Baseline characteristics and outcome of stroke patients after endovascular therapy according to previous symptomatic vascular disease and sex.

Aim: The aim of this study was to investigate baseline characteristics and outcome of patients after endovascular therapy (EVT) for acute large vessel occlusion (LVO) in relation to their history of symptomatic vascular disease and sex. Methods: Consecutive EVT-eligible patients with LVO in the anterior circulation admitted to our stroke center between 04/2015 and 04/2020 were included in this observational cohort study. All patients were treated according to a standardized acute ischaemic stroke (AIS) protocol. Baseline characteristics and successful reperfusion, recurrent/progressive in-hospital ischaemic stroke, symptomatic in-hospital intracranial hemorrhage, death at discharge and at 3 months, and functional outcome at 3 months were analyzed according to previous symptomatic vascular disease and sex. Results: 995 patients with LVO in the anterior circulation (49.4% women, median age 76 years, median admission NIHSS score 14) were included. Patients with multiple vs. no previous vascular events showed higher mortality at discharge (20% vs. 9.3%, age/sex - adjustedOR = 1.43, p = 0.030) and less independency at 3 months (28.8% vs. 48.8%, age/sex - adjustedOR = 0.72, p = 0.020). All patients and men alone with one or multiple vs. patients and men with no previous vascular events showed more recurrent/progressive in-hospital ischaemic strokes (19.9% vs. 6.4% in all patients, age/sex - adjustedOR = 1.76, p = 0.028) (16.7% vs. 5.8% in men, age-adjustedOR = 2.20, p = 0.035). Men vs. women showed more in-hospital symptomatic intracranial hemorrhage among patients with one or multiple vs. no previous vascular events (23.7% vs. 6.6% in men and 15.4% vs. 5.5% in women, OR = 2.32, p = 0.035/age - adjustedOR = 2.36, p = 0.035). Conclusions: Previous vascular events increased the risk of in-hospital complications and poorer outcome in the analyzed patients with EVT-eligible LVO-AIS. Our findings may support risk assessment in these stroke patients and could contribute to the design of future studies.

Early Versus Late Initiation of Direct Oral Anticoagulants After Ischemic Stroke in People With Atrial Fibrillation and Hemorrhagic Transformation: Prespecified Subanalysis of the Randomized-controlled ELAN Trial.

BACKGROUND: Whether hemorrhagic transformation (HT) modifies the treatment effect of early versus late initiation of direct oral anticoagulation (DOAC) in people with ischemic stroke and atrial fibrillation is unknown. METHODS: This is a post-hoc analysis of the ELAN trial. The primary outcome was a composite of recurrent ischemic stroke, symptomatic intracranial hemorrhage (sICH), major extracranial bleeding, systemic embolism, or vascular death within 30 days. Secondary outcomes were the individual components, 30- and 90-day functional outcome. We estimated outcomes based on HT, subclassified as hemorrhagic infarction (HI) or parenchymal hemorrhage (PH) on pre-randomization imaging (core-lab rating) using adjusted risk differences (aRD) between treatment arms. RESULTS: Overall, 247/1970 (12.5%) participants had HT (114 HI 1, 77 HI 2, 34 PH 1, 22 PH 2). For the primary outcome, the estimated aRD (early versus late) was -2.2% (-7.8 to 3.5%) in people with HT (HI: -4.7%, -10.8 to 1.4%; PH: 6.1%, -8.4 to 20.7%), and -0.9% (-2.6 to 0.8%) in people without. Numbers of sICH were identical in people with and without HT. With early treatment, the estimated aRD for poor 90-day functional outcome (mRS 3-6) was 11.4% (-0.9 to 23.7%) in participants with HT (HI: 7.2%, -6.6 to 21.0%; PH: 25.1%, 0.2 to 50.0%), and -2.6% (-7.1 to 1.8%) in people without HT. CONCLUSIONS: We found no evidence of major treatment effect heterogeneity or safety concerns with early versus late DOAC initiation in people with and without HT. However, early DOAC initiation may worsen functional outcomes in people with PH.

Intravenous thrombolysis in patients with recent intake of direct oral anticoagulants: A target trial analysis after the liberalization of institutional guidelines.

INTRODUCTION: This study aimed to report the safety and efficacy of off-label intravenous thrombolysis (IVT) with alteplase after sequentially liberalizing our institutional guidelines allowing IVT for patients under direct oral anticoagulants (DOACs) regardless of plasma levels, time of last intake, and without prior anticoagulation reversal therapy. PATIENTS AND METHODS: We utilized the target-trial methodology to emulate hypothetical criteria of a randomized controlled trial in our prospective stroke registry. Consecutive DOAC patients (06/2021-11/2023) otherwise qualifying for IVT were included. Safety and efficacy outcomes (symptomatic intracranial hemorrhage [ICH], any radiological ICH, major bleeding, 90-day mortality, 90-day good functional outcome [mRS 0-2 or return to baseline]) were assessed using inverse-probability-weighted regression-adjustment comparing patients with versus without IVT. RESULTS: Ninety eight patients fulfilled the target-trial criteria. IVT was given in 49/98 (50%) patients at a median of 178 (interquartile range 134-285) min after symptom onset with median DOAC plasma level of 77 ng/ml (15 patients had plasma levels > 100 ng/ml; 25/49 [51%] were treated within 12 h after last DOAC ingestion). Endovascular therapy was more frequent in patients without IVT (73% vs 33%). Symptomatic ICH occurred in 0/49 patients receiving IVT and 2/49 patients without IVT (adjusted difference -2.5%; 95% CI -5.9 to 0.8). The rates of any radiological ICH were comparable. Patients receiving IVT were more likely to have good functional outcomes. DISCUSSION AND CONCLUSION: After liberalizing our approach for IVT regardless of recent DOAC intake, we did not experience any safety concerns. The association of IVT with better functional outcomes warrants prospective randomized controlled trials.

