Primary Thrombectomy in tPA (Tissue-Type Plasminogen Activator) Eligible Stroke Patients With Proximal Intracranial Occlusions

Ischemia-reperfusion injury: molecular mechanisms and therapeutic targets

Ischemia-reperfusion (I/R) injury paradoxically occurs during reperfusion following ischemia, exacerbating the initial tissue damage. The limited understanding of the intricate mechanisms underlying I/R injury hinders the development of effective therapeutic interventions. The Wnt signaling pathway exhibits extensive crosstalk with various other pathways, forming a network system of signaling pathways involved in I/R injury. This review article elucidates the underlying mechanisms involved in Wnt signaling, as well as the complex interplay between Wnt and other pathways, including Notch, phosphatidylinositol 3-kinase/protein kinase B, transforming growth factor-β, nuclear factor kappa, bone morphogenetic protein, N-methyl-D-aspartic acid receptor-Ca2+-Activin A, Hippo-Yes-associated protein, toll-like receptor 4/toll-interleukine-1 receptor domain-containing adapter-inducing interferon-β, and hepatocyte growth factor/mesenchymal-epithelial transition factor. In particular, we delve into their respective contributions to key pathological processes, including apoptosis, the inflammatory response, oxidative stress, extracellular matrix remodeling, angiogenesis, cell hypertrophy, fibrosis, ferroptosis, neurogenesis, and blood-brain barrier damage during I/R injury. Our comprehensive analysis of the mechanisms involved in Wnt signaling during I/R reveals that activation of the canonical Wnt pathway promotes organ recovery, while activation of the non-canonical Wnt pathways exacerbates injury. Moreover, we explore novel therapeutic approaches based on these mechanistic findings, incorporating evidence from animal experiments, current standards, and clinical trials. The objective of this review is to provide deeper insights into the roles of Wnt and its crosstalk signaling pathways in I/R-mediated processes and organ dysfunction, to facilitate the development of innovative therapeutic agents for I/R injury.

Pathophysiology and Treatment of Stroke: Present Status and Future Perspectives

Stroke is among the most prevalent causes of disability and is the second leading cause of death worldwide in Western countries [...].

Safety Outcomes of Mechanical Thrombectomy Versus Combined Thrombectomy and Intravenous Thrombolysis in Tandem Lesions

BACKGROUND

We aimed to describe the safety and efficacy of mechanical thrombectomy (MT) with or without intravenous thrombolysis (IVT) for patients with tandem lesions and whether using intraprocedural antiplatelet therapy influences MT's safety with IVT treatment.

METHODS

This is a subanalysis of a pooled, multicenter cohort of patients with acute anterior circulation tandem lesions treated with MT from 16 stroke centers between January 2015 and December 2020. Primary outcomes included symptomatic intracranial hemorrhage (sICH) and parenchymal hematoma type 2. Additional outcomes included hemorrhagic transformation, successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2b-3), complete reperfusion (modified Thrombolysis in Cerebral Infarction score 3), favorable functional outcome (90-day modified Rankin Scale score 0-2), excellent functional outcome (90-day modified Rankin Scale score 0-1), in-hospital mortality, and 90-day mortality.

RESULTS

Of 691 patients, 512 were included (218 underwent IVT+MT and 294 MT alone). There was no difference in the risk of sICH (adjusted odds ratio [aOR], 1.22 [95% CI, 0.60-2.51]; P=0.583), parenchymal hematoma type 2 (aOR, 0.99 [95% CI, 0.47-2.08]; P=0.985), and hemorrhagic transformation (aOR, 0.95 [95% CI, 0.62-1.46]; P=0.817) between the IVT+MT and MT alone groups after adjusting for confounders. Administration of IVT was associated with an increased risk of sICH in patients who received intravenous antiplatelet therapy (aOR, 3.04 [95% CI, 0.99-9.37]; P=0.05). The IVT+MT group had higher odds of a 90-day modified Rankin Scale score 0 to 2 (aOR, 1.72 [95% CI, 1.01-2.91]; P=0.04). The odds of successful reperfusion, complete reperfusion, 90-day modified Rankin Scale score 0 to 1, in-hospital mortality, or 90-day mortality did not differ between the IVT+MT versus MT alone groups.

CONCLUSIONS

Our study showed that the combination of IVT with MT for tandem lesions did not increase the overall risk of sICH, parenchymal hematoma type 2, or overall hemorrhagic transformation independently of the cervical revascularization technique used. However, intraprocedural intravenous antiplatelet therapy during acute stent implantation might be associated with an increased risk of sICH in patients who received IVT before MT. Importantly, IVT+MT treatment was associated with a higher rate of favorable functional outcomes at 90 days.

In a hub-and-spoke network, spoke-administered thrombolysis reduces mechanical thrombectomy procedure time and number of passes

BACKGROUND

The utility of intravenous thrombolysis (IVT) prior to mechanical thrombectomy (MT) in large vessel occlusion stroke (LVO) is controversial. Some data suggest IVT increases MT technical difficulty. Within our hub-and-spoke telestroke network, we examined how spoke-administered IVT affected hub MT procedure time and pass number.

METHODS

Patients presenting to 25 spoke hospitals who were transferred to the hub and underwent MT from 2018 to 2020 were identified from a prospectively maintained database. MT procedure time, fluoroscopy time, and pass number were obtained from operative reports.

