SuperDyna: Unlocking the Potential of Post-Treatment Device Evaluation

BACKGROUND

Current imaging algorithms for post-device evaluation are limited by either poor representation of the device or poor delineation of the treated vessel. Combining the high-resolution images from a traditional three-dimensional digital subtraction angiography (3D-DSA) protocol with the longer cone-beam computed tomography (CBCT) protocol may provide simultaneous visualization of both the device and the vessel content in a single volume, improving the accuracy and detail of the assessment. We aim here to review our use of this technique which we termed "SuperDyna".

METHODS

In this retrospective study, patients who underwent an endovascular procedure between February 2022 and January 2023 were identified. We analyzed patients who had both non-contrast CBCT and 3D-DSA post-treatment and collected information on pre-/post-blood urea nitrogen, creatinine, radiation dose, and the intervention type.

RESULTS

In 1 year, SuperDyna was performed in 52 (of 1935, 2.6%) patients, of which 72% were women, median age 60 years. The most common reason for the addition of the SuperDyna was for post-flow diversion assessment (n=39). Renal function tests showed no changes. The average total procedure radiation dose was 2.8 Gy, with 4% dose and ~20 mL of contrast attributed to the additional 3D-DSA needed to generate the SuperDyna.

CONCLUSIONS

The SuperDyna is a fusion imaging method that combines high-resolution CBCT and contrasted 3D-DSA to evaluate intracranial vasculature post-treatment. It allows for more comprehensive evaluation of the device position and apposition, aiding in treatment planning and patient education.

Superficial Temporal Artery to Middle Cerebral Artery Cranial Bypass for Nonmoyamoya Steno-Occlusive Disease in Patients Who Failed Optimal Medical Treatment: A Case Series

BACKGROUND

In the post-Carotid Occlusion Surgery Study (COSS) era, multiple reviews suggested subset groups of patients as potential candidates for superficial temporal artery to middle cerebral artery (STA-MCA) bypass. Among them are patients with recurrent strokes despite optimal medical therapy. There is a paucity of data on the outcome of bypass in these specific patients.

OBJECTIVE

To examine the safety and efficacy of direct STA-MCA bypass in patients with nonmoyamoya, symptomatic steno-occlusive disease with impaired distal perfusion, who failed optimal medical management or endovascular treatment.

METHODS

A retrospective review was performed to identify patients with cerebrovascular steno-occlusive disease who underwent bypass after symptomatic recurrent or rapidly progressive strokes, despite optimal conservative or endovascular treatment.

RESULTS

A total of 8 patients (mean age 60 ± 6 yr) underwent direct or combined direct/indirect STA-MCA bypass between 2016 and 2019. All anastomoses were patent. One bypass carried slow flow. There were no procedure-related permanent deficits. One patient developed seizures which were controlled by medications. A total of 7 out of 8 patients were stable or improved clinically at last follow-up (mean 27.3 ± 13.8 mo) without recurrent strokes. One patient did not recover from their presenting stroke, experienced severe bilateral strokes 4 mo postoperatively, and subsequently expired. Modified Rankin Scale (mRS) improved in 6 patients (75%), remained stable in 1 patient (12.5%), and deteriorated in 1 (12.5%). Good long-term functional outcome was achieved in 5 patients (63%, mRS ≤ 2).

CONCLUSION

Patients with symptomatic, hypoperfused steno-occlusive disease who fail optimal medical or endovascular treatment may benefit from cerebral revascularization. Direct or combined STA-MCA bypass was safe and provided favorable outcomes in this small series.

Carotid Stenosis and Recurrent Ischemic Stroke: A Post-Hoc Analysis of the POINT Trial

BACKGROUND AND PURPOSE

Randomized trials demonstrated the benefit of dual antiplatelet therapy in patients with minor ischemic stroke or high-risk transient ischemic attack. We sought to determine whether the presence of carotid stenosis was associated with increased risk of ischemic stroke and whether the addition of clopidogrel to aspirin was associated with more benefit in patients with versus without carotid stenosis.

METHODS

This is a post-hoc analysis of the POINT trial (Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke) that randomized patients with minor ischemic stroke or high-risk transient ischemic attack within 12 hours from last known normal to receive either clopidogrel plus aspirin or aspirin alone. The primary predictor was the presence of ≥50% stenosis in either cervical internal carotid artery. The primary outcome was ischemic stroke. We built Cox regression models to determine the association between carotid stenosis and ischemic stroke and whether the effect of clopidogrel was modified by ≥50% carotid stenosis.