Early vs Late Anticoagulation in Minor, Moderate, and Major Ischemic Stroke With Atrial Fibrillation: Post Hoc Analysis of the ELAN Randomized Clinical Trial.

Importance: Whether infarct size modifies the treatment effect of early vs late direct oral anticoagulant (DOAC) initiation in people with ischemic stroke and atrial fibrillation is unknown. Objective: To assess whether infarct size modifies the safety and efficacy of early vs late DOAC initiation. Design, Setting, and Participants: Post hoc analysis of participants from the multinational (>100 sites in 15 countries) randomized clinical Early Versus Later Anticoagulation for Stroke With Atrial Fibrillation (ELAN) trial who had (1) acute ischemic stroke, (2) atrial fibrillation, and (3) brain imaging available before randomization. The ELAN trial was conducted between October 2017 and December 2022. Data were analyzed from October to December 2023 for this post hoc analysis. Intervention: Early vs late DOAC initiation after ischemic stroke. Early DOAC initiation was within 48 hours for minor or moderate stroke or on days 6 to 7 for major stroke; late DOAC initiation was on days 3 to 4 for minor stroke, days 6 to 7 for moderate stroke, and days 12 to 14 for major stroke. Main Outcomes and Measures: The primary outcome was a composite of recurrent ischemic stroke, symptomatic intracranial hemorrhage, extracranial bleeding, systemic embolism, or vascular death within 30 days. The outcome was assessed according to infarct size (minor, moderate, or major) using odds ratios and risk differences between treatment arms. Interrater reliability for infarct size between the core laboratory and local raters was assessed, and whether this modified the estimated treatment effects was also examined. Results: A total of 1962 of the original 2013 participants (909 [46.3%] female; median [IQR] age, 77 [70-84] years) were included. The primary outcome occurred in 10 of 371 participants (2.7%) with early DOAC initiation vs 11 of 364 (3.0%) with late DOAC initiation among those with minor stroke (odds ratio [OR], 0.89; 95% CI, 0.38-2.10); in 11 of 388 (2.8%) with early DOAC initiation vs 14 of 392 (3.6%) with late DOAC initiation among those with moderate stroke (OR, 0.80; 95% CI, 0.35-1.74); and in 8 of 219 (3.7%) with early DOAC initiation vs 16 of 228 (7.0%) with late DOAC initiation among those with major stroke (OR, 0.52; 95% CI, 0.21-1.18). The 95% CI for the estimated risk difference of the primary outcome in early anticoagulation was -2.78% to 2.12% for minor stroke, -3.23% to 1.76% for moderate stroke, and -7.49% to 0.81% for major stroke. There was no significant treatment interaction for the primary outcome. For infarct size, interrater reliability was moderate (κ = 0.675; 95% CI, 0.647-0.702) for local vs core laboratory raters and strong (κ = 0.875; 95% CI, 0.855-0.894) between core laboratory raters. Conclusions and Relevance: The treatment effect of early DOAC initiation did not differ in people with minor, moderate, or major stroke assessed by brain imaging. Early treatment was not associated with a higher rate of adverse events, especially symptomatic intracranial hemorrhage, for any infarct size, including major stroke. Trial Registration: ClinicalTrials.gov Identifier: NCT03148457.

The analysis of association between single features of small vessel disease and stroke outcome shows the independent impact of the number of microbleeds and presence of lacunes.

The impact of small vessel disease (SVD) on stroke outcome was investigated either separately for its single features in isolation or for SVD sum score measuring a qualitative (binary) assessment of SVD-lesions. We aimed to investigate which SVD feature independently impacts the most on stroke outcome and to compare the continuous versus binary SVD assessment that reflects pronouncement and presence correspondingly. Patients with a first-ever anterior circulation ischemic stroke were retrospectively investigated. We performed an ordered logistic regression analysis to predict stroke outcome (mRS 3 months, 0-6) using age, stroke severity, and pre-stroke disability as baseline input variables and adding SVD-features (lacunes, microbleeds, enlarged perivascular spaces, white matter hyperintensities) assessed either continuously (model 1) or binary (model 2). The data of 873 patients (age 67.9 ± 15.4, NIHSS 24 h 4.1 ± 4.8) was analyzed. In model 1 with continuous SVD-features, the number of microbleeds was the only independent predictor of stroke outcome in addition to clinical parameters (OR 1.21; 95% CI 1.07-1.37). In model 2 with the binary SVD assessment, only the presence of lacunes independently improved the prediction of stroke outcome (OR 1.48, 1.1-1.99). In a post hoc analysis, both the continuous number of microbleeds and the presence of lacunes were independent significant predictors. Thus, the number of microbleeds evaluated continuously and the presence of lacunes are associated with stroke outcome independent from age, stroke severity, pre-stroke disability and other SVD-features. Whereas the presence of lacunes is adequately represented in SVD sum score, the microbleeds assessment might require another cutoff and/or gradual scoring, when prediction of stroke outcome is needed.

