Search

Background: Elevated blood pressure after endovascular thrombectomy (EVT) has been associated with an increased risk of hemorrhagic transformation and poor functional outcomes. However, the optimal hemodynamic management after EVT remains unknown, and the blood pressure course in the acute phase of ischemic stroke has not been well characterized. This study aimed to identify patient subgroups with distinct blood pressure trajectories after EVT and study their association with radiographic and functional outcomes. Methods: This multicenter retrospective cohort study included consecutive patients with anterior circulation large-vessel occlusion ischemic stroke who underwent EVT. Repeated time-stamped blood pressure data were recorded for the first 72 hours after thrombectomy. Latent variable mixture modeling was used to separate subjects into five groups with distinct postprocedural systolic blood pressure (SBP) trajectories. The primary outcome was functional status, measured on the modified Rankin Scale 90 days after stroke. Secondary outcomes included hemorrhagic transformation, symptomatic intracranial hemorrhage, and death. Results: Two thousand two hundred sixty-eight patients (mean age [±SD] 69±15, mean National Institutes of Health Stroke Scale 15±7) were included in the analysis. Five distinct SBP trajectories were observed: low (18%), moderate (37%), moderate-to-high (20%), high-to-moderate (18%), and high (6%). SBP trajectory group was independently associated with functional outcome at 90 days ( P P =0.0003 and adjusted odds ratio, 2.2 [95% CI, 1.5–3.2], P P =0.04). No significant association was found between trajectory group and hemorrhagic transformation. Conclusions: Patients with acute ischemic stroke demonstrate distinct SBP trajectories during the first 72 hours after EVT that have differing associations with functional outcome. These findings may help identify potential candidates for future blood pressure modulation trials.

Introduction: Few clinical features have been associated with delayed diagnosis of cerebral venous thrombosis with variable impact of delay on patient outcomes. We therefore sought to use the data from a recent, multicenter study ACTION-CVT (Anticoagulation in the Treatment of CVT) to identify factors associated with delayed CVT diagnosis and evaluate the effect of delay on functional outcome. Methods: All ACTION-CVT patients with available data on date of neurological symptom onset and date of CVT diagnosis were included. Delayed diagnosis of CVT was defined as diagnosis occurring in the fourth (final) quartile of days from symptom onset. We also report the proportion of patients who were discharged from hospital or ED within 3 months prior to index CVT admission for any neurological symptom without being diagnosed with CVT. The primary study outcome was an excellent functional outcome at 90 days defined as modified Rankin Scale (mRS) ≤1. Secondary outcome was partial or complete CVT recanalization on last available venous imaging. Chi-squared and Student’s t-tests were used to identify variables associated with delayed diagnosis. Logistic regression was used to identify independent predictors of delayed diagnosis in CVT as well as the association of delay with outcomes. Results: We included 935 CVT patients in our analysis. Median time from symptom onset to diagnosis was 4 days (IQR: 1-10). Delayed CVT diagnosis occurred in 212 (23%) patients (median time to diagnosis >10 days). Out of 212 patients with delayed CVT diagnosis, 64 (30.2%) patients were discharged from hospital/ED in the 3 months prior to their index CVT admission. Headache symptoms were a predictor of delayed diagnosis (OR: 2.36 [1.26-4.42]; p Conclusion: In a large, multicenter cohort we found that CVT patients presenting with headache were at increased risk of delayed diagnosis, however, delayed diagnosis was not associated with adverse outcomes. CVT diagnosis should be considered in patients presenting with a new headache.

Introduction: Observational studies have found an increased risk of hemorrhagic transformation and worse functional outcomes in patients with higher systolic blood pressure variability (BPV). However, the time-varying behavior of BPV after endovascular thrombectomy (EVT) and its effects on functional outcome have not been well characterized. Patients and methods: We analyzed data from an international cohort of patients with large-vessel occlusion stroke who underwent EVT at 11 centers across North America, Europe, and Asia. Repeated time-stamped blood pressure data were recorded for the first 72 h after thrombectomy. Parameters of BPV were calculated in 12-h epochs using five established methodologies. Systolic BPV trajectories were generated using group-based trajectory modeling, which separates heterogeneous longitudinal data into groups with similar patterns. Results: Of the 2041 patients (age 69 ± 14, 51.4% male, NIHSS 15 ± 7, mean number of BP measurements 50 ± 28) included in our analysis, 1293 (63.4%) had a poor 90-day outcome (mRS ⩾ 3) or a poor discharge outcome (mRS ⩾ 3). We identified three distinct SBP trajectories: low (25%), moderate (64%), and high (11%). Compared to patients with low BPV, those in the highest trajectory group had a significantly greater risk of a poor functional outcome after adjusting for relevant confounders (OR 2.2; 95% CI 1.2–3.9; p = 0.008). In addition, patients with poor outcomes had significantly higher systolic BPV during the epochs that define the first 24 h after EVT ( p Discussion and conclusions: Acute ischemic stroke patients demonstrate three unique systolic BPV trajectories that differ in their association with functional outcome. Further research is needed to rapidly identify individuals with high-risk BPV trajectories and to develop treatment strategies for targeting high BPV.

