Clinical relevance of intracranial hemorrhage after thrombectomy versus medical management for large core infarct: a secondary analysis of the SELECT2 randomized trial

BACKGROUND

The incidence of intracerebral hemorrhage (ICH) and its effect on the outcomes after endovascular thrombectomy (EVT) for patients with large core infarcts have not been well-characterized.

METHODS

SELECT2 trial follow-up imaging was evaluated using the Heidelberg Bleeding Classification (HBC) to define hemorrhage grade. The association of ICH with clinical outcomes and treatment effect was examined.

RESULTS

Of 351 included patients, 194 (55%) and 189 (54%) demonstrated intracranial and intracerebral hemorrhage, respectively, with a higher incidence in EVT (134 (75%) and 130 (73%)) versus medical management (MM) (60 (35%) and 59 (34%), both P<0.001). Hemorrhagic infarction type 1 (HBC=1a) and type 2 (HBC=1b) accounted for 93% of all hemorrhages. Parenchymal hematoma (PH) type 1 (HBC=1c) and type 2 (HBC=2) were observed in 1 (0.6%) EVT-treated and 4 (2.2%) MM patients. Symptomatic ICH (sICH) (SITS-MOST definition) was seen in 0.6% EVT patients and 1.2% MM patients. No trend for ICH with core volumes (P=0.10) or Alberta Stroke Program Early CT Score (ASPECTS) (P=0.74) was observed. Among EVT patients, the presence of any ICH did not worsen clinical outcome (modified Rankin Scale (mRS) at 90 days: 4 (3-6) vs 4 (3-6); adjusted generalized OR 1.00, 95% CI 0.68 to 1.47, P>0.99) or modify EVT treatment effect (Pinteraction=0.77).

CONCLUSIONS

ICH was present in 75% of the EVT population, but PH or sICH were infrequent. The presence of any ICH did not worsen functional outcomes or modify EVT treatment effect at 90-day follow-up. The high rate of hemorrhages overall still represents an opportunity for adjunctive therapies in EVT patients with a large ischemic core.

Endovascular Thrombectomy for Large Ischemic Stroke Across Ischemic Injury and Penumbra Profiles

Importance

Whether endovascular thrombectomy (EVT) efficacy for patients with acute ischemic stroke and large cores varies depending on the extent of ischemic injury is uncertain.

Objective

To describe the relationship between imaging estimates of irreversibly injured brain (core) and at-risk regions (mismatch) and clinical outcomes and EVT treatment effect.

Design, Setting, and Participants

An exploratory analysis of the SELECT2 trial, which randomized 352 adults (18-85 years) with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) and large ischemic core to EVT vs medical management (MM), across 31 global centers between October 2019 and September 2022.

Intervention

EVT vs MM.

Main Outcomes and Measures

Primary outcome was functional outcome-90-day mRS score (0, no symptoms, to 6, death) assessed by adjusted generalized OR (aGenOR; values >1 represent more favorable outcomes). Benefit of EVT vs MM was assessed across levels of ischemic injury defined by noncontrast CT using ASPECTS score and by the volume of brain with severely reduced blood flow on CT perfusion or restricted diffusion on MRI.

Results

Among 352 patients randomized, 336 were analyzed (median age, 67 years; 139 [41.4%] female); of these, 168 (50%) were randomized to EVT, and 2 additional crossover MM patients received EVT. In an ordinal analysis of mRS at 90 days, EVT improved functional outcomes compared with MM within ASPECTS categories of 3 (aGenOR, 1.71 [95% CI, 1.04-2.81]), 4 (aGenOR, 2.01 [95% CI, 1.19-3.40]), and 5 (aGenOR, 1.85 [95% CI, 1.22-2.79]). Across strata for CT perfusion/MRI ischemic core volumes, aGenOR for EVT vs MM was 1.63 (95% CI, 1.23-2.16) for volumes ≥70 mL, 1.41 (95% CI, 0.99-2.02) for ≥100 mL, and 1.47 (95% CI, 0.84-2.56) for ≥150 mL. In the EVT group, outcomes worsened as ASPECTS decreased (aGenOR, 0.91 [95% CI, 0.82-1.00] per 1-point decrease) and as CT perfusion/MRI ischemic core volume increased (aGenOR, 0.92 [95% CI, 0.89-0.95] per 10-mL increase). No heterogeneity of EVT treatment effect was observed with or without mismatch, although few patients without mismatch were enrolled.

Conclusion and Relevance

In this exploratory analysis of a randomized clinical trial of patients with extensive ischemic stroke, EVT improved clinical outcomes across a wide spectrum of infarct volumes, although enrollment of patients with minimal penumbra volume was low. In EVT-treated patients, clinical outcomes worsened as presenting ischemic injury estimates increased.

Trial Registration

ClinicalTrials.gov Identifier: NCT03876457.

Endovascular thrombectomy plus medical care versus medical care alone for large ischaemic stroke: 1-year outcomes of the SELECT2 trial

BACKGROUND

Multiple randomised trials have shown efficacy and safety of endovascular thrombectomy in patients with large ischaemic stroke. The aim of this study was to evaluate long-term (ie, at 1 year) evidence of benefit of thrombectomy for these patients.

METHODS

SELECT2 was a phase 3, open-label, international, randomised controlled trial with blinded endpoint assessment, conducted at 31 hospitals in the USA, Canada, Spain, Switzerland, Australia, and New Zealand. Patients aged 18-85 years with ischaemic stroke due to proximal occlusion of the internal carotid artery or of the first segment of the middle cerebral artery, showing large ischaemic core on non-contrast CT (Alberta Stroke Program Early Computed Tomographic Score of 3-5 [range 0-10, with lower values indicating larger infarctions]) or measuring 50 mL or more on CT perfusion and MRI, were randomly assigned, within 24 h of ischaemic stroke onset, to thrombectomy plus medical care or to medical care alone. The primary outcome for this analysis was the ordinal modified Rankin Scale (range 0-6, with higher scores indicating greater disability) at 1-year follow-up in an intention-to-treat population. The trial is registered at ClinicalTrials.gov (NCT03876457) and is completed.

