Modification effects of immigration status and comorbidities on associations of heat and heatwave with stroke morbidity.

BACKGROUND: Heat and heatwave have been associated with stroke morbidity, but it is still unclear whether immigrants from different geographic regions and patients with comorbidity are more vulnerable to heat and heatwave. METHODS: Time-stratified case-crossover design combined with generalized additive quasi-Poisson models were used to quantify the relative risks (RR) of heat and heatwave on first-ever stroke morbidity during 0-7 lag days. Attributable fractions (AF) were estimated to assess the first-ever stroke morbidity burden due to heat and heatwave. Stratified analyses for sex, age, disease subtypes, resident characteristics, and comorbidity type were performed to identify potential modification effects. RESULTS: Heat and heatwave were associated with first-ever stroke morbidity, with the AF of 2.535% (95% eCI: 0.748, 4.205) and 2.409% (95% CI: 1.228, 3.400), respectively. Among northern and southern immigrants, the AF for heat was 2.806% (0.031, 5.069) and 2.798% (0.757, 4.428), respectively, and the AF for heatwave was 2.918% (0.561, 4.618) and 2.387% (1.174, 3.398), respectively, but the effects of both on natives were statistically insignificant. Among patients with hypertension, dyslipidemia, or diabetes, the AF for heat was 3.318% (1.225, 5.007), 4.237% (1.037, 6.770), and 4.860% (1.171, 7.827), respectively, and the AF for heatwave was 2.960% (1.701, 3.993), 2.771% (0.704, 4.308), and 2.652% (0.653, 4.185), respectively. However, the effects of both on patients without comorbidity were statistically insignificant. CONCLUSION: Heat and heatwave are associated with an increased risk of first-ever stroke morbidity among immigrants and those with comorbid hypertension, dyslipidemia, or diabetes, with the effects primarily due to non-native individuals.

Long daytime napping: A silent danger for hypertensive individuals.

BACKGROUND AND PURPOSE: Hypertension significantly contributes to stroke. Previous research has indicated a connection between daytime napping and stroke. Research on the connection between daytime napping duration and first stroke in hypertensive individuals is lacking nevertheless. METHODS: This research, which ran from 24 August 2013 to 31 December 2022, recruited 11,252 individuals with hypertension and without a history of stroke from the China Stroke Primary Prevention Trial. To determine the relationship between daytime napping duration and stroke onset in hypertensive individuals, we conducted analyses for threshold effects, multivariate-adjusted Cox proportional hazard regression models, and Kaplan-Meier survival curves. RESULTS: The duration of daytime napping (<75 min) was positively correlated with stroke risk; beyond 75 min, the risk did not increase further. When compared to hypertensive individuals who napped for 1-30 min, daytime napping 31-60 min (hazard ratio [HR] = 1.27, 95% confidence interval [CI] = 1.06-1.53) and >60 min (HR = 1.37, 95% CI = 1.14-1.65) were substantially related with a greater risk of first stroke. Additionally, this correlation was absent in cases of hemorrhagic stroke, but present in cases of ischemic stroke, specifically for hypertensive individuals who napped for 31-60 min or >60 min (p < 0.05). Kaplan-Meier survival curves displayed that hypertensive individuals who extended daytime napping had an elevated incidence of stroke. CONCLUSIONS: Hypertensive individuals who take longer daytime naps (>30 min) are at an elevated risk of stroke onset, particularly ischemic stroke, irrespective of other factors.

Associations of Plasma Metabolites With Risks of Incident Stroke and Its Subtypes in Chinese Adults.

