A multitrait genetic study of hemostatic factors and hemorrhagic transformation after stroke treatment.

BACKGROUND: Thrombolytic recombinant tissue plasminogen activator (r-tPA) treatment is the only pharmacologic intervention available in the ischemic stroke acute phase. This treatment is associated with an increased risk of intracerebral hemorrhages, known as hemorrhagic transformations (HTs), which worsen the patient's prognosis. OBJECTIVES: To investigate the association between genetically determined natural hemostatic factors' levels and increased risk of HT after r-tPA treatment. METHODS: Using data from genome-wide association studies on the risk of HT after r-tPA treatment and data on 7 hemostatic factors (factor [F]VII, FVIII, von Willebrand factor [VWF], FXI, fibrinogen, plasminogen activator inhibitor-1, and tissue plasminogen activator), we performed local and global genetic correlation estimation multitrait analyses and colocalization and 2-sample Mendelian randomization analyses between hemostatic factors and HT. RESULTS: Local correlations identified a genomic region on chromosome 16 with shared covariance: fibrinogen-HT, P = 2.45 × 10-11. Multitrait analysis between fibrinogen-HT revealed 3 loci that simultaneously regulate circulating levels of fibrinogen and risk of HT: rs56026866 (PLXND1), P = 8.80 × 10-10; rs1421067 (CHD9), P = 1.81 × 10-14; and rs34780449, near ROBO1 gene, P = 1.64 × 10-8. Multitrait analysis between VWF-HT showed a novel common association regulating VWF and risk of HT after r-tPA at rs10942300 (ZNF366), P = 1.81 × 10-14. Mendelian randomization analysis did not find significant causal associations, although a nominal association was observed for FXI-HT (inverse-variance weighted estimate [SE], 0.07 [-0.29 to 0.00]; odds ratio, 0.87; 95% CI, 0.75-1.00; raw P = .05). CONCLUSION: We identified 4 shared loci between hemostatic factors and HT after r-tPA treatment, suggesting common regulatory mechanisms between fibrinogen and VWF levels and HT. Further research to determine a possible mediating effect of fibrinogen on HT risk is needed.

Long-term effectiveness and tolerability of galcanezumab in patients with migraine excluded from clinical trials: real world evidence of 1055 patients with 1 year follow-up from the Galca-Only registry.

BACKGROUND: Galcanezumab has shown efficacy and effectiveness in the treatment of episodic and chronic migraine (CM), however, the population represented in randomized clinical trials (RCTs) differs from the population observed in real-world setting. To describe the long-term effectiveness and tolerability of galcanezumab in clinical practice in patients excluded from RCTs. METHODS: Multicenter prospective cohort study of consecutive patients with chronic and high-frequency episodic migraine (HFEM) with prior failure to three or more migraine preventive drugs, treated with galcanezumab and followed up for 12 months. RESULTS: We enrolled 1055 patients, aged 50 (IQR: 42-58), 82.9% female, 76.4% chronic migraine, 69% with at least one exclusion criteria for RCTs, including age > 65 (n = 121), concomitant use of onabotulinumtoxinA (n = 185), daily headache at baseline (n = 347), chronic painful syndromes (n = 206), fibromyalgia (n = 101) or treatment resistance (n = 957). The median number of prior preventive treatments was 4 (IQR: 3-5). The retention rate was 90.8%, 76.8% and 71.4% at 3, 6 and 12 months. The main reasons for treatment discontinuation were lack of effectiveness (21.1%) and inadequate tolerability (6.6%). The 30%, 50% and 75% responder rates were 62.6%, 49.8% and 24.2% between weeks 8-12; 60.9%, 48.8% and 24.6% between weeks 20-24; and 59.7%, 48.3% and 24.6% between weeks 44-48. Daily headache at baseline (OR: 0.619; 95%CI: 0.469-0.817) and patient's age (OR: 1.016; 95%CI: 1.005-1.026) were associated with 50% response at weeks 20-24. The variables that were associated with a higher reduction of headache days between weeks 20-24 were patient's age (0.068; 95% CI: 0.018-0.119) and headache days per month at baseline (0.451; 95% CI: 0.319-0.583), while psychiatric comorbidity (-1.587; 95% CI: -2.626-0.538) and daily headache at baseline (-2.718; 95% CI: -4.58-0.869) were associated with fewer reduction in the number of headache days between weeks 20-24. CONCLUSION: This study provides class III evidence of effectiveness and tolerability of galcanezumab in patients with HFEM and CM with comorbidities that would result in exclusion of the pivotal RCTs. Nonetheless, the clinical results over a 12-month period were similar to the efficacy observed in randomized controlled trials. Few patients discontinued the drug due to inadequate tolerability.

A Polygenic Risk Score Based on a Cardioembolic Stroke Multitrait Analysis Improves a Clinical Prediction Model for This Stroke Subtype.

