Predictive Value of Modifications of the Prehospital Rapid Arterial Occlusion Evaluation Scale for Large Vessel Occlusion in Patients with Acute Stroke

Introduction25%-30% of patients admitted with acute stroke are stroke mimics. Clinical assessment plays a major role in diagnosis in the hyperacute clinical setting. Identifying physical signs that correctly identify stroke is therefore important. A retrospective study1 suggested that the presence of sensory inattention (or neglect) was seen exclusively in stroke patients, suggesting that inattention might be a reliable discriminator between stroke and mimics. This study aimed to test that hypothesis.MethodsProspective assessment of suspected stroke patients for the presence of neglect (NIHSS definition). Neglect could be visual and/or somatosensory. The presence of neglect was then correlated with eventual diagnosis at 48 hours. Sensitivity, specificity and predictive values were calculated. A post-hoc analysis evaluated the correlation of neglect with large vessel occlusion in patients who underwent angiography.Results115 patients were recruited, 70 ultimately with stroke and 45 with other diagnoses. Neglect was present in 27 patients (of whom 23 had stroke) and absent in 88. This yielded: sensitivity 32.9%, specificity 91.1%, positive predictive value 85.2%, and negative predictive value 41.9%. Two patients with neglect had a diagnosis of functional illness, one a seizure, and one a brain tumour. Neglect was present in 7 out of 8 patients with large vessel occlusion (sensitivity 87.5%) and was absent in all patients who did not have large vessel occlusion on angiogram.ConclusionWhen present, neglect is a strong predictor of organic pathology and large vessel occlusion. However, it is not 100% specific and can be seen in functional presentations.ReferenceGargalas S, Weeks R, Khan-Bourne N, Shotbolt P, Simblett S, Ashraf L, Doyle C, Bancroft V, David AS: Incidence and outcome of functional stroke mimics admitted to a hyperacute stroke unit. J Neurol Neurosurg Psychiatry 2017, 88:2–6.

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Transfer to the Local Stroke Center versus Direct Transfer to Endovascular Center of Acute Stroke Patients with Suspected Large Vessel Occlusion in the Catalan Territory (RACECAT): Study protocol of a cluster randomized within a cohort trial

International Journal of Stroke ◽

10.1177/1747493019852176 ◽

2019 ◽

Vol 14 (7) ◽

pp. 734-744 ◽

Cited By ~ 10

Author(s):

Sònia Abilleira ◽

Natalia Pérez de la Ossa ◽

Xavier Jiménez ◽

Pere Cardona ◽

Dolores Cocho ◽

...

Keyword(s):

Endovascular Treatment ◽

Acute Stroke ◽

Arterial Occlusion ◽

Large Vessel ◽

Modified Rankin Scale ◽

Large Vessel Occlusion ◽

Stroke Patients ◽

Vessel Occlusion ◽

Stroke Center ◽

Cluster Randomized

Rationale Optimal pre-hospital delivery pathways for acute stroke patients suspected to harbor a large vessel occlusion have not been assessed in randomized trials. Aim To establish whether stroke subjects with rapid arterial occlusion evaluation scale based suspicion of large vessel occlusion evaluated by emergency medical services in the field have higher rates of favorable outcome when transferred directly to an endovascular center (endovascular treatment stroke center), as compared to the standard transfer to the closest local stroke center (local-SC). Design Multicenter, superiority, cluster randomized within a cohort trial with blinded endpoint assessment. Procedure Eligible patients must be 18 or older, have acute stroke symptoms and not have an immediate life threatening condition requiring emergent medical intervention. They must be suspected to have intracranial large vessel occlusion based on a pre-hospital rapid arterial occlusion evaluation scale of ≥5, be located in geographical areas where the default health authority assigned referral stroke center is a non-thrombectomy capable hospital, and estimated arrival at a thrombectomy capable stroke hospital in less than 7 h from time last seen well. Cluster randomization is performed according to a pre-established temporal sequence (temporal cluster design) with three strata: day/night, distance to the endovascular treatment stroke center, and week/week-end day. Study outcome The primary endpoint is the modified Rankin Scale score at 90 days. The primary safety outcome is mortality at 90 days. Analysis The primary endpoint based on the modified intention-to-treat population is the distribution of modified Rankin Scale scores at 90 days analyzed under a sequential triangular design. The maximum sample size is 1754 patients, with two planned interim analyses when 701 (40%) and 1227 patients have completed follow-up. Hypothesized common odds ratio is 1.35.

