Change In NIHSS Research Articles

The move to 24/7 mechanical thrombectomy provision for ischaemic stroke: an observational study of the impact on referrals, activity, procedural efficacy, and safety at a supra-regional centre.

Health systems are striving to improve delivery of mechanical thrombectomy (MT) for ischaemic stroke. With the move to 24/7 provision, we aimed to assess (1) the change in referral and procedural frequency and timing, (2) reasons referrals did not proceed to MT, and (3) nocturnal procedural efficacy and safety. This was an observational study comparing 12-month data for an extended daytime service (2021/2022, hours, 0800-2000) to that for a 12-month period delivering 24/7 cover (2023-2024). Nocturnal and daytime outcomes (rate of recanalisation using modified TICI scoring), extent of postprocedural infarction (using ASPECTS grading), rate of early neurological improvement (using 24-h NIHSS change), 90-day mortality, and complicating symptomatic intracranial haemorrhage (SICH) in the latter period were compared. Both referrals (432 to 851) and procedural caseload (191 to 403) approximately doubled with the move to 24/7 cover; 36% of procedures occurred overnight (n= 145). The dominant reasons for referrals not proceeding to MT were a large core infarct (n= 144) or absence of a large vessel occlusion on baseline imaging (n= 140). There were no significant differences in successful recanalisation (TICI 2B/3: 85.5% vs 87.1%, P= .233), rates of postprocedural ASPECTS≥7 (74.9% vs 75.8%, P= .987), early neurological improvement (NIHSS reduction ≥30%: 43.4% vs 42.4%, P= .917), 90-day mortality (19.6% vs 18.6%, P= .896), or SICH (1.9% vs 4.1%, P= .214) obtained for daytime vs nighttime hours. 24/7 MT provision has resulted in a rapid rise in the number of patients who may benefit from MT. This service can be provided with an acceptable safety profile during nighttime hours in a high-volume comprehensive UK centre.

Pulsed field ablation of atrial fibrillation using a large area focal catheter with a novel contact detection algorithm. A first-in-human experience using the QuickShot catheter

Abstract Background/Introduction Pulsed field ablation (PFA) is emerging as a safe and effective alternative energy modality for cardiac ablation. Data have shown that while tissue contact is critical for PFA, the amount of contact force is less important. Single-shot catheters have shown comparable results to current thermal methods for pulmonary vein isolation (PVI), however, are limited to anatomical-based ablation strategies and have limited ability to detect tissue contact. The investigational QuickShot™ large-area focal catheter (Galvanize Therapeutics, Redwood City, CA) combines high-density mapping with large-area focal ablation guided by contact detection. Purpose The QuickShot PEF-AF study was a prospective, single-arm, first-in-human study performed at a single European center to evaluate the safety and performance of the QuickShot catheter (see Figure 1, panel A) combined with the CE-marked CENTAURI™ System (Galvanize Therapeutics, Figure 1, panel B) for catheter ablation of atrial fibrillation (AF). Methods Subjects with paroxysmal or persistent AF underwent a PVI procedure under deep sedation (fentanyl, midazolam, propofol) guided by Rhythmia™ HDx (Boston Scientific, Marlborough, MA, Figure 1, panel D). Irrigation was set to a constant 6 mL/min during the procedure. Focal, monopolar, biphasic PFA lesions were delivered asynchronously at 33 Amps and a 10 mm inter-lesion spacing (center to center with 10 mm lesion tag size). Catheter-tissue contact was confirmed by ICE/fluoroscopy and a novel impedance-based contact detection system (Figure 1, panel C). The acute performance endpoint was PVI, assessed by entrance and exit block using high-density mapping. Procedural safety assessments included microbubble detection via ICE, induction of VT/VF, muscle stimulation, phrenic nerve function, and NIHSS post-procedure. Results Twenty (20) subjects (60% PAF, 60 ± 12 years, 75% male, 4.3 ± 0.52 cm LA AP diameter) were enrolled and treated. Acute PVI was achieved in 100% of patients and targeted PVs (82/82), with first-pass isolation in 88% of targeted PVs. The PVI time was 31 ± 10 min with 46.7 ± 11.4 PFA applications. There were no device- or procedure-related adverse events, and no documented incidence of microbubble formation, arrhythmia induction, muscle stimulation, phrenic nerve dysfunction, esophageal injury, or change in NIHSS post-procedure. Conclusion The QuickShot catheter enables safe and effective large-area focal PFA for subjects requiring PVI. The catheter design enables efficient and flexible focal lesion placement with the ability to ensure adequate apposition to targeted tissues using its novel contact detection algorithm. Future studies will investigate the use of this novel catheter for PFA strategies beyond PVI.

Abstract WP208: Infarction Size Affects Clinical Outcomes in Emergent Carotid Artery Stenting With Mechanical Thrombectomy