Introduction: Telestroke has expanded access to tPA and thrombectomy for acute ischemic stroke and improved neurologic outcomes. A key step in the evaluation of acute stroke is non-contrast head CT (HCT) and head and neck CT angiogram (CTA). These imaging studies can either be bundled at presentation, or a delayed CTA may be performed after a tPA decision based on HCT alone. Bundled imaging may facilitate faster transfer and treatment times, while delaying tPA. We investigated the effect of bundled imaging on thrombectomy transfer and treatment times in our telestroke network. Methods: We reviewed patients in our telestroke network from 2019-2021. We included patients who had received HCT and CTA at a partner hospital prior to transfer to our comprehensive stroke center (CSC) for thrombectomy. We collected baseline clinical variables, and timing of imaging, transfer and treatment relative to time of initial HCT. Patients were divided into a bundled imaging group (simultaneous HCT and CTA) or a delayed CTA group. Wilcoxon Rank sum test was used to compare between the two groups for HCT to tPA needle time, HCT to CSC arrival time, and HCT to Groin Puncture Time Results: 273 patients were assessed via telestroke in the study period. Of these 93 were included. 43 patients received bundled CTA, and 50 patients received a delayed CTA. 20 patients received tPA in the bundled group vs 25 in the delayed CTA group. Median CSC transfer time was lower with a bundled imaging strategy (110 min vs 160 min; p Conclusions: Bundled HCT and CTA at telestroke sites was associated with significantly faster transfer and groin puncture times for patients with large vessel occlusion. Further, obtaining the CTA prior to a tPA decision did not significantly prolong HCT-to-needle times.

Introduction: Stroke is the fifth leading cause of death in the US and a major cause of disability. Atrial fibrillation (AF) increases the risk of ischemic stroke fivefold. Cardioembolic stroke in patients with AF is associated with high mortality. The association of elevated cardiac troponin with mortality in patients with acute ischemic stroke has been studied previously; however, there is limited data in subgroups of ischemic stroke etiology. We sought to determine the association of troponin elevation at presentation with 90-day all-cause mortality in patients with acute ischemic stroke and AF. Methods: The I nitiation of A nticoagulation after C ardioembolic Stroke (IAC) study is a multicenter cohort drawn from eight US Stroke Centers. We included consecutive patients hospitalized with acute ischemic stroke and AF between 2015-2018, who had an initial baseline cardiac troponin I (bcTnI) obtained at presentation. The primary outcome was all-cause mortality at 90 days from stroke onset. We undertook multivariable logistic regression to determine the association between elevated bcTnl (≥0.1 ng/mL) and 90-day mortality. Results: Of the 2084 patients enrolled in IAC, 1889 patients had 90-day follow-up of which 1461 patients had bcTnI available. 239 of the included patients (16.4%) had an elevated bcTnl, and death within 90-days occurred in 323 patients (22.1%). Elevated bcTnI was associated with 90-day mortality in univariable analysis (49.4% vs 24.9%; OR 1.71, 95% CI 1.17-2.50, p Conclusion: In acute ischemic stroke patients with AF, elevated bcTnI was independently associated with 90-day all-cause mortality.

