90-day mRS Research Articles

Abstract TP143: A Retrospective Study Comparing Clinical Outcomes For Thrombectomy-treated Patients With Large Vessel Occlusion Who Met Or Did Not Meet AHA/ASA Eligibility Criteria

Introduction: In 2015, the AHA/ASA Stroke Guidelines recommended thrombectomy to treat large vessel occlusions (LVOs) based on multiple clinical trials that demonstrated efficacy and safety. Given the strict eligibility criteria employed by these trials, the guidelines recommended thrombectomy for a limited patient population. However, in real-world settings, patients who do not meet eligibility criteria still undergo thrombectomy at the discretion of their treating physician. The purpose of this study is to compare clinical outcomes and complication rates of thrombectomy patients who do not meet the AHA/ASA criteria to those that do. Methods: Data from patients discharged from October 2017 to February 2021 with LKW <= 6 hours were retrospectively abstracted from electronic medical records. Patients under 18 or with posterior circulation stroke were excluded. Patients were grouped by AHA/ASA criteria for thrombectomy treatment into met (M) vs. not-met (NM). The M group criteria were defined as pre-stroke modified Rankin score (mRS) 0-1, occlusion of the internal carotid artery (ICA) or middle cerebral artery (M1), NIH stroke score (NIHSS) of >=6 on arrival, and ASPECTS>=6. All other patients were categorized as NM. Primary outcomes were 90-day mRS, median change from arrival to 90-day mRS, discharge disposition, and treatment complications. Descriptive analyses were performed using Chi-squared test, Fisher’s exact test, or median test, as appropriate. Results: Among 225 patients who met inclusion criteria, 151 (67.1%) M and 74 (32.9%) NM patients were identified. NM patients had worse mRS scores at 90-days (6.0 [4.29, 6.00] vs. 3.0 [0.00, 6.00]) compared to M patients. However, change from pre-stroke to 90-day mRS was not significant between groups (M: 3.0 [1.00, 5.00] vs NM: 3.0 [1.00, 4.00], p<.846.) No differences were found between M or NM for discharge disposition or treatment complications. Conclusions: While patients in the NM group had worse 90-day mRS scores compared to the M group, the change in mRS scores from pre-stroke to 90-day were the same for both. Results support that thrombectomy treatment of LVOs is safe and effective for both groups. Expansion of AHA/ASA guidelines should be considered.

Abstract TP90: Lesion Topography Role On Functional Outcome Of Stroke Patients

Background: The anatomical site of ischemia in stroke patients might impact functional outcome and can be a relevant factor for prognosis and clinical decision. Methods: We included patients from the MR CLEAN stroke trial population who had an adequate 5-9-day control CT scan. The images were segmented and registered over two neuroanatomical atlases. Each anatomical region was classified as affected or spared based on the total amount of voxels in each region interpreted as ischemic on CT imaging. Analysis were conducted with a threshold level of 20% and 50% of the total voxels as a binary classification criteria for considering a brain area as affected by the ischemic core. Univariate and multivariate analysis were conducted to assess for relationships between specific brain regions involvement and worse functional outcome (defined by the 90-day mRS). Results: A total of 356 patients was included. The left dorsal striatum and left insular ribbon were significantly associated with worse outcomes after correction for the total lesion volume (p < 0,05). On a binary logistic model, no areas were significantly associated with worse outcome when a threshold of 20% was used. Both left and right dorsal striatum’s were significantly associated with worse outcome after adjustment for volume when a threshold of 50% was used. Conclusion: Some areas of the brain appear to have a higher impact on clinical outcomes for stroke patients. Areas related to motor function were strongly associated with the 90-day mRS when compared to other brain areas. The impact of a brain region on outcome also seems to depend on which hemisphere has been affected and on the extent to which the region that has ben involved in the ischemia.

Abstract WMP87: Primary Results From The CLEAR Study Of The Safety And Effectiveness Of The Neva Stent Retriever For Large Vessel Thrombectomy