Background: Management of large vessel occlusion with extensive ipsilateral internal carotid artery (ICA) occlusion is unknown. We evaluated patients who underwent emergent carotid artery stenting (CAS) of the ICA with mechanical thrombectomy (MT). Methods: We retrospectively collected baseline demographic, clinical, and radiographic data on 27 patients who presented as a stroke alert within 24 hours of symptoms and had extensive (from bifurcation to distal ICA) occlusion by computerized tomography angiography from 2019-2023 at our institution. All patients underwent CAS with MT and received dual antiplatelet therapy. We measured outcomes by: (1) development of symptomatic ICH at 24 hours, (2) mortality, (3) Modified Rankin Scale (mRS) at 90 days, and (4) change in NIHSS at 24 hours. Baseline characteristics were reported by descriptive statistics. Statistical analyses were completed using Fisher’s exact test, Wilcoxon rank sum test, and logistic regression. Differences were statistically significant at p < 0.05. Results: The mean age for our cohort was 64.5 ± 10.62 and nine patients were females (33.3%). Sixteen had M1 (59.3%) while 10 had M2 occlusion (37%), 14 patients received IV tPA (51.9%), and mean NIHSS at presentation was 15.6 ± 5.99. All patients achieved TICI 2b or TICI 3 recanalization. In our cohort, patients with lower ASPECT score 7.4 ± 1.8 compared to those with higher ASPECT score 9.0 ± 1.0 were more likely to have symptomatic ICH ( p = 0.032), and higher odds of mortality OR = 0.496, 95% CI (0.261-0.945). The development of symptomatic ICH at 24 hours following procedure was associated with severe disability (mRS 4-6) at 90 days ( p = 0.032). Administration of intravenous tPA was significantly associated with improvement of 4 or more points on NIHSS at 24 hours ( p = 0.032), but not with symptomatic ICH ( p = 0.419). Age, NIHSS at presentation, systolic blood pressure, and diabetes mellitus were not associated with mortality or symptomatic ICH. Conclusion: The area of infarction at the time of presentation (ASPECT score) is an essential factor in stratifying patient selection for emergent CAS during MT in extensive internal carotid artery occlusion. Further studies are needed to evaluate infarction size for safe interventions.

Abstract TMP47: Identifying and Categorizing Delays to Endovascular Treatment in Patients With Large Vessel Occlusions

Introduction: Early endovascular treatment (EVT) in patients with large vessel occlusions (LVO) is associated with better outcomes. Identifying and categorizing delays to EVT may reveal areas for improvement. Methods: We prospectively identified all patients who underwent EVT at our hospital between May 2022 - 2023. We determined eight steps in acute care: arrival, imaging, IR activation, ED release, arrival to IR, groin puncture, first pass, and recanalization. We classified patients as delayed if any interval exceeded their rolling six-month median. We created 12 categories and 36 subcategories of delays. We used t-test and odds ratios to compare intervals and outcomes between delayed and non-delayed patients. We analyzed subgroups based on causes of delay and location of presentation. Results: Out of 183 LVO patients who underwent EVT, 111 (61%) were delayed. There were no significant differences in age, gender, last known normal to arrival, NIHSS, thrombolytic use, or TICI scale. The delayed group had higher door to groin (99 min), door to device (126 min), and door to recanalization (159 min) compared to the non-delayed group (40, 65, 81 min; p < 0.001). The most common causes of delay were: general case complexity (20%), which was associated with higher door to imaging (59 min, p < 0.001) and imaging to IR activation (37 min, p = 0.03); after hours presentation (19%), which was associated with higher door to imaging (53 min, p = 0.02) and imaging to IR activation (36 min, p = 0.01); and procedural complexity (18%) which was associated with higher groin to device (34 min, p < 0.001) and device to recanalization (53 min, p < 0.001) when compared to other causes of delay. Between the delayed and non-delayed group, there was no significant difference in the length of stay, change in NIHSS at discharge, in-hospital mortality, disposition, or 90-day mRS. Subgroup analysis showed a trend towards higher mortality in delayed patients who presented after hours (OR 3.60 (CI) 0.92-14.10) or in-hospital (OR 2.41 (CI) 0.57-10.19). Conclusions: We determined seven intervals where delays can occur between arrival and recanalization of LVO patients. We created a system for categorizing delays that showed areas for improvement including after hours and in-hospital stroke evaluation.

Abstract WP25: Eptifibatide in Acute Ischemic Strokes Without Large Vessel Occlusions

Background: Platelet glycoprotein IIb/IIIa inhibitors are currently being researched for patients with acute ischemic stroke (AIS), however there is no consensus on which inhibitor or dose is both safe and effective. Tirofiban has recently been studied, however it was associated with an increased risk of intracranial bleeding. In this study we share our experience using eptifibatide given it has shown to be as effective as tirofiban with a better safety profile. Methods: In this multi-center retrospective analysis, we screened 102 patients who received an eptifibatide bolus of 135 mcg/kg followed by 0.5 mcg/kg/min infusion and 332 patients treated with usual stroke care between December 2022 and May 2023. Patients were excluded if the NIHSS on presentation but within 24 hours of last known well was less than 3 or if the patient had a large vessel occlusion (LVO). There were 7 and 31 patients included in the eptifibatide and usual care group respectively. Our primary endpoint was change in NIHSS from admission to discharge. Our safety endpoints were symptomatic ICH and any ICH. Results: No patients included in the study experienced a symptomatic ICH. The median time of eptifibatide infusion was 24 hours with some patients receiving the infusion for multiple days. Conclusion: While larger studies are needed to confirm our findings, eptifibatide may be safe and effective in the treatment of AIS without LVO.