Background: Occult atrial fibrillation (AF) is one of the major causes of embolic stroke of undetermined source (ESUS). Knowing the underlying etiology of an ESUS will reduce stroke recurrence and/or unnecessary use of anticoagulants. Understanding cardioembolic strokes (CES), whose main cause is AF, will provide tools to select patients who would benefit from anticoagulants among those with ESUS or AF. We aimed to discover novel loci associated with CES and create a polygenetic risk score (PRS) for a more efficient CES risk stratification. Methods: Multitrait analysis of GWAS (MTAG) was performed with MEGASTROKE-CES cohort (n = 362,661) and AF cohort (n = 1,030,836). We considered significant variants and replicated those variants with MTAG p-value < 5 × 10-8 influencing both traits (GWAS-pairwise) with a p-value < 0.05 in the original GWAS and in an independent cohort (n = 9,105). The PRS was created with PRSice-2 and evaluated in the independent cohort. Results: We found and replicated eleven loci associated with CES. Eight were novel loci. Seven of them had been previously associated with AF, namely, CAV1, ESR2, GORAB, IGF1R, NEURL1, WIPF1, and ZEB2. KIAA1755 locus had never been associated with CES/AF, leading its index variant to a missense change (R1045W). The PRS generated has been significantly associated with CES improving discrimination and patient reclassification of a model with age, sex, and hypertension. Conclusion: The loci found significantly associated with CES in the MTAG, together with the creation of a PRS that improves the predictive clinical models of CES, might help guide future clinical trials of anticoagulant therapy in patients with ESUS or AF.

Multi-ancestry GWAS reveals excitotoxicity associated with outcome after ischaemic stroke.

During the first hours after stroke onset, neurological deficits can be highly unstable: some patients rapidly improve, while others deteriorate. This early neurological instability has a major impact on long-term outcome. Here, we aimed to determine the genetic architecture of early neurological instability measured by the difference between the National Institutes of Health Stroke Scale (NIHSS) within 6 h of stroke onset and NIHSS at 24 h. A total of 5876 individuals from seven countries (Spain, Finland, Poland, USA, Costa Rica, Mexico and Korea) were studied using a multi-ancestry meta-analyses. We found that 8.7% of NIHSS at 24 h of variance was explained by common genetic variations, and also that early neurological instability has a different genetic architecture from that of stroke risk. Eight loci (1p21.1, 1q42.2, 2p25.1, 2q31.2, 2q33.3, 5q33.2, 7p21.2 and 13q31.1) were genome-wide significant and explained 1.8% of the variability suggesting that additional variants influence early change in neurological deficits. We used functional genomics and bioinformatic annotation to identify the genes driving the association from each locus. Expression quantitative trait loci mapping and summary data-based Mendelian randomization indicate that ADAM23 (log Bayes factor = 5.41) was driving the association for 2q33.3. Gene-based analyses suggested that GRIA1 (log Bayes factor = 5.19), which is predominantly expressed in the brain, is the gene driving the association for the 5q33.2 locus. These analyses also nominated GNPAT (log Bayes factor = 7.64) ABCB5 (log Bayes factor = 5.97) for the 1p21.1 and 7p21.1 loci. Human brain single-nuclei RNA-sequencing indicates that the gene expression of ADAM23 and GRIA1 is enriched in neurons. ADAM23, a presynaptic protein and GRIA1, a protein subunit of the AMPA receptor, are part of a synaptic protein complex that modulates neuronal excitability. These data provide the first genetic evidence in humans that excitotoxicity may contribute to early neurological instability after acute ischaemic stroke.

Clinical and therapeutic variables may influence the association between infarct core predicted by CT perfusion and clinical outcome in acute stroke.

OBJECTIVES: After an acute ischemic stroke, patients with a large CT perfusion (CTP) predicted infarct core (pIC) have poor clinical outcome. However, previous research suggests that this relationship may be relevant for subgroups of patients determined by pretreatment and treatment-related variables while negligible for others. We aimed to identify these variables. METHODS: We included a cohort of 828 patients with acute proximal carotid arterial occlusions imaged with a whole-brain CTP within 8 h from stroke onset. pIC was computed on CTP Maps (cerebral blood flow < 30%), and poor clinical outcome was defined as a 90-day modified Rankin Scale score > 2. Potential mediators of the association between pIC and clinical outcome were evaluated through first-order and advanced interaction analyses in the derivation cohort (n = 654) for obtaining a prediction model. The derived model was further validated in an independent cohort (n = 174). RESULTS: The volume of pIC was significantly associated with poor clinical outcome (OR = 2.19, 95% CI = 1.73 - 2.78, p < 0.001). The strength of this association depended on baseline National Institute of Health Stroke Scale, glucose levels, the use of thrombectomy, and the interaction of age with thrombectomy. The model combining these variables showed good discrimination for predicting clinical outcome in both the derivation cohort and validation cohorts (area under the receiver operating characteristic curve 0.780 (95% CI = 0.746-0.815) and 0.782 (95% CI = 0.715-0.850), respectively). CONCLUSIONS: In patients imaged within 8 h from stroke onset, the association between pIC and clinical outcome is significantly modified by baseline and therapeutic variables. These variables deserve consideration when evaluating the prognostic relevance of pIC. KEY POINTS: •The volume of CT perfusion (CTP) predicted infarct core (pIC) is associated with poor clinical outcome in acute ischemic stroke imaged within 8 h of onset. •The relationship between pIC and clinical outcome may be modified by baseline clinical severity, glucose levels, thrombectomy use, and the interaction of age with thrombectomy. •CTP pIC should be evaluated in an individual basis for predicting clinical outcome in patients imaged within 8 h from stroke onset.

