Emergent Large Vessel Occlusion Patients Research Articles

Postinterventional contrast accumulation early predicts malignant stroke in successfully recanalized patients with emergent large vessel occlusion

Background and objectiveA notable proportion of patients with emergent large vessel occlusion experience malignant middle cerebral infarct (MMI) despite successful recanalization with thrombectomy. In this study, we aim to identify early predictors of MMI in patients successfully recanalized by thrombectomy. MethodsWe retrospectively analyzed atotal of 144 anterior circulation emergent large vessel occlusion patients (90 males and 54 females; mean yr ± SD, 67.7 ± 13.2) who were successfully recanalized by thrombectomy (thrombolysis in cerebral infarction perfusion scale 2b or 3) in the cerebrovascular center of the Soonchunhyang University Bucheon Hospital in South Korea between January 2012 and September 2021. Using pretreatment CT angiography source images (CTA-SIs), collateral status was evaluated, and the Alberta stroke program early CT score (ASPECTS) was determined. Contrast accumulation (CA) was evaluated on non-contrast brain CT scans performed immediately after thrombectomy procedures. Logistic regression and receiver operating characteristic curve analyses were performed using SPSS software, version 26. ResultsNineteen patients (13.2 %, 10 males and 9 females; mean yr ± SD, 67.9 ± 11.3) experienced MMI. The collateral status was poorer (p < 0.001) and the CTA-SI ASPECTS was lower (p < 0.001) in the MMI group than in the non-MMI group. Furthermore, postinterventional CA was more frequent in the MMI group (94.7 % vs 65.6 %, p = 0.010). In particular, distribution of CA was different between the MMI and non-MMI groups. Cortical and subarachnoid CA was more frequent in the MMI group than in the non-MMI group (94.7 % vs 49.6 %, p < 0.001 and 89.5 % vs 20.8 %, p < 0.001). In addition, the ASPECTS for CA, wherein each region was scored 0 if CA existed, were lower in the MMI group (p < 0.001). Multivariate analysis showed that cortical CA, subarachnoid CA, and CA ASPECTS were associated with MMI. A CA ASPECTS ≤ 6 predicted MMI with a sensitivity of 94.7 % and a specificity of 77.6 % (area under the curve, 0.87). ConclusionsOur study shows that the MMI risk in successfully recanalized patients can be predicted by using a simple CT scan immediately after thrombectomy. A cortical or subarachnoid location of CA and lower CA ASPECTS can early predict the future occurrence of MMI.

Predictors of Decompressive Hemicraniectomy in Successfully Recanalized Patients With Anterior Circulation Emergency Large‐Vessel Occlusion

Background Mechanical thrombectomy (MT) has been shown to improve functional outcome in patients with anterior circulation strokes and emergent large‐vessel occlusion (ELVO). Despite successful recanalization, some of these patients require decompressive hemicraniectomy (DHC). We aimed to study the predictors of DHC in successfully recanalized anterior circulation ELVO patients. Methods Consecutive patients with anterior circulation ELVO treated with MT during a 6‐year period were evaluated. Only successfully recanalized patients (modified Thrombolysis in Cerebral Infarction grades 2b, 2c, or 3) after MT were included in the analysis. Baseline demographic, clinical, and procedural variables were compared between patients requiring DHC after successful recanalization versus those who did not. Results Of 453 successfully recanalized patients with ELVO, 47 who underwent DHC had higher admission blood glucose levels (170±88 versus 142±66 mg/dL; P =0.008), lower median Alberta Stroke Program Early CT Scores (9 [interquartile range, 8–10] versus 10 [interquartile range, 9–10]; P =0.002), higher prevalence of poor collaterals on pretreatment computed tomography angiogram (75% versus 26%; P &lt;0.001), and required more passes during MT (median, 3 [interquartile range, 3–4] versus 2 [interquartile range, 1–2]; P =0.001) compared with those who did not undergo DHC. In a multivariable model after adjusting for multiple confounders, higher admission blood glucose levels ( P =0.031), poor collaterals on computed tomography angiography ( P &lt;0.001), and higher number of passes during MT ( P &lt;0.001) emerged as independent predictors of DHC in successfully recanalized patients with ELVO. Conclusions Higher admission blood glucose levels, poor collateral pattern on computed tomography angiography, and higher number of passes during MT were independently associated with DHC in patients with anterior circulation ELVO achieving successful recanalization following MT.

