Hemorrhage rates in patients with acute ischemic stroke treated with intravenous alteplase and thrombectomy versus thrombectomy alone.

BACKGROUND: Intravenous alteplase treatment (IVT) for acute ischemic stroke carries a risk of intracranial hemorrhage (ICH). However, reperfusion of an occluded vessel itself may contribute to the risk of ICH. We determined whether IVT and reperfusion are associated with ICH or its volume in the Multicenter Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands (MR CLEAN)-NO IV trial. METHODS: The MR CLEAN-NO IV trial randomized patients with acute ischemic stroke due to large vessel occlusion to receive either IVT followed by endovascular treatment (EVT) or EVT alone. ICH was classified according to the Heidelberg bleeding classification on follow-up MRI or CT approximately 8 hours-7 days after stroke. Hemorrhage volume was measured with ITK-snap. Successful reperfusion was defined as extended Thrombolysis In Cerebral Infarction (eTICI) score of 2b-3. Multinomial and binary adjusted logistic regression were used to determine the association of IVT and reperfusion with ICH subtypes. RESULTS: Of 539 included patients, 173 (32%) developed ICH and 30 suffered from symptomatic ICH (sICH) (6%). Of the patients with ICH, 102 had hemorrhagic infarction, 47 had parenchymal hematoma, 44 had SAH, and six had other ICH. Reperfusion was associated with a decreased risk of SAH, and IVT was not associated with SAH (eTICI 2b-3: adjusted OR 0.45, 95% CI 0.21 to 0.97; EVT without IVT: OR 1.6, 95% CI 0.91 to 2.8). Reperfusion status and IVT were not associated with overall ICH, hemorrhage volume, and sICH (sICH: EVT without IVT, OR 0.96, 95% CI 0.41 to 2.25; eTICI 2b-3, OR 0.49, 95% CI 0.23 to 1.05). CONCLUSION: Neither IVT administration before EVT nor successful reperfusion after EVT were associated with ICH, hemorrhage volume, and sICH. SAH occurred more often in patients for whom successful reperfusion was not achieved.

Thrombus radiomics in patients with anterior circulation acute ischemic stroke undergoing endovascular treatment.

BACKGROUND: Thrombus radiomics (TR) describe complex shape and textural thrombus imaging features. We aimed to study the relationship of TR extracted from non-contrast CT with procedural and functional outcome in endovascular-treated patients with acute ischemic stroke. METHODS: Thrombi were segmented on thin-slice non-contrast CT (≤1 mm) from 699 patients included in the MR CLEAN Registry. In a pilot study, we selected 51 TR with consistent values across two raters' segmentations (ICC >0.75). Random forest models using TR in addition or as a substitute to baseline clinical variables (CV) and manual thrombus measurements (MTM) were trained with 499 patients and evaluated on 200 patients for predicting successful reperfusion (extended Thrombolysis in Cerebral Ischemia (eTICI) ≥2B), first attempt reperfusion, reperfusion within three attempts, and functional independence (modified Rankin Scale (mRS) ≤2). Three texture and shape features were selected based on feature importance and related to eTICI ≥2B, number of attempts to eTICI ≥2B, and 90-day mRS with ordinal logistic regression. RESULTS: Random forest models using TR, CV or MTM had comparable predictive performance. Thrombus texture (inverse difference moment normalized) was independently associated with reperfusion (adjusted common OR (acOR) 0.85, 95% CI 0.72 to 0.99). Thrombus volume and texture were also independently associated with the number of attempts to successful reperfusion (acOR 1.36, 95% CI 1.03 to 1.88 and acOR 1.24, 95% CI 1.04 to 1.49). CONCLUSIONS: TR describing thrombus volume and texture were associated with more attempts to successful reperfusion. Compared with models using CV and MTM, TR had no added value for predicting procedural and functional outcome.

Influence of time metrics on the treatment effect of intravenous alteplase prior to endovascular treatment in MR CLEAN-NO IV.