Intracerebral haemorrhage in patients taking different types of oral anticoagulants: a pooled individual patient data analysis from two national stroke registries.

BACKGROUND: We investigated outcomes in patients with intracerebral haemorrhage (ICH) according to prior anticoagulation treatment with Vitamin K antagonists (VKAs), direct oral anticoagulants (DOACs) or no anticoagulation. METHODS: This is an individual patient data study combining two prospective national stroke registries from Switzerland and Norway (2013-2019). We included all consecutive patients with ICH from both registries. The main outcomes were favourable functional outcome (modified Rankin Scale 0-2) and mortality at 3 months. RESULTS: Among 11 349 patients with ICH (mean age 73.6 years; 47.6% women), 1491 (13.1%) were taking VKAs and 1205 (10.6%) DOACs (95.2% factor Xa inhibitors). The median percentage of patients on prior anticoagulation was 23.7 (IQR 22.6-25.1) with VKAs decreasing (from 18.3% to 7.6%) and DOACs increasing (from 3.0% to 18.0%) over time. Prior VKA therapy (n=209 (22.3%); adjusted ORs (aOR), 0.64; 95% CI, 0.49 to 0.84) and prior DOAC therapy (n=184 (25.7%); aOR, 0.64; 95% CI, 0.47 to 0.87) were independently associated with lower odds of favourable outcome compared with patients without anticoagulation (n=2037 (38.8%)). Prior VKA therapy (n=720 (49.4%); aOR, 1.71; 95% CI, 1.41 to 2.08) and prior DOAC therapy (n=460 (39.7%); aOR, 1.28; 95% CI, 1.02 to 1.60) were independently associated with higher odds of mortality compared with patients without anticoagulation (n=2512 (30.2%)). CONCLUSIONS: The spectrum of anticoagulation-associated ICH changed over time. Compared with patients without prior anticoagulation, prior VKA treatment and prior DOAC treatment were independently associated with lower odds of favourable outcome and higher odds of mortality at 3 months. Specific reversal agents unavailable during the study period might improve outcomes of DOAC-associated ICH in the future.

Time for "code ICH"? - Workflow metrics of hyperacute treatments and outcome in patients with intracerebral haemorrhage.

INTRODUCTION: Knowledge about uptake and workflow metrics of hyperacute treatments in patients with non-traumatic intracerebral haemorrhage (ICH) in the emergency department are scarce. METHODS: Single centre retrospective study of consecutive patients with ICH between 01/2018-08/2020. We assessed uptake and workflow metrics of acute therapies overall and according to referral mode (stroke code, transfer from other hospital or other). RESULTS: We enrolled 332 patients (age 73years, IQR 63-81 and GCS 14 points, IQR 11-15, onset-to-admission-time 284 minutes, IQR 111-708minutes) of whom 101 patients (35%) had lobar haematoma. Mode of referral was stroke code in 129 patients (38%), transfer from other hospital in 143 patients (43%) and arrival by other means in 60 patients (18%). Overall, 143 of 216 (66%) patients with systolic blood pressure >150mmHG received IV antihypertensive and 67 of 76 (88%) on therapeutic oral anticoagulation received prothrombin complex concentrate treatment (PCC). Forty-six patients (14%) received any neurosurgical intervention within 3 hours of admission. Median treatment times from admission to first IV-antihypertensive treatment was 38 minutes (IQR 18-72minutes) and 59 minutes (IQR 37-111 minutes) for PCC, with significant differences according to mode of referral (p<0.001) but not early arrival (≤6hours of onset, p=0.92). The median time in the emergency department was 139 minutes (IQR 85-220 minutes) and among patients with elevated blood pressure, only 44% achieved a successful control (<140mmHG) during ED stay. In multivariate analysis, code ICH concordant treatment was associated with significantly lower odds for in-hopsital mortality (aOR 0.30, 95%CI 0.12-0.73, p=0.008) and a non-significant trends towards better functional outcome measured using the modified Rankin scale score at 3 months (aOR for ordinal shift 0.54 95%CI 0.26-1.12, p=0.097). CONCLUSION: Uptake of hyperacute therapies for ICH treatment in the ED is heterogeneous. Treatment delays are short but not all patients achieve treatment targets during ED stay. Code ICH concordant treatment may improve clinical outcomes. Further improvements seem achievable advocating for a "code ICH" to streamline acute treatments.

