External validation of the SI2NCAL2C score for outcomes following cerebral venous thrombosis.

OBJECTIVES: Prognostication for cerebral venous thrombosis (CVT) remains difficult. We sought to validate the SI2NCAL2C score in an international cohort. MATERIALS AND METHODS: The SI2NCAL2C score was originally developed to predict poor outcome (modified Rankin Scale (mRS) 3-6) at 6 months, and mortality at 30 days and 1 year using data from the International CVT Consortium. The SI2NCAL2C score uses 9 variables: the absence of any female-sex-specific risk factors, intracerebral hemorrhage, central nervous system infection, focal neurological deficits, coma, age, lower level of hemoglobin, higher level of glucose, and cancer. The ACTION-CVT study was an international retrospective study that enrolled consecutive patients across 27 centers. The poor outcome score was validated using 90-day mRS due to lack of follow-up at the 6-month time-point in the ACTION-CVT cohort. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC) and calibration plots. Missing data were imputed using the additive regression and predictive mean matching methods. Bootstrapping was performed with 1000 iterations. RESULTS: Mortality data were available for 950 patients and poor outcome data were available for 587 of 1,025 patients enrolled in ACTION-CVT. Compared to the International CVT Consortium, the ACTION-CVT cohort was older, less often female, and with milder clinical presentation. Mortality was 2.5% by 30 days and 6.0% by one year. At 90-days, 16.7% had a poor outcome. The SI2NCAL2C score had an AUC of 0.74 [95% CI 0.69-0.79] for 90-day poor outcome, 0.72 [0.60-0.82] for mortality by 30 days, and 0.82 [0.76-0.88] for mortality by one year. CONCLUSIONS: The SI2NCAL2C score had acceptable to good performance in an international external validation cohort. The SI2NCAL2C score warrants additional validation studies in diverse populations and clinical implementation studies.

Endovascular treatment of cerebral sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia.

INTRODUCTION: There is little data on the role of endovascular treatment (EVT) of cerebral venous sinus thrombosis (CVST) due to vaccine-induced immune thrombotic thrombocytopenia (VITT). Here, we describe clinical characteristics and outcomes of CVST-VITT patients who were treated with EVT. PATIENTS AND METHODS: We report data from an international registry of patients who developed CVST within 28 days of SARS-CoV-2 vaccination, reported between 29 March 2021 and 6 March 2023. VITT was defined according to the Pavord criteria. RESULTS: EVT was performed in 18/136 (13%) patients with CVST-VITT (92% aspiration and/or stent retrieval, 8% local thrombolysis). Most common indications were extensive thrombosis and clinical or radiological deterioration. Compared to non-EVT patients, those receiving EVT had a higher median thrombus load (4.5 vs 3). Following EVT, local blood flow was improved in 83% (10/12, 95% confidence interval [CI] 54-96). One (6%) asymptomatic sinus perforation occurred. Eight (44%) patients treated with EVT also underwent decompressive surgery. Mortality was 50% (9/18, 95% CI 29-71) and 88% (8/9, 95% CI 25-66) of surviving EVT patients achieved functional independence with a modified Rankin Scale score of 0-2 at follow-up. In multivariable analysis, EVT was not associated with increased mortality (adjusted odds ratio, 0.66, 95% CI 0.16-2.58). DISCUSSION AND CONCLUSION: We describe the largest cohort of CVST-VITT patients receiving EVT. Half of the patients receiving EVT died during hospital admission, but most survivors achieved functional independence.

Genetic Insights on the Relation of Vascular Risk Factors and Cervical Artery Dissection.

BACKGROUND: The association between vascular risk factors and cervical artery dissections (CeADs), a leading cause of ischemic stroke (IS) in the young, remains controversial. OBJECTIVES: This study aimed to explore the causal relation of vascular risk factors with CeAD risk and recurrence and compare it to their relation with non-CeAD IS. METHODS: This study used 2-sample Mendelian randomization analyses to explore the association of blood pressure (BP), lipid levels, type 2 diabetes, waist-to-hip ratio, smoking, and body mass index with CeAD and non-CeAD IS. To simulate effects of the most frequently used BP-lowering drugs, this study constructed genetic proxies and tested their association with CeAD and non-CeAD IS. In analyses among patients with CeAD, the investigators studied the association between weighted genetic risk scores of vascular risk factors and the risk of multiple or early recurrent dissections. RESULTS: Genetically determined higher systolic BP (OR: 1.51; 95% CI: 1.32-1.72) and diastolic BP (OR: 2.40; 95% CI: 1.92-3.00) increased the risk of CeAD (P < 0.0001). Genetically determined higher body mass index was inconsistently associated with a lower risk of CeAD. Genetic proxies for ß-blocker effects were associated with a lower risk of CeAD (OR: 0.65; 95% CI: 0.50-0.85), whereas calcium-channel blockers were associated with a lower risk of non-CeAD IS (OR: 0.75; 95% CI: 0.63-0.90). Weighted genetic risk scores for systolic BP and diastolic BP were associated with an increased risk of multiple or early recurrent CeAD. CONCLUSIONS: These results are supportive of a causal association between higher BP and increased CeAD risk and recurrence and provide genetic evidence for lower CeAD risk under ß-blockers. This may inform secondary prevention strategies and trial design for CeAD.