Background: A small randomized controlled trial suggested that dabigatran may be as effective as warfarin in the treatment of cerebral venous thrombosis (CVT). We aimed to compare direct oral anticoagulants (DOACs) to warfarin in a real-world CVT cohort. Methods: This multicenter international retrospective study (United States, Europe, New Zealand) included consecutive patients with CVT treated with oral anticoagulation from January 2015 to December 2020. We abstracted demographics and CVT risk factors, hypercoagulable labs, baseline imaging data, and clinical and radiological outcomes from medical records. We used adjusted inverse probability of treatment weighted Cox-regression models to compare recurrent cerebral or systemic venous thrombosis, death, and major hemorrhage in patients treated with warfarin versus DOACs. We performed adjusted inverse probability of treatment weighted logistic regression to compare recanalization rates on follow-up imaging across the 2 treatments groups. Results: Among 1025 CVT patients across 27 centers, 845 patients met our inclusion criteria. Mean age was 44.8 years, 64.7% were women; 33.0% received DOAC only, 51.8% received warfarin only, and 15.1% received both treatments at different times. During a median follow-up of 345 (interquartile range, 140–720) days, there were 5.68 recurrent venous thrombosis, 3.77 major hemorrhages, and 1.84 deaths per 100 patient-years. Among 525 patients who met recanalization analysis inclusion criteria, 36.6% had complete, 48.2% had partial, and 15.2% had no recanalization. When compared with warfarin, DOAC treatment was associated with similar risk of recurrent venous thrombosis (aHR, 0.94 [95% CI, 0.51–1.73]; P =0.84), death (aHR, 0.78 [95% CI, 0.22–2.76]; P =0.70), and rate of partial/complete recanalization (aOR, 0.92 [95% CI, 0.48–1.73]; P =0.79), but a lower risk of major hemorrhage (aHR, 0.35 [95% CI, 0.15–0.82]; P =0.02). Conclusions: In patients with CVT, treatment with DOACs was associated with similar clinical and radiographic outcomes and favorable safety profile when compared with warfarin treatment. Our findings need confirmation by large prospective or randomized studies.

Background Intravenous alteplase improves outcome after acute ischemic stroke without a benefit in 90‐day mortality. There are limited data on whether alteplase is associated with reduced mortality in patients with atrial fibrillation (AF)‐related ischemic stroke whose mortality rate is relatively high. We sought to determine the association of alteplase with hemorrhagic transformation and mortality in patients with AF. Methods and Results We retrospectively analyzed consecutive patients with acute ischemic stroke between 2015 and 2018 diagnosed with AF included in the IAC (Initiation of Anticoagulation After Cardioembolic Stroke) study, which pooled data from stroke registries at 8 comprehensive stroke centers across the United States. For our primary analysis, we included patients who did not undergo mechanical thrombectomy (MT), and secondary analyses included patients who underwent MT. We used binary logistic regression to determine whether alteplase use was associated with risk of hemorrhagic transformation and 90‐day mortality. There were 1889 patients (90.6%) who had 90‐day follow‐up data available for analyses and were included; 1367 patients (72.4%) did not receive MT, and 522 patients (27.6%) received MT. In our primary analyses we found that alteplase use was independently associated with an increased risk for hemorrhagic transformation (odds ratio [OR], 2.23; 95% CI, 1.57–3.17) but reduced risk of 90‐day mortality (OR, 0.58; 95% CI, 0.39–0.87). Among patients undergoing MT, alteplase use was not associated with a significant reduction in 90‐day mortality (OR, 0.68; 95% CI, 0.45–1.04). Conclusions Alteplase reduced 90‐day mortality of patients with acute ischemic stroke with AF not undergoing MT. Further study is required to assess the efficacy of alteplase in patients with AF undergoing MT.

Background and Purpose: Mechanical thrombectomy has dramatically increased patient volumes transferred to comprehensive stroke centers (CSCs), resulting in transfer denials for patients who need higher level of care only available at a CSC. We hypothesized that a distributive stroke network (DSN), triaging low severity acute stroke patients to a primary stroke center (PSC) upon initial telestroke consultation, would safely reduce transfer denials, thereby providing additional volume to treat severe strokes at a CSC. Methods: In 2017, a DSN was implemented, in which mild stroke patients were centrally triaged, via telestroke consultation, to a PSC based upon a simple clinical severity algorithm, while higher acuity/severity strokes were triaged to the CSC. In an observational cohort study, data on acute ischemic stroke patients presenting to regional community hospitals were collected pre- versus post-DSN implementation. Safety outcomes and rate of CSC transfer denials were compared pre-DSN versus post-DSN. Results: The pre-DSN cohort (n=150), triaged to the CSC, had a similar rate of symptomatic intracerebral hemorrhage and discharge location compared with the post-DSN cohort (n=150), triaged to the PSC. Time to stroke unit admission was faster post-DSN (2 hours 40 minutes) versus pre-DSN (3 hours 29 minutes; P P =0.02), despite an increase in telestroke consultation volume over the same period (median, 3 calls per day pre-DSN versus 5 calls per day post-DSN; P =0.001). No patients who were triaged to the PSC required subsequent transfer to the CSC. Conclusions: A DSN, triaging mild ischemic stroke patients from community hospitals to a PSC, safely reduced transfer denials to the CSC, allowing greater capacity at the CSC to treat higher acuity stroke patients.