Despite the proven benefit of stent retrievers, challenges to rapid revascularization of large vessel occlusions (LVO) persist. Current stent retrievers have limited effectiveness for removing organized thrombi. The NeVa device is a novel stent retriever designed with openings in the basket cell structure (“drop zones”) intended to capture organized thrombi within the central scaffold during retrieval. Prospective, multicenter, open label, single arm, FDA-regulated IDE study to evaluate the performance of the NeVa device for recanalizing occluded intracranial vessels including ICA, M1/M2 MCA, and vertebrobasilar arteries, within 8 hours of onset. Primary endpoint was rate of eTICI 2b-3 within 3 NeVa passes, tested for non-inferiority against a performance goal of 72% with a margin of -10%. Additional efficacy endpoints included first pass effect to eTICI 2b-3 (FPE) and 90-day mRS 0-2. Primary safety endpoint was 90-day mortality. (ClinicalTrials.gov NCT04514562) (Site-adjudicated revascularization results are reported here. Final core lab results will be presented at the conference.) From April 1, 2021 to April 28, 2022, 139 subjects were enrolled at 25 centers in the US and Europe. Mean age was 67 ± 13 years; 47% were female. Median NIHSS score was 16 (IQR: 12-20). Occlusions were 14 (10%) ICA, 85 (61%) M1, 38 (27%) M2, 1 (1%) Basilar and 1 (1%) PCA. Mean time to first pass was 19 ± 12 minutes. eTICI 2b-3 within 3 NeVa passes occurred in 87.8% (122/139; CI 81.1%,92.7%; non-inferiority p<0.0001; post hoc superiority p=0.002, tested against performance goal of 72%). FPE (to eTICI 2b-3) was observed in 67.6% (94/139), with first pass to eTICI 2b67-3 in 61.2% (85/139) and to eTICI 2c-3 in 43.9% (61/139). Median number of passes was 1 (IQR 1-2). Final eTICI 2b-3 rate was 94.2% (131/139); final eTICI 2c-3 rate was 65.5% (91/139). Good outcome (90-day mRS 0-2) was seen in 62.6% (87/139) and was 74.4% in patients with FPE (70/94 vs. 17/45 (37.8%) without FPE; p<0.0001). Mortality was 9.4% (13/139) with sICH in 8 (5.8%) subjects. The NeVa device is effective and safe for revascularization of LVO strokes and demonstrates high first pass success in this international multicenter study. First pass reperfusion (eTICI 2b-3) was strongly associated with functional independence.

Abstract WP150: Asymptomatic Intracranial Hemorrhage Following Endovascular Treatment Is Not Benign: A Systematic Review And Meta-analysis

Introduction: Asymptomatic intracerebral hemorrhage (aICH) occurs in ~40% of acute ischemic stroke patients after endovascular thrombectomy (EVT). Unlike symptomatic ICH, which is undoubtedly associated with worse outcomes, studies evaluating the association of aICH on long-term outcomes have been inconclusive. We performed a systematic review and meta-analysis to evaluate the long-term effects of post-EVT aICH. Methods: The meta-analysis protocol was submitted to PROSPERO a priori. PubMed, SCOPUS and Web of Science were searched from inception through April 2022 using database-specific searches with combination of keywords and controlled vocabulary. After deduplication, two authors independently reviewed all abstracts. Included studies contained adult AIS patients undergoing EVT with follow-up imaging assessment of ICH reporting comparative outcomes according to aICH vs no ICH . Meta-analysis was performed using Cochrane Review Manager v5.4. Summary effects were estimated by a fixed-effects model to estimate summary odds ratio (OR) of the effect of aICH vs no ICH on primary outcomes of 90-day modified Rankin score 3-6 and mortality. Results: Systematic review yielded 278 studies; 52 abstracts were fully reviewed ; 8 studies fulfilled inclusion criteria (n=4701 patients total; 1562 with aICH). aICH was associated with 90-day mRS 3-6 (OR 2.11 [95% CI 1.85-2.40]; Figure 1A) and higher mortality (OR 1.66 [95% CI 1.41-1.96]; Figure 1B) compared to no ICH. There was insufficient evidence of difference in 90-day mRS 3-6 when studies were grouped according to Heidelberg (n=2 studies; OR 2.37 [95% CI 0.92, 6.12]) vs ECASS (n=5 studies; OR 2.07 [95%CI 1.62, 2.64]) criteria for ICH. Meta-regression analysis adjusting for covariates will be presented Conclusion: aICH is associated with worse 90-day functional outcomes and higher mortality. Further studies to evaluate the factors predicting aICH and treatments aimed at reducing its occurrence are warranted.

Abstract WP117: Effectiveness Of Minimally Invasive Surgery With Thrombolysis For Evacuation Of Intracerebral Hemorrhage: Post Hoc Bayesian Analysis Of A Phase 3 Randomized Controlled Trial

Introduction: Bayesian analyses provide meaningful interpretations of clinical trial data in terms of probabilities of treatment effect. This extends the value of results beyond that obtained from traditional binary cut offs. Such interpretations provide actionable information for conditions with high mortality and no proven treatments, such as intracerebral hemorrhage (ICH). Methods: The minimally invasive surgery with thrombolysis in ICH evacuation (MISTIE 3) trial randomized 506 adults with spontaneous, supratentorial ICH of ≥ 30mL to receive either MISTIE intervention or standard medical care. Using reference priors (minimally informative, enthusiastic, skeptical) and a MISTIE 2-derived prior, we estimated probabilities that the effect of MISTIE intervention exceeds pre-specified thresholds of relative risks (RR) for achieving a 365-day Modified Rankin Scale (mRS) score of 0-3. We also computed the effects of MISTIE intervention on 180 and 30-day mRS and 365, 180 and 30-day mortality. Results: Using a minimally informative prior, the posterior probability of MISTIE intervention having any beneficial effect (RR > 1) on 365-day mRS was 70%. The probabilities of observing RR > 1.02 and > 1.10 were 63% and 34%, respectively. The probabilities of observing RR > 1, 1.02 and 1.10, with other priors are: 87%, 82% and 55% (enthusiastic); 68%, 60% and 30% (skeptical); and 73%, 66% and 38% (MISTIE 2-derived). The probabilities that MISTIE intervention has any beneficial effect on 180 and 30-day mRS, and 365, 180, and 30-day mortality are 65%,80%, 93%, 98% and 99%, respectively. RR, 95% credible intervals across various priors are shown in Figure. Conclusions: The probability that the MISTIE intervention has a favorable functional outcome at 365-days among ICH patients is 68 to 87%. Bayesian-derived probabilities of treatment effect may facilitate shared decision making in ICH management, above and beyond p-value-based frequentist interpretation of trial results.