BACKGROUND: Metabolomics studies have identified various metabolic markers associated with stroke risk, yet much uncertainty persists regarding heterogeneity in these associations between different stroke subtypes. We aimed to examine metabolic profiles associated with incident stroke and its subtypes in Chinese adults. METHODS AND RESULTS: We performed a nested case-control study within the Dongfeng-Tongji cohort, including 1029 and 266 incident cases of ischemic stroke (IS) and hemorrhagic stroke (HS), respectively, with a mean follow-up period of 6.1±2.3 years. Fifty-five metabolites in fasting plasma were measured by ultra-high-performance liquid chromatography-mass spectrometry. We examined the associations of metabolites with the risks of total stroke, IS, and HS, with a focus on the comparison of associations of plasma metabolite with IS and HS, using conditional logistic regression. We found that increased levels of asymmetrical/symmetrical dimethylarginine and glutamate were significantly associated with elevated risk of total stroke (odds ratios and 95%, 1.20 [1.08-1.34] and 1.22 [1.09-1.36], respectively; both Benjamini-Hochberg-adjusted P <0.05). When examining stroke subtypes, asymmetrical/symmetrical dimethylarginine was nominally associated with both IS and HS (odds ratios [95% CIs]: 1.16 [1.03-1.31] and 1.39 [1.07-1.81], respectively), while glutamate was associated with only IS (odds ratios [95% CI]: 1.26 [1.11-1.43]). The associations of glutamate with IS risk were significantly stronger among participants with hypertension and diabetes than among those without these diseases (both P for interaction <0.05). CONCLUSIONS: This study validated the positive associations of asymmetrical/symmetrical dimethylarginine and glutamate with stroke risk, mainly that of IS, in a Chinese population, and revealed a novel unanimous association of with both IS and HS. Our findings provided potential intervention targets for stroke prevention.

Seasonal variability of lesions distribution in acute ischemic stroke: A retrospective study.

Seasonal variability could have an impact on the incidence and outcome of stroke. However, little is known about the correlation between seasonal variability and location of acute cerebral infarction. This study aimed to explore the relationship between onset season and the lesions distribution of acute ischemic stroke (AIS). We retrospectively analysis data from 1488 AIS patients admitted to the Second Hospital of Tianjin Medical University from 2018 to 2022. All subjects completed head magnetic resonance imaging examination (MRI) and were divided into four groups according to the onset seasons. The lesions distribution of AIS was evaluated for anterior/posterior/double circulation infarction (DCI), unilateral/bilateral infarctions, and single/multiple cerebral infarctions based on MRI. Logistic regression models were employed to assess the association of season with lesions distribution of AIS. Subgroup analysis was performed in different stroke subtypes. Of 1488 patients, 387 (26.0%) AIS occurred in spring, 425 (28.6%) in summer, 331 (22.2%) in autumn and 345 (23.2%) in winter. Multivariate logistic regression demonstrated that the winter group had 2.15 times (95% CI:1.44-3.21) risk of multiple infarctions, 2.69 times (95% CI:1.80-4.02) of bilateral infarctions and 1.54 times (95% CI:1.05-2.26) of DCI compared with summer group, respectively. Subgroup analysis showed an increased risk of multiple (p < 0.01) or bilateral infarctions (p < 0.01) in small-artery occlusion (SAO) subtype, and higher risk of bilateral infarctions (p < 0.01) or DCI (p < 0.05) in large artery atherosclerosis (LAA) subtype during winter. No significant associations of season with lesions distribution in cardioembolism subtype. Our study highlighted a prominent seasonal variability in the lesions distribution of AIS, particularly in LAA and SAO subtypes. The findings could help to formulating meteorological risk warning strategies for different subtypes.

A protective role of genetically predicted sex hormone-binding globulin on stroke.

Introduction: The role of sex hormone-binding globulin (SHBG) on stroke has been investigated in several observational studies. To provide the causal estimates of SHBG on stroke and its subtypes, bi-directional and multivariable Mendelian randomization (MR) analyses are performed. Methods: The genetic instruments of SHBG were obtained from the UK Biobank. Outcome datasets for stroke and its subtypes were taken from the MEGASTROKE Consortium. The main analysis used in this study is the inverse variance weighting, complemented by other sensitivity approaches to verify the conformity of findings. Results: We found that the risk of stroke grew by 13% (odd ratio [OR] = 0.87, 95% confidence interval [CI] = 0.79-0.95, P = 0.0041) and the risk of ischemic stroke grew by 15% (OR = 0.85, 95%CI = 0.77-0.95, P = 0.0038) caused by genetically predicted SHBG. The causal association remains robust in the reverse MR and multivariable MR analyses for stroke (reverse MR: all P > 0.01 for the IVW method; MVMR: OR = 0.72, 95%CI = 0.59-0.87, P = 0.0011) and ischemic stroke (reverse MR: all P > 0.01 for IVW; MVMR: OR = 0.70, 95%CI = 0.56-0.86, P = 0.0007). Conclusion: Our MR study provides novel evidence that SHBG has an inverse association with stroke and ischemic stroke, exerting protective effects on stroke.

