0.98). CONCLUSIONS: For octogenarians, mTICI 2b recanalization yields limited clinical benefit and results in poor 90-day outcomes. In contrast, complete recanalization is independently associated with significantly better outcomes. Thus, once the decision is made to pursue EVT in the elderly, mTICI 2c or better recanalization should be the angiographic goal. Providers should not withhold thrombectomy passes based on age alone.

The BAND score: A simple model for upfront prediction of poor outcomes despite successful stroke thrombectomy.

BACKGROUND: While endovascular thrombectomy (EVT) is beneficial for patients with acute large vessel occlusion ischemic strokes, a significant portion of patients still do poorly despite successful recanalization. Identifying patients at high risk for poor outcomes can be helpful for future clinical trial design and optimizing acute stroke triage. METHODS: Consecutive EVT patients were identified from 2016 to 2021 at a Comprehensive Stroke Center, and clinical information was recorded. Poor outcome was defined as a 90-day modified Rankin Scale (mRS) of 4 or greater despite achieving a modified thrombolysis in cerebral infarction (mTICI) score of 2b or greater. Multivariable regression analyses were used to identify risk factors for poor outcomes, and a scoring system was constructed. RESULTS: 483 patients with successful recanalization were identified. From a randomly selected training cohort (n = 357), the 10-point BAND score was constructed from independent risk factors for poor outcomes: baseline disability (1 point: baseline mRS ≥ 2), age (1 point: 60-69 years, 2 points: 70-79 years, 3 points: 80-84 years, 4 points: 85 years or older), NIHSS (2 points: 13-17, 3 points: 18-22, and 4 points: ≥ 23), and delay from last known normal (1 point: ≥ 6 h). The BAND score was significantly associated with rates of poor outcomes (p < 0.001), and it achieved an area under the receiver-operating characteristic curve (AUC) of 0.80 (95 %CI 0.76-0.85) in our training cohort and 0.78 (95 %CI 0.70-0.86) in our validation cohort (n = 126). Overall, the BAND score had a significantly higher AUC value than the widely validated THRIVE score and the THRIVE-EVT calculation (p = 0.001 and 0.029, respectively). Among patients with high BAND scores (7 or higher), 88.2 % had poor outcomes. CONCLUSION: The BAND score is a simple tool to predict poor outcomes despite successful recanalization. Future studies are needed to confirm the BAND score's external validity.

Peri-procedural decrease in hemoglobin following mechanical thrombectomy for ischemic stroke.

BACKGROUND: Peri-procedural blood loss and hemodilution occur in patients undergoing mechanical thrombectomy (MT) for ischemic stroke; however, its relationships with thrombectomy passes, procedure times, and clinical outcomes are unknown. METHODS: Consecutive patients undergoing MT for anterior circulation large-vessel occlusion ischemic strokes were identified at a Comprehensive Stroke Center. Clinical information, modified treatment in cerebral ischemia (mTICI) scores, and modified Rankin Scores (mRS) at 90 days were prospectively collected from 2012 to 2021. Hemoglobin measurements before and after MTs were collected retrospectively via chart review, and changes were quantified. Patients with new-onset severe anemia (defined as post-MT hemoglobin less than 10g/dL) were identified. Modified Rankin scale (mRS) at 90 days was used to measure clinical outcomes. RESULTS: Four-hundred and forty-five patients were identified. Hemoglobin decreased 1.27 ± 1.05 g/dL after MT on average. Greater number of thrombectomy passes and longer procedure times were associated with larger decreases in hemoglobin (p < 0.001 and p = 0.002, respectively). 11.5% (51 of 445) of patients had new-onset severe anemia, and this incidence was significantly higher with more thrombectomy passes (6.4% for one pass, 11.9% for two passes, and 17.4% for three or more passes; p = 0.010). In multivariable analyses, new-onset severe anemia was associated with significantly higher odds of 90-day poor outcomes (mRS 3-6, OR 2.70 [95%CI 1.12-6.51], p = 0.027) and death (OR 2.73 [95%CI 1.06-7.04], p = 0.037) compared to mild post-MT anemia. CONCLUSIONS: More thrombectomy passes and longer procedure times were significantly associated with larger peri-procedural decreases in hemoglobin. Patients with new-onset hemoglobin less than 10 g/dL are at risk of poor outcomes.