CADMUS: A Novel MRI-Based Classification of Spontaneous Intracerebral Hemorrhage Associated With Cerebral Small Vessel Disease

BACKGROUND AND OBJECTIVES: Cerebral small vessel disease (SVD) is the major cause of intracerebral hemorrhage (ICH). There is no comprehensive, easily applicable classification of ICH subtypes according to the presumed underlying SVD using MRI. We developed an MRI-based classification for SVD-related ICH. METHODS: We performed a retrospective study in the prospectively collected Swiss Stroke Registry (SSR, 2013-2019) and the Stroke InvestiGation in North And central London (SIGNAL) cohort. Patients with nontraumatic, SVD-related ICH and available MRI within 3 months were classified as Cerebral Amyloid angiopathy (CAA), Deep perforator arteriopathy (DPA), Mixed CAA-DPA, or Undetermined SVD using hemorrhagic and nonhemorrhagic MRI markers (CADMUS classification). The primary outcome was inter-rater reliability using Gwet's AC1. Secondary outcomes were recurrent ICH/ischemic stroke at 3 months according to the CADMUS phenotype. We performed Firth penalized logistic regressions and competing risk analyses. RESULTS: The SSR cohort included 1,180 patients (median age [interquartile range] 73 [62-80] years, baseline NIH Stroke Scale 6 [2-12], 45.6% lobar hematoma, systolic blood pressure on admission 166 [145-185] mm Hg). The CADMUS phenotypes were as follows: mixed CAA-DPA (n = 751 patients, 63.6%), undetermined SVD (n = 203, 17.2%), CAA (n = 154, 13.1%), and DPA (n = 72, 6.3%), with a similar distribution in the SIGNAL cohort (n = 313). Inter-rater reliability was good (Gwet's AC1 for SSR/SIGNAL 0.69/0.74). During follow-up, 56 patients had 57 events (28 ICH, 29 ischemic strokes). Three-month event rates were comparable between the CADMUS phenotypes. DISCUSSION: CADMUS, a novel MRI-based classification for SVD-associated ICH, is feasible and reproducible and may improve the classification of ICH subtypes in clinical practice and research.

Clinical Associations and Prognostic Value of MRI-Visible Perivascular Spaces in Patients With Ischemic Stroke or TIA: A Pooled Analysis

BACKGROUND AND OBJECTIVES: Visible perivascular spaces are an MRI marker of cerebral small vessel disease and might predict future stroke. However, results from existing studies vary. We aimed to clarify this through a large collaborative multicenter analysis. METHODS: We pooled individual patient data from a consortium of prospective cohort studies. Participants had recent ischemic stroke or transient ischemic attack (TIA), underwent baseline MRI, and were followed up for ischemic stroke and symptomatic intracranial hemorrhage (ICH). Perivascular spaces in the basal ganglia (BGPVS) and perivascular spaces in the centrum semiovale (CSOPVS) were rated locally using a validated visual scale. We investigated clinical and radiologic associations cross-sectionally using multinomial logistic regression and prospective associations with ischemic stroke and ICH using Cox regression. RESULTS: We included 7,778 participants (mean age 70.6 years; 42.7% female) from 16 studies, followed up for a median of 1.44 years. Eighty ICH and 424 ischemic strokes occurred. BGPVS were associated with increasing age, hypertension, previous ischemic stroke, previous ICH, lacunes, cerebral microbleeds, and white matter hyperintensities. CSOPVS showed consistently weaker associations. Prospectively, after adjusting for potential confounders including cerebral microbleeds, increasing BGPVS burden was independently associated with future ischemic stroke (versus 0-10 BGPVS, 11-20 BGPVS: HR 1.19, 95% CI 0.93-1.53; 21+ BGPVS: HR 1.50, 95% CI 1.10-2.06; p = 0.040). Higher BGPVS burden was associated with increased ICH risk in univariable analysis, but not in adjusted analyses. CSOPVS were not significantly associated with either outcome. DISCUSSION: In patients with ischemic stroke or TIA, increasing BGPVS burden is associated with more severe cerebral small vessel disease and higher ischemic stroke risk. Neither BGPVS nor CSOPVS were independently associated with future ICH.

Andexanet alfa versus non-specific treatments for intracerebral hemorrhage in patients taking factor Xa inhibitors - Individual patient data analysis of ANNEXA-4 and TICH-NOAC.

