Sex differences in outcome after carotid revascularization in symptomatic and asymptomatic carotid artery stenosis.

OBJECTIVE: Sex differences regarding the safety and efficacy of carotid revascularization in carotid artery stenosis have been addressed in several studies with conflicting results. Moreover, women are underrepresented in clinical trials, leading to limited conclusions regarding the safety and efficacy of acute stroke treatments. METHODS: A systematic review and meta-analysis was performed by literature search including four databases from January 1985 to December 2021. Sex differences in the efficacy and safety of revascularization procedures, including carotid endarterectomy (CEA) and carotid artery stenting (CAS), for symptomatic and asymptomatic carotid artery stenoses were analyzed. RESULTS: Regarding CEA in symptomatic carotid artery stenosis, the stroke risk in men (3.6%) and women (3.9%) based on 99,495 patients (30 studies) did not differ (P = .16). There was also no difference in the stroke risk by different time frames up to 10 years. Compared with men, women treated with CEA had a significantly higher stroke or death rate at 4 months (2 studies, 2565 patients; 7.2% vs 5.0%; odds ratio [OR], 1.49; 95% confidence interval [CI], 1.04-2.12; I2 = 0%; P = .03), and a significantly higher rate of restenosis (1 study, 615; 17.2% vs 6.7%; OR, 2.81; 95% CI, 1.66-4.75; P = .0001). For CAS in symptomatic artery stenosis, data showed a non-significant tendency toward higher peri-procedural stroke in women, whereas for asymptomatic carotid artery stenosis, data based on 332,344 patients showed that women (compared with men) after CEA had similar rates of stroke, stroke or death, and the composite outcome stroke/death/myocardial infarction. The rate of restenosis at 1 year was significantly higher in women compared with men (1 study, 372 patients; 10.8% vs 3.2%; OR, 3.71; 95% CI, 1.49-9.2; P = .005). Furthermore, CAS in asymptomatic patients was associated with low risk of a postprocedural stroke in both sexes, but a significantly higher risk of in-hospital myocardial infarction in women than men (8445 patients, 1.2% vs 0.6%; OR, 2.01; 95% CI, 1.23-3.28; I2 = 0%; P = .005). CONCLUSIONS: A few sex-differences in short-term outcomes after carotid revascularization for symptomatic and asymptomatic carotid artery stenosis were found, although there were no significant differences in the overall stroke. This indicates a need for larger multicenter prospective studies to evaluate these sex-specific differences. More women, including those aged over 80 years, need to be enrolled in randomized controlled trials, to better understand if sex differences exist and to tailor carotid revascularization accordingly.

Mechanical thrombectomy in young patients with large vessel occlusion-related ischemic stroke: Data from the Italian Registry of Endovascular Treatment in Acute Stroke.

BACKGROUND AND PURPOSE: The weight of outcome predictors in acute ischemic stroke (AIS) patients older than 60 years is not necessarily mirrored in the younger population, posing the question of whether outcome determinants specific for the latter might vary. Very few data are available on predictors of outcome in young AIS patients receiving endovascular treatment (EVT). METHODS: We analyzed data for patients aged between 16 and 55 years from the Italian Registry of Endovascular Treatment in Acute Stroke. We divided our population into patients <45 years old and patients aged between 45 and 55 years. After testing the differences between groups in terms of 90-day modified Rankin Scale (mRS) 0-2, mortality, and symptomatic intracranial hemorrhage, we looked for predictors of poor outcome (mRS 3-6), death, and symptomatic intracerebral hemorrhage in the two groups. RESULTS: A total of 438 patients younger than 45 years and 817 aged 45-55 years were included; 284 (34.8%) patients aged 45-55 years and 112 (25.6%) patients younger than 45 years old showed poor 90-day functional outcome (p = 0.001). Predictors of poor outcome in the older group were baseline National Institutes of Health Stroke Scale (NIHSS; p < 0.001), diabetes (p = 0.027), poor collateral status (p = 0.036), and groin puncture-to-recanalization time (p = 0.010), whereas Thrombolysis in Cerebral Infarction (TICI) 2b-3 had an inverse association (p < 0.001). Predictors of poor outcome in patients younger than 45 years were baseline NIHSS (p < 0.001) and groin puncture-to-recanalization time (p = 0.015), whereas an inverse association was found for baseline Alberta Stroke Program Early CT Score (p = 0.010) and TICI 2b-3 (p < 0.001). CONCLUSIONS: Approximately one third of young adults treated with EVT do not reach a good functional outcome. Fast and successful recanalization, rather than common risk factors, has a major role in determining clinical outcome.

