Sex differences in acute ischaemic stroke patients: clinical presentation, causes and outcomes

Sex Differences in Prognosis of Childhood Arterial Ischemic Stroke: Results From Chinese Pediatric Ischemic Stroke Registry Multicenter Registry

BACKGROUND

Current studies on the impact of sex in the prognosis of childhood arterial ischemic stroke (AIS) are limited. We aimed to explore the sex differences in outcomes in patients with childhood AIS.

METHODS

A retrospective analysis was conducted using the prospective data from the Chinese Pediatric Ischemic Stroke Registry. Baseline characteristics between sexes were compared in the total population cohort, propensity score (PS)-matched cohort, and inverse probability of treatment weighting cohort. Multivariate logistic regression and ordinal regression were used to analyze the association of sex with outcomes. Mixed-effects regression model was applied to further analyze the improvement in pediatric modified Rankin Scale (mRS) scores between sexes from 90 days to one year. Survival analysis was used to estimate the recurrence rates during the follow-up period.

RESULTS

A total of 468 patients were finally included. Multivariate logistic regression showed that there were no significant differences between females and males in achieving favorable outcome (odds ratio [OR] 1.04, 95% confidence interval [CI] 0.63 to 1.72), functional independence (OR 0.98, 95% CI 0.59 to 1.63), or shift to worse pediatric mRS scores (OR 0.83, 95% CI 0.59 to 1.17) at 90-day. Mixed-effects regression and survival analysis indicated that females and males exhibited comparable functional recovery from 90 days to one year and had similar recurrent risk during the follow-up period.

CONCLUSIONS

This nationally-representative observational study indicated that both male and female pediatric patients with AIS exhibited comparable similar clinical outcomes at 90 days, as well as similar improvements and risks of recurrence during the follow-up period.

Etiological Subclassification of Stroke in Older People ≥80 Years Compared to Younger People: A Systematic Review and Meta-Analysis

BACKGROUND

Due to the rapid growth of the world´s oldest population, the number of older persons with stroke is expected to rise. Knowledge of stroke etiology is essential to offer personalized and equal health care across age groups. The present systematic review aimed to investigate the prevalence of etiological subtypes of ischemic and hemorrhagic stroke in older compared to younger people.

METHODS

MEDLINE, Embase, Cochrane, Epistemonikos, and Cinahl were systematically searched for studies regarding etiological classification in people ≥80 years compared to those <80 years with ischemic or hemorrhagic stroke.

RESULTS

Out of 28 441 identified articles, eight met the inclusion criteria. In total, 8223 individuals were included in meta-analyses, of whom 2997 were 80 years or older. We demonstrated a higher prevalence of cardioembolic stroke in people ≥80 years OR 1.68 (95% CI, 1.12-2.53). Small vessel disease was significantly less common in older people OR .64 (95% CI, .50-.81). Regarding large vessel disease, no statistically significant difference between the two groups was shown OR 1.05 (95% CI, .77-1.43).

CONCLUSION

In people ≥80 years, cardioembolic stroke is more common, and small vessel disease less common compared to people <80 years. Overall, the results have to be interpreted with caution due to few studies. Large studies using validated classification systems are needed.

Sex disparity in stroke outcomes in a multicenter prospective stroke registry in Vietnam

BACKGROUND

Although men have a higher rate of stroke than women, it is not clear whether women have a worse outcome after adjusting for confounders such as vascular risk factors, age, stroke severity, and reperfusion therapy. We evaluated sex differences on 90-day functional outcomes after stroke in a multicenter study in Vietnam.

METHODS

We recruited patients presenting with ischemic or hemorrhagic stroke at 10 stroke centers in Vietnam for a period of 1 month from 1 August 2022 to 31 August 2022. We reviewed the patient's clinical demographics, time from symptom onset to hospital admission, stroke classification, stroke subtype, stroke severity, characteristics of reperfusion therapy, and 90-day clinical outcome. We compared functional outcomes and predisposing factors at day 90 between men and women after an ischemic and hemorrhagic stroke. Poor outcome was defined as modified Rankin Scale 3-6.