RESULTS

Among 4881 patients enrolled POINT, 3941 patients met the inclusion criteria. In adjusted models, ≥50% carotid stenosis was associated with ischemic stroke risk (hazard ratio, 2.45 [95% CI, 1.68-3.57], P<0.001). The effect of clopidogrel (versus placebo) on ischemic stroke risk was not significantly different in patients with <50% carotid stenosis (adjusted hazard ratio, 0.68 [95% CI, 0.50-0.93], P=0.014) versus those with ≥50% carotid stenosis (adjusted hazard ratio, 0.88 [95% CI, 0.45-1.72], P=0.703), P value for interaction=0.573.

CONCLUSIONS

The presence of carotid stenosis was associated with increased risk of ischemic stroke during follow-up. The effect of added clopidogrel was not significantly different in patients with versus without carotid stenosis. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03354429.

Endarterectomy for symptomatic internal carotid artery web

OBJECTIVE

The carotid web (CW) is an underrecognized source of cryptogenic, embolic stroke in patients younger than 55 years of age, with up to 37% of these patients found to have CW on angiography. Currently, there are little data detailing the best treatment practices to reduce the risk of recurrent stroke in these patients. The authors describe their institutional surgical experience with patients treated via carotid endarterectomy (CEA) for a symptomatic internal carotid artery web.

METHODS

A retrospective, observational cohort study was performed including all patients presenting to the authors' institution with CW. All patients who were screened underwent either carotid artery stenting (CAS) or CEA after presentation with ischemic stroke from January 2019 to February 2020. From this sample, patients with suggestive radiological features and pathologically confirmed CW who underwent CEA were identified. Patient demographics, medical histories, radiological images, surgical results, and clinical outcomes were collected and described using descriptive statistics.

RESULTS

A total of 45 patients with symptomatic carotid lesions were treated at the authors' institution during the time period. Twenty patients underwent CAS, 1 of them for a CW. Twenty-five patients were treated via CEA, and of these, 6 presented with ischemic strokes ipsilateral to CWs, including 3 patients who presented with recurrent strokes. The mean patient age was 55 ± 12.6 years and 5 of 6 were women. CT angiography or digital subtraction angiography demonstrated the presence of CWs ipsilateral to the stroke in all patients. All patients underwent resection of CWs using CEA. There were no permanent procedural complications and no patients had stroke recurrence following intervention at the latest follow-up (mean 6.1 ± 4 months). One patient developed mild tongue deviation most likely related to retraction, with complete recovery at follow-up.

CONCLUSIONS

CEA is a safe and feasible treatment for symptomatic carotid webs and should be considered a viable alternative to CAS in this patient population.

Redefined Measure of Early Neurological Improvement Shows Treatment Benefit of Alteplase Over Placebo

Background and Purpose- The first of the 2 NINDS (National Institute of Neurological Disorders and Stroke) Study trials did not show a significant increase in early neurological improvement, defined as National Institutes of Health Stroke Scale (NIHSS) improvement by ≥4, with alteplase treatment. We hypothesized that early neurological improvement defined as a percentage change in NIHSS (percent change NIHSS) at 24 hours is superior to other definitions in predicting 3-month functional outcomes and using this definition there would be treatment benefit of alteplase over placebo at 24 hours. Methods- We analyzed the NINDS rt-PA Stroke Study (Parts 1 and 2) trial data. Percent change NIHSS was defined as ([admission NIHSS score-24-hour NIHSS score]×100/admission NIHSS score] and delta NIHSS as (admission NIHSS score-24-hour NIHSS score). We compared early neurological improvement using these definitions between alteplase versus placebo patients. We also used receiver operating characteristic curve to determine the predictive association of early neurological improvement with excellent 3-month functional outcomes (Barthel Index score of 95-100 and modified Rankin Scale score of 0-1), good 3-month functional outcome (modified Rankin Scale score of 0-2), and 3-month infarct volume. Results- There was a significantly greater improvement in the 24-hour median percent change NIHSS among patients treated with alteplase compared with the placebo group (28% versus 15%; P=0.045) but not median delta NIHSS (3 versus 2; P=0.471). Receiver operating characteristic curve comparison showed that percent change NIHSS (ROC_percent) was better than delta NIHSS (ROC_delta) and admission NIHSS (ROC_admission) with regards to excellent 3-month Barthel Index (ROC_percent, 0.83; ROC_delta, 0.76; ROC_admission, 0.75), excellent 3-month modified Rankin Scale (ROC_percent, 0.83; ROC_delta, 0.74; ROC_admission, 0.78), and good 3-month modified Rankin Scale (ROC_percent, 0.83; ROC_delta, 0.76; ROC_admission, 0.78). Conclusions- In the NINDS rt-PA trial, alteplase was associated with a significant percent change improvement in NIHSS at 24 hours. Percent change in NIHSS may be a better surrogate marker of thrombolytic activity and 3-month outcomes.

