Prehospital Stroke Care Part 1: Emergency Medical Services and the Stroke Systems of Care.

Acute stroke care begins before hospital arrival, and several prehospital factors are critical in influencing overall patient care and poststroke outcomes. This topical review provides an overview of the state of the science on prehospital components of stroke systems of care and how emergency medical services systems may interact in the system to support acute stroke care. Topics include layperson recognition of stroke, prehospital transport strategies, networked stroke care, systems for data integration and real-time feedback, and inequities that exist within and among systems.

Workflow Times and Outcomes in Patients Triaged for a Suspected Severe Stroke.

INTRODUCTION: Current recommendations for regional stroke destination suggest that patients with severe acute stroke in non-urban areas should be triaged based on the estimated transport time to a referral thrombectomy-capable center. METHODS: We performed a post hoc analysis to evaluate the association of pre-hospital workflow times with neurological outcomes in patients included in the RACECAT trial. Workflow times evaluated were known or could be estimated before transport allocation. Primary outcome was the shift analysis on the modified Rankin score at 90 days. RESULTS: Among the 1,369 patients included, the median time from onset to emergency medical service (EMS) evaluation, the estimated transport time to a thrombectomy-capable center and local stroke center, and the estimated transfer time between centers were 65 minutes (interquartile ratio [IQR] = 43-138), 61 minutes (IQR = 36-80), 17 minutes (IQR = 9-27), and 62 minutes (IQR = 36-73), respectively. Longer time intervals from stroke onset to EMS evaluation were associated with higher odds of disability at 90 days in the local stroke center group (adjusted common odds ratio (acOR) for each 30-minute increment = 1.03, 95% confidence interval [CI] = 1.01-1.06), with no association in the thrombectomy-capable center group (acOR for each 30-minute increment = 1.01, 95% CI = 0.98-1.01, pinteraction  = 0.021). No significant interaction was found for other pre-hospital workflow times. In patients evaluated by EMS later than 120 minutes after stroke onset, direct transport to a thrombectomy-capable center was associated with better disability outcomes (acOR = 1.49, 95% CI = 1.03-2.17). CONCLUSION: We found a significant heterogeneity in the association between initial transport destination and neurological outcomes according to the elapse of time between the stroke onset and the EMS evaluation (ClinicalTrials.gov: NCT02795962). ANN NEUROL 2022;92:931-942.

Thrombectomy versus Medical Management in Mild Strokes due to Large Vessel Occlusion: Exploratory Analysis from the EXTEND-IA Trials and a Pooled International Cohort.

OBJECTIVE: This study was undertaken to evaluate functional and safety outcomes for endovascular thrombectomy (EVT) versus medical management (MM) in patients with large vessel occlusion (LVO) and mild neurological deficits, stratified by perfusion imaging mismatch. METHODS: The pooled cohort consisted of patients with National Institutes of Health Stroke Scale (NIHSS) < 6 and internal carotid artery (ICA), M1, or M2 occlusions from the Extending the Time for Thrombolysis in Emergecy Neurological Deficits - Intra-Arterial (EXTEND-IA) Trial,  Tenecteplase vs Alteplase before Endovascular Thrombectomy in Ischemic Stroke (EXTEND-IA TNK) trials Part I/II and prospective data from 15 EVT centers from October 2010 to April 2020. RAPID software estimated ischemic core and mismatch. Patients receiving primary EVT (EVTpri ) were compared to those who received primary MM (MMpri ), including those who deteriorated and received rescue EVT, in overall and propensity score (PS)-matched cohorts. Patients were stratified by target mismatch (mismatch ratio ≥ 1.8 and mismatch volume ≥ 15ml). Primary outcome was functional independence (90-day modified Rankin Scale = 0-2). Secondary outcomes included safety (symptomatic intracerebral hemorrhage [sICH], neurological worsening, and mortality). RESULTS: Of 540 patients, 286 (53%) received EVTpri and demonstrated larger critically hypoperfused tissue (Tmax > 6 seconds) volumes (median [IQR]: 64 [26-96] ml vs MMpri : 40 [14-76] ml, p < 0.001) and higher presentation NIHSS (median [IQR]: 4 [2-5] vs MMpri : 3 [2-4], p < 0.001). Functional independence was similar (EVTpri : 77.4% vs MMpri : 75.6%, adjusted odds ratio [aOR] = 1.29, 95% confidence interval [CI] = 0.82-2.03, p = 0.27). EVT had worse safety regarding sICH (EVTpri : 16.3% vs MMpri : 1.3%, p < 0.001) and neurological worsening (EVTpri : 19.6% vs MMpri : 6.7%, p < 0.001). In 414 subjects (76.7%) with target mismatch, EVT was associated with improved functional independence (EVTpri : 77.4% vs MMpri : 72.7%, aOR = 1.68, 95% CI = 1.01-2.81, p = 0.048), whereas there was a trend toward less favorable outcomes with primary EVT (EVTpri : 77.4% vs MMpri : 83.3%, aOR = 0.39, 95% CI = 0.12-1.34, p = 0.13) without target mismatch (pinteraction  = 0.06). Similar findings were observed in a propensity score-matched subpopulation. INTERPRETATION: Overall, EVT was not associated with improved clinical outcomes in mild strokes due to LVO, and sICH was increased. However, in patients with target mismatch profile, EVT was associated with increased functional independence. Perfusion imaging may be helpful to select mild stroke patients for EVT. ANN NEUROL 2022;92:364-378.

