Risultati per: Sindromi coronariche acute

Stroke, Volume 53, Issue Suppl_1, Page AWP249-AWP249, February 1, 2022. Background:Acute hyperglycemia occurs in over 40% of ischemic stroke patients, increases hemorrhagic transformation (HT) and worsens stroke outcome. Previous rodent studies reported deleterious effects of hyperglycemia on stroke outcome during acute stroke (within hours to days), however, its impact during subacute stroke period (days to weeks) remains unclear. Moreover, the mechanisms underlying hyperglycemia’s worsening of stroke outcomes remains elusive. In this study, we investigated the effect of acute hyperglycemia on immune responses and stroke outcome in acute and subacute phases.Method:Male C57/BL6 mice were subjected to middle cerebral artery occlusion (MCAO) for 30 min, followed by reperfusion to mimic ischemic stroke. Acute hyperglycemia was induced by glucose injection 10 min before MCAO. For the acute phase study, mice were sacrificed at 4.5 hrs to assess blood-brain barrier leakage (Evans blue) and brain immune cell populations (flow cytometry), and at 24 hrs to evaluate brain infarct, swelling and HT. In the sub-acute phase, mice were allowed to survive 14 days after stroke to evaluate mortality rate, neurological deficit, and motor-sensory dysfunction using a rotating beam test.Result:In the acute phase, hyperglycemia rapidly increased BBB leakage by 4.5 hrs after stroke, when compared to the normoglycemia group (p

Stroke, Volume 53, Issue Suppl_1, Page ATP6-ATP6, February 1, 2022. Background:Thrombolysis remains underutilized for acute ischemic stroke (AIS) in healthcare systems in low- and middle-income countries.Aims:We aimed to investigate the factors associated with utilization of intravenous thrombolysis in an academic medical center in Lebanon.Methods:Patients presenting to a tertiary medical center in Lebanon between January 2015 and October 2019 were reviewed. Inclusion criteria were age greater than 18 years and presenting to the emergency department within 48 hours from last known well. Patient, disease, and health system response characteristics were collected and those eligible for and those who received thrombolysis within 4.5 hours onset by guidelines criteria were identified by chart review. Descriptive statistics, bivariate and multivariate analyses were performed for association with thrombolysis administration.Results:Of 373 AIS patients presenting within 48 hours of onset to the hospital, 65 (17.4%) were deemed to be candidates for thrombolysis. Forty (61.5% of eligible) received thrombolysis. Those receiving thrombolysis compared to eligible but not receiving thrombolysis were younger (median 72 vs 86, p=0.018), had higher NIHSS (median 11.5 vs 7, p=0.032), had greater likelihood of stroke code activation (79% vs 41%, p=0.011), and no anti-platelet use (22.5% vs 56%, p=0.021). The multivariate analysis showed that thrombolysis among eligible patients associated with younger age (OR 1.05 [1.01-1.10], p=0.029), a higher NIHSS (OR 1.12 [1.01-1.25], p=0.041), and stroke code activation (OR 2.81 [1.16-6.81], P=0.022).Conclusion:A good proportion of eligible AIS patients did not receive thrombolysis. To increase thrombolysis use in low- and middle-income countries, more consistent stroke code activation and education on age and stroke severity in eligibility are needed.

Stroke, Volume 53, Issue Suppl_1, Page ATP192-ATP192, February 1, 2022. Background:Adrenomedullin (AM), an endogenous peptide, is secreted in response to cerebral ischemia, contributing to neuroprotection by exerting anti-inflammatory and vasodilatory effects. Although previous studies showed elevated levels of mid-regional fragment of pro-AM (MR-proAM), a stable marker of AM, predict unfavorable outcome in acute ischemic stroke (AIS), the role of the biomarker remains to be determined.Methods:Firstly, plasma MR-proAM levels were measured in consecutively enrolled patients with AIS within 4.5 hours of the onset and compared with those of healthy controls. Propensity score was used to match the baseline difference. Secondly, variables associated with the increased MR-proAM levels were evaluated in AIS. Finally, it was determined whether MR-proAM levels are associated with a large penumbra which was defined as ICA/M1 occlusion with NIH stroke scale ≥ 6 and ischemic core volume ≤ 50 ml calculated by the RAPID software.Results:MR-proAM levels in AIS (n = 122; median age, 77 years; male, 59%; median NIHSS 6.5) were higher (median 0.68 vs. 0.42 nmol/L, p < 0.001) compared with controls (n = 1298; median age, 58 years; male, 33%). The difference remained after matching of baseline (p=0.004). In patients with AIS, MR-proAM levels were correlated with NIHSS (r = 0.367, p < 0.001) and eGFR (r = -0.527, p < 0.001). MR-proAM levels did not correlate with ischemic core volume (r = 0.065, p = 0.478), but significantly increased in AIS patients with cardioembolic stroke (CES) (n = 53) (0.80 vs. 0.59 nmol/L, p < 0.001) and ICA/M1 occlusion (n = 40) (0.78 vs. 0.63 nmol/L, p = 0.048). Interestingly, MR-proAM levels were higher (0.85 vs. 0.62, p < 0.001) in AIS patients with a large penumbra (n = 24) compared to those without (n = 98), and the difference remained after adjustment of baseline factors (OR [95% confidence interval], 1.43 [1.10-2.02], p = 0.004).Conclusions:MR-proAM levels increase in patients with AIS, especially in those with large vessel occlusion and clinical imaging mismatch. MR-proAM is a potential biomarker for ischemic penumbra.