Background and Purpose: Multiple studies have established that intravenous thrombolysis with alteplase improves outcome after acute ischemic stroke. However, assessment of thrombolysis’ efficacy in stroke patients with atrial fibrillation (AF) has yielded mixed results. We sought to determine the association of alteplase with mortality, hemorrhagic transformation (HT), infarct volume, and mortality in patients with AF and acute ischemic stroke. Methods: We retrospectively analyzed consecutive acute ischemic stroke patients with AF included in the Initiation of Anticoagulation after Cardioembolic stroke (IAC) study, which pooled data from 8 comprehensive stroke centers in the United States. 1889 (90.6%) had available 90-day follow up data and were included. For our primary analysis we used a cohort of 1367/1889 (72.4%) patients who did not undergo mechanical thrombectomy (MT). Secondary analyses were repeated in the patients that underwent MT (n=522). Binary logistic regression was used to determine whether alteplase use was independently associated with risk of HT, final infarct volume, and 90-day mortality, respectively, adjusting for potential confounders. Results: In our primary analyses we found that alteplase use was independently associated with an increased risk for HT (adjusted OR 2.14, 95% CI 1.49 - 3.07, p Conclusion: Thrombolysis with intravenous alteplase was associated with reduced 90-day mortality in AF patients with acute ischemic stroke not undergoing MT. Further study is required to assess the safety and efficacy of alteplase in AF patients undergoing MT and those on DOACs.

Background: Emergent treatment with intravenous thrombolysis and mechanical thrombectomy improved outcomes in patients with acute ischemic stroke. We aim to identify differences in acute stroke treatment trends between strokes occurring in the anterior versus posterior circulation. Methods: The IAC (Initiation of Anticoagulation after Cardioembolic stroke) study represents pooled data registry of 8 comprehensive stroke centers across the United States and included patients with cardioembolic stroke in the setting of AFib. In a post hoc analysis, we identified and separated patients into posterior circulation stroke (PCS) and anterior circulation stroke (ACS) groups based on imaging. Patients without infarct locations or those with multi-circulation infarcts were excluded. We compared baseline characteristics, stroke severity and the treatment trends with alteplase (tPA) and mechanical thrombectomy (MT) in PCS vs ACS using Fisher exact test, t-test and non-parametric tests. We then performed multivariable logistic regression adjusted for baseline differences to determine the associations between PCS and tPA or MT. Results: Of the 2084 patients in IAC cohort, 1589 met inclusion criteria for this study, in which 294 (22.7%) had PCS. Mean age was 76.8 years, 29.3% received tPA and 26.9% had MT. When compared to ACS, patients with PCS were more likely to be men (55.4% vs 45.6%, p=0.003), have diabetes (42.8% vs 29.8, p< 0.001) and lower median NIHSS score on admission (4 vs 8, p Conclusion: Posterior circulation strokes are half as likely to receive thrombolytic therapy and almost a third as likely to have thrombectomy, even after adjusting for baseline stroke severity scores. This is possibly due to difficulty in timely identification and diagnostic delays. There is need for better tools incorporating posterior circulation stroke signs and symptoms to allow for early detection and treatment.

Background and purpose: A proportion of patients with ischemic stroke and atrial fibrillation (AF) have an ischemic stroke despite being prescribed anticoagulation therapy. In this study of patients with ischemic stroke in the setting of AF, we aim to determine the association between prior anticoagulant therapy and 90-day recurrent ischemic events and delayed symptomatic intracranial hemorrhage (sICH). Methods: We included consecutive patients with acute ischemic stroke and AF from the Initiation of Anticoagulation after Cardioembolic stroke (IAC) study from 8 comprehensive stroke centers in the United States. We compared recurrent ischemic events and delayed sICH risk using unadjusted and adjusted cox-regression analyses between patients who were prescribed anticoagulation (AC p ) vs. were naïve to anticoagulation therapy prior to the ischemic stroke (AC n ). For ischemic events, we adjusted for CHA 2 DS 2 -Vasc, anticoagulation initiation, and switching anticoagulant (DOAC to Warfarin or Warfarin to DOAC). For delayed sICH, we adjusted for age, sex, NIHSS score, and early hemorrhagic transformation. Results: 2070 patients had home anticoagulation treatment status recorded. When compared to the AC n group, the AC p group were more likely to have higher median (IQR) CHA 2 DS 2 -Vasc score [5 (4-6) vs. 5 (3-6), p = 0.001], lower NIHSS score [8 (3 - 18) vs. 10 (4 - 18), p = 0.015], severe left atrial enlargement (43.5% vs. 34.5%, p < 0.001), and less likely to receive alteplase (14.4% vs. 36.2%, p < 0.001). In the adjusted cox hazard model, AC p was associated with increased risk of 90-day recurrent ischemic events (adjusted HR 1.52 95% CI 1.01 - 2.29, p = 0.047) but not increased risk of 90-day sICH (adjusted HR 1.10 95% CI 0.46 - 2.61, p = 0.838). In a sensitivity analysis, with severe left atrial enlargement added to the model, the association between AC p and recurrent ischemic event risk did not meaningfully change (adjusted HR 1.41 95% CI 0.87 - 2.28, p = 0.162). Conclusion: Patients with AF and ischemic stroke despite being prescribed anticoagulation therapy are at higher risk of recurrent events. Studies are needed to understand mechanisms of ischemic stroke in these patients to improve stroke prevention strategies.