A transient magnetic resonance spectroscopy peri-ischemic peak: a possible radiological biomarker of post-stroke neurogenesis.

BACKGROUND AND AIMS: In adult human brain, neurogenesis seems to persist throughout life and ischemic stroke was proved to stimulate this process. Using magnetic resonance spectroscopy (MRS), a 1.28-ppm peak, putative biomarker of neural progenitor cells (NPCs), was identified both in vitro and in vivo, i.e., in normal rat and healthy human brain. The aim of our study was to identify a 1.28-ppm peak in adult human ischemic brain by using 3.0 T multivoxel MRS. METHODS: We studied 10 patients, six males, and four females, with a mean (± SD) age of 59.3 (± 17.3), at three different time points from ischemic stroke onset (T0: < 5 days; T14: 14 ± 2 days; T30: 30 ± 2 days). RESULTS: In all patients except one, a 1.28-ppm peak at T14 was detected at the ischemic boundary (all p values < 0.05). MRS performed on six voluntary age-matched healthy subjects did not detect any 1.28-ppm peak. CONCLUSIONS: The nature of this 1.28-pm peak is uncertain; however, our data support the hypothesis that it might represent a marker of NPCs in post-stroke human brain.

No-reflow phenomenon in acute ischemic stroke: an angiographic evaluation.

BACKGROUND: Futile recanalization (FR) is de fined as a poor 90-day outcome or lack of neurological improvement at 24 h despite successful recanalization in acute ischemic stroke (AIS) with large vessel occlusion (LVO) treated by mechanical throbectomy (MT). The No-reflow phenomenon (NRP) could be a possible cause of FR, but its evidence in AIS patients is scarce. METHODS: We retrospectively analyzed 185 digital subtraction angiographies (DSA) of AIS patients with anterior circulation LVO after endovascular treatment. To better define NRP, we designed a score called the modified capillary index score (mCIS). The score is obtained by dividing the middle cerebral artery territory in three segments. For each segment, we gave 2 points if the capillary blush was present without any delay, 1 if delayed, and 0 if absent. The primary endpoint was to use mCIS to identify NRP on post-interventional DSA and to test whether this marker may predict FR and failure of early neurological improvement (fENI). The secondary endpoint was to search for a correlation between NRP, lesion volume, and hemorrhagic transformation. We used the ROC curve to define mCIS ≤ 3 as the cut-off and marker of NRP. RESULTS: NRP was present in 35.1% of patients. NRP predicted fENI at 24 h (aOR 2.825, 95% CI 1.265-6.308, P = 0.011) and at 7 days (aOR 2.191, 95% CI 1.008-4.762, P = 0.048), but not 90-day FR. Moreover, NRP predicted hemorrhagic transformation (aOR 2.444, 95% CI 1.266-4.717, P = 0.008). CONCLUSIONS: The modified capillary index score (mCIS) seems useful in identifying NRP in AIS. In addition, mCIS was able to predict NRP that correlated with early clinical outcome and hemorrhagic transformation of the ischemic lesion. An external validation of the score is warranted.

Hemorrhagic risk after intravenous thrombolysis for ischemic stroke in patients with cerebral microbleeds and white matter disease.