RESULTS

There were 2300 stroke patients included. Men accounted for 61.3% (1410) of participants. Compared to men, women were older (67.7 ± 13.9 vs 63.7 ± 13.3, P < 0.001), had a higher rate of diabetes mellitus (21.1% vs 15.3%, P < 0.001), a lower rate of tobacco use (1.0 % vs 23.6%, P < 0.001), and a lower body mass index (21.4 ± 2.70 vs 22.0 ± 2.72, P < 0.001). There was a higher rate of intracranial hemorrhage (ICH) in men (21.3% vs 15.6%, P = 0.001), whereas the rate of subarachnoid hemorrhage was higher in women (6.2% vs 3.0%, P < 0.001). For ischemic stroke, door-to-needle time (36.9 ± 17.6 vs 47.8 ± 35.2 min, P = 0.04) and door-to-recanalization time (113.6 ± 51.1 vs 134.2 ± 48.2, P = 0.03) were shorter in women. There was no difference in 90-day functional outcomes between sexes. Factors associated with poor outcomes included age ⩾50 years (adjusted odds ratio (aOR): 1.75; 95% confidence interval (CI): 1.16-2.66), history of stroke (aOR: 1.50; 95% CI: 1.15-1.96), large artery atherosclerosis (aOR: 5.19; 95% CI: 3.90-6.90), and cardioembolism (aOR: 3.21; 95% CI: 1.68-6.16). Factors associated with mortality in patients with acute ischemic stroke included a history of coronary artery disease (aOR: 3.04; 95% CI: 1.03-8.92), large artery atherosclerosis (aOR: 3.37; 95% CI: 2.11-5.37), and cardioembolism (aOR: 3.15; 95% CI: 1.20-8.27).

CONCLUSION

There were no sex differences in the clinical outcome of stroke and ischemic stroke in this prospective cohort of hospitalized Vietnamese patients.

Sex Differences in Neurological Emergencies Presenting to Multiple Urban Level 1 Trauma Centers

Previous studies have suggested that there are sex differences in the treatment and outcome of neurological emergencies; however, research identifying the role these sex differences play in the management of neurological emergencies is lacking. More knowledge of the way sex factors into the pathophysiology of neurological emergencies will be helpful in improving outcomes for these patients. The aim of this cross-sectional study was to assess the prevalence and management of neurological emergencies while evaluating sex differences in the diagnosis and treatment of these emergencies. We analyzed a cohort of 530 adult patients from four level 1 trauma centers over a period of 4 weeks who had a chief complaint of a neurological emergency, including seizures, cerebrovascular events, headache disorders, traumatic brain injuries, and central nervous system infections. Among patients with neurological emergencies, a significantly lower proportion of female patients underwent neurosurgery and were admitted to the intensive care unit compared to male patients, but there were no significant differences between sexes in the time of symptom onset, type of hospital transportation, amount of neuroimaging performed, admission rates, hospital length of stay, and disposition from the emergency department. Although female patients were more likely to have a chief complaint of headache compared to traumatic injuries in male patients, this was not statistically significant. A significantly higher proportion of female patients had health insurance coverage than male patients.

Factors influencing recurrence after an ischemic stroke vary by sex

OBJECTIVES

To determine the factors that affect recurrent stroke after acute ischemic stroke, specifically between male and female groups.

METHODS

We examined relative factors associated with recurrent stroke in Chinese patients with first-ever ischemic stroke. LASSO (least absolute shrinkage and selection operator) Cox regression were used to determine the predictors of recurrent stroke in the male and female groups. Next, We used Kaplan-Meier survival curves and interactions among these predictors to assess the association between relapse-related factors and recurrent stroke.

RESULTS

During one year of follow-up, we documented 42 incidents of recurrent stroke in males and 15 in females. There was no significant difference in the overall recurrence rate between men and women. We finally identified three variables in males and one variable in females associated considerably with recurrent stroke by LASSO Cox regression. In females, good sleep appeared to be the most significant protective factor against recurrent stroke(hazard ratio [HR], 0.21; 95% CI, 0.08-0.57). In the male group, we found two risk factors: atherosclerotic burden (HR, 2.42; 95% CI, 1.30-4.51) and coronary heart disease (HR, 2.98; 95% CI, 1.16-7.66); and one protective factor: domestic/physical activities (HR, 0.45; 95% CI, 0.24-0.83). We also found an interaction between good sleep and domestic/physical activities in males (Pinteraction = 0.016).