The Role of Vascular Imaging atReferral Centers in the Drip and Ship Paradigm.

BACKGROUND: In drip-and-ship protocols, non-invasive vascular imaging (NIVI) at Referral Centers (RC), although recommended, is not consistently performed and its value is uncertain. We evaluated the role of NIVI at RC, comparing patients with (VI+) and without (VI-) vascular imaging in several outcomes. METHODS: Observational, multicenter study from a prospective government-mandated population-based registry of code stroke patients. We selected acute ischemic stroke patients, initially assessed at RC from January-2016 to June-2020. We compared and analyzed the rates of patients transferred to a Comprehensive Stroke Center (CSC) for Endovascular Treatment (EVT), rates of EVT and workflow times between VI+ and VI- patients. RESULTS: From 5128 ischemic code stroke patients admitted at RC; 3067 (59.8%) were VI+, 1822 (35.5%) were secondarily transferred to a CSC and 600 (11.7%) received EVT. Among all patients with severe stroke (NIHSS ≥16) at RC, a multivariate analysis showed that lower age, thrombolytic treatment, and VI+ (OR:1.479, CI95%: 1.117-1.960, p=0.006) were independent factors associated to EVT. The rate of secondary transfer to a CSC was lower in VI+ group (24.6% vs. 51.6%, p<0.001). Among transferred patients, EVT was more frequent in VI+ than VI- (48.6% vs. 21.7%, p<0.001). Interval times as door-in door-out (median-minutes 83.5 vs. 82, p= 0.13) and RC-Door to puncture (median-minutes 189 vs. 178, p= 0.47) did not show differences between both groups. CONCLUSION: In the present study, NIVI at RC improves selection for EVT, and is associated with receiving EVT in severe stroke patients. Time-metrics related to drip-and-ship model were not affected by NIVI.

Reasons for Not Performing Mechanical Thrombectomy: A Population-Based Study of Stroke Codes.

Background and Purpose: Mechanical thrombectomy (MT) is effective for acute ischemic stroke (AIS) in selected patients with large intracranial vessel occlusion. A minority of patients with AIS receive MT. We aimed to describe the reasons for excluding patients with AIS for MT. Methods: We evaluated patients with AIS in a prospective population-based multicenter registry (Codi Ictus Catalunya registry) that includes all stroke code activations from January to June 2018 in Catalonia, Spain. We analyzed the major reasons for not treating with MT. Results: Stroke code was activated in 3060 patients. Excluding 355 intracranial hemorrhages and 502 stroke mimics, resulted in 2203 patients with AIS (mean age 72.8±13.8 years; 44.6% were women). Of the patients with AIS, 405 (18.4%) were treated with MT. We analyzed the reasons for not treating with MT. The following reasons were considered not modifiable: absence of large intracranial vessel occlusion (922, 41.9%), transient ischemic attack (206, 9.4%), and more than one cause (124, 5.6%). The potentially modifiable reasons for not performing MT by changing selection criteria were as follows: an intracranial artery occlusion that was considered inaccessible or not indicated (48, 2.2%); clinical presentation that was considered too mild to be treated (222, 10.1%); neuroimaging criteria (129, 5.9%), age/prior modified Rankin Scale score/medical comorbidities (129, 5.9%), and therapeutic time window >8 hours (16, 0.7%). Conclusions: In our area, considering all potentially modifiable causes for not performing MT, the percentage of patients with AIS eligible for MT could increase from 18.4% to a maximum of 43.1%. The clinical benefit of this increase is still uncertain and should be confirmed in future trials. Criteria for stroke code activation must be considered for the generalizability of these results.