Black-white Differences in Left Ventricular Hypertrophy Rates Among Young Adults with Ischemic Stroke.

OBJECTIVES: Few studies have addressed Black-White differences in left ventricular hypertrophy (LVH) in young stroke patients without a history of hypertension. METHODS: A case-only cross-sectional analysis performed in 2019 of data from the Stroke Prevention in Young Adults Study, a population-based case-control study of ischemic stroke patients ages 15-49. The main outcomes were hypertension indicators at the time of stroke hospitalization: self-reported history of hypertension, LVH by echocardiography (Echo-LVH) and LVH by electrocardiogram (ECG-LVH). The prevalence of Echo-LVH was further determined in those with and without a history of hypertension. Adjusted odds ratios and 95% confidence intervals comparing blacks and whites were calculated by logistic regression. RESULTS: The study population included 1028 early-onset ischemic stroke patients, 48% Black cases, 54% men, median age 43 years (interquartile range, 38-46 years). Overall, the prevalence of hypertension history, Echo-LVH and ECG-LVH were 41.3%, 34.1% and 17.5%, respectively. Each of the hypertension indicators were more frequent in men than in women and in Black cases than in White cases. Black patients without a history of hypertension had higher rates of Echo-LVH than their white counterparts, 40.3% vs 27.7% (age and obesity adjusted OR 1.8; 95% CI 1.02-3.4) among men and 20.9% vs 7.6% (adjusted OR 2.7; 95% CI 1.2-6.2) among women. CONCLUSIONS: LVH was common in young patients with ischemic stroke, regardless of self-reported history of hypertension. These findings emphasize the need for earlier screening and more effective treatment of hypertension in young adults, particularly in the Black population.

Black-White Differences in Ischemic Stroke Risk Factor Burden in Young Adults.

BACKGROUND AND PURPOSE: Although the US Black population has a higher incidence of stroke compared with the US White population, few studies have addressed Black-White differences in the contribution of vascular risk factors to the population burden of ischemic stroke in young adults. METHODS: A population-based case-control study of early-onset ischemic stroke, ages 15 to 49 years, was conducted in the Baltimore-Washington DC region between 1992 and 2007. Risk factor data was obtained by in-person interview in both cases and controls. The prevalence, odds ratio, and population-attributable risk percent (PAR%) of smoking, diabetes, and hypertension was determined among Black patients and White patients, stratified by sex. RESULTS: The study included 1044 cases and 1099 controls. Of the cases, 47% were Black patients, 54% were men, and the mean (±SD) age was 41.0 (±6.8) years. For smoking, the population-attributable risk percent were White men 19.7%, White women 32.5%, Black men 10.1%, and Black women 23.8%. For diabetes, the population-attributable risk percent were White men 10.5%, White women 7.4%, Black men 17.2%, and Black women 13.4%. For hypertension, the population-attributable risk percent were White men 17.2%, White women 19.3%, Black men 45.8%, and Black women 26.4%. CONCLUSIONS: Modifiable vascular risk factors account for a large proportion of ischemic stroke in young adults. Cigarette smoking was the strongest contributor to stroke among White patients while hypertension was the strongest contributor to stroke among Black patients. These results support early primary prevention efforts focused on smoking cessation and hypertension detection and treatment.

Telestroke Across the Continuum of Care: Lessons from the COVID-19 Pandemic.

While use of telemedicine to guide emergent treatment of ischemic stroke is well established, the COVID-19 pandemic motivated the rapid expansion of care via telemedicine to provide consistent care while reducing patient and provider exposure and preserving personal protective equipment. Temporary changes in re-imbursement, inclusion of home office and patient home environments, and increased access to telehealth technologies by patients, health care staff and health care facilities were key to provide an environment for creative and consistent high-quality stroke care. The continuum of care via telestroke has broadened to include prehospital, inter-facility and intra-facility hospital-based services, stroke telerehabilitation, and ambulatory telestroke. However, disparities in technology access remain a challenge. Preservation of reimbursement and the reduction of regulatory burden that was initiated during the public health emergency will be necessary to maintain expanded patient access to the full complement of telestroke services. Here we outline many of these initiatives and discuss potential opportunities for optimal use of technology in stroke care through and beyond the pandemic.