OBJECTIVES: Aim of this study was to evaluate the association between cerebral microbleeds (CMBs) and white matter disease (WMD) with intracerebral hemorrhage (ICH) after intravenous thrombolysis (IVT) with rt-PA. We also evaluated whether CMBs characteristics and WMD burden correlate with symptomatic ICH and outcome. METHODS: We included acute ischemic stroke (AIS) patients treated with IVT. The number and location of CMBs as well as severity of WMD were rated analyzing pre- or post-treatment MRI. Multivariable regression analysis was used to determine the impact of CMB and WMD on ICH subgroups and outcome measures. RESULTS: 434 patients were included. CMBs were detected in 23.3% of them. ICH occurred in 34.7% of patients with CMBs. Independent predictors of parenchymal hemorrhage were the presence of CMBs (OR 2.724, 95% CI 1.360-5.464, p = 0.005) as well as cortical-subcortical stroke (OR 3.629, 95% CI 1.841-7.151, p < 0.001) and atherothrombotic stroke subtype (OR 3.381, 95% CI 1.335-8.566, p = 0.010). Either the presence, or number, and location of CMBs, as well as WMD, was not independently associated with the development of SICH. No independent association between the presence, number, or location of CMBs or WMD and outcome measures was observed. CONCLUSIONS: The results of our study suggest that the exclusion of eligible candidates to administration of IV rt-PA only on the basis of CMBs presence is not justified. The clinical decision should be weighed with a case-by-case approach. Additional data are needed to evaluate the benefit-risk profile of rt-PA in patients carrying numerous microbleeds.

Copeptin Kinetics in Acute Ischemic Stroke May Differ According to Revascularization Strategies: Pilot Data.

Background and Purpose- Prognostic value of copeptin in acute ischemic stroke has been widely reported. This study aimed to evaluate copeptin temporal profile according to revascularization strategies and the development of brain edema and hemorrhagic transformation. Methods- Plasma copeptin and brain edema and hemorrhagic transformation assessed by computed tomography/magnetic resonance imaging were evaluated upon admission (T0), at 24 hours (T1), and between the third and fifth day of hospitalization (T2) in 34 acute ischemic stroke patients. Results- Median copeptin concentration was 50.71 pmol/L at T0, 18.31 pmol/L at T1, and 10.92 pmol/L at T2. Copeptin at T1 was higher in patients with medium/severe brain edema at T2 (32.25 versus 13.67 pmol/L; P=0.038) and hemorrhagic transformation at T1 (93.10 versus 13.67 pmol/L; P<0.003) and T2 (85.70 versus 14.45 pmol/L; P=0.024). Copeptin level drop (CopΔT1-T0) was significantly steeper in patients receiving revascularization, particularly in those undergoing combined therapy (-129.34 versus -5.43 pmol/L; P=0.038). ΔT1-T0 also correlated with Thrombolysis in Cerebral Infarction score (P<0.001). Conclusions- Copeptin resulted associated with brain edema and hemorrhagic transformation in acute ischemic stroke, and its drop at 24 hours may mirror effective brain vessel recanalization.

Impact of Transcranial Doppler Ultrasound on Logistics and Outcomes in Stroke Thrombolysis: Results From the SITS-ISTR.

BACKGROUND AND PURPOSE: Diagnostic transcranial Doppler ultrasound (TCD) is commonly used in patients with acute stroke before or during treatment with intravenous thrombolysis (IVT). We aimed to assess how much TCD delays IVT initiation and whether TCD influences outcomes. METHODS: We analyzed data from the SITS-ISTR (Safe Implementation of Thrombolysis in Stroke-International Stroke Thrombolysis Register) collected from December 2002 to December 2011. Outcomes were door-to-needle time, symptomatic intracerebral hemorrhage, functional outcome per the modified Rankin Scale, and mortality at 3 months. RESULTS: In hospitals performing any TCD pre-IVT, 1701 of 11 265 patients (15%) had TCD before IVT initiation. Door-to-needle time was higher in patients with pre-IVT TCD (74 versus 60 minutes; P<0.001). At hospitals performing any TCD during IVT infusion, of 9044 patients with IVT, 747 were examined with TCD during IVT. No treatment delay was seen with TCD during IVT. After multivariate adjustment, TCD during IVT was independently associated with modestly increased excellent functional outcome (modified Rankin Scale, 0-1; adjusted odds ratio, 1.28; 95% confidence interval, 1.06-1.55; P=0.012) and lower mortality (adjusted odds ratio, 0.73; 95% confidence interval, 0.55-0.95; P=0.022). CONCLUSIONS: We recommend that TCD, if performed, should be done during IVT infusion, to avoid treatment delay. The association of hyperacute TCD with beneficial outcomes suggests potential impact on patient management, which warrants further study.