Abstract TP253: Early Neurological Deterioration Following Small Subcortical Infarcts: A Systematic Review and Meta-Analysis

Background and Objectives: Acute small subcortical infarcts (SSI) result in high rates of early neurological deterioration (END) despite best medical management. Those with SSI-related END have worse functional outcomes after stroke leading to increased morbidity. Presently, it is unknown in a robust manner the incidence or risk factors for END within this demographic. The aim of this study was to perform a systematic review and meta-analysis to understand the incidence and risk factors of SSI-related END. Methods: We searched PubMed, Cochrane Library, and Google Scholar between January 1, 2000, and June 1, 2022, including both retrospective cross-sectional and prospective observational studies. The primary outcome was development of END based on publishing authors’ definition. Abstracted data included age, sex, cohort size, diagnoses of hypertension, hyperlipidemia, diabetes mellitus, study definition of END and SSI, and presence of branch atheromatous disease (BAD) and lesion diameter. Results: We identified 31 studies enrolling 6376 patients. Most studies were conducted in East Asia (27/31, 87%) and had a least some concern for risk of bias. Funnel plot illustrated a high level of publication bias favoring high incidence studies. END was commonly defined as ≥ 2 overall NIHSS change or ≥ 1 motor change within 3 to 7 days from admission (average: 5 days). A pooled proportion of END was 22% (95%CI 0.19 - 0.25, I2 = 91.2%, 31 studies). Meta-regression identified that female sex [risk ratio (RR) 1.23, 95%CI 1.09-1.39, I2=30.8%, 31 studies], diabetes mellitus (RR 1.16 95%CI 1.01-1.33, I2=38.4%, 30 studies), and BAD (RR 1.99 95%CI 1.61-2.46, I2=50.7%, 17 studies) as risk factors for END. Discussion: Our data identified primarily within an East Asian cohort that risk factors for SSI-related END include diabetes mellitus and branch atheromatous disease with a pooled prevalence of END occurring in 1 in 4 patients. Future studies are needed to understand treatment and preventative strategies for this patient population.

Serum β-synuclein, neurofilament light chain and glial fibrillary acidic protein as prognostic biomarkers in moderate-to-severe acute ischemic stroke

We aimed to assess the prognostic value of serum β-synuclein (β-syn), neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) in patients with moderate-to-severe acute ischemic stroke. We measured β-syn, GFAP and NfL in serum samples collected one day after admission in 30 adult patients with moderate-to-severe ischemic stroke due to middle cerebral artery (MCA) occlusion. We tested the associations between biomarker levels and clinical and radiological scores (National Institute of Health Stroke Scale scores, NIHSS, and Alberta Stroke Program Early CT Score, ASPECTS), as well as measures of functional outcome (modified Rankin Scale, mRS). Serum biomarkers were significantly associated with ASPECTS values (β-syn p = 0.0011, GFAP p = 0.0002) but not with NIHSS scores at admission. Patients who received mechanical thrombectomy and intravenous thrombolysis showed lower β-syn (p = 0.029) und NfL concentrations (p = 0.0024) compared to patients who received only mechanical thrombectomy. According to median biomarker levels, patients with high β-syn, NfL or GFAP levels showed, after therapy, lower clinical improvement (i.e., lower 24-h NIHSS change), higher NIHSS scores during hospitalization and higher mRS scores at 3-month follow-up. Elevated serum concentrations of β-syn (p = 0.016), NfL (p = 0.020) or GFAP (p = 0.010) were significantly associated with 3-month mRS of 3–6 vs. 0–2 even after accounting for age, sex and renal function. In patients with moderate-to-severe acute ischemic stroke, serum β-syn, NfL and GFAP levels associated with clinical and radiological scores at different timepoints and were able to predict short- and middle-term clinical outcomes.

Abstract 279: Angiography Utilization in LVO Drip‐and‐Ship Patients: Comparing Air and Ground

Introduction Patients with acute intracranial large vessel occlusions (LVO) in the drip‐and‐ship model are transferred from an outside hospital (OSH) to a comprehensive stroke center (CSC) after receiving thrombolysis. In our practice, while most of these patients go directly to the angiography suite (DTA), some of them spontaneously recanalize and may not need mechanical thrombectomy (MT). We aim to assess the impact of transport modality on the efficacy of tPA‐induced recanalization by assessing rates of groin puncture, MT, and clinical outcomes. Methods We retrospectively evaluated 270 patients from 2020‐mid 2022 with either confirmed or suspected LVO in our healthcare network who received tPA at an OSH and were transported by either air or ground transport to our spoke hospital (CSC) with the intention of receiving MT. We compared baseline characteristics and then applied linear regression with propensity score matching to compare the air and ground groups. Between the two groups, we looked at the difference in the rates of change in NIHSS between OSH and TTH (delta NIHSS), groin puncture rates, rate of receiving mechanical thrombectomy (MT), rate of angiography alone without MT, and modified Rankin Scale (mRS) at 90 days. Results Of the 270 patients evaluated, 1 patient was excluded due to missing transport modality. 130 (48.33%) were transferred by ground transport and 139 (51.67%) by air. Baseline characteristics were similar between the air and ground groups with the exception of OSH NIHSS which was higher in the air group (13.59±8.3 vs. 10.4±7.81, p<0.001). In a linear regression model, air transport was not a significant predictor of improvement of NIHSS from OSH to CSC (p=0.69, R2=0.002) or groin puncture rate (OR=1.5, 95% CI 0.412‐ 5.471, p=0.54). Of the 198 confirmed LVO on CTA, 47.26% of air patients received MT compared with 48.74% (OR: 1.1, p=0.62) of ground patients. 11.32% of these confirmed LVO patients who were transported by air received angiography without mechanical thrombectomy compared to 11.68% of ground patients (OR: 2.1, p=0.1). A linear regression model with propensity matching did not show transport modality as a predictor of mRS at 90 days (p=0.32, R2=0.14). Conclusion LVO patients who receive tPA and are transferred by air directly to the angiography suite have a higher baseline NIHSS than those transported by ground. Mode of transport does not seem to predict changes in NIHSS or 90 day mRS in this population. Groin puncture, mechanical thrombectomy, and angiography without MT rates are similar between these groups. Mode of transport alone may not influence angiography utilization or clinical outcome so distance between sites and speed of transport should be used to determine whether air or ground is the better choice in each individual case.