Sickle Cell Trait and Risk of Ischemic Stroke in Young Adults.

BACKGROUND AND PURPOSE: Approximately 8% of Blacks have sickle cell trait (SCT), and there are conflicting reports from recent cohort studies on the association of SCT with ischemic stroke (IS). Most prior studies focused on older populations, with few data available in young adults. METHODS: A population-based case-control study of early-onset IS was conducted in the Baltimore-Washington region between 1992 and 2007. From this study, 342 Black IS cases, ages 15 to 49, and 333 controls without IS were used to examine the association between SCT and IS. Each participant's SCT status was established by genotyping and imputation. For analysis, χ2 tests and logistic regression models were performed with adjustment for potential confounding variables. RESULTS: Participants with SCT (n=55) did not differ from those without SCT (n=620) in prevalence of hypertension, previous myocardial infarction, diabetes mellitus, and current smoking status. Stroke cases had increased prevalence in these risk factors compared with controls. We did not find an association between SCT and early-onset IS in our overall population (odds ratio=0.9 [95% CI, 0.5-1.7]) or stratified by sex in males (odds ratio=1.26 [95% CI, 0.56-2.80]) and females (odds ratio=0.67 [95% CI, 0.28-1.69]). CONCLUSIONS: Our data did not find evidence of increased risk of early-onset stroke with SCT.

Smoking and Risk of Ischemic Stroke in Young Men.

BACKGROUND AND PURPOSE: There is a strong dose-response relationship between smoking and risk of ischemic stroke in young women, but there are few data examining this association in young men. We examined the dose-response relationship between the quantity of cigarettes smoked and the odds of developing an ischemic stroke in men under age 50 years. METHODS: The Stroke Prevention in Young Men Study is a population-based case-control study of risk factors for ischemic stroke in men ages 15 to 49 years. The χ2 test was used to test categorical comparisons. Logistic regression models were used to calculate the odds ratio for ischemic stroke occurrence comparing current and former smokers to never smokers. In the first model, we adjusted solely for age. In the second model, we adjusted for potential confounding factors, including age, race, education, hypertension, myocardial infarction, angina, diabetes mellitus, and body mass index. RESULTS: The study population consisted of 615 cases and 530 controls. The odds ratio for the current smoking group compared with never smokers was 1.88. Furthermore, when the current smoking group was stratified by number of cigarettes smoked, there was a dose-response relationship for the odds ratio, ranging from 1.46 for those smoking <11 cigarettes per day to 5.66 for those smoking 40+ cigarettes per day. CONCLUSIONS: We found a strong dose-response relationship between the number of cigarettes smoked daily and ischemic stroke among young men. Although complete smoking cessation is the goal, even smoking fewer cigarettes may reduce the risk of ischemic stroke in young men.

Cocaine Use and Risk of Ischemic Stroke in Young Adults.

BACKGROUND AND PURPOSE: Although case reports have long identified a temporal association between cocaine use and ischemic stroke (IS), few epidemiological studies have examined the association of cocaine use with IS in young adults, by timing, route, and frequency of use. METHODS: A population-based case-control study design with 1090 cases and 1154 controls was used to investigate the relationship of cocaine use and young-onset IS. Stroke cases were between the ages of 15 and 49 years. Logistic regression analysis was used to evaluate the association between cocaine use and IS with and without adjustment for potential confounders. RESULTS: Ever use of cocaine was not associated with stroke with 28% of cases and 26% of controls reporting ever use. In contrast, acute cocaine use in the previous 24 hours was strongly associated with increased risk of stroke (age-sex-race adjusted odds ratio, 6.4; 95% confidence interval, 2.2-18.6). Among acute users, the smoking route had an adjusted odds ratio of 7.9 (95% confidence interval, 1.8-35.0), whereas the inhalation route had an adjusted odds ratio of 3.5 (95% confidence interval, 0.7-16.9). After additional adjustment for current alcohol, smoking use, and hypertension, the odds ratio for acute cocaine use by any route was 5.7 (95% confidence interval, 1.7-19.7). Of the 26 patients with cocaine use within 24 hours of their stroke, 14 reported use within 6 hours of their event. CONCLUSIONS: Our data are consistent with a causal association between acute cocaine use and risk of early-onset IS.