Sex differences in cerebral venous sinus thrombosis after adenoviral vaccination against COVID-19.

INTRODUCTION: Cerebral venous sinus thrombosis associated with vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) is a severe disease with high mortality. There are few data on sex differences in CVST-VITT. The aim of our study was to investigate the differences in presentation, treatment, clinical course, complications, and outcome of CVST-VITT between women and men. PATIENTS AND METHODS: We used data from an ongoing international registry on CVST-VITT. VITT was diagnosed according to the Pavord criteria. We compared the characteristics of CVST-VITT in women and men. RESULTS: Of 133 patients with possible, probable, or definite CVST-VITT, 102 (77%) were women. Women were slightly younger [median age 42 (IQR 28-54) vs 45 (28-56)], presented more often with coma (26% vs 10%) and had a lower platelet count at presentation [median (IQR) 50x109/L (28-79) vs 68 (30-125)] than men. The nadir platelet count was lower in women [median (IQR) 34 (19-62) vs 53 (20-92)]. More women received endovascular treatment than men (15% vs 6%). Rates of treatment with intravenous immunoglobulins were similar (63% vs 66%), as were new venous thromboembolic events (14% vs 14%) and major bleeding complications (30% vs 20%). Rates of good functional outcome (modified Rankin Scale 0-2, 42% vs 45%) and in-hospital death (39% vs 41%) did not differ. DISCUSSION AND CONCLUSIONS: Three quarters of CVST-VITT patients in this study were women. Women were more severely affected at presentation, but clinical course and outcome did not differ between women and men. VITT-specific treatments were overall similar, but more women received endovascular treatment.

Cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia in middle-income countries.

BACKGROUND: Adenovirus-based COVID-19 vaccines are extensively used in low- and middle-income countries (LMICs). Remarkably, cases of cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) have rarely been reported from LMICs. AIMS: We studied the frequency, manifestations, treatment, and outcomes of CVST-VITT in LMICs. METHODS: We report data from an international registry on CVST after COVID-19 vaccination. VITT was classified according to the Pavord criteria. We compared CVST-VITT cases from LMICs to cases from high-income countries (HICs). RESULTS: Until August 2022, 228 CVST cases were reported, of which 63 were from LMICs (all middle-income countries [MICs]: Brazil, China, India, Iran, Mexico, Pakistan, Turkey). Of these 63, 32 (51%) met the VITT criteria, compared to 103 of 165 (62%) from HICs. Only 5 of the 32 (16%) CVST-VITT cases from MICs had definite VITT, mostly because anti-platelet factor 4 antibodies were often not tested. The median age was 26 (interquartile range [IQR] 20-37) versus 47 (IQR 32-58) years, and the proportion of women was 25 of 32 (78%) versus 77 of 103 (75%) in MICs versus HICs, respectively. Patients from MICs were diagnosed later than patients from HICs (1/32 [3%] vs. 65/103 [63%] diagnosed before May 2021). Clinical manifestations, including intracranial hemorrhage, were largely similar as was intravenous immunoglobulin use. In-hospital mortality was lower in MICs (7/31 [23%, 95% confidence interval (CI) 11-40]) than in HICs (44/102 [43%, 95% CI 34-53], p = 0.039). CONCLUSIONS: The number of CVST-VITT cases reported from LMICs was small despite the widespread use of adenoviral vaccines. Clinical manifestations and treatment of CVST-VITT cases were largely similar in MICs and HICs, while mortality was lower in patients from MICs.

A scoring tool to predict mortality and dependency after cerebral venous thrombosis.