BACKGROUND: We assessed whether the treatment effect of intravenous alteplase (IVT) prior to endovascular treatment (EVT) on functional outcome is modified by time metrics. METHODS: We used data from all patients included in MR CLEAN-NO IV, a randomized trial of IVT followed by EVT versus EVT alone in patients who presented directly to EVT-capable hospitals. The primary outcome was the modified Rankin Scale score at 90 days. We used ordinal regression with a multiplicative interaction term to assess if the effect of IVT is modified by onset-to-randomization (OTR), onset-to-IV-needle (OTN), door-to-groin (DTG) or needle-to-groin (NTG) times. Secondary outcomes included successful reperfusion (extended Thrombolysis In Cerebral Infarction Scale 2b-3) and symptomatic intracranial hemorrhage (sICH). RESULTS: In 539 included patients (266 allocated to IVT+EVT and 273 to EVT alone), median workflow times were OTR: 93 (IQR 71-145) min; OTN: 98 (IQR 75-156) min; DTG: 64 (IQR 51-78) min; and NTG: 28 (IQR 20-41) min. There was a significant association between worse outcomes and longer time intervals for all metrics except NTG. We found no interaction between any of the time metrics and IVT for the effect on functional outcome (p values for interaction: OTR=0.40, OTN=0.39, DTG=0.61, NTG=0.56). We also did not observe any significant interaction for successful reperfusion or sICH. CONCLUSION: In MR CLEAN-NO IV, the effect of IVT prior to EVT was not modified by OTR, OTN, DTG or NTG times. Our results do not support the use of these metrics to guide IVT treatment decisions prior to EVT in comprehensive stroke centres. TRIAL REGISTRATION NUMBER: ISRCTN80619088.

Endovascular treatment for isolated posterior cerebral artery occlusion stroke in the MR CLEAN registry.

BACKGROUND: Endovascular treatment (EVT) is standard of care in anterior circulation large vessel occlusions. In posterior circulation occlusions, data on EVT in isolated posterior cerebral artery (PCA) occlusions are limited, although PCA occlusions can cause severe neurological deficit. OBJECTIVE: To describe in a prospective study the clinical manifestations, outcomes, and safety of EVT in isolated PCA occlusions. METHODS: We used data (2014-2017) from the MR CLEAN Registry, a nationwide, prospective cohort of EVT-treated patients in the Netherlands. We included patients with acute ischemic stroke (AIS) due to an isolated PCA occlusion on CT angiography. Patients with concurrent occlusion of the basilar artery were excluded. Outcomes included change in National Institutes of Health Stroke Scale (ΔNIHSS) score, modified Rankin Scale (mRS) score 0-3 after 90 days, mortality, expanded Thrombolysis in Cerebral Infarction (eTICI), and periprocedural complications. RESULTS: Twenty (12%) of 162 patients with posterior circulation occlusions had an isolated PCA occlusion. Median age was 72 years; 13 (65%) were women. Median baseline NIHSS score was 13 (IQR 5-21). Six (30%) patients were comatose. Twelve patients (60%) received IVT. Median ΔNIHSS was -4 (IQR -11-+1). At follow-up, nine patients (45%) had mRS score 0-3. Seven (35%) died. eTICI 2b-3 was achieved in 13 patients (65%). Nine patients (45%) had periprocedural complications. No symptomatic intracranial hemorrhages (sICH) occurred. CONCLUSIONS: EVT should be considered in selected patients with AIS with an isolated PCA occlusion, presenting with moderate-severe neurological deficits, as EVT was technically feasible in most of our patients and about half had good clinical outcome. In case of lower NIHSS score, a more conservative approach seems warranted, since periprocedural complications are not uncommon. Nonetheless, EVT seems reasonably safe considering the absence of sICH in our study.

Perceived acceptable uncertainty regarding comparability of endovascular treatment alone versus intravenous thrombolysis plus endovascular treatment.

BACKGROUND: Most trials comparing endovascular treatment (EVT) alone versus intravenous thrombolysis with alteplase (IVT) + EVT in directly admitted patients with a stroke are non-inferiority trials. However, the margin based on the level of uncertainty regarding non-inferiority of the experimental treatment that clinicians are willing to accept to incorporate EVT alone into clinical practice remains unknown. OBJECTIVE: To characterize what experienced stroke clinicians would consider an acceptable level of uncertainty for hypothetical decisions on whether to administer IVT or not before EVT in patients admitted directly to EVT-capable centers. METHODS: A web-based, structured survey was distributed to a cross-section of 600 academic neurologists/neurointerventionalists. For this purpose, a response framework for a hypothetical trial comparing IVT+EVT (standard of care) with EVT alone (experimental arm) was designed. In this trial, a similar proportion of patients in each arm achieved functional independence at 90 days. Invited physicians were asked at what level of certainty they would feel comfortable skipping IVT in clinical practice, considering these hypothetical trial results. RESULTS: There were 180 respondents (response rate: 30%) and 165 with complete answers. The median chosen acceptable uncertainty suggesting reasonable comparability between both treatments was an absolute difference in the rate of day 90 functional independence of 3% (mode 5%, IQR 1-5%), with higher chosen margins observed in interventionalists (aOR 2.20, 95% CI 1.06 to 4.67). CONCLUSION: Physicians would generally feel comfortable skipping IVT before EVT at different certainty thresholds. Most physicians would treat with EVT alone if randomized trial data suggested that the number of patients achieving functional independence at 90 days was similar between the two groups, and one could be sufficiently sure that no more than 3 out of 100 patients would not achieve functional independence at 90 days due to skipping IVT.