Stroke, Volume 53, Issue Suppl_1, Page AWP95-AWP95, February 1, 2022. Background:Acute stroke assessment and management is a time critical process. The emergency “stroke call” should include a standardised NIHSS assessment, initial observations and investigations and a decision regarding thrombolysis and thrombectomy. We found this to be daunting for trainees, and it has been documented that physician experience impacts upon door-to-needle time.Aims:The aim of our simulation training was to provide a safe environment to improve the ability and confidence of trainees in leading stroke calls with a view to improving acute stroke care and patient access to revascularization therapies.Method:We designed a one-day simulation course aimed at internal medicine trainees who are expected to lead stroke calls currently or in the immediate future. The candidates are surveyed to establish baseline confidence and complete questionnaires to assess knowledge about managing acute strokes. Here we present data from the first 18 attendees. The course is led by stroke consultants, assisted by members of the multidisciplinary team, including medical trainees, stroke specialist nurses and a paramedic. Alongside structured seminars, simulated acute stroke scenarios lead each candidate through patient handover, assessment, investigation and management decisions followed by a structured debrief. Clinical results, equipment and live monitoring are used to increase the fidelity of the simulation.Results:The course improved candidates’ confidence in leading a thrombolysis call from a mean of 2.83/10 to 7.11/10, found to be statistically significant on Paired T-Test(t=9.69, p=

Stroke, Volume 53, Issue Suppl_1, Page ATP146-ATP146, February 1, 2022. Introduction:Ample evidence exists in support of the anti-inflammatory properties of statins which in turn could affect arterial thrombosis. Compositional analysis of thrombi retrieved by MT may provide us with knowledge useful for evaluating the effect of current Statin therapy on thrombus composition.Methods:Consecutive AIS-LVO patients were included. Histopathological evaluation of thrombi retrieved during MT was performed using Martius Scarlet Blue staining (MSB) and immunohistochemistry for von Willebrand Factor (vWF) and anti-citrulinated H3 (CitH3; NETs marker) and the composition of thrombi was determined using image analysis software. Thrombus was considered rich in a given composition if that composition was higher than its overall mean. We reviewed patient’s medication records and cataloged any statin therapy prior to MT.Results:117 patients were included in this study. The mean density of red blood cells (RBCs), white blood cells (WBCs), platelets (PLT), fibrin (FIB), vWF and NETs (CitH3) in thrombi was 43.4%, 3.7%, 23.6%, 29.3%, 14.3% and 21.1% respectively. Twenty-seven patients were taking Statins at the time of MT. Statins were not associated with pre-thrombectomy IV-tPA, and stroke etiology (p values: >0.05). There was no association between Statins and thrombi composition and type (p values: >0.05 for all thrombus components and type). Additionally, Statins were not associated with MT outcomes including number of device passes and final mTICI score.Conclusion:Pre-stroke Statin therapy was not associated with differences in thrombus composition.