BACKGROUND AND PURPOSE: A prognostic score was developed to predict dependency and death after cerebral venous thrombosis (CVT) to identify patients for targeted therapy in future clinical trials. METHODS: Data from the International CVT Consortium were used. Patients with pre-existent functional dependency were excluded. Logistic regression was used to predict poor outcome (modified Rankin Scale score 3-6) at 6 months and Cox regression to predict 30-day and 1-year all-cause mortality. Potential predictors derived from previous studies were selected with backward stepwise selection. Coefficients were shrunk using ridge regression to adjust for optimism in internal validation. RESULTS: Of 1454 patients with CVT, the cumulative number of deaths was 44 (3%) and 70 (5%) for 30 days and 1 year, respectively. Of 1126 patients evaluated regarding functional outcome, 137 (12%) were dependent or dead at 6 months. From the retained predictors for both models, the SI2 NCAL2 C score was derived utilizing the following components: absence of female-sex-specific risk factor, intracerebral hemorrhage, infection of the central nervous system, neurological focal deficits, coma, age, lower level of hemoglobin (g/l), higher level of glucose (mmol/l) at admission, and cancer. C-statistics were 0.80 (95% confidence interval [CI] 0.75-0.84), 0.84 (95% CI 0.80-0.88) and 0.84 (95% CI 0.80-0.88) for the poor outcome, 30-day and 1-year mortality model, respectively. Calibration plots indicated a good model fit between predicted and observed values. The SI2 NCAL2 C score calculator is freely available at www.cerebralvenousthrombosis.com. CONCLUSIONS: The SI2 NCAL2 C score shows adequate performance for estimating individual risk of mortality and dependency after CVT but external validation of the score is warranted.

Long-term risk of recurrent vascular events and mortality in young stroke patients: Insights from a multicenter study.

BACKGROUND: Although the incidence of stroke in the young is rising, data on long-term outcomes in these patients are scarce. We thus aimed to investigate the long-term risk of recurrent vascular events and mortality in a multicenter study. METHODS: We followed 396 consecutive patients aged 18-55 years with ischemic stroke (IS) or transient ischemic attack (TIA) enrolled in three European centers during the period 2007-2010. A detailed outpatient clinical follow-up assessment was performed between 2018 and 2020. When an in-person follow-up visit was not possible, outcome events were assessed using electronic records and registry data. RESULTS: During a median follow-up of 11.8 (IQR 10.4-12.7) years, 89 (22.5%) patients experienced any recurrent vascular event, 62 (15.7%) had any cerebrovascular event, 34 (8.6%) had other vascular events, and 27 (6.8%) patients died. Cumulative 10-year incidence rate per 1000 person-years was 21.6 (95% CI 17.1-26.9) for any recurrent vascular event and 14.9 (95% CI 11.3-19.3) for any cerebrovascular event. The prevalence of cardiovascular risk factors increased over time, and 22 (13.5%) patients lacked any secondary preventive medication at the in-person follow-up. After adjustment for demographics and comorbidities, atrial fibrillation at baseline was found to be significantly associated with recurrent vascular events. CONCLUSIONS: This multicenter study shows a considerable risk of recurrent vascular events in young IS and TIA patients. Further studies should investigate whether detailed individual risk assessment, modern secondary preventive strategies, and better patient adherence may reduce recurrence risk.

Decompressive surgery in cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia.

BACKGROUND AND PURPOSE: Cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) is an adverse drug reaction occurring after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. CVST-VITT patients often present with large intracerebral haemorrhages and a high proportion undergoes decompressive surgery. Clinical characteristics, therapeutic management and outcomes of CVST-VITT patients who underwent decompressive surgery are described and predictors of in-hospital mortality in these patients are explored. METHODS: Data from an ongoing international registry of patients who developed CVST within 28 days of SARS-CoV-2 vaccination, reported between 29 March 2021 and 10 May 2022, were used. Definite, probable and possible VITT cases, as defined by Pavord et al. (N Engl J Med 2021; 385: 1680-1689), were included. RESULTS: Decompressive surgery was performed in 34/128 (27%) patients with CVST-VITT. In-hospital mortality was 22/34 (65%) in the surgical and 27/94 (29%) in the non-surgical group (p < 0.001). In all surgical cases, the cause of death was brain herniation. The highest mortality rates were found amongst patients with preoperative coma (17/18, 94% vs. 4/14, 29% in the non-comatose; p < 0.001) and bilaterally absent pupillary reflexes (7/7, 100% vs. 6/9, 67% with unilaterally reactive pupil, and 4/11, 36% with bilaterally reactive pupils; p = 0.023). Postoperative imaging revealed worsening of index haemorrhagic lesion in 19 (70%) patients and new haemorrhagic lesions in 16 (59%) patients. At a median follow-up of 6 months, 8/10 of surgical CVST-VITT who survived admission were functionally independent. CONCLUSIONS: Almost two-thirds of surgical CVST-VITT patients died during hospital admission. Preoperative coma and bilateral absence of pupillary responses were associated with higher mortality rates. Survivors often achieved functional independence.