Bifurcation occlusions and endovascular treatment outcome in acute ischemic stroke.

BACKGROUND: A thrombus in the M1 segment of the middle cerebral artery (MCA) can occlude this main stem only or extend into the M1-M2 bifurcation. The occlusion pattern may affect endovascular treatment (EVT) success, as a bifurcated thrombus may be more prone to fragmentation during retrieval. OBJECTIVE: To investigate whether bifurcated thrombus patterns are associated with EVT procedural and clinical outcomes. METHODS: Occlusion patterns of MCA thrombi on CT angiography from MR CLEAN Registry patients were classified into three groups: main stem occlusion, bifurcation occlusion extending into one M2 branch, and bifurcation occlusion extending into both M2 branches. Procedural parameters, procedural outcomes (reperfusion grade and embolization to new territory), and clinical outcomes (24-48 hour National Institutes of Health Stroke Scale [NIHSSFU] score, change in NIHSS scores between 24 and 48 hours and baseline ∆ [NIHSS], and 90-day modified Rankin Scale [mRS] scores) were compared between occlusion patterns. RESULTS: We identified 1023 patients with an MCA occlusion of whom 370 (36%) had a main stem occlusion, 151 (15%) a single branch, and 502 (49%) a double branch bifurcation occlusion. There were no statistically significant differences in retrieval method, procedure time, number of retrieval attempts, reperfusion grade, and embolization to new territory between occlusion patterns. Patients with main stem occlusions had lower NIHSSFU scores than patients with single (7 vs 11, p=0.01) or double branch occlusions (7 vs 9, p=0.04). However, there were no statistically significant differences in ∆ NIHSS or in 90-day mRS scores. CONCLUSIONS: In our population, EVT procedural and long-term clinical outcomes were similar for MCA bifurcation occlusions and MCA main stem occlusions.

Clinical Outcome After Endovascular Treatment in Patients With Active Cancer and Ischemic Stroke: A MR CLEAN Registry Substudy.

BACKGROUND AND OBJECTIVES: To explore clinical and safety outcomes of patients with acute ischemic stroke (AIS) and active cancer after endovascular treatment (EVT). METHODS: Using data from the Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands (MR CLEAN) Registry, we compared patients with active cancer (defined as cancer diagnosed within 12 months before stroke, metastatic disease, or current cancer treatment) to patients without cancer. Outcomes were 90-day modified Rankin Scale (mRS) score, mortality, successful reperfusion (expanded Treatment in Cerebral Infarction score ≥2b), symptomatic intracranial hemorrhage (sICH), and recurrent stroke. Subgroup analyses were performed in patients with a prestroke mRS score of 0 or 1 and according to treatment setting (curative or palliative). Analyses were adjusted for prognostic variables. RESULTS: Of 2,583 patients who underwent EVT, 124 (4.8%) had active cancer. They more often had prestroke disability (mRS score ≥2: 34.1% vs 16.6%). The treatment setting was palliative in 25.3% of the patients. There was a shift toward worse functional outcome at 90 days in patients with active cancer (adjusted common odds ratio [acOR] 2.2, 95% confidence interval [CI] 1.5-3.2). At 90 days, patients with active cancer were less often independent (mRS score 0-2: 22.6% vs 42.0%, adjusted OR [aOR] 0.5, 95% CI 0.3-0.8) and more often dead (52.2% vs 26.5%, aOR 3.2, 95% CI 2.1-4.9). Successful reperfusion (67.8% vs 60.5%, aOR 1.4, 95% CI 1.0-2.1) and sICH rates (6.5% vs 5.9%, aOR 1.1, 95% CI 0.5-2.3) did not differ. Recurrent stroke within 90 days was more common in patients with active cancer (4.0% vs 1.3%, aOR 3.1, 95% CI 1.2-8.1). The sensitivity analysis of patients with a prestroke mRS score of 0 or 1 showed that patients with active cancer still had a worse outcome at 90 days (acOR 1.9, 95% CI 1.2-3.0). Patients with active cancer in a palliative treatment setting regained functional independence less often compared to patients in a curative setting (18.2% vs 32.1%), and mortality was higher (81.8% vs 39.3%). DISCUSSION: Despite similar technical success, patients with active cancer had significantly worse outcomes after EVT for AIS. Moreover, they had an increased risk of recurrent stroke. Nevertheless, about a quarter of the patients regained functional independence, and the risk of other complications, most notably sICH, was not increased. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that patients with active cancer undergoing EVT for AIS have worse functional outcomes at 90 days compared to those without active cancer.