Abstract WP157: Prognostic Impact Of Pulse Pressure At Admission On Functional Outcomes Post-thrombectomy For Acute Ischemic Stroke

Introduction: Prior studies showed that pulse pressure (PP) correlates with cerebral collateral status, but the prognostic impact of widened PP on thrombectomy outcomes following acute ischemic stroke (AIS) is unclear. We hypothesized that patients with AIS undergoing thrombectomy with a presenting PP of > 60 on admission would be less likely to have successful revascularization and have worse functional outcomes. Methods: Patients treated with a thrombectomy from our institutional retrospective stroke database between 2018 to 2022 were included. Patient demographics and post-thrombectomy outcomes were analyzed using nonparametric t-tests and Chi-Square analysis, with variables <0.20 p-value being included in regression analysis. Results: Of the 134 AIS patients, 60% had a PP > 60. Patients with PP > 60 were older [age 77 (interquartile range (IQR) 68-87) vs 67 (IQR (57-78), p< 0.0001]. There was no difference in the distribution of sex [male 53% vs 52%, p=0.94], M1 occlusion [56% vs 58%, p=0.78], time from last known well to arterial access [306 min (IQR 155-764) vs 242 min (IQR 155-583), p=0.61], NIHSS [17 (IQR 10-23) vs 18 (IQR 11-22), p=0.90], thrombolysis [40% vs 40%, p=0.97], in patients with PP > 60 vs those with a PP ≤ 60 respectively. Discharge mRS was 4 (IQR 4-5) in patients with PP > 60 vs 4 (IQR 4-4) in patients with PP ≤ 60, p=0.02. In this study, 40% lacked a discharge mRS, and no significance was found on 90-day mRS [PP > 60 4 (IQR 2-5) vs 3 (IQR 3-4) PP ≤ 60]. A trend of more patients with PP ≤ 60 having TICI2B/TICI3 was found [75% vs 87%, p=0.06]. In regression analysis, patients with PP > 60 were less likely to have TICI2b/TICI3 after controlling for age [OR 0.23 (95% CI 0.06 - 0.70), p=0.02], but no significant association was found with discharge mRS. Conclusions: The impact of PP on collateral flow in AIS and functional outcome should be studied further in larger AIS cohorts.

Abstract WP129: Sociodemographic, Clinical, And Outcomes Characteristics Of Young Adult Patients With Intracerebral Hemorrhage

Intro: Incidence of intracerebral hemorrhage (ICH) in the young is increasing but risk factors and outcomes are not well characterized. Methods: Using a stroke-specific bioinformatics pipeline across a 7-hospital certified stroke healthcare system, we identified adult non-traumatic ICH cases between 05/16 and 08/22 and flagged young ICH patients (YIP) aged 18 – 45. We compared sociodemographic, comorbidity, clinical, imaging, and treatment characteristics, and outcomes between YIP and non-YIP using logistic regression. Results: Among 1 869 ICH patients, 187 (10%) were YIP. YIP (vs. Non-YIP) were predominantly privately insured (71.1 % vs. 29.8 %), non-Hispanic Black (33.7% vs. 22.2%), Hispanic (26.7% vs. 21.7%), and single (41.2% vs. 20.5%). A higher proportion of YIP were obese and a lower proportion had pre-existing comorbidities (Figure). A lower proportion of YIP were on statins, antiplatelets, or anticoagulants prior to ICH. A significantly smaller proportion of YIP had large hemorrhage volumes (> 30 ml) and experienced lower rates of in-hospital complications such as delirium and SIRS. A significantly greater proportion of YIP underwent craniotomy and had longer lengths of stay. After adjusting for important clinical and sociodemographic correlates of in-hospital mortality, YIP had a 59% lower likelihood of in-hospital mortality or hospice discharge OR (CI): 0.41 (0.20 – 0.82). Additionally, for outcome assessment, YIP were more likely to be contacted [2.9 (1.26, 8.08)], consented [3.7 (1.8, 7.8)], and complete follow-up survey [1.9 (1.0, 3.8)] than non-YIP. Though 50.5% of YIP had a 90-day mRS >3, there was a 51% lower likelihood of severe disability or death in YIP vs. non-YIP. Conclusion: YIP poses a high morbidity burden and understanding long-term functional and cognitive outcomes is important. High follow-up rates provide an opportunity for engaging this often overlooked and underrepresented cohort of critically ill patients in future research.