Abstract WP109: Redefining Early Neurological Improvement After Intravenous Tissue Plasminogen Activator Treatment of Stroke

Background and Purpose: Early neurologic improvement (ENI) in patients treated with alteplase has been shown to correlate with functional outcome. However, the definition of ENI remains controversial and has varied across studies. Current definitions take into account the absolute difference between the admission and 24-hour NIHSS but this difference is usually not reported as a function of the baseline NIHSS. We hypothesized that ENI defined as a percentage change in NIHSS (percent change NIHSS) at 24-hours would better correlate with favorable outcomes at 3 months than ENI defined as the change in NIHSS (delta NIHSS) at 24 hours.

Methods: Retrospective analysis of prospectively collected single center quality improvement data was performed of all acute ischemic stroke (AIS) patients treated with alteplase. Delta NIHSS was defined as the difference in admission and 24-hour NIHSS. Percent change NIHSS was defined as delta NIHSS divided by the admission NIHSS. We examined delta NIHSS and percent change NIHSS in unadjusted and adjusted logistic regression models as predictors of a favorable outcome at 3 months (defined as mRS 0-1).

Results: Among 586 patients with AIS treated with alteplase with admission NIHSS, 24-hour NIHSS, and 3-month mRS available, 194 (33.1%) had a favorable outcome at 3 months. The mean age was 65 years and 59% were men. In fully adjusted models, both delta NIHSS (OR per point decrease 1.27; 95% CI, 1.19– 1.36) and percent change NIHSS (OR per 10 percent decrease 1.17; 95% CI, 1.12-1.22) were associated with favorable functional outcome at 3 months. Receiver operating characteristic (ROC) curve comparison showed that the area under the ROC curve for percent change NIHSS (0.755) was greater than delta NIHSS (0.613) or admission NIHSS (0.694).

Conclusion: Percentage change in NIHSS may be a better surrogate marker of ENI and functional outcome in AIS patients after receiving acute thrombolytic therapy. More studies are needed to confirm our findings.

Abstract WP254: Insular Involvement of Ischemic Stroke Suggests a Cardioembolic Mechanism

Introduction: The insular cortex controls several aspects of vital function including autonomic regulation, and strokes affecting the insula have been associated with dysautonomia, cardiac dysfunction, and arrhythmias. Previous studies have shown an association between insular strokes, elevated troponin levels, and atrial fibrillation (AF). In this study, we aim to determine the association between cardiac biomarkers and insular involvement of the infarct and hypothesize that insular involvement implicates a cardioembolic source.

Methods: We abstracted data from a prospective comprehensive stroke center registry of consecutive patients with a discharge diagnosis of acute ischemic stroke who underwent brain imaging (CT or MRI) and work up to determine stroke mechanism. Data included demographics, clinical baseline variables, laboratory tests (including admission troponin level), and transthoracic echocardiographic variables (regional wall motion abnormalities, ejection fraction, and left atrial volume index), and stroke subtype. Multivariable logistic regression models were built to determine associations between AF, and cardiac biomarkers and insular infarcts.

Results: We identified 1224 patients who met the inclusion criteria; 397 (32.4%) had insular involvement of the infarct. In multivariable models, insular infarcts were associated with AF (adjusted OR 1.73, 95% CI 1.23-2.43, p = 0.001) and left atrial volume index (adjusted OR per standard deviation increase 1.30, 95% CI 1.13-1.49, p = 0.001). There was a trend for association between insular involvement and positive troponin level (adjusted OR 1.45 95% CI 0.91-2.33, p = 0.122) but not with regional wall motion abnormalities (adjusted OR 1.13, 95% CI 0.69-1.84, p = 0.627). Insular involvement was associated with cardioembolic stroke subtype (45.8% vs. 26.7%, p<0.001) but not other stroke subtypes.