Reported Prestroke Physical Activity Is Associated with Vascular Endothelial Growth Factor Expression and Good Outcomes after Stroke.

INTRODUCTION: Physical activity (PhA) prior to stroke has been associated with good outcomes after the ischemic insult, but there is scarce data on the involved molecular mechanisms. METHODS: We studied consecutive acute ischemic stroke patients admitted to a single tertiary stroke center. Prestroke PhA was evaluated with the International Physical Activity Questionnaire (metabolic equivalent of minutes/week). We studied several circulating angiogenic and neurogenic factors at different time points: vascular endothelial growth factor (VEGF), granulocyte colony-stimulating factor (G-CSF), and brain-derived neurotrophic factor (BDNF) at admission, day 7, and at 3 months. We considered good functional outcome at 3 months (modified Rankin scale ≤ 2) as primary end point, and final infarct volume as secondary outcome. RESULTS: We studied 83 patients with at least 2 time point serum determinations (mean age 69.6 years, median National Institutes of Health Stroke Scale 17 at admission). Patients more physically active before stroke had a significantly higher increment of serum VEGF on the seventh day when compared to less active patients. This increment was an independent predictor of good functional outcome at 3 months and was associated with smaller infarct volume in multivariate analyses adjusted for relevant covariates. We did not find independent associations of G-CSF or BDNF levels neither with level of prestroke PhA nor with stroke outcomes. CONCLUSIONS: Although there are probably more molecular mechanisms by which PhA exerts its beneficial effects in stroke outcomes, our observation regarding the potential role of VEGF is plausible and in line with previous experimental studies. Further research in this field is needed.

Prognostic value of plasma ß-amyloid levels in patients with acute intracerebral hemorrhage.

BACKGROUND AND PURPOSE: It has been proposed that the deposition of the ß-amyloid peptide (Aß) in the brain parenchyma and brain blood vessels has deleterious effects. We tested the hypothesis that the levels of plasma Aß are related to the outcome in patients with intracerebral hemorrhage. METHODS: In a multicenter study, we prospectively included patients with spontaneous intracerebral hemorrhage within the first 24 hours after onset. At admission, we measured plasma Aß40 and Aß42 levels using ELISA techniques. Also, we recorded age, sex, vascular risk factors, National Institutes of Health Stroke Scale score, presence of intraventricular hemorrhage, localization, cause, and volume of the hematoma. We obtained the modified Rankin scale and defined a unfavorable outcome as modified Rankin scale >2 at 3 months. Bivariate and multivariate regression analyses were performed. RESULTS: We studied 160 patients (mean age, 73.8±11.3 years; 59.4% of them were men). A favorable outcome was observed in 64 (40%) of the patients. In the bivariate analyses, unfavorable outcome was associated with high age, female sex, diabetes mellitus, presence of intraventricular hemorrhage, high blood glucose, high National Institutes of Health Stroke Scale score, high volume, and high plasma levels of Aß42 and Aß40. The multivariate analysis showed that increased age (odds ratio, 1.07; 95% confidence interval, 1.035-1.21; P<0.0001), high admission National Institutes of Health Stroke Scale score (odds ratio, 1.29, 95% confidence interval, 1.17-1.42; P<0.0001), presence of diabetes mellitus (odds ratio, 4.15; 95% confidence interval, 1.21-14.1; P=0.02), and Aß42 levels >9.7 pg/mL (odds ratio, 4.11; 95% confidence interval, 1.65-10.1; P=0.02) were independently associated with an increased likelihood of an unfavorable outcome. CONCLUSIONS: High levels of plasma Aß42 in patients with acute intracerebral hemorrhage are associated with a poor functional prognosis.

Influence of Hospital Type on Outcomes of Patients With Acute Spontaneous Intracerebral Hemorrhage: A Population-Based Study.