Clinical impact of body mass index on outcomes of ischemic and hemorrhagic strokes.

BACKGROUND AND AIM: To investigate the prognostic implication of body mass index (BMI) on clinical outcomes after acute ischemic and hemorrhagic stroke. METHODS: The subjects of the study included adult patients with available baseline body weight and height data who had suffered an acute stroke and were registered in the Japan Stroke Data Bank-a hospital-based, multicenter stroke registration database-between January 2006 and December 2020. The outcome measures included unfavorable outcomes defined as a modified Rankin Scale (mRS) score of 5-6 and favorable outcomes (mRS 0-2) at discharge, and in-hospital mortality. Mixed effects logistic regression analysis was conducted to determine the relationship between BMI categories (underweight, normal weight, overweight, class I obesity, class II obesity; <18.5, 18.5-23.0, 23.0-25.0, 25-30, ⩾30 kg/m2) and the outcomes, after adjustment for covariates. RESULTS: A total of 56,230 patients were assigned to one of the following groups: ischemic stroke (IS, n = 43,668), intracerebral hemorrhage (ICH, n = 9741), and subarachnoid hemorrhage (SAH, n = 2821). In the IS group, being underweight was associated with an increased likelihood of unfavorable outcomes (odds ratio, 1.47 (95% confidence interval (CI):1.31-1.65)) and in-hospital mortality (1.55 (1.31-1.83)) compared to outcomes in those with normal weight. Being overweight was associated with an increased likelihood of favorable outcomes (1.09 (1.01-1.18)). Similar associations were observed between underweight and these outcomes in specific IS subtypes (cardioembolic stroke, large artery stroke, and small-vessel occlusion). Patients with a BMI ⩾30.0 kg/m2 was associated with an increased likelihood of unfavorable outcomes (1.44 (1.01-2.17)) and in-hospital mortality (2.42 (1.26-4.65)) in large artery stroke. In patients with ICH, but not those with SAH, being underweight was associated with an increased likelihood of unfavorable outcomes (1.41 (1.01-1.99)). CONCLUSIONS: BMI substantially impacts functional outcomes following IS and ICH. Lower BMI consistently affected post-stroke disability and mortality, while higher BMI values similarly affected these outcomes after large artery stroke.

Tobacco use and risk of acute stroke in 32 countries in the INTERSTROKE study: a case-control study.

Background: Smoking is a major risk factor for the global burden of stroke. We have previously reported a global population attributable risk (PAR) of stroke of 12.4% associated with current smoking. In this study we aimed to explore the association of current tobacco use with different types of tobacco exposure and environmental tobacco smoke (ETS) exposure on the risk of stroke and stroke subtypes, and by regions and country income levels. Methods: The INTERSTROKE study is a case-control study of acute first stroke and was undertaken with 13,462 stroke cases and 13,488 controls recruited between January 11, 2007 and August 8, 2015 in 32 countries worldwide. Association of risk of tobacco use and ETS exposure were analysed with overall stroke, ischemic and intracerebral hemorrhage (ICH), and with TOAST etiological stroke subtypes (large vessel, small vessel, cardioembolism, and undetermined). Findings: Current smoking was associated with an increased risk of all stroke (odds ratio [OR] 1.64, 95% CI 1.46-1.84), and had a stronger association with ischemic stroke (OR 1.85, 95% CI 1.61-2.11) than ICH (OR 1.19 95% CI 1.00-1.41). The OR and PAR of stroke among current smokers varied significantly between regions and income levels with high income countries (HIC) having the highest odds (OR 3.02 95% CI 2.24-4.10) and PAR (18.6%, 15.1-22.8%). Among etiological subtypes of ischemic stroke, the strongest association of current smoking was seen for large vessel stroke (OR 2.16, 95% CI 1.63-2.87) and undetermined cause (OR 1.97, 95% CI 1.55-2.50). Both filtered (OR 1.73, 95% CI 1.50-1.99) and non-filtered (OR 2.59, 95% CI 1.79-3.77) cigarettes were associated with stroke risk. ETS exposure increased the risk of stroke in a dose-dependent manner, exposure for more than 10 h per week increased risk for all stroke (OR 1.95, 95% CI 1.69-2.27), ischemic stroke (OR 1.89, 95% CI 1.59-2.24) and ICH (OR 2.00, 95% CI 1.60-2.50). Interpretation: There are significant variations in the magnitude of risk and PAR of stroke according to the types of tobacco used, active and ETS exposure, and countries with different income levels. Specific strategies to discourage tobacco use by any form and to build a smoke free environment should be implemented to ease the global burden of stroke. Funding: The Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Västra Götaland, and through unrestricted grants from several pharmaceutical companies with major contributions from Astra Zeneca, Boehringer Ingelheim (Canada), Pfizer (Canada), MERCK, Sharp and Dohme, Swedish Heart and Lung Foundation, UK Chest, and UK Heart and Stroke.