FINDINGS

The trial was terminated early for efficacy at the 90-day follow-up after 352 patients had been randomly assigned (178 to thrombectomy and 174 to medical care only) between Oct 11, 2019, and Sept 9, 2022. Thrombectomy significantly improved the 1-year modified Rankin Scale score distribution versus medical care alone (Wilcoxon-Mann-Whitney probability of superiority 0·59 [95% CI 0·53-0·64]; p=0·0019; generalised odds ratio 1·43 [95% CI 1·14-1·78]). At the 1-year follow-up, 77 (45%) of 170 patients receiving thrombectomy had died, compared with 83 (52%) of 159 patients receiving medical care only (1-year mortality relative risk 0·89 [95% CI 0·71-1·11]).

INTERPRETATION

In patients with ischaemic stroke due to a proximal occlusion and large core, thrombectomy plus medical care provided a significant functional outcome benefit compared with medical care alone at 1-year follow-up.

FUNDING

Stryker Neurovascular.

Endovascular Thrombectomy Treatment Effect in Direct vs Transferred Patients With Large Ischemic Strokes: A Prespecified Analysis of the SELECT2 Trial

Importance

Patients with large ischemic core stroke have poor clinical outcomes and are frequently not considered for interfacility transfer for endovascular thrombectomy (EVT).

Objective

To assess EVT treatment effects in transferred vs directly presenting patients and to evaluate the association between transfer times and neuroimaging changes with EVT clinical outcomes.

Design, Setting, and Participants

This prespecified secondary analysis of the SELECT2 trial, which evaluated EVT vs medical management (MM) in patients with large ischemic stroke, evaluated adults aged 18 to 85 years with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) as well as an Alberta Stroke Program Early CT Score (ASPECTS) of 3 to 5, core of 50 mL or greater on imaging, or both. Patients were enrolled between October 2019 and September 2022 from 31 EVT-capable centers in the US, Canada, Europe, Australia, and New Zealand. Data were analyzed from August 2023 to January 2024.

Interventions

EVT vs MM.

Main Outcomes and Measures

Functional outcome, defined as modified Rankin Scale (mRS) score at 90 days with blinded adjudication.

Results

A total of 958 patients were screened and 606 patients were excluded. Of 352 enrolled patients, 145 (41.2%) were female, and the median (IQR) age was 66.5 (58-75) years. A total of 211 patients (59.9%) were transfers, while 141 (40.1%) presented directly. The median (IQR) transfer time was 178 (136-230) minutes. The median (IQR) ASPECTS decreased from the referring hospital (5 [4-7]) to an EVT-capable center (4 [3-5]). Thrombectomy treatment effect was observed in both directly presenting patients (adjusted generalized odds ratio [OR], 2.01; 95% CI, 1.42-2.86) and transferred patients (adjusted generalized OR, 1.50; 95% CI, 1.11-2.03) without heterogeneity (P for interaction = .14). Treatment effect point estimates favored EVT among 82 transferred patients with a referral hospital ASPECTS of 5 or less (44 received EVT; adjusted generalized OR, 1.52; 95% CI, 0.89-2.58). ASPECTS loss was associated with numerically worse EVT outcomes (adjusted generalized OR per 1-ASPECTS point loss, 0.89; 95% CI, 0.77-1.02). EVT treatment effect estimates were lower in patients with transfer times of 3 hours or more (adjusted generalized OR, 1.15; 95% CI, 0.73-1.80).

Conclusions and Relevance

Both directly presenting and transferred patients with large ischemic stroke in the SELECT2 trial benefited from EVT, including those with low ASPECTS at referring hospitals. However, the association of EVT with better functional outcomes was numerically better in patients presenting directly to EVT-capable centers. Prolonged transfer times and evolution of ischemic change were associated with worse EVT outcomes. These findings emphasize the need for rapid identification of patients suitable for transfer and expedited transport.

Trial Registration

ClinicalTrials.gov Identifier: NCT03876457.

Trial of Endovascular Thrombectomy for Large Ischemic Strokes

BACKGROUND

Trials of the efficacy and safety of endovascular thrombectomy in patients with large ischemic strokes have been carried out in limited populations.

METHODS

We performed a prospective, randomized, open-label, adaptive, international trial involving patients with stroke due to occlusion of the internal carotid artery or the first segment of the middle cerebral artery to assess endovascular thrombectomy within 24 hours after onset. Patients had a large ischemic-core volume, defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower scores indicating larger infarction) or a core volume of at least 50 ml on computed tomography perfusion or diffusion-weighted magnetic resonance imaging. Patients were assigned in a 1:1 ratio to endovascular thrombectomy plus medical care or to medical care alone. The primary outcome was the modified Rankin scale score at 90 days (range, 0 to 6, with higher scores indicating greater disability). Functional independence was a secondary outcome.

RESULTS

The trial was stopped early for efficacy; 178 patients had been assigned to the thrombectomy group and 174 to the medical-care group. The generalized odds ratio for a shift in the distribution of modified Rankin scale scores toward better outcomes in favor of thrombectomy was 1.51 (95% confidence interval [CI], 1.20 to 1.89; P<0.001). A total of 20% of the patients in the thrombectomy group and 7% in the medical-care group had functional independence (relative risk, 2.97; 95% CI, 1.60 to 5.51). Mortality was similar in the two groups. In the thrombectomy group, arterial access-site complications occurred in 5 patients, dissection in 10, cerebral-vessel perforation in 7, and transient vasospasm in 11. Symptomatic intracranial hemorrhage occurred in 1 patient in the thrombectomy group and in 2 in the medical-care group.

CONCLUSIONS

Among patients with large ischemic strokes, endovascular thrombectomy resulted in better functional outcomes than medical care but was associated with vascular complications. Cerebral hemorrhages were infrequent in both groups. (Funded by Stryker Neurovascular; SELECT2 ClinicalTrials.gov number, NCT03876457.).

Abstract TP186: Multidisciplinary Approach To Patent Foramen Ovale (pfo) Closure For Cryptogenic Stroke: Brain-heart Board Experience

Background: The prevalence of PFO is up to 40% in patients with cryptogenic stroke and TIA suggesting paradoxical embolism. PFO closure in carefully selected patients is an effective secondary preventive strategy in these patients. We report predictors of closure recommendation by multidisciplinary board for PFO closure and its impact on outcomes.