Characterization of Subarachnoid Hyperdensities After Thrombectomy for Acute Stroke Using Dual-Energy CT.

BACKGROUND AND OBJECTIVES: The presence of postinterventional subarachnoid hyperdensities (SA-HD) is a relatively common finding after mechanical thrombectomy (MT). We aimed to assess the incidence, characteristics, clinical relevance, and predictors of SA-HD after MT as categorized through the use of postinterventional dual-energy CT (DE-CT). METHODS: A single-center consecutive series of patients with acute stroke treated with MT was retrospectively reviewed. Posttreatment SA-HD were defined as incident extraaxial hyperdensities in a follow-up DE-CT performed within a median of 8 hours after MT. SA-HD were further classified according to their content (isolated contrast extravasation vs blood extravasation) and extension (diffuse [hyperdensities in more than one extraparenchymal compartment] vs nondiffuse). Adjusted logistic regression models assessed the association of SA-HD with pretreatment and procedural variables and with poor clinical outcome (shift towards worse categories in the ordinal Rankin Scale at 90 days). RESULTS: SA-HD were observed in 120 (28%) of the 424 included patients (isolated contrast extravasation n = 22, blood extravasation n = 98). In this group, SA-HD were diffuse in 72 (60%) patients (isolated contrast extravasation n = 7, blood extravasation n = 65) and nondiffuse in 48 (40%) patients (isolated contrast extravasation n = 15, blood extravasation n = 33). Diffuse SA-HD were significantly associated with worse clinical outcome in adjusted models (common odds ratio [cOR] 2.3, 95% confidence interval [CI] 1.36-4.00, p = 0.002), unlike the specific SA-HD content alone. In contrast with the absence of SA-HD, only the diffuse pattern with blood extravasation was significantly associated with worse clinical outcome (cOR 2.4, 95% CI 1.36-4.15, p = 0.002). Diffuse SA-HD patterns were predicted by M2 occlusions, more thrombectomy passes, and concurrent parenchymal hematomas. DISCUSSION: In our cohort of patients imaged within a median of 8 hours after MT, postinterventional SA-HD showed a diffuse pattern in 17% of thrombectomies and were associated with more arduous procedures. Diffuse SA-HD but not local collections of blood or contrast extravasations were associated with an increased risk of poor outcome and death. These findings reinforce the need for improvement in reperfusion strategies. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that in individuals with proximal carotid artery territory occlusions treated with MT, diffuse postinterventional SA-HD on imaging 8 hours postprocedure are associated with worse clinical outcomes at 90 days.

Effectiveness of Thrombectomy in Stroke According to Baseline Prognostic Factors: Inverse Probability of Treatment Weighting Analysis of a Population-Based Registry.

BACKGROUND AND PURPOSE:  In real-world practice, the benefit of mechanical thrombectomy (MT) is uncertain in stroke patients with very favorable or poor prognostic profiles at baseline. We studied the effectiveness of MT versus medical treatment stratifying by different baseline prognostic factors. METHODS:  Retrospective analysis of 2,588 patients with an ischemic stroke due to large vessel occlusion nested in the population-based registry of stroke code activations in Catalonia from January 2017 to June 2019. The effect of MT on good functional outcome (modified Rankin Score ≤2) and survival at 3 months was studied using inverse probability of treatment weighting (IPTW) analysis in three pre-defined baseline prognostic groups: poor (if pre-stroke disability, age >85 years, National Institutes of Health Stroke Scale [NIHSS] >25, time from onset >6 hours, Alberta Stroke Program Early CT Score <6, proximal vertebrobasilar occlusion, supratherapeutic international normalized ratio >3), good (if NIHSS <6 or distal occlusion, in the absence of poor prognostic factors), or reference (not meeting other groups' criteria). RESULTS:  Patients receiving MT (n=1,996, 77%) were younger, had less pre-stroke disability, and received systemic thrombolysis less frequently. These differences were balanced after the IPTW stratified by prognosis. MT was associated with good functional outcome in the reference (odds ratio [OR], 2.9; 95% confidence interval [CI], 2.0 to 4.4), and especially in the poor baseline prognostic stratum (OR, 3.9; 95% CI, 2.6 to 5.9), but not in the good prognostic stratum. MT was associated with survival only in the poor prognostic stratum (OR, 2.6; 95% CI, 2.0 to 3.3). CONCLUSIONS:  Despite their worse overall outcomes, the impact of thrombectomy over medical management was more substantial in patients with poorer baseline prognostic factors than patients with good prognostic factors.

RP11-362K2.2:RP11-767I20.1 Genetic Variation Is Associated with Post-Reperfusion Therapy Parenchymal Hematoma. A GWAS Meta-Analysis.