Progressive Wallerian Degeneration of the Corpus Callosal Splenium in a Patient with Alexia Without Agraphia: Advanced MR Findings.

The corpus callosal splenium is an uncommon location for Wallerian degeneration (WD), which may be mistaken for new pathology on magnetic resonance imaging (MRI). We describe the case of a 69-year-old woman with a left posterior cerebral artery infarct in whom progressive WD of the splenium of the corpus callosum seen on MRI was misinterpreted as new infarction or neoplasm. We address how magnetic resonance spectroscopy, perfusion MRI, diffusion tensor MRI, and serial imaging were utilized in establishing the correct diagnosis. Interestingly, the patient also presented with alexia without agraphia, which has never been reported in association with splenial WD. It is conceivable that WD affected critical splenial association fibers resulting in this uncommon dissociation syndrome.

Prothrombin G20210A mutation is associated with young-onset stroke: the genetics of early-onset stroke study and meta-analysis.

BACKGROUND AND PURPOSE: Although the prothrombin G20210A mutation has been implicated as a risk factor for venous thrombosis, its role in arterial ischemic stroke is unclear, particularly among young adults. To address this issue, we examined the association between prothrombin G20210A and ischemic stroke in a white case-control population and additionally performed a meta-analysis. METHODS: From the population-based Genetics of Early Onset Stroke (GEOS) study, we identified 397 individuals of European ancestry aged 15 to 49 years with first-ever ischemic stroke and 426 matched controls. Logistic regression was used to calculate odds ratios (ORs) in the entire population and for subgroups stratified by sex, age, oral contraceptive use, migraine, and smoking status. A meta-analysis of 17 case-control studies (n=2305 cases <55 years) was also performed with and without GEOS data. RESULTS: Within GEOS, the association of the prothrombin G20210A mutation with ischemic stroke did not achieve statistical significance (OR=2.5; 95% confidence interval [CI]=0.9-6.5; P=0.07). However, among adults aged 15 to 42 years (younger than median age), cases were significantly more likely than controls to have the mutation (OR=5.9; 95% CI=1.2-28.1; P=0.03), whereas adults aged 42 to 49 years were not (OR=1.4; 95% CI=0.4-5.1; P=0.94). In our meta-analysis, the mutation was associated with significantly increased stroke risk in adults ≤55 years (OR=1.4; 95% CI=1.1-1.9; P=0.02), with significance increasing with addition of the GEOS results (OR=1.5; 95% CI=1.1-2.0; P=0.005). CONCLUSIONS: The prothrombin G20210A mutation is associated with ischemic stroke in young adults and may have an even stronger association among those with earlier onset strokes. Our finding of a stronger association in the younger young adult population requires replication.

Polymorphisms in migraine-associated gene, atp1a2, and ischemic stroke risk in a biracial population: the genetics of early onset stroke study.

In a recent meta-analysis migraine was associated with a two-fold increase in stroke risk. While the mechanism driving this association is unknown, one intriguing hypothesis is that migraineurs are genetically predisposed to developing ischemic stroke. Mutations in the ATP1A2 gene are implicated in familial hemiplegic migraine type II and increase the severity of ischemic brain injury in animal models. To further explore these observations, we assessed the association between ATP1A2 polymorphisms, migraine, and the risk of ischemic stroke in participants of the Genetics of Early-Onset Stroke Study, a population-based case-control study of ischemic stroke among men and women aged 15-49. Using responses to a headache symptoms questionnaire, subjects were classified as having no migraine, or migraine with or without visual aura. Evaluating a total of 134 ATP1A2 polymorphisms genotyped using a combination of Illumina platforms (Cardiovascular Gene-centric 50 K SNP Array and HumanOmni1-Quad_v1-0_B Bead Chip), only one polymorphism (rs2070704) demonstrated a nominally significant association with stroke in an age-, gender-, ethnicity-adjusted model (OR = 0.83, 95% CI = 0.71-0.98, p = 0.025) and in a vascular risk factor model adjusting for age, gender, ethnicity, hypertension, diabetes, smoking, and myocardial infarction (OR = 0.74, 95% CI = 0.63-0.89, p = 0.001). Ethnicity-stratified analyses demonstrated a significant association for rs2070704 among African-Americans (OR = 0.68, 95% CI = 0.53-0.90, p = 0.005) but not Caucasians (OR = 0.82, 95% CI = 0.64-1.04, p = 0.107). These associations were unchanged when migraine subtypes were included as co-variates. We did not observe an association between ATP1A2 polymorphisms and migraine. While our results do not demonstrate a strong relationship between ATP1A2 polymorphisms and migraine associated stroke risk, the results are hypothesis generating and indicate that an association between ATP1A2 polymorphisms and stroke risk may exist. Additional studies are required.