RESULTS

Of 107 patients, 48 received IVT at spokes. Baseline characteristics and NIHSS were similar. The last known well (LKW)-to-puncture time was shorter among IVT patients (4.3 ± 1.9 h vs. 10.5 ± 6.5 h, p < 0.0001). In patients that received IVT, mean MT procedure time was decreased by 18.8 min (50.5 ± 29.4 vs. 69.3 ± 46.7 min, p = 0.02) and mean fluoroscopy time was decreased by 11.3 min (21.7 ± 15.8 vs. 33.0 ± 30.9 min, p = 0.03). Furthermore, IVT-treated patients required fewer MT passes (median 1 pass [IQR 1.0, 1.80] vs. 2 passes [1.0, 2.3], p = 0.0002) and were more likely to achieve reperfusion in ≤2 passes (81.3% vs. 59.3%, p = 0.01). An increased proportion of IVT-treated patients achieved TICI 2b-3 reperfusion after MT (93.9% vs. 83.8%, p = 0.045). There were no associations between MT procedural characteristics and LKW-to-puncture time.

CONCLUSION

Within our network, hub MT following spoke-administered IVT was faster, required fewer passes, and achieved improved reperfusion. This suggests spoke-administered IVT does not impair MT, but instead may enhance it.

Thrombolysis for acute ischaemic stroke: current status and future perspectives

Alteplase is currently the only approved thrombolytic agent for treatment of acute ischaemic stroke, but interest is burgeoning in the development of new thrombolytic agents for systemic reperfusion with an improved safety profile, increased efficacy, and convenient delivery. Tenecteplase has emerged as a potential alternative thrombolytic agent that might be preferred over alteplase because of its ease of administration and reported efficacy in patients with large vessel occlusion. Ongoing research efforts are also looking at potential improvements in recanalisation with the use of adjunct therapies to intravenous thrombolysis. New treatment strategies are also emerging that aim to reduce the risk of vessel reocclusion after intravenous thrombolysis administration. Other research endeavors are looking at the use of intra-arterial thrombolysis after mechanical thrombectomy to induce tissue reperfusion. The growing implementation of mobile stroke units and advanced neuroimaging could boost the number of patients who can receive intravenous thrombolysis by shortening onset-to-treatment times and identifying patients with salvageable penumbra. Continued improvements in this area will be essential to facilitate the ongoing research endeavors and to improve delivery of new interventions.

Spoke-administered thrombolysis improves large vessel occlusion early recanalization: the real-world experience of a large academic hub-and-spoke telestroke network

Introduction

Intravenous thrombolysis (IVT) prior to mechanical thrombectomy (MT) for large vessel occlusion (LVO) stroke is increasingly controversial. Recent trials support MT without IVT for patients presenting directly to MT-capable "hub" centers. However, bypassing IVT has not been evaluated for patients presenting to IVT-capable "spoke" hospitals that require hub transfer for MT. A perceived lack of efficacy of IVT to result in LVO early recanalization (ER) is often cited to support bypassing IVT, but ER data for IVT in patients that require interhospital transfer is limited. Here we examined LVO ER rates after spoke-administered IVT in our hub-and-spoke stroke network.

Methods

Patients presenting to 25 spokes before hub transfer for MT consideration from 2018-2020 were retrospectively identified from a prospectively maintained database. Inclusion criteria were pre-transfer CTA-defined LVO, ASPECTS ≥6, and post-transfer repeat vessel imaging.

Results

Of 167 patients, median age was 69 and 51% were female. 76 received spoke IVT (+spokeIVT) and 91 did not (-spokeIVT). Alteplase was the only IVT used in this study. Comorbidities and NIHSS were similar between groups. ER frequency was increased 7.2-fold in +spokeIVT patients [12/76 (15.8%) vs. 2/91 (2.2%), P<0.001]. Spoke-administered IVT was independently associated with ER (aOR=11.5, 95% CI=2.2,99.6, p<0.05) after adjusting for timing of last known well, interhospital transfer, and repeat vessel imaging. Interval NIHSS was improved in patients with ER (median -2 (IQR -6.3, -0.8) vs. 0 (-2.5, 1), p<0.05).

Conclusion

Within our network, +spokeIVT patients had a 7.2-fold increased ER relative likelihood. This real-world analysis supports IVT use in eligible patients with LVO at spoke hospitals before hub transfer for MT.

Bridging intravenous thrombolysis in patients with atrial fibrillation

Background and purpose

40% of acute ischemic stroke patients treated by mechanical thrombectomy (MT) have a clinical history of atrial fibrillation (AF). The safety of bridging intravenous thrombolysis (IVT) (MT + IVT) is currently being discussed. We aimed to analyze the interaction between oral anticoagulation (OAC) status or AF with bridging IVT, regarding the occurrence of symptomatic intracranial hemorrhage (sICH) and functional outcome.

Materials and Methods

Multicentric observational cohort study (BEYOND-SWIFT registry) of consecutive patients undergoing MT between 2010 and 2018 (n = 2,941). Multinomial regression models were adjusted for prespecified baseline and plausible pathophysiological covariates identified on a univariate analysis to assess the association of AF and OAC status with sICH and good outcomes (90-day modified Rankin Scale score 0–2).