Stroke is one of the most common causes of death and disability. Reperfusion therapies are the only treatment available during the acute phase of stroke. Due to recent clinical trials, these therapies may increase their frequency of use by extending the time-window administration, which may lead to an increase in complications such as hemorrhagic transformation, with parenchymal hematoma (PH) being the more severe subtype, associated with higher mortality and disability rates. Our aim was to find genetic risk factors associated with PH, as that could provide molecular targets/pathways for their prevention/treatment and study its genetic correlations to find traits sharing genetic background. We performed a GWAS and meta-analysis, following standard quality controls and association analysis (fastGWAS), adjusting age, NIHSS, and principal components. FUMA was used to annotate, prioritize, visualize, and interpret the meta-analysis results. The total number of patients in the meta-analysis was 2034 (216 cases and 1818 controls). We found rs79770152 having a genome-wide significant association (beta 0.09, p-value 3.90 × 10-8) located in the RP11-362K2.2:RP11-767I20.1 gene and a suggestive variant (rs13297983: beta 0.07, p-value 6.10 × 10-8) located in PCSK5 associated with PH occurrence. The genetic correlation showed a shared genetic background of PH with Alzheimer's disease and white matter hyperintensities. In addition, genes containing the ten most significant associations have been related to aggregated amyloid-ß, tau protein, white matter microstructure, inflammation, and matrix metalloproteinases.

Single nucleotide variations in ZBTB46 are associated with post-thrombolytic parenchymal haematoma.

Haemorrhagic transformation is a complication of recombinant tissue-plasminogen activator treatment. The most severe form, parenchymal haematoma, can result in neurological deterioration, disability, and death. Our objective was to identify single nucleotide variations associated with a risk of parenchymal haematoma following thrombolytic therapy in patients with acute ischaemic stroke. A fixed-effect genome-wide meta-analysis was performed combining two-stage genome-wide association studies (n = 1904). The discovery stage (three cohorts) comprised 1324 ischaemic stroke individuals, 5.4% of whom had a parenchymal haematoma. Genetic variants yielding a P-value < 0.05 1 × 10-5 were analysed in the validation stage (six cohorts), formed by 580 ischaemic stroke patients with 12.1% haemorrhagic events. All participants received recombinant tissue-plasminogen activator; cases were parenchymal haematoma type 1 or 2 as defined by the European Cooperative Acute Stroke Study (ECASS) criteria. Genome-wide significant findings (P < 5 × 10-8) were characterized by in silico functional annotation, gene expression, and DNA regulatory elements. We analysed 7 989 272 single nucleotide polymorphisms and identified a genome-wide association locus on chromosome 20 in the discovery cohort; functional annotation indicated that the ZBTB46 gene was driving the association for chromosome 20. The top single nucleotide polymorphism was rs76484331 in the ZBTB46 gene [P = 2.49 × 10-8; odds ratio (OR): 11.21; 95% confidence interval (CI): 4.82-26.55]. In the replication cohort (n = 580), the rs76484331 polymorphism was associated with parenchymal haematoma (P = 0.01), and the overall association after meta-analysis increased (P = 1.61 × 10-8; OR: 5.84; 95% CI: 3.16-10.76). ZBTB46 codes the zinc finger and BTB domain-containing protein 46 that acts as a transcription factor. In silico studies indicated that ZBTB46 is expressed in brain tissue by neurons and endothelial cells. Moreover, rs76484331 interacts with the promoter sites located at 20q13. In conclusion, we identified single nucleotide variants in the ZBTB46 gene associated with a higher risk of parenchymal haematoma following recombinant tissue-plasminogen activator treatment.

Early Neurological Change After Ischemic Stroke Is Associated With 90-Day Outcome.

BACKGROUND AND PURPOSE: Large-scale observational studies of acute ischemic stroke (AIS) promise to reveal mechanisms underlying cerebral ischemia. However, meaningful quantitative phenotypes attainable in large patient populations are needed. We characterize a dynamic metric of AIS instability, defined by change in National Institutes of Health Stroke Scale score (NIHSS) from baseline to 24 hours baseline to 24 hours (NIHSSbaseline - NIHSS24hours = ΔNIHSS6-24h), to examine its relevance to AIS mechanisms and long-term outcomes. METHODS: Patients with NIHSS prospectively recorded within 6 hours after onset and then 24 hours later were enrolled in the GENISIS study (Genetics of Early Neurological Instability After Ischemic Stroke). Stepwise linear regression determined variables that independently influenced ΔNIHSS6-24h. In a subcohort of tPA (alteplase)-treated patients with large vessel occlusion, the influence of early sustained recanalization and hemorrhagic transformation on ΔNIHSS6-24h was examined. Finally, the association of ΔNIHSS6-24h with 90-day favorable outcomes (modified Rankin Scale score 0-2) was assessed. Independent analysis was performed using data from the 2 NINDS-tPA stroke trials (National Institute of Neurological Disorders and Stroke rt-PA). RESULTS: For 2555 patients with AIS, median baseline NIHSS was 9 (interquartile range, 4-16), and median ΔNIHSS6-24h was 2 (interquartile range, 0-5). In a multivariable model, baseline NIHSS, tPA-treatment, age, glucose, site, and systolic blood pressure independently predicted ΔNIHSS6-24h (R2=0.15). In the large vessel occlusion subcohort, early sustained recanalization and hemorrhagic transformation increased the explained variance (R2=0.27), but much of the variance remained unexplained. ΔNIHSS6-24h had a significant and independent association with 90-day favorable outcome. For the subjects in the 2 NINDS-tPA trials, ΔNIHSS3-24h was similarly associated with 90-day outcomes. CONCLUSIONS: The dynamic phenotype, ΔNIHSS6-24h, captures both explained and unexplained mechanisms involved in AIS and is significantly and independently associated with long-term outcomes. Thus, ΔNIHSS6-24h promises to be an easily obtainable and meaningful quantitative phenotype for large-scale genomic studies of AIS.