Quantitative Susceptibility Mapping as a Biomarker to Assess Middle Cerebral Artery Thrombus Composition in Acute Ischemic Stroke

Objective: To compare the quantitative susceptibility mapping (QSM) susceptibility values and pathology composition with different types of thrombi in the middle cerebral artery (MCA), and assess the value of susceptibility weight imaging in thrombus component diagnosis in stroke. Materials and methods: This study included 15 patients (73.47 ± 10.7 years; 6 males and 9 females) who underwent magnetic resonance imaging before mechanical thrombectomy due to acute middle cerebral artery occlusion between January 2017 and December 2019. All patients had the susceptibility vessel sign (SVS) on SWI (susceptibility weighted imaging), and the thrombus susceptibility was measured by signal processing in nuclear magnetic resonance SPIN software. The retrieved thrombi underwent histopathologic analysis, and the correlation between thrombus susceptibility and the pathologic composition was analyzed by two independent Kolmogorov–Smirnov tests. The location and length of thrombi were evaluated on both SWI and DSA, and the correlation was explored using two independent samples Wilcoxon rank test. The correlations between susceptibility and the infarct core volumes (ADC < 620 mm2/s volume map), hypoperfusion volumes (Tmax > 6 s volume map), 90-day modified Rankin scale (mRS), and the National Institutes of Health Stroke Scale (NIHSS) at admission were analyzed by Spearman’s correlation analysis. Results: Among the 15 retrieved thrombi, the mean thrombus susceptibility of RBC-dominant and fibrin-dominant thrombi were 209.88 ± 11.32 and 155.70 ± 28.20 (ppb), respectively (p = 0.037). The average distance of the proximal end of the thrombi to the midline was 24.67 ± 8.43 mm and 24.62 ± 8.44 mm, as measured by SWI and DSA (digital subtraction angiography), respectively (p < 0.001). The correlation between thrombus susceptibility was weakly negatively correlated with ADC < 620 mm2/s volume map (r = 0.356, p = 0.193) and poorly correlated with Tmax > 6 s volume map (r = 0.252, p = 0.365), 90-day mRS (r = 0.182, p = 0.517), and NIHSS at admission (r = 0.262, p = 0.345). Conclusions: The measurements of the Quantitative susceptibility value of thrombi may help predict the composition of thrombi in patients with acute middle cerebral artery occlusion. QSM provides a more accurate method to evaluate the thrombi.

Abstract 10: Determinants Of In-hospital Muscle Loss In Acute Ischemic Stroke - Results Of The Muscle Assessment In Stroke Study (MASS)

Background: Recent literature, primarily based on chronic stroke patients, highlighted a change in the mass and composition of paretic and non-paretic skeletal muscles following stroke. The multi-center, prospective, and observational Muscle Assessment in Stroke Study (MASS; ClinicalTrials.gov ID: NCT03825419) was performed to evaluate the degree of muscle loss during the in-hospital acute stroke setting and determine factors contributing to this loss, especially from the perspective of protein/calorie intake. Methods: Acute dysphagic ischemic stroke patients admitted to neuro-intensive care units were evaluated by computed tomography on days 1 and 14 after admission to determine the cross-sectional muscle area (CSMA) at the level of the mid-humerus, mid-thigh, and third lumbar vertebra. The percentage change in CSMA and variables associated with this change were evaluated by univariate and multivariate analyses. Results: The study population was comprised of 107 patients [median (IQR) age:74 (63-82) years; 58 females]. There were significant reductions in CMSA in all the muscle groups analyzed; the most prominent change was observed in the arms (both: 14.2±10.7%; paretic: 17.7±11.6%; non-paretic: 10.1±12.5%), followed by the muscles in the legs (both: 12.4±8.7%; paretic: 12.9±9.9%; non-paretic: 12.0±9.3%) and L3-vertebra level (5.6±9.8%) (p<0.001 for all). The percent reduction in CSMA of the arms was associated with an unfavorable outcome (90-day mRS≥3) when adjusted for age and admission stroke severity [OR 1.13 (1.04-1.23) for each 1% reduction in CSMA; p=0.003]. The presence of a significant protein (≥0.4 g/kg/d) or calorie (≥5kcal/kg/d) gap between targeted or actual intake was related to a larger decrease in CSMA in all the anatomic regions evaluated (p≤0.05 for all). Other significant predictors of muscle loss included a history of diabetes mellitus, male sex, higher body mass index, in-hospital infections, and the necessity for invasive mechanical ventilation. Conclusions: There is a considerable degree of loss in the global muscle mass in acute ischemic stroke patients over a two-week period. Along several factors, falling significantly behind the daily protein or calorie targets was related to the decrease in muscle area.

