Endovascular thrombectomy with or without systemic thrombolysis?

High Hypoperfusion Intensity Ratio Is Independently Associated with Very Poor Outcomes in Large Ischemic Core Stroke

BACKGROUND

Recent advances have highlighted the efficacy of endovascular thrombectomy (EVT) in patients with large ischemic core stroke, yet a significant portion still experience very poor outcomes, defined as a 90-day modified Rankin Score (mRS) of 5-6. This study aims to investigate the hypoperfusion intensity ratio (HIR) as a prognostic imaging parameter for these outcomes.

METHODS

In a multicenter retrospective cohort study, data from consecutive patients undergoing EVT for acute ischemic stroke with large vessel occlusion (AIS-LVO) at two comprehensive stroke centers were analyzed. The study included patients with an Alberta Stroke Program Early CT Score (ASPECTS) of 5 or less and utilized pretreatment perfusion imaging to calculate HIR. The primary outcome was very poor outcomes (90 days mRS 5-6).

RESULTS

Among 102 patients included, 59 (57.8%) had very poor outcome (90 days mRS 5-6). Multivariable logistic regression analysis adjusting for multiple covariates including admission National Institutes of Health Stroke Scale (NIHSS) and EVT revealed that higher admission NIHSS (adjusted odds ratio [aOR] 1.224, 95% CI 1.089-1.374, p = 0.001) and HIR (aOR per 0.1 incremental change, 1.34, 95% CI 1.02-1.82, P = 0.042) were independently associated with very poor outcomes.

CONCLUSION

This study demonstrates that admission NIHSS and HIR are independently associated with very poor outcome (90 days mRS 5-6) in patients with large ischemic core strokes. These findings highlight the importance of collateral status and perfusion imaging in predicting outcomes in this patient population, suggesting a potential role for HIR in the triage and management of large core stroke patients.

Pretreatment predictors of very poor clinical outcomes in medium vessel occlusion stroke patients treated with mechanical thrombectomy

BACKGROUND

Acute ischemic stroke (AIS) from primary medium vessel occlusions (MeVO) is a prevalent condition associated with substantial morbidity and mortality. Despite the common use of mechanical thrombectomy (MT) in AIS, predictors of poor outcomes in MeVO remain poorly characterized.

METHODS

In this prospectively collected, retrospectively reviewed, multicenter, multinational study, data from the MAD-MT (Multicenter Analysis of primary Distal medium vessel occlusions: effect of Mechanical Thrombectomy) registry were analyzed. The study included 1568 patients from 37 academic centers across North America, Asia, and Europe, treated with MT, with or without intravenous tissue plasminogen activator (IVtPA), between September 2017 and July 2021.

RESULTS

Among the 1568 patients, 347 (22.2%) experienced very poor outcomes (modified Rankin score (mRS), 5-6). Key predictors of poor outcomes were advanced age (odds ratio (OR): 1.03; 95% confidence interval (CI): 1.02 to 1.04; p < 0.001), higher baseline National Institutes of Health Stroke Scale (NIHSS) scores (OR: 1.07; 95% CI: 1.05 to 1.10; p < 0.001), pre-operative glucose levels (OR: 1.01; 95% CI: 1.00 to 1.02; p < 0.001), and a baseline mRS of 4 (OR: 2.69; 95% CI: 1.25 to 5.82; p = 0.011). The multivariable model demonstrated good predictive accuracy with an area under the receiver-operating characteristic (ROC) curve of 0.76.

CONCLUSIONS

This study demonstrates that advanced age, higher NIHSS scores, elevated pre-stroke mRS, and pre-operative glucose levels significantly predict very poor outcomes in AIS-MeVO patients who received MT. These findings highlight the importance of a comprehensive risk assessment in primary MeVO patients for personalized treatment strategies. However, they also suggest a need for cautious patient selection for endovascular thrombectomy. Further prospective studies are needed to confirm these findings and explore targeted therapeutic interventions.

Endovascular thrombectomy without versus with different pre-intravenous thrombolysis in acute ischemic stroke: a network meta-analysis of randomized controlled trials

Background

The current guideline recommended the use of intravenous thrombolysis (IVT) before Endovascular thrombectomy (EVT), but the effectiveness and safety of tenecteplase compare to alteplase in patients before EVT remain uncertain.