Methods: Brain-Heart Board is comprised of vascular neurology, cardiology subspecialities (structural, electrophysiology and cardiac imaging). Adult patients referred to the board for consideration of PFO closure between October 2017 to March 2021 were included in this analysis. Demographics, comorbid conditions, infarct location, Risk of Paradoxical Embolism (RoPE) Score, event frequencies (recurrent TIA or stroke, intracranial hemorrhage (ICH), post-PFO closure cardiac arrythmias) and modified Rankin Scale (mRS at 1 year) were compared between the groups (PFO closure vs. medical management). Multivariable logistic regression was used to identify predictors of closure and chi-square tests to test differences in outcomes for patients according to management.

Results: The board discussed 270 patients (229 stroke; 41 TIA). 119 (44%) patients were recommended for PFO closure of which 117 (98%) had infarct on neuroimaging. Age and RoPE score were similar in closure and medical management cohorts (age; 50±12 vs. 52±13, p>0.05 RoPE 4±3 vs. 6±2 p>0.05). In multivariable analysis, absence of infarct on neuroimaging was an independent predictor of medical management recommendation by the board (OR 0.05 95% CI 0.01-0.19 p<0.05). Event frequency was low in both cohorts (5.9% vs. 4.8% p>0.05) and were comprised primarily of cardiac arrhythmias (6 atrial fibrillation and 1 ICH in Closure group; 1 TIA and 1 recurrent stroke in medical management group). Excellent functional outcome (mRS 0-1) was similar in both cohorts (66% vs. 71% p>0.05) at 1 year.

Conclusion: Multidisciplinary approach for selecting patients for PFO closure results in low frequency of complications (recurrent ischemic stroke, ICH and post-PFO closure cardiac arrythmias) and good outcomes. Presence of infarct on neuroimaging predicts closure recommendation by the multidisciplinary brain-heart board.

Sex differences in endovascular thrombectomy outcomes in large vessel occlusion: a propensity-matched analysis from the SELECT study

BACKGROUND

Sex disparities in acute ischemic stroke outcomes are well reported with IV thrombolysis. Despite several studies, there is still a lack of consensus on whether endovascular thrombectomy (EVT) outcomes differ between men and women.

OBJECTIVE

To compare sex differences in EVT outcomes at 90-day follow-up and assess whether progression in functional status from discharge to 90-day follow-up differs between men and women.

METHODS

From the Selection for Endovascular Treatment in Acute Ischemic Stroke (SELECT) prospective cohort study (2016-2018), adult men and women (≥18 years) with anterior circulation large vessel occlusion (internal carotid artery, middle cerebral artery M1/M2) treated with EVT up to 24 hours from last known well were matched using propensity scores. Discharge and 90-day modified Rankin Scale (mRS) scores were compared between men and women. Furthermore, we evaluated the improvement in mRS scores from discharge to 90 days in men and women using a repeated-measures, mixed-effects regression model.

RESULTS

Of 285 patients, 139 (48.8%) were women. Women were older with median (IQR) age 69 (57-81) years vs 64.5 (56-75), p=0.044, had smaller median perfusion deficits (Tmax >6 s) 109 vs 154 mL (p<0.001), and had better collaterals on CT angiography and CT perfusion but similar ischemic core size (relative cerebral blood flow <30%: 7.6 (0-25.2) vs 11.4 (0-38) mL, p=0.22). In 65 propensity-matched pairs, despite similar discharge functional independence rates (women: 42% vs men: 48%, aOR=0.55, 95% CI 0.18 to 1.69, p=0.30), women exhibited worse 90-day functional independence rates (women: 46% vs men: 60%, aOR=0.41, 95% CI 0.16 to 1.00, p=0.05). The reduction in mRS scores from discharge to 90 days also demonstrated a significantly larger improvement in men (discharge 2.49 and 90 days 1.88, improvement 0.61) than in women (discharge 2.52 and 90 days 2.44, improvement 0.08, p=0.036).

CONCLUSION

In a propensity-matched cohort from the SELECT study, women had similar discharge outcomes as men following EVT, but the improvement from discharge to 90 days was significantly worse in women, suggesting the influence of post-discharge factors. Further exploration of this phenomenon to identify target interventions is warranted.

TRIAL REGISTRATION NUMBER

NCT02446587.

Society of NeuroInterventional Surgery: position statement on pregnancy and parental leave for physicians practicing neurointerventional surgery

Background

The aim of this article is to outline a position statement on pregnancy and parental leave for physicians practicing neurointerventional surgery.

Methods

We performed a structured literature review regarding parental leave policies in neurointerventional surgery and related fields. The recommendations resulted from discussion among the authors, and additional input from the Women in NeuroIntervention Committee, the full Society of NeuroInterventional Surgery (SNIS) Standards and Guidelines Committee, and the SNIS Board of Directors.

Results

Some aspects of workplace safety during pregnancy are regulated by the US Nuclear Regulatory Commission. Other aspects of the workplace and reasonable job accommodations are legally governed by the Family and Medical Leave Act of 1993, the Affordable Care Act of 2010 and the Fair Labor Standards Act of 1938, Americans with Disabilities Act of 1990, Title IX of the Education Amendments of 1972, Title VII of the Civil Rights Act of 1964 as well as rights and protections put forth by the Occupational Safety and Health Administration as part of the United States Department of Labor. Family friendly policies have been associated not only with improved job satisfaction but also with improved parental and infant outcomes. Secondary effects of such accommodations are to increase the number of women within the specialty.

Conclusions

SNIS supports a physician’s ambition to have a family as well as start, develop, and maintain a career in neurointerventional surgery. Legal and regulatory mandates and family friendly workplace policies should be considered when institutions and individual practitioners approach the issue of childbearing in the context of a career in neurointerventional surgery.