Analysis of Protein Networks Associated with Hemorrhagic Conversion In Emergent Large Vessel Occlusion Patients Undergoing Mechanical Thrombectomy (P5-10.003)

Analysis of Protein Networks Associated with Hemorrhagic Conversion In Emergent Large Vessel Occlusion Patients Undergoing Mechanical Thrombectomy (P5-10.003)

Modeling the Impact of Prehospital Triage on a True-Life Drip and Ship Mechanical Thrombectomy Urban Patient Cohort

Objective: The aim of the study was to model the effect of prehospital triage of emergent large vessel occlusion (ELVO) to endovascular capable center (ECC) on the timing of thrombectomy and intravenous (IV) thrombolysis using real-world data from a multihospital system. Methods: We selected a cohort of 77 consecutive stroke patients who were brought by emergency medical services (EMS) to a nonendovascular capable center and then transferred to an ECC for mechanical thrombectomy (MT) (“actual” drip and ship [DS] cohort). We created a hypothetical scenario (bypass model [BM]), modeling transfer of the patients directly to an ECC, based on patients’ initial EMS pickup address and closest ECC. Using another cohort of 73 consecutive patients, who were brought directly to an ECC by EMS and underwent endovascular intervention, we calculated mean door-to-needle and door-to-arterial puncture (AP) times (“actual” mothership [MS] cohort). Timings in the actual MS cohort and the actual DS cohort were compared to timings from the BM cohort. Results: Median first medical contact (FMC) to IV thrombolysis time was 87.5 min (interquartile range [IQR] = 38) for the DS versus 78.5 min (IQR = 8.96) for the BM cohort, with p = 0.1672. Median FMC to AP was 244 min (IQR = 97) versus 147 min (IQR = 8.96) (p < 0.001), and median FMC to TICI 2B+ time was 299 min (IQR = 108.5) versus 197 min (IQR = 8.96) (p < 0.001) for the DS versus BM cohort, respectively. Conclusions: Modeled EMS prehospital triage of ELVO patients’ results in shorter MT times without a change in thrombolysis times. As triage tools increase in sensitivity and specificity, EMS triage protocols stand to improve patient outcomes.

Modified Prehospital Acute Stroke Severity (mPASS) Scale to Predict Emergent Large Arterial Occlusion.

Introduction To date, identifying emergent large vessel occlusion (ELVO) patients in the prehospital stage is important but still challenging. In this present study, we aimed to design a modified prehospital acute stroke severity (mPASS) scale to identify ELVO patients and compared the scale to the PASS scale which has been published. Methods We retrospectively evaluated a consecutive cohort of acute ischemic stroke (AIS) in our stroke unit who visited the emergercy department. These patients underwent CT angiography (CTA), MR angiography (MRA), or digital subtraction angiography (DSA) at admission. The mPASS scale was calculated based on the National Institutes of Health Stroke Scale (NIHSS) items retrospectively, including the level of consciousness commands, gaze, arm weakness, and aphasia/dysarthria. Receiver operating characteristic (ROC) analysis was used to obtain the area under the curve (AUC) of the mPASS scale, NIHSS, and PASS scale. U-statistics was used to compare the AUC of the mPASS scale to the NIHSS and PASS scale. Results A total of 382 AIS patients were enrolled. The AUC and specificity of the mPASS scale (0.92, 84.4) were all higher than those of the PASS scale. Cortical symptoms such as gaze palsy and consciousness disorder were more specific indicators for ELVO than motor deficits. Conclusions The mPASS scale had a better discrimination for identifying ELVO than the PASS scale in our retrospective cohort. It might predict ELVO in an effective and simple way for paramedics in the prehospital triage stage or emergency stage. Moreover, cortical symptoms might have relatively high specificities to predict ELVO on their own.

POSITIVE: Perfusion imaging selection of ischemic stroke patients for endovascular therapy

BackgroundThe PerfusiOn imaging Selection of Ischemic sTroke patIents for endoVascular thErapy (POSITIVE) trial was designed to evaluate functional outcome in patients with emergent large vessel occlusion (ELVO) presenting within 0–12...

Predictors of mortality for patients with COVID-19 and large vessel occlusion.