Results

In the total cohort (median age 74, 50.6% women), 1,347 (45.8%) patients had AF. Higher admission National Institutes of Health Stroke Scale (NIHSS) score (aOR 1.04 [95% 1.02–1.06], per point of increase) and prior medication with Vitamin K antagonists (VKA) (aOR 2.19 [95% 1.27–3.66]) were associated with sICH. Neither AF itself (aOR 0.71 [95% 0.41–1.24]) nor bridging IVT (aOR 1.08 [0.67–1.75]) were significantly associated with increased sICH. Receiving bridging IVT (aOR 1.61 [95% 1.24–2.11]) was associated with good 90-day outcome, with no interaction between AF and IVT (p = 0.92).

Conclusion

Bridging IVT appears to be a reasonable clinical option in selected patients with AF. Given the increased sICH risk in patients with VKA, subgroup analysis of the randomized controlled trials should analyze whether patients with VKA might benefit from withholding bridging IVT.

Registration

clinicaltrials.gov; Unique identifier: NCT03496064.

European Stroke Organisation (ESO)-European Society for Minimally Invasive Neurological Therapy (ESMINT) expedited recommendation on indication for intravenous thrombolysis before mechanical thrombectomy in patients with acute ischemic stroke and anterior circulation large vessel occlusion

Six randomized controlled clinical trials have assessed whether mechanical thrombectomy (MT) alone is non-inferior to intravenous thrombolysis (IVT) plus MT within 4.5 hours of symptom onset in patients with anterior circulation large vessel occlusion (LVO) ischemic stroke and no contraindication to IVT. An expedited recommendation process was initiated by the European Stroke Organisation (ESO) and conducted with the European Society of Minimally Invasive Neurological Therapy (ESMINT) according to ESO standard operating procedure based on the GRADE system. We identified two relevant Population, Intervention, Comparator, Outcome (PICO) questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and wrote evidence-based recommendations. Expert opinion was provided if insufficient evidence was available to provide recommendations based on the GRADE approach.For stroke patients with anterior circulation LVO directly admitted to a MT-capable center ('mothership') within 4.5 hours of symptom onset and eligible for both treatments, we recommend IVT plus MT over MT alone (moderate evidence, strong recommendation). MT should not prevent the initiation of IVT, nor should IVT delay MT. In stroke patients with anterior circulation LVO admitted to a center without MT facilities and eligible for IVT ≤4.5 hours and MT, we recommend IVT followed by rapid transfer to a MT capable-center ('drip-and-ship') in preference to omitting IVT (low evidence, strong recommendation). Expert consensus statements on ischemic stroke on awakening from sleep are also provided. Patients with anterior circulation LVO stroke should receive IVT in addition to MT if they have no contraindications to either treatment.

EXPRESS: European Stroke Organisation (ESO) – European Society for Minimally Invasive Neurological Therapy (ESMINT) expedited recommendation on indication for intravenous thrombolysis before mechanical thrombectomy in patients with acute ischaemic stroke and anterior circulation large vessel occlusion

Six randomized controlled clinical trials have assessed whether mechanical thrombectomy (MT) alone is non-inferior to intravenous thrombolysis (IVT) plus MT within 4.5 hours of symptom onset in patients with anterior circulation large vessel occlusion (LVO) ischaemic stroke and no contraindication to IVT. An expedited recommendation process was initiated by the European Stroke Organisation (ESO) and conducted with the European Society of Minimally Invasive Neurological Therapy (ESMINT) according to ESO standard operating procedure based on the GRADE system. We identified two relevant Population, Intervention, Comparator, Outcome (PICO) questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and wrote evidence-based recommendations. Expert opinion was provided if insufficient evidence was available to provide recommendations based on the GRADE approach. For stroke patients with anterior circulation LVO directly admitted to a MT-capable centre (“mothership”) within 4.5 hours of symptom onset and eligible for both treatments, we recommend IVT plus MT over MT alone (moderate evidence, strong recommendation). MT should not prevent the initiation of IVT, nor should IVT delay MT. In stroke patients with anterior circulation LVO admitted to a centre without MT facilities and eligible for IVT ≤4.5 hrs and MT, we recommend IVT followed by rapid transfer to a MT capable-centre (“drip-and-ship”) in preference to omitting IVT (low evidence, strong recommendation). Expert consensus statements on ischaemic stroke on awakening from sleep are also provided. Patients with anterior circulation LVO stroke should receive IVT in addition to MT if they have no contraindications to either treatment.

Endovascular treatment with or without intravenous alteplase for acute ischaemic stroke due to basilar artery occlusion

Background and purpose

It remains controversial if endovascular treatment (EVT) can improve the outcome of patients with acute basilar artery occlusion (BAO). This study aims to compare the functional outcomes between EVT with and without intravenous thrombolysis (IVT) first in patients who had acute ischaemic stroke (AIS) due to BAO.

Methods

Patients who had AIS with BAO who underwent EVT within 24 hours of onset were enrolled in this multicentre cohort study, and the efficacy and safety were compared between IVT+EVT and direct EVT. The primary outcome was 90-day functional independence. All outcomes were assessed with adjusted OR (aOR) from the multivariable logistic regression. In addition, a meta-analysis was performed on all recently published pivotal studies on functional independence after EVT in patients with BAO.

Results

Of 310 enrolled patients with BAO, 241 (78%) were treated with direct EVT and 69 (22%) with IVT+EVT. Direct EVT was associated with a worse functional outcome (aOR, 0.46 (95% CI 0.24 to 0.85), p=0.01). IVT+EVT was associated with a lower percentage of patients who needed ≥3 passes of stent retriever (10.14% vs 20.75%). The meta-analysis regression revealed a potential positive correlation between bridging with IVT first and functional independence (r=0.14 (95% CI 0.05 to 0.24), p<0.01).