Background and Purpose: In patients with acute ischemic stroke and atrial fibrillation, treatment with low molecular weight heparin increases early hemorrhagic risk without reducing early recurrence, and there is limited data comparing warfarin to direct oral anticoagulant (DOAC) therapy. We aim to compare the effects of the treatments above on the risk of 90-day recurrent ischemic events and delayed symptomatic intracranial hemorrhage. Methods: We included consecutive patients with acute ischemic stroke and atrial fibrillation from the IAC (Initiation of Anticoagulation after Cardioembolic) stroke study pooling data from stroke registries of 8 comprehensive stroke centers across the United States. We compared recurrent ischemic events and delayed symptomatic intracranial hemorrhage between each of the following groups in separate Cox-regression analyses: (1) DOAC versus warfarin and (2) bridging with heparin/low molecular weight heparin versus no bridging, adjusting for pertinent confounders to test these associations. Results: We identified 1289 patients who met the bridging versus no bridging analysis inclusion criteria and 1251 patients who met the DOAC versus warfarin analysis inclusion criteria. In adjusted Cox-regression models, bridging (versus no bridging) treatment was associated with a high risk of delayed symptomatic intracranial hemorrhage (hazard ratio, 2.74 [95% CI, 1.01–7.42]) but a similar rate of recurrent ischemic events (hazard ratio, 1.23 [95% CI, 0.63–2.40]). Furthermore, DOAC (versus warfarin) treatment was associated with a lower risk of recurrent ischemic events (hazard ratio, 0.51 [95% CI, 0.29–0.87]) but not delayed symptomatic intracranial hemorrhage (hazard ratio, 0.57 [95% CI, 0.22–1.48]). Conclusions: Our study suggests that patients with ischemic stroke and atrial fibrillation would benefit from the initiation of a DOAC without bridging therapy. Due to our study limitations, these findings should be interpreted with caution pending confirmation from large prospective studies.

Background/Aims: Guidelines suggest initiating anticoagulation after cardioembolic stroke within 4-14 days from the index event. Data supporting this suggestion did not account for important factors such as infarct burden or early hemorrhagic transformation. Methods: We pooled data from stroke registries of 8 comprehensive stroke centers across the United States. We included consecutive patients admitted with an acute cardioembolic stroke in the setting of atrial fibrillation. The primary predictor was timing of initiating anticoagulation (0-3 days, 4-14 days, or >14 days) and the primary outcome was the composite endpoint of recurrent stroke/TIA/systemic embolism, symptomatic intracerebral hemorrhage (sICH), or major extracranial hemorrhage (ECH) within 90 days. Results: We enrolled 2090 patients from 8 comprehensive centers in the United States, 1325 met the inclusion criteria (362 were excluded due to non-composite endpoint related death within 90 days, 145 lost to follow up, and 258 were not started on oral anticoagulation or the timing was not reported). Anticoagulation (875 DOAC, 404 Warfarin) was initiated in 0-3 days in 49.7%, 4-14 days in 40.4%, and >14 days in 9.9%. The combined endpoint occurred in 10.7% (142) (98 ischemic events, 21 sICH, and 30 ECH) and did not differ between the three groups: 0-3 days (11.9%), 4-14 days (9.9%), >14 days (9.9%), p=0.525. After adjusting for confounders (such as infarct volume, bridging, CHADS2-Vasc, cardiac thrombus, and hemorrhage on 24-hr imaging), oral anticoagulation timing in the 4-14 day period (vs. >14) was not associated with a reduction in ischemic events (adjusted OR 0.74, p=0.438) and oral anticoagulation timing 4-14 days (vs. 0-3) was not associated with a reduction in sICH (OR 1.28, p=0.638). Factors associated with sICH were bridging (OR 5.36, p=0.001) and hemorrhage on 24-hr imaging (OR 7.26, p Conclusion: In this multicenter real world cohort, the recommended (4-14 days) timeframe to start oral anticoagulation was not associated with reduced ischemic and hemorrhagic outcomes. Randomized trials are required determine the optimal timing of anticoagulation initiation.