DISCUSSION

Our data indicate that the factors for recurrent stroke may differ by sex. Engaging in domestic/physical activities may substantially lower recurrent strokes in Chinese adult males. And good sleep in females appears to be more important in preventing stroke recurrence.

Sex differences in outcomes after endovascular treatment of patients with vertebrobasilar artery occlusion

BACKGROUND

Current studies on the role of sex in the prognosis of acute vertebrobasilar artery occlusion (VBAO) are limited. We aimed to explore whether there are sex differences on outcomes in patients treated with endovascular therapy (EVT) for VBAO.

METHODS

Patients from December 2015 to December 2018 with acute VBAO within 24 h of the estimated occlusion time in 21 stroke centers in China were retrospectively analyzed. Baseline data between sexes were compared in the total population cohort and propensity score (PS)-matched cohort. Multivariate logistic regression and ordinal regression were used to analyze the association of sex with outcomes. Mixed-effects regression model was performed for changes in modified Rankin Scale (mRS) scores in men and women from 90 days to 1 year after discharge.

RESULTS

A total of 577 patients (28.4% women) were finally included. Multivariate logistic regression showed that women had a lower probability of favorable outcome (mRS score 0-3 at 90 days; OR 0.544; 95% CI 0.329-0.899) and functional independence (mRS score 0-2 at 90 days; OR 0.391; 95% CI 0.228-0.670) as well as a higher possibility of shifting to worse mRS (OR 1.484; 95% CI 1.020-2.158) than men. After PS matching, 391 patients (39.4% women) were analyzed, confirming the same results regarding favorable outcome (OR 0.580; 95% CI 0.344-0.977), functional independence (OR 0.394; 95% CI 0.218-0.712), and shift mRS (OR 1.504; 95% CI 1.023-2.210). However, the results of repeated ANOVA showed that men and women had a comparable functional recovery from 90 days to 1 year.

CONCLUSIONS

Stroke due to VBAO treated with EVT is associated with worse outcomes in women than in men. However, men and women showed similar long-term improvement trends.

Systematic review on sex differences for drug use after stroke

INTRODUCTION

Systematic reviews and meta-analyses have synthetized the existing knowledge on sex-differences for the risk of stroke, the most recent ones highlighting an increased risk of stroke for women. However, whether there are sex differences in post stroke treatment in real world setting is not known. We therefore conducted a systematic review on this subject.

MATERIAL AND METHODS

All observational studies on sex-differences in poststroke drug use published until 20/04/2021 were identified from PubMed and Scopus. Articles were selected and assessed by two independent readers; a third resolved disagreements. Data extraction was performed using a standardized form; articles quality was assessed using the STROBE guidelines. The study is registered on PROSPERO: CRD42021250256.

RESULTS

Of the 604 identified articles, 33 were included. Most were published before 2015 and presented methodological limitations. These limitations differentially affected studies with statistically significant and non-significant results, questioning the reliability of conflicting results. The exploration of sex-differences in drug use varied between therapeutic classes (articles focusing on thrombolytics: 25; antithrombotics: 23; on antihypertensive: 13; lipid-lowering drugs: 9). After stroke, women were found less likely to be prescribed antithrombotics in 48% of the articles investigating this class, and lipid-lowering drugs in 56%. Thirty-one percent of the studies concerning antihypertensive drugs reported the opposite.

DISCUSSION/CONCLUSION

In women, a lack of use of antithrombotics and lipid-lowering drugs after stroke seem to emerge from this review. Conflicting results regarding sex-differences might relate to methodological limitations in studies with no statistical differences, and advocate for the conduct of newer and more comprehensive research.

Sex Differences in Intracranial Atherosclerotic Plaques Among Patients With Ischemic Stroke

Objective

High-risk intracranial arterial plaques are the most common cause of ischemic stroke and their characteristics vary between male and female patients. However, sex differences in intracranial plaques among symptomatic patients have rarely been discussed. This study aimed to evaluate sex differences in intracranial atherosclerotic plaques among Chinese patients with cerebral ischemia.

Methods

One hundred and ten patients who experienced ischemic events underwent 3T cardiovascular magnetic resonance vessel wall scanning for the evaluation of intracranial atherosclerotic disease. Each plaque was classified according to its likelihood of causing a stroke (as culprit, uncertain, or non-culprit). The outer wall area (OWA) and lumen area of the lesion and reference sites were measured, and the wall and plaque areas, remodeling ratio, and plaque burden (characterized by a normalized wall index) were further calculated. The composition (T1 hyperintensity, enhancement) and morphology (surface irregularity) of each plaque were analyzed. Sex differences in intracranial plaque characteristics were compared between male and female patient groups.