Abstract TP106: Outcomes Following Off-label Glyburide In Large Hemispheric Infarction: A Single-center Experience

Background: One in 10 ischemic strokes are large hemispheric infarctions (LHI), half of which cause cerebral edema that can lead to significant mortality. Our center implemented a protocol using acute glyburide in patients with LHI to determine its safety and efficacy in reducing formation of cerebral edema. Methods: Consecutive adult patients at our center (10/2019-08/2021) with LHI who met criteria for the CHARM trial were treated with glyburide per an institutional protocol (2.5mg per nasogastric tube twice daily for 3 days) with multi-disciplinary oversight. Unadjusted logistic regression was used to estimate odds of a favorable shift in 90-day modified Rankin Scale (mRS), with adjustment for age, pre-stroke mRS, National Institutes of Health Stroke Scale (NIHSS) and large vessel occlusion (LVO). Propensity-score matching was used to model shift in 90-day mRS. Safety events were also assessed. Results: Of 1684 stroke patients treated at our center, 95 met criteria for CHARM and were included, among whom 21 completed the glyburide protocol (28 attempted) and 67 received standard-of-care (SOC); 34 patients were propensity-matched (nglyburide=17). Compared to SOC (n=67), patients treated with glyburide (n=21) had similar pre-stroke mRS, NIHSS, and LVOs, but were younger (median 61y vs. 67y, p<0.01). Glyburide was not associated with a favorable shift in 90-day mRS in unadjusted (OR 1.40, 95%CI 0.51-3.88) or adjusted regression (OR 0.71, 95%CI 0.17-2.94), or following propensity score matching (OR 1.39, 95%CI 0.32-6.07). There was no significant reduction in midline shift in unadjusted, adjusted, or propensity score-matched models (p>0.05). Two patients required D50 rescue, and 1 did not complete the protocol due to recurrent hypoglycemia. Conclusions: In this single center analysis, glyburide was found to have a low risk of hypoglycemic events. Despite the small sample size, there was no signal of better clinical or imaging outcomes in treated patients.

Abstract WP156: Thrombectomy Alone Versus Bridging Intravenous Alteplase In The US Population: A Pseudo-randomized Controlled Trial

Introduction: Recent randomized controlled trials (RCT) failed to demonstrate non-inferiority of skipping IV tPA in patients with planned endovascular therapy (EVT). None of these studies included patients from the US due to regulatory challenges. Given practice patterns vary relative to Asia and Europe, we sought to address this topic using a validated alternative to RCTs, fuzzy regression discontinuity design (RDD). Methods: From our prospectively maintained multi-center registry we identified patients with LVO AIS treated with EVT with and without IV tPA treatment from 1/2018 - 9/2021. We used the time cutoff for IV tPA as our discontinuity and assumed subjects on either side of the cutoff have markedly different probabilities of receiving the treatment but are similar in other relevant characteristics. The primary outcome was good functional outcome defined as 90-day mRS 0-2 and it was compared between these two populations immediately adjacent to the cutoff using local linear regressions. Results: Among 694 patients with LVO AIS who received EVT, median age was 69 [IQR 59-79], 50%, were female, 44% White, 24% Black, and 14% Hispanic. 51% received IV tPA, with median onset to treatment time of 109 min [IQR 79-160]. We observed a sharp drop (47%) in the probability of tPA around the cutoff time of 4 hours (allowing 30 minutes for in-hospital evaluation), while there were no significant differences in other relevant features at the cutoff, validating the underlying RDD assumptions (Figure A). Overall, 33% of patients achieved good functional outcomes and there were no significant differences around the cutoff time (Figure B). In fuzzy RDD, there was no evidence of an association of receiving tPA with good functional outcome with regression discontinuity of only 1.0% (p=0.98) Conclusion: Our study provides the highest quality US-based evidence supporting the findings of the outside US trials, demonstrating no benefit of skipping IV tPA in patients with planned EVT.

Abstract WP143: Use Of CTP For Evaluation Of EVT Candidates In The Early Time Window (<6 Hours From Lkwt) Does Not Delay EVT T And Use Of CTP Beyond 6 Hours Improves Speed Of EVT

Introduction: Computerized Tomography Perfusion (CTP) improves detection of distal occlusion and aids in patient selection for endovascular therapy (EVT) for acute ischemic stroke (AIS). As EVT continues to evolve, it is important to assess if CTP continues to aid in the evaluation of AIS or if it adds unnecessary time. Here we assess whether the imaging approach used to evaluate EVT patients was associated with improved door to device times or clinical outcomes. Specifically, we assessed whether CTA alone vs CTA/CTP combined had an effect on door to device (DTD) for EVT, discharge disposition and 90-day mRS. Methods: Data from 1357 AIS EVT patients from 17 hospitals was obtained from a multi-state health system’s stroke registry between Jan 1, 2018, to Apr 11, 2022. Multivariable mixed-effect linear and logistic regression models were employed to identify the association of evaluation type with DTD, discharge disposition and mRS, adjusting for age, sex, race, mode of arrival, NIHSS, stroke mechanism, medical history, and TICI score. Multivariable ordinal regression model was used with mRS as ordinal variable. Each clinical outcome was assessed for last known well (LKW) to arrival below 6 hours and between 6 and 24 hours. Results: The median age was 74 years, 729 (47.7%) were male; 958 (70.6%) arrived in less than 6 hours from LKW and 399 (29.4%) in the interval between 6 and 24 hours. CTA and CTP evaluation was used for 829 (61.1%) patients. In the multivariable models, evaluation with both CTA and CTP was significantly associated with a decrease of the DTD when LKW to arrival was > 6 hours (n= 955, regression coefficient -16, 95% CI -27, -3.6, p = .01) and had no effect on DTD inside of 6 hours. No significant association was found between evaluation type and discharge disposition or 90-day mRs after adjustment for covariates. Conclusions: In EVT patients presenting inside of 6 hours, addition of CTP to CTA caused no delay in DTD and in those presenting from 6-24 hours adding CTP shortened DTD by 16 minutes. This may reflect that CTP allows for more confident and expeditious treatment. These results along with no effect of evaluation type on clinical outcome argue that there is no disadvantage to the use of CTP inside of 6 hours and a clear time advantage beyond 6 hours.