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Retrospective Validation of Prehospital Acute Stroke Severity Scale to Predict Large Vessel Occlusion in Acute Stroke Patients - Single Center study in China

10.21203/rs.2.10860/v1 ◽

2019 ◽

Author(s):

Xiaoli Si ◽

Yuanjian Fang ◽

Wenqing Xia ◽

Tianwen Chen ◽

Huan Huang ◽

...

Keyword(s):

Acute Stroke ◽

Predictive Value ◽

Large Vessel ◽

Motor Deficits ◽

Stroke Severity ◽

Large Vessel Occlusion ◽

Anterior Circulation ◽

Vessel Occlusion ◽

Consciousness Disorder ◽

Gaze Palsy

Abstract Background and Purpose - To date, identifying emergent large vessel occlusion (ELVO) patients in the prehospital stage is important but still challenging. We aimed to retrospectively validate a simple prehospital stroke scale——Prehospital Acute Stroke Severity (PASS) scale to identify ELVO. Methods - We retrospectively evaluated our consecutive cohort of acute ischemic stroke (AIS) who underwent CT angiography (CTA), MR angiography (MRA) or digital subtraction angiography (DSA). PASS scale was calculated based on National Institutes of Health Stroke Scale (NIHSS) items retrospectively. The comparison of diagnostic parameters between PASS scale and NIHSS scale were performed. Results - Finally, a total of 605 patients were enrolled. ELVO patients with PASS≥2 had a median NIHSS score of 14. The best predictive value of PASS≥2 showed a similar predictive value compared with NIHSS≥9. Cortical symptoms such as consciousness disorder and gaze palsy were more specific indicators for ELVO than motor deficits. Consciousness disorder was more serious in posterior circulation infarct (PIC) while gaze palsy was more common in anterior circulation infarct (AIC). Conclusions - PASS scale had both good discrimination and calibration in our retrospective cohort. It could reflect acute stroke severity well and predict ELVO in an effective and simple way. Moreover, cortical symptoms had high specificities to predict ELVO on their own.

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Abstract TMP62: Utility of the Los Angeles Motor Scale to Identify Emergency Large Vessel Occlusion in Acute Stroke

Stroke ◽

10.1161/str.48.suppl_1.tmp62 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Prasannna Tadi ◽

Pranav Reddy ◽

Sravanthi Pemmasani ◽

Nasir Fakhri ◽

Matthew Siket ◽

...

Keyword(s):

Los Angeles ◽

Positive Predictive Value ◽

Acute Stroke ◽

Negative Predictive Value ◽

Predictive Value ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Vessel Imaging ◽