Predictors of poor outcome despite successful endovascular treatment for ischemic stroke: results from the MR CLEAN Registry.

BACKGROUND: Approximately one-third of patients with ischemic stroke treated with endovascular treatment do not recover to functional independence despite rapid and successful recanalization. We aimed to quantify the importance of predictors of poor functional outcome despite successful reperfusion. METHODS: We analyzed patients from the MR CLEAN Registry between March 2014 and November 2017 with successful reperfusion (extended Thrombolysis In Cerebral Infarction ≥2B). First, predictors were selected based on expert opinion and were clustered according to acquisition over time (ie, baseline patient factors, imaging factors, treatment factors, and postprocedural factors). Second, several models were constructed to predict 90-day functional outcome (modified Rankin Scale (mRS)). The relative importance of individual predictors in the most extensive model was expressed by the proportion of unique added χ2 to the model of that individual predictor. RESULTS: Of 3180 patients, 1913 (60%) had successful reperfusion. Of these 1913 patients, 1046 (55%) were functionally dependent at 90 days (mRS >2). The most important predictors for mRS were baseline patient factors (ie, pre-stroke mRS, added χ2 0.16; National Institutes of Health Stroke Scale score at baseline, added χ2 0.12; age, added χ2 0.10), and postprocedural factors (ie, symptomatic intracranial hemorrhage (sICH), added χ2 0.12; pneumonia, added χ2 0.09). The probability of functional independence for a typical stroke patient with sICH was 54% (95% CI 36% to 72%) lower compared with no sICH, and 21% (95% CI 4% to 38%) for pneumonia compared with no pneumonia. CONCLUSION: Baseline patient factors and postprocedural adverse events are important predictors of poor functional outcome in successfully reperfused patients with ischemic stroke. This implies that prevention of postprocedural adverse events has the greatest potential to further improve outcomes in these patients.

Early recanalization in large-vessel occlusion stroke patients transferred for endovascular treatment.

BACKGROUND: We performed an exploratory analysis to identify patient and thrombus characteristics associated with early recanalization in large-vessel occlusion (LVO) stroke patients transferred for endovascular treatment (EVT) from a primary (PSC) to a comprehensive stroke center (CSC). METHODS: We included patients with an LVO stroke of the anterior circulation who were transferred to our hospital for EVT and underwent repeated imaging between January 2016 and June 2019. We compared patient characteristics, workflow time metrics, functional outcome (modified Rankin Scale at 90 days), and baseline thrombus imaging characteristics, which included: occlusion location, thrombus length, attenuation, perviousness, distance from terminus of intracranial carotid artery to the thrombus (DT), and clot burden score (CBS), between early-recanalized LVO (ER-LVO), and non-early-recanalized LVO (NER-LVO) patients. RESULTS: One hundred and forty-nine patients were included in the analysis. Early recanalization occurred in 32% of patients. ER-LVO patients less often had a medical history of hypertension (31% vs 49%, P=0.04), and more often had clinical improvement between PSC and CSC (ΔNIHSS -5 vs 3, P<0.01), compared with NER-LVO patients. Thrombolysis administration was similar in both groups (88% vs 78%, P=0.18). ER-LVO patients had no ICA occlusions (0% vs 27%, P<0.01), more often an M2 occlusion (35% vs 17%, P=0.01), longer DT (27 mm vs 12 mm, P<0.01), shorter thrombi (17 mm vs 27 mm, P<0.01), and higher CBS (8 vs 6, P<0.01) at baseline imaging. ER-LVO patients had lower mRS scores (1 vs 3, P=0.02). CONCLUSIONS: Early recanalization is associated with clinical improvement between PSC and CSC admission, more distal occlusions and shorter thrombi at baseline imaging, and better functional outcome.