Global Impact of COVID-19 on Stroke Care and IV Thrombolysis

OBJECTIVE

To measure the global impact of COVID-19 pandemic on volumes of IV thrombolysis (IVT), IVT transfers, and stroke hospitalizations over 4 months at the height of the pandemic (March 1 to June 30, 2020) compared with 2 control 4-month periods.

METHODS

We conducted a cross-sectional, observational, retrospective study across 6 continents, 70 countries, and 457 stroke centers. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases.

RESULTS

There were 91,373 stroke admissions in the 4 months immediately before compared to 80,894 admissions during the pandemic months, representing an 11.5% (95% confidence interval [CI] -11.7 to -11.3, p < 0.0001) decline. There were 13,334 IVT therapies in the 4 months preceding compared to 11,570 procedures during the pandemic, representing a 13.2% (95% CI -13.8 to -12.7, p < 0.0001) drop. Interfacility IVT transfers decreased from 1,337 to 1,178, or an 11.9% decrease (95% CI -13.7 to -10.3, p = 0.001). Recovery of stroke hospitalization volume (9.5%, 95% CI 9.2-9.8, p < 0.0001) was noted over the 2 later (May, June) vs the 2 earlier (March, April) pandemic months. There was a 1.48% stroke rate across 119,967 COVID-19 hospitalizations. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was noted in 3.3% (1,722/52,026) of all stroke admissions.

CONCLUSIONS

The COVID-19 pandemic was associated with a global decline in the volume of stroke hospitalizations, IVT, and interfacility IVT transfers. Primary stroke centers and centers with higher COVID-19 inpatient volumes experienced steeper declines. Recovery of stroke hospitalization was noted in the later pandemic months.

Abstract P336: Assistance From Automated ASPECTS Software Improves Reader Performance

Purpose: To compare physicians’ ability to read Alberta Stroke Program Early CT Score (ASPECTS) in patients with a large vessel occlusion within 6 hours of symptom onset when assisted by a machine learning-based automatic software tool, RAPID ASPECTS, compared with their unassisted score.

Materials and Methods: 50 baseline CT scans selected from two prior studies (CRISP and GAMES-RP) were read by 3 experienced neuroradiologists who were provided access to a follow-up MRI. The average ASPECT score of these reads was used as the reference standard. Two additional neuroradiologists and 6 non-neuroradiologist readers then read the scans both with and without assistance from the RAPID ASPECTS software and reader improvement was determined. The primary hypothesis was that the agreement between typical readers and the consensus of 3 expert neuroradiologists would be improved with RAPID-assisted vs. unassisted reads. Agreement was based on the percentage of the individual ASPECT regions (50 cases, 10 regions each; N=500) where agreement was achieved.

Results: Typical non-neuroradiologist readers agreed with the expert consensus read in 72% of the 500 ASPECTS regions, evaluated without software assistance. The automated software alone agreed in 77%. When the typical readers read the scan in conjunction with the software, agreement improved to 78% (P<0.0001, test of proportions). RAPID ASPECTS alone achieved correlations for total ASPECT scores that were similar to the expert readers who had access to the follow-up MRI scan to help enhance the quality of their reads.

Conclusion: Typical readers had statistically significant improvement in their scoring of scans when the scan was read in conjunction with the automated RAPID ASPECTS software, achieving agreement rates that were comparable to neuroradiologists.

The Safety and Feasibility of Mechanical Thrombectomy for Mild Acute Ischemic Stroke With Large Vessel Occlusion

BACKGROUND

Prospective evidence to support mechanical thrombectomy (MT) for mild ischemic stroke with large vessel occlusion (LVO) is lacking. There is uncertainty about using an invasive procedure in patients with mild symptoms.

OBJECTIVE

To evaluate the safety and feasibility of MT in patients with mild symptoms and LVO.

METHODS

Our single-arm prospective pilot study recruited patients with LVO and initial National Institute of Health Stroke Scale (NIHSS) &lt;6, who underwent standard MT. Primary safety endpoints were symptomatic intracerebral hemorrhage (sICH), and/or worsening NIHSS by ≥4 points. Secondary endpoints included angiographic recanalization, NIHSS change, final infarct volume, and modified Rankin score (mRS).

RESULTS

We enrolled 20 patients (mean age 65.6 ± 12.3 yr; 45% females). Thrombolysis in Cerebral Ischemia 2B/3 thrombectomy was achieved in 95%. No patients suffered sICH. One patient (5%) had neurologic worsening within 24 h because of underlying intracranial stenosis. No other complications or safety concerns were identified. Median NIHSS was significantly better at discharge (0.5, P = .007) and at last follow-up (0, P &lt; .001) than before treatment (3). Mean post vs preintervention infarct volumes were small without significant difference (1.2 ml, P = .434). Most patients (85%) were discharged directly home. Excellent clinical outcome (mRS 0-1) at last follow-up was seen in 95% of patients.

CONCLUSION

This is one of the first specifically designed prospective studies showing that MT is safe and feasible in patients with low NIHSS and LVO. Chronic underlying vasculopathy may be a challenging dilemma. We observed excellent clinical and radiographic outcomes, but randomized controlled trials are needed to demonstrate the efficacy of MT in this unique cohort.

Early post-Humanitarian Device Exemption experience with the Neuroform Atlas stent

Introduction

The low-profile Neuroform Atlas stent received FDA Humanitarian Device Exemption status (HDE) in January 2018 for stent-assisted coil embolization of wide-necked saccular aneurysms. We review and report our results with the Atlas stent in our institution within the first year after its HDE approval.

Methods

Our retrospective chart review identified patients treated with the Atlas stent. We analyzed the patient demographics, aneurysm characteristics, stent parameters and configuration, complications, angiographic, and clinical outcomes at discharge.