Global, regional, and national burden of stroke attributable to extreme low temperatures, 1990-2019: A global analysis.

BACKGROUND: Extreme ambient temperatures have been linked to increased risks of stroke morbidity and mortality. However, global estimates of the burden of stroke due to extreme low temperatures are not well-defined. AIMS: This study aimed to determine the global burden of stroke due to extreme low temperatures and its spatiotemporal trend from 1990 to 2019. METHODS: Based on the Global Burden of Disease Study 2019, we obtained global, regional, and national data on deaths, disability-adjusted life years (DALYs), age-standardized mortality rate (ASMR), and age-standardized rate of DALYs (ASDR) of stroke attributed to extreme low temperatures, further stratified by age, sex, and sociodemographic index (SDI). RESULTS: Globally, in 2019, an estimated 474,000 stroke deaths with the corresponding ASMR (6.2 (95% uncertainty interval (UI): 4.6-7.9)) and ASDR (103.9 (95% UI: 77.0-134.5)) per 100,000 population, were attributable to extreme low temperatures. The most significant burden was observed in Central Asia, followed by Eastern Europe and East Asia. From 1990 to 2019, the global burden of stroke and its subtypes (ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage) attributable to extreme low temperatures exhibited a decrease in both ASMR and ASDR. Significant decreases in stroke burden occurred in the high-SDI regions, high-income Asia Pacific, and subarachnoid hemorrhage cases. Moreover, the ASMR and ASDR increased with age and were higher in males than females. CONCLUSION: The global stroke burden due to extreme low temperatures remains high despite a decreasing trend over the past three decades. The stroke burden due to extreme low temperatures was more notable for Central Asia, older people, and the male sex.

Arterial transit artifact as a short-term prognostic indicator in acute ischemic stroke.

BACKGROUND: Arterial transit artifact (ATA) observed on arterial spin labeling (ASL) was recently suggested to be associated with improved functional outcomes following acute ischemic stroke (AIS). AIS is a heterogeneous disease with diverse pathogenic mechanisms depending on the stroke subtype. This study aimed to investigate the association between ATA and 3-month functional outcomes in AIS patients according to etiology subtypes. METHODS: Consecutive patients with AIS were included. All patients underwent ASL MRI with postlabeling delay (PLD) of 1.5 and 2.5 s. ATA was assessed from the ASL images of both PLDs. Stroke etiologic subtypes were determined according to the modified TOAST (Trial of ORG 10172 in Acute Stroke Treatment) classification. Short-term functional outcomes were evaluated using the 3-month modified Rankin scale (mRS). Log-binomial regression was applied to analyze the association between ATA and functional outcomes at 3 months after stroke. RESULTS: Ninety-eight AIS patients (62.73 ± 13.05 years; 68 men) were finally included. ATA was detected in forty-six patients and most frequently seen in the large-artery atherosclerosis (LAA) subtype (35/46). The ATA group exhibited a lower percentage of patients with mRS > 2 compared to the group without ATA (36.5% vs. 19.6%; P < 0.001). ATA was independently associated with better 3-month clinical outcomes (adjusted risk ratio, 0.35[95% CI, 0.16-0.74]) in the multivariate log-binomial regression model. After stratification by TOAST subtypes, a significant association was found between ATA and better outcomes in the LAA subtype (adjusted risk ratio, 0.20[ 95% CI, 0.05-0.72]) but not in cardioembolism and small artery occlusion (SVO) subtype. CONCLUSION: ATA is associated with better outcomes at 3 months in patients with AIS, especially in the LAA subtype, but this association attenuated in the cardioembolism and SVO subtypes.

The added effects of cold spells on stroke admissions: Differential effects on ischemic and hemorrhagic stroke.