Clinical improvement within 24 hours from mechanical thrombectomy as a predictor of long-term functional outcome in a multicenter population-based cohort of patients with ischemic stroke.

BACKGROUND: Single-center studies have suggested that the early clinical course after mechanical thrombectomy (MT) in patients with ischemic stroke is a clinical predictor of long-term outcome. OBJECTIVE: To analyze the prognostic value of clinical improvement within 24 hours in a population-based multicenter cohort. METHODS: From a total of 3792 patients with acute ischemic stroke in Catalonia (CICAT registry), 1951 patients were treated with MT. The National Institutes of Health Stroke Scale (NIHSS) score within 24 hours, and follow-up was available in 1666 patients. Percentage variation in the NIHSS score was calculated in relation to a baseline assessment. Good outcome was defined as a modified Rankin Scale score ≤2 at 90 days. Predictive values of clinical improvement and adjusted OR to predict good outcomes were assessed in the whole cohort and the subgroup of patients with posterior circulation stroke (n=166). RESULTS: Good outcome was achieved in 656/1666 patients (39%) overall. Percentage improvements both at the end of MT and at 24 hours predicted good outcome, with higher predictive capacity at 24 hours (C-statistic, 0.85 vs 0.73, p<0.001). Positive and negative predictive values were 70% and 74% for the >30% cut-off point at the end of MT, and 69% and 84% for the >50% cut-off point at 24 hours, respectively. The adjusted OR for good outcome was 5.8 (95% CI 4.2 to 8.1) and 12.9 (95% CI 9.7 to 17.1), respectively. In patients with posterior circulation stroke, the predictive value of the improvement at 24 hours was similar (C-statistic 0.90). CONCLUSION: Clinical improvement of patients within 24 hours of MT is a reliable and robust predictor of long-term prognosis, including patients with posterior circulation occlusions.

Susceptibility Vessel Sign in Deep Perforating Arteries in Patients with Recent Small Subcortical Infarcts.

OBJECTIVES: Recent small subcortical infarcts (RSSI) are considered an acute manifestation of cerebral small vessel disease. Paramagnetic signals in perforating arteries supplying RSSI may be detected on T2*-relaxation derived sequences on MRI and is defined as susceptibility vessel sign (SVS). We aimed to study the prevalence of SVS in patients with RSSI, and explore whether its identification is related to cerebral small vessel disease markers. MATERIALS AND METHODS: We selected patients with RSSI identified on MRI during admission from a single-center stroke registry. The main demographic and clinical features, including vascular risk factors, were collected. Radiological features of RSSI and cerebral small vessel disease [white matter hyperintensities in deep and periventricular regions, enlarged perivascular spaces, lacunae, microbleeds, and brain atrophy] were described using validated qualitative scores. The presence of SVS was assessed on T2*gradient-echo or other susceptibility-weighted imaging. We compared the clinical and radiological features of patients with or without SVS in uni- and multivariate models. RESULTS: Out of 210 patients with an RSSI on an MRI, 35 (17%) showed SVS. The proportion of SVS+ patients was similar in different susceptibility imaging modalities (p=.64). Risk factor profiles and clinical course were similar in SVS+ and SVS- patients. SVS+ patients had a higher grade of deep white matter hyperintensities and brain atrophy, more lacunae (p=.001, p=.034, p=.022, respectively), and a similar degree of the rest of radiological variables, compared to SVS- patients. In the multivariate analysis, the grade of deep white matter hyperintensities was the only independent factor associated with SVS [OR 3.1 (95% CI, 1.5-6.4)]. CONCLUSIONS: SVS in patients with RSSI is uncommon and related to a higher grade of deep white matter hyperintensities. Pathophysiological mechanisms underlying the deposition of hemosiderin in the path of occluded perforating arteries are uncertain and might include endothelial dysfunction or embolic mechanisms.

Multi-ancestry genetic study in 5,876 patients identifies an association between excitotoxic genes and early outcomes after acute ischemic stroke.