Results

From January to December 2018, 76 Atlas stents were deployed in 58 patients (average 1.3 stents/patient). Median patient age was 63.5 (IQR 56–71) years. Fifty-six (96.6%) patients had elective embolization of unruptured aneurysms, while two (3.4%) patients underwent embolization of a ruptured aneurysm within 2 weeks of subarachnoid hemorrhage. Forty (69.0%) patients were treated with a single stent, 15 (25.9%) with a Y-stent, and three (5.2%) with X-stent configuration. All stent deployments were technically successful. Most stents (82.9%) were the smallest 3 mm diameter devices. Procedural complications included transient stent-associated thrombosis in three (5.2%) patients and aneurysm rupture in one (1.7%). None had distal embolization, associated cerebral infarction, or permanent neurological deficits. Immediate Raymond–Roy 1 occlusion was achieved in 41 (70.7%) patients. Median hospital length of stay for elective aneurysm embolization was 1 day. Excellent outcomes with median National Institute of Health Stroke Scale score 0 (IQR 0–0) and modified Rankin Score 0 (IQR 0–1) were seen for elective patients at discharge.

Conclusion

The Neuroform Atlas stent provided a reliable technical and safety profile for the treatment of intracranial wide-neck aneurysms. Further experience is needed to determine long-term durability and safety of this device.

Time From Imaging to Endovascular Reperfusion Predicts Outcome in Acute Stroke

BACKGROUND AND PURPOSE

This study aims to describe the relationship between computed tomographic (CT) perfusion (CTP)-to-reperfusion time and clinical and radiological outcomes, in a cohort of patients who achieve successful reperfusion for acute ischemic stroke.

METHODS

We included data from the CRISP (Computed Tomographic Perfusion to Predict Response in Ischemic Stroke Project) in which all patients underwent a baseline CTP scan before endovascular therapy. Patients were included if they had a mismatch on their baseline CTP scan and achieved successful endovascular reperfusion. Patients with mismatch were categorized into target mismatch and malignant mismatch profiles, according to the volume of their Tmax >10s lesion volume (target mismatch, <100 mL; malignant mismatch, >100 mL). We investigated the impact of CTP-to-reperfusion times on probability of achieving functional independence (modified Rankin Scale, 0-2) at day 90 and radiographic outcomes at day 5.

RESULTS

Of 156 included patients, 108 (59%) had the target mismatch profile, and 48 (26%) had the malignant mismatch profile. In patients with the target mismatch profile, CTP-to-reperfusion time showed no association with functional independence (P=0.84), whereas in patients with malignant mismatch profile, CTP-to-reperfusion time was strongly associated with lower probability of functional independence (odds ratio, 0.08; P=0.003). Compared with patients with target mismatch, those with the malignant mismatch profile had significantly more infarct growth (90 [49-166] versus 43 [18-81] mL; P=0.006) and larger final infarct volumes (110 [61-155] versus 48 [21-99] mL; P=0.001).

CONCLUSIONS

Compared with target mismatch patients, those with the malignant profile experience faster infarct growth and a steeper decline in the odds of functional independence, with longer delays between baseline imaging and reperfusion. However, this does not exclude the possibility of treatment benefit in patients with a malignant profile.

Thrombectomy for Stroke at 6 to 16 Hours with Selection by Perfusion Imaging

BACKGROUND

Thrombectomy is currently recommended for eligible patients with stroke who are treated within 6 hours after the onset of symptoms.

METHODS

We conducted a multicenter, randomized, open-label trial, with blinded outcome assessment, of thrombectomy in patients 6 to 16 hours after they were last known to be well and who had remaining ischemic brain tissue that was not yet infarcted. Patients with proximal middle-cerebral-artery or internal-carotid-artery occlusion, an initial infarct size of less than 70 ml, and a ratio of the volume of ischemic tissue on perfusion imaging to infarct volume of 1.8 or more were randomly assigned to endovascular therapy (thrombectomy) plus standard medical therapy (endovascular-therapy group) or standard medical therapy alone (medical-therapy group). The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability) at day 90.

RESULTS

The trial was conducted at 38 U.S. centers and terminated early for efficacy after 182 patients had undergone randomization (92 to the endovascular-therapy group and 90 to the medical-therapy group). Endovascular therapy plus medical therapy, as compared with medical therapy alone, was associated with a favorable shift in the distribution of functional outcomes on the modified Rankin scale at 90 days (odds ratio, 2.77; P<0.001) and a higher percentage of patients who were functionally independent, defined as a score on the modified Rankin scale of 0 to 2 (45% vs. 17%, P<0.001). The 90-day mortality rate was 14% in the endovascular-therapy group and 26% in the medical-therapy group (P=0.05), and there was no significant between-group difference in the frequency of symptomatic intracranial hemorrhage (7% and 4%, respectively; P=0.75) or of serious adverse events (43% and 53%, respectively; P=0.18).

CONCLUSIONS

Endovascular thrombectomy for ischemic stroke 6 to 16 hours after a patient was last known to be well plus standard medical therapy resulted in better functional outcomes than standard medical therapy alone among patients with proximal middle-cerebral-artery or internal-carotid-artery occlusion and a region of tissue that was ischemic but not yet infarcted. (Funded by the National Institute of Neurological Disorders and Stroke; DEFUSE 3 ClinicalTrials.gov number, NCT02586415 .).

Abstract 81: Time From Imaging to Endovascular Reperfusion Predicts Outcome in Acute Stroke

Objective: This study aims to describe the relationship between CT perfusion-to-reperfusion time and the probability of functional independence in a cohort of patients undergoing endovascular therapy for acute ischemic stroke.

Methods: We included data from the CT Perfusion to predict Response in Ischemic Stroke Project (CRISP) in which all patients underwent a baseline CT perfusion (CTP) scan prior to endovascular therapy. Patients were included if they had a mismatch on their baseline CT perfusion scan and achieved successful endovascular reperfusion. Patients with mismatch were categorized into ‘target mismatch’ and ‘malignant mismatch’ profiles, according to the volume of their Tmax>10s lesion volume (target mismatch <100 mL; malignant mismatch >100 mL). We investigated the impact of CTP-to-reperfusion times on probability of achieving functional independence (mRS 0-2) at day 90 and radiographic outcomes at day 5.

Results: Of 156 included patients, 108 (59%) had the target mismatch profile, and 48 (26%) had the malignant mismatch profile. In patients with the target mismatch profile, CTP-to-reperfusion time showed no association with functional independence (p=0.84), whereas in patients with malignant mismatch profile, CTP-to-reperfusion time was strongly associated with lower probability of functional independence (OR=0.08, p=0.003). Compared to patients with target mismatch, those with the malignant mismatch profile had significantly more infarct growth (90 [49-166] vs. 43 [18-81] mL, p=0.006) and larger final infarct volumes (110 [61-155 vs. 48 [21-99] mL, p=0.001]).