BACKGROUND AND OBJECTIVES: Whether the outcome of patients with spontaneous intracerebral hemorrhage (ICH) differs depending on the type of hospital where they are admitted is uncertain. The objective of this study was to determine influence of hospital type at admission (telestroke center [TSC], primary stroke center [PSC], or comprehensive stroke center [CSC]) on outcome for patients with ICH. We hypothesized that outcomes may be better for patients admitted to a CSC. METHODS: This is a multicenter prospective observational and population-based study of a cohort of consecutively recruited patients with ICH (March 2020-March 2022). We included all patients with spontaneous ICH in Catalonia (Spain) who had a pre-ICH modified Rankin scale (mRS) score of 0-3 and who were admitted to the hospital within 24 hours of onset. We compared patients admitted to a TSC/PSC (n = 641) or a CSC (n = 1,320) and also analyzed the subgroup of patients transferred (n = 331) or not transferred (n = 310) from a TSC/PSC to a CSC. The main outcome was the 3-month mRS score obtained by blinded investigators. Outcomes were compared using adjusted ordinal logistic regression to estimate the common odds ratio (OR) and 95% CI for a shift in mRS scores. A propensity score matching (PSM) analysis was performed for the subgroup of transferred patients. RESULTS: Relevant data were obtained from 1961 of a total of 2,230 patients, with the mean (SD) age of 70 (14.1) years, and 713 (38%) patients were women. After adjusting for confounders (age, NIH Stroke Scale score, intraventricular hemorrhage, hematoma volume, and pre-ICH mRS score), type of hospital of initial admission (CSC vs TSC/PSC) was not associated with outcome (adjusted common OR 1.13, 95% CI 0.93-1.38). A PSM analysis indicated that transfer to a CSC was not associated with more favorable outcomes (OR 0.77, 95% CI 0.55-1.10; p = 0.16). DISCUSSION: In this population-based study, we found that, after adjusting for confounders, hospital types were not associated with functional outcomes. In addition, for patients who were transferred from a TSC/PSC to a CSC, PSM indicated that outcomes were similar to nontransferred patients. Our findings suggest that patient characteristics are more important than hospital characteristics in determining outcome after ICH. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov Identifier: NCT03956485.

Recurrent transient ischaemic attack and early risk of stroke: data from the PROMAPA study.

BACKGROUND: Many guidelines recommend urgent intervention for patients with two or more transient ischaemic attacks (TIAs) within 7 days (multiple TIAs) to reduce the early risk of stroke. OBJECTIVE: To determine whether all patients with multiple TIAs have the same high early risk of stroke. METHODS: Between April 2008 and December 2009, we included 1255 consecutive patients with a TIA from 30 Spanish stroke centres (PROMAPA study). We prospectively recorded clinical characteristics. We also determined the short-term risk of stroke (at 7 and 90 days). Aetiology was categorised using the TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification. RESULTS: Clinical variables and extracranial vascular imaging were available and assessed in 1137/1255 (90.6%) patients. 7-Day and 90-day stroke risk were 2.6% and 3.8%, respectively. Large-artery atherosclerosis (LAA) was confirmed in 190 (16.7%) patients. Multiple TIAs were seen in 274 (24.1%) patients. Duration <1 h (OR=2.97, 95% CI 2.20 to 4.01, p<0.001), LAA (OR=1.92, 95% CI 1.35 to 2.72, p<0.001) and motor weakness (OR=1.37, 95% CI 1.03 to 1.81, p=0.031) were independent predictors of multiple TIAs. The subsequent risk of stroke in these patients at 7 and 90 days was significantly higher than the risk after a single TIA (5.9% vs 1.5%, p<0.001 and 6.8% vs 3.0%, respectively). In the logistic regression model, among patients with multiple TIAs, no variables remained as independent predictors of stroke recurrence. CONCLUSIONS: According to our results, multiple TIAs within 7 days are associated with a greater subsequent risk of stroke than after a single TIA. Nevertheless, we found no independent predictor of stroke recurrence among these patients.

Hemorrhagic risk of emergent endovascular treatment plus stenting in patients with acute ischemic stroke.