Introduction: Endovascular thrombectomy (ET) for treating acute stroke in the real-world has expanded beyond the selection criteria used in major trials, and currently includes posterior circulation strokes. Posterior circulation stroke is believed to have worse outcomes than anterior circulation stroke, and its outcomes following ET are still being studied. We explored the major determinants of functional recovery after ET for posterior circulation stroke in a large cohort of patients from the Stroke Thrombectomy and Aneurysm Registry (STAR). Methods: STAR includes patients undergoing ET for acute ischemic stroke at 12 comprehensive stroke centers in the US and globally. Data on patient demographics, technical and clinical outcomes was reviewed retrospectively from patient charts and procedure notes. Primary outcomes was the modified Ranking Score (mRS) at 90 days dichotomized into favorable (mRS 0-2) and poor outcome (mRS 3-6). Results: A total of 3850 patients were reviewed, of which 345 patients (mean age 60±14) were treated for posterior circulation stroke with predominantly basilar artery occlusion (80%). Patients were treated using aspiration thrombectomy (ADAPT, 39%), stent retriever thrombectomy (31%), combined approach (19%) or intracranial stenting (7%). The overall rate of favorable outcome was 33%. Patients with diabetes, high NIHSS on admission, and proximal occlusions had significantly higher odds of poor functional outcomes on multivariate analysis (p Conclusions: Despite similar rates of functional recovery after ET for anterior circulation stroke between stent retriever and ADAPT, our analysis demonstrates that in posterior circulation stroke, ADAPT may lead to better functional outcomes compared to stent retriever without differences in safety profiles.

Introduction: Hyperacute MRI (hMRI) increases the number of patients eligible for IV tPA in: (1) patients initially suspected to be stroke mimics (SM) and (2) patients with wake-up or unwitnessed stroke onset (WU-UW). Performing hMRI in a time-frame to enable tPA delivery is challenging for many centers; thus, we evaluated which factors were associated with delays in hMRI and hMRI-related tPA treatment at our institution since publication of the WAKE-UP stroke trial in August 2018. Methods: We analyzed 1-year of prospectively collected hMRI data performed between 07.01.2018 to 06.30.2019. We divided the year into three 4-month epochs; the 1 st epoch was before and the 2 nd and 3 rd epochs were after implementing the Wake-up protocol for WU-UW stroke presentations as a new indication to our streamlined hMRI protocol. We compared baseline variables, hMRI indication, hMRI-related tPA utilization, and time metrics for completing hMRI between the 2 nd and 3 rd epochs. We also evaluated discharge outcomes and safety of tPA treatment in this hMRI cohort. Results: Across the 3 epochs, 84 patients underwent hMRI (n=10 vs. 37 vs. 37, respectively), of whom 13 were treated with IV tPA. hMRI-related tPA utilization increased in epochs 2 vs 3 after initiation of the Wake-Up protocol: 8.1% (epoch 2) vs. 21.6% (epoch 3), and number-needed-to-MRI for one tPA treatment dropped from 12.3 to 4.6. In epochs 2 vs. 3, MRI order-to-scan time decreased (28 vs 23 minutes, P=0.039), indicative of process improvement over time. Across all epochs, hMRI indication of WU-UW (vs. SM) was associated with shorter door-to-hMRI completion (68 vs. 83.5 minutes, P=0.041) and shorter door-to-needle time (76 vs. 118 minutes; P=0.030), whereas age, NIHSS, and sex were not associated with hMRI efficiency. None of the 13 patients treated with IV tPA developed symptomatic ICH and 92% were discharged to home or inpatient rehabilitation. Conclusion: In the final epoch, < 5 MRIs were performed for one tPA treatment, suggesting that a hMRI protocol may improve with time and increased utilization, justifying the use of hMRI to increase patient eligibility for IV tPA. WU-UW stroke indications for hMRI may predict shorter hMRI process and faster treatment times.