Factor V leiden and ischemic stroke risk: the Genetics of Early Onset Stroke (GEOS) study.

BACKGROUND: Factor V Leiden (FVL) has been associated with ischemic stroke in children but not in adults. Although the FVL mutation is associated with increased risk for venous thrombosis, its association with ischemic stroke in young adults remains uncertain. Therefore, we examined the association between FVL and ischemic stroke in participants of the Genetics of Early Onset Stroke (GEOS) study. METHODS: A population-based case control study identified 354 women and 476 men 15 to 49 years of age with first-ever ischemic stroke and 907 controls. Participant-specific data included vascular risk factors, FVL genotype and, for cases, the ischemic stroke subtype by modified Trial of ORG 10172 in Acute Stroke criteria. Logistic regression was used to calculate odds ratios for the entire population and for subgroups stratified by risk factors and ischemic stroke subtype. RESULTS: The frequency of the FVL mutation was similar between ischemic stroke patients (3.6%; 95% confidence interval [CI] 2.5%-5.1%) and nonstroke controls (3.8%; 95% CI 2.7%-5.2%). This frequency did not change significantly when cases were restricted to patients with stroke of undetermined etiology (4.1%; 95% CI 2.6%-6.4%). CONCLUSIONS: Among young adults, we found no evidence for an association between FVL and either all ischemic stroke or the subgroup with stroke of undetermined etiology.

Rare variants in ischemic stroke: an exome pilot study.

The genetic architecture of ischemic stroke is complex and is likely to include rare or low frequency variants with high penetrance and large effect sizes. Such variants are likely to provide important insights into disease pathogenesis compared to common variants with small effect sizes. Because a significant portion of human functional variation may derive from the protein-coding portion of genes we undertook a pilot study to identify variation across the human exome (i.e., the coding exons across the entire human genome) in 10 ischemic stroke cases. Our efforts focused on evaluating the feasibility and identifying the difficulties in this type of research as it applies to ischemic stroke. The cases included 8 African-Americans and 2 Caucasians selected on the basis of similar stroke subtypes and by implementing a case selection algorithm that emphasized the genetic contribution of stroke risk. Following construction of paired-end sequencing libraries, all predicted human exons in each sample were captured and sequenced. Sequencing generated an average of 25.5 million read pairs (75 bp×2) and 3.8 Gbp per sample. After passing quality filters, screening the exomes against dbSNP demonstrated an average of 2839 novel SNPs among African-Americans and 1105 among Caucasians. In an aggregate analysis, 48 genes were identified to have at least one rare variant across all stroke cases. One gene, CSN3, identified by screening our prior GWAS results in conjunction with our exome results, was found to contain an interesting coding polymorphism as well as containing excess rare variation as compared with the other genes evaluated. In conclusion, while rare coding variants may predispose to the risk of ischemic stroke, this fact has yet to be definitively proven. Our study demonstrates the complexities of such research and highlights that while exome data can be obtained, the optimal analytical methods have yet to be determined.

Pearls: stroke.

The diagnosis of ischemic stroke continues to be a clinical one, although advances in neuroimaging have expanded our understanding of the correlation between clinical symptoms and neuroanatomical localization. Careful neurologic examination allows localization in both neuroanatomical and vascular space. Findings on neuroimaging are then correlated to assess their clinical relevance. Transient ischemic attack is recognized as a warning sign for impending vascular disease, but even less specific transient neurologic symptoms are associated with increased risk. Stroke can occur at any age. For women, the postpartum period is a time of elevated risk for arterial ischemic stroke.

Frequency of unrecognized Fabry disease among young European-American and African-American men with first ischemic stroke.