Radiomics-Derived Brain Age Predicts Functional Outcome After Acute Ischemic Stroke.

BACKGROUND AND OBJECTIVES: While chronological age is one of the most influential determinants of poststroke outcomes, little is known of the impact of neuroimaging-derived biological "brain age." We hypothesized that radiomics analyses of T2-FLAIR images texture would provide brain age estimates and that advanced brain age of patients with stroke will be associated with cardiovascular risk factors and worse functional outcomes. METHODS: We extracted radiomics from T2-FLAIR images acquired during acute stroke clinical evaluation. Brain age was determined from brain parenchyma radiomics using an ElasticNet linear regression model. Subsequently, relative brain age (RBA), which expresses brain age in comparison with chronological age-matched peers, was estimated. Finally, we built a linear regression model of RBA using clinical cardiovascular characteristics as inputs and a logistic regression model of favorable functional outcomes taking RBA as input. RESULTS: We reviewed 4,163 patients from a large multisite ischemic stroke cohort (mean age = 62.8 years, 42.0% female patients). T2-FLAIR radiomics predicted chronological ages (mean absolute error = 6.9 years, r = 0.81). After adjustment for covariates, RBA was higher and therefore described older-appearing brains in patients with hypertension, diabetes mellitus, a history of smoking, and a history of a prior stroke. In multivariate analyses, age, RBA, NIHSS, and a history of prior stroke were all significantly associated with functional outcome (respective adjusted odds ratios: 0.58, 0.76, 0.48, 0.55; all p-values < 0.001). Moreover, the negative effect of RBA on outcome was especially pronounced in minor strokes. DISCUSSION: T2-FLAIR radiomics can be used to predict brain age and derive RBA. Older-appearing brains, characterized by a higher RBA, reflect cardiovascular risk factor accumulation and are linked to worse outcomes after stroke.

Delayed Development of Aneurysmal Dilatations in Patients with Extracranial Carotid Artery Dissections.

OBJECTIVE: Dissection of the carotid artery (CaAD) may result in aneurysm formation. The present study was undertaken to evaluate the time of onset of post-dissection extracranial carotid artery aneurysms (ECAA) following CaAD, and to analyse independent risk factors for the development of these aneurysms. METHODS: From four European stroke centres, 360 patients with extracranial CaAD were included. The time between the estimated dissection onset and aneurysm formation was analysed, and the clinical risk factors increasing the probability of aneurysm were assessed. RESULTS: The median duration of follow up was 5.2 months (range 0 - 24 months). A total of 75 post-dissection ECAAs were identified in 70 patients (19.4%, 95% confidence interval [CI] 15.7 - 23.8). In 52 of 70 (74%) patients, the ECAA was diagnosed at the initial clinical work up of CaAD diagnosis, with the median estimated time of dissection onset to ECAA diagnosis being six days (interquartile range [IQR] 0 - 25). In the remaining 18 (26%) patients who had normal carotid arteries at the initial imaging, the aneurysm diagnosis was made a median of 6.2 months (189 days) from the original imaging (IQR 128 - 198). A Cox proportional hazards model showed that both multiple artery dissections (hazard ratio [HR] 2.58, 95% CI 1.54 - 4.33) and arterial tortuosity (HR 1.79, 95% CI 1.08 - 2.95) were associated with presence of ipsilateral ECAA. CONCLUSION: This post hoc cohort analysis showed substantially delayed development of ipsilateral ECAA in patients with CaAD, months after baseline. Multiple dissections and arterial tortuosity are associated with the presence of ECAA and can be used in future prediction models of ECAA development in patients with CaAD.

Cancer and stroke: commonly encountered by clinicians, but little evidence to guide clinical approach.