Abstract 190: Patient Selection for Intracranial Stenting: Impact on Clinical Outcomes and Procedural Success Rates

Introduction Intracranial atherosclerosis (ICAS) is a leading global cause of stroke. The role of intracranial stenting in ICAS remains uncertain. In the SAMMPRIS trial, patients who had experienced recent TIA/CVA secondary to 70‐99% ICAS demonstrated an increased risk of recurrent stroke when treated with angioplasty and stenting compared to medical therapy alone [1]. The VISSIT trial found an increased 12‐month risk of TIA/CVA in the same territory, as well as an increased 30‐day risk of any TIA/CVA, when a stenting was used in patients with ICAS [2]. Additionally, the recent CASSISS trial demonstrated that adding percutaneous transluminal angioplasty and stenting (PTAS) to medical therapy did not significantly affect the risk of stroke or death within 30 days or stroke beyond 30 days through 1 year in patients TIA/CVA secondary to symptomatic ICAS [3]. However, the WEAVE trial demonstrated that using the Wingspan stent for ICAS resulted in a low periprocedural complication rate and excellent safety profile [4]. Subsequently, the WOVEN study provided a 1‐year follow‐up to WEAVE. It presented a more homogeneous patient group than in prior studies, and demonstrated a relatively low 8.5% 1‐year rate of stroke and death in stented patients [5]. Currently underway, the Angioplasty and Stenting for Patients With Symptomatic Intracranial Atherosclerosis Clinical trial (NCT02689037) aims to determine whether PTAS combined with medical treatment is superior to medical treatment alone in preventing stroke and death events in patients with symptomatic ICAS [6]. The purpose of this case series is to provide an overview of the procedural and clinical outcomes of patients who underwent stenting for symptomatic ICAS. Methods We reviewed a database of all interventional procedures conducted at our institution to identify patients who underwent intracranial stenting from 2013 and 2022 for symptomatic ICAS. Electronic medical records were assessed, and data on patient demographics, comorbidities, lesion characteristics, and clinical outcomes were extracted. The outcomes of interest included successful stent placement, restoration of blood flow, procedural complications, symptomatic improvement, change in NIHSS, and mortality and stroke within one year. Descriptive statistics were used, summarizing continuous variables as means and standard deviations, and categorical variables as frequencies and ranges. Results Between 2013 and 2022, 35 patients underwent intracranial stenting for symptomatic ICAS. Procedurally, all patients had successful stent placement and restoration of blood flow. Six patients (17.1%) experienced perioperative complications including stent occlusion, bradycardia, and hematoma. Regarding clinical outcomes, 25 patients (71.4%) showed improvement in their TIA/CVA symptoms, including dizziness, weakness, and speech difficulties. Furthermore, 21 patients (60%) had improved NIHSS scores by discharge, 9 patients (25.7%) remained stable, and 4 patients (11.4%) deteriorated. One unrelated mortality was recorded at 1‐year post‐procedure. Conclusion This case series demonstrates the successful and effective restoration of distal blood flow through intracranial stenting for symptomatic ICAS. The low rates of perioperative complications and potential improvements in patients' clinical outcomes suggest the need for further investigation into the patient selection, safety, and effectiveness of intracranial stenting for managing symptomatic ICAS.

Abstract Number ‐ 53: Endovascular therapy versus medical management for mild strokes due to medium and distal vessel occlusions

Introduction Distal and medium vessel occlusion (DMVO) strokes account for 25–40% of all acute ischemic strokes1 and are associated with long‐term disability in as many as 77% of patients2. Approximately one third of DMVO stroke patients have a low National Institute of Stroke Scale (NIHSS) (≤6)3. Multiple randomized controlled trials showed superiority of endovascular therapy (EVT) over best medical management (BMT) in patients presenting with proximal LVO involving the anterior circulation and NIHSS of >64. The efficacy and safety of EVT for DMVO patients is uncertain, especially in patients with low NIHSS. A better understanding of this issue is important because many patients with DMVO and low NIHSS scores suffer disabling deficits while procedural risk are increased due to the target vessels’ small caliber, tortuosity, and thinner walls. We conducted a retrospective single center study to compare clinical and safety outcomes of DMVO patients with NIHSS ≤ 6 that were treated with EVT versus BMT. Methods We retrospectively analyzed consecutive patients with acute mild (NIHSS ≤ 6) DMVO stroke that presented between January 2018 and December 2021. We defined DMVO stroke as stroke caused by an occlusion of the M2‐4 segments of the MCA, A2‐3 segments of the ACA, P1‐2 segments of the PCA. Outcomes of interest were the NIHSS at day one and at discharge, the change in NIHSS from admission to discharge (ΔNIHSS) and the mRS at 90‐days. Safety outcomes were clinical deterioration, defined as an increase in the NIHSS by 4 or more points and the occurrence of symptomatic intracranial hemorrhage (sICH), defined as any type of ICH causing an increase in the NIHSS by 4 or more points. Results Overall, we included 80 subjects that fulfilled our study criteria. Of these, 41 were treated with BMT and 39 were selected to undergo EVT. Clinical characteristics of subjects selected for BMT versus EVT were overall similar except for more frequent diabetes (p = 0.035) and antiplatelet use (p = 0.045) as well as less frequent anticoagulation (p = 0.019) in the BMT group. Moreover, subjects selected for EVT had a lower pre‐stroke mRS (p = 0.025) and a lower ASPECT score on the admission head CT (p = 0.044). Overall, there was no statistical difference between NIHSS at day 1 (p = 0.654), NIHSS at discharge (p = 0.244), and ΔNIHSS from Day 0 to Day 1 (p = 0.08). There was further no difference in the discharge (p = 0.895) and 3‐month (p = 0.957) mRS between groups. Regarding safety outcomes, there was no difference in the number of all types of ICHs combined between the two groups (p = 0.229) and there was no difference in the number of patients who had clinical deterioration (p = 0.258). Conclusions Our analysis shows that in patients who present with mild DMVO strokes, early and 3‐month clinical outcomes were comparable between EVT and BMT groups. Moreover, risk of intracranial hemorrhage, clinical deterioration, and death were similar between groups. Nevertheless, given the low number of subjects, our analysis did not reach statistical significance and further large‐scale studies are required to clarify efficacy and safety of EVT versus BMT in DMVO patients with low clinical deficit severity