Conclusions

This study showed that compared with direct EVT, EVT with IVT first was associated with better functional outcomes in patients with BAO treated within 24 hours of onset. The meta-analysis demonstrated similar favourable efficacy of IVT first followed by EVT in patients with BAO.

SWIFT DIRECT: Solitaire™ With the Intention For Thrombectomy Plus Intravenous t-PA Versus DIRECT Solitaire™ Stent-retriever Thrombectomy in Acute Anterior Circulation Stroke: Methodology of a randomized, controlled, multicentre study

RATIONALE

Whether treatment with intravenous alteplase prior to mechanical thrombectomy (MT) in acute ischemic stroke patients with large vessel occlusion is beneficial remains unclear.

AIM

To determine whether patients experiencing acute ischemic stroke due to occlusion of the intracranial internal carotid artery or the M1 segment of the middle cerebral artery who are referred to an endovascular stroke center and who are candidates for intravenous alteplase will have non-inferior functional outcome at 90 days when treated with MT alone (direct MT) with stent retrievers compared to patients treated with combined intravenous thrombolysis (IVT) with alteplase plus MT (IVT + MT) with stent retrievers.

SAMPLE SIZE

To randomize 404 patients 1:1 to direct MT or combined IVT+MT.

METHODS AND DESIGN

A multicenter, prospective, randomized, open-label, blinded-endpoint (PROBE) trial utilizing an adaptive statistical design.

OUTCOMES

The primary efficacy endpoint is functional independence (modified Rankin Scale 0-2) at 90 days. Secondary clinical efficacy outcomes include change in National Institutes of Health Stroke Scale score from baseline to day 1 and health-related quality of life at 90 days. Secondary technical efficacy outcomes include successful reperfusion prior to start of MT and time from randomization to successful reperfusion. Safety outcomes include all serious adverse events, symptomatic intracranial hemorrhage, and mortality up to 90 days.

DISCUSSION

SWIFT DIRECT will inform physicians whether direct MT in acute ischemic stroke patients with large vessel occlusion is equally or more efficacious than combined treatment with intravenous alteplase and MT.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03192332.

Local Intra-arterial Thrombolysis during Mechanical Thrombectomy for Refractory Large-Vessel Occlusion: Adjunctive Chemical Enhancer of Thrombectomy

BACKGROUND AND PURPOSE

Data on adjunctive intra-arterial thrombolysis during mechanical thrombectomy for refractory thrombus are sparse. The aim of this study was to evaluate the efficacy and safety of local intra-arterial urokinase as an adjunct to mechanical thrombectomy for refractory large-vessel occlusion.

MATERIALS AND METHODS

We retrospectively evaluated patients with acute ischemic stroke who underwent mechanical thrombectomy for anterior circulation large-vessel occlusion between January 2016 and December 2019. Patients were divided into 2 groups based on the use of intra-arterial urokinase as an adjunctive therapy during mechanical thrombectomy for refractory thrombus: the urokinase and nonurokinase groups. Herein, refractory thrombus was defined as the target occlusion with minimal reperfusion (TICI 0 or 1) despite >3 attempts with conventional mechanical thrombectomy. The baseline characteristics, procedural outcomes, and clinical outcome were compared between the 2 groups.

RESULTS

One hundred fourteen cases of refractory thrombus were identified. A total of 45 and 69 patients were in the urokinase and the nonurokinase groups, respectively. The urokinase group compared with the nonurokinase group showed a higher rate of successful reperfusion (82.2% versus 63.8%, P = .034), with lower procedural times (54 versus 69 minutes, P = .137). The rates of good clinical outcome, distal embolism, and symptomatic intracranial hemorrhage were similar between the 2 groups. The use of intra-arterial urokinase (OR = 3.682; 95% CI, 1.156-11.730; P = .027) was an independent predictor of successful reperfusion.

CONCLUSIONS

The use of local intra-arterial urokinase as an adjunct to mechanical thrombectomy may be an effective and safe method that provides better recanalization than the conventional mechanical thrombectomy for refractory thrombus in patients with embolic large-vessel occlusion.

Does prior administration of rtPA influence acute ischemic stroke clot composition? Findings from the analysis of clots retrieved with mechanical thrombectomy from the RESTORE registry

BACKGROUND AND PURPOSE

There is still much debate whether bridging-therapy [intravenous thrombolysis (IVT) prior to mechanical thrombectomy (MT)] might be beneficial compared to MT alone. We investigated the effect of IVT on size and histological composition of the clots retrieved from patients undergoing bridging-therapy or MT alone.

METHODS

We collected mechanically extracted thrombi from 1000 acute ischemic stroke (AIS) patients included in RESTORE registry. Patients were grouped according to the administration (or not) of IVT before thrombectomy. Gross photos of each clot were taken and Extracted Clot Area (ECA) was measured using ImageJ software. Martius Scarlett Blue stain was used to characterize the main histological clot components [red blood cells (RBCs), fibrin (FIB), platelets/other (PTL)] and Orbit Image Analysis was used for quantification. Additionally, we calculated the area of each main component by multiplying the component percent by ECA. Chi-squared and Kruskal-Wallis tests were used for statistical analysis.