BackgroundThis study evaluates the mortality risk of patients with emergent large vessel occlusion (ELVO) and COVID-19 during the pandemic.MethodsWe performed a retrospective cohort study of two cohorts of consecutive patients with ELVO admitted to a quaternary hospital from March 1 to April 17, 2020. We abstracted data from electronic health records on baseline, biomarker profiles, key time points, quality measures and radiographic data.ResultsOf 179 patients admitted with ischemic stroke, 36 had ELVO. Patients with COVID-19 and ELVO had a higher risk of mortality during the pandemic versus patients without COVID-19 (OR 16.63, p = 0.004). An age-based sub-analysis showed in-hospital mortality in 60% of COVID-19 positive patients between 61-70 years-old, 66.7% in between 51-60 years-old, 50% in between 41-50 years-old and 33.3% in between 31-40 years old. Patients that presented with pulmonary symptoms at time of stroke presentation had 71.4% mortality rate. 27.3% of COVID-19 patients presenting with ELVO had a good outcome at discharge (mRS 0-2). Patients with a history of cigarette smoking (p = 0.003), elevated d-dimer (p = 0.007), failure to recanalize (p = 0.007), and elevated ferritin levels (p = 0.006) had an increased risk of mortality.ConclusionPatients with COVID-19 and ELVO had a significantly higher risk for mortality compared to COVID-19 negative patients with ELVO. A small percentage of COVID-19 ELVO patients had good outcomes. Age greater than 60 and pulmonary symptoms at presentation have higher risk for mortality. Other risk factors for mortality were a history of cigarette smoking, elevated, failure to recanalize, elevated d-dimer and ferritin levels.

Emergent Large Vessel Occlusion Stroke During New York City's COVID-19 Outbreak: Clinical Characteristics and Paraclinical Findings.

Background and Purpose:The 2019 novel coronavirus outbreak and its associated disease (coronavirus disease 2019 [COVID-19]) have created a worldwide pandemic. Early data suggest higher rate of ischemic stroke in severe COVID-19 infection. We evaluated whether a relationship exists between emergent large vessel occlusion (ELVO) and the ongoing COVID-19 outbreak.Methods:This is a retrospective, observational case series. Data were collected from all patients who presented with ELVO to the Mount Sinai Health System Hospitals across New York City during the peak 3 weeks of hospitalization and death from COVID-19. Patients’ demographic, comorbid conditions, cardiovascular risk factors, COVID-19 disease status, and clinical presentation were extracted from the electronic medical record. Comparison was made between COVID-19 positive and negative cohorts. The incidence of ELVO stroke was compared with the pre-COVID period.Results:Forty-five consecutive ELVO patients presented during the observation period. Fifty-three percent of patients tested positive for COVID-19. Total patients’ mean (±SD) age was 66 (±17). Patients with COVID-19 were significantly younger than patients without COVID-19, 59±13 versus 74±17 (odds ratio [95% CI], 0.94 [0.81–0.98]; P=0.004). Seventy-five percent of patients with COVID-19 were male compared with 43% of patients without COVID-19 (odds ratio [95% CI], 3.99 [1.12–14.17]; P=0.032). Patients with COVID-19 were less likely to be White (8% versus 38% [odds ratio (95% CI), 0.15 (0.04–0.81); P=0.027]). In comparison to a similar time duration before the COVID-19 outbreak, a 2-fold increase in the total number of ELVO was observed (estimate: 0.78 [95% CI, 0.47–1.08], P≤0.0001).Conclusions:More than half of the ELVO stroke patients during the peak time of the New York City’s COVID-19 outbreak were COVID-19 positive, and those patients with COVID-19 were younger, more likely to be male, and less likely to be White. Our findings also suggest an increase in the incidence of ELVO stroke during the peak of the COVID-19 outbreak.

Abstract TP27: Time-window of Endovascular Therapy for Elvo Patients Will be Extended Beyond 24 Hours After Onset ?