Los Angeles Motor Scale

Introduction: Stroke is a common medical emergency. The outcome depends upon access to stroke specialists, rapid scanning, assessment, and treatments. Identification of large vessel occlusion (LVO) is critical in the selection of patients for emergency embolectomy (clot removal) in patients with acute ischemic stroke. A pre-hospital stroke severity scale, such as the Los Angeles Motor Scale (LAMS) may have utility in selecting appropriate patients for CTA, while minimizing radiation exposure risk to the population as a whole. Methods: This was a retrospective analysis of 249 consecutive code stroke activations at a comprehensive stroke center during a 3.5 month period using a LAMS cutoff of ≥4 to trigger CTA acquisition. We determined the sensitivity, specificity, positive predictive value, and negative predictive value of using LAMS to detect large vessel occlusion (LVO). Gold standard was any vessel imaging within 24 hours. Inter-rater reliability of LAMS scoring was determined by blinded scoring of physical exam data from the chart by 3 neurovascular physicians. Results: There were 249 code stroke activations during the study period: 91 acute CTAs were recommended based on LAMS scoring. 20 large vessel occlusions were detected. 158 patients did not have a CTA acutely; none had a LVO during subsequent vessel imaging. The sensitivity is 100%, negative predictive value 100%, specificity 69%, positive predictive value 22% of the LAMS triage method. Inter-rater Reliability: Shrout-Fleiss pairwise weighted kappa coefficients between the three raters on LAMS scores were 0.67, 0.55, and 0.62. Kappa coefficients for pairs of raters when LAMS were dichotomized as <3 vs 4-5 were 0.64, 0.50, and 0.71. Clinically meaningful disagreements were evident. Conclusions: Accuracy and ease-of-use makes LAMS an ideal clinical tool to rapidly assess acute stroke patients for LVO and emergency mechanical thrombectomy. LAMS demonstrated excellent sensitivity in excluding patients who did not have a LVO. Appropriate training is required to ensure accuracy of LAMS scoring by providers.

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Abstract TP240: The PLUMBER (Prevalence of Large Vessel Occlusion Stroke in Mecklenburg County Emergency Response) Study

Stroke ◽

10.1161/str.48.suppl_1.tp240 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Adeline R Dozois ◽

Lorrie Hampton ◽

Carlene W Kingston ◽

Gwen Lambert ◽

Thomas J Porcelli ◽

...

Keyword(s):

Acute Stroke ◽

Emergency Response ◽

Predictive Value ◽

Large Vessel ◽

Stroke Severity ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Mecklenburg County ◽

Ischemic Attack ◽

Neurovascular Imaging

Introduction: Regional Emergency Medical System (EMS) protocols for acute stroke endorse routing patients with possible large vessel occlusion (LVO) acute ischemic strokes (AIS) directly to endovascular centers. These routing algorithms include prehospital stroke severity screens (PSSS) to determine the likelihood of an LVO AIS. An essential, but unreported, determinant of the predictive value of PSSS tools is the prevalence of LVO AIS stroke in the EMS population screened for stroke. Hypothesis: Among EMS patients transported to Mecklenburg county hospitals screened for stroke, acute LVO AIS prevalence ranges from 5-10%. Methods: We are conducting a prospective, observational study of all patients transported by the Mecklenburg county EMS agency who are either (1) dispatched as a possible stroke and/or (2) with a primary impression of stroke recorded by prehospital providers. We are reviewing medical records and neurovascular imaging studies to determine an acute LVO AIS diagnosis and the site(s) of occlusion. Results: Thus far, over a six-month period we have enrolled 1441 patients, of whom 33% (n=480) had a diagnosis consistent with acute stroke (ischemic stroke, hemorrhagic stroke, or transient ischemic attack), with 20% (n=287) being an AIS. Eighty-eight percent (n=253) of AIS patients underwent an intracranial CTA or MRA. The prevalence of LVO stroke in the EMS population enrolled was 5.7% (n= 82, 95% CI 4.6-7.0%), with the most common vessel occluded being M1 (n=46, 56% of LVO AIS). The prevalence of LVO AIS in patients dispatched as a possible stroke was 4.8% (n =56; 95% CI 3.6-6.1%), while the prevalence in patients with a primary impression of stroke was 10% (n=74; 95% CI 8.2-13%). Conclusions: Among patients screened for stroke by our county’s EMS agency, the prevalence of LVO AIS is low. This low LVO AIS prevalence, combined with a PSSS tool with modest accuracy, will yield poor predictive value for LVO AIS in an EMS population, resulting in a substantial rate of over-triage of non-LVO patients to endovascular centers. Data collection is ongoing to determine the accuracy of a prehospital stroke screen in identifying LVO AIS patients.