Abstract Number: LBA14 Incidence of Intracranial Hemorrhage & Clinical Outcomes in Fast Versus Slow Progressors as per ASPECTS

Introduction Heterogeneity of collateralization in patients with acute ischemic stroke (AIS) is a marker of fast versus slow progression of penumbral consumption and infarct expansion. Our aim was to evaluate the relationship between time‐dependent stroke progression and incidence of intracranial hemorrhage (ICH) and acute neurological deficits. Methods Retrospective chart review of patients presenting with anterior circulation large vessel occlusion (LVO)‐associated AIS at our comprehensive stroke center with 24 hours last known normal (LKN) who underwent endovascular thrombectomy (EVT) without intra‐arterial thrombolytics or non‐thrombolytics were included. We used Alberta Stroke Program Early CT Score (ASPECTS) on initial non‐contrast CT to identify slow versus fast progressors. ASPECTS < = 7 was defined as fast progressor. Subgroup analysis was performed based on LKN < 3 hours, 3–9 hours, and 9–24 hours. We evaluated rate of hemorrhagic transformation using ECASS‐3 criteria and determined change in NIHSS from baseline to discharge. Mann‐Whitney U test and Fisher exact test statistic with Social science statistics software used for data analysis. Results From September 2019 to December 2021, out of 268 subjects who underwent EVT, 48 met inclusion criteria. Mean age was 65.29 (95% CI 61.32, 69.27), and median presenting NIHSS was 16 (95% CI 14.39, 18.40). Mean ASPECTS was 7.71 (95% CI 7.21, 8.20). There was significant difference is hemorrhagic transformation rate between ASPECTS >7 and < = 7 (Fisher value = 0.018). Sample size was not large enough to perform subgroup analysis based on last known normal. However, there was a trend towards increase in hemorrhagic transformation rate with greater time from last known well at same ASPECTS score. Slow progressors also had a significant improvement in presenting and discharge NIHSS as compared to fast progressors (z‐score is ‐3.10, p‐value is 0.002). Conclusions Our study suggests that ASPECTS score as assessed in different time windows to differentiate fast versus slow progressors is not only a predictor of clinical outcome, but also independently associated with risk of hemorrhagic transformation. Larger, prospective studies are needed to validate our results.

Abstract 61: Retrospective Safety Study Of Low Intensity Monitoring In Cases Of Acute Ischemic Stroke That Received Thrombolytic Therapy

Introduction: It is standard to observe acute ischemic stroke (AIS) patients under high intensity monitoring (HIM) for the first 24 hours after intravenous thrombolysis (IVT). However, HIM is resource intensive and may not be necessary for every AIS patient. This study evaluates the safety and efficacy of low-intensity monitoring (LIM) for a subset of low-risk AIS patients who received IVT. Methods: Data from patients discharged from 2 hospitals between April 2020-April 2022 admitted to LIM post-IVT were retrospectively abstracted from patient records. Patients under age 18, arrival NIHSS ≥17, presence of large vessel occlusion, need for endovascular therapy, uncontrolled high blood pressure or unstable neuro exam (change in NIHSS of 4 or more within the 1st hour) were excluded. Primary outcomes were transfer back to HIM, instances and treatment of high blood pressure (HBP), in-hospital stroke mortality, discharge disposition and 90-day mRS. Population characteristics of age, sex, race, medical history, transfers to hub prior to LIM admission, discharge mRS and door-to-needle times were also examined. Results: Among 173 patients who met inclusion criteria, 1 (.6%) patient was transferred back to HIM and no patients died from in-patient stroke-related causes. Most patients were discharged home (80.9%) with a median 90-day mRS score of 1 (IQR: 0, 2, Table 1). Conclusion: LIM can reduce resource intensity of stroke care and free up critical care beds, which can result in less cost for the hospital and the patient. We conclude that LIM is safe and effective and could be the standard of care for low-risk AIS patients treated with IVT.