Background and Purpose: Eendovascular thrombectomy(EVT) had a clinical benefit when it was performed within 6 hours after onset symptom in the emergent large vessel occlusion(ELVO) patients. Recently, it is proved that EVT 6 to 24 hours after stroke onset with mismatch between deficit and infarct is benefit. However, it is not unclear whether EVT is effective more than 24 hours after stroke onset. Method: We enrolled ELVO patients treated with EVT more than 24 hours after stroke onset from our prospective registry. We investigated clinical background including onset to puncture time, clinical stroke type, and recanalization rate. We evaluated patient outcome at 3 months after onset and classified patients into two group; good outcome group as modified Rankin Scale (mRS) 0-2 and poor outcome group as mRS 3-6, respectively. We compared clinical background between two groups. Result: In our stroke registry, 443 patients were treated with EVT from January 2011 to July 2019. Among them, 21 patients(5.4%, age was 69(55-72) years old, and male was 16(76%)) were treated with EVT more than 24 hours after stroke onset. All patients had ELVO and clinical and DWI mismatch, which might be thought to be benefit from EVT. Onset to puncture time was median 2632 (1605-6116) minutes and NIHSS scale was 6(2.5-15), and DWI-ASPECTS were 9(7-10). ICA, M1 and BA occlusion were 8(38%), 4 (19%), and 1(4%) patients, respectively. Symptomatic hemorrhage was none. Regarding to patient outcome at 3 months, good and poor outcome were 14(66.7%) and 7(33.3%) patients, respectively. Among the 19 patients with premorbid mRS 0-2, 14(73%) patients achieved good outcome at 3 months. Age, gender, onset to puncture time, DWI-ASPECTS, and ICA occlusion were not different between good and poor outcome groups. However, good outcome patients less frequently had NIHSS score (3.5(2-7) vs. 15(12-23), P=0.006), and cardioembolic stroke (0% vs. 14%, P=0.333). Conclusion: More than a half of ELVO patients with clinical DWI mismatch more than 24 hours after stroke onset had good outcome from EVT. There is possibility that time window of EVT for ELVO patients is extended beyond 24 hours after stroke onset.

Abstract TP303: Improved Metrics and Outcomes Post Implementation of an ELVO Taskforce

Objective: To assess whether the implementation of a standardized protocol for the rapid diagnosis, transfer, and management of emergent large vessel occlusions (ELVO) improves treatment times and reduces disability in patients that undergo mechanical thrombectomy. Methods: Retrospective review was conducted on all patients who underwent thrombectomy within 6 hours of last known well (LKW) from May 22, 2016 to May 1, 2019. Patients with proximal anterior circulation occlusion confirmed on CTA and admission NIHSS of ≥6 were included. Comparisons were made to assess differences in workflow metrics and outcomes pre- and post-ELVO taskforce implementation. 90-day modified Rankin Scale scores (mRS) and patient information was collected from the Houston Methodist Hospital Outcomes Based Prospective Endpoints in Stroke (HOPES) registry. Results: A total of 287 patients met inclusion criteria. 116 were excluded for low NIHSS, out-of-window presentation, undocumented metrics, or lost to follow up. 102 patients presented prior to protocol implementation, with 48 (71.81y [SD±13.51]; 50% M) arriving directly to our CSC and 54 (68.56y [SD±16.85]; 46% M) arriving via inter-facility transfer from a PSC. 69 patients presented post-implementation, 32 (69.78y [SD±16.33]; 53% M) directly and 37 (70.57y [SD±13.96]; 62% M) were transferred. In those presenting directly to the CSC, a statistically significant reduction in the mean door to CT time was observed post-implementation, 12.25 to 5.03 minutes (7.22, 95% CI [1.50, 12.93] p=0.007). In those who were transferred, we found a significant reduction in the mean door-in to door-out time, 138.06 to 128.00 minutes (10.06, 95% CI [7.90, 28.02] p=0.028). A trend towards improved functional outcomes was observed in both cohorts post-protocol implementation. Admission NIHSS, use of lytics, and LKW were found not to be confounders. Conclusion: Based on our review of patients who underwent mechanical thrombectomy, implementation of a standardized protocol for the management of ELVO patients both improved treatment times and showed a trend toward greater functional independence at 90 days. This protocol can be easily replicated to help improve stroke care and potentially reduce disability for patients presenting with ELVO.

Abstract WP287: Modeling the Impact of Pre-Hospital Triage on a True Life Drip and Ship Thrombectomy Patient Cohort

Introduction: Patients with emergent large vessel occlusions (ELVO) are often brought to the closest hospital, possibly given intravenous tPA, and transferred to a hospital capable of performing endovascular intervention. This results in significant delays to thrombectomy and worse patient outcomes when compared with patients brought directly to endovascular centers. In New York City, the pre-hospital system has created a protocol for EMS to use a clinical screening tool to triage stroke patients, and bring those with suspected ELVO directly to comprehensive (CSC) or thrombectomy-capable stroke centers (TSC). Objective: To model the impact of EMS triage protocols on administration of tPA, initiation of endovascular therapy, and recanalization of large vessel occlusions using a real life cohort of thrombectomy patients. Methods: Using our system wide prospectively collected stroke database, we selected a consecutive cohort of 80 thrombectomy patients who were brought by EMS to a primary stroke center then transferred to a TSC or CSC for endovascular intervention. The patient’s initial EMS pickup address was used to calculate the closest TSC or CSC using Google Maps API. Driving time was calculated based on traffic patterns at the time of pickup. Using data from a cohort of 69 consecutive patients that were brought directly to a TSC or CSC by EMS and underwent endovascular intervention, we derived median door to needle and door to groin puncture times. These times, combined with calculated driving distance, were used to model the timing of treatment in the triage model. Timings in the actual cohort versus the model were compared. Results: In the “actual” drip and ship cohort versus our model, first medical contact (FMC) to endovascular center door was 211 versus 32 minutes (p&lt;0.01), first medical contact (FMC) to tPA was 91 versus 81 minutes (p=0.07), FMC to groin puncture was 265 versus 154 minutes (p&lt;0.01), and FMC to TICI2B+ recanalization was 313 versus 205 minutes (p&lt;0.01). Conclusions: Modeled EMS pre-hospital triage of ELVO patients results in a significant decrease in endovascular treatment times without change in tPA times. As triage tools increase in sensitivity and specificity, EMS triage protocols stand to improve patient outcomes.