Results

Overall, 311 plaques were detected in 110 patients with ischemic stroke (81 and 29 male and female patients, respectively). The OWA (P &lt; 0.001) and wall area (P &lt; 0.001) of intracranial arterial lesions were significantly larger in male patients. Regarding culprit plaques, the plaque burden in male patients was similar to that in female patients (P = 0.178, odds ratio [OR]: 0.168, 95% confidence interval [CI]: −0.020 to 0.107). However, the prevalence of plaque T1 hyperintensity was significantly higher than that in female patients (P = 0.005, OR: 15.362, 95% CI: 2.280–103.49). In the overall ischemic stroke sample, intracranial T1 hyperintensity was associated with male sex (OR: 13.480, 95% CI: 2.444–74.354, P = 0.003), systolic blood pressure (OR: 1.019, 95% CI: 1.002–1.036, P = 0.031), and current smoker (OR: 3.245, 95% CI: 1.097–9.598, P = 0.033).

Conclusion

For patients with ischemic stroke, the intracranial plaque burden in male patients was similar to that in female patients; however, the plaque characteristics in male patients are associated with higher risk, especially in culprit plaques.

Stroke Outcomes in Women: A Population-Based Cohort Study

BACKGROUND

Limited data are available on sex-related disparities in long-term outcomes after stroke. We estimated sex differences in various stroke long-term outcomes among survivors after stroke in a prospective 25-year follow-up study.

METHODS

Individuals recruited to the South London Stroke Register, an ongoing multi-ethnic urban-based population stroke register, from 1995 onward were included in the analyses (n=6687). The outcomes were death, subsequent stroke, activity of daily living, instrumental activity of daily living, cognitive impairment, depression, anxiety, and health-related quality of life. Kaplan-Meier curves were generated for mortality, stroke recurrence, and recurrence-free survival by sex and Cox proportional hazards model used to model sex differences up to 25 years. Generalized estimating equation were used to model sex differences in risk of self-reported stroke outcomes over 10 years poststroke outcomes, adjusting for age, preexisting activity of daily living, case-mix, stroke subtypes, and other potential confounding risk factors.

RESULTS

There were 49% women (mean age, 72 years; SD, 15.6) and 51% men (mean age, 67 years; SD, 14.3) in 6687 participants. Compared with men, women had 9% (95% CI, 3%-15%) lower covariate-adjusted risk of death and 6% (0%-13%) lower risk of stroke recurrence or death. Generally, women had significantly poorer outcomes in activity of daily living and anxiety than men, and the sex differences persisted to up to 5 years after stroke. Women also had poorer health-related quality of life in physical (β=-2.06 [95% CI, -3.01 to -1.10]) and mental domains (β=-1.48 [95% CI, -2.44 to -0.52]). Although not significant, there was a suggestive trend for poorer outcomes in cognitive impairment and depression in women. No significant difference in stroke recurrence were found between men and women.

CONCLUSIONS

Female patients with stroke tended to have better covariate-adjusted survival but poorer outcomes among survivors than male patients, with deficits persisting to up to 5 years poststroke.

New strategy for clinical etiologic diagnosis of acute ischemic stroke and blood biomarker discovery based on machine learning

Acute ischemic stroke (AIS) is a syndrome characterized by high morbidity, prevalence, mortality, recurrence and disability. The longer the delay before proper treatment of a stroke, the greater the likelihood of brain damage and disability. Computed tomography and nuclear magnetic resonance are the primary choices for fast diagnosis of AIS in the early stage, which can provide certain information about infarction location and degree, and even the vascular distribution of lesions responsible for strokes. However, this is quite difficult to achieve in small clinics or at-home diagnoses. Hematology tests could quickly obtain a large number of pathology-related indicators, and offer an effective method for rapid AIS diagnosis when combined with the machine learning technique. To explore a reliable, predictable method for early clinical etiologic diagnosis of AIS, a retrospective study was deployed on 456 AIS patients at the early stage and 28 reference subjects without the symptoms of AIS, by means of the selected significant traits amongst 64 clinical and blood traits in conjunction with powerful machine learning strategies. Five representative biomarkers were closely related to cardioembolic (CE), 22 to large artery atherosclerosis (LAA), and 15 to small vessel occlusion (SVO) strokes, respectively. With these biomarkers, different etiologic subtypes of stroke patients were determined with high accuracy of >0.73, sensitivity of >0.73, and specificity of >0.70, which was comparable to the accuracy obtained in the emergency department by clinical diagnosis. The proposed method may offer an alternative strategy for the etiologic diagnosis of AIS at the early stage when integrating significant blood traits into machine learning.