Stroke, Volume 53, Issue Suppl_1, Page ATP121-ATP121, February 1, 2022. Introduction:Acute ischemic stroke (AIS) patients require post-acute care (PAC) rehabilitation that is consistent with degree of stroke deficit. Appropriate PAC disposition for AIS patients varies widely. We examine the relationship between initial National Institutes of Health Stroke Scale (NIHSS) and discharge disposition to determine if stroke severity is associated with disposition.Methods:In our IRB-approved database, consecutive Emergency Department stroke code activations with confirmed diagnosis of AIS were retrospectively analyzed from January 2004-May 2021 at UC San Diego. Patients were grouped into mild (NIHSS 0-5), moderate (NIHSS 6-14), and severe (NIHSS >14) stroke. Outcome variables were PAC disposition: Home, Inpatient Rehab Facility (IRF), Skilled Nursing Facility (SNF), Expired, and Other. Chi-squared and Kruskal-Wallis followed by pairwise proportion tests were used for analysis. Analyses were adjusted for age, sex, baseline modified Rankin score (mRS), and acute stroke treatment.Results:Total 2316 patients were included for analysis. There was a difference between initial stroke severity and discharge disposition overall (p

Stroke, Volume 53, Issue Suppl_1, Page A8-A8, February 1, 2022. Purpose:Perfusion imaging assesses target mismatch but requires contrast and processing software. Clinical/diffusion mismatch can miss cases that have target mismatch and could benefit from thrombectomy. We explored whether a neural network can predict hypoperfusion and identify target mismatch from diffusion-weighted imaging (DWI) and clinical information alone.Methods:Acute ischemic stroke cases with baseline MR perfusion and DWI were included from two multi-center trials and one registry for model development and a separate randomized trial for external validation. MR perfusion images were processed by RAPID, which segments Tmax lesion (Tmax≥6s) and the ischemic core lesion (apparent diffusion coefficient [ADC]≤ 620). A 3D U-Net was trained using baseline DWI, ADC, NIH stroke scale, and side of stroke as input, and the union of Tmax and ischemic core segmentation as the ground truth. 5-fold cross-validation was performed for model development cohort. Model performance was evaluated by Dice score coefficient (DSC) and volume difference. Sensitivity and specificity of model target mismatch and clinical/diffusion mismatch criteria from the DAWN were compared, using the DEFUSE 3 target mismatch as reference.Results:413 patients were included for model development and 46 for external validation. In model development and external validation cohort, the model achieved median DSC of 0.61 (IQR 0.45, 0.71) and 0.62 (IQR 0.53, 0.72); and volume difference of 3 ml (IQR -37, 41) and 7 ml (IQR -24, 32), respectively. Compared to the clinical/diffusion mismatch approach, the model identified target mismatch with a sensitivity of 89.5% vs 49.3%, a specificity of 77.5% vs 89.2% in the model development cohort, and a sensitivity of 95.6% vs 41.3% in external validation cohort.Conclusion:A 3D U-Net can predict hypoperfusion lesions from baseline DWI and clinical information, with more sensitive classification of target mismatch than clinical/diffusion mismatch.

Stroke, Volume 53, Issue Suppl_1, Page ATP87-ATP87, February 1, 2022. Introduction:It is critical to treat Acute Ischemic Stroke (AIS) patients quickly; however, treatment eligibility is dependent on the arrival time to the nearest stroke center by Private Vehicle (PV) or Emergency Medical Services (EMS). The duration in the prehospital stage is defined as the period from stroke onset to arrival at a non-stroke center, primary stroke center or comprehensive stroke center. This study aims to detail the prehospital stage of suspected AIS patients in order to identify opportunities for process improvements.Methods:Discrete-event simulation (DES) is a powerful decision-making tool and robust methodology for evaluating treatment processes and allows for improvements to be tested before implementing changes using real resources. A DES is developed using ARENA software to model the prehospital stage of suspected AIS patients. The process steps include two treatment pathways, PV and EMS. The pathways differ because those patients arriving via EMS allow for the activation of the code stroke protocol prior to hospital arrival. The drive times from the stroke scene to the hospital were kept constant at 40 min assuming a suburban transport. The model assumes 60% recognition of ischemic stroke using EMS stroke screening tools and large vessel occlusion screening tools and a 90% probability that the paramedics correctly screen for a potential stroke and bypass to a stroke center. The primary outcome measure is median onset-to-door time, defined as the time from onset of stroke symptoms to arrival to the hospital. The Mann-Whitney U test is used for evaluating statistical significance among the outputted median onset-to-door time for all scenarios.Results:The following process improvement scenarios were run: reducing the waiting time for EMS on average from 7 min to 5 min and reducing delays on-scene on average from 20 min to 15 min, and the median onset-to-door time reductions were from a median of 57.53 min to a median of 51.41 min (p