Oxidative Stress Biomarkers of Brain Damage: Hyperacute Plasma F2-Isoprostane Predicts Infarct Growth in Stroke.

BACKGROUND AND PURPOSE: Oxidative stress is an early response to cerebral ischemia and is likely to play an important role in the pathogenesis of cerebral ischemic injury. We sought to evaluate whether hyperacute plasma concentrations of biomarkers of oxidative stress, inflammation, and tissue damage predict infarct growth (IG). METHODS: We prospectively measured plasma F2-isoprostane (F2-isoP), urinary 8-oxo-7,8-dihydro-2'-deoxyguoanosine, plasma oxygen radical absorbance capacity assay, high sensitivity C reactive protein, and matrix metalloproteinase 2 and 9 in consecutive patients with acute ischemic stroke presenting within 9 hours of symptom onset. Patients with baseline diffusion-weighted magnetic resonance imaging and follow-up diffusion-weighted imaging or computed tomographic scan were included to evaluate the final infarct volume. Baseline diffusion-weighted imaging volume and final infarct volume were analyzed using semiautomated volumetric method. IG volume was defined as the difference between final infarct volume and baseline diffusion-weighted imaging volume. RESULTS: A total of 220 acute ischemic stroke subjects were included in the final analysis. One hundred seventy of these had IG. Baseline F2-isoP significantly correlated with IG volume (Spearman ρ=0.20; P=0.005) and final infarct volume (Spearman ρ=0.19; P=0.009). In a multivariate binary logistic regression model, baseline F2-isoP emerged as an independent predictor of the occurrence of IG (odds ratio, 2.57; 95% confidence interval, 1.37-4.83; P=0.007). In a multivariate linear regression model, baseline F2-isoP was independently associated with IG volume (B, 0.38; 95% confidence interval, 0.04-0.72; P=0.03). CONCLUSIONS: Elevated hyperacute plasma F2-isoP concentrations independently predict the occurrence of IG and IG volume in patients with acute ischemic stroke. If validated in future studies, measuring plasma F2-isoP might be helpful in the acute setting to stratify patients with acute ischemic stroke for relative severity of ischemic injury and expected progression.

Integrative Mouse and Human Studies Implicate ANGPT1 and ZBTB7C as Susceptibility Genes to Ischemic Injury.

BACKGROUND AND PURPOSE: The extent of ischemic injury in response to cerebral ischemia is known to be affected by native vasculature. However, the nonvascular and dynamic vascular responses and their genetic basis are not well understood. METHODS: We performed a genome-wide association study in 235 mice from 33 inbred strains using the middle cerebral artery occlusion model. Population structure and genetic relatedness were accounted for using the efficient mixed-model association method. Human orthologs to the genes associated with the significant and suggestive single-nucleotide polymorphisms from the mouse strain survey were examined in patients with M1 occlusions admitted with signs and symptoms of acute ischemic stroke. RESULTS: We identified 4 genome-wide significant and suggestive single-nucleotide polymorphisms to be associated with infarct volume in mice (rs3694965, P=2.17×10(-7); rs31924033, P=5.61×10(-6); rs32249495, P=2.08×10(-7); and rs3677406, P=9.56×10(-6)). rs32249495, which corresponds to angiopoietin-1 (ANGPT1), was also significant in the recessive model in humans, whereas rs1944577, which corresponds to ZBTB7C, was nominally significant in both the additive and dominant genetic models in humans. ZBTB7C was shown to be upregulated in endothelial cells using both in vitro and in vivo models of ischemia. CONCLUSIONS: Genetic variations of ANGPT1 and ZBTB7C are associated with increased infarct size in both mice and humans. ZBTB7C may modulate the ischemic response via neuronal apoptosis and dynamic collateralization and, in addition to ANGPT1, may serve as potential novel targets for treatments of cerebral ischemia.

Fluid-attenuated inversion recovery hyperintensity correlates with matrix metalloproteinase-9 level and hemorrhagic transformation in acute ischemic stroke.