A rapid and safe strategy was proposed for clinical etiologic diagnosis of acute ischemic stroke at the early stage using clinical hematology traits and machine learning. Blood biomarkers were effectively identified.

Call to Action for Enhanced Equity: Racial/Ethnic Diversity and Sex Differences in Stroke Symptoms

Background

Fundamental aspects of human identity may play a role in the presentation of stroke symptoms and, consequently, stroke recognition. Strokes must be recognized and treated expeditiously, as delays result in poorer outcomes. It is known that sex plays a role in the presentation of symptoms, such that non-traditional symptoms are more commonly observed among women. However, factors such as geographical location and race/ethnicity, and the interactions between these various factors, need to be considered. This will provide an intersectional approach.

Methods

A systematic review and meta-analysis of the literature was conducted to investigate differences in the presentation of stroke symptoms between sexes. Using PubMed and Embase, a search involving the components sex, symptoms and stroke was completed and yielded 26 full-text manuscripts.

Results

Our findings indicate that there is substantial overlap in stroke symptom presentation in men and women. Nonetheless, some differences in the clinical manifestations of stroke were observed. In addition, it was discovered that only three studies were conducted outside of North America and Europe. Furthermore, only two studies reported symptoms based on both sex and racial/ethnic group.

Conclusion

These findings indicate a research gap and call for increased research in order to uncover the possible interactions between sex and race/ethnicity in an intersectional approach. Resultantly, stroke recognition could be improved and greater equity in healthcare can be achieved.

Prediction Model of Ischemic Stroke Recurrence Using PSO-LSTM in Mobile Medical Monitoring System

Aiming at the problems of low prediction accuracy and low sensitivity of traditional ischemic stroke recurrence prediction methods, which limits its application range, by introducing an adaptive particle swarm optimization (PSO) algorithm into the Long and Short-Term Memory (LSTM) model, a prediction model of ischemic stroke recurrence using deep learning in mobile medical monitoring system is proposed. First, based on the clustering idea, the particles are divided into local optimal particles and ordinary particles according to the characteristic information and distribution of different particles. By updating the particles with different strategies, the diversity of the population is improved and the problem of local optimal solution is eliminated. Then, by introducing the adaptive PSO algorithm into the LSTM, the PSO-LSTM prediction model is constructed. The optimal super parameters of the model are determined quickly and accurately, and the model is trained combined with the patient's clinical data. Finally, by using SMOTE method to process the original data, the imbalance of positive and negative sample data is eliminated. Under the same conditions, the proposed PSO-LSTM prediction model is compared with two traditional LSTM models. The results show that the prediction accuracy of PSO-LSTM model is 92.0%, which is better than two comparison models. The effective prediction of ischemic stroke recurrence is realized.

Pre-stroke Physical Inactivity and Stroke Severity in Male and Female Patients

Introduction

Females experience more severe ischemic strokes than do males. A higher pre-stroke physical activity level is associated with less severe stroke. The primary aim of this study was to explore the association between pre-stroke physical inactivity and stroke severity in male and female patients.

Methods

This was a retrospective, registry-based study. The data were retrieved from two stroke registries from 2014 to 2019. The primary explanatory variable was physical activity level before the stroke, assessed using the Saltin-Grimby Physical Activity Level Scale. The outcome was moderate to severe stroke at hospital admission, assessed using the National Institutes of Health Stroke Scale (NIHSS). A moderate to severe stroke was defined as a NIHSS score of ≥6. Binary logistic regression analysis was performed to explore if physical inactivity before the stroke could explain stroke severity in male and female patients.