During the first hours after stroke onset neurological deficits can be highly unstable: some patients rapidly improve, while others deteriorate. This early neurological instability has a major impact on long-term outcome. Here, we aimed to determine the genetic architecture of early neurological instability measured by the difference between NIH stroke scale (NIHSS) within six hours of stroke onset and NIHSS at 24h (ΔNIHSS). A total of 5,876 individuals from seven countries (Spain, Finland, Poland, United States, Costa Rica, Mexico and Korea) were studied using a multi-ancestry meta-analyses. We found that 8.7% of ΔNIHSS variance was explained by common genetic variations, and also that early neurological instability has a different genetic architecture than that of stroke risk. Seven loci (2p25.1, 2q31.2, 2q33.3, 4q34.3, 5q33.2, 6q26 and 7p21.1) were genome-wide significant and explained 2.1% of the variability suggesting that additional variants influence early change in neurological deficits. We used functional genomics and bioinformatic annotation to identify the genes driving the association from each loci. eQTL mapping and SMR indicate that ADAM23 (log Bayes Factor (LBF)=6.34) was driving the association for 2q33.3. Gene based analyses suggested that GRIA1 (LBF=5.26), which is predominantly expressed in brain, is the gene driving the association for the 5q33.2 locus. These analyses also nominated PARK2 (LBF=5.30) and ABCB5 (LBF=5.70) for the 6q26 and 7p21.1 loci. Human brain single nuclei RNA-seq indicates that the gene expression of ADAM23 and GRIA1 is enriched in neurons. ADAM23 , a pre-synaptic protein, and GRIA1 , a protein subunit of the AMPA receptor, are part of a synaptic protein complex that modulates neuronal excitability. These data provides the first evidence in humans that excitotoxicity may contribute to early neurological instability after acute ischemic stroke. RESEARCH INTO CONTEXT: Evidence before this study: No previous genome-wide association studies have investigated the genetic architecture of early outcomes after ischemic stroke.Added Value of this study: This is the first study that investigated genetic influences on early outcomes after ischemic stroke using a genome-wide approach, revealing seven genome-wide significant loci. A unique aspect of this genetic study is the inclusion of all of the major ethnicities by recruiting from participants throughout the world. Most genetic studies to date have been limited to populations of European ancestry.Implications of all available evidence: The findings provide the first evidence that genes implicating excitotoxicity contribute to human acute ischemic stroke, and demonstrates proof of principle that GWAS of acute ischemic stroke patients can reveal mechanisms involved in ischemic brain injury.

Carotid stent occlusion after emergent stenting in acute ischemic stroke: Incidence, predictors and clinical relevance.

BACKGROUND AND AIMS: Emergent stent placement may be required during neurothrombectomy. Our aim was to investigate the incidence, predictors and clinical relevance of early extracranial carotid stent occlusion following neurothrombectomy. METHODS: We retrospectively analyzed a cohort of 761 consecutive neurothrombectomies performed at our center between May 2010 and August 2018, from whom a total of 106 patients had acute internal carotid artery occlusions. Early stent occlusion was defined as complete vessel occlusion within 24 h of neurothrombectomy. Clinical outcome was evaluated at day 90 with the modified Rankin Score scale (mRS). Pretreatment, procedural and outcome variables were recorded and analyzed using logistic regression. RESULTS: Carotid stenting was performed in 99 (13%) patients. Of those, 22 (22%) had early stent occlusion at follow-up. Stent occlusion was associated with a lower use of post-stenting angioplasty [adjusted OR (aOR) = 11.2, 95%CI = 2.49-50.78, p = 0.002)], increased residual intrastent stenosis (aOR = 2.1, 95%CI = 1.38-3.06, p < 0.001) and unsuccesful intracranial recanalization (modified TICI score 0-2a) (aOR = 13.5, 95%CI = 1.97-92.24, p = 0.008). Stent occlusion was associated with poor clinical outcome at day 90 (poorer mRS shift, aOR = 3.9, 95%CI = 1.3-11.3, p = 0.014; mRS>2, aOR = 6.3, 95%CI = 1.8-22.7, p = 0.005), and with an increased rate of symptomatic intracranial hemorrhage at 24 h (14% versus 1%, p = 0.033). CONCLUSIONS: Early carotid stent occlusion occurred in one out of five neurothrombectomies and was associated with periprocedural factors that included increased residual intrastent stenosis, a lower use of post-stenting angioplasty and unsuccessful intracranial recanalization. Further investigation is warranted for the evaluation of strategies aimed to prevent carotid stent occlusion.

Vascular Occlusion Evolution in Endovascular Reperfusion Candidates Transferred from Primary to Comprehensive Stroke Centers.