Stroke, Volume 53, Issue Suppl_1, Page AWP25-AWP25, February 1, 2022. Objectives:Acute ischemic stroke patients with severe acute respiratory syndrome coronavirus maybe candidates for acute revascularization treatments (intravenous thrombolysis and/or mechanical thrombectomy).Materials and Methods:We analyzed the data from 62 healthcare facilities to determine the odds of receiving acute revascularization treatments in severe acute respiratory syndrome coronavirus infected patients and odds of composite of death and non-routine discharge with severe acute respiratory syndrome coronavirus infected and non-infected patients undergoing acute revascularization treatments after adjusting for potential confounders.Results:Acute ischemic stroke patients with severe acute respiratory syndrome coronavirus infection were significantly less likely to receive acute revascularization treatments (odds ratio 0.6, 95% confidence interval 0.5-0.8, p=0.0001). Among ischemic stroke patients who received acute revascularization treatments, severe acute respiratory syndrome coronavirus infection was associated with increased odds of death or non-routine discharge (odds ratio 3.0, 95% confidence interval 1.8-5.1). The higher odds death or non-routine discharge (odds ratio 2.1, 95% confidence interval 1.9-2.3) with severe acute respiratory syndrome coronavirus infection were observed in all ischemic stroke patients without any modifying effect of acute revascularization treatments (interaction term for death (p=0.9) or death or non-routine discharge (p=0.2).Conclusions:Patients with acute ischemic stroke patients with severe acute respiratory syndrome coronavirus infection were significantly less likely to receive acute revascularization treatments. Severe acute respiratory syndrome coronavirus infection was associated with a significantly higher rate of death or non-routine discharge among acute ischemic stroke patients receiving revascularization treatments.

Stroke, Volume 53, Issue Suppl_1, Page A5-A5, February 1, 2022. Context:Current guidelines recommend bed rest for 24 hours after receiving intravenous alteplase which may not be necessary and delay rehabilitation in a large proportion of acute ischemic stroke patients.Objective:To determine the feasibility of “early mobilization protocol” within the intensive care unit (ICU) in patients with acute ischemic stroke who received intravenous alteplase.Methods:All consecutive patients were admitted to the ICU with an acute ischemic stroke who received intravenous alteplase from October 2019-June 2021 were considered for “early mobilization protocol”. Patients≥18 years of age with minor, moderate or severe ischemic stroke (NIHSS score ≤22) were eligible and mobilization was initiated within 13-24 hours after intravenous alteplase administration. Exclusion criteria included hemodynamic instability, on mechanical ventilation, unstable neurological examination or progressive symptoms, or presence of external ventricular drain for hemorrhagic transformation within 24 hours of intravenous alteplase.Results:A total of 137 patients (56.8%) patients were eligible among 241 patients who were admitted to our institution with acute ischemic stroke after receiving intravenous alteplase. Mean age (±SD) was 63.4±16.6 and 66.2±17.0 years for the patients included and excluded in the early mobilization protocol, respectively. The mean NIHSS score (±SD) at baseline was 5.3±4.4 and 9.9±7.3 for the patients included and excluded in the early mobilization protocol, respectively. Early mobilization protocol was initiated at 18.3±3.6 hours in eligible patients compared with routine mobilization initiated at 41.6±19.8 hours in excluded patients (p