BACKGROUND: Several endovascular revascularization strategies have been described for the treatment of acute ischemic stroke (AIS). One of them is stenting when a very narrow stenosis with high reocclusion risk remains after recanalization. This study describes the risk of symptomatic intracerebral hemorrhage (SICH) after emergent stenting in patients with AIS treated with endovascular therapies. METHODS: Consecutive patients who underwent endovascular treatment over a 37-month period were retrospectively analyzed. Patients were classified in 2 groups: (1) patients in whom a stent was deployed; and (2) patients without stenting. Double antiplatelet treatment with aspirin and clopidogrel was administered at the time of stenting. SICH was defined as any hemorrhagic transformation with National Institutes of Health Stroke Scale (NIHSS) score worsening 4 points or more (European-Australasian Acute Stroke Study II criteria). RESULTS: A total of 143 patients were included (mean age: 66.1±11.7 years, median NIHSS score: 18). Acute phase stenting was performed in 24 subjects (16.8%): 4 intracranial (3 in basilar artery, 1 in middle cerebral artery) and 20 extracranial (internal carotid artery). SICH occurred in 11 patients, 5 of 24 (20.8%) in patients with stenting and in 3 of 119 (2.5%) without (P=.008). No differences were found with respect to baseline NIHSS score or intravenous tissue plasminogen activator administration. Acute phase stenting emerged as an independent predictor of SICH after adjustment for potential confounders and procedure duration: odds ratio 7.3 (confidence interval 1.4-36.8, P=.016). CONCLUSIONS: Our findings suggest that emergent stenting in endovascular treatment of AIS is associated with SICH.

Usefulness of material recovered from distal embolic protection devices after carotid angioplasty for proteomic studies.

PURPOSE: To demonstrate the usefulness of biologic material obtained from distal embolic protection devices (DEPDs) used in carotid angioplasty for the study of atherosclerosis protein markers and to establish the effect of systemic inflammation on the protein expression of carotid atheromatous plaques. MATERIALS AND METHODS: Two-dimensional gel electrophoresis and mass spectrometry were used to study proteins obtained from debris captured in DEPDs from patients who underwent carotid angioplasty. In addition, protein expression obtained from angioplasty samples in patients with different types of systemic inflammation (measured by serum levels of high-sensitivity C-reactive protein [CRP] with a cutoff value of 3 mg/L) was compared. Finally, immunohistochemistry of atherosclerotic plaques obtained by endarterectomy was used to validate the results obtained using DEPDs. RESULTS: Proteomic studies were successfully performed using debris from DEPDs. Protein expression differences were found in debris from patients with high systemic inflammation compared with debris from patients with low systemic inflammation. Annexin A5 (ANXA5), haptoglobin precursor, purine nucleoside phosphorylase, transgelin-2 (TAGLN2), and bisphosphoglycerate mutase were upregulated in debris from patients with high systemic inflammation, and proteasome subunit 8 beta type and glutathione-S-transferase kappa 1 (GSTK1) levels were higher in debris from patients with low levels of systemic inflammation. CONCLUSIONS: Atherosclerotic plaque debris captured in DEPDs is a suitable and valid source of material for proteomic studies of atherosclerosis. Protein expression in DEPD debris is affected by systemic inflammation.

European Stroke Organisation (ESO) guidelines on intravenous thrombolysis for acute ischaemic stroke.

Intravenous thrombolysis is the only approved systemic reperfusion treatment for patients with acute ischaemic stroke. These European Stroke Organisation (ESO) guidelines provide evidence-based recommendations to assist physicians in their clinical decisions with regard to intravenous thrombolysis for acute ischaemic stroke. These guidelines were developed based on the ESO standard operating procedure and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. The working group identified relevant clinical questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and wrote recommendations. Expert consensus statements were provided if not enough evidence was available to provide recommendations based on the GRADE approach. We found high quality evidence to recommend intravenous thrombolysis with alteplase to improve functional outcome in patients with acute ischemic stroke within 4.5 h after symptom onset. We also found high quality evidence to recommend intravenous thrombolysis with alteplase in patients with acute ischaemic stroke on awakening from sleep, who were last seen well more than 4.5 h earlier, who have MRI DWI-FLAIR mismatch, and for whom mechanical thrombectomy is not planned. These guidelines provide further recommendations regarding patient subgroups, late time windows, imaging selection strategies, relative and absolute contraindications to alteplase, and tenecteplase. Intravenous thrombolysis remains a cornerstone of acute stroke management. Appropriate patient selection and timely treatment are crucial. Further randomized controlled clinical trials are needed to inform clinical decision-making with regard to tenecteplase and the use of intravenous thrombolysis before mechanical thrombectomy in patients with large vessel occlusion.