Conclusion: Patients with the target mismatch and malignant mismatch profile respond differently to time delays between baseline imaging and endovascular reperfusion; those with the malignant profile demonstrate a more rapid decline in favorable clinical outcomes and have greater infarct growth.

Computed tomographic perfusion to Predict Response to Recanalization in ischemic stroke

OBJECTIVE

To assess the utility of computed tomographic (CT) perfusion for selection of patients for endovascular therapy up to 18 hours after symptom onset.

METHODS

We conducted a multicenter cohort study of consecutive acute stroke patients scheduled to undergo endovascular therapy within 90 minutes after a baseline CT perfusion. Patients were classified as "target mismatch" if they had a small ischemic core and a large penumbra on their baseline CT perfusion. Reperfusion was defined as >50% reduction in critical hypoperfusion between the baseline CT perfusion and the 36-hour follow-up magnetic resonance imaging.

RESULTS

Of the 201 patients enrolled, 190 patients with an adequate baseline CT perfusion study who underwent angiography were included (mean age = 66 years, median NIH Stroke Scale [NIHSS] = 16, median time from symptom onset to endovascular therapy = 5.2 hours). Rate of reperfusion was 89%. In patients with target mismatch (n = 131), reperfusion was associated with higher odds of favorable clinical response, defined as an improvement of ≥8 points on the NIHSS (83% vs 44%; p = 0.002, adjusted odds ratio [OR] = 6.6, 95% confidence interval [CI] = 2.1-20.9). This association did not differ between patients treated within 6 hours (OR = 6.4, 95% CI = 1.5-27.8) and those treated > 6 hours after symptom onset (OR = 13.7, 95% CI = 1.4-140).

INTERPRETATION

The robust association between endovascular reperfusion and good outcome among patients with the CT perfusion target mismatch profile treated up to 18 hours after symptom onset supports a randomized trial of endovascular therapy in this patient population. Ann Neurol 2017;81:849-856.

Wake-Up Stroke: Current Understanding

Patients with wake-up strokes account for approximately 1 in 5 individuals presenting with an acute ischemic stroke. However, they are commonly excluded from acute stroke treatment. This article reviews the current understanding of wake-up strokes. A comparison of wake-up and awake-onset strokes demonstrated that they are physiologically, clinically, and radiologically similar. Use of advanced CT and MRI techniques may help extend acute stroke treatment options to patients with wake-up stroke.

A multicenter randomized controlled trial of endovascular therapy following imaging evaluation for ischemic stroke (DEFUSE 3)

Rationale Early reperfusion in patients experiencing acute ischemic stroke is effective in patients with large vessel occlusion. No randomized data are available regarding the safety and efficacy of endovascular therapy beyond 6 h from symptom onset. Aim The aim of the study is to demonstrate that, among patients with large vessel anterior circulation occlusion who have a favorable imaging profile on computed tomography perfusion or magnetic resonance imaging, endovascular therapy with a Food and Drug Administration 510 K-cleared mechanical thrombectomy device reduces the degree of disability three months post stroke. Design The study is a prospective, randomized, multicenter, phase III, adaptive, blinded endpoint, controlled trial. A maximum of 476 patients will be randomized and treated between 6 and 16 h of symptom onset. Procedures Patients undergo imaging with computed tomography perfusion or magnetic resonance diffusion/perfusion, and automated software (RAPID) determines if the Target Mismatch Profile is present. Patients who meet both clinical and imaging selection criteria are randomized 1:1 to endovascular therapy plus medical management or medical management alone. The individual endovascular therapist chooses the specific device (or devices) employed. Study outcomes The primary endpoint is the distribution of scores on the modified Rankin Scale at day 90. The secondary endpoint is the proportion of patients with modified Rankin Scale 0-2 at day 90 (indicating functional independence). Analysis Statistical analysis for the primary endpoint will be conducted using a normal approximation of the Wilcoxon-Mann-Whitney test (the generalized likelihood ratio test).

Hyperleptinemia Is a Risk Factor for the Development of Central Arterial Stiffness in Kidney Transplant Patients

BACKGROUND

Arterial stiffness could cause adverse outcomes in kidney transplant (KT) patients. Leptin has a role in influencing vascular smooth muscle that may contribute to atherosclerosis. The aim of this study was to evaluate the relationship between fasting serum leptin concentration and carotid-femoral pulse wave velocity (cfPWV) in KT patients.

MATERIALS AND METHODS

Fasting blood samples were obtained from 55 KT patients and 65 subjects from the outpatient department were enrolled as the control group. The cfPWV values of >10 m/s were used to define as the high arterial stiffness group and <10 m/s as the low arterial stiffness group. The predictive ability of leptin for arterial stiffness of KT was assessed using receiver operating characteristic (ROC) curve and multivariate logistic regression analyses.

RESULTS

Kidney transplant patients had lower hemoglobin, but higher blood urea nitrogen, creatinine, total cholesterol, diastolic blood pressure, intact parathyroid hormone levels, and leptin levels than controls. Although cfPWV levels were higher in KT patients, there is no difference of cfPWV levels between KT patients and control (P = .595). Fifteen KT patients (27.3%) were defined in the high arterial stiffness group, and serum leptin level was higher in the high arterial stiffness group compared with the low arterial stiffness group in KT patients (P < .001). Multivariate logistic regression analysis showed that leptin (odds ratio: 1.044, 95% confidence interval [CI]: 1.016-1.072, P = .002) was an independent predictor of arterial stiffness in KT patients. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the ROC curve predicting arterial stiffness in KT patients were 73.33%, 87.5%, 68.7%, 89.7%, and 0.828 (95% CI: 0.703-0.917, P < .001), and the leptin cut-off value was 74.14 ng/mL.

CONCLUSION

Serum fasting leptin level could predict the development of central arterial stiffness of KT patients.