BACKGROUND AND PURPOSE: Matrix metalloproteinase-9 (MMP-9) is elevated in patients with acute stroke who later develop hemorrhagic transformation (HT). It is controversial whether early fluid-attenuated inversion recovery (FLAIR) hyperintensity on brain MRI predicts hemorrhagic transformation (HT). We assessed whether FLAIR hyperintensity was associated with MMP-9 and HT. METHODS: We analyzed a prospectively collected cohort of acute stroke subjects with acute brain MRI images and MMP-9 values within the first 12 hours after stroke onset. FLAIR hyperintensity was measured using a signal intensity ratio between the stroke lesion and corresponding normal contralateral hemisphere. MMP-9 was measured using enzyme-linked immunosorbent assay. The relationships between FLAIR ratio (FR), MMP-9, and HT were evaluated. RESULTS: A total of 180 subjects were available for analysis. Patients were imaged with brain MRI at 5.6±4.3 hours from last seen well time. MMP-9 blood samples were drawn within 7.7±4.0 hours from last seen well time. The time to MRI (r=0.17, P=0.027) and MMP-9 level (r=0.29, P<0.001) were each associated with FR. The association between MMP-9 and FR remained significant after multivariable adjustment (P<0.001). FR was also associated with HT and symptomatic hemorrhage (P=0.012). CONCLUSIONS: FR correlates with both MMP-9 level and risk of hemorrhage. FLAIR changes in the acute phase of stroke may predict hemorrhagic transformation, possibly as a reflection of altered blood-brain barrier integrity.

Within-day and weekly variations of thrombolysis in acute ischemic stroke: results from safe implementation of treatments in stroke-international stroke thrombolysis register.

BACKGROUND AND PURPOSE: Temporal variations of thrombolysis delivery and their influence on outcome have been reported with controversial results. In this large cohort study, we evaluated whether thrombolytic treatment has a within-day and weekly variability corresponding to circadian and weekly patterns of ischemic stroke onset, and whether these have impact on clinical outcome. METHODS: We retrospectively analyzed patients with acute ischemic stroke receiving intravenous alteplase, prospectively included in the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register. Patients were grouped by treatment on day hours (08:00-19:59) or night hours (20:00-07:59) and treatment on weekdays and weekends. For each subgroup, we analyzed frequency of thrombolytic treatments, time intervals, and outcomes (3-month modified Rankin Scale score 0-2 as good functional outcome, mortality, symptomatic intracerebral hemorrhage). RESULTS: We included 21 513 patients. Considering the mean expected number of patients treated per hour (0.4) and per day of the week (9.8), if no temporal variations were present, patients were significantly treated more during day hours and weekdays (P<0.0001). Median door-to-needle and onset-to-treatment times were longer for patients treated during night hours and on weekends (P<0.01). After adjustment for confounding variables, treatment during day hours was an independent predictor of good functional outcome (odds ratio, 1.12; 95% confidence interval, 1.04-1.21; P=0.004), and patients treated during weekdays were at risk of higher mortality (odds ratio, 1.15; 95% confidence interval, 1.04-1.28; P=0.008). CONCLUSIONS: Frequency of thrombolytic treatment seems to follow the same circadian pattern of stroke incidence, whereas its correspondence to a weekly pattern is less clear. Time of treatment is an independent predictor of outcome.

White matter hyperintensity volume correlates with matrix metalloproteinase-2 in acute ischemic stroke.

BACKGROUND: White matter hyperintensity (WMH), a common radiographic finding associated with stroke risk and outcome, has been linked to matrix metalloproteinase (MMP) activity and increased levels of oxidative stress in nonstroke populations. We sought to determine whether WMH severity is associated with plasma levels of MMPs and oxidative stress (F2-isoprostane) in subjects with acute ischemic stroke (AIS). METHODS: We measured plasma biomarker levels at baseline and 48 hours in consecutive AIS subjects. White matter hyperintensity volume (WMHv) was quantified on admission magnetic resonance imaging using a validated semiautomated protocol, and Spearman correlation coefficients were derived for all measured biomarkers. RESULTS: We enrolled 405 AIS subjects (mean age 70±15 years; 58% male; median WMHv 3.4 cm3, interquartile range 1.4-9.5). WMHv and age were strongly correlated (ρ=.57, P<.0001). WMHv and MMP-2 levels were correlated at baseline (ρ=.23, P<.0001) and at 48 hours poststroke (ρ=.19, P=.002). In multivariate analysis, 48-hour MMP-2 levels were independently associated with WMHv (ß=.12, P=.04). MMP-9 and F2-isioprostane levels did not correlate with WMHv. CONCLUSIONS: In AIS patients, MMP-2 levels are associated with the pre-existing burden of WMH. If validated, these findings may further elucidate the role of MMP-2 in pathophysiology of chronic cerebrovascular injury, such as WMH, and in brain susceptibility to acute ischemia.