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.

Association of High Serum Levels of Growth Factors with Good Outcome in Ischemic Stroke: a Multicenter Study.

The main objective of this research work was to study the association of serum levels of growth factors (GF) and SDF-1α with the functional outcome and reduction of lesion volume in ischemic stroke patients. In this multicenter study, 552 patients with non-lacunar stroke (male, 62.1%; mean age, 68.2 ± 11.4) were included within 24 h from symptom onset. The main outcome variable was good functional outcome (modified Rankin Scale [mRS] ≤ 2) at 12 months. Secondary outcome variable was infarct volume (in mL) after 6 ± 3 months. Serum levels of VEGF, Ang-1, G-CSF, BDNF, and SDF-1α were measured by ELISA at admission, 7 ± 1 days, at 3 ± 1 months, and 12 ± 3 months. Except for BDNF, all GF and SDF-1α serum levels showed a peak value at day 7 and remained elevated during the first 3 months (all p < 0.01). High serum levels at day 7 of VEGF (OR, 19.3), Ang-1 (OR, 14.7), G-CSF (OR, 9.6), and SDF-1α (OR, 28.5) were independently associated with good outcome at 12 months (all p < 0.0001). On the other hand, serum levels of VEGF (B, - 21.4), G-CSF (B, - 14.0), Ang-1 (B, - 13.3), and SDF-1α (B, - 44.6) measured at day 7 were independently associated with lesion volume at 6 months (p < 0.01). In summary, high serum levels of VEGF, Ang-1, G-CSF, and SDF-1α at day 7 and 3 months after ischemic stroke are associated with good functional outcome and smaller residual lesion at 1 year of follow-up.

Simvastatin reduces the association of NMDA receptors to lipid rafts: a cholesterol-mediated effect in neuroprotection.

BACKGROUND AND PURPOSE: Excess brain extracellular glutamate induced by cerebral ischemia leads to neuronal death, mainly through overactivation of N-methyl-D-aspartate (NMDA) receptors. The cholesterol-lowering drugs statins have been reported to protect from NMDA-induced neuronal death but, so far, the mechanism underlying this protection remains unclear. Because NMDA receptors have been reported to be associated with the cholesterol-rich membrane domains known as lipid rafts, we have investigated the effect of treatments that deplete cholesterol levels on excitotoxicity and on association of NMDA receptors to lipid rafts. METHODS: Primary neuronal cultures were pretreated with inhibitors of cholesterol synthesis and cholesterol, and NMDA-induced cell death was determined by measuring release of lactate dehydrogenase. Lipid raft fractions were isolated and Western blots were performed. RESULTS: Treatment with the inhibitors of cholesterol synthesis simvastatin, which inhibits the first step of cholesterol synthesis, or AY9944, which inhibits the last step of cholesterol synthesis, protected neurons from NMDA-induced neuronal death by 70% and 54%, respectively. Treatment with these compounds reduced neuronal cholesterol levels by 35% and 13%, respectively. Simvastatin and AY9944 reduced the association of the subunit 1 of NMDA receptors (NMDAR1) to lipid rafts by 42% and 21%, respectively, and did not change total expression of NMDAR1. Addition of cholesterol reduced neuroprotection by statins and AY9944, and partially reverted the effect of simvastatin on the association of NMDAR1 to lipid rafts. CONCLUSIONS: These data demonstrate that reduction of cholesterol levels protects from NMDA-induced neuronal damage probably by reducing the association of NMDA receptors to lipid rafts.

Biological signatures of brain damage associated with high serum ferritin levels in patients with acute ischemic stroke and thrombolytic treatment.