Methods

We searched PubMed, Embase, Web of Science, and the Cochrane Library to identify eligible articles from inception until September 16, 2023. The primary outcome was functional independence (mRS 0-2) at 90 days. Secondary outcomes included excellent outcome (mRS 0-1) at 90 days, all-cause mortality at follow-up, successful reperfusion (TICI 2b-3) after the end of EVT, symptomatic intracranial hemorrhage (sICH) or any intracranial hemorrhage (aICH). The PROSPERO registration number is CRD42023470419.

Results

Eight randomized controlled trials (RCTs) were included involving 2,836 acute ischemic stroke (AIS) patients. Compared to EVT alone, tenecteplase (0.25 mg/kg and 0.4 mg/kg) + EVT and 0.9 mg/kg alteplase + EVT were significant difference associated with higher successful reperfusion (TICI 2b-3) after the end of EVT (RR = 2.31; 95% CI 1.15-4.63; RR = 2.31; 95% CI 1.00-5.33; RR = 1.05; 95% CI 1.01-1.09). And compared to 0.25 mg/kg tenecteplase + EVT, alteplase (0.6 mg/kg and 0.9 mg/kg) + EVT were significant difference associated with lower successful reperfusion (TICI 2b-3) after the end of EVT (RR = 0.45; 95% CI 0.22-0.90; RR = 0.45; 95% CI 0.23-0.91). The risk of aICH (RR = 1.50; 95% CI 1.07-2.09) was significantly higher for 0.6 mg/kg alteplase + EVT than EVT alone. There was no significant difference in functional independence (mRS 0-2), excellent outcome (mRS 0-1), all-cause mortality or sICH among the different IVT strategies (0.25 mg/kg or 0.4 mg/kg tenecteplase and 0.6 mg/kg or 0.9 mg/kg alteplase) before EVT.

Conclusion

The use of alteplase before EVT may potentially improve the successful reperfusion after EVT compared to tenecteplase. Due to the insufficient sample size, more high-quality RCTs are needed to confirm effectiveness and safety of tenecteplase compare to alteplase in patients before EVT.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42023470419.

Endovascular Thrombectomy With or Without Thrombolysis for Stroke: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

To this date, whether to administer intravenous thrombolysis (IVT) prior to endovascular thrombectomy (EVT) for stroke patients still stirs some debate. We aimed to systematically update the evidence from randomized trials comparing EVT alone vs EVT with bridging IVT.

Methods

We searched MEDLINE, EMBASE, and the Cochrane Library to identify randomized controlled trials (RCTs) comparing EVT with or without IVT in patients presenting with stroke secondary to a large vessel occlusion. We conducted meta-analyses using random-effects models to compare functional independence, mortality, and symptomatic intracranial hemorrhage (sICH), between EVT and EVT with IVT. We assessed risk of bias using the Cochrane risk-of-bias tool and certainty of evidence for each outcome using the GRADE approach.

Results

Of 11,111 citations, we included 6 studies with a total of 2336 participants. We found low-certainty evidence of possibly a small decrease in the proportion of patients with functional independence (risk difference [RD] -2.0%, 95% CI -5.9% to 2.0%), low-certainty evidence that there is possibly a small increase in mortality (RD 1.0%, 95% CI -2.2% to 4.7%), and moderate-certainty evidence that there is probably a decrease in sICH (RD -1.0%, 95% CI -1.6% to .7%) for patients with EVT alone compared to EVT plus IVT, respectively.

Conclusion

Low-certainty evidence shows that there is possibly a small decrease in functional independence, low-certainty evidence shows that there is possibly a small increase in mortality, and moderate-certainty evidence that there is probably a decrease in sICH for patients with EVT alone compared to EVT plus IVT.

Endovascular thrombectomy with or without thrombolysis bridging in patients with acute ischaemic stroke: protocol for a systematic review, meta-analysis of randomised trials and cost-effectiveness analysis

INTRODUCTION

Current published guidelines and meta-analyses comparing endovascular thrombectomy (EVT) alone versus EVT with bridging intravenous thrombolysis (IVT) suggest that EVT alone is non-inferior to EVT with bridging thrombolysis in achieving favourable functional outcome. Because of this controversy, we aimed to systematically update the evidence and meta-analyse data from randomised trials comparing EVT alone versus EVT with bridging thrombolysis, and performed an economic evaluation comparing both strategies.