Endovascular Treatment of Acute Ischemic Stroke.

Endovascular thrombectomy (ET), the standard of treatment for emergent large vessel occlusion (ELVO) strokes, has been subject to rigorous efforts to further improve its usage and delivery for optimised patient outcomes. This review aims to provide an outline and discussion about the recently established and emerging recommendations regarding endovascular treatment of stroke. The indications for ET have expanded continually, with perfusion imaging now enabling selection of patients presenting 6-24h after last-known-well, and improved device and operator proficiency allowing treatment of M2-MCA occlusions and tandem occlusions. Further inclusion of paediatric patients and patients with larger infarct core or milder stroke symptoms for ET has been proposed; however, this remains unproven. This growing applicability is supported by more efficient systems of care, employing modern techniques such as telemedicine, mobile stroke units and helicopter medical services. Ongoing debate exists regarding thrombolytic agent, thrombectomy technique, anaesthesia method and the role of advanced neuroimaging, with upcoming RCTs expected to provide clarification. The journey to further improving the efficacy of ET has advanced and diversified rapidly over recent years, involving improved patient selection, increased utility of advanced neuroimaging and ongoing device redevelopment, within the setting of more efficient, streamlined systems of care. This dynamic and ongoing influx of evidence-based refinements is key to further optimising outcomes for ELVO patients.

Mortality reduction after thrombectomy for acute intracranial large vessel occlusion: meta-analysis of randomized trials

BackgroundThrombectomy for patients with emergent large vessel occlusion (ELVO) is currently recognized as the standard of care for appropriately selected patients. As proven in several randomized clinical trials and meta-analyses,...

Abstract TP19: Impact of Single-Pass Complete Reperfusion on Clinical Outcomes in Emergent Large Vessel Occlusion (ELVO) Patients Treated With Mechanical Thrombectomy (MT)

Introduction: There is mounting evidence indicating that first pass (FP) complete reperfusion (CR) may reduce peri-procedural complications for emergent large vessel occlusion (ELVO) patients treated with mechanical thrombectomy (MT). We investigated the impact of device passes (DP) on the clinical outcomes of ELVO patients who achieved CR following treatment with MT in a high-volume tertiary care stroke center. Methods: Consecutive ELVO patients with CR (modified Thrombolysis in Cerebral Infarction grades IIb/III) at the end of MT were evaluated during a five-year period. Baseline stroke severity was assessed by NIHSS-score. The numbers of DP during the procedure were documented. Standard safety outcomes included symptomatic Intracranial Hemorrhage (sICH) by SITS-MOST criteria and three-month mortality. Standard efficacy outcomes included neurological improvement at 24 hours (determined by the relative reduction in NIHSS-score compared to baseline) and functional improvement at three months [determined as the shift in modified Rankin Scale (mRS) scores]. Results: Among 258 ELVO patients achieving CR during MT the rate of FPCR was 67% (n=173). Patients with FPCR had greater median relative NIHSS-reduction at 24 hours (46% vs. 33%; p=0.033), lower median mRS-scores at three months (2 vs. 3; p=0.034) and lower three-month mortality rates (12% vs. 26%; p=0.005) compared to the rest. The two groups did not differ in sICH rates (5% vs. 10%; p=0.200). FPCR was associated with lower odds of three-month mortality (OR:1.64; 95%:1.03-2.61; p=0.036) on multivariable logistic regression models adjusting for potential confounders (demographics, risk factors, occlusion site, collateral status, stroke severity, onset to groin puncture time, baseline blood pressure and serum glucose values). Conclusions: FPCR appears to impact favourably clinical outcomes in ELVO patients treated with MT. CR following FP results in greater neurological and functional improvement at 24 hours and 3 months respectively.