Can Repetitive Transcranial Magnetic Stimulation (rTMS) Promote Neurogenesis and Axonogenesis in Subacute Human Ischemic Stroke?

BACKGROUND: Ischemic stroke may trigger neuroplastic changes via proliferation, migration towards the lesion, and differentiation of neuroprogenitor cells into mature neurons. Repetitive Transcranial Magnetic Stimulation (rTMS) may promote brain plasticity. This study aimed to assess rTMS's effect on post-stroke endogenous neuroplasticity by dosing plasma miRs 17~92, Netrin-1, Sema3A, and BDNF. METHODS: In this case-controlled study, we randomized 19 ischemic stroke patients within five days from symptoms onset (T0) to neuronavigated-rTMS or sham stimulation. Stimulation was applied on the stroke hemisphere daily between the 7th and 14th day from stroke onset. Blood samples were collected at T0, before the first rTMS section (T7), and at the end of the last rTMS session (T14). Five healthy controls were also enrolled in this study. RESULTS: Of 19 patients, 10 received rTMS and 9 sham stimulation. Compared with the sham group, in the rTMS group, plasma levels of miRs17~92 and Ntn-1 significantly increased whereas Sema3A levels tended to decrease. In multivariate linear regression analyses, rTMS was independently related to Ntn-1 and miR-25 levels at T14. CONCLUSIONS: We found an association between rTMS and neurogenesis/axonogenesis biomarker enhancement. Our preliminary data suggest that rTMS may positively interfere with natural endogenous plasticity phenomena of the post-ischemic human brain.

Does sex influence the response to intravenous thrombolysis in ischemic stroke?: answers from safe implementation of treatments in Stroke-International Stroke Thrombolysis Register.

BACKGROUND AND PURPOSE: Women are more likely to have a worse outcome after an acute stroke than men. Some studies have suggested that women also benefit less from intravenous thrombolysis after an acute ischemic stroke, but others found no sex differences in safety and efficacy. We aimed to evaluate differences in 3-month outcome between sexes in intravenous tissue-type plasminogen activator-treated patients registered in the Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register. METHODS: A total of 45 079 patients treated with intravenous alteplase were recorded from 2002 to 2011. Main outcome measures were symptomatic intracerebral hemorrhage, functional independence (modified Rankin Scale score, 0-2), and mortality at 3 months. RESULTS: Among 25 777 (57.2%) men and 19 302 (42.8%) women, we found no difference in the rate of symptomatic intracerebral hemorrhage (P=0.13), a significantly higher likelihood of functional independence at 3 months in men (P<0.0001) and a higher mortality in women when compared with men (P<0.00001). After adjustment for confounding variables, we did not observe any difference between sexes in functional outcome (odds ratio, 1.03; 95% confidence interval, 0.97-1.09; P=0.39), whereas male sex was related to a higher risk of mortality (odds ratio, 1.19; 95% confidence interval, 1.10-1.29; P=0.00003) and symptomatic intracerebral hemorrhage (odds ratio, 1.25, 95% confidence interval, 1.04-1.51; P=0.02). CONCLUSIONS: Data from Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register suggest that intravenous thrombolysis may modify the observed survival and recovery advantage for men expected in the natural course of an ischemic stroke, with a possible larger beneficial treatment effect in women when compared with men.

Tissue factor as a potential coagulative/vascular marker in relapsing-remitting multiple sclerosis.