Abstract WP34: Associations Between CTP Ischemic Core Volume, ASPECTS Scores and Clinical Outcomes After Endovascular Reperfusion

Introduction: ASPECTS and CT perfusion (CTP) lesion volumes have been used to triage patients with large artery occlusions to endovascular therapy. Specifically, ASPECTS ≤5 and CTP infarct core >50 mL excluded patients from some recent endovascular trials. It is unclear how well these criteria select patients who will have poor functional outcomes despite reperfusion and if the criteria are interchangeable.

Hypothesis: ASPECTS and CTP infarct volumes are correlated and both predict clinical outcome.

Methods: Patients with anterior circulation strokes were enrolled in a prospective multi-center study (CRISP) if CTP could be obtained <90 minutes before endovascular treatment, and intervention performed <18h from onset. Reperfusion was defined as >50% reduction from baseline Tmax>6s volume on early follow-up MRI (<36h from baseline CT) or final TICI 2b/3 if follow-up MRI unavailable. A single blinded reader at the core imaging facility determined ASPECTS on baseline CT. Baseline ischemic core volumes were assessed using automated software (RAPID). Good outcome was defined as mRS 0-2 and poor outcome as mRS 5-6.

Results: This analysis includes 165 patients with reperfusion after endovascular therapy. Baseline ASPECTS and infarct core volume are inversely associated (p=0.009). Lower ASPECTS and larger infarct core were associated with a lower chance of good outcome in univariate analysis: OR for good outcome was 0.8 (95% CI 0.7-1.0) per point decrease in ASPECTS and 0.8 (95% CI 0.6-0.9) per 10mL increase in infarct core. Adjusted for baseline NIHSS and age, core remained a predictor of good outcomes (p=0.025) while ASPECTS showed a strong trend (p=0.072). The PPV for poor outcome despite reperfusion was 38% (5/13) for infarct core >50 mL and 0% (0/7) for ASPECTS ≤5 (p=0.1 for difference in PPV). No patient met both criteria.

Conclusions: The ASPECTS and ischemic core volume criteria used to exclude patients from some endovascular therapy trials, did not agree in identifying patients with presumed poor outcomes. Neither criterion had a high specificity for identifying patients destined to have a poor outcome despite reperfusion. Randomized trials are warranted to assess the efficacy of endovascular therapy in patients with ischemic core lesions >50 ml and ASPECTS ≤5.

Abstract 6: Patient Selection is a Better Predictor of Good Outcome Than Time to Reperfusion in Acute Ischemic Stroke

Introduction: Intra-arterial therapy has become standard-of-care for stroke patients with large vessel occlusions presenting within 6 hours of symptom onset. Treatment effectiveness at later times is currently unknown. Using data from the CT Perfusion (CTP) to predict Response to recanalization in Ischemic Stroke Project (CRISP), we assessed the effect of time to treatment on the probability of good outcomes.

Hypothesis: Symptom onset-to-reperfusion time is not associated with probability of favorable outcomes in patients with target mismatch who achieve reperfusion.

Methods: All patients enrolled underwent baseline CTP. For this analysis, we included data from patients with target mismatch (ratio of Tmax>6s lesion to core volume of >1.8) who achieved endovascular reperfusion. We determined reperfusion status by early follow-up MRI or CTP, or final TICI score 2b-3 if early follow-up perfusion imaging is unavailable. We defined good functional outcome (GFO) as mRS 0-2 at day 90. We assessed the probability of good outcome as a function of onset-to-reperfusion time using logistic regression, with prespecified adjustment for age and baseline NIHSS.

Results: Following intra-arterial intervention performed within 18 hours, 102 patients with target mismatch achieved reperfusion. Median onset-to-reperfusion time was 6.6 hours (IQR 5.2-9.5). In univariate analysis, onset-to-reperfusion time was not associated with GFO (p=0.19), whereas age and NIHSS were. Similarly, in multivariate analysis, age and NIHSS were associated with GFO, while onset-to-reperfusion time was not. The adjusted relative risk per hour of delay is 0.994 (95% CI 0.97-1.02). GFO was achieved in 71.4% of patients treated within 6 hours, and in 61.7% of patients treated after 6 hours.

Conclusion: The lack of significant association between onset-to-reperfusion time and GFO, and the high proportion of patients achieving good outcomes at 6-18 hours, suggest that endovascular interventions may be beneficial beyond 6 hours with a CTP target mismatch profile, supporting randomized controlled trials of endovascular therapy in the extended time window in selected patients.

Abstract 57: Main Results of the CTP to Predict Response to Recanalization in Ischemic Stroke Project (CRISP)

Background: Recent acute stroke trials showed benefit from intra-arterial thrombectomy (IAT) up to 6 hrs. We aimed to assess CT Perfusion (CTP) for selection of patients for endovascular therapy up to 18 hrs.

Hypothesis: CTP target mismatch profile (TMM) identifies patients likely to benefit from IAT.

Methods: The CTP to predict Response to recanalization in Ischemic Stroke Project (CRISP) is an NIH funded multicenter cohort study of consecutive acute stroke patients scheduled to undergo IAT within 90 min after a baseline CTP. Volumes for the CTP ischemic core (rCBF<30%) and critically hypoperfused tissue (Tmax>6s) were computed with automated software (RAPID). Target Mismatch (TMM) was defined as a CBF core <70 mL, a Tmax>6s – core difference >15mL, a Tmax>6s : core ratio >1.8, and a Tmax>10s lesion <100 mL. Reperfusion was defined as >50% reduction in Tmax>6s lesion volume between baseline CTP and follow-up MRI (obtained <36 hrs after CTP), or TICI 2b/3 at completion of IAT if follow-up MRI was not performed/technically inadequate. Good functional outcome (GFO) was defined as mRS 0-2 on day 90.