METHODS AND ANALYSIS

We will conduct a systematic review of randomised controlled trials comparing EVT with or without bridging thrombolysis in patients presenting with large vessel occlusions. We will identify eligible studies by systematically searching the following databases from inception without any language restrictions: MEDLINE (through Ovid), Embase and the Cochrane Library. The following criteria will be used to assess eligibility for inclusion: (1) adult patients ≥18 years old; (2) randomised patients to EVT alone or to EVT with IVT; and (3) measured outcomes, including functional outcomes, at least 90 days after randomisation. Pairs of reviewers will independently screen the identified articles, extract information and assess the risk of bias of eligible studies. We will use the Cochrane Risk-of-Bias tool to evaluate risk of bias. We will also use the Grading of Recommendations, Assessment, Development and Evaluation approach to assess the certainty in evidence for each outcome. We will then perform an economic evaluation based on the extracted data.

ETHICS AND DISSEMINATION

This systematic review will not require a research ethics approval because no confidential patient data will be used. We will disseminate our findings by publishing the results in a peer-reviewed journal and via presentation at conferences.

PROSPERO REGISTRATION NUMBER

CRD42022315608.

Intravenous thrombolysis before thrombectomy in acute ischemic stroke: a dual centre retrospective cohort study

First pass effect (FPE) is a successful recanalization (mTICI ≥ 2b) after the first trial of thrombectomy. It is associated with good functional outcomes. Few studies discussed the effect of BT (bridging therapy: combined I.V. thrombolysis and mechanical thrombectomy) on FPE and clinical outcomes. In our study, we would like to report the effect of MT with or without preceding IVT on FPE and the functional outcome of AIS (Acute Ischemic Stroke) of anterior circulation in real practice. A dual-center retrospective cohort study enrolled 201 patients with AIS of anterior circulation and was divided into a bridging therapy (BT) group of 150 patients who received alteplase preceding thrombectomy, and a direct mechanical thrombectomy (dMT) group of 51 patients. Comparisons between both groups regarding the clinical and radiological outcome. Early better clinical outcome (mRS ≤ 2) at day seven with BT group (39.3%) rather than dMT (23.5%) with P value = 0.044. No significant differences as regard puncture to revascularization time, successful revascularization (mTICI) ≥ 2b and FPE between both groups (P value: 0.328, 0.538, and 0.708, respectively). No differences as regards hemorrhagic transformation, mortality rate, and 90-day favorable outcome between both groups (P value 0.091, 0.089, and 0.192, respectively). BT might have better early outcome than dMT but no difference as regards 90-day favorable outcomes, mortality, sICH, FPE, recanalization rate and procedure time. It might be reasonable to go directly to mechanical thrombectomy without IVT for AIS with large vessel occlusion.

Intravenous Thrombolysis Before Mechanical Thrombectomy for Acute Ischemic Stroke: A Meta-Analysis

Background

Whether intravenous thrombolysis before mechanical thrombectomy provides additional benefit for functional outcome in acute ischemic stroke remains uncertain. We performed a meta‐analysis to compare the outcomes of direct mechanical thrombectomy (dMT) to mechanical thrombectomy with bridging using intravenous thrombolysis (bridging therapy [BT]) in patients with acute ischemic stroke.

Methods and Results

We performed a literature search in the PubMed, Excerpta Medica database, and Cochrane Central Register of Controlled Trials from January 1, 2003, to April 26, 2021. We included randomized clinical trials and observational studies that reported the 90‐day functional outcome in patients with acute ischemic stroke undergoing dMT compared with BT. The 12 included studies (3 randomized controlled trials and 9 observational studies) yielded 3924 participants (mean age, 68.0 years [SD, 13.1 years]; women, 44.2%; 1887 participants who received dMT and 2037 participants who received BT). A meta‐analysis of randomized controlled trial and observational data revealed similar 90‐day functional independence (odds ratio [OR], 1.04; 95% CI, 0.90–1.19), mortality (OR, 1.03; 95% CI, 0.78–1.36), and successful recanalization (OR, 0.93; 95% CI, 0.76–1.14) for patients treated with dMT or BT. Compared with those in the BT group, patients in the dMT group were less likely to experience symptomatic intracranial hemorrhage (OR, 0.68; 95% CI, 0.51–0.91; P=0.008) or any intracranial hemorrhage (OR, 0.71; 95% CI, 0.61–0.84; P<0.001).