Value of repeated imaging in patients with a stroke who are transferred for endovascular treatment.

BACKGROUND: Patients with a stroke who are transferred to a comprehensive stroke center for endovascular treatment (EVT) often undergo repeated neuroimaging prior to EVT. OBJECTIVE: To evaluate the yield of repeating imaging and its effect on treatment times. METHODS: We included adult patients with a large vessel occlusion (LVO) stroke who were referred to our hospital for EVT by primary stroke centers (2016-2019). We excluded patients who underwent repeated imaging because primary imaging was unavailable, incomplete, or of insufficient quality. Outcomes included treatment times and repeated imaging findings. RESULTS: Of 677 transferred LVO stroke, 551 were included. Imaging was repeated in 165/551 patients (30%), mostly because of clinical improvement (86/165 (52%)) or deterioration (40/165 (24%)). Patients who underwent repeated imaging had higher door-to-groin-times than patients without repeated imaging (median 43 vs 27 min, adjusted time difference: 20 min, 95% CI 15 to 25). Among patients who underwent repeated imaging because of clinical improvement, the LVO had resolved in 50/86 (58%). In patients with clinical deterioration, repeated imaging led to refrainment from EVT in 3/40 (8%). No symptomatic intracranial hemorrhages (sICH) were identified. Ultimately, 75/165 (45%) of patients with repeated imaging underwent EVT compared with 326/386 (84%) of patients without repeated imaging (p<0.01). CONCLUSIONS: Neuroimaging was repeated in 30% of patients with an LVO stroke and resulted in a median treatment delay of 20 minutes. In patients with clinical deterioration, no sICH were detected and repeated imaging rarely changed the indication for EVT. However, in more than half of patients with clinical improvement, the LVO had resolved, resulting in refrainment from EVT.

Quantified health and cost effects of faster endovascular treatment for large vessel ischemic stroke patients in the Netherlands.

BACKGROUND: The effectiveness of endovascular treatment (EVT) for large vessel occlusion (LVO) stroke severely depends on time to treatment. However, it remains unclear what the value of faster treatment is in the years after index stroke. The aim of this study was to quantify the value of faster EVT in terms of health and healthcare costs for the Dutch LVO stroke population. METHODS: A Markov model was used to simulate 5-year follow-up functional outcome, measured with the modified Rankin Scale (mRS), of 69-year-old LVO patients. Post-treatment mRS was extracted from the MR CLEAN Registry (n=2892): costs per unit of time and Quality-Adjusted Life Years (QALYs) per mRS sub-score were retrieved from follow-up data of the MR CLEAN trial (n=500). Net Monetary Benefit (NMB) at a willingness to pay of €80 000 per QALY was reported as primary outcome, and secondary outcome measures were days of disability-free life gained and costs. RESULTS: EVT administered 1 min faster resulted in a median NMB of €309 (IQR: 226;389), 1.3 days of additional disability-free life (IQR: 1.0;1.6), while cumulative costs remained largely unchanged (median: -€15, IQR: -65;33) over a 5-year follow-up period. As costs over the follow-up period remained stable while QALYs decreased with longer time to treatment, which this results in a near-linear decrease of NMB. Since patients with faster EVT lived longer, they incurred more healthcare costs. CONCLUSION: One-minute faster EVT increases QALYs while cumulative costs remain largely unaffected. Therefore, faster EVT provides better value of care at no extra healthcare costs.

Automatic segmentation of cerebral infarcts in follow-up computed tomography images with convolutional neural networks.

BACKGROUND AND PURPOSE: Infarct volume is a valuable outcome measure in treatment trials of acute ischemic stroke and is strongly associated with functional outcome. Its manual volumetric assessment is, however, too demanding to be implemented in clinical practice. OBJECTIVE: To assess the value of convolutional neural networks (CNNs) in the automatic segmentation of infarct volume in follow-up CT images in a large population of patients with acute ischemic stroke. MATERIALS AND METHODS: We included CT images of 1026 patients from a large pooling of patients with acute ischemic stroke. A reference standard for the infarct segmentation was generated by manual delineation. We introduce three CNN models for the segmentation of subtle, intermediate, and severe hypodense lesions. The fully automated infarct segmentation was defined as the combination of the results of these three CNNs. The results of the three-CNNs approach were compared with the results from a single CNN approach and with the reference standard segmentations. RESULTS: The median infarct volume was 48 mL (IQR 15-125 mL). Comparison between the volumes of the three-CNNs approach and manually delineated infarct volumes showed excellent agreement, with an intraclass correlation coefficient (ICC) of 0.88. Even better agreement was found for severe and intermediate hypodense infarcts, with ICCs of 0.98 and 0.93, respectively. Although the number of patients used for training in the single CNN approach was much larger, the accuracy of the three-CNNs approach strongly outperformed the single CNN approach, which had an ICC of 0.34. CONCLUSION: Convolutional neural networks are valuable and accurate in the quantitative assessment of infarct volumes, for both subtle and severe hypodense infarcts in follow-up CT images. Our proposed three-CNNs approach strongly outperforms a more straightforward single CNN approach.