The association between stroke and cancer is well-established. Because of an aging population and longer survival rates, the frequency of synchronous stroke and cancer will become even more common. Different pathophysiologic mechanisms have been proposed how cancer or cancer treatment directly or via coagulation disturbances can mediate stroke. Increased serum levels of D-dimer, fibrin degradation products, and CRP are more often seen in stroke with concomitant cancer, and the clot retrieved during thrombectomy has a more fibrin- and platelet-rich constitution compared with that of atherosclerotic etiology. Multiple infarctions are more common in patients with active cancer compared with those without a cancer diagnosis. New MRI techniques may help in detecting typical patterns seen in the presence of a concomitant cancer. In ischemic stroke patients, a newly published cancer probability score can help clinicians in their decision-making when to suspect an underlying malignancy in a stroke patient and to start cancer-screening studies. Treating stroke patients with synchronous cancer can be a delicate matter. Limited evidence suggests that administration of intravenous thrombolysis appears safe in non-axial intracranial and non-metastatic cancer patients. Endovascular thrombectomy is probably rather safe in these patients, but probably futile in most patients placed on palliative care due to their advanced disease. In this topical review, we discuss the epidemiology, pathophysiology, and prognosis of ischemic and hemorrhagic strokes as well as cerebral venous thrombosis and concomitant cancer. We further summarize the current evidence on acute management and secondary preventive therapy.

Markers of early vascular aging are not associated with cryptogenic ischemic stroke in the young: A case-control study.

BACKGROUND AND PURPOSE: We aimed to assess the association between covert atherosclerosis, arterial stiffness, and early-onset cryptogenic ischemic stroke (CIS) in a prospective case-control study. METHODS: We enrolled 123 young CIS patients (median age 41 years; 42% women) and 123 age- and sex-matched controls. Carotid intima-media thickness (CIMT), Augmentation Index (AIx), central pulse wave velocity (PWV), and subendocardial viability ratio (SEVR) were compared between patients and controls. Conditional logistic regression was used adjusting for age, systolic blood pressure, diastolic blood pressure, current smoking, total cholesterol/high-density lipoprotein cholesterol (Total-C/HDL-C) ratio, and glycated albumin to assess the independent association between CIMT, arterial stiffness and CIS. RESULTS: Patients with higher CIMT and PWV were older, more often men and they had more frequently well-documented risk factors, lower HDL and higher Total-C/HDL-C ratio compared to other tertiles. In univariate comparisons, we found no differences between patients and controls regarding CIMT, AIx, or PWV. In the entire cohort, patients had a significantly lower SEVR compared to controls (146.3%, interquartile range [IQR] 125.7-170.3 vs. 158.0%, IQR 141.3-181.0, P=0.010). SEVR was lower also in women compared to their controls (132.0%, IQR 119.4-156.1 vs. 158.7%, IQR 142.0-182.8, P=0.001) but no significant difference appeared between male patients and male controls. However, after adjusting for comorbidities and laboratory values these significant differences were lost (odds ratio [OR] 1.52, 95% confidence interval [CI] 0.47-4.91) in the entire cohort and OR 3.89, 95% CI 0.30-50.80 in women). CONCLUSIONS: Higher CIMT and PWV were associated to higher age, male sex, and several well-documented cardiovascular risk factors. However, in this study we could not prove that either covert atherosclerosis or arterial stiffness contribute to pathogenesis of early-onset CIS.

Does tranexamic acid affect intraventricular hemorrhage growth in acute ICH? An analysis of the STOP-AUST trial.

Background: Trials of tranexamic acid (TXA) in acute intracerebral hemorrhage (ICH) have focused on the imaging outcomes of intraparenchymal hematoma growth. However, intraventricular hemorrhage (IVH) growth is also strongly associated with outcome after ICH. Revised definitions of hematoma expansion incorporating IVH growth have been proposed. Aims: We sought to evaluate the effect of TXA on IVH growth. Methods: We analyzed data from the STOP-AUST trial, a prospective randomized trial comparing TXA to placebo in ICH patients presenting ≤ 4.5 h from symptom onset with a CT-angiography spot sign. New IVH development at follow-up, any interval IVH growth, and IVH growth ≥ 1 mL were compared between the treatment groups using logistic regression. The treatment effect of TXA against placebo using conventional (> 6 mL or 33%), and revised definitions of hematoma expansion (> 6 mL or 33% or IVH expansion ≥ 1 mL, > 6 mL or 33%, or any IVH expansion, and > 6 mL or 33% or new IVH development) were also assessed. Treatment effects were adjusted for baseline ICH volume. Results: The analysis population consisted of 99 patients (50 placebo, 49 TXA). New IVH development at follow-up was observed in 6/49 (12%) who received TXA and 13/50 (26%) who received placebo (aOR: 0.38 [95% CI: 0.13-1.13]). Any interval IVH growth was observed in 12/49 (25%) who received TXA versus 26/50 (32%) receiving placebo (aOR: 0.69 [95% CI: 0.28-1.66]). IVH growth ≥ 1 mL did not differ between the two groups. Using revised definitions of hematoma expansion, no significant difference in treatment effect was observed between TXA and placebo. Conclusions: IVH may be attenuated by TXA following ICH; however, studies with larger cohorts are required to investigate this further. Registration: http://www.clinicaltrials.gov; Unique identifier: NCT01702636.