Conclusion: The insular cortex is commonly involved in patients with atrial fibrillation and/or atrial dilation and maybe a neuroimaging biomarker of cardioembolic stroke. Larger studies are needed to confirm this association and test anticoagulation therapy in patients with insular infarcts.

Abstract WP106: Redefined Measure of Early Neurological Improvement Shows Treatment Benefit of Intravenous Tissue Plasminogen Activator Treatment in NINDS Rt-PA Acute Stroke Trial at 24 Hours

Background and Purpose: The first of the 2 NINDS Stroke Study trials did not show a significant increase in early neurological improvement (ENI), defined as NIHSS improvement by ≥ 4, with alteplase treatment. We hypothesized that ENI defined as a percentage change in NIHSS (percent change NIHSS) at 24 hours is superior to other definitions in predicting 3-month functional outcomes and using this definition there would be treatment benefit of alteplase over placebo at 24 hours.

Methods: We analyzed the NINDS rt-PA Stroke Study (Parts 1 and 2) trial data. Percent change NIHSS was defined as [(admission NIHSS score–24-hour NIHSS score)x100/admission NIHSS score] and delta NIHSS as (admission NIHSS score–24-hour NIHSS score). We compared ENI using these definitions between alteplase vs. placebo patients. We also used receiver operating characteristic (ROC) curve to determine the predictive association of ENI with excellent 3-month functional outcomes [Barthel Index (BI) score 95 – 100 and modified Rankin scale (mRS) 0-1], good 3-month functional outcome (mRS 0-2) and 3-month infarct volume.

Results: There was a significantly greater improvement in the 24-hour median percent change NIHSS among patients treated with alteplase compared to the placebo group (28% vs. 15%, p = 0.045) but not median delta NIHSS (3 vs. 2, p = 0.471). ROC curve comparison showed that percent change NIHSS (ROC percent ) was better than delta NIHSS (ROC delta ) and admission NIHSS (ROC admission ) with regards to excellent 3-month BI (ROC percent 0.83, ROC delta 0.76, ROS admission 0.75), excellent 3-month mRS (ROC percent 0.83, ROC delta 0.74, ROS admission 0.78), and good 3-month mRS (ROC percent 0.83, ROC delta 0.76, ROS admission 0.78). Percentage change had a stronger association with 90-day infarct volume than delta NIHSS score and both delta NIHSS and percent change in NIHSS were more pronounced with faster treatment times.

Conclusion: In the NINDS rt-PA trial, alteplase was associated with a significant percent change improvement in NIHSS at 24 hours. Percent change in NIHSS may be a better surrogate marker of thrombolytic activity and 3-month outcomes.

Abstract TP421: Cardiovascular Risk in Patients With Symptomatic Intracranial Atherosclerosis: A Post-Hoc Analysis of the SAMMPRIS Trial

Introduction: Previous studies have shown an elevated risk of MI (MI) in patients with symptomatic intracranial atherosclerotic disease (sICAD), but the mediators of increased risk of MI or death in these patients remain uncertain. We aim to determine risk factors associated with MI or death in patients with symptomatic ICAD.

Methods: Patients enrolled in SAMMPRIS had sICAD and were randomized to aggressive medical management (AMM) vs. stenting and AMM. The primary outcome of this post-hoc analysis is MI or vascular death within 2 years of follow-up. We excluded patients who were lost to follow up, had a stroke during follow up, had non-vascular death or death within 30 days of stenting. Patients meeting the inclusion criteria were divided into two groups: those with vs. those without the primary outcome. We used binary logistic regression to determine predictors of incident MI or death within 2 years.