RESULTS

451 patients (45%) were treated with bridging-therapy while 549 (55%) underwent MT alone. When considering only percent histological composition, we did not find any difference in RBC% (P = 0.895), FIB% (P = 0.458) and PTL% (P = 0.905). However, bridging-therapy clots were significantly smaller than MT-alone clots [32.7 (14.8-64.9) versus 36.8 (20.1-79.8) mm², N = 1000, H1 = 7.679, P = 0.006*]. A further analysis expressing components per clot area showed that clots retrieved from bridging-therapy cases contained less RBCs [13.25 (4.29-32.06) versus 14.97 (4.93-39.80) mm², H1 = 3.637, P = 0.056] and significantly less fibrin [9.10 (4.62-17.98) versus 10.54 (5.57-22.48) mm², H1 = 7.920, P = 0.005*] and platelets/other [5.04 (2.26-11.32) versus 6.54 (2.94-13.79) mm², H1 = 9.380, P = 0.002*] than MT-alone clots.

CONCLUSIONS

Our results suggest that previous IVT administration significantly reduces thrombus size, proportionally releasing all the main histological components.

IV tPA given in the golden hour for emergent large vessel occlusion stroke improves recanalization rates and clinical outcomes

BACKGROUND

Early thrombolysis for acute ischemic stroke (AIS) due to emergent large vessel occlusion (ELVO) is associated with better clinical outcome. This is thought to be due to greater tissue salvage with earlier recanalization. We explored whether ultra-early administration of intravenous tissue plasminogen activator (IV tPA) within 60 min (Golden Hour) of symptom onset for AIS due to ELVO is associated with a higher rate of recanalization.

METHODS

We performed a retrospective analysis of recanalization rates and clinical outcomes in patients with AIS due to ELVO treated with IV tPA, comparing patients who received IV tPA within 60 min of stroke symptom onset with those treated beyond 60 min.

RESULTS

Between January 2013 and December 2016, 158 patients with AIS due to ELVO were treated with IV tPA. Of these, 25 (15.8%) patients received IV tPA within 60 min of stroke symptom onset, while the remaining 133 (84.2%) patients received IV tPA beyond 60 min. The ultra-early treatment group was found to have a higher rate of complete recanalization (28.0% vs 6.8%, 95% CI 1.78-16.63), better chance of early neurological improvement (76.0% vs 50.4%, 95% CI 1.16-8.65), favorable clinical outcomes (mRS ≤ 2 or return to premorbid mRS) (65.0% vs 36.8%, 95% CI 1.42-9.34), and lower mortality (5% vs 31.1%, 95% CI 0.01-0.74) at 90-day follow-up compared to the later treatment group.

CONCLUSION

Our data suggest that ultra-early administration of IV tPA significantly improves recanalization rates and clinical outcomes in patients with AIS due to ELVO.

Utility of Intravenous Alteplase Prior to Endovascular Stroke Treatment: A Systematic Review and Meta-analysis of RCTs

OBJECTIVE

To provide a critical appraisal on the evidence from randomized controlled clinical trials (RCTs) on the utility of direct endovascular treatment (dEVT) compared to the combination of endovascular treatment preceded by IV thrombolysis (bridging therapy [BT]) for patients with acute large vessel occlusion (LVO).

METHODS

Eligible RCTs were identified by searching Medline and Scopus. We calculated the corresponding odds ratios (ORs) and 95% confidence intervals (CIs) and pooled estimates using random-effects models. The primary outcome was the probability of modified Rankin scale (mRS) score of 0 to 2 at 3 months.

RESULTS

We included 3 studies comprising 1,092 patients. No difference between the dEVT and BT groups was detected for the outcomes of mRS score of 0 to 2 (OR 1.08, 95% CI 0.85-1.38; adjusted OR 1.11, 95% CI 0.76-1.63), mRS score of 0 to 1 (OR 1.10, 95% CI 0.84-1.43; adjusted OR 1.16, 95% CI 0.84-1.61), and functional improvement at 3 months (common OR 1.08, 95% CI 0.88-1.34; adjusted common OR 1.09, 95% CI 0.86-1.37). Patients receiving dEVT had significantly lower likelihood of successful recanalization before the endovascular procedure compared to those receiving BT (OR 0.37, 95% CI 0.18-0.77). Patients receiving dEVT had lower intracranial bleeding rates compared to those receiving BT (OR 0.67, 95% CI 0.49-0.92) but without a significant difference in the probability of symptomatic intracranial hemorrhage. No differences in all-cause mortality, serious adverse events, or procedural complications between the 2 groups were uncovered.

CONCLUSIONS

We detected no differences in functional outcomes of IV thrombolysis-eligible patients with an acute LVO receiving dEVT compared to BT. Because uncertainty for most endpoints remains large and the available data are not able to exclude the possibility of overall benefit or harm, further RCTs are needed.

Clinical and Neuroimaging Outcomes of Direct Thrombectomy vs Bridging Therapy in Large Vessel Occlusion: Analysis of the SELECT Cohort Study

OBJECTIVE

To evaluate the comparative safety and efficacy of direct endovascular thrombectomy (dEVT) compared to bridging therapy (BT; IV tissue plasminogen activator + EVT) and to assess whether BT potential benefit relates to stroke severity, size, and initial presentation to EVT vs non-EVT center.