Conclusions

In this meta‐analysis of patients with acute ischemic stroke, we found no significant differences in 90‐day functional outcome or mortality between dMT and BT, but a lower rate of symptomatic intracranial hemorrhage for dMT. These findings support the use of dMT without intravenous thrombolysis bridging therapy.

Registration

URL: https://www.crd.york.ac.uk/prospero/; Unique identifier: 42021234664.

'Drip-and-ship' intravenous thrombolysis and outcomes for large vessel occlusion thrombectomy candidates in a hub-and-spoke telestroke model

BACKGROUND

Randomized trials have not demonstrated benefit from intravenous thrombolysis among patients undergoing endovascular thrombectomy (EVT). However, these trials included primarily patients presenting directly to an EVT capable hub center. We sought to study outcomes for EVT candidates who presented to spoke hospitals and were subsequently transferred for EVT consideration, comparing those administered alteplase at spokes (i.e., 'drip-and-ship' model) versus those not.

METHODS

Consecutive EVT candidates presenting to 25 spokes from 2018 to 2020 with pre-transfer CT angiography defined emergent large vessel occlusion and Alberta Stroke Program CT score ≥6 were identified from a prospectively maintained Telestroke database. Outcomes of interest included adequate reperfusion (Thrombolysis in Cerebral Infarction (TICI) 2b-3), intracerebral hemorrhage (ICH), discharge functional independence (modified Rankin Scale (mRS) ≤2), and 90 day functional independence.

RESULTS

Among 258 patients, median age was 70 years (IQR 60-81), median National Institutes of Health Stroke Scale (NIHSS) score was 13 (6-19), and 50% were women. Ninety-eight (38%) were treated with alteplase at spokes and 113 (44%) underwent EVT at the hub. Spoke alteplase use independently increased the odds of discharge mRS ≤2 (adjusted OR 2.43, 95% CI 1.08 to 5.46, p=0.03) and 90 day mRS ≤2 (adjusted OR 3.45, 95% CI 1.65 to 7.22, p=0.001), even when controlling for last known well, NIHSS, and EVT; it was not associated with an increased risk of ICH (OR 1.04, 95% CI 0.39 to 2.78, p=0.94), and there was a trend toward association with greater TICI 2b-3 (OR 3.59, 95% CI 0.94 to 13.70, p=0.06).

CONCLUSIONS

Intravenous alteplase at spoke hospitals may improve discharge and 90 day mRS and should not be withheld from EVT eligible patients who first present at alteplase capable spoke hospitals that do not perform EVT. Additional studies are warranted to confirm and further explore these benefits.

Efficacy and safety of bridging thrombolysis initiated before transfer in a drip-and-ship stroke service

Objective

Data regarding the efficacy and safety of bridging thrombolysis (BT) initiated before transfer for evaluation of endovascular therapy is heterogeneous. We, therefore, analyse efficacy and safety of BT in patients treated within a drip-and-ship stroke service.

Methods

Consecutive adult patients suffering from acute ischaemic stroke and large-vessel occlusions (LVO) transferred to our comprehensive stroke centre for evaluation of endovascular therapy in 2017–2020 were identified from a local prospective stroke database and categorised according to BT and no-BT. BT was defined as intravenous thrombolysis initiated before transfer. LVO was assessed before and after transfer. Functional outcome before stroke and at 3 months using the modified Rankin scale (mRS) was determined. Excellent outcome was defined as mRS 0–1 or return to prestroke mRS. For safety analysis, intracranial haemorrhages and mortality at 3 months were analysed. Main analysis was limited to patients with anterior circulation stroke.