BACKGROUND: Data comparing the specific reversal agent andexanet alfa with non-specific treatments in patients with non-traumatic intracerebral hemorrhage (ICH) associated with factor-Xa inhibitor (FXaI) use are scarce. AIM: The study aimed to determine the association between the use of andexanet alfa compared with non-specific treatments with the rate of hematoma expansion and thromboembolic complications in patients with FXaI-associated ICH. METHODS: We performed an individual patient data analysis combining two independent, prospective studies: ANNEXA-4 (180 patients receiving andexanet alfa, NCT02329327) and TICH-NOAC (63 patients receiving tranexamic acid or placebo ± prothrombin complex concentrate, NCT02866838). The primary efficacy outcome was hematoma expansion on follow-up imaging. The primary safety outcome was any thromboembolic complication (ischemic stroke, myocardial infarction, pulmonary embolism, or deep vein thrombosis) at 30 days. We used binary logistic regression models adjusted for baseline hematoma volume, age, calibrated anti-Xa activity, times from last intake of FXaI, and symptom onset to treatment, respectively. RESULTS: Among 243 participants included, the median age was 80 (IQR 75-84) years, baseline hematoma volume was 9.1 (IQR 3.4-21) mL and anti-Xa activity 118 (IQR 78-222) ng/mL. Times from last FXaI intake and symptom onset to treatment were 11 (IQR 7-16) and 4.7 (IQR 3.0-7.6) h, respectively. Overall, 50 patients (22%) experienced hematoma expansion (ANNEXA-4: n=24 (14%); TICH-NOAC: n=26 (41%)). After adjusting for pre-specified confounders (baseline hematoma volume, age, calibrated anti-Xa activity, times from last intake of FXaI, and symptom onset to treatment, respectively), treatment with andexanet alfa was independently associated with decreased odds for hematoma expansion (aOR 0.33, 95% CI 0.13-0.80, p = 0.015). Overall, 26 patients (11%) had any thromboembolic complication within 30 days (ANNEXA-4: n=20 (11%); TICH-NOAC: n=6 (10%)). There was no association between any thromboembolic complication and treatment with andexanet alfa (aOR 0.70, 95% CI 0.16-3.12, p = 0.641). CONCLUSION: The use of andexanet alfa compared to any other non-specific treatment strategy was associated with decreased odds for hematoma expansion, without increased odds for thromboembolic complications.

Geographical Requirements for the Applicability of the Results of the RACECAT Study to Other Stroke Networks.

Background The RACECAT (Transfer to the Closest Local Stroke Center vs Direct Transfer to Endovascular Stroke Center of Acute Stroke Patients With Suspected Large Vessel Occlusion in the Catalan Territory) trial was the first randomized trial addressing the prehospital triage of acute stroke patients based on the distribution of thrombolysis centers and intervention centers in Catalonia, Spain. The study compared the drip-and-ship with the mothership paradigm in regions where a local thrombolysis center can be reached faster than the nearest intervention center (equipoise region). The present study aims to determine the population-based applicability of the results of the RACECAT study to 4 stroke networks with a different degree of clustering of the intervention centers (clustered, dispersed). Methods and Results Stroke networks were compared with regard to transport time saved for thrombolysis (under the drip-and-ship approach) and transport time saved for endovascular therapy (under the mothership approach). Population-based transport times were modeled with a local instance of an openrouteservice server using open data from OpenStreetMap.The fraction of the population in the equipoise region differed substantially between clustered networks (Catalonia, 63.4%; France North, 87.7%) and dispersed networks (Southwest Bavaria, 40.1%; Switzerland, 40.0%). Transport time savings for thrombolysis under the drip-and-ship approach were more marked in clustered networks (Catalonia, 29 minutes; France North, 27 minutes) than in dispersed networks (Southwest Bavaria and Switzerland, both 18 minutes). Conclusions Infrastructure differences between stroke networks may hamper the applicability of the results of the RACECAT study to other stroke networks with a different distribution of intervention centers. Stroke networks should assess the population densities and hospital type/distribution in the temporal domain before applying prehospital triage algorithms to their specific setting.

Small vessel disease burden and risk of recurrent cerebrovascular events in patients with lacunar stroke and intracerebral haemorrhage attributable to deep perforator arteriolopathy.

INTRODUCTION: Deep perforator arteriolopathy (DPA) causes intracerebral haemorrhage (ICH) and lacunar strokes (LS). We compare patient characteristics, MRI findings and clinical outcomes among patients with deep ICH and LS. PATIENTS AND METHODS: We included patients with MRI-confirmed LS or ICH in the basal ganglia, thalamus, internal capsule or brainstem from the Bernese Stroke Registry. We assessed MRI small vessel disease (SVD) markers, SVD burden score, modified Rankin Scale (mRS) and ischaemic stroke or ICH at 3 months. RESULTS: We included 716 patients, 117 patients (16.3%) with deep ICH (mean age (SD) 65.1 (±15.2) years, 37.1% female) and 599 patients (83.7%) with LS (mean age (SD) 69.7 (±13.6) years, 39.9% female). Compared to LS, deep ICH was associated with a higher SVD burden score (median (IQR) 2 (1-2) vs 1 (0-2)), aORshift 3.19, 95%CI 2.15-4.75). Deep ICH patients had more often cerebral microbleeds (deep ICH: 71.6% vs LS: 29.2%, p < 0.001, median count (IQR) 4(2-12) vs 2(1-6)) and a higher prevalence of lacunes (deep ICH: 60.5% vs LS: 27.4% p < 0.001). At 3 months, deep ICH was associated with higher mRS (aORshift 2.16, 95%CI 1.21-3.87). Occurrence of ischaemic stroke was numerically but not significantly higher in deep ICH (4.3% vs 2.9%; p = 0.51). One patient (1.1%) with ICH but none with LS suffered ICH recurrence. DISCUSSION/CONCLUSION: DPA manifesting as ICH is associated with more severe MRI SVD burden and worse outcome compared to LS. The short-term risks of subsequent ischaemic stroke and recurrent ICH are similar in ICH and LS patients. This implies potential consequences for future secondary prevention strategies.