Results: Of the 451 patients enrolled in SAMMPRIS, 350 patients met the inclusion criteria (reasons for exclusion: 4 deaths occurring within 30 days of stenting, 63 with ischemic stroke, 6 with symptomatic hemorrhage, 7 patients with non-cardiovascular death within 2 years, and 21 lost to follow up). At 2 years, 17 patients (4.9%) had MI/death; 10 patients had MI and 7 had cardiovascular deaths. In a multivariable model, factors associated with MI/death were: history of coronary artery disease (adjusted OR 3.19, 95% CI 1.14 - 8.93, p = 0.027) and systolic blood pressure (adjusted OR per 10 mm increase 1.20, 95% CI 0.98 - 1.44, p = 0.080). This risk was abut 24% with both predictors present and 2.8% with them absent (Figure).

Conclusion: Higher systolic blood pressure and pre-existing cardiovascular disease were independently associated with incident MI or vascular death in patients with sICAD, despite medical management. Further studies are needed to confirm this association and test interventions to reduce this risk.

Abstract TP174: Identifying Predictors for Final Diagnosis of Ischemic Events in an Emergency Department Observation Unit

Introduction: Transient neurologic events have high rates of diagnostic uncertainty. Emergency department observation units (ED-OU) allow an accelerated diagnostic work up for suspected transient ischemic attacks (TIAs). However, clinical decision support regarding which patients to admit to these units is lacking. This study aimed to identify clinical features that differentiate true ischemic events from nonischemic transient neurological attacks (NI-TNA) among patients admitted to an ED-OU for suspected TIA.

Methods: A retrospective analysis was performed on consecutive patients admitted to the ED-OU at a single academic center for suspected TIA. Demographics, vascular risk factors, presenting symptoms, and details of the clinical presentation were abstracted from chart review. Final discharge diagnosis was dichotomized to either ischemic event (TIA or minor stroke, TIAMS) or NI-TNA based on the treating vascular neurologist’s final diagnosis. Standard statistical tests were used for comparison testing between the two groups. Significantly different factors with p<0.2 on univariate analysis were carried forward in a multivariable logistic regression model.

Results: Of 186 consecutive patients, 101 (54%) had a final diagnosis of NI-TNA and 85 (46%) of TIAMS. The median population ABCD2 score was 4 [IQR 3-4]. On univariate analysis, older age (63 vs. 70, p<0.01), history of atrial fibrillation (AF) (12% vs. 26%, p=0.01), and facial weakness (5% vs. 14% p=0.03) were associated with TIAMS. Headache (24% vs. 12%, p=0.04) and symptom duration>60min (57% vs. 40%, p=0.02) were associated with NI-TNA. On multivariable analysis, only symptom duration>60 minutes predicted NI-TNA (OR 0.39, p=0.04) and only history of AF (OR 2.53, p=0.03) predicted TIAMS. Facial weakness was strongly predictive of TIAMS (OR 3.22, p=0.05), but not significant.

Conclusion: We identified two clinical features that distinguished TIAMS from NI-TNA among patients admitted to an ED-OU for suspected TIA.These may be helpful in emergency room triage of TIAMS. Data from ED-OU can be used to identify factors associated with cerebral ischemia and improve current care pathways for patients with suspected TIA, so diagnostic evaluation is received in the most appropriate setting.

Abstract TP289: Diagnostic Evaluation of Patients Admitted to Emergency Department Observation Unit for Suspected TIA

Introduction: Emergency department observation units (ED-OU) allow patients with a suspected transient ischemic attack (TIA) an expedited workup without the need for a prolonged inpatient admission. Despite risk stratification scores and physician evaluation, however, the reliability in diagnosis of TIA remains poor, which may lead to unnecessary testing. This study aimed to identify and compare the diagnostic workup between patients with final diagnosis of true vascular events (TIA or minor stroke, TIAMS) versus nonischemic transient neurological attacks (NI-TNA) in suspected TIA patients admitted to an ED observation unit.

Methods: A retrospective analysis was performed on consecutive patients who were admitted to an ED-OU at a single center for suspected TIA. All diagnostic testing obtained during observation stay was abstracted from chart review. Final discharge diagnosis was dichotomized to either TIAMS or NI-TNA. Standard statistical tests were used for comparison testing between the two groups with significance defined as p<0.05.