Results

Of N=714 patients, n=394 (55.2%) received BT. More patients in the BT group with documented LVO before transfer recanalised without endovascular therapy (n=46, 11.7%) than patients who did not receive BT before transfer (n=4, 1.3%, p<0.001). In multivariate analysis, BT was the strongest independent predictor of early recanalisation (adjusted OR 10.9, 95% CI 3.8 to 31.1, p<0.001). BT tended to be an independent predictor of an excellent outcome at 3 months (adjusted OR 1.38, 95% CI 0.97 to 1.96, p=0.077). There were no differences in safety between the BT and no-BT groups.

Conclusions

BT initiated before transfer was a strong independent predictor of early recanalisation.

Comparison of Prior Bridging Intravenous Thrombolysis With Direct Endovascular Thrombectomy for Anterior Circulation Large Vessel Occlusion: Systematic Review and Meta-Analysis

Background: Whether bridging treatment combining intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT) is superior to direct EVT alone for emergent large vessel occlusion (LVO) in the anterior circulation is unknown. A systematic review and a meta-analysis were performed to investigate and assess the effect and safety of bridging treatment vs. direct EVT in patients with LVO in the anterior circulation.

Methods: PubMed, EMBASE, and the Cochrane library were searched to assess the effect and safety of bridging treatment and direct EVT in LVO. Functional independence, mortality, asymptomatic and symptomatic intracranial hemorrhage (aICH and sICH, respectively), and successful recanalization were evaluated. The risk ratio and the 95% CI were analyzed.

Results: Among the eight studies included, there was no significant difference in the long-term functional independence (OR = 1.008, 95% CI = 0.845–1.204, P = 0.926), mortality (OR = 1.060, 95% CI = 0.840–1.336, P = 0.624), recanalization rate (OR = 1.015, 95% CI = 0.793–1.300, P = 0.905), and the incidence of sICH (OR = 1.320, 95% CI = 0.931–1.870, P = 0.119) between bridging therapy and direct EVT. After adjusting for confounding factors, bridging therapy showed a lower recanalization rate (effect size or ES = −0.377, 95% CI = −0.684 to −0.070, P = 0.016), but there was no significant difference in the long-term functional independence (ES = 0.057, 95% CI = −0.177 to 0.291, P = 0.634), mortality (ES = 0.693, 95% CI = −0.133 to 1.519, P = 0.100), and incidence of sICH (ES = −0.051, 95% CI = −0.687 to 0.585, P = 0.875) compared with direct EVT. Meanwhile, in the subgroup analysis of RCT, no significant difference was found in the long-term functional independence (OR = 0.927, 95% CI = 0.727–1.182, P = 0.539), recanalization rate (OR = 1.331, 95% CI = 0.948–1.867, P = 0.099), mortality (OR = 1.072, 95% CI = 0.776–1.481, P = 0.673), and sICH incidence (OR = 1.383, 95% CI = 0.806–2.374, P = 0.977) between patients receiving bridging therapy and those receiving direct DVT.

Conclusion: For stroke patients with acute anterior circulation occlusion and who are eligible for intravenous thrombolysis, there is no significant difference in the clinical effect between direct EVT and bridging therapy, which needs to be verified by more randomized controlled trials.

Drip-and-ship versus mothership for endovascular treatment of acute stroke: A comparative effectiveness analysis

BACKGROUND

Triage for suspected acute stroke has two main options: (1) transport to the closest primary stroke center (PSC) and then to the nearest comprehensive stroke center (CSC) (Drip-and-Ship) or (2) transport the patient to the nearest CSC, bypassing a closer PSC (mothership). The purpose was to evaluate the effectiveness of drip-and-ship versus mothership models for acute stroke patients.

METHODS

A Markov decision-analytic model was constructed. All model parameters were derived from recent medical literature. Our target population was adult patient with sudden onset of acute stroke within 8 h of onset over a one-year horizon. The primary outcome was quantified in terms of quality-adjusted-life-years (QALYs).