Abstract TP24: Impact of Pretreatment With Intravenous Thrombolysis on Reperfusion Status in Emergent Large Vessel Occlusion (ELVO) Patients Treated With Mechanical Thrombectomy (MT)

Introduction: It currently remains unclear whether pre-treatment with intravenous thrombolysis (IVT) provides any additional benefits to emergent large vessel occlusion (ELVO) patients undergoing mechanical thrombectomy (MT). We sought to evaluate the impact of pretreatment with IVT on the rate and the speed of complete reperfusion (CR) in LVO patients treated with MT in a high-volume tertiary care stroke center. Methods: Consecutive ELVO patients treated with MT during a five-year period were evaluated. Baseline stroke severity was assessed by NIHSS-score. Standard safety [symptomatic Intracranial Hemorrhage (sICH) by SITS-MOST definition] and efficacy outcomes [CR (modified Thrombolysis in Cerebral Infarction IIb/III), 3-month functional independence (FI; modified Rankin Scale scores of 0-2)] were compared between patients who underwent combined IVT and MT (IVT+MT) vs. direct MT (dMT). The elapsed time between groin puncture to beginning of reperfusion (GPTBRT) and the numbers of device passes (DP) required to achieve CR were also documented. Results: A total of 287 and 132 patients were treated with IVT+MT and dMT respectively. The IVT+MT group had higher CR (74% vs. 63%; p=0.023) and FI (52% vs.38%; p=0.008) rates and shorter median GPTBRT (48 vs. 70 min; p&lt;0.001). The two groups did not differ in sICH rates (7% vs. 9%; p=0.368). Among patients who achieved CR, the median number of required DP was lower in the IVT+MT subgroup (1 vs. 2; p&lt;0.001) and the rate of patients requiring ≤2 DP was higher (98% vs. 77%; p&lt;0.001). IVT+MT was independently related to higher odds of CR (OR:1.64; 95%:1.03-2.61; p=0.036) and shorter GPTBRT (unstandardized linear regression coefficient: -20; 95%CI: -12, -27; p&lt;0.001) on multivariable analyses adjusting for potential confounders including demographics, vascular risk factors, collateral status, stroke severity, location of occlusion and onset to groin puncture time. Among patients with CR, IVT+MT was independently associated with higher likelihood of ≤2 DP (OR:14.75; 95%:4.72-46.04; p&lt;0.001). Conclusions: IVT pretreatment increases the rates of CR and shortens the duration of endovascular procedure by requiring fewer DP in ELVO patients treated with MT.

Abstract WP30: Does Pretreatment With Intravenous Thrombolysis Prevent Infarct in a New Previously Unaffected Territory (INT) in Emergent Large Vessel Occlusion (ELVO) Patients Treated With Mechanical Thrombectomy (MT)?

Introduction: There are contradictory data concerning the preventive role of intravenous thrombolysis (IVT) in preventing infarct in a new previously unaffected territory (INT) in emergent large vessel occlusion (ELVO) patients treated with mechanical thrombectomy (MT). We sought to evaluate the potential association of IVT pretreatment with the likelihood of INT complicating MT in a high-volume tertiary care stroke center. Methods: Consecutive ELVO patients reated with MT during a five-year period were evaluated. Baseline stroke severity was assessed by NIHSS-score. INT was defined using standardized methodology proposed by ESCAPE investigators. Collateral status was graded using ASITN/SIR criteria. The association of INT with 3-month functional independence (FI) defined as modified Rankin Scale scores of 0-2 was also investigated. Results: A total of 419 consecutive ELVO patients received MT [mean age 64±15 years, 50% men, median NIHSS-score 16 points (IQR:11-20), 69% IVT pretreatment). The incidence of INT was lower in patients treated with combination therapy (IVT &amp; MT) than in patients treated with direct MT respectively (10% vs. 20%; p=0.011). INT occurred more frequently in patients with posterior circulation occlusion (28% vs. 10%; p&lt;0.001). Patients with good collaterals tended to have lower rates of INT (11% vs. 18%; p=0.072). The rates of 3-month FI were lower in patients with INT (30% vs. 50%; p=0.007). IVT pretreatment was not independently related to INT (OR: 0.79; 95%CI: 0.34-1.83) on multivariable logistic regression models adjusting for location of occlusion, collateral status and onset to groin puncture time. INT did not emerge as anindependent predictor of 3-month FI (OR: 0.69; 95%CI: 0.29-1.62) on multivariable analyses. Conclusions: IVT pretreatment is not independently associated with lower likelihood of INT in LVO patients treated with MT. INT does not appear to independently affect 3-month functional outcomes.