BACKGROUND AND PURPOSE: Understanding factors associated with ischemic stroke despite therapeutic anticoagulation is an important goal to improve stroke prevention strategies in patients with atrial fibrillation (AF). We aim to determine factors associated with therapeutic or supratherapeutic anticoagulation status at the time of ischemic stroke in patients with AF. METHODS: The Initiation of Anticoagulation after Cardioembolic stroke (IAC) study is a multicenter study pooling data from stroke registries of eight comprehensive stroke centers across the United States. Consecutive patients hospitalized with acute ischemic stroke in the setting of AF were included in the IAC cohort. For this study, we only included patients who reported taking warfarin at the time of the ischemic stroke. Patients not on anticoagulation and patients who reported use of a direct oral anticoagulant were excluded. Analyses were stratified based on therapeutic (INR ≥2) versus subtherapeutic (INR

Introduction: The introduction of thrombectomy into evidence-based stroke care has dramatically increased the volume of stroke patients transferred to comprehensive stroke centers (CSC), often overwhelming their capacity. This has led to increased transfer denials of severe stroke patients who needed thrombectomy. Hypothesis: A “distributive stroke network” (DSN) to triage low severity acute stroke patients to a primary stroke center (PSC) upon initial neurology consultation will be safe, thereby providing additional volume to treat severe strokes at a CSC. Methods: A clinical severity algorithm for external consultations based on NIHSS and time since last known well was created to triage mild acute ischemic stroke patients (both tPA-treated and untreated) to the PSC, while triaging more severe strokes to the CSC. We evaluated clinical outcomes, safety endpoints, stroke consultation volumes, and transfer denials by comparing a stroke cohort after DSN implementation, to a cohort (matched for NIHSS and acuity) admitted to the CSC prior to DSN implementation. Results: The pre-DSN CSC cohort had similar demographics to the post-DSN PSC cohort. Safety outcomes (symptomatic hemorrhage or the need for PSC to CSC transfer) and favorable discharge outcome (home/inpatient rehabilitation vs. nursing home/death) did not differ between pre- and post-DSN cohorts. The post-DSN PSC cohort had a faster time from consult to admission (3 vs. 5 hours) and shorter hospital length of stay (LOS) (2 vs. 3.5 days) compared to the pre-DSN CSC cohort. After DSN implementation, there were fewer CSC stroke transfer denials. Total consultation rates increased over the same period. Conclusion: Triaging external patients to a PSC or CSC during initial consultation (distributive stroke network) based on stroke severity and acuity significantly reduced transfer denials to the CSC. In addition, this DSN algorithm was safe, led to faster admission, and a shorter LOS.

Introduction: Current AHA/ASA guidelines recommend keeping blood pressure (BP) Methods: This was a multicenter international retrospective study that included 7 comprehensive stroke centers. Inclusion criteria were anterior circulation large vessel occlusion (LVO) that was treated with MT, and successful recanalization at the conclusion of the procedure. Patients were divided into three groups based on systolic BP (SBP) goals in the first 24 hours post MT. Group 1) included patients with SBP goal ≤140 mm Hg or ≤120 mm Hg; group 2 included patients with SBP goal ≤160 mm Hg; group 3) included patients with SBP goal ≤220 mm Hg or ≤180 mm Hg. Successful recanalization was defined as TICI 2b-3. Outcome measures included symptomatic intracerebral hemorrhage (sICH), 90-day modified Rankin Scale (mRS), and 90-day mortality. Results: A total of 985 patients were included in the study. More patients in group 3 were white and had Afib than groups 1-2. Likewise, more patients in group 3 received IV tPA. Complete recanalization (TICI 2c-3) was achieved in 88.2%, 53.6%, and 73.2% in groups 1,2,3 respectively (p Conclusion: Blood pressure goals ≤140 and ≤160 were associated with favorable functional outcome.

Introduction: Hypertension is a known predictor of poor outcome and hemorrhagic complications after ischemic stroke. However, the effect of blood pressure (BP) on outcome of those undergoing mechanical thrombectomy and especially after successful recanalization is not well understood. In this study, we investigated the association between BP parameters and outcome measures after successful recanalization with MT. Methods: This was a retrospective, multicenter study, involving 7 comprehensive stroke centers, of patients with acute ischemic stroke due to large vessel occlusion who achieved successful recanalization with MT. Systolic BP (SBP), diastolic BP (DBP) and mean arterial pressure (MAP) were obtained at frequent intervals (at least hourly) for each patient in the first 24 hours following MT. Outcome measures included 90 day-modified Rankin Scale (mRS), 90-day morality, and symptomatic intracerebral hemorrhage (sICH). Successful recanalization was defined as TICI 2b-3, and sICH as any hemorrhage associated with > 4 points increase in NIHSS. A mixed logistic model was used to identify predictors of functional and hemorrhagic outcomes. Results: A total of 989 patients were included, of whom 453 (45.8%) achieved good outcome, defined as an mRS of 0-2. Mean, and maximum SBP were higher in the poor outcome group (131.6 +15 vs. 127 +14.3; p Conclusion: Higher blood pressure was associated with hemorrhagic complications, and worse functional outcome following successful mechanical thrombectomy.