BACKGROUND: The evolution of the symptomatic intracranial occlusion during transfers from primary stroke centers (PSCs) to comprehensive stroke centers (CSCs) for endovascular treatment (EVT) is not widely known. Our aim was to identify factors related to partial or complete recanalization (REC) at CSC arrival in patients with a documented large vessel occlusion (LVO) in PSC transferred for EVT evaluation to better define the workflow at CSC of this group of patients. METHODS: We conducted an observational, multicenter study from a prospective, government-mandated, population-based registry of stroke patients with documented LVO at PSC transferred to CSC for EVT from January 2017 to June 2019. The primary end point was defined as partial or complete REC that precluded EVT at CSC arrival (REC). We evaluated the association between baseline, treatment variables and time intervals with the presence of REC. RESULTS: From 589 patients, the rate of REC at CSC was 10.5% in all LVO patients transferred from PSC to CSC for EVT evaluation. On univariate analysis, lower PSC-NIHSS (median 12vs.16, p = 0.001), tPA treatment at PSC (13.7 vs. 5.0%; p = 0.001), presence of M2 occlusion on PSC (16.8 vs. 9%; p = 0.023), and clinical improvement at CSC arrival (21.7 vs. 9.6% p = 0.001) were associated with REC at CSC. On multivariate analysis, clinical improvement at CSC arrival (p < 0.001, OR: 5.96 95% CI: 2.5-13.9) and PSC tPA treatment predicted REC (p = 0.003, OR: 4.65, 95% CI: 1.73-12.4). CONCLUSION: REC at CSC arrival occurs exceptionally in patients with a documented LVO on PSC. Repeating a second vascular study before EVT would not be necessary in most patients. Despite its modest effect, tPA treatment at PSC was an independent predictor of REC.

Elevated glucose is associated with hemorrhagic transformation after mechanical thrombectomy in acute ischemic stroke patients with severe pretreatment hypoperfusion.

Several pretreatment variables such as elevated glucose and hypoperfusion severity are related to brain hemorrhage after endovascular treatment of acute stroke. We evaluated whether elevated glucose and severe hypoperfusion have synergistic effects in the promotion of parenchymal hemorrhage (PH) after mechanical thrombectomy (MT). We included 258 patients MT-treated who had a pretreatment computed tomography perfusion (CTP) and a post-treatment follow-up MRI. Severe hypoperfusion was defined as regions with cerebral blood volume (CBV) values < 2.5% of normal brain [very-low CBV (VLCBV)-regions]. Median baseline glucose levels were 119 (IQR = 105-141) mg/dL. Thirty-nine (15%) patients had pretreatment VLCBV-regions, and 42 (16%) developed a PH after MT. In adjusted models, pretreatment glucose levels interacted significantly with VLCBV on the prediction of PH (p-interaction = 0.011). In patients with VLCBV-regions, higher glucose was significantly associated with PH (adjusted-OR = 3.15; 95% CI = 1.08-9.19, p = 0.036), whereas this association was not significant in patients without VLCBV-regions. CBV values measured at pretreatment CTP in coregistered regions that developed PH or infarct at follow-up were not correlated with pretreatment glucose levels, thus suggesting the existence of alternative deleterious mechanisms other than direct glucose-driven hemodynamic impairments. Overall, these results suggest that both severe hypoperfusion and glucose levels should be considered in the evaluation of adjunctive neuroprotective strategies.

Value of Vascular and Non-Vascular Pattern on Computed Tomography Perfusion in Patients With Acute Isolated Aphasia.

BACKGROUND AND PURPOSE: Acute onset aphasia may be due to stroke but also to other causes, which are commonly referred to as stroke mimics. We hypothesized that, in patients with acute isolated aphasia, distinct brain perfusion patterns are related to the cause and the clinical outcome. Herein, we analyzed the prognostic yield and the diagnostic usefulness of computed tomography perfusion (CTP) in patients with acute isolated aphasia. METHODS: From a single-center registry, we selected a cohort of 154 patients presenting with acute isolated aphasia who had a whole-brain CTP study available. We collected the main clinical and radiological data. We categorized brain perfusion studies on CTP into vascular and nonvascular perfusion patterns and the cause of aphasia as ischemic stroke, transient ischemic attack, stroke mimic, and undetermined cause. The primary clinical outcome was the persistence of aphasia at discharge. We analyzed the sensitivity, specificity, positive and negative predictive values of perfusion patterns to predict complete clinical recovery and ischemic stroke on follow-up imaging. RESULTS: The cause of aphasia was an ischemic stroke in 58 patients (38%), transient ischemic attack in 3 (2%), stroke mimic in 68 (44%), and undetermined in 25 (16%). CTP showed vascular and nonvascular perfusion pattern in 62 (40%) and 92 (60%) patients, respectively. Overall, complete recovery occurred in 116 patients (75%). A nonvascular perfusion pattern predicted complete recovery (sensitivity 75.9%, specificity 89.5%, positive predictive value 95.7%, and negative predictive value 54.8%), and a vascular perfusion pattern was highly predictive of ischemic stroke (sensitivity 94.8%, specificity 92.7%, positive predictive value 88.7%, and negative predictive value 96.7%). The 3 patients with ischemic stroke without a vascular perfusion pattern fully recovered at discharge. CONCLUSIONS: CTP has prognostic value in the workup of patients with acute isolated aphasia. A nonvascular pattern is associated with higher odds of full recovery and may prompt the search for alternative causes of the symptoms.

Acute Stroke Care Is at Risk in the Era of COVID-19: Experience at a Comprehensive Stroke Center in Barcelona.