METHODS

In a prospective multicenter cohort study of imaging selection for endovascular thrombectomy (Optimizing Patient Selection for Endovascular Treatment in Acute Ischemic Stroke [SELECT]), patients with anterior circulation large vessel occlusion (LVO) presenting to EVT-capable centers within 4.5 hours from last known well were stratified into BT vs dEVT. The primary outcome was 90-day functional independence (modified Rankin Scale [mRS] score 0-2). Secondary outcomes included a shift across 90-day mRS grades, mortality, and symptomatic intracranial hemorrhage. We also performed subgroup analyses according to initial presentation to EVT-capable center (direct vs transfer), stroke severity, and baseline infarct core volume.

RESULTS

We identified 226 LVOs (54% men, mean age 65.6 ± 14.6 years, median NIH Stroke Scale [NIHSS] score 17, 28% received dEVT). Median time from arrival to groin puncture did not differ in patients with BT when presenting directly (dEVT 1.43 [interquartile range (IQR) 1.13-1.90] hours vs BT 1.58 [IQR 1.27-2.02] hours, p = 0.40) or transferred to EVT-capable centers (dEVT 1.17 [IQR 0.90-1.48] hours vs BT 1.27 [IQR 0.97-1.87] hours, p = 0.24). BT was associated with higher odds of 90-day functional independence (57% vs 44%, adjusted odds ratio [aOR] 2.02, 95% confidence interval [CI] 1.01-4.03, p = 0.046) and functional improvement (adjusted common OR 2.06, 95% CI 1.18-3.60, p = 0.011) and lower likelihood of 90-day mortality (11% vs 23%, aOR 0.20, 95% CI 0.07-0.58, p = 0.003). No differences in any other outcomes were detected. In subgroup analyses, patients with BT with baseline NIHSS scores <15 had higher functional independence likelihood compared to those with dEVT (aOR 4.87, 95% CI 1.56-15.18, p = 0.006); this association was not evident for patients with NIHSS scores ≥15 (aOR 1.05, 95% CI 0.40-2.74, p = 0.92). Similarly, functional outcomes improvements with BT were detected in patients with core volume strata (ischemic core <50 cm3: aOR 2.10, 95% CI 1.02-4.33, p = 0.044 vs ischemic core ≥50 cm3: aOR 0.41, 95% CI 0.01-16.02, p = 0.64) and transfer status (transferred: aOR 2.21, 95% CI 0.93-9.65, p = 0.29 vs direct to EVT center: aOR 1.84, 95% CI 0.80-4.23, p = 0.15).

CONCLUSIONS

BT appears to be associated with better clinical outcomes, especially with milder NIHSS scores, smaller presentation core volumes, and those who were "dripped and shipped." We did not observe any potential benefit of BT in patients with more severe strokes.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT02446587.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for patients with ischemic stroke from anterior circulation LVO within 4.5 hours from last known well, BT compared to dEVT leads to better 90-day functional outcomes.

Functional Outcome After Mechanical Thrombectomy with or without Previous Thrombolysis

INTRODUCTION

Combined intravenous therapy (IVT) and mechanical thrombectomy (MT) is the standard treatment for acute ischemic stroke (AIS) with large vessel occlusion (LVO). However, the use of  IVT before MT is recently being questioned.

OBJECTIVES

To compare patients treated with IVT before MT with those treated with MT alone, in a real-world scenario.

METHODS

Retrospective analysis of AIS patients with LVO of the anterior circulation who underwent MT, with or without previous IVT, between 2016 and 2018.

RESULTS

A total of 524 patients were included (347 submitted to IVT+MT; 177 to MT alone). No differences between groups were found except for a higher time from stroke onset to CT and to groin puncture in the MT group (297.5 min vs 115.0 min and 394.0 min vs 250.0 min respectively, p < 0.001). Multivariable analysis showed that age<75 years (OR 2.65, 95% CI 1.71-4.07, p < 0.001), not using antiplatelet therapy (OR 1.93, 95% CI 1.21-3.08, p = 0.006), low prestroke mRS (OR 4.33, 95% CI 1.89-9.89, p < 0.001), initial NIHSS (OR 0.89, 95% CI 0.86-0.93, p < 0.001), absent cerebral edema (OR 7.83, 95% CI 3.31-18.51, p < 0.001), and mTICI 2b/3 (OR 4.56, 95% CI 2.17-9.59, p < 0.001) were independently associated with good outcome (mRS 0-2).

CONCLUSIONS

Our findings support the idea that IVT before MT does not influence prognosis, in a real-world setting.

Intravenous r-tPA Dose Influence on Outcome after Middle Cerebral Artery Ischemic Stroke Treatment by Mechanical Thrombectomy

Background and Objectives: Pretreatment with intravenous thrombolysis (IVT) is still recommended in all eligible acute ischemic stroke patients with large-vessel occlusion before mechanical thrombectomy (MTE). However, the added value and safety of bridging therapy versus direct MTE remains controversial. We aimed at evaluating the influence of r-tPA dose level in patients with middle cerebral artery (MCA) occlusion treated with MTE. Materials and Methods: We prospectively compared clinical and radiological outcomes in 38 bridging patients, with 65 receiving direct MTE for MCA stroke admitted to Vilnius University Hospital Santaros Clinics. Following our protocol, r-tPA infusion was stopped just before MTE in the operating room. Therefore, we divided all bridging patients into three groups according to the amount of r-tPA they received: bolus, partial dose or full dose. Functional independence at 90 days was assessed by a modified Rankin Scale score, i.e., from 0–2. The safety outcomes included 90-day mortality and any intracerebral hemorrhage (ICH). Results: Baseline characteristics and functional outcome at 90 days did not differ between the bridging and direct MTE groups. Shorter MTE procedure and hospitalization time (p = 0.025 and p = 0.036, respectively) were observed in the direct MTE group. An IVT treatment subgroup analysis showed higher rates of symptomatic ICH (p < 0.001) and longer intervals between imaging to MTE (p = 0.005) in the full r-tPA dose group. Conclusions: In patients with an MCA stroke, direct MTE seems to be a safe and equally effective as bridging therapy. The optimal r-tPA dose remains unclear. Randomized trials are needed to accurately evaluate the added value of r-tPA in patients treated with MTE.