BACKGROUND: Epidemiological evidence suggests an association between low ambient temperature and stroke risk, but available data are limited particularly on associations with different stroke subtypes. AIMS: The aim of this study is to estimate the relationship between cold spells and stroke admissions, including the effect of cold spells on different stroke subtypes (ischemic stroke and intracerebral hemorrhage (ICH)). METHODS: A total of 144,405 stroke admissions from the Tianjin Centre for Health and Meteorology Multidisciplinary Innovation in China, covering the period from January 2016 to December 2020, were studied, as well as meteorological and air pollutant data. A generalized additive model with a distributed lag nonlinear model was employed to assess the relationship, considering 12 different definitions of a cold spell based on various temperature thresholds and durations. The analysis controlled for lagged and nonlinear effects of temperature. Analyses were performed on all strokes as well as ischemic stroke and ICH. RESULTS: There was a significant increase in stroke admissions during cold spells. Generally, the increased risk during cold spells increased as the temperature threshold decreased, but was not significantly affected by the duration. The optimal model was obtained using the cold-spell definition based on an average daily temperature below the 10th percentile (0.11°C) for 2 or more consecutive days. According to this model, the effect of cold spells on ischemic stroke admissions had a significant lag effect and was long-lasting, with a single-day effect occurring on lag 7d, peaking on lag 13d (relative risk (RR) = 1.05; 95% confidence interval (CI) = 1.02 to 1.09), and lasting until lag 20d. In contrast, the effect on ICH was immediate and short-lived, with the most significant single-day effect occurring on the current day (RR = 1.17; 95% CI = 1.06 to 1.29) and limited within 3 days. 14.15% of stroke cases could be attributed to cold spells, with ICH exhibiting a higher burden than ischemic stroke except for strict temperature threshold definitions. CONCLUSION: Cold spells are associated with an increased stroke risk. Different patterns of association were seen for different stroke subtypes. The effect on ischemic stroke had a lag effect and a longer duration, whereas the effect on ICH had an immediate effect and a shorter duration. These findings support the development and improvement of stroke cold-spell early warning systems and highlight the importance of public health interventions to mitigate the adverse health impacts of cold spells.

Plateauing atrial fibrillation burden in acute ischemic stroke admissions in the United States from 2010 to 2020.

BACKGROUND: Utilization of oral anticoagulants for acute ischemic stroke (AIS) prevention in patients with atrial fibrillation (AF) increased in the United States over the last decade. Whether this increase has been accompanied by any change in AF prevalence in AIS at the population level remains unknown. The aim of this study is to evaluate trends in AF prevalence in AIS hospitalizations in various age, sex, and racial subgroups over the last decade. METHODS: We used data contained in the 2010-2020 National Inpatient Sample to conduct a serial cross-sectional study. Primary AIS hospitalizations with and without comorbid AF were identified using International Classification of Diseases Codes. Joinpoint regression was used to compute annualized percentage change (APC) in prevalence and to identify points of change in prevalence over time. RESULTS: Of 5,190,148 weighted primary AIS hospitalizations over the study period, 25.1% had comorbid AF. The age- and sex-standardized prevalence of AF in AIS hospitalizations increased across the entire study period 2010-2020 (average APC: 1.3%, 95% confidence interval (CI): 0.8-1.7%). Joinpoint regression showed that prevalence increased in the period 2010-2015 (APC: 2.8%, 95% CI: 1.9-3.9%) but remained stable in the period 2015-2020 (APC: -0.3%, 95% CI: -1.0 to 1.9%). Upon stratification by age and sex, prevalence increased in all age/sex groups from 2010 to 2015 and continued to increase throughout the entire study period in hospitalizations in men 18-39 years (APC: 4.0%, 95% CI: 0.2-7.9%), men 40-59 years (APC: 3.4%, 95% CI: 1.9-4.9%) and women 40-59 years (APC: 4.4%, 95% CI: 2.0-6.8%). In contrast, prevalence declined in hospitalizations in women 60-79 (APC: -1.0%, 95% CI: -0.5 to -1.5%) and women ⩾ 80 years over the period 2015-2020 but plateaued in hospitalizations in similar-aged men over the same period. CONCLUSION: AF prevalence in AIS hospitalizations in the United States increased over the period 2010-2015, then plateaued over the period 2015-2020 due to declining prevalence in hospitalizations in women ⩾ 60 years and plateauing prevalence in hospitalizations in men ⩾ 60 years.