Results: Of 186 suspected TIA patients admitted to an ED-OU, median ABCD2 score was 4 [IQR 3-4]. Final diagnosis was TIAMS in 85 (46%) patients and NI-TNA in 101 (54%) patients. A total of 182 (98%) patients had non-contrast head CT (NCHCT); 160 (86%) brain MRI; 117 (63%) extracranial vessel imaging; 116 (62%) transthoracic echocardiogram (TTE); and 108 (58%) intracranial vessel imaging. Assessing diagnostic work-up by final diagnosis, TTE (78% vs 40%, p<0.01), and extracranial imaging (75% vs 55%, p<0.01) were more common in patients with TIAMS. Restricted diffusion on MRI (27% vs. 2%, p<0.01) and abnormality on TTE (50% vs. 28% p=0.02) were more common in TIAMS patients. The overall rate of symptomatic stenosis was low: 1 patient had a symptomatic carotid and 4 patients had symptomatic intracranial stenosis.

Conclusion: Extensive diagnostic testing is done on patients with suspected TIA admitted to ED-OU, with more studies acquired on patients with true ischemic events as compared to NI-TNA. As the use of ED-OUs increases, refinement of current diagnostic testing algorithms to reduce workup for cerebrovascular disease among patients with NI-TIA and among different ischemic stroke subtypes is warranted.

Safety and Feasibility of a Rapid Outpatient Management Strategy for Transient Ischemic Attack and Minor Stroke: The Rapid Access Vascular Evaluation-Neurology (RAVEN) Approach

STUDY OBJECTIVE

Although most transient ischemic attack and minor stroke patients in US emergency departments (EDs) are admitted, experience in other countries suggests that timely outpatient evaluation of transient ischemic attack and minor stroke can be safe. We assess the feasibility and safety of a rapid outpatient stroke clinic for transient ischemic attack and minor stroke: Rapid Access Vascular Evaluation-Neurology (RAVEN).

METHODS

Transient ischemic attack and minor stroke patients presenting to the ED with a National Institutes of Health Stroke Scale score of 5 or less and nondisabling deficit were assessed for potential discharge to RAVEN with a protocol incorporating social and medical criteria. Outpatient evaluation by a vascular neurologist, including vessel imaging, was performed within 24 hours at the RAVEN clinic. Participants were evaluated for compliance with clinic attendance and 90-day recurrent transient ischemic attack and minor stroke and hospitalization rates.

RESULTS

Between December 2016 and June 2018, 162 transient ischemic attack and minor stroke patients were discharged to RAVEN. One hundred fifty-four patients (95.1%) appeared as scheduled and 101 (66%) had a final diagnosis of transient ischemic attack and minor stroke. Two patients (1.3%) required hospitalization (one for worsening symptoms and another for intracranial arterial stenosis caused by zoster) at RAVEN evaluation. Among the 101 patients with confirmed transient ischemic attack and minor stroke, 18 (19.1%) had returned to an ED or been admitted at 90 days. Five were noted to have had recurrent neurologic symptoms diagnosed as transient ischemic attack (4.9%), whereas one had a recurrent stroke (0.9%). No individuals with transient ischemic attack and minor stroke died, and none received thrombolytics or thrombectomy, during the interval period. These 90-day outcomes were similar to historical published data on transient ischemic attack and minor stroke.

CONCLUSION

Rapid outpatient management appears a feasible and safe strategy for transient ischemic attack and minor stroke patients evaluated in the ED, with recurrent stroke and transient ischemic attack rates comparable to historical published data.

The Addition of Atrial Fibrillation to the Los Angeles Motor Scale May Improve Prediction of Large Vessel Occlusion

BACKGROUND AND PURPOSE

There is evidence suggesting that Los Angeles Motor Scale (LAMS) ≥ 4 predicts large vessel occlusion (LVO). We aim to determine whether atrial fibrillation (AF) can improve the ability of LAMS in predicting LVO.

METHODS

We included consecutive patients with a discharge diagnosis of ischemic stroke admitted within 24 hours from last known normal time who underwent emergent vascular imaging using a computerized tomography angiography (CTA) of the head and neck. LVO was defined as intracranial internal carotid artery, proximal middle cerebral artery (M1 or proximal M2 segment), or basilar occlusion. LAMS was determined in the emergency department upon arrival. Univariate and multivariable models were performed to identify predictors of LVO and to determine whether AF improves the ability of LAMS to predict LVO.