Connecting Women in Neurosciences: A networking project to sustain mutual empowerment in young, female clinical neuroscientists.

Simultaneously acquiring broad clinical knowledge and scientific expertise is a major challenge for young clinical scientists. Female researchers may face additional hurdles in their career, for example, due to unconscious bias. We aimed to address clinical, research, and gender-related challenges among young female clinical neuroscientists. We implemented a peer-led networking group dedicated to increasing clinical and scientific knowledge, improve soft skills, and encourage exchange between fellow residents. In monthly meetings, two participants hold short presentations on a clinical topic or scientific method, followed by a discussion and feedback to the presenter. Afterwards, participants network and discuss challenges they face in their daily experience. Nine neurology residents at a Swiss University Hospital with ≤3 years of training participated in the Connecting Women in Neurosciences project from August 2020 to June 2021. In a qualitative evaluation, participants reported they felt empowered by these meetings and profited from their new network. We identified several challenges in combining clinical and research activities, some of which participants perceived to be gender-related. In addition to women-only meetings, we will promote events addressing all interested researchers. Peer-to-peer networking is an easy and low-budget intervention to encourage female residents to engage in research activities, profit from each other's expertise, and promote interdisciplinary teamwork. It can provide a protected environment to discuss and overcome in particular gender-related challenges. We encourage young colleagues to regularly engage in structured networking activities with their local peers.

Impact of Cerebral Microbleeds in Stroke Patients with Atrial Fibrillation.

OBJECTIVES: Cerebral microbleeds are associated with the risks of ischemic stroke and intracranial hemorrhage, causing clinical dilemmas for antithrombotic treatment decisions. We aimed to evaluate the risks of intracranial hemorrhage and ischemic stroke associated with microbleeds in patients with atrial fibrillation treated with vitamin K antagonists, direct oral anticoagulants, antiplatelets, and combination therapy (i.e. concurrent oral anticoagulant and antiplatelet). METHODS: We included patients with documented atrial fibrillation from the pooled individual patient data analysis by the Microbleeds International Collaborative Network. Risks of subsequent intracranial hemorrhage and ischemic stroke were compared between patients with and without microbleeds, stratified by antithrombotic use. RESULTS: A total of 7,839 patients were included. The presence of microbleeds was associated with an increased relative risk of intracranial hemorrhage (adjusted hazard ratio [aHR] = 2.74, 95% confidence interval = 1.76-4.26) and ischemic stroke (aHR = 1.29, 95% confidence interval = 1.04-1.59). For the entire cohort, the absolute incidence of ischemic stroke was higher than intracranial hemorrhage regardless of microbleed burden. However, for the subgroup of patients taking combination of anticoagulant and antiplatelet therapy, the absolute risk of intracranial hemorrhage exceeded that of ischemic stroke in those with 2 to 4 microbleeds (25 vs 12 per 1,000 patient-years) and ≥ 11 microbleeds (94 vs 48 per 1,000 patient-years). INTERPRETATION: Patients with atrial fibrillation and high burden of microbleeds receiving combination therapy have a tendency of higher rate of intracranial hemorrhage than ischemic stroke, with potential for net harm. Further studies are needed to help optimize stroke preventive strategies in this high-risk group. ANN NEUROL 2023;94:61-74.

Stroke Risk and Antithrombotic Treatment During Follow-up of Patients With Ischemic Stroke and Cortical Superficial Siderosis.

BACKGROUND AND OBJECTIVES: In patients with ischemic stroke (IS) or transient ischemic attack (TIA) and cortical superficial siderosis (cSS), there are few data regarding the risk of future cerebrovascular events and also about the benefits and safety of antithrombotic drugs for secondary prevention. We investigated the associations of cSS and stroke risk in patients with recent IS or TIA. METHODS: We retrospectively analyzed the Microbleeds International Collaborative Network (MICON) database. We selected patients with IS or TIA from cohorts who had MRI-assessed cSS, available data on antithrombotic treatments, recurrent cerebrovascular events (intracranial hemorrhage [ICrH], IS, or any stroke [ICrH or IS]), and mortality. We calculated incidence rates (IRs) and performed univariable and multivariable Cox regression analyses. RESULTS: Of 12,669 patients (mean age 70.4 ± 12.3 years, 57.3% men), cSS was detected in 273 (2.2%) patients. During a mean follow-up of 24 ± 17 months, IS was more frequent than ICrH in both cSS (IR 57.1 vs 14.6 per 1,000 patient-years) and non-cSS (33.7 vs 6.3 per 1,000 patient-years) groups. Compared with the non-cSS group, cSS was associated with any stroke on multivariable analysis {IR 83 vs 42 per 1,000 patient-years, adjusted hazard ratio [HR] for cSS 1.62 (95% CI: 1.14-2.28; p = 0.006)}. This association was not significant in subgroups of patients treated with antiplatelet drugs (n = 6,554) or with anticoagulants (n = 4,044). Patients with cSS who were treated with both antiplatelet drugs and anticoagulants (n = 1,569) had a higher incidence of ICrH (IR 107.5 vs 4.9 per 1,000 patient-years, adjusted HR 13.26; 95% CI: 2.90-60.63; p = 0.001) and of any stroke (IR 198.8 vs 34.7 per 1,000 patient-years, adjusted HR 5.03; 95% CI: 2.03-12.44; p < 0.001) compared with the non-cSS group. DISCUSSION: Patients with IS or TIA with cSS are at increased risk of stroke (ICrH or IS) during follow-up; the risk of IS exceeds that of ICrH for patients receiving antiplatelet or anticoagulant treatment alone, but the risk of ICrH exceeds that of IS in patients receiving both treatments. The findings suggest that either antiplatelet or anticoagulant treatment alone should not be avoided in patients with cSS, but combined antithrombotic therapy might be hazardous. Our findings need to be confirmed by randomized clinical trials.