Lung cancer is associated with acute ongoing cerebral ischemia: A population-based study.

BACKGROUND AND OBJECTIVES: Cerebral microinfarcts (CMIs) are the most common type of brain ischemia; however, they are extremely rare in the general population. CMIs can be detected by magnetic resonance diffusion-weighted imaging (MRI-DWI) only for a very short period of approximately 2 weeks after their formation and are associated with an increased stroke risk and cognitive impairment. We aimed to examine CMI detection rate in patients with lung cancer (LC), which is strongly associated with ischemic stroke risk relative to other cancer types. METHODS: We used the Clalit Health Services record (representing more than 5 million patients) to identify adults with LC and breast, pancreatic, or colon cancer (non-lung cancer, NLC) who underwent brain magnetic resonance diffusion (MRI) scan within 5 years following cancer diagnosis. All brain MRI scans were reviewed, and CMIs were documented, as well as cardiovascular risk factors. RESULTS: Our cohort contained a total of 2056 MRI scans of LC patients and 1598 of NLC patients. A total of 143 CMI were found in 73/2056 (3.5%) MRI scans of LC group compared to a total of 29 CMI in 22/1598 (1.4%) MRI scans of NLC (p < 0.01). Cancer type (e.g. LC vs NLC) was the only associated factor with CMI incidence on multivariate analysis. After calculating accumulated risk, we found an incidence of 2.5 CMI per year in LC patients and 0.5 in NLC. DISCUSSION: CMIs are common findings in cancer patients, especially in LC patients and therefore might serve as a marker for occult brain ischemia, cognitive decline, and cancer-related stroke (CRS) risk.

Causal role of lipid metabolome on the risk of ischemic stroke, its etiological subtypes, and long-term outcome: A Mendelian randomization study.

BACKGROUND AND AIMS: The lipid profile is consistently associated with coronary artery disease (CAD) and ischemic stroke (IS). However, the lipoprotein subfractions have not been deeply explored in stroke subtypes, especially in IS outcome. METHODS: We performed two-sample Mendelian randomization (MR) analysis using 92 lipid traits measured by nuclear magnetic resonance in 115,000 subjects from the UK Biobank. Data for genetic associations with IS, its subtypes, and long-term outcome (LTO) were obtained from three cohorts of European ancestry: GIGASTROKE (73,652 cases, 1,234,808 controls), GODS (n = 1791) and GISCOME (n = 6165). Results obtained using CARDIoGRAMPlusC4D were used to identify differences with CAD. RESULTS: Genetically determined low concentration of medium high-density lipoprotein (HDL) particles (odds ratio (OR) = 0.92, 95% CI 0.88-0.96; p = 3.6 × 10-4) and its cholesterol content (OR = 0.92, 95% CI 0.88-0.96; p = 1.9 × 10-4) showed causal associations with an increased risk of stroke. Genetic predisposition to high apolipoprotein (apo)B to apoA-I ratio was causally associated with an increased risk of IS (OR = 1.12, 95% CI 1.06-1.18, p = 1.1 × 10-4), and a highly suggestive association was found between non-esterified cholesterol in low-density lipoprotein (LDL) and increased risk of atherothrombotic stroke (LAS) (OR = 1.35, 95% CI 1.10-1.66; p = 4.0 × 10-3). Low cholesterol in small and medium LDL was suggestively associated with poor LTO. CONCLUSIONS: Our results support that low medium HDL concentration was causally associated with an increased stroke risk, while high levels of non-esterified cholesterol in LDL were suggestively associated with an increased risk of LAS and with a better LTO.

Spatiotemporal association between air pollution and stroke mortality in South Korea.