Results

In total, we included 4,535 patients with ischemic stroke. Female patients (n = 2,145) had a mean age of 76 years, 35% had a moderate to severe stroke, and 64% were physically inactive pre-stroke. Male patients (n = 2,390) had a mean age of 72 years, 25% had a moderate to severe stroke, and 49% were physically inactive pre-stroke. Physical inactivity was associated with higher odds for moderate to severe stroke in both sexes (females' odds ratio [OR], 2.7, 95% confidence interval [CI]: 2.2–3.3, p < 0.001 and males' OR, 2.06, 95% CI: 1.7–2.5, p < 0.001). The association remained significant in the adjusted models.

Conclusions

Physically inactive females and males had higher odds of experiencing a moderate to severe stroke. However, the OR of female patients was somewhat higher than that of male patients.

Sex-Specific Differences in Pre-Stroke Characteristics Reveal Vulnerability of Elderly Women

While the sexually dimorphic character of ischemic stroke has been acknowledged along several dimensions, age-specific sex disparities regarding pre-stroke characteristics in particular have received comparatively little attention. This study aimed to identify age-dependent associations between sex and risk factors, premorbidity, and living situation in patients with ischemic stroke to foster the continuing development of dedicated preventative strategies. In a retrospective single-center study, data of patients with acute ischemic stroke (AIS) admitted to the Department of Neurology, University Hospital Mannheim, Germany, between June 2004−June 2020 were included; AIS frequency, vascular risk factors, premorbidity, living situation, and stroke etiology were analyzed across sexes and different age spectra. From a total of 11,003 patients included in the study, 44.1% were female. Women aged >70−≤90 years showed a pronounced increase in stroke frequency, lived alone significantly more frequently, and had a significantly higher degree of pre-stroke disability than men; however, only hypertension and atrial fibrillation were more prevalent in women in this age segment. The seventh and eighth decades are a critical time in which the pre-stroke risk profile changes resulting in an increase in stroke morbidity in women. This emphasizes the relevance of and need for an approach to stroke prevention that is both targeted and integrative.

Sex Differences in Presentation of Stroke: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Women have worse outcomes than men after stroke. Differences in presentation may lead to misdiagnosis and, in part, explain these disparities. We investigated whether there are sex differences in clinical presentation of acute stroke or transient ischemic attack.

METHODS

We conducted a systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Inclusion criteria were (1) cohort, cross-sectional, case-control, or randomized controlled trial design; (2) admission for (suspicion of) ischemic or hemorrhagic stroke or transient ischemic attack; and (3) comparisons possible between sexes in ≥1 nonfocal or focal acute stroke symptom(s). A random-effects model was used for our analyses. We performed sensitivity and subanalyses to help explain heterogeneity and used the Newcastle-Ottawa Scale to assess bias.

RESULTS

We included 60 studies (n=582 844; 50% women). In women, headache (pooled odds ratio [OR], 1.24 [95% CI, 1.11-1.39]; I²=75.2%; 30 studies) occurred more frequently than in men with any type of stroke, as well as changes in consciousness/mental status (OR, 1.38 [95% CI, 1.19-1.61]; I²=95.0%; 17 studies) and coma/stupor (OR, 1.39 [95% CI, 1.25-1.55]; I²=27.0%; 13 studies). Aspecific or other neurological symptoms (nonrotatory dizziness and non-neurological symptoms) occurred less frequently in women (OR, 0.96 [95% CI, 0.94-0.97]; I²=0.1%; 5 studies). Overall, the presence of focal symptoms was not associated with sex (pooled OR, 1.03) although dysarthria (OR, 1.14 [95% CI, 1.04-1.24]; I²=48.6%; 11 studies) and vertigo (OR, 1.23 [95% CI, 1.13-1.34]; I²=44.0%; 8 studies) occurred more frequently, whereas symptoms of paresis/hemiparesis (OR, 0.73 [95% CI, 0.54-0.97]; I²=72.6%; 7 studies) and focal visual disturbances (OR, 0.83 [95% CI, 0.70-0.99]; I²=62.8%; 16 studies) occurred less frequently in women compared with men with any type of stroke. Most studies contained possible sources of bias.

CONCLUSIONS

There may be substantive differences in nonfocal and focal stroke symptoms between men and women presenting with acute stroke or transient ischemic attack, but sufficiently high-quality studies are lacking. More studies are needed to address this because sex differences in presentation may lead to misdiagnosis and undertreatment.