Submillimeter T1 atlas for subject-specific abnormality detection at 7T.

PURPOSE: Studies at 3T have shown that T1 relaxometry enables characterization of brain tissues at the single-subject level by comparing individual physical properties to a normative atlas. In this work, an atlas of normative T1 values at 7T is introduced with 0.6 mm isotropic resolution and its clinical potential is explored in comparison to 3T. METHODS: T1 maps were acquired in two separate healthy cohorts scanned at 3T and 7T. Using transfer learning, a template-based brain segmentation algorithm was adapted to ultra-high field imaging data. After segmenting brain tissues, volumes were normalized into a common space, and an atlas of normative T1 values was established by modeling the T1 inter-subject variability. A method for single-subject comparisons restricted to white matter and subcortical structures was developed by computing Z-scores. The comparison was applied to eight patients scanned at both field strengths for proof of concept. RESULTS: The proposed method for morphometry delivered segmentation masks without statistically significant differences from those derived with the original pipeline at 3T and achieved accurate segmentation at 7T. The established normative atlas allowed characterizing tissue alterations in single-subject comparisons at 7T, and showed greater anatomical details compared with 3T results. CONCLUSION: A high-resolution quantitative atlas with an adapted pipeline was introduced and validated. Several case studies on different clinical conditions showed the feasibility, potential and limitations of high-resolution single-subject comparisons based on quantitative MRI atlases. This method in conjunction with 7T higher resolution broadens the range of potential applications of quantitative MRI in clinical practice.

A Causal Classification System for Intracerebral Hemorrhage Subtypes.

OBJECTIVE: Determining the underlying causes of intracerebral hemorrhage (ICH) is of major importance, because risk factors, prognosis, and management differ by ICH subtype. We developed a new causal CLASsification system for ICH Subtypes, termed CLAS-ICH, based on recent advances in neuroimaging. METHODS: CLAS-ICH defines 5 ICH subtypes: arteriolosclerosis, cerebral amyloid angiopathy, mixed small vessel disease (SVD), other rare forms of SVD (genetic SVD and others), and secondary causes (macrovascular causes, tumor, and other rare causes). Every patient is scored in each category according to the level of diagnostic evidence: (1) well-defined ICH subtype; (2) possible underlying disease; and (0) no evidence of the disease. We evaluated CLAS-ICH in a derivation cohort of 113 patients with ICH from Massachusetts General Hospital, Boston, USA, and in a derivation cohort of 203 patients from Inselspital, Bern, Switzerland. RESULTS: In the derivation cohort, a well-defined ICH subtype could be identified in 74 (65.5%) patients, including 24 (21.2%) with arteriolosclerosis, 23 (20.4%) with cerebral amyloid angiopathy, 18 (15.9%) with mixed SVD, and 9 (8.0%) with a secondary cause. One or more possible causes were identified in 42 (37.2%) patients. Interobserver agreement was excellent for each category (kappa value ranging from 0.86 to 1.00). Despite substantial differences in imaging modalities, we obtained similar results in the validation cohort. INTERPRETATION: CLAS-ICH is a simple and reliable classification system for ICH subtyping, that captures overlap between causes and the level of diagnostic evidence. CLAS-ICH may guide clinicians to identify ICH causes, and improve ICH classification in multicenter studies. ANN NEUROL 2023;93:16-28.

Association of Chronic Covert Cerebral Infarctions and White Matter Hyperintensities With Atrial Fibrillation Detection on Post-Stroke Cardiac Rhythm Monitoring: A Cohort Study.