BACKGROUND AND PURPOSE: The cause of initial ischemic stroke in up to 30% of young patients remains unclear. Fabry disease, due to deficient alpha-galactosidase A (alpha-Gal A) activity, is a vascular endothelial glycosphingolipid storage disease typically presenting in childhood. With advancing age, patients develop renal, cardiac, and cerebrovascular disease and die prematurely. A European study suggested an increased prevalence of unrecognized Fabry disease in patients with cryptogenic stroke. We hypothesized that alpha-Gal A deficiency is a rare cause of initial early-onset ischemic stroke in men. METHODS: The Stroke Prevention in Young Men Study enrolled >550 men (15 to 49 years) with first ischemic stroke in the Baltimore-Washington area in 2004 to 2007. Frozen plasma samples were assayed for alpha-Gal A activity, and DNA from patients with consistently low plasma alpha-Gal A activities were sequenced. RESULTS: The study sample consisted of 558 men (42% African-American; median age 44 years). Stroke was cryptogenic in 154 men (40% African-American). In 10 patients with low plasma alpha-Gal A activities, DNA sequencing identified alterations in the alpha-Gal A gene in 2 patients. The polymorphism, D313Y, which results in low plasma enzyme activity, but near normal levels of cellular activity was seen in one European-American male. The Fabry disease-causing A143T mutation was seen in an African-American male with cryptogenic stroke (0.18% of all strokes: upper 95% CI=0.53%; 0.65% of cryptogenic strokes: upper 95% CI=1.92%). CONCLUSIONS: In this biracial population, unrecognized Fabry disease is a rare but treatable cause of initial ischemic stroke in young men.

Evaluation of self-reported ethnicity in a case-control population: the stroke prevention in young women study.

BACKGROUND: Population-based association studies are used to identify common susceptibility variants for complex genetic traits. These studies are susceptible to confounding from unknown population substructure. Here we apply a model-based clustering approach to our case-control study of stroke among young women to examine if self-reported ethnicity can serve as a proxy for genetic ancestry. FINDINGS: A population-based case-control study of stroke among women aged 15-49 identified 361 cases of first ischemic stroke and 401 age-comparable control subjects. Thirty single nucleotide polymorphisms (SNPs) throughout the genome unrelated to stroke risk and with established ancestry-based allele frequency differences were genotyped in all participants. The Structure program was used to iteratively evaluate for K = 1 to 5 potential genetic-based subpopulations. Evaluating the population as a whole, the Structure output plateaued at K = 2 clusters. 98% of self-reported Caucasians had an estimated probability >/=50% of belonging to Cluster 1, while 94% of self-reported African-Americans had an estimated probability >/=50% of belonging to Cluster 2. Stratifying the participants by self-reported ethnicity and repeating the analyses revealed the presence of two clusters among Caucasians, suggesting that potential substructure may exist. CONCLUSIONS: Among our combined sample of African-American and Caucasian participants there is no large unknown subpopulation and self-reported ethnicity can serve as a proxy for genetic ancestry. Ethnicity-specific analyses indicate that population substructure may exist among the Caucasian participants indicating that further studies are warranted.

Relation of candidate genes that encode for endothelial function to migraine and stroke: the Stroke Prevention in Young Women study.

BACKGROUND AND PURPOSE: Migraine with aura is a risk factor for ischemic stroke, but the mechanism by which these disorders are associated remains unclear. Both disorders exhibit familial clustering, which may imply a genetic influence on migraine and stroke risk. Genes encoding for endothelial function are promising candidate genes for migraine and stroke susceptibility because of the importance of endothelial function in regulating vascular tone and cerebral blood flow. METHODS: Using data from the Stroke Prevention in Young Women study, a population-based case-control study including 297 women aged 15 to 49 years with ischemic stroke and 422 women without stroke, we evaluated whether polymorphisms in genes regulating endothelial function, including endothelin-1 (EDN), endothelin receptor type B (EDNRB), and nitric oxide synthase-3 (NOS3), confer susceptibility to migraine and stroke. RESULTS: EDN SNP rs1800542 and rs10478723 were associated with increased stroke susceptibility in whites (OR, 2.1; 95% CI, 1.1-4.2 and OR, 2.2; 95% CI, 1.1-4.4; P=0.02 and 0.02, respectively), as were EDNRB SNP rs4885493 and rs10507875, (OR, 1.7; 95% CI, 1.1-2.7 and OR, 2.4; 95% CI, 1.4-4.3; P=0.01 and 0.002, respectively). Only 1 of the tested SNP (NOS3 rs3918166) was associated with both migraine and stroke. CONCLUSIONS: In our study population, variants in EDN and EDNRB were associated with stroke susceptibility in white but not in black women. We found no evidence that these genes mediate the association between migraine and stroke.