Abstract TP10: Realtime Tenecteplase Recanalization Rates And Clinical Outcomes In Patients With Medium Vessel Occlusion Stroke

Introduction: The goal of this study was to evaluate recanalization rates, incidence of hemorrhagic transformation, and clinical outcomes in patients with medium vessel occlusion (MVO) strokes receiving tenecteplase (TNK) and endovascular treatment (EVT) to add to the growing fund of knowledge of TNK in AIS. Methods: We conducted a retrospective cohort study of prospectively collected AIS patients who received TNK and EVT from October 2020 to June 2022 at our comprehensive stroke center. We included subjects with MVO defined as occlusion of the M2 segment or more distal of the middle cerebral artery without involvement of the M1 segment, A1 segment or more distal of the anterior cerebral artery, or P1 segment or more distal of the posterior cerebral artery. Patients receiving intra-arterial thrombolytics or non-thrombolytics were excluded. We defined successful recanalization as Modified Thrombolysis in Cerebral Infarction (mTICI) 2b or greater and symptomatic hemorrhage as change in NIHSS ≥ 4 with temporally associated hemorrhage. Hemorrhagic transformation was classified using ECASS-3 criteria. Social science statistics software was used for data analysis. Results: Out of 77 patients who received TNK and EVT, 16 subjects had MVO and were included in analysis. Mean age was 68.56 (95% CI 60.20, 76.93). Fifty six percent (n=9) of subjects were female. Median presenting NIHSS was 10.5 (95% CI 7.17, 14.07). Median 90 day mRS was 1 (95% CI 0.76, 2.62). No subject recanalized prior to EVT. Hemorrhagic transformation occurred in 43.75% (n=7) of subjects, and symptomatic intracerebral hemorrhage (ICH) occurred in 1 subject (6.25%) with PH-2. There was no ICH in subjects who did not recanalize post-EVT (n=3). No significant change was found from baseline NIHSS compared to discharge NIHSS (U=95.5, z=1.21, p=0.11). Conclusions: TNK in MVO may be associated with increased risk of hemorrhagic transformation. However, given that all subjects underwent EVT and the known incidence of post-procedural contrast staining on CT, the incidence of asymptomatic hemorrhagic transformation may be overestimated. This is further supported by good clinical outcomes and low incidence of symptomatic ICH.

Abstract WP128: Incidence Of Intracranial Hemorrhage And Clinical Outcomes In Fast Versus Slow Progressors As Defined By Aspects

Introduction: Heterogeneity of collateralization in patients with acute ischemic stroke (AIS) is a marker of fast versus slow progression of penumbral consumption and infarct expansion. Our aim was to evaluate the relationship between time-dependent stroke progression and incidence of intracranial hemorrhage (ICH) and acute neurological deficits. Methods: Retrospective chart review of patients presenting with anterior circulation large vessel occlusion (LVO)-associated AIS at our comprehensive stroke center with 24 hours last known normal (LKN) who underwent endovascular thrombectomy (EVT) without intra-arterial thrombolytics or non-thrombolytics were included. We used Alberta Stroke Program Early CT Score (ASPECTS) on initial non-contrast CT to identify slow versus fast progressors. ASPECTS <=7 was defined as fast progressor. Subgroup analysis was performed based on LKN <3 hours, 3-9 hours, and 9-24 hours. We evaluated rate of hemorrhagic transformation using ECASS-3 criteria and determined change in NIHSS from baseline to discharge. Mann-Whitney U test and Fisher exact test statistic with Social science statistics software used for data analysis. Results: From September 2019 to December 2021, out of 268 subjects who underwent EVT, 48 met inclusion criteria. Mean age was 65.29 (95% CI 61.32, 69.27), and median presenting NIHSS was 16 (95% CI 14.39, 18.40). Mean ASPECTS was 7.71 (95% CI 7.21, 8.20). There was significant difference is hemorrhagic transformation rate between ASPECTS >7 and <=7 (Fisher value=0.018). Sample size was not large enough to perform subgroup analysis based on last known normal. However, there was a trend towards increase in hemorrhagic transformation rate with greater time from last known well at same ASPECTS score. Slow progressors also had a significant improvement in presenting and discharge NIHSS as compared to fast progressors (z-score is -3.10, p-value is 0.002). Conclusion: Our study suggests that ASPECTS score as assessed in different time windows to differentiate fast versus slow progressors is not only a predictor of clinical outcome, but also independently associated with risk of hemorrhagic transformation. Larger, prospective studies are needed to validate our results.

530: EVALUATION OF ALTEPLASE INFUSION DELAY FOLLOWING BOLUS AND IMPACT ON OUTCOMES IN ISCHEMIC STROKE​

Introduction: Alteplase is most beneficial when given early in acute ischemic stroke (AIS) and therefore a door-to-needle time (DTN) of less than 30 minutes is recommended by the AHA. Institutions may administer the alteplase bolus immediately following results of the non-contrast CT scan, however the start of alteplase infusion may be delayed for various reasons. Delays between the alteplase bolus and infusion can result in reduced drug concentration due to a short half-life (5 minutes), but it is unknown how a prolonged delay between bolus and infusion impacts outcomes. We performed a single health-system retrospective assessment determine if a delay of more than 5 minutes between alteplase bolus and infusion impacts outcomes in patients with AIS. Methods: Adult patients who received alteplase for the treatment of AIS between March 2015 through October 2021 were included. Patients were excluded if they received alteplase at an outside hospital; underwent a mechanical thrombectomy; lacked documentation of admission or discharge NIHSS; or if pregnant. The primary outcome evaluated the change in the NIHSS from admission to discharge in patients with less than or equal to a five-minute difference compared to patients with greater than a five-minute difference from alteplase bolus to infusion. Secondary outcomes evaluated admission NIHSS compared to 90-day mRS, discharge location, in-hospital mortality, and 90-day mortality. Results: 1229 patients were included. 280 patients had a bolus to infusion delay of > 5 minutes and 949 patients had a delay of ≤ 5 minutes. There was no difference in the change in NIHSS from admission to discharge (decrease of 3 points). There was also no difference in the secondary outcomes except for 90-day mortality which was statistically higher in the group of patients with a bolus to infusion delay (6.8% vs 3.3% p-value: 0.009). The difference in 90-day mRS (n=470) was not statistically significant but did show a trend towards worse outcomes in patients with an initial NIHSS of 5-14. Conclusions: Delay in alteplase infusion following bolus did not consistently show worse patient outcomes but did show an increase in 90-day mortality and mRS. Interpretation of these study results should be taken with caution due to the retrospective nature and missing data points for 90-day mRS.