BACKGROUND: Air pollutant concentrations in South Korea vary greatly by region and time. To assess temporal and spatial associations of stroke subtypes with long-term air pollution effects on stroke mortality, we studied ischemic stroke (IS), intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH). METHODS: This was an observational study conducted in South Korea from 2001-2018. Concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter ≤10 µm in diameter (PM10) were determined from 332 stations. Average air pollutant concentrations in each district were determined by distance-weighted linear interpolation. The nationwide stroke mortality rates in 249 districts were obtained from the Korean Statistical Information Service. Time intervals were divided into three consecutive 6-year periods: 2001-2006, 2007-2012, and 2013-2018. RESULTS: The concentrations of air pollutants gradually decreased from 2001-2018, along with decreases in IS and ICH mortality rates. However, mortality rates associated with SAH remained constant. From 2001-2006, NO2 (adjusted odds ratio [aOR]:1.13, 95% confidence interval: 1.08-1.19), SO2 (aOR: 1.10, 1.07-1.13), and PM10 (aOR: 1.12, 1.06-1.18) concentrations were associated with IS mortality, and SO2 (aOR: 1.07, 1.02-1.13) and PM10 (aOR:1.11,1.06-1.22) concentrations were associated with SAH-associated mortality. Air pollution was no longer associated with stroke mortality from 2007 onward, as the air pollution concentration continued to decline. Throughout the entire 18-year period, ICH-associated mortality was not associated with air pollution. CONCLUSIONS: Considering temporal and spatial trends, high concentrations of air pollutants were most likely to be associated with IS mortality. Our results strengthen the existing evidence of the deleterious effects of air pollution on IS mortality.

Corrigendum: Ischemic and haemorrhagic stroke risk estimation using a machine-learning-based retinal image analysis.

[This corrects the article DOI: 10.3389/fneur.2022.916966.].

Predictors of congruency between clinical and radiographic Oxfordshire Community Stroke Project Classification subtypes.

BACKGROUND: The Oxfordshire Community Stroke Project (OCSP) classification has been widely used to assess ischemic stroke patients based on clinical characteristics alone. However, the correlation between the clinical presentation evaluated using OCSP and imaging findings is yet to be determined. Our study aimed to describe the baseline characteristics of the OCSP subtypes of patients admitted with ischemic stroke and evaluate the predictors of the relationship between clinical and neuroimaging findings. METHODS: Patients with a confirmed diagnosis of ischemic stroke admitted to a comprehensive stroke center in Brazil between February 2015 and October 2017 were eligible for the study. All participants underwent computed tomography (CT) at admission and follow-up neuroimaging within seven days, per the institutional protocol. Trained staff classified patients according to the OCSP at hospital admission. The radiographic OCSP classification was retrospectively assessed based on the last follow-up neuroimaging by investigators unaware of the clinical classification. RESULTS: The overall agreement rates ranged from 65.5% to 88.7%. Lower NIHSS scores, absent hyperdense MCA sign, higher ASPECTS, and absent brainstem symptoms were related to a higher risk of misclassification. Treatment with intravenous tPA was associated with reclassification in patients with total anterior circulation syndrome. For predicting radiographic posterior circulation involvement, vertigo (OR 2.9, 95% CI 1.7-5.1, p < 0.001) and brainstem symptoms (OR 35, 95% CI 20.5-60.2, p < 0.001) were directly associated with correct classification, but motor and higher cerebral function were not correlated. CONCLUSION: The clinical OCSP classification presented good congruency rates with the neuroimaging findings. However, patients with lacunar syndromes are often misclassified when radiological criteria are considered.

Outcome of COVID-19-Associated Acute Stroke: A Study from South India.

Background and Objective: Coronavirus 2019 (COVID-19) infection is prevalent worldwide. COVID-19 infection can lead to various neurological disorders including acute stroke. We investigated the functional outcome and its determinants among our patients with acute stroke associated with COVID-19 infection in the present setup. Materials and Methods: This study is a prospective study in which we recruited acute stroke patients with COVID-19 positivity. Data on duration of COVID-19 symptoms and type of acute stroke were recorded. All patients underwent stroke subtype workup and measurement of D-dimer, C-reactive protein (CRP), lactate-dehydrogenase (LDH), procalcitonin, interleukin-6, and ferritin levels. Poor functional outcome was defined by modified Rankin score (mRS) ≥3 at 90 days. Results: During the study period, 610 patients were admitted for acute stroke, of whom 110 (18%) tested positive for COVID-19 infection. Majority (72.7%) were men with a mean age of 56.5 years and mean duration of COVID-19 symptoms for 6.9 days. Acute ischemic and hemorrhagic strokes were observed in 85.5% and 14.5% patients, respectively. Poor outcome was observed in 52.7%, including in-hospital mortality in 24.5% patients. COVID-19 symptoms ≤5 days (odds ratio [OR]: 1.41, 95% confidence interval [CI]: 1.20-2.99), CRP positivity (OR: 1.97, 95% CI: 1.41-4.87), elevated levels of D-dimer (OR: 2.11, 95% CI: 1.51-5.61), interleukin-6 (OR: 1.92, 95% CI: 1.04-4.74), and serum ferritin (OR: 2.4, 95% CI: 1.02-6.07), and cycle threshold (Ct) value ≤25 (OR: 8.8, 95% CI: 6.52-12.21) were independent predictors of poor outcome. Conclusion: Poor outcomes were relatively higher among acute stroke patients with concomitant COVID-19 infection. In the present study, we established the independent predictors of poor outcome to be onset of COVID-19 symptoms (<5 days) and elevated levels of CRP, D-dimer, interleukin-6, ferritin, and Ct value ≤25 in acute stroke.