Abstract TP142: Intravenous Thrombolysis In Combination With Mechanical Thrombectomy: An Updated Meta-Analysis Of Clinical Trials

Introduction: Mechanical thrombectomy (MT) is the gold standard for large vessel occlusion (LVO) strokes. The current guidelines state that LVO patients who are eligible for intravenous thrombolysis (IVT) and MT should receive both treatments. However, a few trials investigated the benefits and safety of combining MT with IVT. We conducted this meta-analysis to provide collective evidence on the efficacy and safety of IVT+MT, and to estimate the risk of complications of this approach as compared to MT alone. Methods: We performed a comprehensive literature search of 4 databases (PubMed, Scopus, Web of Science, Cochrane CENTRAL). For outcomes with continuous data, the mean difference (MD) between both groups from the baseline to the endpoint, with its standard deviation (SD), were pooled in the DerSimonian-Laird (DL) random-effect model. For studies reporting data in multiple time points, we considered the last endpoint for the primary analysis. For outcomes with dichotomous data, the frequency of events and the total number of patients in each group were pooled as relative risk (RR) between both groups in the DL random-effect model. All statistical analyses were done by RevMan. Results: 7 clinical trials were included in the meta-analysis with a total of 2,317 patients. There were no significant differences between both groups in terms of functional independence (90-day mRS score 0-2: RR 1.03, 95% CI [0.90 to 1.19], P=0.65), successful recanalization (TICI score ≥2b: RR 1.04, 95% CI [0.92 to 1.17], P=0.53), complete recanalization (TICI score 3: RR 1.06, 95% CI [0.86 to 1.30], P=0.60), or mortality (RR 0.94, 95% CI [0.76 to 1.18], P=0.61). Regarding complications, there were no significant differences between both groups in terms of symptomatic intracranial hemorrhage (RR 0.94, 95% CI [0.74 to 1.20], P=0.64), or any intracranial hemorrhage (RR 1.12, 95% CI [0.94 to 1.34], P=0.57). Conclusion: Our results did not favor either IVT+MT or MT alone in terms of clinical outcomes and complications. However, more trials are needed to further compare both approaches and to evaluate the impact of certain factors on this comparison such as MT technique (Stent Retriever versus Aspiration), LVO location, and the used thrombolytic agent (Alteplase versus Tenecteplase).

Abstract WP13: Value Of Stress Hyperglycemia Ratio In Predicting The Prognosis Of Patients With Acute Ischemic Stroke:a Subgroup Analysis Of The Rescue Bt Clinical Trial

Objective: This study aimed to evaluate the correlation between the stress hyperglycemia and clinical outcomes after large vessel occlusion stroke (LVO) at 90 days. Methods: The RESCUE BT trial was a multicenter, randomized, double-blind, placebo-controlled clinical trial, consisting of 948 patients from 55 centers in China. In this subgroup study, 542 consecutive stroke patients with glucose or glycated hemoglobin values were included. Stress hyperglycemia was evaluated both as a tri-categorical variable (≤1.07 vs 1.08-1.29 vs ≥1.30) and a continuous variable. The primary outcome was favorable functional outcome (modified Rankin Scale [mRS] ≤ 2) at 90 days. The secondary outcome contained excellent functional outcome (modified Rankin Scale [mRS] ≤ 1) and safety outcomes such as 90-day mortality and intracranial hemorrhage. Results: 542 patients were included. Compared to patients with the lowest tertiles of stress hyperglycemia, calculated as glucose/GA ratio, the highest tertiles of stress hyperglycemia was obviously associated with a higher rate of poor functional outcome at 90-day (modified Rankin Scale [mRS] score 3-6) after adjusted for potential covariates (adjusted hazard ratio, 0.44; 95% confidence interval, 0.28-0.69, P < 0.001). This result was also consistent in the excellent clinical outcome of 90-day mRS score 2-6 (adjusted hazard ratio, 0.48; 95% confidence interval, 0.29-0.79, P =0.004). Conclusion: In patients with acute ischemic stroke, lower stress hyperglycemia, as measured by glucose/GA ratio, was more likely to have favorable outcome at 90-day. Trial registration Chinese Clinical Trial Registry Identifier: ChiCTR-IOR-17014167, December 27, 2017.