Results: Of the 201 patients enrolled, 6 had inadequate baseline CTP (3%), 3 did not undergo angiography, and 2 were lost to follow-up. Therefore, 190 patients were included; mean age 66 yrs, median NIHSS 16, median time from symptom onset to IAT 5.2 hrs (>6 hrs in 40%). Rate of reperfusion was 89% (87% TICI 2b/3) and 55% had GFO. In patients with TMM (n=131), reperfusion was associated with higher odds of GFO (66% vs 29%; OR=4.3; 95% CI 1.4-13). This association remained significant when adjusted for age and NIHSS (OR=8.4; 95% CI 2.5-28). In patients without TMM (n=51), the effect of reperfusion could not be assessed, since almost all patients (95%) reperfused. Independent of reperfusion status, patients with TMM had a higher rate of GFO (61%) than those without TMM (42%, p=0.02).

Conclusion: In this multicenter study, a technically adequate baseline CTP was obtained in nearly all patients and almost half underwent IAT beyond 6 hrs. Patients with the TMM profile had a high rate of GFO (61%) and a robust association between reperfusion and good outcome. These results support the feasibility of a randomized trial of IAT in an extended window using the CTP-TMM profile for patient selection.

Abstract WMP11: Arterial Occlusive Lesion Location Does Not Impact Functional Outcome in Patients with Endovascular Reperfusion

Introduction: The relationship between clinical outcome and arterial occlusive lesion (AOL) location in patients after endovascular therapy is not fully determined. We aimed to investigate if the location of the arterial occlusive lesion (AOL) is an independent predictor of good functional outcome.

Hypothesis: AOL location impacts clinical outcome with distal lesions having higher rates of good functional outcome (GFO) in reperfused patients.

Methods: Using data from the CTP to predict Response to recanalization in Ischemic Stroke Project (CRISP), a multi-center, NIH-sponsored prospective cohort study, we analyzed the effect of AOL location on clinical outcome. Patients were included if they had documented reperfusion on early follow-up MR or CT perfusion imaging (>50% reduction in Tmax>6s lesion volume) or on angiography (TICI 2b or 3). Good functional outcome was defined as mRS score 0-2 at day 90. AOL location was categorized as proximal ICA, distal ICA, MCA-M1, or MCA-M2. Fully automated perfusion software (RAPID) was used to calculate CTP infarct core volume (rCBF<30%) and critically hypoperfused tissue volume (Tmax>6s). We assessed whether age, NIHSS score, infarct core, critically hypoperfused tissue, and AOL are associated with GFO using univariate and multivariate analyses.

Results: The analysis included 167 of 201 patients (proximal ICA=21, distal ICA=32, M1=99, M2=15). Median NIHSS score (IQR) for groups were respectively: 18(14-22), 18(15-23), 17(11-20), 15( 13-19). Mean core volumes (mL) (IQR) were: 24.2(1.1-22.9), 13.0(0.0-17.7), 16.5(0.0-26.2), 10.6(1.1-13.0). Significant independent predictors of GFO were age (OR 0.82 for every 5 year increment, 95% CI 0.72-0.94), NIHSS score (OR 0.86, 95% CI 0.79-0.93), and core volume (OR 0.78 for every 10 mL increase, 95% CI 0.62-0.94), whereas AOL location (p=0.8-0.9) and the volume of critically hypoperfused tissue (p=0.5) were not significant in univariate and multivariate analyses.

Conclusion: Baseline symptom severity, infarct core volume, and age drive functional outcomes in stroke patients with successful endovascular reperfusion. These variables, but not AOL location and volume of critically hypoperfused tissue, should be used for prognostication in the acute setting.

Abstract W P348: Evaluating Gaps in the Continuum of Stroke Care

Background and Purpose: Medication adherence is an important factor for secondary stroke prevention in ambulatory care. We aimed to evaluate short-term adherence to antihypertensive and lipid-lowering agents after a new ischemic stroke as a predictor of adherence at one and two years after discharge.

Methods: A five-year cohort (2003-2008) of patients from eleven institutions participating in the Registry of the Canadian Stroke Network (RCSN) was linked to population-based administrative health records. Patients with a diagnosis of an acute ischemic stroke who were discharged home were included in the study. Medication adherence was assessed through documentation of a filled prescription at seven days, one year and two years from hospital discharge.

Results: From 2003 to 2008, 6,437 ischemic stroke patients were discharged home from hospital. A total of 1126 patients filled a prescription for antihypertensive and lipid-lowering agents within 7 days of hospital discharge. Patients provided with a prescription at discharge were more likely to be adherent to antihypertensive and lipid-lowering agents at seven days than patients who did not receive a prescription . Adherence at one year (X% vs Y%, p-value=?) was higher in patients who demonstrated adherence at seven days from discharge for antihypertensive (93.8% vs 87.7%, p<0.0001), lipid-lowering agents (88% vs 81.9%, p<0.0001), or both (85.8% vs 79.9%, p<0.0001). Similar findings are noted at two years for antihypertensives (92.2% vs 87.7%, p=0.0003), lipid-lowering agents (82.6% vs 79.0%, p=0.0394), or both (81.1% vs 77.0%, p=0.0099).

Conclusion: Filling prescriptions within one week of discharge from hospital for acute ischemic stroke predicts adherence for secondary preventive therapies at one and two years. Provision of a prescription at the time of discharge to both prior and new users of anti-hypertensive and lipid-lowering drugs is a simple and effective intervention to improve adherence to secondary preventive medications at seven days, one year and two years after ischemic stroke.

Analysis of gene expression in Treponema denticola with differential display polymerase chain reaction

Treponema denticola is an oral spirochete associated with the periodontal diseases. A great deal of the molecular components of T. denticola will be learned soon since its genome sequence project is on the way. One of the most important works after genome sequence is to analyze the function of these genes and their regulation. However, like many other oral pathogens, there are currently a very limited number of molecular and genetic tools available to study gene expression in T. denticola. In this article, we describe a method of adapting differential display polymerase chain reaction (ddPCR) for use in the T. denticola system. To test for effectiveness of this protocol, we used three different temperature conditions, 4 degrees C, 25 degrees C and 42 degrees C, to test for differential gene expression. With various ddPCR conditions, we found a number of genes that were expressed differentially. Some of these differentially expressed genes were cloned and sequenced and found to be homologous with the known temperature-regulated genes, including HtrA. The study indicates that the ddPCR method can be effectively used in T. denticola for analyzing gene expression under various conditions.