RESULTS

Among 1,234 patients admitted with ischemic stroke, 862 underwent emergent vascular imaging (69.8%) out of which 374 (43.4%) had evidence of LVO and 207 (24%) underwent mechanical thrombectomy. In multivariable models, predictors of LVO were LAMS (OR 1.42 per one point increase 95% CI 1.29-1.57) and AF (OR 1.95 95% CI 1.26-3.02, P < .001). We developed the LAMS-AF that includes the LAMS score and adds two points if AF is present. In this analysis, LAMS-AF (AUC .78) had improved prediction over LAMS (AUC .76) in predicting LVO and lead to reclassification of 8/68 patients (11.8%) with LAMS = 3 group into the high-risk LVO group.

CONCLUSION

In patients with LAMS = 3, using the LAMS-AF score may improve the ability of LAMS in predicting LVO. Larger studies are needed to confirm our findings.

Abstract TP280: Triage and Outpatient Evaluation of Emergency Department Patients With TIA and Minor Stroke: Rapid Access Vascular Evaluation-Neurology (RAVEN)

Introduction: The timely evaluation of TIA and minor stroke (TIAMS) is important, but whether TIAMS patients with no debilitating deficits should be admitted or not remains unsettled. We piloted a clinical protocol to assess the feasibility and safety of discharging selected TIAMS patients without disabling deficits from the Emergency Department (ED) to a rapid outpatient stroke clinic: Rapid Access Vascular Evaluation-Neurology (RAVEN).

Methods: RAVEN was created as a specialized outpatient neurology clinic for TIAMS patients discharged within 24 hours from the ED at an urban quaternary academic medical center. Patients were first screened in the ED by a neurologist and selected using a decision tool identifying presumed low-risk TIAMS seen in the ED. Criteria included medical (e.g. National Institute of Health Stroke Scale of 5 or less, no disabling deficit, no fluctuating or recurrent symptoms over past month, no thrombolytic agent given, negative CT for hemorrhagic stroke, no new onset atrial fibrillation, blood pressure not over 180/110), as well as social criteria (e.g. patient ability to follow-up within 24 hours). Doppler ultrasound to exclude intracranial and extracranial stenosis, along with neurology re-evaluation was performed as part of RAVEN follow-up. Sample population was evaluated for rates of noncompliance with post-ED follow-up and need for hospitalization from clinic. Final diagnosis was also tabulated.

Results: Between December 2016 and June 2018, 162 TIAMS patients seen in the ED were recommended for RAVEN utilizing the decision tool. Of these patients, 153 (94.4%) were evaluated within 24 hours of ED discharge. Two patients (1.3%) who received outpatient evaluation required hospitalization; 101 (66%) of these patients had a final diagnosis of TIAMS. Other common diagnoses included peripheral neuropathy (15%), migraine (12.5%) and seizure/recrudescence (4%).

Conclusions: Our pilot data suggests that for a subset of TIAMS patients, rapid outpatient evaluation may be a feasible and safe strategy for TIAMS management. Future work exploring such strategies may improve TIAMS outcomes, reduce ED and inpatient crowding, and offer reductions in healthcare costs associated with TIAMS care.

Abstract TP277: A Hospital’s Perspective: Economic Evaluation of Hospitalization vs Rapid Outpatient Evaluation for TIA and Minor Strokes

Introduction: Patients presenting to emergency departments (ED) with TIA and minor strokes (TIAMS) are often admitted for expedited evaluation, though outpatient care models have been proposed. We piloted a rapid outpatient evaluation protocol for patients presenting with TIAMS within 24 hours of ED discharge. We hypothesized that this approach would reduce hospital costs and length of stay (LOS).

Methods: This analysis looked at patients presenting to our institution’s ED with TIAMS (NIHSS < 5) in calendar year 2017. We compared hospitalization LOS, costs and expected revenues between admitted patients and those referred for rapid outpatient evaluation. Patients eligible for outpatient evaluation were without disabling deficits, recurrent symptoms, new-onset atrial fibrillation, prior carotid imaging with >50% stenosis, and not receiving thrombolysis. Disabling deficits were defined as new gait impairments, significant motor weakness, hemianopia, dysphagia or severe aphasia. Cost data was obtained from our finance department and expected revenue was estimated using Medicare reimbursement data, assuming Medicare-Fee for Service as the primary payer for all patients.