Stroke, Volume 53, Issue Suppl_1, Page AWMP6-AWMP6, February 1, 2022. Introduction:It is uncertain whether lowered head position improves penumbral perfusion in ischemic stroke. Although a transcranial Doppler trial in large vessel occlusion (LVO) patients suggested improvement, a large pragmatic clinical trial in mixed stroke patients was neutral. We tested the tolerability and effect on penumbral perfusion of 20-degree head-down (Trendelenburg) positioning in patients with acute LVO stroke using automated quantitative CT perfusion (CTP).Methods:We enrolled LVO patients aged ≥60, 0-24h after onset, with ≥30mL anterior circulation CTP lesion volume (delay time [DT] >3, MISTAR software). CTP was repeated after 5 minutes of 20-degree Trendelenburg positioning using a custom-designed foam wedge. Neurological status (National Institutes of Health Stroke Scale [NIHSS]) and blood pressure were recorded in routine (30 degree up) and Trendelenburg position. Trendelenburg positioning was maintained for 24h if perfusion lesion volume significantly decreased (≥5mL) and reperfusion treatment was suboptimal.Results:The target of 25 patients were enrolled (14 [56%] male, median age 76 (interquartile range [IQR]71-84), baseline modified Rankin scale score 0 [IQR0-0], median NIHSS 20 [IQR 13-24]). Most patients (15/25 [60%]) had an acute M1 middle cerebral artery (MCA) occlusion, 6 (24%) an occluded M2 MCA and 4 (16%) an occluded ICA. Stroke etiology was predominantly (15/25 [60%]) cardioembolic.Median (IQR) DT >3seconds lesion volume was significantly reduced by Trendelenburg compared with conventional horizontal CT positioning (114mL [94-204] vs 149mL [76-153] p=0.0027)). This was not explained by changes in blood pressure, which was unaltered (mean 148mmHg (+/- standard deviation 29) vs 143 (+/-27); p=0.129). Head position did not alter clinical severity (NIHSS 13 [IQR 9-28]) in both positions). A significant lesion volume reduction with Trendelenburg positioning was seen in 15/25 patients (60%); 7 received continued Trendelenburg positioning due to incomplete reperfusion. Head down positioning was well tolerated in the majority (4/7 [57%]), without serious adverse events.Conclusion:Head-down (Trendelenburg) positioning improves penumbral perfusion in acute LVO ischemic stroke and is well-tolerated.

Stroke, Volume 53, Issue Suppl_1, Page A134-A134, February 1, 2022. Intro & Background:Following the publication of the randomized clinical trials in 2015 and 2018 on endovascular stroke therapy (EVT), procedural utilization has increased. The effect of EVT utilization on clinical outcomes in acute ischemic stroke (AIS) at the population-level, however, remains incompletely characterized.Methods & Materials:We performed a retrospective cross-sectional analysis using the Texas Public Use Data File with records from January 2016 through the first quarter of 2020. This dataset includes full sample data on all patients hospital discharged from all state-licensed hospitals. AIS hospitalizations were identified as those with a primary diagnosis of AIS by ICD-10 diagnostic codes. Patients

Stroke, Volume 53, Issue Suppl_1, Page AWMP28-AWMP28, February 1, 2022. Background and Purpose:Acute stroke patients who receive intravenous (IV) alteplase have historically remained on bedrest for the first 24 hours after infusion completion. We sought to determine the safety and feasibility of mobilizing patients with low NIHSS between 6 and 24 hours post-alteplase infusion.Methods:Patients with NIHSS ≤5 after IV alteplase infusion were included. We excluded patients also undergoing mechanical thrombectomy. Subjects were stratified into an early mobilization group and a standard care group based on nursing compliance with an early mobilization protocol. Safety endpoints included falls, neurological deterioration in NIHSS (increase of ≥ 2 points), and physiological events (defined by out-of-range vital signs). Each safety endpoint was quantified for both groups. Additionally, demographic characteristics and past medical history were compared between the groups to identify any statistically significant differences (p < 0.05).Results:Between June 2020 and April 2021, 93 acute stroke patients received IV alteplase and had an NIHSS of ≤5 following thrombolytic therapy. Of the included subjects, 54 received early mobilization while 39 did not. There were no statistically significant differences in gender, race, or past medical history between the two groups. Among safety endpoints, there were no reported instances of falls, neurological deterioration in NIHSS, or significant physiological events in either group.Conclusions:Our study demonstrates that instituting early mobilization as soon as 6 hours after alteplase infusion completion is safe and feasible mild acute stroke patients. Future studies should explore efforts to increase the number of patients who receive early mobilization and investigate functional outcomes between patients receiving early mobilization compared to standard medical care.

Stroke, Volume 53, Issue Suppl_1, Page AWMP1-AWMP1, February 1, 2022. Approved thrombolytic agents are limited in their use for the treatment of acute ischemic stroke (AIS) due to their benefit-risk profile beyond 4.5 h since last known normal (LKN). TMS-007 is a small molecule, SMTP family member with a novel mode of action: promotion of plasminogen-fibrin binding to enhance physiological thrombolysis while inhibiting inflammation at the site of thrombosis. TMS-007 may extend the treatment time window based on nonclinical pharmacological evidence. We evaluated TMS-007 in a randomized, placebo-controlled, double-blind, dose-escalation phase 2a study. TMS-007 or placebo was administered as a single intravenous infusion at a dose of 1, 3, or 6 mg/kg to AIS patients who were ineligible for t-PA or thrombectomy within 12 h of LKN. The number of patients allocated to placebo and TMS-007 at doses 1, 3, and 6 mg/kg were 38, 6, 18, and 28, respectively. The combined TMS-007 dosing group (Group T; n = 52) was compared with placebo group (Group P; n = 38). The average age was ~72 years old and time since LKN to treatment was ~9 h in both groups (not significantly different). The incidence of symptomatic intracranial hemorrhage (ICH) with worsening NIHSS score of