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Diagnostic value of transcranial ultrasonography for selecting subjects with large vessel occlusion: a systematic review

The Ultrasound Journal ◽

10.1186/s13089-019-0143-6 ◽

2019 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Daria Antipova ◽

Leila Eadie ◽

Ashish Stephen Macaden ◽

Philip Wilson

Keyword(s):

Systematic Review ◽

Diagnostic Accuracy ◽

Acute Stroke ◽

Clinical Assessment ◽

Assessment Tools ◽

Large Vessel ◽

Cochrane Library ◽

Direct Transfer ◽

Large Vessel Occlusion ◽

Vessel Occlusion

Abstract Introduction A number of pre-hospital clinical assessment tools have been developed to triage subjects with acute stroke due to large vessel occlusion (LVO) to a specialised endovascular centre, but their false negative rates remain high leading to inappropriate and costly emergency transfers. Transcranial ultrasonography may represent a valuable pre-hospital tool for selecting patients with LVO who could benefit from rapid transfer to a dedicated centre. Methods Diagnostic accuracy of transcranial ultrasonography in acute stroke was subjected to systematic review. Medline, Embase, PubMed, Scopus, and The Cochrane Library were searched. Published articles reporting diagnostic accuracy of transcranial ultrasonography in comparison to a reference imaging method were selected. Studies reporting estimates of diagnostic accuracy were included in the meta-analysis. Results Twenty-seven published articles were selected for the systematic review. Transcranial Doppler findings, such as absent or diminished blood flow signal in a major cerebral artery and asymmetry index ≥ 21% were shown to be suggestive of LVO. It demonstrated sensitivity ranging from 68 to 100% and specificity of 78–99% for detecting acute steno-occlusive lesions. Area under the receiver operating characteristics curve was 0.91. Transcranial ultrasonography can also detect haemorrhagic foci, however, its application is largely restricted by lesion location. Conclusions Transcranial ultrasonography might potentially be used for the selection of subjects with acute LVO, to help streamline patient care and allow direct transfer to specialised endovascular centres. It can also assist in detecting haemorrhagic lesions in some cases, however, its applicability here is largely restricted. Additional research should optimize the scanning technique. Further work is required to demonstrate whether this diagnostic approach, possibly combined with clinical assessment, could be used at the pre-hospital stage to justify direct transfer to a regional thrombectomy centre in suitable cases.

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Abstract 1122‐000022: Delays in Care for Patients with Acute Stroke During Hospitalization for Other Reasons

Stroke: Vascular and Interventional Neurology ◽

10.1161/svin.01.suppl_1.000022 ◽

2021 ◽

Vol 1 (S1) ◽

Author(s):

Nicholas Vigilante ◽

Parth Patel ◽

Prasanth Romiyo ◽

Lauren Thau ◽

Mark Heslin ◽

...

Keyword(s):

Acute Stroke ◽

Acute Care ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Single Center ◽

Anterior Circulation ◽

Vessel Occlusion ◽

Symptom Recognition ◽

Risk Patients ◽

Recognition Imaging

Introduction : In‐hospital stroke (IHS) is defined as stroke that occurs during hospitalization for non‐stroke conditions. We aimed to understand the timing of symptom recognition for patients who experienced IHS and its impact on the care they receive. Methods : A prospective, single center registry of adult patients (9/20/19‐2/28/21) was queried for acute anterior circulation IHS. Indications for hospitalization, delays from last known well (LKW) to symptom recognition, imaging, and treatment were explored. Results : Of 928 consecutively evaluated adults with acute stroke, 85 (9%) developed an anterior circulation IHS, 39 (46%) of whom were female, with a median age of 67 years (IQR 60–76) and median NIHSS of 15 (IQR 4–22). Sixty‐eight (80%) had a >1 hour delay from last known well to symptom recognition. Two patients (2%) received IV thrombolysis, although another 38 (45%) would have been eligible if not for a delay in symptom recognition. An ICA, M1, or M2 occlusion was observed in 18 patients (21%), 7 of whom were treated at a median of 174 minutes after LKW (IQR 65–219). Compared to the 11 patients who did not undergo thrombectomy with large vessel occlusion, those who underwent thrombectomy had non‐significantly shorter delays from LKW until neuroimaging (median 85 [IQR 65‐162] vs. 216 [IQR 133‐507], p = 0.12). Conclusions : While uncommon, patients with IHS experience delays in symptom recognition and treatment, which lead to exclusion from acute care treatment such as thrombolysis and thrombectomy. Earlier detection with more frequent nursing assessments or advanced neuromonitoring devices in at‐risk patients may reduce delays in care.