Abstract TP377: Routing for Rapid Results

Background: In 2016, the American Heart Association (AHA) published recommendations for emergent large vessel occlusion (ELVO) routing at the International Stroke Conference based on symptomatology and distance from a thrombectomy capable stroke center. Research has shown that a rapid door to puncture and reperfusion time leads to improved patient outcomes in large vessel occlusion patients who meet criteria for thrombectomy. The door to puncture (D2P) benchmark for the AHA Get with the Guidelines data registry and the local Emergency Medical Services (EMS) is 90 minutes. Purpose: The purpose of the project was to find a way to shorten the D2P time in ELVO patients in a 265 bed community hospital. Method: The solution to shortening the D2P time was to identify ELVO patients using an evidenced based stroke severity scale. Collaboration ensued between the thrombectomy capable stroke centers and local EMS to discuss ELVO routing. Previously, stroke patients were identified by EMS only using the Cincinnati Prehospital Stroke Scale (CPSS). The local EMS and the participating hospitals selected the Ventura ELVO Scale (VES), an evidenced based stroke severity scale, to assess positive CPSS patients in the field. Policies were developed, education was rolled out, and ELVO routing went live in October 2017 with two ELVO receiving centers. Our hospital, one of the receiving centers, collected data to follow the trend of D2P times. Results: D2P median prior to going live with ELVO routing was 127 minutes. Only one patient out of fifteen patients between December 2016 and August 2017 had a D2P less than 90 minutes. Between October 2017 and July 2018, after ELVO routing began, ten out of fourteen patients had D2P less than 90 minutes. The median improved to 89 minutes on these patients. All D2P times were then tabulated together to calculate a total median time of all cases. Conclusion: ELVO routing combined with the implementation of the VES enabled us to be successful in shortening our D2P to below the benchmark of 90 minutes. This method may be beneficial in other community based hospitals and counties looking to shorten their D2P.

Abstract TMP19: Mobile Stroke Units have Higher Rates of Recanalization of Emergent Large Vessel Occlusion

Introduction: Emergent Large Vessel Occlusion (ELVO) has low recanalization rates with intravenous tissue plasminogen activator (IV tPA). Ultra-early treatment with IV tPA, however, may lead to higher recanalization rates. Mobile stroke units (MSUs) have been shown to reduce treatment times. We compared the recanalization rates of ELVO patients treated on our MSUs against those treated in the traditional emergency department (ED) setting. Methods: We reviewed patients from two MSU programs who were identified to have ELVO treated either in the ED or on the MSU from August 2014 to July 2017. Demographics, imaging characteristics, times to treatment, and recanalization rates were collected and analyzed. Statistical comparison was performed utilizing chi-squared and t-tests. Results: One hundred ninety (34 treated on MSU, 156 treated in the ED) ELVO patients were included in the analysis. Baseline characteristics including age (70 years MSU vs. 66 years in ED); sex (MSU 50% female vs. ED 46.8% female) and vessel occlusion location (ICA: MSU 23.5% vs. ED 25.2%; MCA: MSU 67.6% vs. ED 66.9%) were similar between the two groups. However, the MSU group had a higher initial median National Institutes of Health Stroke Scale (NIHSS) score (15.5 vs. 11.6; p = 0.01). The MSU group also had a shorter time from stroke onset to treatment (70 minutes vs. 126 minutes; p = 0.001). Recanalization of ELVO was seen more frequently on the MSU as compared to in the ED (29.4% vs. 22%; p=0.04). Conclusion: Higher recanalization rate of ELVO was observed with thrombolysis on mobile stroke units as compared to the emergency department.