Stroke, Volume 53, Issue Suppl_1, Page AWMP29-AWMP29, February 1, 2022. Background:Stroke is the leading cause of disability and the 5th leading cause of death in the US. The advent of tissue plasminogen activator (TPA) was a game changer in the treatment of acute ischemic stroke. Today at Cedars Sinai Medical Center, we have implemented the use of Tenecteplase (TNK) for our Code Brain patients, a more cost-effective, easier- to- use thrombolytic. TNK is non- inferior to TPA and studies show a potential benefit in reperfusion of large vessel occlusions (NEJM, 2018).Hypothesis:To decrease the ED and inpatient door-to-needle (DTN) times, and thrombolytic with thrombectomy (bridge) door-to-groin (DTG) puncture times, by June 20, 2021 using TNK, as measured by data acquired 6 months prior to TNK implementation (July 20, 2020 through January 19, 2021) and data acquired 6 months after TNK implementation (January 20, 2021 through June 20, 2021).Implementation:We performed a retrospective chart review of times for patients who received TNK alone and: for those who received bridge therapy after TNK implementation. These times were compared with 6 months of data prior to TNK implementation.Results:Our review of the data revealed that the median times for ED DTN, in-house DTN and bridge DTP were 46, 61.5, and 98.5 minutes respectively. Data for six months after the implementation of TNK reveals that the median times for ED DTN, in-house DTN and bridge DTP were 48, 51.5, and 88 minutes respectively.Conclusions:We discovered that although ED DTN times were unremarkable, our in-house DTN times and bridge DTP times markedly improved. In fact, for the first time, we have surpassed the American Heart Association benchmark of 90 minutes DTP times. We conclude that TNK is easier to administer, more cost effective, and decreased our treatment times for our in-house Code Brain patients who received TNK alone and our Code brain patients who received bridge therapy. We will continue to track and trend this data and seek out areas of improvement.

Stroke, Volume 53, Issue Suppl_1, Page AWP97-AWP97, February 1, 2022. Background and Purpose:Rapid detection of large vessel occlusion (LVO) is essential for rapid triage for thrombectomy to salvage at-risk tissue. Early detection of LVO on noncontrast CT head (NCCT) could facilitate triage before advanced imaging is obtained. RAPID hyperdense vessel sign (HVS), a new fully automated software- tool for HVS detection is compared to experienced radiologists, for early LVO detection on NCCT, and validated with CTA.Methods:Scans were selected from a database of 335 scans, of which 166 were selected by stratified random selection. Images were evaluated by the Rapid automated software, and six readers, two radiologists, and four neuroradiologists. The Rapid algorithm returns a score between zero and one, and a threshold of 0.5 was applied of HVS. Radiologists read each scan twice, 30 days apart. A scan rating confidence scale was used, from “very confident of absence,” to “very confident of HVS,” and a separate “technically inadequate” rating, and this was compared to the Rapid HVS score. “Very Confident,” or “Confident” rated scans were considered HVS positive.Results:Demographics: 54% were men. Ages ranged 23 – 94 with a median of 65. GE, Philips, Siemens, and Toshiba scanners are represented. Agreement with RAPID for HVS detection was 75% to 84%. Below a HVS score of 0.4 the proportion of LVO positive scans was 46% (indeterminate), between 0.4 and 0.6 the proportion was 62.5% (probable), and above 0.6 the proportion was 90% (likely). The scan rating confidence grade correlated with the Rapid HVS score. The software identified 53% of the LVOs, comparable to human readers (26-57%) A clinical practice simulation of RAPID followed by a reader identified 61.3% (p=0.02 vs readers alone). Among the 61 patients with no LVO on CTA, readers had a false positive rate of less than 7% as compared to 15% for the software. Median software processing time was 54 seconds.Conclusions:Expert readers, and the Rapid software, detect an HVS in about 50% of CT head images with LVO on CTA. When Rapid software is used in tandem with an experienced reader, HVS can be detected in up to two thirds of patients with LVO on CTA. This high percentage of early LVO detection would facilitate faster triage of patients for more advanced imaging and/or therapeutic interventions.