Gut microbiome and risk of ischaemic stroke: a comprehensive Mendelian randomization study.

AIMS: Increasing evidence implicates the microbiome as a susceptibility factor for ischaemic stroke (IS). Interpretation of this evidence is difficult, for the composition of the microbiome is influenced by various factors and might affect differently in IS subtypes. We aim to determine if the specific gut microbiome is causally associated with IS subtypes and suggest potential approaches for stroke prevention. METHODS AND RESULTS: We conducted a two-sample Mendelian randomization (MR) analysis to test the causal relationship between gut microbiome and IS subtypes. For exposure data, we extracted genetic variants associated with 194 bacterial traits from MiBioGen consortium (n = 18 340). For outcomes, we selected three IS subtypes including cardioembolic stroke (CES, n = 410 484), small vessel stroke (SVS, n = 198 048), and large artery stroke (LAS, n = 198 048). Additionally, we performed a sequence of sensitivity analyses to validate preliminary MR results. There were four, three, and four bacteria showing an increased risk for LAS, SVS, and CES, respectively, and there were five, six, and five bacteria leading a decreasing risk for LAS, SVS, and CES, respectively. Amongst these, the genus_Intestinimonas showed negative associations with LAS [odds ratio (OR) = 0.77, 95% confidence interval (CI) (0.61-0.98)] and SVS (0.85, 0.73-0.98). The genus_LachnospiraceaeNK4A136group was genetically associated with decreased risk of both SVS (0.81, 0.66-0.99) and CES (0.75, 0.60-0.94). CONCLUSION: The study revealed the causal effect of the abundance of specific bacterial features on the risk of IS subtypes. Notably, genus_Intestinimonas and genus_LachnospiraceaeNK4A136group displayed significant protection against more than one IS subtype, further suggesting potential applications of targeted probiotics in IS prevention.

This Mendelian randomization study supports the causal effects of the gut microbiome on ischaemic stroke. Several types of intestinal bacterial traits were detected to potentially increase or decrease the risk of incident ischaemic stroke. These may have prospects for the prevention of different ischaemic stroke subtypes. In addition, the clinical benefits of the gut microbiome should be further evaluated in future large-scale people research.

The Association Between Adult Height and Stroke Incidence in Japanese Men and Women: A Population-based Case-Control Study.

BACKGROUND: No studies have examined the associations between adult height and ischemic stroke subtypes. METHODS: We conducted a population-based case-control study that included 2,451 thrombotic and 687 embolic stroke cases, as well as 1,623 intracerebral and 768 subarachnoid hemorrhage cases without history of stroke aged 40-79 years, and the same number of sex- and age-matched controls. Cases and controls were grouped according to the quintile cut-off values of height in controls, and the third quintile, which was approximately the average height group, was used as the reference group. Height divided by one standard deviation of height in controls was also examined as a continuous variable. The analyses were carried out separately for participants aged 40-59 years and 60-79 years. RESULTS: In both younger and older men, height was linearly inversely associated with total and thrombotic strokes, and the shortest quintile compared to the reference group was associated with increased risks of these strokes. Although height was linearly inversely associated with embolic stroke and intracerebral hemorrhage in younger men, the shortest quintile did not show increased risks of these strokes. Height did not seem to be associated with total stroke and any stroke subtypes in younger women. In contrast, the tallest quintile was significantly associated with increased risks of total stroke and intracerebral hemorrhage, and height tended to be positively associated with these strokes in older women. CONCLUSION: We reported the associations between adult height and ischemic stroke subtypes for the first time, which differed according to sex and age group.