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Epidemiological Surveillance of the Impact of the COVID-19 Pandemic on Stroke Care Using Artificial Intelligence

Stroke ◽

10.1161/strokeaha.120.031960 ◽

2021 ◽

Author(s):

Raul G. Nogueira ◽

Jason M. Davies ◽

Rishi Gupta ◽

Ameer E. Hassan ◽

Thomas Devlin ◽

...

Keyword(s):

Artificial Intelligence ◽

Acute Stroke ◽

Systems Of Care ◽

Ct Perfusion ◽

Stroke Care ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Number Of Patients ◽

The Impact

Background and Purpose: The degree to which the coronavirus disease 2019 (COVID-19) pandemic has affected systems of care, in particular, those for time-sensitive conditions such as stroke, remains poorly quantified. We sought to evaluate the impact of COVID-19 in the overall screening for acute stroke utilizing a commercial clinical artificial intelligence platform. Methods: Data were derived from the Viz Platform, an artificial intelligence application designed to optimize the workflow of patients with acute stroke. Neuroimaging data on suspected patients with stroke across 97 hospitals in 20 US states were collected in real time and retrospectively analyzed with the number of patients undergoing imaging screening serving as a surrogate for the amount of stroke care. The main outcome measures were the number of computed tomography (CT) angiography, CT perfusion, large vessel occlusions (defined according to the automated software detection), and severe strokes on CT perfusion (defined as those with hypoperfusion volumes >70 mL) normalized as number of patients per day per hospital. Data from the prepandemic (November 4, 2019 to February 29, 2020) and pandemic (March 1 to May 10, 2020) periods were compared at national and state levels. Correlations were made between the inter-period changes in imaging screening, stroke hospitalizations, and thrombectomy procedures using state-specific sampling. Results: A total of 23 223 patients were included. The incidence of large vessel occlusion on CT angiography and severe strokes on CT perfusion were 11.2% (n=2602) and 14.7% (n=1229/8328), respectively. There were significant declines in the overall number of CT angiographies (−22.8%; 1.39–1.07 patients/day per hospital, P <0.001) and CT perfusion (−26.1%; 0.50–0.37 patients/day per hospital, P <0.001) as well as in the incidence of large vessel occlusion (−17.1%; 0.15–0.13 patients/day per hospital, P <0.001) and severe strokes on CT perfusion (−16.7%; 0.12–0.10 patients/day per hospital, P <0.005). The sampled cohort showed similar declines in the rates of large vessel occlusions versus thrombectomy (18.8% versus 19.5%, P =0.9) and comprehensive stroke center hospitalizations (18.8% versus 11.0%, P =0.4). Conclusions: A significant decline in stroke imaging screening has occurred during the COVID-19 pandemic. This analysis underscores the broader application of artificial intelligence neuroimaging platforms for the real-time monitoring of stroke systems of care.

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Pomona Large Vessel Occlusion Screening Tool for Prehospital and Emergency Room Settings

Interventional Neurology ◽

10.1159/000486515 ◽

2018 ◽

Vol 7 (3-4) ◽

pp. 196-203 ◽

Cited By ~ 2

Author(s):

Kessarin Panichpisal ◽

Kenneth Nugent ◽

Maharaj Singh ◽

Richard Rovin ◽

Reji Babygirija ◽

...