Sex-Specific MicroRNAs in Neurovascular Units in Ischemic Stroke

Accumulating evidence pinpoints sex differences in stroke incidence, etiology and outcome. Therefore, more understanding of the sex-specific mechanisms that lead to ischemic stroke and aggravation of secondary damage after stroke is needed. Our current mechanistic understanding of cerebral ischemia states that endothelial quiescence in neurovascular units (NVUs) is a major physiological parameter affecting the cellular response to neuron, astrocyte and vascular smooth muscle cell (VSMC) injury. Although a hallmark of the response to injury in these cells is transcriptional activation, noncoding RNAs such as microRNAs exhibit cell-type and context dependent regulation of gene expression at the post-transcriptional level. This review assesses whether sex-specific microRNA expression (either derived from X-chromosome loci following incomplete X-chromosome inactivation or regulated by estrogen in their biogenesis) in these cells controls NVU quiescence, and as such, could differentiate stroke pathophysiology in women compared to men. Their adverse expression was found to decrease tight junction affinity in endothelial cells and activate VSMC proliferation, while their regulation of paracrine astrocyte signaling was shown to neutralize sex-specific apoptotic pathways in neurons. As such, these microRNAs have cell type-specific functions in astrocytes and vascular cells which act on one another, thereby affecting the cell viability of neurons. Furthermore, these microRNAs display actual and potential clinical implications as diagnostic and prognostic biomarkers in ischemic stroke and in predicting therapeutic response to antiplatelet therapy. In conclusion, this review improves the current mechanistic understanding of the molecular mechanisms leading to ischemic stroke in women and highlights the clinical promise of sex-specific microRNAs as novel diagnostic biomarkers for (silent) ischemic stroke.

Female Stroke: Sex Differences in Acute Treatment and Early Outcomes of Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Men and women are differently affected by acute ischemic stroke (AIS) in many aspects. Prior studies on sex disparities were limited by moderate sample sizes, varying years of data acquisition, and inconsistent inclusions of covariates leading to controversial findings. We aimed to analyze sex differences in AIS severity, treatments, and early outcome and to systematically evaluate the effect of important covariates in a large German stroke registry.

METHODS

Analyses were based on the Stroke Registry of Northwestern Germany from 2000 to 2018. We focused on admission-stroke severity and disability, acute recanalization treatment, and early stroke outcomes. Potential sex divergences were investigated via odds ratio (OR) using logistic regression models. Covariates were introduced in 3 steps: (1) base models (age and admission year), (2) partially adjusted models (additionally corrected for acute stroke severity and recanalization treatment), (3) fully adjusted models (additionally adjusted for onset-to-admission time interval, prestroke functional status, comorbidities, and stroke cause). Models were separately fitted for the periods 2000 to 2009 and 2010 to 2018.

RESULTS

Data from 761 106 patients with AIS were included. In fully adjusted models, there were no sex differences with respect to treatment with intravenous thrombolysis (2000-2009: OR, 0.99 [95% CI, 0.94-1.03]; 2010-2018: OR, 1.0 [0.98-1.02]), but women were more likely to receive intraarterial therapy (2010-2018: OR, 1.12 [1.08-1.15]). Despite higher disability on admission (2000-2009: OR, 1.10 [1.07-1.13]; 2010-2018: OR, 1.09 [1.07-1.10]), female patients were more likely to be discharged with a favorable functional outcome (2003-2009: OR, 1.05 [1.02-1.09]; 2010-2018: OR, 1.05 [1.04-1.07]) and experienced lower in-hospital mortality (2000-2009: OR, 0.92 [0.86-0.97]; 2010-2018: OR, 0.91 [0.88-0.93]).

CONCLUSIONS

Female patients with AIS have a higher chance of receiving intraarterial treatment that cannot be explained by clinical characteristics, such as age, premorbid disability, stroke severity, or cause. Women have a more favorable in-hospital recovery than men because their higher disability upon admission was followed by a lower in-hospital mortality and a higher likelihood of favorable functional outcome at discharge after adjustment for covariates.