Objectives: Recent studies supported coagulation involvement in multiple sclerosis, an inflammatory-demyelinating and degenerative disease of the central nervous system. The main objectives of this observational study were to identify the most specific pro-coagulative/vascular factors for multiple sclerosis pathogenesis and to correlate them with brain hemodynamic abnormalities. Methods: We compared i) serum/plasma levels of complement(C)/coagulation/vascular factors, viral/microbiological assays, fat-soluble vitamins and lymphocyte count among people with multiple sclerosis sampled in a clinical remission (n=30; 23F/7M, 40 ± 8.14 years) or a relapse (n=30; 24F/6M, age 41 ± 10.74 years) and age/sex-matched controls (n=30; 23F/7M, 40 ± 8.38 years); ii) brain hemodynamic metrics at dynamic susceptibility contrast-enhanced 3T-MRI during relapse and remission, and iii) laboratory data with MRI perfusion metrics and clinical features of people with multiple sclerosis. Two models by Partial Least Squares Discriminant Analysis were performed using two groups as input: (1) multiple sclerosis vs. controls, and (2) relapsing vs. remitting multiple sclerosis. Results: Compared to controls, multiple sclerosis patients had a higher Body-Mass-Index, Protein-C and activated-C9; and a lower activated-C4. Levels of Tissue-Factor, Tie-2 and P-Selectin/CD62P were lower in relapse compared to remission and HC, whereas Angiopoietin-I was higher in relapsing vs. remitting multiple sclerosis. A lower number of total lymphocytes was found in relapsing multiple sclerosis vs. remitting multiple sclerosis and controls. Cerebral-Blood-Volume was lower in normal-appearing white matter and left caudatum while Cerebral-Blood-Flow was inferior in bilateral putamen in relapsing versus remitting multiple sclerosis. The mean-transit-time of gadolinium-enhancing lesions negatively correlated with Tissue-Factor. The top-5 discriminating variables for model (1) were: EBV-EBNA-1 IgG, Body-Mass-Index, Protein-C, activated-C4 and Tissue-Factor whereas for model (2) were: Tissue-Factor, Angiopoietin-I, MCHC, Vitamin A and T-CD3. Conclusion: Tissue-factor was one of the top-5 variables in the models discriminating either multiple sclerosis from controls or multiple sclerosis relapse from remission and correlated with mean-transit-time of gadolinium-enhancing lesions. Tissue-factor appears a promising pro-coagulative/vascular biomarker and a possible therapeutic target in relapsing-remitting multiple sclerosis. Clinical trial registration: ClinicalTrials.gov, identifier NCT04380220.

Aspirin for Primary Stroke Prevention; Evidence for a Differential Effect in Men and Women.

Background: The use of aspirin for primary prevention of cardiovascular events in men and women remains controversial. Our study aimed to investigate the role of aspirin in primary stroke prevention in men and women and the effect of aspirin on risk of ischemic stroke in patients with covert cerebral small vessel disease (ccSVD). Methods: We performed systematic searches of the PubMed, and Cochrane Library databases, covering the period from the inception of each database to May 2021. The incidence of any ischemic stroke (IS) or hemorrhagic stroke (HS) was the main outcome. The incidence of stroke overall, both ischemic (IS) and hemorrhagic (HS), was the main outcome. Results: From 531 abstracts, 11 randomized control trials which assessed primary prevention of cardiovascular events in men and women were included. Only one study assessed the risk of aspirin in people with ccSVD. In women, there was significant decrease in the risk of stroke (OR 0.85 [95% CI 0.73, 0.99], p = 0.03) and IS (OR 0.76 [0.63, 0.93], p = 0.008) with aspirin compared to placebo while no increase in the risk of HS was found (OR 1.78 [0.61, 5.19], p = 0.29). In men, aspirin did not affect the risk of stroke (OR 1.13 [0.97, 1.31], p = 0.12) and IS (OR 0.94 [0.67, 1.32], p = 0.72) but increased the risk of HS with borderline statistical significance (OR 1.99 [0.99, 4.03], p = 0.05) compared to placebo. Aspirin significantly increased major bleedings in both sexes (p < 0.05). We found no evidence to support the use of aspirin in patients with ccSVD. Conclusion: Our meta-analysis suggests aspirin is effective in primary prevention of stroke and IS in women with no clear increased risk of HS. However, it was associated with an overall increased risk of bleeding. Aspirin is not recommended in ccSVD.