Results: We identified 92 patients referred to our rapid outpatient clinic and 90 admitted patients (mean NIHSS 0.8 vs 1.8 respectively). In comparison to patients who were admitted, patients referred to outpatient evaluation had shorter hospital stays, lower total hospitalization costs, and decreased net-losses after accounting for expected revenue (Table). Only one patient in the outpatient cohort was readmitted for further management. Overall, the one-year pilot cohort averted approximately 138 bed-days and $950,000 in hospitalization costs.

Conclusions: For patients who presented to our ED with TIAMS without disabling deficits, rapid outpatient evaluation reduced hospital LOS and total costs. Further research is needed to incorporate costs to payers and patients.

Can I Send This Patient with Stroke Home? Strategies Managing Transient Ischemic Attack and Minor Stroke in the Emergency Department

BACKGROUND

While transient ischemic attack and minor stroke (TIAMS) are common conditions evaluated in the emergency department (ED), there is controversy regarding the most effective and efficient strategies for managing them in the ED. Some patients are discharged after evaluation in the ED and cared for in the outpatient setting, while others remain in an observation unit without being admitted or discharged, and others experience prolonged and potentially costly inpatient admissions.

OBJECTIVE OF THE REVIEW

The goal of this clinical review was to summarize and present recommendations regarding the disposition of TIAMS patients in the ED (e.g., admission vs. discharge).

DISCUSSION

An estimated 250,000 to 300,000 TIA events occur each year in the United States, with an estimated near-term risk of subsequent stroke ranging from 3.5% to 10% at 2 days, rising to 17% by 90 days. While popular and easy to use, reliance solely on risk-stratification tools, such as the ABCD2, should not be used to determine whether TIAMS patients can be discharged safely. Additional vascular imaging and advanced brain imaging may improve prediction of short-term neurologic risk. We also review various disposition strategies (e.g., inpatient vs. outpatient/ED observation units) with regard to their association with neurologic outcomes, such as 30-day or 90-day stroke recurrence or new stroke, in addition to other outcomes, such as hospital length of stay and health care costs.

CONCLUSIONS

Discharge from the ED for rapid outpatient follow-up may be a safe and effective strategy for some forms of minor stroke without disabling deficit and TIA patients after careful evaluation and initial ED workup. Future research on such strategies has the potential to improve neurologic and overall patient outcomes and reduce hospital costs and ED length of stay.

Abstract WP170: Infections Present on Admission and Stroke in the Young

Background and Purpose: Antecedent infections have been identified as possible risk factors and triggers for stroke, while infections after stroke lead to worse outcomes. The impact of infections present at the time of admission (IPOA) has not been well characterized. We hypothesized that IPOA would be associated with stroke severity and outcomes in young stroke patients.

Methods: A retrospective review of consecutive ischemic stroke patients aged 18-40 years admitted between January 2008 and June 2014 was performed. IPOA were defined as present if the infection was diagnosed within the first 24 hours of admission. The primary outcomes were stroke severity using the National Institutes of Health Stroke Scale (NIHSS) and poor functional outcome at discharge (modified Rankin Scale (mRS) 3-6)).

Results: Of 235 patients, 41 (17.4%) had IPOA. Patients with IPOA were more likely to be women (87.8% vs. 51.0%; p<0.0001), younger (30 vs. 34 years; p=0.0317) and to have a higher NIHSS (median 4 vs. 2; p=0.029). In the overall sample, IPOA, age, and female sex were associated with poor outcome. The effect of age on the relationship between IPOA and outcomes appeared to be an interaction, however, the sample size is small; therefore analyses stratified on age were conducted to assess the relationship between IPOA and outcomes. Among patients 18-30, those with IPOA had NIHSS scores 6 points higher than those without IPOA after adjusting for age and sex (p=0.0039), whereas there was no relationship between IPOA and NIHSS in patients > 30 years. In patients 18-30, after adjusting for age, sex, and NIHSS, IPOA was associated with a greater odds of poor outcome (OR 3.69, 95%CI 1.20-11.3); NIHSS was not associated with mRS 3-6 (OR 1.00, 95%CI 0.99-1.01). IPOA was not significantly associated with poor outcome after adjusting for age, sex and NIHSS in patients >30 years (OR 1.29, 95%CI 0.48-3.51).

Discussion: Infections present at time of admission in young stroke patients are closely associated with NIHSS and subsequent poor outcomes at discharge. Further studies are needed to understand the role of infection and whether infections moderate the effect of stroke severity on stroke outcomes in young patients.