Declining mortality of cerebral venous sinus thrombosis with thrombocytopenia after SARS-CoV-2 vaccination.

BACKGROUND AND PURPOSE: High mortality rates have been reported in patients with cerebral venous sinus thrombosis (CVST) due to vaccine-induced immune thrombotic thrombocytopenia (VITT) after vaccination with adenoviral vector SARS-CoV-2 vaccines. The aim of this study was to evaluate whether the mortality of patients with CVST-VITT has decreased over time. METHODS: The EudraVigilance database of the European Medicines Agency was used to identify cases of CVST with concomitant thrombocytopenia occurring within 28 days of SARS-CoV-2 vaccination. Vaccines were grouped based on vaccine type (adenoviral or mRNA). Cases with CVST onset until 28 March were compared to cases after 28 March 2021, which was the day when the first scientific paper on VITT was published. RESULTS: In total, 270 cases of CVST with thrombocytopenia were identified, of which 266 (99%) occurred after adenoviral vector SARS-CoV-2 vaccination (ChAdOx1 nCoV-19, n = 243; Ad26.COV2.S, n = 23). The reported mortality amongst adenoviral cases with onset up to 28 March 2021 was 47/99 (47%, 95% confidence interval 37%-58%) compared to 36/167 (22%, 95% confidence interval 16%-29%) in cases with onset after 28 March (p < 0.001). None of the four cases of CVST with thrombocytopenia occurring after mRNA vaccination died. CONCLUSION: The reported mortality of CVST with thrombocytopenia after vaccination with adenoviral vector-based SARS-CoV-2 vaccines has significantly decreased over time, which may indicate a beneficial effect of earlier recognition and/or improved treatment on outcome after VITT.

Excessive White Matter Hyperintensity Increases Susceptibility to Poor Functional Outcomes After Acute Ischemic Stroke.

Objective: To personalize the prognostication of post-stroke outcome using MRI-detected cerebrovascular pathology, we sought to investigate the association between the excessive white matter hyperintensity (WMH) burden unaccounted for by the traditional stroke risk profile of individual patients and their long-term functional outcomes after a stroke. Methods: We included 890 patients who survived after an acute ischemic stroke from the MRI-Genetics Interface Exploration (MRI-GENIE) study, for whom data on vascular risk factors (VRFs), including age, sex, atrial fibrillation, diabetes mellitus, hypertension, coronary artery disease, smoking, prior stroke history, as well as acute stroke severity, 3- to-6-month modified Rankin Scale score (mRS), WMH, and brain volumes, were available. We defined the unaccounted WMH (uWMH) burden via modeling of expected WMH burden based on the VRF profile of each individual patient. The association of uWMH and mRS score was analyzed by linear regression analysis. The odds ratios of patients who achieved full functional independence (mRS < 2) in between trichotomized uWMH burden groups were calculated by pair-wise comparisons. Results: The expected WMH volume was estimated with respect to known VRFs. The uWMH burden was associated with a long-term functional outcome (ß = 0.104, p < 0.01). Excessive uWMH burden significantly reduced the odds of achieving full functional independence after a stroke compared to the low and average uWMH burden [OR = 0.4, 95% CI: (0.25, 0.63), p < 0.01 and OR = 0.61, 95% CI: (0.42, 0.87), p < 0.01, respectively]. Conclusion: The excessive amount of uWMH burden unaccounted for by the traditional VRF profile was associated with worse post-stroke functional outcomes. Further studies are needed to evaluate a lifetime brain injury reflected in WMH unrelated to the VRF profile of a patient as an important factor for stroke recovery and a plausible indicator of brain health.

Endothelial Dysfunction is Associated With Early-Onset Cryptogenic Ischemic Stroke in Men and With Increasing Age.