Background This study was conducted to explore the association of different phenotypes, count, and location of chronic covert brain infarctions (CBIs) with detection of atrial fibrillation (AF) on prolonged post-stroke cardiac rhythm monitoring (PCM). Methods and Results We conducted a cohort single-center study of consecutive first-ever ischemic stroke or transient ischemic attack patients undergoing PCM between January 2015 and December 2017. We blindly rated CBI phenotypes according to established definitions and white matter hyperintensities (WMHs) according to the age-related white matter changes rating scale. We used (multiple) regression models to assess the association of the imaging biomarkers and incident AF on PCM. A total of 795 patients (median [interquartile range]) aged 69 (57-78) years, 41% women, median National Institutes of Health Stroke Scale score 2 (0-5), median PCM duration 14 (7-14) days, and AF detection in 61 patients (7.7%) were included. On univariate analysis, WMHs (per point odds ratio, 1.35 [95% CI, 1.03-1.78]) but not CBIs (odds ratio, 0.90 [95% CI, 0.52-1.56]) were associated with AF detection. Neither CBI phenotype, count, nor location were associated with AF detection. After adjustment for age, hypertension, and stroke severity, neither increasing WMHs (per point adjusted odds ratio, 0.85 [95% CI, 0.60-1.20]) nor CBIs (adjusted odds ratio, 0.60 [95% CI, 0.33-1.09]) were independently associated with AF detection. Conclusions Although WMHs and CBIs represent surrogate biomarkers of vascular risk factors, neither WMHs nor CBIs, including their phenotypes, count, and location, were independently associated with AF detection on PCM. In patients with manifest ischemic stroke or transient ischemic attack, the presence of imaging biomarkers of chronic ischemic injury does not seem promising to further refine prediction tools for AF detection on PCM.

Chronic cerebral infarctions and white matter lesions link to long-term survival after a first ischemic event: A cohort study.

BACKGROUND AND PURPOSE: To investigate the association of different phenotypes, count, and locations of chronic covert brain infarctions (CBI) with long-term mortality in patients with first-ever manifest acute ischemic stroke (AIS) or transient ischemic attack (TIA). Additionally, to analyze their potential interaction with white matter hyperintensities (WMH) and predictive value in addition to established mortality scores. METHODS: Single-center cohort study including consecutive patients with first-ever AIS or TIA with available MRI imaging from January 2015 to December 2017. Blinded raters adjudicated CBI phenotypes and WMH (age-related white matter changes score) according to established definitions. We compared Cox regression models including prespecified established predictors of mortality using Harrell's C and likelihood ratio tests. RESULTS: A total of 2236 patients (median [interquartile range] age: 71 [59-80] years, 43% female, National Institutes of Health Stroke Scale: 2 [1-6], median follow-up: 1436 days, 21% death during follow-up) were included. Increasing WMH (per point adjusted Hazard Ratio [aHR] = 1.29 [1.14-1.45]), but not CBI (aHR = 1.21 [0.99-1.49]), were independently associated with mortality. Neither CBI phenotype, count, nor location was associated with mortality and there was no multiplicative interaction between CBI and WMH (p > .1). As compared to patients without CBI or WMH, patients with moderate or severe WMH and additional CBI had the highest hazards of death (aHR = 1.62 [1.23-2.13]). The Cox regression model including CBI and WMH had a small but significant increment in Harrell's C when compared to the model including 14 clinical variables (0.831 vs. 0.827, p < .001). DISCUSSION: WMH represent a strong surrogate biomarker of long-term mortality in first-ever manifest AIS or TIA patients. CBI phenotypes, count, and location seem less relevant. Incorporation of CBI and WMH slightly improves predictive capacity of established risk scores.

Multivariable Prediction Model for Futile Recanalization Therapies in Patients With Acute Ischemic Stroke.

BACKGROUND AND OBJECTIVES: Very poor outcome despite intravenous thrombolysis (IVT) and mechanical thrombectomy (MT) occurs in about 1 of 4 patients with ischemic stroke and is associated with a high logistic and economic burden. We aimed to develop and validate a multivariable prognostic model to identify futile recanalization therapies (FRT) in patients undergoing those therapies. MATERIALS AND METHODS: Patients from a prospectively collected observational registry of a single academic stroke center treated with MT and/or IVT were included. The dataset was split into a training (N=1808, 80%) and internal validation (N=453, 20%) cohort. We used gradient boosted decision tree machine-learning models after k-NN imputation of 32 variables available at admission to predict FRT defined as modified Rankin-Scale (mRS) 5-6 at 3 months. We report feature importance, ability for discrimination, calibration and decision curve analysis. RESULTS: 2261 patients with a median (IQR) age 75 years (64-83), 46% female, median NIHSS 9 (4-17), 34% IVT alone, 41% MT alone, 25% bridging were included. Overall 539 (24%) had FRT, more often in MT alone (34%) as compared to IVT alone (11%). Feature importance identified clinical variables (stroke severity, age, active cancer, prestroke disability), laboratory values (glucose, CRP, creatinine), imaging biomarkers (white matter hyperintensities) and onset-to-admission time as the most important predictors. The final model was discriminatory for predicting 3-month FRT (AUC 0.87, 95% CI 0.87-0.88) and had good calibration (Brier 0.12, 0.11-0.12). Overall performance was moderate (F1-score 0.63 ± 0.004) and decision curve analyses suggested higher mean net benefit at lower thresholds of treatment (up to 0.8). CONCLUSIONS: This FRT prediction model can help inform shared decision making and identify the most relevant features in the emergency setting. While it might be particularly useful in low resource healthcare settings, incorporation of further multifaceted variables is necessary to further increase the predictive performance.