Intravenous thrombolysis prior to mechanical thrombectomy in large vessel occlusions

OBJECTIVE

The substantial clinical improvement in acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT), combined with the poor response of proximal intracranial occlusions to intravenous thrombolysis (IVT), led to questions regarding the utility of bridging therapy (BT; IVT followed by MT) compared to direct mechanical thrombectomy (dMT) for AIS patients with large vessel occlusion (LVO).

METHODS

We aimed to investigate the comparative safety and efficacy of BT and dMT in AIS patients. We included all observational studies and post hoc analyses from randomized controlled clinical trials that provided data on the outcomes of AIS patients with LVO stratified by IVT treatment status prior to MT.

RESULTS

We identified 38 eligible observational studies (11,798 LVO patients, mean age = 68 years, 56% treated with BT). In unadjusted analyses, BT was associated with a higher likelihood of 3-month functional independence (odds ratio [OR] = 1.52, 95% confidence interval [CI] = 1.32-1.76), 3-month functional improvement (common OR [cOR] for 1-point decrease in modified Rankin Scale score = 1.52, 95% CI = 1.18-1.97), early neurological improvement (OR = 1.21, 95% CI = 1.83-1.76), successful recanalization (OR = 1.22, 95% CI = 1.02-1.46), and successful recanalization with ≤2 device passes (OR = 2.28, 95% CI = 1.43-3.64) compared to dMT. BT was also related to a lower likelihood of 3-month mortality (OR = 0.64, 95% CI = 0.57-0.73). In the adjusted analyses, BT was independently associated with a higher likelihood of 3-month functional independence (adjusted OR = 1.55, 95% CI = 1.26-1.91) and lower odds of 3-month mortality (adjusted OR = 0.80, 95% CI = 0.66-0.97) compared to dMT. The two groups did not differ in functional improvement (adjusted cOR = 1.24, 95% CI = 0.89-1.74) or symptomatic intracranial hemorrhage (adjusted OR = 0.87, 95% CI = 0.61-1.25).

INTERPRETATION

BT appears to be associated with improved functional independence without evidence for safety concerns, compared to dMT, for AIS patients with LVO. ANN NEUROL 2019;86:395-406.

Intravenous thrombolysis pretreatment and other predictors of infarct in a new previously unaffected territory (INT) in ELVO strokes treated with mechanical thrombectomy

INTRODUCTION

One uncommon complication of mechanical thrombectomy (MT) is an infarct in a new previously unaffected territory (infarct in new territory (INT)).

OBJECTIVE

To evaluate the predictors of INT with special focus on intravenous thrombolysis(IVT)pretreatmentbefore MT.

METHODS

Consecutive patients with emergent large vessel occlusion (ELVO) treated with MT during a 5-year period were evaluated. INT was defined using standardized methodology proposed by ESCAPE investigators. The predictors of INT and its impact on outcomes were investigated.

RESULTS

A total of 419 consecutive patients with ELVO received MT (mean age 64±15 years, 50% men, median baseline National Institutes of Health Stroke Scale score 16 points (IQR 11-20), 69% pretreated with IVT). The incidence of INT was lower in patients treated with combination therapy (IVTandMT) than in patients treated with MT alone, respectively (10% vs 20%; p=0.011). The INT group had more patients with posterior circulation occlusions than the group without INT (28% vs 10%, respectively; p<0.001). The rates of 3-month functional independence were lower in patients with INT (30% vs 50%; p=0.007). IVT pretreatment was not independently related to INT (OR=0.75; 95% CI 0.32 to 1.76), and INT did not emerge as an independent predictor of 3-month functional independence (OR=0.69; 95% CI 0.29 to 1.62) on multivariable logistic regression models. Location of posterior circulation occlusion was independently associated with a higher odds of INT (OR=3.33; 95% CI 1.43 to 7.69; p=0.005).

CONCLUSIONS

IVT pretreatment is not independently associated with a lower likelihood of INT in patients with ELVO treated with MT. Patients with ELVO with posterior circulation occlusion are more likely to have INT after MT.

Impact of pretreatment with intravenous thrombolysis on reperfusion status in acute strokes treated with mechanical thrombectomy

Introduction

We sought to evaluate the impact of pretreatment with intravenous thrombolysis (IVT) on the rate and speed of successful reperfusion (SR) in patients with emergent large vessel occlusion (ELVO) treated with mechanical thrombectomy (MT) in a high-volume tertiary care stroke center.

Methods

Consecutive patients with ELVO treated with MT were evaluated. Outcomes were compared between patients who underwent combined IVT and MT (IVT+MT) and those treated with direct MT (dMT). The elapsed time between groin puncture to beginning of reperfusion (GPTBRT) and the numbers of device passes required to achieve SR were also documented.