Keyword(s):

Los Angeles ◽

Acute Stroke ◽

Predictive Value ◽

Area Under The Curve ◽

Predictive Performance ◽

Large Vessel ◽

Stroke Severity ◽

Vessel Occlusion ◽

Comparable Accuracy ◽

Score Model

Background: Early identification of patients with acute ischemic strokes due to large vessel occlusions (LVO) is critical. We propose a simple risk score model to predict LVO. Method: The proposed scale (Pomona Scale) ranges from 0 to 3 and includes 3 items: gaze deviation, expressive aphasia, and neglect. We reviewed a cohort of all acute stroke activation patients between February 2014 and January 2016. The predictive performance of the Pomona Scale was determined and compared with several National Institutes of Health Stroke Scale (NIHSS) cutoffs (≥4, ≥6, ≥8, and ≥10), the Los Angeles Motor Scale (LAMS), the Cincinnati Prehospital Stroke Severity (CPSS) scale, the Vision Aphasia and Neglect Scale (VAN), and the Prehospital Acute Stroke Severity Scale (PASS). Results: LVO was detected in 94 of 776 acute stroke activations (12%). A Pomona Scale ≥2 had comparable accuracy to predict LVO as the VAN and CPSS scales and higher accuracy than Pomona Scale ≥1, LAMS, PASS, and NIHSS. A Pomona Scale ≥2 had an accuracy (area under the curve) of 0.79, a sensitivity of 0.86, a specificity of 0.70, a positive predictive value of 0.71, and a negative predictive value of 0.97 for the detection of LVO. We also found that the presence of either neglect or gaze deviation alone had comparable accuracy of 0.79 as Pomona Scale ≥2 to detect LVO. Conclusion: The Pomona Scale is a simple and accurate scale to predict LVO. In addition, the presence of either gaze deviation or neglect also suggests the possibility of LVO.

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Abstract TMP35: Clinical Stroke Scales in Predicting Large Vessel Occlusion: A Metaanalysis

Stroke ◽

10.1161/str.48.suppl_1.tmp35 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

W Y kong ◽

Andrew Choong ◽

Nicholas Syn ◽

Vijay K Sharma ◽

Hock L Teoh ◽

...

Keyword(s):

Reference Lists ◽

Data Extraction ◽

Meta Analysis ◽

Arterial Occlusion ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Computed Tomography Angiogram ◽

Sensitivity Specificity ◽

Stroke Centre

Background: Identifying large vessel occlusion (LVO) is paramount in the era of endovascular therapy. This can be achieved easily by computed tomography angiogram(CTA) and magnetic resonance angiography(MRA). National Institute Health Stroke Scale(NIHSS) threshold can be used in primary stroke centre(PSC) without these facilities, to identify patients with LVO for transfer to a comprehensive stroke centre (CSC) for mechanical thrombectomy. Alternatively, simplified clinical stroke scales (CSS)can also be used by emergency medical services (EMS) to identify such patients to be directly transported to CSC. We aim to compare various CSS in predicting LVO in ischemic stroke. Methods: We searched PUBMED from January 2005 to July 2016 and screened reference lists of included studies, and included all diagnostic accuracy studies that investigate CSS and prediction of LVO confirmed with CTA or MRA. Two authors independently screened titles and abstracts and perform data extraction for analysis. Pooled sensitivity, specificity and diagnostic odd ratio (DOR) of various CSS were obtained using the random effects model. Result: 8 studies (total 8556 patients) were included for meta-analysis of 3 CSS. This includes the NIHSS≥5, ≥6, ≥10, ≥13; Cincinnati Prehospital Stroke Scale (CPSS)≥2 and Rapid Arterial oCclusion Evaluation (RACE) ≥ 5. Pooled sensivity and specificty for the respective cut off values of these CSS was metaanalysed and presented in table 1. NIHSS≥13 has the highest DOR (26.0), followed by NIHSS≥5 (16.9); whereas other NIHSS thresholds, CPSS and RACE were less predictive. NIHSS≥5 was found to have the highest sensitivity of 0.865 and NIHSS≥13 had the highest specificity of 0.934. Conclusion: We found 2 NIHSS thresholds that were most useful for identifying LVO. Depending on resources and preferences of each stroke centre, different NIHSS threshold can be utilized for purpose of ruling in LVO using a high NIHSS threshold, or ruling out LVO using a low NIHSS threshold.

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