Comparison of three commonly used CT perfusion software packages in patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: CT perfusion (CTP) might support decision making in patients with acute ischemic stroke by providing perfusion maps of ischemic tissue. Currently, the reliability of CTP is hampered by varying results between different post-processing software packages. The purpose of this study is to compare ischemic core volumes estimated by IntelliSpace Portal (ISP) and syngo.via with core volumes as estimated by RAPID. METHODS: Thirty-five CTP datasets from patients in the MR CLEAN trial were post-processed. Core volumes were estimated with ISP using default settings and with syngo.via using three different settings: default settings (method A); additional smoothing filter (method B); and adjusted settings (method C). The results were compared with RAPID. Agreement between methods was assessed using Bland-Altman analysis and intraclass correlation coefficient (ICC). Accuracy for detecting volumes up to 25 mL, 50 mL, and 70 mL was assessed. Final infarct volumes were determined on follow-up non-contrast CT. RESULTS: Median core volume was 50 mL with ISP, 41 mL with syngo.via method A, 20 mL with method B, 36 mL with method C, and 11 mL with RAPID. Agreement ranged from poor (ISP: ICC 0.41; method A: ICC 0.23) to good (method B: ICC 0.83; method C: ICC 0.85). The bias (1.8 mL) and limits of agreement (-27, 31 mL) were the smallest with syngo.via with additional smoothing (method B). Agreement for detecting core volumes ≤25 mL with ISP was 54% and 57%, 85% and 74% for syngo.via methods A, B, and C, respectively. CONCLUSION: Best agreement with RAPID software is provided by syngo.via default settings with additional smoothing. Moreover, this method has the highest agreement in categorizing patients with small core volumes.

Efficacy of endovascular thrombectomy in patients with M2 segment middle cerebral artery occlusions: meta-analysis of data from the HERMES Collaboration.

BACKGROUND: The Society of Neurointerventional Surgery revised its operational definition of emergent large vessel occlusion (ELVO) recently to include proximal M2 segment middle cerebral artery (MCA) occlusions. We sought to assess the benefit of endovascular thrombectomy (EVT) over best medical care for M2 segment MCA occlusion. METHODS: Patient level data from trials in the HERMES Collaboration were included. The HERMES core laboratory identified patients with M2 segment MCA occlusions and further classified them as proximal versus distal, anterior versus posterior division, and dominant versus co-dominant versus non-dominant. Primary outcome was modified Rankin Scale (mRS) score 0-2 at 90 days. Secondary outcomes were modified Thrombolysis in Cerebral Infarction (mTICI) rates at end of procedure, 90-day mRS shift, 90-day mRS 0-1, 24 hours National Institute of Health Stroke Scale (NIHSS) score 0-2, symptomatic intracerebral hemorrhage (ICH), and death. RESULTS: 130 patients with M2 MCA (proximal location n=116 vs distal n=14, anterior division n=72 vs posterior n=58, dominant n=73 vs co-dominant n=50 vs non-dominant n=7) were included. Successful reperfusion (mTICI 2b or 3) among those undergoing EVT was seen in 59.2% of patients. Treatment effect favored EVT (adjusted OR 2.39, 95% CI 1.08 to 5.28, p=0.03) for 90-day mRS 0-2 (58.2% EVT vs 39.7% control). Direction of benefit favored EVT for other outcomes. Treatment effect favoring EVT was maximal in patients with proximal M2 segment MCA occlusions (n=116, adjusted OR 2.68, 95% CI 1.13 to 6.37) and in dominant M2 segment MCA occlusions (n=73, adjusted OR 4.08, 95% CI 1.08 to 15.48). No sICH (0%) was observed in patients treated with EVT compared with five (7.9%) in the control arm. CONCLUSION: Patients with proximal M2 segment MCA occlusions eligible for EVT trial protocols benefited from EVT.