Background The aim of this study was to assess the association between endothelial function and early-onset cryptogenic ischemic stroke (CIS), with subgroup analyses stratified by sex and age groups. Methods and Results We prospectively enrolled 136 consecutive patients aged 18 to 49 years (median age, 41 years; 44% women) with a recent CIS and 136 age- and sex-matched (±5 years) stroke-free controls. Endothelial function was measured with an EndoPAT 2000 device and analyzed as tertiles of natural logarithm of reactive hyperemia index with lower values reflecting dysfunction. We used conditional logistic regression adjusting for age, education, hypertension, diabetes mellitus, dyslipidemia, current smoking, heavy drinking, obesity, and diet score to assess the independent association between endothelial function and CIS. Patients in the lowest tertile of natural logarithm of reactive hyperemia index were more often men and they more frequently had a history of dyslipidemia; they were also more often obese, had a lower diet score, and lower high-density lipoprotein cholesterol. In the entire cohort, we found no association in patients with endothelial function and CIS compared with stroke-free controls. In sex- and age-specific analyses, endothelial dysfunction was associated with CIS in men (adjusted odds ratio [OR], 3.50 for lowest versus highest natural logarithm of reactive hyperemia index tertile; 95% CI, 1.22-10.07) and in patients ≥41 years (OR, 5.78; 95% CI, 1.52-21.95). These associations remained significant when dyslipidemia was replaced with the ratio of total to high-density lipoprotein cholesterol. Conclusions Endothelial dysfunction appears to be an independent player in early-onset CIS in men and patients approaching middle age.

MRI Radiomic Signature of White Matter Hyperintensities Is Associated With Clinical Phenotypes.

OBJECTIVE: Neuroimaging measurements of brain structural integrity are thought to be surrogates for brain health, but precise assessments require dedicated advanced image acquisitions. By means of quantitatively describing conventional images, radiomic analyses hold potential for evaluating brain health. We sought to: (1) evaluate radiomics to assess brain structural integrity by predicting white matter hyperintensities burdens (WMH) and (2) uncover associations between predictive radiomic features and clinical phenotypes. METHODS: We analyzed a multi-site cohort of 4,163 acute ischemic strokes (AIS) patients with T2-FLAIR MR images with total brain and WMH segmentations. Radiomic features were extracted from normal-appearing brain tissue (brain mask-WMH mask). Radiomics-based prediction of personalized WMH burden was done using ElasticNet linear regression. We built a radiomic signature of WMH with stable selected features predictive of WMH burden and then related this signature to clinical variables using canonical correlation analysis (CCA). RESULTS: Radiomic features were predictive of WMH burden (R 2 = 0.855 ± 0.011). Seven pairs of canonical variates (CV) significantly correlated the radiomics signature of WMH and clinical traits with respective canonical correlations of 0.81, 0.65, 0.42, 0.24, 0.20, 0.15, and 0.15 (FDR-corrected p-values CV 1 - 6 < 0.001, p-value CV 7 = 0.012). The clinical CV1 was mainly influenced by age, CV2 by sex, CV3 by history of smoking and diabetes, CV4 by hypertension, CV5 by atrial fibrillation (AF) and diabetes, CV6 by coronary artery disease (CAD), and CV7 by CAD and diabetes. CONCLUSION: Radiomics extracted from T2-FLAIR images of AIS patients capture microstructural damage of the cerebral parenchyma and correlate with clinical phenotypes, suggesting different radiographical textural abnormalities per cardiovascular risk profile. Further research could evaluate radiomics to predict the progression of WMH and for the follow-up of stroke patients' brain health.

Per-pass analysis of acute ischemic stroke clots: impact of stroke etiology on extracted clot area and histological composition.

BACKGROUND: Initial studies investigating correlations between stroke etiology and clot composition are conflicting and do not account for clot size as determined by area. Radiological studies have shown that cardioembolic strokes are associated with shorter clot lengths and lower clot burden than non-cardioembolic clots. OBJECTIVE: To report the relationship between stroke etiology, extracted clot area, and histological composition at each procedural pass. METHODS: As part of the multi-institutional RESTORE Registry, the Martius Scarlett Blue stained histological composition and extracted clot area of 612 per-pass clots retrieved from 441 patients during mechanical thrombectomy procedures were quantified. Correlations with clinical and procedural details were investigated. RESULTS: Clot composition varied significantly with procedural passes; clots retrieved in earlier passes had higher red blood cell content (H4=11.644, p=0.020) and larger extracted clot area (H4=10.730, p=0.030). Later passes were associated with significantly higher fibrin (H4=12.935, p=0.012) and platelets/other (H4=15.977, p=0.003) content and smaller extracted clot area. Large artery atherosclerotic (LAA) clots were significantly larger in the extracted clot area and more red blood cell-rich than other etiologies in passes 1-3. Cardioembolic and cryptogenic clots had similar histological composition and extracted clot area across all procedural passes. CONCLUSION: LAA clots are larger and associated with a large red blood cell-rich extracted clot area, suggesting soft thrombus material. Cardioembolic clots are smaller in the extracted clot area, consistent in composition and area across passes, and have higher fibrin and platelets/other content than LAA clots, making them stiffer clots. The per-pass histological composition and extracted clot area of cryptogenic clots are similar to those of cardioembolic clots, suggesting similar formation mechanisms.