Abstract WP15: Safety of Dual Antiplatelet Treatment in Emergent Large Vessel Occlusion (ELVO) Patients Treated With Mechanical Thrombectomy (MT) and Extracranial Internal Carotid Artery Stenting

Introduction: Extracranial Internal carotid artery (ExICA) stenting may be required during mechanical thrombectomy (MT) for anterior circulation large vessel occlusions (ACLVO) with coexisting ExICA steno-occlusive disease. We sought to evaluate the safety of acute dual antiplatelet therapy (DAP) in this high-risk MT subgroup. Methods: Consecutive ACLVO patients treated with MT were evaluated during a five-year period. All patients receiving ExICA stenting during MT were also acutely treated with DAP coupled with heparin or eptifibatide drips. Baseline stroke severity and early hypodensity on baseline CT were assessed using NIHSS-score and ASPECTS. Complete reperfusion (CR) was defined as modified Thrombolysis in Cerebral Infarction grades IIb/III) at the end of MT. Final infarct volume (FIV) on brain MRI was assessed at 24-48 hours using standardized methodology. Safety outcomes included symptomatic Intracranial Hemorrhage (sICH) documented by SITS-MOST criteria, infarct in new unaffected territory (INT) determined according to ESCAPE trial methodology and three-month mortality. We also assessed 3-month functional outcomes using modified Rankin Scale (mRS) scores. Results: Among 309 ACLVO patients treated with MT, 24 received additional ExICA stenting. Eptifibatide and heparin drips were administered in 15 (65% of stenting subgroup: 9 patients: aspirin + clopidogrel, 6 patients: aspirin + ticagrelor) and 8 (35% of stenting subgroup: 6 patients: aspirin + clopidogrel, 2 patients: aspirin + ticagrelor) cases respectively. Patients with and without ExICA stenting had similar (p&gt;0.1) median baseline NIHSS-scores (15 vs. 16 points) and ASPECTS (10 vs. 10 points). The two groups did not differ (p&gt;0.1) in terms of median FIV (20 vs. 15 cm 3 ) and median 3-month mRS-scores (2 vs. 2). Patients with ExICA stenting had similar (p&gt;0.1) rates of sICH (5% vs. 8%), INT (0% vs. 9%), CR (74% vs. 70%) and 3-month mRS-scores of 0-2 (55% vs. 51%) compared to the rest. Conclusions: DAP coupled with eptifibatide or heparin drips does not appear to increase peri-procedural complications or to worsen clinical outcome of ELVO patients treated with MT and ExICA stenting.

Abstract WP29: A Propensity-Matched Analysis of Outcomes for Patients With M2 Branch Occlusions at Endovascular Stroke Centers

Introduction: Endovascular therapy (EVT) for Emergent Large Vessel Occlusion (ELVO) is recommended for patients with acute proximal MCA (M1 segment) occlusions (Class I, level A evidence), but the benefits of EVT are uncertain in patients with M2 and more distal occlusions. The purpose of this study was to compare the efficacy and outcomes of EVT-treated M2 ELVOs with EVT-treated M1 ELVOs, and to examine the outcomes of EVT-trerated M2 ELVO patients with those whose M2 ELVOs were not treated. Methods: Data were obtained from a multi-hospital system of patients from January 2014 and May 2018. Two propensity score (PS)-based nearest-neighbor matching analyses were used to match similar patients who had 1) EVT-treated M1 vs EVT-treated M2 ELVOs and 2) EVT-treated vs non-EVT-treated M2 ELVOs. Outcomes included length of stay (LOS), rate of successful reperfusion, discharge disposition, symptomatic intracranial hemorrhage (sICH), and discharge mRS. Chi-squared, Fisher’s exact, and Mann-Whitney U tests were used to compare matched patients. Results: Overall, 160 patients with EVT-treated M2 ELVOs, 350 with EVT-treated M1 ELVOs, and 113 with non-EVT-treated M2 ELVOs were included. Propensity score analyses resulted in 118 matched patients with EVT-treated M2 and EVT-treated M1 occlusions and 70 matched patients with EVT-treated and non-EVT-treated M2 ELVOs. M2 ELVOs made up 20% of all LVO patients. Treated M1 and M2 ELVOs were similar with respect to baseline NIHSS and outcomes. When attempted, intra-arterial reperfusion of M2 ELVOs was achieved at comparable rates to M1 ELVOs with equal rates of sICH (1.7%). Higher NIHSS was associated with EVT of M2 ELVOs (15.00[8.50,21.00] vs 7.00[4.00,17.75]; p&lt;0.001). Rates of mortality trended more favorably in treated M2 ELVOs (12.9% vs 20%), which was not statistically significant (p=0.362). Conclusions: EVT for M2 ELVOs is as safe and effective as EVT for M1 vessel ELVOs. Rates of successful reperfusion, discharge mRS, LOS, sICH, discharge disposition and mortality are similar among EVT treated M2 and EVT treated M1 ELVOs. Though not statistically significant, EVT for patients with M2 ELVOs resulted in favorable trends toward higher survival rates of potential clinical significance.