Introduction: blood pressure variability (BPV) in the acute phase following ischemic stroke is associated with worse outcomes, especially in patients with large vessel occlusions. However, the relationship between BPV and outcome after successful recanalization is not well documented. Objective: The aim of this study was to evaluate the association between BPV and outcome after successful recanalization. Methods: This was a retrospective multicenter study of patients with anterior circulation large vessel occlusions who achieved successful recanalization with MT. Successful recanalization was defined as TICI≥2b. BP was recorded in hourly intervals for 24 hours post MT. BPV was defined as the difference between maximum and minimum blood pressure within 24 hours. BPV was calculated for mean arterial pressure (MAP), systolic BP (SBP), and diastolic BP (DBP). Outcome measures included 90 days mRS, symptomatic ICH (sICH), and mortality. sICH was defined based on ECASS criteria. Good outcome was defined as mRS 0-2. Results: A total of 985 patients were included. SBP and MAP variability were higher in poor outcome group (65.2±26 vs. 57± 24.6; p Conclusion: Higher blood pressure variability was associated with worse functional outcomes, higher likelihood of symptomatic hemorrhage, and increased mortality.

Introduction: The management of cerebral venous sinus thrombosis (CVST) is a common problem facing vascular neurologists. AHA/ASA guidelines suggest the use of heparin followed by vitamin K antagonists (VKA) for anticoagulation in CVST. In recent years, the evidence base has solidified for the use of novel oral anticoagulants (NOACs) in lower extremity DVT. Since data supporting their use in CVST is very limited, we sought to review our experience with NOACs in the treatment of CVST at a tertiary care center to address efficacy and safety. Methods: We retrospectively reviewed charts of all patients with CVST treated at our facility with a NOAC between 2014-2018. We collected data on demographics, risk factors for CVST, clinical features at presentation, imaging results, anticoagulation regimen, bleeding complications, and disability at follow up. We compared disability at follow up and major hemorrhagic events with historical controls. Results: We identified 27 patients with CVST treated with a NOAC, 22 of whom had follow up within our system. NOACs included apixaban (68.2%), rivaroxaban (27.3%) and dabigatran (4.5%). NOAC use was associated with stabilization of clot or partial recanalization in 81.8% of patients, and complete recanalization in 18.2%, at a median follow up of 5.5 months. Median mRS at follow up was 0, with one death. Four patients had bleeding complications, including two with symptomatic worsening of ICH. Comparison to historical controls showed no significant differences in terms of disability, death or major hemorrhagic events. Conclusion: Safety and efficacy of NOAC use for CVST were similar to historical controls anticoagulated with other agents. Analyses comparing NOAC-treated patients to 40 contemporary controls treated with vitamin K antagonists at our institution are underway, and prospective assessment of NOAC efficacy and safety in CVST in randomized controlled trials is warranted.

Invading neutrophils are important contributors to brain injury in the context of ischaemia. In vitro evidence suggests a key role for platelet-derived interleukin-1α in mediating neutrophil migration across the vascular endothelium. The aim of this study was to determine the role of platelets and IL-1 using in vivo models of vascular inflammation. Two murine models were used. Bacterial endotoxin, lipopolysaccharide (LPS), was injected intraperitoneally into C57BL/6 mice and lavage of the peritoneal cavity was performed 6 h later. LPS was stereotactically injected into the striatum, and the brain fixed and removed 24 h later. Flow cytometry was used to assess neutrophil levels in suspension, while immunohistochemistry was used to assess neutrophil numbers in tissue. To determine the role of platelets, platelet depletion was induced by injection of anti-CD41 antibody 24 h prior to LPS. To determine the role of IL-1, IL-1α/β double knockout mice were used. In the peritoneum, platelet depletion abolished neutrophil migration, indicating a key role for platelets in this process. A robust inflammatory response was seen in serum cytokines after LPS injection and platelet depletion selectively abrogated the increase in serum IL-1α. IL-1α/β double knockout mice revealed a significant difference in LPS-induced neutrophil migration between knockout animals and controls in the encephalitis model, with no difference in the peritonitis model. In an in vivo peritonitis model, neutrophil migration appears to be dependent on platelets, yet independent of IL-1. In an encephalitis model, neutrophil migration appears dependent on IL-1. This may suggest differential migration mechanisms in different vascular beds.