ADC measurement relevance to predict hemorrhage transformation after mechanical thrombectomy

BackgroundADC (apparent coefficient diffusion) value has been known to predict hemorrhage transformation (HT) after thrombolysis and recently, after mechanical thrombectomy (MT). We aimed to evaluate that utility separately in basal ganglia and superficial territory. We used HT occurrence with or without NIHSS change as primary outcome measures. MethodsThis single-center retrospective study included consecutive stroke patients receiving MT for internal carotid artery (ICA) or middle cerebral artery (M1 or M2) occlusion. In patient with or without HT, using the Heidelberg Bleeding Classification, on follow-up CT scan at 24–48 h, we assessed the ADC value separately in basal ganglia and superficial territory on MRI before MT to search for the correlation. Multivariable analysis was performed using variables with significant differences between the HT group and non-HT group. ResultsOne hundred seventeen patients were included in the final analysis. HT distribution was as follows: 9 patients (7.69%) HI1 or 2; 14 patients (11.97%) PH1; 21 patients (17.95%) PH2; 29 patients (24.79%) subarachnoid hemorrhage; and 21 patients (17.95%) symptomatic intracranial hemorrhage (sICH). Mean ADC minimal value in basal ganglia in the HT group was significantly lower than in the non-HT group (377.6 × 10−6 mm2/s [± 52.4] vs 413.3 × 10−6 mm2/s [± 72.5]; p = 0.0229) with an area under the curve (AUC) of 0.6622 (95% CI: 0.5–0.8; p = 0.014). MRI-MT time was significantly longer in the HT group (p = 0.0002), but there was no association between ADC value and onset-MRI or MRI-MT times (Spearman's coefficients <0.7, p > 0.05). Glycemia at admission (>1.5 g/L) (OR = 4.2; 95% CI [1.611; 10.961]) and carotid occlusion (OR = 2.835; 95% CI [1.134; 7.091]) were independently associated with HT. ConclusionsADC value in basal ganglia, unlike brain superficial territory, are correlated to HT risk after MT.

Clinical Efficacy of Cerebrolysin and Cerebrolysin plus Nootropics in the Treatment of Patients with Acute Ischemic Stroke in Vietnam.

To investigate the efficacy and safety of Cerebrolysin and Cerebrolysin plus nootropics in the routine treatment of patients with acute ischemic stroke (AIS). Acute ischemic stroke (AIS) is a leading cause of disability with unmet treatment needs lacking effective drug therapy. Multimodal drugs modulating stroke pathophysiology as Cerebrolysin constitute a good therapeutic option. In this study, we assessed the effects of Cerebrolysin and Cerebrolysin plus nootropics, in comparison with other nootropic drugs alone, on functional, neurological and cognitive recovery of patients with AIS in Vietnam. This non-interventional, controlled, open-label, prospective and multicenter study included 398 AIS patients (234 males) treated with Cerebrolysin (n=190; 20 i.v. infusions of 10 ml), other nootropics (comparator group; n=86), or a combination of both (n=122). The study primary endpoint was the modified Ranking Scale (mRS) score on day 90. Secondary endpoints included study-period change in NIHSS score; percentage of well-recovered (mRS 0-2) patients, the proportion of good NIHSS response (≥6 points) cases, and MoCA scores at day 90; and safety indicators. Compared with other nootropics, both Cerebrolysin and combined therapy induced significant improvements (p<0.001) in: Functional recovery (mRS scores); percentage of well-recovered patients (Cerebrolysin: 81.6%; combination: 93.4%; comparator: 43.0%); neurological recovery (study- period NIHSS change); proportion of good NIHSS responders (Cerebrolysin: 77.5%; combination: 92.5%; comparator: 47.6%); and MoCA scores (Cerebrolysin: 23.3±4.8; combination: 23.7±4.1; comparator: 15.9±7.7). Compared to Cerebrolysin, combined therapy improved (p<0.01) mRS outcomes and NIHSS change, but not MoCA scores, in moderate-severe stroke (NIHSS>11) cases only. No drug-related adverse events were reported. Cerebrolysin alone or combined with other nootropics was effective and safe in routine AIS treatment, during both acute and recovery phases, which supports its use in daily clinical practice. Others: According to the results of this multicenter study, the importance of reducing differences in the treatment regimens of AIS in Vietnam should be further emphasized.

National Institutes of Health Stroke Scale Correlates Well with Initial Intracerebral Hemorrhage Volume

The US Centers for Medicare and Medicaid Services (CMS) currently publicly reports hospital-quality, risk-adjusted mortality measure for ischemic stroke but not intracerebral hemorrhage (ICH). The NIHSS, which is captured in CMS administrative claims data, is a candidate metric for use in ICH risk adjustment and has been shown to predict clinical outcome with accuracy similar to the ICH Score. Correlation between early NIHSS and initial ICH volume would further support use of the NIHSS for ICH risk adjustment. Among 372 ICH patients enrolled in a large multicenter trial (FAST-MAG), the relation between early NIHSS and early ICH volume was assessed with correlation and linear trend analysis. Overall, there was strong correlation between NIHSS and ICH volume, r=0.77 (p<0.001), and for every 10cc increase in ICH the NIHSS increased by 4.5 points. Correlation coefficients were comparable in all subgroups, but magnitude of NIHSS increase with ICH unit volume increase was greater with left than right hemispheric ICH, with presence rather than absence of IVH, with imaging done within the first hour than second hour after last known well, with men than women, and with younger than older patients. Early NIHSS neurologic deficit severity values correlate strongly with initial ICH hematoma volume. As with ischemic stroke, lesion volume increases produce greater NIHSS change in the left than right hemisphere, reflecting greater NIHSS sensitivity to left hemisphere function. These findings provide further support for the use of NIHSS in risk-adjusted mortality measures for intracerebral hemorrhage.