Equal performance of aspiration and stent retriever thrombectomy in daily stroke treatment.

BACKGROUND: Mechanical thrombectomy with stent retrievers has proved to be safe and effective in endovascular treatment of acute ischemic stroke. Direct aspiration has shown revascularization rates comparable to those of stent retrievers in the recent ASTER and COMPASS trials. However, the efficacy of aspiration in routine clinical practice has not yet been shown. OBJECTIVE: To show that aspiration has clinical and technical outcomes equal to those of stent retriever thrombectomy in daily clinical practice. METHODS: We analysed data of patients with a large vessel occlusion of the anterior circulation registered in the Dutch MR CLEAN Registry between March 2014 and June 2016. Primary outcome was functional outcome measured with the modified Rankin Scale (mRS) score. Secondary outcomes were reperfusion grade, periprocedural complication rate, and procedure duration. Association of treatment technique with functional outcome was estimated with univariable and multivariable ordinal logistic regression analysis and expressed as a common OR (cOR) for a shift towards better outcome on the mRS. RESULTS: As first-line treatment, 207 of 1175 patients (17.6%) were treated with direct aspiration, and 968 (82.4%) by a stent retriever. We observed no differences in functional outcome (adjusted cOR=1.020 (95% CI 0.68 to 1.52)) and periprocedural complications. Successful reperfusion (extended Thrombolysis in Cerebral Infarction ≥2b) was similar. Duration of the procedure was shorter with aspiration (57 min (IQR 35-73) vs 70 min (IQR 47-95), p<0.0001). CONCLUSION: Direct aspiration shows clinical outcomes equal to those of stent retriever thrombectomy in our large multicenter real-life cohort. We found no difference in complication rates and shorter procedure times for aspiration.

Hemorrhagic transformation is associated with poor functional outcome in patients with acute ischemic stroke due to a large vessel occlusion.

BACKGROUND AND PURPOSE: Hemorrhagic transformation (HT) is a complication that may cause neurological deterioration in patients with acute ischemic stroke. Various radiological subtypes of HT can be distinguished. Their influence on functional outcome is currently unclear. The purpose of this study was to assess the associations between HT subtypes and functional outcome in acute ischemic stroke patients with proven large vessel occlusion included in the MR CLEAN trial (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic stroke in The Netherlands). METHODS: All patients with follow-up imaging were included. HT was classified on follow-up CT scans according to the European Cooperative Acute Stroke Study II classification. Functional outcome was assessed using the modified Rankin Scale (mRS) 90 days after stroke onset. Ordinal logistic regression analysis with adjustment for potential confounders was used to determine the association of HT subtypes with functional outcome. RESULTS: Of 478 patients, 222 had HT. Of these, 76 (16%) patients were classified as hemorrhagic infarction type 1, 71 (15%) as hemorrhagic infarction type 2, 36 (8%) as parenchymal hematoma type 1, and 39 (8%) as parenchymal hematoma type 2. Hemorrhagic infarction type 2 (adjusted common OR (acOR) 0.54, 95% CI: 0.32 to 0.89) and parenchymal hematoma type 2 (acOR 0.37, 95% CI 0.17 to 0.78) were significantly associated with a worse functional outcome. Hemorrhagic infarction type 1 and parenchymal hematoma type 1 were not significantly associated, although their point estimates pointed in the direction of worse outcome. CONCLUSION: This study suggests that parenchymal hematoma type 2 is relevant for functional outcome after an acute ischemic stroke, and smaller HTs might also influence long term functional outcome. TRAIL REGISTRATION NUMBER: ISRCTN10888758.

Association of follow-up infarct volume with functional outcome in acute ischemic stroke: a pooled analysis of seven randomized trials.