Evidence of SARS-CoV-2 spike protein on retrieved thrombi from COVID-19 patients.

The pathophysiology of COVID-19-associated coagulopathy is complex and not fully understood. SARS-CoV-2 spike protein (SP) may activate platelets and interact with fibrin(ogen). We aimed to investigate whether isolated SP can be present in clots retrieved in COVID-19 patients with acute ischemic stroke (by mechanical thrombectomy) and myocardial infarction. In this pilot study, we could detect SP, but not nucleocapsid protein, on platelets of COVID-19 patients' thrombi. In addition, in all three COVID-19 thrombi analyzed for molecular biology, no SARS-CoV-2 RNA could be detected by real-time polymerase chain reaction. These data could support the hypothesis that free SP, besides the whole virus, may be the trigger of platelet activation and clot formation in COVID-19.

European Stroke Organisation guidelines on stroke in women: Management of menopause, pregnancy and postpartum.

Pregnancy, postpartum and menopause are regarded as periods women are more vulnerable to ischaemic events. There are conflicting results regarding stroke risk and hormone replacement therapy (HRT) during menopause. Stroke in pregnancy is generally increasing with serious consequences for mother and child; therefore, recommendations for acute treatment with intravenous thrombolysis (IVT) and/or mechanical thrombectomy (MT) are needed. The aim of this guideline is to support and guide clinicians in treatment decisions in stroke in women. Following the "Grading of Recommendations and Assessment, Development and Evaluation (GRADE)" approach, the guidelines were developed according to the European Stroke Organisation (ESO) Standard Operating Procedure. Systematic reviews and metanalyses were performed. Based on available evidence, recommendations were provided. Where there was a lack of evidence, an expert consensus statement was given. Low quality of evidence was found to suggest against the use of HRT to reduce the risk of stroke (ischaemic and haemorrhagic) in postmenopausal women. No data was available on the outcome of women with stroke when treated with HRT. No sufficient evidence was found to provide recommendations for treatment with IVT or MT during pregnancy, postpartum and menstruation. The majority of members suggested that pregnant women can be treated with IVT after assessing the benefit/risk profile on an individual basis, all members suggested treatment with IVT during postpartum and menstruation. All members suggested treatment with MT during pregnancy. The guidelines highlight the need to identify evidence for stroke prevention and acute treatment in women in more vulnerable periods of their lifetime to generate reliable data for future guidelines.

SARS-CoV-2 infection predicts larger infarct volume in patients with acute ischemic stroke.

Background and purpose: Acute ischemic stroke (AIS) is a fearful complication of Coronavirus Disease-2019 (COVID-19). Aims of this study were to compare clinical/radiological characteristics, endothelial and coagulation dysfunction between acute ischemic stroke (AIS) patients with and without COVID-19 and to investigate if and how the SARS-CoV-2 spike protein (SP) was implicated in triggering platelet activation. Methods: We enrolled AIS patients with COVID-19 within 12 h from onset and compared them with an age- and sex-matched cohort of AIS controls without COVID-19. Neuroimaging studies were performed within 24 h. Blood samples were collected in a subset of 10 patients. Results: Of 39 AIS patients, 22 had COVID-19 and 17 did not. Admission levels of Factor VIII and von Willebrand factor antigen were significantly higher in COVID-19 patients and positively correlated with the infarct volume. In multivariate linear regression analyses, COVID-19 was an independent predictor of infarct volume (B 20.318, Beta 0.576, 95%CI 6.077-34.559; p = 0.011). SP was found in serum of 2 of the 10 examined COVID-19 patients. Platelets from healthy donors showed a similar degree of procoagulant activation induced by COVID-19 and non-COVID-19 patients' sera. The anti-SP and anti-FcγRIIA blocking antibodies had no effect in modulating platelet activity in both groups. Conclusions: SARS-CoV-2 infection seems to play a major role in endothelium activation and infarct volume extension during AIS.