Dose-response relationship between cigarette smoking and risk of ischemic stroke in young women.

BACKGROUND AND PURPOSE: Although cigarette smoking is known to be a risk factor for ischemic stroke, there are few data on the dose-response relationship between smoking and stroke risk in a young ethnically diverse population. METHODS: We used data from the Stroke Prevention in Young Women Study, a population-based case-control study of risk factors for ischemic stroke in women aged 15 to 49 years to examine the relationship between cigarette smoking and ischemic stroke. Historical data, including smoking history, was obtained through standardized interviews. Odds ratios (OR) were estimated using logistic regression. Cases (n=466) were women with stroke in the greater Baltimore-Washington area, and controls (n=604) were women free of a stroke history identified by random digit dialing. RESULTS: After multivariable adjustment, the OR comparing current smokers to never smokers was 2.6 (P<0.0001); no difference in stroke risk was observed between former smokers and never smokers. Adjusted OR increased with increasing number of cigarettes smoked per day (OR=2.2 for 1 to 10 cigs/d; 2.5 for 11 to 20 cigs/d; 4.3 for 21 to 39 cigs/d; 9.1 for 40 or more cigs/d). CONCLUSIONS: These results suggest a strong dose-response relationship between cigarette smoking and ischemic stroke risk in young women and reinforce the need for aggressive smoking cessation efforts in young adults.

Ischemic stroke risk, smoking, and the genetics of inflammation in a biracial population: the stroke prevention in young women study.

BACKGROUND: Although cigarette smoking is a well-established risk factor for vascular disease, the genetic mechanisms that link cigarette smoking to an increased incidence of stroke are not well understood. Genetic variations within the genes of the inflammatory pathways are thought to partially mediate this risk. Here we evaluate the association of several inflammatory gene single nucleotide polymorphisms (SNPs) with ischemic stroke risk among young women, further stratified by current cigarette smoking status. METHODS: A population-based case-control study of stroke among women aged 15-49 identified 224 cases of first ischemic stroke (47.3% African-American) and 211 age-comparable control subjects (43.1% African-American). Several inflammatory candidate gene SNPs chosen through literature review were genotyped in the study population and assessed for association with stroke and interaction with smoking status. RESULTS: Of the 8 SNPs (across 6 genes) analyzed, only IL6 SNP rs2069832 (allele C, African-American frequency = 92%, Caucasian frequency = 55%) was found to be significantly associated with stroke using an additive model, and this was only among African-Americans (age-adjusted: OR = 2.2, 95% CI = 1.0-5.0, p = 0.049; risk factor adjusted: OR = 2.5, 95% CI = 1.0-6.5, p = 0.05). When stratified by smoking status, two SNPs demonstrated statistically significant gene-environment interactions. First, the T allele (frequency = 5%) of IL6 SNP rs2069830 was found to be protective among non-smokers (OR = 0.30, 95% CI = 0.11-.082, p = 0.02), but not among smokers (OR = 1.63, 95% CI = 0.48-5.58, p = 0.43); genotype by smoking interaction (p = 0.036). Second, the C allele (frequency = 39%) of CD14 SNP rs2569190 was found to increase risk among smokers (OR = 2.05, 95% CI = 1.09-3.86, p = 0.03), but not among non-smokers (OR = 0.93, 95% CI = 0.62-1.39, p = 0.72); genotype by smoking interaction (p = 0.039). CONCLUSION: This study demonstrates that inflammatory gene SNPs are associated with early-onset ischemic stroke among African-American women (IL6) and that cigarette smoking may modulate stroke risk through a gene-environment interaction (IL6 and CD14). Our finding replicates a prior study showing an interaction with smoking and the C allele of CD14 SNP rs2569190.