BACKGROUND: Follow-up infarct volume (FIV) has been recommended as an early indicator of treatment efficacy in patients with acute ischemic stroke. Questions remain about the optimal imaging approach for FIV measurement. OBJECTIVE: To examine the association of FIV with 90-day modified Rankin Scale (mRS) score and investigate its dependency on acquisition time and modality. METHODS: Data of seven trials were pooled. FIV was assessed on follow-up (12 hours to 2 weeks) CT or MRI. Infarct location was defined as laterality and involvement of the Alberta Stroke Program Early CT Score regions. Relative quality and strength of multivariable regression models of the association between FIV and functional outcome were assessed. Dependency of imaging modality and acquisition time (≤48 hours vs >48 hours) was evaluated. RESULTS: Of 1665 included patients, 83% were imaged with CT. Median FIV was 41 mL (IQR 14-120). A large FIV was associated with worse functional outcome (OR=0.88(95% CI 0.87 to 0.89) per 10 mL) in adjusted analysis. A model including FIV, location, and hemorrhage type best predicted mRS score. FIV of ≥133 mL was highly specific for unfavorable outcome. FIV was equally strongly associated with mRS score for assessment on CT and MRI, even though large differences in volume were present (48 mL (IQR 15-131) vs 22 mL (IQR 8-71), respectively). Associations of both early and late FIV assessments with outcome were similar in strength (ρ=0.60(95% CI 0.56 to 0.64) and ρ=0.55(95% CI 0.50 to 0.60), respectively). CONCLUSIONS: In patients with an acute ischemic stroke due to a proximal intracranial occlusion of the anterior circulation, FIV is a strong independent predictor of functional outcome and can be assessed before 48 hours, oneither CT or MRI.

A decrease in blood pressure is associated with unfavorable outcome in patients undergoing thrombectomy under general anesthesia.

BACKGROUND: Up to two-thirds of patients are either dependent or dead 3 months after thrombectomy for acute ischemic stroke (AIS). Loss of cerebral autoregulation may render patients with AIS vulnerable to decreases in mean arterial pressure (MAP). OBJECTIVE: To determine whether a fall in MAP during intervention under general anesthesia (GA) affects functional outcome. METHODS: This subgroup analysis included patients from the MR CLEAN trial treated with thrombectomy under GA. The investigated variables were the difference between MAP at baseline and average MAP during GA (ΔMAP) as well as the difference between baseline MAP and the lowest MAP during GA (ΔLMAP). Their association with a shift towards better outcome on the modified Rankin Scale (mRS) after 90 days was determined using ordinal logistic regression with adjustment for prognostic baseline variables. RESULTS: Sixty of the 85 patients treated under GA in MR CLEAN had sufficient anesthetic information available for the analysis. A greater ΔMAP was associated with worse outcome (adjusted common OR (acOR) 0.95 per point mm Hg, 95% CI 0.92 to 0.99). An average MAP during GA 10 mm Hg lower than baseline MAP constituted a 1.67 times lower odds of a shift towards good outcome on the mRS. For ΔLMAP this association was not significant (acOR 0.97 per mm Hg, 95% CI 0.94 to 1.00, p=0.09). CONCLUSIONS: A decrease in MAP during intervention under GA compared with baseline is associated with worse outcome. TRIAL REGISTRATION NUMBER: NTR1804; ISRCTN10888758; post-results.

Workflow and factors associated with delay in the delivery of intra-arterial treatment for acute ischemic stroke in the MR CLEAN trial.

OBJECTIVE: The effect of intra-arterial treatment (IAT) for acute ischemic stroke is highly time-dependent. We investigated the delay of IAT and factors associated with such delay. METHODS: MR CLEAN was a randomized trial of IAT plus usual care versus usual care alone (n=500). With multivariable linear regression, we analyzed the effect of intravenous treatment, general anesthesia, off-hours and inter-hospital transfer on time to admission to the emergency department (ED) of the intervention center and time to treatment. Furthermore, we assessed compliance with a target of 75 min for time from ED to treatment, and calculated the potential absolute increase in the number of patients with a good outcome (modified Rankin Scale score ≤2) if this target had been achieved in all treated patients. RESULTS: Inter-hospital transfer prolonged time to ED by 140 min (95% CI 129 to 150) but reduced time from ED to treatment by 77 min (95% CI 64 to 91). Time from ED to treatment was increased by 19 min by general anesthesia (95% CI 5 to 33) and total time was increased by 23 min during off-hours (95% CI 6 to 40). The in-hospital target was achieved in 11.5% (22/192) of patients. Full compliance with the target time of 75 min from ED to treatment would have increased the proportion of patients with a good outcome by 7.6% (95% CI 6.7% to 8.5%). CONCLUSION: Inter-hospital transfer is an important cause of delay in the delivery of IAT and every effort should be made to avoid transfers and reduce transfer-related delay. Furthermore, in-hospital workflow should be optimized to improve functional outcome after IAT.