Abstract 24: Primary Results Of The Preset For Occlusive Stroke Treatment (prost) Randomized Clinical Trial

Importance: Clinical trials focusing on new mechanical thrombectomy (MT) technologies have been typically single-arm studies using historical comparison data to determine the safety and efficacy of the novel device. To date, there has not been a contemporaneous prospective, randomized, controlled study comparing standard to newer designed stent-retrievers. Objective: To evaluate the safety and efficacy of the pRESET (phenox Ltd) compared to the Solitaire (Medtronic Corp) thrombectomy devices in the treatment of large vessel occlusion strokes (LVOS). Methods: Multicenter, prospective, randomized, open-label, blinded endpoint, core lab adjudicated, non-inferiority trial that enrolled 340 patients from October 2019 to February 2022 across 19 US & 5 German sites. Patients aged ≥ 18 years with either anterior or posterior circulation LVOS were included up to 8 hours after symptom onset. Patients were randomly assigned in a 1:1 ratio to either pRESET or Solitaire for the first three device passes.The Primary Endpoint was the proportion of patients achieving a modified Rankin Scale score of 0-2, analyzed by intent to treat with a non-inferiority margin of 0.125 based on the lower bound 95% Confidence Interval. The Primary Safety Endpoint was the proportion of subjects with device- or procedure-related symptomatic intracerebral hemorrhage at 24 (-8/+12) hours as per the SITS-MOST criteria. Secondary Outcome Measures included the rates of (1) Successful Revascularization (defined as expanded Thrombolysis in Cerebrovascular Infarction [eTICI] ≥2b50 ≤3 passes of the assigned device; (2) eTICI ≥2c following the first pass of the assigned device; (3) 90-day mortality and (4) Distribution of 90-day mRS across the entire spectrum of disability (ordinal shift). Results: The study database was locked in August 2022. The analysis is ongoing and the final results will be presented at the 2023 International Stroke Conference. Conclusions and Relevance: PROST is the first randomized clinical trial aiming to compare a novel versus an established stent-retriever technology, establishing a new scientific benchmark for stroke device trials. (ClinicalTrials.gov: NCT03994822).

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 28: First Pass Outcomes And Associated Clot Characteristics: Secondary Analysis Of The Excellent Registry

Introduction: EXCELLENT (NCT03685578) is a global prospective, multicenter, real-world registry of mechanical thrombectomy for stroke with the EmboTrap device as first line treatment which includes clot collection and analysis. Aim of the study: To report the rates of clinical outcomes and clot characteristics associated with first pass reperfusion in EXCELLENT. Methods: Per pass angiographic outcomes assessed by an independent core lab were available in 984 subjects Analysis of clot from 538 cases was performed by independent central labs blinded to clinical data. 90-day mRS assessment was blinded to subject data. Results: First pass reperfusion of mTICI 2b-3 (63.2%) and 2c-3 (38.3%) was significantly predictive of mRS 0-2 or ≤pre-stroke (p=0.011 and p=0.016) but not all-cause mortality at 90 days (p=0.080 and p=0.123, respectively). Further, mTICI 2c-3 in one pass was associated with a higher rate of mRS 0-2 or ≤pre-stroke vs. mTICI 2c-3 reperfusion in >1 pass, (55.5% and 45.1%, respectively, p=0.013) and a rate of all-cause mortality at 90 days of 14.6% vs. 19.8% (p=0.097). Full patient characteristics and clinical outcomes are shown in Table 1. Notable clot composition findings included: RBC (%, mean±SD): mTICI 2c-3, 1 pass 47.69±22.25, mTICI 2c-3, >1 pass 43.86±19.05, (p=0.088); fibrin: mTICI 2c-3, 1 pass 23.20±13.80, mTICI 2c-3 >1 pass 25.40 ± 13.52 (p=0.131); von Willebrand factor (VWF): mTICI2c-3, 1 pass 16.09±14.62, mTICI 2c-3, >1 pass 19.42±17.15 (p=0.038). Conclusions: First pass reperfusion in the EXCELLENT registry was associated with better clinical outcomes at 90 days. Clots retrieved with first pass reperfusion had higher RBC and lower fibrin and VWF content compared to those who achieved reperfusion at greater than one pass.

Abstract WP8: A Comprehensive Analysis Of The Effect Of Intravenous Tirofiban In Combination With Endovascular Thrombectomy On Functional Outcomes In Patients With Large Vessel Occlusion Stroke: The RESCUE BT Trial