BACKGROUND AND PURPOSE: Increased body iron stores have been related to greater oxidative stress and brain injury in clinical and experimental cerebral ischemia and reperfusion. We aimed to investigate the biological signatures of excitotoxicity, inflammation and blood brain barrier disruption potentially associated with high serum ferritin levels-related damage in acute stroke patients treated with i.v. t-PA. METHODS: Serum levels of ferritin (as index of increased cellular iron stores), glutamate, interleukin-6, matrix metalloproteinase-9 and cellular fibronectin were determined in 134 patients treated with i.v. t-PA within 3 hours from stroke onset in blood samples obtained before t-PA treatment, at 24 and 72 hours. RESULTS: Serum ferritin levels before t-PA infusion correlated to glutamate (r = 0.59, p < 0.001) and interleukin-6 (r = 0.55, p < 0.001) levels at baseline, and with glutamate (r = 0.57, p < 0.001), interleukin-6 (r = 0.49, p < 0.001), metalloproteinase-9 (r = 0.23, p = 0.007) and cellular fibronectin (r = 0.27, p = 0.002) levels measured at 24 hours and glutamate (r = 0.415, p < 0.001), interleukin-6 (r = 0.359, p < 0.001) and metalloproteinase-9 (r = 0.261, p = 0.004) at 72 hours. The association between ferritin and glutamate levels remained after adjustment for confounding factors in generalized linear models. CONCLUSIONS: Brain damage associated with increased iron stores in acute ischemic stroke patients treated with iv. tPA may be mediated by mechanisms linked to excitotoxic damage. The role of inflammation, blood brain barrier disruption and oxidative stress in this condition needs further research.

Effect of general anaesthesia on functional outcome in patients with anterior circulation ischaemic stroke having endovascular thrombectomy versus standard care: a meta-analysis of individual patient data.

BACKGROUND: General anaesthesia (GA) during endovascular thrombectomy has been associated with worse patient outcomes in observational studies compared with patients treated without GA. We assessed functional outcome in ischaemic stroke patients with large vessel anterior circulation occlusion undergoing endovascular thrombectomy under GA, versus thrombectomy not under GA (with or without sedation) versus standard care (ie, no thrombectomy), stratified by the use of GA versus standard care. METHODS: For this meta-analysis, patient-level data were pooled from all patients included in randomised trials in PuMed published between Jan 1, 2010, and May 31, 2017, that compared endovascular thrombectomy predominantly done with stent retrievers with standard care in anterior circulation ischaemic stroke patients (HERMES Collaboration). The primary outcome was functional outcome assessed by ordinal analysis of the modified Rankin scale (mRS) at 90 days in the GA and non-GA subgroups of patients treated with endovascular therapy versus those patients treated with standard care, adjusted for baseline prognostic variables. To account for between-trial variance we used mixed-effects modelling with a random effect for trials incorporated in all models. Bias was assessed using the Cochrane method. The meta-analysis was prospectively designed, but not registered. FINDINGS: Seven trials were identified by our search; of 1764 patients included in these trials, 871 were allocated to endovascular thrombectomy and 893 were assigned standard care. After exclusion of 74 patients (72 did not undergo the procedure and two had missing data on anaesthetic strategy), 236 (30%) of 797 patients who had endovascular procedures were treated under GA. At baseline, patients receiving GA were younger and had a shorter delay between stroke onset and randomisation but they had similar pre-treatment clinical severity compared with patients who did not have GA. Endovascular thrombectomy improved functional outcome at 3 months both in patients who had GA (adjusted common odds ratio (cOR) 1·52, 95% CI 1·09-2·11, p=0·014) and in those who did not have GA (adjusted cOR 2·33, 95% CI 1·75-3·10, p<0·0001) versus standard care. However, outcomes were significantly better for patients who did not receive GA versus those who received GA (covariate-adjusted cOR 1·53, 95% CI 1·14-2·04, p=0·0044). The risk of bias and variability between studies was assessed to be low. INTERPRETATION: Worse outcomes after endovascular thrombectomy were associated with GA, after adjustment for baseline prognostic variables. These data support avoidance of GA whenever possible. The procedure did, however, remain effective versus standard care in patients treated under GA, indicating that treatment should not be withheld in those who require anaesthesia for medical reasons. FUNDING: Medtronic.

Geographic dissemination of endovascular stroke thrombectomy in Catalonia within the 2011-2015 period.