Abstract TP262: Effect Of Prehospital Blood Pressure Fluctuations On Early Neurological Changes In Acute Ischemic Stroke Patients With Large Vessel Occlusion

Introduction: Blood pressure fluctuations in the acute phase of large vessel occlusion (LVO) ischemic stroke are associated with infarct progression and poor outcomes. We evaluated the association of prehospital blood pressure variations on a Mobile Stroke Unit (MSU) with early neurological change. Methods: Prospectively-derived data were analyzed from tPA-eligible LVO patients treated and transported on the MSU, identified by hyperdense artery on CT or arterial occlusion on CTA. Patients were categorized by change in mean arterial pressure (ΔMAP) of &gt; 10 mm Hg vs Δ MAP &lt; 10 mmHg from arrival of MSU on-scene to arrival to the emergency department (ED). A sub-analysis of patients with ΔMAP &gt; 10 mm Hg compared those whose MAP decreased by &gt; 10 mm Hg vs those whose MAP increased by &gt; 10 mm Hg. The primary outcome was 24-hour change in NIHSS. Groups were compared using Chi-square/Fisher’s exact test for categorical variables and Wilcoxon rank sum test for continuous variables. Results: A total of 39 tPA-eligible LVO patients were identified, 19 with ΔMAP &lt; 10mm Hg and 20 with ΔMAP &gt; 10mm Hg. Baseline characteristics were comparable between groups including NIHSS (18.0 [11.0, 21.0] vs 20.0 [16.8, 25.8]) (Table 1). A similar percentage from each group received tPA and thrombectomy. Upon presentation to ED, 7/19 (37%) patients with ΔMAP &lt; 10mm Hg had a 30% improvement in NIHSS, compared to 4/20 (20%) patients with ΔMAP &gt;10mm Hg (p=0.417). The 24-hour change in NIHSS was also similar (ΔMAP &lt; 10mm Hg = 7.0 [3.5, 12.0] vs ΔMAP &gt; 10 mm Hg 10.0 [4.0, 16.0], p=0.517). Among patients with ΔMAP of 10mm Hg group, those with MAP decrease by &gt; 10 mm Hg had a 10 point [7.0, 16.0] improvement in NIHSS vs 6.0 [2.5, 15.0] point improvement in those whose MAP increased by &gt; 10 mm Hg (p=0.169). Conclusion: Though limited by a small sample size, prehospital blood pressure fluctuations in LVO stroke patients on a MSU were not associated with early clinical changes.

Abstract 162: Arterial Aspirate Derived Exosomes From Patients With Large Vessel Occlusion Are Associated With Increased Blood-brain Barrier Permeability, Decreased Endothelial Integrity As Well Poor Clinical And Radiographic Outcomes Following Mechanical Thrombectomy

Introduction: Exosomes (~30-150nm microvessicles [MVs]), are important mediators of cell-cell communication and have been associated with injurious and neuroprotective processes in experimental stroke models. Since many patients treated with mechanical thrombectomy (MT) do not improve despite successful recanalization we hypothesized that these exosomes may mediate injurious processes leading to worse outcomes. Methods: As part of an IRB approved protocol we analyzed arterial blood and retrieved clots aspirated during MT from patients with anterior circulation LVO. MVs were isolated and their effects on BBB permeability and endothelial monolayer integrity measured by transepithelial/endothelial electrical resistance (TEER) in cultured human endothelial cells were measured. Following adjustment for age, DM, NIHSS this effect was also correlated (Pearson R) with NIHSS, RAPID™ CTP parameters, TICI score, BP post MT, 24hr ASPECTS, ICH incidence and mRS. Results: Forty-eight patients were enrolled; mean age was 71±14yrs, 56% were female and 20% were African-American. Mean NIHSS was 16±6.6 with a median baseline ASPECTS score of 9 (range 3-10). Baseline CTP parameters (N=21) were: infarct core 25.8±38.5cc, mismatch volume 103±72.2cc and hypoperfusion index (Tmax&gt;10s/Tmax&gt;6s) 0.34±0.25. Recanalization (TICI 2b/c/3) was achieved in 93.8%. The median 24hr ASPECTS was 7 (range 0-10). At last follow-up 43.5% of patients achieved a good outcome (mRS&lt;=2). BBB permeability was associated with NIHSS change (r=-0.31, p=0.0093), TICI (r=-0.31, p=0.031), SBP post MT (r=0.41, p=0.0036) and 24hr ASPECTS (r=-0.31, p=0.015). TEER correlated most strongly with NIHSS change (r=0.36, p=0.0041), TICI (r=0.35, p=0.02), 24hr ASPECTS (r=0.37, p=0.027) and hypoperfusion index (r=-0.4, p=0.041). Conclusions: Arterial aspirate derived MVs can be isolated from LVO stroke patients. Their effects on BBB permeability and endothelial integrity significantly correlated with clinical and radiographical markers of poor outcomes. It is therefore plausible that clot derived exosomes may impact neurological outcomes following MT through endothelial and BBB injury. In addition, these in vitro BBB measures may serve as biomarkers for post-stroke outcomes.