Carotid Endarterectomy is often not Possible after an Unheralded Stroke: Unheralded Stroke in Carotid Artery Stenosis

OBJECTIVES

The ongoing literature recommends carotid endarterectomy (CEA) primarily for patients with neurological symptoms, however CEA can be precluded by the onset of a severe stroke or a total carotid occlusion. The present study aims to evaluate the effect of unheralded strokes in patients with a previously asymptomatic carotid stenosis (ACS) possibly considered for CEA.

MATERIALS AND METHODS

From 2009 to 2019, patients with an unheralded stroke from an ACS were considered. By neurological examination, patients were divided in unfit-for-CEA (uCEA) - either for the severity of the stroke (according to modified Rankin-Scale - mRS) or the onset of a total carotid occlusion - and patients submitted to CEA. Predictors for uCEA and stroke severity were evaluated.

RESULTS

Over a total of 532 patients with symptomatic carotid stenosis, 277 (52%) with unheralded stroke were included in the study. One hundred and one (36%) were considered uCEA: 64(23%) due to their neurological conditions (mRS:5) and 37 (13%) because of the onset of carotid occlusion. One hundred seventy-six (64%) patients underwent CEA. The preoperative medical therapy was similar in uCEA vs CEA patients. Age≥80 years and female sex were independently associated with uCEA (OR:5.9, 95%CI:3.1-11.4, P<.01; OR:3.9, 95%CI:2.0-7.6, P<.01. respectively). Patients submitted to CEA had mRS: 0-2 in 102(37%) cases and mRS:3-4 in 74 (27%). The contralateral carotid occlusion (CCO) was independently associated with mRS:3-4 (OR:8.4, 95%CI 1.8-79, P=.01). Postoperative stroke rate after CEA was 2.9% (4/167); patients with preoperative mRS:3-4 had a higher risk for postoperative stroke compared to those with mRS:0-2 (5.9% vs. 0%. P=.02).

CONCLUSIONS

An unheralded stroke in patients with ACS leads to a severe neurological damage in more than half of cases, either precluding CEA (36%) or increasing the risk of postoperative complications (27%). Female sex, age≥80 and CCO are independent predictors of these occurrences and should be considered in ACS patients.

Acute ischaemic stroke in the absence of established vascular risk factors: Patient characteristics, stroke mechanism and long-term outcome

BACKGROUND AND PURPOSE

Some acute ischaemic stroke (AIS) patients do not display established vascular risk factors (EVRFs). The aim was to assess their clinical characteristics, stroke subtype etiological classification and long-term outcome.

METHODS

All consecutive AIS patients from the Acute Stroke Registry of Lausanne (2003-2018) were retrospectively analyzed with complete assessment of the following EVRFs: hypertension, diabetes, major cardioembolic sources, dyslipidemia, smoking, obesity, alcohol abuse, previous stroke/transient ischaemic attack and depression/psychosis. Patients without EVRFs were compared to patients with one or more EVRFs using appropriate statistical models.

RESULTS

Of 4889 included patients, 103 (2.1%) had no EVRFs. In multiple regression analysis, patients without EVRFs were significantly younger (odds ratio [OR] 0.13; 95% confidence interval [CI] 0.08-0.20) and had more multiterritorial strokes (OR 3.38; 95% CI 1.26-9.05). Strokes were more often related to patent foramen ovale (PFO) (OR 3.02; 95% CI 1.44-6.32) and less to atherosclerosis, cardioembolism or small vessel disease. In patients <55 years old, PFO (OR 2.76; 95% CI 1.50-5.08) and contraceptive use in females (OR 2.75; 95% CI 1.40-5.41) were more frequent, whereas sleep apnea syndrome (OR 0.09; 95% CI 0.01-0.63) was less. In patients ≥55 years, female sex (OR 2.84; 95% CI 1.43-5.65) and active cancer (OR 3.27; 95% CI 1.34-7.94) were more prevalent. At 12 months, patients without EVRFs had worse adjusted functional outcome (Rankin shift OR_adj 0.63; 95% CI 0.42-0.95) and higher rate of recurrence and death (adjusted hazard ratio 2.11; 95% CI 1.19-3.74).

CONCLUSIONS

In a consecutive cohort of AIS patients, only 2% showed no EVRFs. PFO and contraceptive use exhibited a strong association with the absence of EVRFs in younger patients and female sex and active cancer in elderly patients. Our findings highlight the importance of searching for previously unknown risk factors and/or unusual stroke mechanisms in patients without EVRFs.