Background: In the RESCUE BT (Endovascular Treatment With versus Without Tirofiban for Stroke Patients with Large Vessel Occlusion) trial, enrollment in extended time window was based on non-contrast computed tomography. To assess whether tirofiban was safe and effective in the RESCUE BT trial according to advance imaging selection criteria based on current American Heart Association guidelines. Methods: This is a secondary analysis of a multicenter, double-blinded and randomized trial that was conducted at 55 centers in China and involved 950 participants with stroke with large vessel anterior circulation occlusion from October 2018 to October 2021. All randomized patients were screened according to the current guidelines and were followed up for 90 days from stroke onset. The primary outcome was the distribution of the 90-day modified Rankin scale (mRS) scores. Secondary outcomes included the rates of functional independence (mRS 0-2) and favorable outcome (mRS 0-3). Safety outcomes included the incidences of symptomatic intracranial hemorrhage (sICH) within 48 hours and 90-day mortality. Results: A total of 652 patients (319 in tirofiban group and 333 in placebo group) who met the current guidelines were included in this analysis, with median (IQR) age of 68 (58-75) years, 278 (42.6%) were women. The median 90-day mRS score was 3 (IQR, 1-4) in tirofiban group, and 3 (IQR, 1-4) in placebo group. The adjusted common odds ratio (OR) for a lower level of disability with tirofiban than placebo was 1.08 (95% confidence intervals [CI] 0.83-1.42). Incidence of sICH (10.1% vs 6.3%; adjusted OR 1.70 [95%CI 0.95-3.04]) was not different between groups. However, intravenous tirofiban might be associated with lower disability level (adjusted common OR 1.74 [95%CI 1.14-2.65]; P=0.01) in large artery atherosclerosis patients. Conclusions: There was no significant difference in severity of disability at 90 days with intravenous tirofiban compared with placebo among patients with large vessel anterior circulation occlusion undergoing endovascular therapy according to current guidelines. We observed potential benefits of tirofiban in large artery atherosclerosis patients, and further randomized controlled trials are warranted to validate the present results.

Abstract 86: Understanding Patterns Of Missingness In Acute Ischemic Stroke Trials: A Secondary Analysis Of Pooled Patient-level Follow-up Data.

Background: Understanding the magnitude and causes of missing data is crucial to ensuring scientific integrity of clinical trials. Missing data threaten statistical and ecological validity, as results will only generalize to those who remain represented in the sample. Goal: Identify factors associated with loss at follow-up in acute ischemic stroke trials. Methods: We harmonized patient-level data from multiple NIH-funded acute ischemic stroke trials including NINDS IV-tPA, ALIAS part 2, SHINE, FAST-MAG, IMS-III, POINT, and DEFUSE 3, all of which had a 90-day study outcome. The primary outcome was the proportion of missing modified Rankin Scale (mRS) scores at 90 days. We compared patients with and without a 90-day mRS score among a variety of baseline patient characteristics. Results: Among 9580 subjects, 459 (4.8%) were missing their 90-day mRS. Age and race were associated with missingness. Compared to those with complete data, participants with missing data were younger (62 vs 66 years, p<0.001). Non-Hispanic Black participants represented 18.8% of those with complete data, but 25.3% of those with missing data (p=0.001). History of cardiac disease —atrial fibrillation, coronary artery disease, myocardial infarction—and better baseline NIHSS score were associated less missingness (p’s≤.002 and p<.001, respectively). History of stroke/TIA, however, was positively associated with missingness (50.3% vs. 35.4%, p<.001). Conclusion: Bias due to missingness is an important consideration for all clinical trials, including genetic studies. Disparities in the availability of genetic data compounded by missing phenotypic data creates a twofold disadvantage for underrepresented groups. Long term, we need to understand the biomedical and sociological causes of these associations and develop recruitment and retention strategies to ensure the generalizability of trial results.

Abstract 116: Cortical Thickness Estimation From Clinical T1 Weighted Magnetic Resonance Images To Predict Functional Outcomes After Mechanical Thrombectomy

Background: Endovascular treatment (EVT) is the standard of care for acute ischemic stroke caused by large vessel occlusion (LVO). However, successful EVT does not result in functional independence in many patients. This may be due to pre-existing cortical atrophy that might reduce compensatory plasticity and attenuate recovery. Identifying patients who will most benefit from EVT may be possible using baseline cortical thickness measures as a marker of brain health and providing additional prognostic utility for clinical T1-weighted (T1w) MRI. Objective: Estimate hemispheric and regional cortical thickness from clinical T1w-MRI and determine its influence on functional outcomes post successful EVT. Methods: We performed a retrospective analysis of a prospectively maintained Stroke Thrombectomy and Aneurysm Registry (n=602), collected between 2015 - 2021. We selected 213 patients (mean age 67.5 ± 14.6, 49.3% female) who had adequate quality MRI within 14 days of EVT and a record of the modified Rankin scale (mRS) at 90 days post EVT. Clinical T1w images were transformed into high-resolution images using the convolutional neural network SynthSR. Then, FreeSurfer was used to estimate hemispheric and regional mean cortical thickness from the side contralateral to the stroke, to avoid local lesion effects. In addition to hemispheric cortical thickness, we selected the insula, superior frontal gyrus (SFG), and superior temporal gyrus (STG) for the analysis due to their importance in sensorimotor processing, self-awareness, and social cognition respectively which are important during rehabilitation. Results: In an ordinal regression model adjusted for baseline mRS, the cortical thickness of the SFG and the STG was significantly predictive of 90-day mRS (p=0.005 and p=0.003 respectively), while hemispheric and insular cortical thickness were not. After adjusting for confounders and comorbidities, SFG and STG cortical thickness remained significant predictors of 90-day mRS (p<0.001 for both). Conclusions: The correlation between decreased cortical thickness in specific regions and worse functional outcomes elucidates the effects of pre-existing cortical atrophy in key areas of the brain that may be more important than others during recovery.