INTRODUCTION: Endovascular thrombectomy was recently established as a new standard of care in acute ischemic stroke patients with large artery occlusions. Using small area health statistics, we sought to assess dissemination of endovascular thrombectomy in Catalonia throughout the period 2011-2015. PATIENTS AND METHODS: We used registry data to identify all endovascular thrombectomies for acute ischemic stroke performed in Catalonia within the study period. The SONIIA registry is a government-mandated, population-based and externally audited data base that includes all reperfusion therapies for acute ischemic stroke. We linked endovascular thrombectomy cases identified in the registry with the Central Registry of the Catalan Public Health Insurance to obtain the primary care service area of residence for each treated patient, age and sex. We calculated age-sex standardized endovascular thrombectomy rates over time according to different territorial segmentation patterns (metropolitan/provincial rings and primary care service areas). RESULTS: Region-wide age-sex standardized endovascular thrombectomy rates increased significantly from 3.9 × 100,000 (95% confidence interval: 3.4-4.4) in 2011 to 6.8 × 100,000 (95% confidence interval: 6.2-7.6) in 2015. Such increase occurred in inner and outer metropolitan rings as well as provinces although highest endovascular thrombectomy rates were persistently seen in the inner metropolitan area. Changes in endovascular thrombectomy access across primary care service areas over time were more subtle, but there was a rather generalized increase of standardized endovascular thrombectomy rates. DISCUSSION: This study demonstrates temporal and territorial dissemination of access to endovascular thrombectomy in Catalonia over a 5-year period although variation remains at the completion of the study. CONCLUSION: Mapping of endovascular thrombectomy is essential to assess equity and propose actions for access dissemination.

The natural tissue plasminogen activator inhibitor neuroserpin and acute ischaemic stroke outcome.

Neuroserpin is a brain-derived natural inhibitor of tissue plasminogen activator (tPA) that has shown neuroprotective effects in animal models of brain ischaemia. Our aim was to investigate the association of neuroserpin levels in blood with functional outcome in patients with acute ischaemic stroke. Due to the potential effect of tPA treatment interfering on neuroserpin levels, we studied two different cohorts: 129 patients not treated with tPA and 80 patients treated with intravenous tPA within 3 hours (h) from symptoms onset. Neuroserpin levels were measured by ELISA. Good functional outcome at three months was defined as Rankin scale score ≤2. In the two cohorts, serum neuroserpin levels on admission were significantly higher than at 24 h, 72 h and in healthy subjects. In non tPA-treated patients, neuroserpin levels decrease at 24 h, but not levels at baseline, were associated with good outcome (for each quartile decrease, adjusted odds ratio [OR] 15.0; 95% confidence interval [CI], 3.5 to 66). In the tPA-treated cohort, high neuroserpin levels before tPA bolus had the stronger effect on favourable outcome (for each quartile, OR 13.5; 95%CI, 3.9 to 47). Furthermore, for each quartile in neuroserpin levels before tPA bolus there was a 80% (95%CI, 48 to 92) reduction in the probability of subsequent parenchymal haematoma. In summary, high serum neuroserpin levels before intravenous tPA and neuroserpin levels decrease at 24 h after ischaemic stroke, independently of tPA treatment, are associated with good functional outcome. These findings support the concept that neuroserpin might play an important role during cerebral ischaemia.

High serum levels of pro-brain natriuretic peptide (pro BNP) identify cardioembolic origin in undetermined stroke.

BACKGROUND: Stroke subtype diagnosis leads to specific therapies to reduce recurrences. Because nearly one third of patients remain with unknown etiology after a complete screening workup, we aim to investigate whether molecular markers of myocardial damage were associated with cardioembolic stroke and if they were useful to reclassify strokes of undetermined etiology. METHODS: We included 262 patients with first ischemic stroke within the first 12 hours. Stroke subtype was evaluated by TOAST criteria. Stroke of undetermined origin were reclassified into likely atherothrombotic or likely cardioembolic according to a predefined non-validated algorithm. Blood samples were obtained on admission to determine serum levels of molecular markers (pro-BNP, pro-ANP and CK-MB) of myocardial damage. RESULTS: Patients with cardioembolic infarct showed higher levels of pro-BNP, pro-ANP and CK-MB. Pro-BNP > 360 pg/mL was independently associated with cardioembolic stroke (OR: 28.51, CI95%: 5.90-136.75, p< 0.0001). Stroke etiology was undetermined in 82 patients (31%); 34 were reclassified as likely cardioembolic, 22 as likely atherothrombotic, and 26 remained as undetermined. Pro-BNP > 360 pg/mL was the only factor independently associated with likely cardioembolic stroke. CONCLUSIONS: Pro-BNP levels higher than 360 pg/mL are associated with cardioembolic stroke and may be useful to reclassify undetermined strokes as of cardioembolic origin.