MRI Characterization of Non-traumatic Intracerebral Hemorrhage in Young Adults.

Background and Purpose: Non-traumatic intracerebral hemorrhage (ICH) in younger population is a relatively rare event but is associated with considerable mortality and poor functional outcome. Imaging plays a crucial role in determining the underlying cause and guide treatment of ICH. In up to 41% of patients in prior studies, the underlying cause remained elusive. However, the usage of MRI as part of diagnostic work-up was scanty. We aimed to analyze MRI findings of ICH in younger patients and assess specificity and sensitivity of MRI in detecting structural or local underlying causes of ICH. Methods: We included patients aged 15-49 years with first-ever ICH identified from a prospective hospital discharge registry, 2000-2010. All study patients underwent MRI within 3 months of ICH. Imaging data was analyzed by a senior neuroradiologist blinded to final clinical diagnosis. We calculated the diagnostic accuracy of MRI in detecting structural/local underlying causes. Results: Of our 116 patients (median age, 39; 67% males), structural/local causes were the leading causes of ICH (50.0%), and of these, bleeding cavernomas (23.3%) were the most frequent followed by arteriovenous malformations (12.9%), cerebral venous thrombosis (CVT) (7.8%), brain tumors (5.2%), and moyamoya disease (0.9%). Lobar location of ICH was more prevalent in younger patients. MRI was highly sensitive (90.0%; 95% confidence interval, 79.5-96.2%) for detection of structural/local causes compared with angiographic imaging (55.6%; 95% CI, 40.0-70.4%), while MRI was less specific (87.3%; 95% CI, 75.5-94.7%) for structural/local causes, compared with angiographic imaging (97.4%; 95% CI, 86.5-99.9%). Conclusion: MRI was highly sensitive for the detection of structural and local causes underlying ICH in young adults. Thus, MRI should be considered in the diagnostic work-up of all young ICH patients to enable targeted secondary prevention.

Brain Volume: An Important Determinant of Functional Outcome After Acute Ischemic Stroke.

OBJECTIVE: To determine whether brain volume is associated with functional outcome after acute ischemic stroke (AIS). PATIENTS AND METHODS: This study was conducted between July 1, 2014, and March 16, 2019. We analyzed cross-sectional data of the multisite, international hospital-based MRI-Genetics Interface Exploration study with clinical brain magnetic resonance imaging obtained on admission for index stroke and functional outcome assessment. Poststroke outcome was determined using the modified Rankin Scale score (0-6; 0 = asymptomatic; 6 = death) recorded between 60 and 190 days after stroke. Demographic characteristics and other clinical variables including acute stroke severity (measured as National Institutes of Health Stroke Scale score), vascular risk factors, and etiologic stroke subtypes (Causative Classification of Stroke system) were recorded during index admission. RESULTS: Utilizing the data from 912 patients with AIS (mean ± SD age, 65.3±14.5 years; male, 532 [58.3%]; history of smoking, 519 [56.9%]; hypertension, 595 [65.2%]) in a generalized linear model, brain volume (per 155.1 cm3) was associated with age (ß -0.3 [per 14.4 years]), male sex (ß 1.0), and prior stroke (ß -0.2). In the multivariable outcome model, brain volume was an independent predictor of modified Rankin Scale score (ß -0.233), with reduced odds of worse long-term functional outcomes (odds ratio, 0.8; 95% CI, 0.7-0.9) in those with larger brain volumes. CONCLUSION: Larger brain volume quantified on clinical magnetic resonance imaging of patients with AIS at the time of stroke purports a protective mechanism. The role of brain volume as a prognostic, protective biomarker has the potential to forge new areas of research and advance current knowledge of the mechanisms of poststroke recovery.