BACKGROUND AND PURPOSE: The purpose of the study is to analyze how the coronavirus disease 2019 (COVID-19) pandemic affected acute stroke care in a Comprehensive Stroke Center. METHODS: On February 28, 2020, contingency plans were implemented at Hospital Clinic of Barcelona to contain the COVID-19 pandemic. Among them, the decision to refrain from reallocating the Stroke Team and Stroke Unit to the care of patients with COVID-19. From March 1 to March 31, 2020, we measured the number of emergency calls to the Emergency Medical System in Catalonia (7.5 million inhabitants), and the Stroke Codes dispatched to Hospital Clinic of Barcelona. We recorded all stroke admissions, and the adequacy of acute care measures, including the number of thrombectomies, workflow metrics, angiographic results, and clinical outcomes. Data were compared with March 2019 using parametric or nonparametric methods as appropriate. RESULTS: At Hospital Clinic of Barcelona, 1232 patients with COVID-19 were admitted in March 2020, demanding 60% of the hospital bed capacity. Relative to March 2019, the Emergency Medical System had a 330% mean increment in the number of calls (158 005 versus 679 569), but fewer Stroke Code activations (517 versus 426). Stroke admissions (108 versus 83) and the number of thrombectomies (21 versus 16) declined at Hospital Clinic of Barcelona, particularly after lockdown of the population. Younger age was found in stroke admissions during the pandemic (median [interquartile range] 69 [64-73] versus 75 [73-80] years, P=0.009). In-hospital, there were no differences in workflow metrics, angiographic results, complications, or outcomes at discharge. CONCLUSIONS: The COVID-19 pandemic reduced by a quarter the stroke admissions and thrombectomies performed at a Comprehensive Stroke Center but did not affect the quality of care metrics. During the lockdown, there was an overload of emergency calls but fewer Stroke Code activations, particularly in elderly patients. Hospital contingency plans, patient transport systems, and population-targeted alerts must act concertedly to better protect the chain of stroke care in times of pandemic.

"Incidence and Clinico-Radiological Correlations of Early Arterial Reocclusion After Successful Thrombectomy in Acute Ischemic Stroke".

About half of acute stroke patients treated with mechanical thrombectomy (MT) do not show clinical improvement despite successful recanalization. Early arterial reocclusion (EAR) may be one of the causes that explain this phenomenon. We aimed to analyze the incidence and clinico-radiological correlations of EAR after successful MT. A consecutive series of patients treated with MT between 2010 and 2018 at a single-center included in a prospective registry was retrospectively reviewed. Specific inclusion criteria for the analysis were (1) successful recanalization after MT and (2) availability of pretreatment CT perfusion and follow-up MRI. EAR was evaluated in the follow-up MR angiography. Adjusted regression models were used to analyze the association of EAR with pretreatment variables, infarct growth, final infarct volume, and clinical outcome at 90 days (ordinal distribution of the modified Rankin Scale scores). Out of 831 MT performed, 218 (26%) patients fulfilled inclusion criteria, from whom 13 (6%) suffered EAR. In multivariate analysis controlled by confounders, EAR was independently associated with poor clinical outcome (aOR = 3.2, 95%CI = 1.16-9.72, p = 0.039), greater final infarct volume (aOR = 3.8, 95%CI = 1.93-7.49, p < 0.001), and increased infarct growth (aOR = 8.5, CI95% = 2.04-34.70, p = 0.003). According to mediation analyses, the association between EAR and poor clinical outcome was mainly explained through its effects on final infarct volume and infarct growth. Additionally, EAR was associated with non-cardioembolic etiology (adjusted Odds Ratio (aOR) = 10.1, 95%CI = 1.25-81.35, p = 0.030) and longer procedural time (aOR = 2.6, 95%CI = 1.31-5.40, p = 0.007). Although uncommon, EAR hampers the benefits of successful recanalization after MT resulting in increased infarct growth and larger final lesions.

Genome-Wide Association Study of VKORC1 and CYP2C9 on acenocoumarol dose, stroke recurrence and intracranial haemorrhage in Spain.

Acenocoumarol is an oral anticoagulant with significant interindividual dose variations. Variants in CYP2C9 and VKORC1 have been associated with acenocoumarol maintenance dose. We analysed whether any of the 49 polymorphisms in CYP2C9 and VKORC1 previously associated with acenocoumarol maintenance dose in a Genome-Wide Association study (GWAs) in Dutch population are associated with stroke recurrence, intracranial haemorrhage (ICH) and acenocoumarol maintenance dose in a Spanish population. We performed a GWAs using Human Core Exome-chip (Illumina) in 78 patients stroke patients treated with acenocoumarol for secondary prevention enrolled as part of the prospective investigator-initiated study (IIS) SEDMAN Study. Patients were followed-up a median of 12.8 months. Three and eight patients had recurrent stroke and ICH events, respectively. We found 14 of the 49 published variants associated with acenocoumarol maintenance dose (p < 0.05). Six polymorphisms were associated with stroke recurrence and four variants with ICH (p < 0.05). In conclusion, variants in VKORC1 and CYP2C9 are associated with acenocoumarol maintenance dose, stroke recurrence and ICH in a Spanish cohort. These results highlight the relevance of studying pharmacogenetics associated with efficacy and safety of anticoagulant drugs and justify studies with larger sample size and different ethnic populations.