Results

A total of 287 and 132 patients were treated with IVT+MT and dMT, respectively. The IVT+MT group had higher SR (73.8% vs 62.9%; p=0.023) and 3-month functional independence (modified Rankin Scale score 0–2;51.6% vs 38.2%; p=0.008) rates. The median GPTBRT was shorter in the IVT+MT group (48 (IQR 33–70) vs 70 (IQR 44–98) min; p<0.001). Among patients who achieved SR (n=292), the median number of required device passes was lower in the IVT+MT subgroup (1 (IQR 1–1) vs 2 (IQR 1–2); p<0.001), while the rate of patients requiring ≤2 device passes was higher (98% vs 77%; p<0.001). IVT+MT was independently related to higher odds of SR (OR 1.64; 95% CI 1.03 to 2.61; p=0.036) and shorter GPTBRT (unstandardized linear regression coefficient −20.39; 95% CI −27.56 to –13.22; p<0.001) on multivariable analyses adjusting for potential confounders. Among patients with SR, IVT+MT was independently associated with a higher likelihood of ≤2 device passes (OR 14.63; 95% CI 4.46 to 48.00; p<0.001).

Conclusions

IVT pretreatment appears to increase the rates of SR and shortens the duration of the endovascular procedure by requiring fewer device passes in patients with ELVO treated with MT.

Direct mechanical thrombectomy in tPA-ineligible and -eligible patients versus the bridging approach: a meta-analysis

BACKGROUND

Whether pretreatment with intravenous thrombolysis prior to mechanical thrombectomy (IVT+MTE) adds additional benefit over direct mechanical thrombectomy (dMTE) in patients with large vessel occlusions (LVO) is a matter of debate.

METHODS

This study-level meta-analysis was presented in accord with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Pooled effect sizes were calculated using the inverse variance heterogeneity model and displayed as summary Odds Ratio (sOR) and corresponding 95% confidence interval (95% CI). Sensitivity analysis was performed by distinguishing between studies including dMTE patients eligible for IVT (IVT-E) or ineligible for IVT (IVT-IN). Primary outcome measures were functional independence (modified Rankin Scale≤2) and mortality at day 90, successful reperfusion, and symptomatic intracerebral hemorrhage.

RESULTS

Twenty studies, incorporating 5279 patients, were included. There was no evidence that rates of successful reperfusion differed in dMTE and IVT+MTE patients (sOR 0.93, 95% CI 0.68 to 1.28). In studies including IVT-IN dMTE patients, patients undergoing dMTE tended to have lower rates of functional independence and had higher odds for a fatal outcome as compared with IVT+MTE patients (sOR 0.78, 95% CI 0.61 to 1.01 and sOR 1.45, 95% CI 1.22 to 1.73). However, no such treatment group effect was found when analyses were confined to cohorts with a lower risk of selection bias (including IVT-E dMTE patients).

CONCLUSION

The quality of evidence regarding the relative merits of IVT+MTE versus dMTE is low. When considering studies with lower selection bias, the data suggest that dMTE may offer comparable safety and efficacy as compared with IVT+MTE. The conduct of randomized-controlled clinical trials seems justified.

Multivessel Occlusion in Patients Subjected to Thrombectomy: Prevalence, Associated Factors, and Clinical Implications

BACKGROUND AND PURPOSE

Patients with embolic large-vessel occlusion may present with additional coincidental acute occlusions within or distant from the involved territory, referred to as multivessel occlusion (MVO). Purpose of this study was to assess prevalence of MVO, associated factors, and clinical relevance in patients undergoing endovascular stroke treatment.

METHODS

Image data of consecutive endovascular candidates (n=720) with direct access to angiography were extracted from a prospective registry. Prevalence of MVO was assessed with multimodal magnetic resonance imaging/computed tomography and confirmed by intra-arterial angiography. Explorative analysis of associated factors and clinical relevance was evaluated using multivariable logistic regression including variables with P<0.15 in univariate comparison. Good functional outcome was defined as modified Rankin Scale score ≤2 at day 90.

RESULTS

MVO was present in 10.7% of patients (95% confidence interval [CI], 6.4%-13.0%). Two, 3, and 4 concomitant occlusions were found in 80.5%, 16.9%, and 2.6% of MVO cases, respectively. Detection rate on initial radiological report was 54.5%. Downstream MVO was present in around one third of MVO (n=27/77, 35.1%), whereas all other MVO (n=50/77, 64.9%) occurred in different territories. Independent factors related to MVO were statin treatment (adjusted odds ratio [aOR], 0.477; 95% CI, 0.276-0.827), higher systolic blood pressure (aOR per mm Hg increase, 1.014; 95% CI, 1.005-1.023), and primary occlusion site M2 (aOR, 1.870; 95% CI, 1.103-3.170). MVO was related to lower rates of successful reperfusion (aOR, 0.549; 95% CI, 0.316-0.953) and lower rates of good functional outcome (aOR, 0.437; 95% CI, 0.207-0.923).

CONCLUSIONS

Every tenth patient subjected to angiography for endovascular stroke treatment experienced MVO in our series, and only half were prospectively identified on preinterventional diagnostic imaging. Patients with MVO had higher baseline systolic blood pressure and were less often medicated with statins, an observation that warrants external validation and evaluation regarding causality. Occurrence of MVO has implication for treatment decisions, negatively affects endovascular treatment success, and is predictive of worse clinical outcome.