RESULTS

The base case scenario show that the drip-and-ship strategy has a slightly higher expected health benefit, 0.591 QALY, as compared to 0.586 QALY in the mothership strategy when the time to PSC is 30 min and to CSC is 65 min, although the difference in health benefit becomes minimal as the time to PSC increases towards 60 min. Multiple sensitivity analyses show that when both PSC and CSC are far from place of onset (>1.5 h away), drip-and-ship becomes the better strategy. Mothership strategy is favored by smaller difference between distances to PSC and CSC, shorter transfer time from PSC to CSC, and longer delay in reperfusion in CSC for transferred patients. Drip-and-ship is favored by the reverse.

CONCLUSION

Drip-and-ship has a slightly higher utility than mothership. This study assesses the complex issue of prehospital triage of acute stroke patients and can provide a framework for real-world data input.

The benefit of intravenous thrombolysis prior to mechanical thrombectomy within the therapeutic window for acute ischemic stroke

The increase in risk for acute ischemic stroke (AIS) with age is well established. If not treated properly and promptly, AIS can result in permanent neurological damage and even death. This literature review assesses the clinical outcomes of AIS patients treated with both intravenous thrombolysis (IVT) prior to mechanical thrombectomy (MT) compared to those treated solely with mechanical thrombectomy. Randomized controlled trials (RCTs) and meta-analyses published from 2015 to 2020 and available on PubMed were selected for review, and their quantitative and qualitative findings were extrapolated and summarized. Post-hoc analyses from ASTER and ETIS trials were reviewed as well as the impact of combined therapy and monotherapy on large vessel occlusions (LVO). Clinical outcomes in all examined trials demonstrated significant successful reperfusion as well as a higher rate of functional independence at 90 days for IVT prior to MT. Concerns of thrombus fragility, safety and cost effectiveness of dual therapy are also addressed. Based on these findings, we recommend the use of IVT as a pretreatment procedure to MT for AIS when eligible for IVT. Recent articles further strengthen this recommendation and provide new insights that IVT prior to MT is especially beneficial for patients presenting with multiple LVOs localized to the anterior intracranial circulation. Additional multi-center RCTs are necessary for further analysis of statistical outcomes demonstrating mixed effects.

Thrombus Migration and Fragmentation After Intravenous Alteplase Treatment: The INTERRSeCT Study

BACKGROUND AND PURPOSE

There is interest in what happens over time to the thrombus after intravenous alteplase. We study the effect of alteplase on thrombus structure and its impact on clinical outcome in patients with acute stroke.

METHODS

Intravenous alteplase treated stroke patients with intracranial internal carotid artery or middle cerebral artery occlusion identified on baseline computed tomography angiography and with follow-up vascular imaging (computed tomography angiography or first run of angiography before endovascular therapy) were enrolled from INTERRSeCT study (Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography). Thrombus movement after intravenous alteplase was classified into complete recanalization, thrombus migration, thrombus fragmentation, and no change. Thrombus migration was diagnosed when occlusion site moved distally and graded according to degrees of thrombus movement (grade 0-3). Thrombus fragmentation was diagnosed when a new distal occlusion in addition to the primary occlusion was identified on follow-up imaging. The association between thrombus movement and clinical outcome was also evaluated.

RESULTS

Among 427 patients in this study, thrombus movement was seen in 54% with a median time of 123 minutes from alteplase administration to follow-up imaging, and sub-classified as marked (thrombus migration grade 2-3 + complete recanalization; 27%) and mild to moderate thrombus movement (thrombus fragmentation + thrombus migration grade 0-1; 27%). In patients with proximal M1/internal carotid artery occlusion, marked thrombus movement was associated with a higher rate of good outcome (90-day modified Rankin Scale, 0-2) compared with mild to moderate movement (52% versus 27%; adjusted odds ratio, 5.64 [95% CI, 1.72-20.10]). No difference was seen in outcomes between mild to moderate thrombus movement and no change. In M1 distal/M2 occlusion, marked thrombus movement was associated with improved 90-day good outcome compared with no change (70% versus 56%; adjusted odds ratio, 2.54 [95% CI, 1.21-5.51]).

CONCLUSIONS

Early thrombus movement is common after intravenous alteplase. Marked thrombus migration leads to good clinical outcomes. Thrombus dynamics over time should be further evaluated in clinical trials of acute reperfusion therapy.

Effect of atrial fibrillation on endovascular thrombectomy for acute ischemic stroke. A meta-analysis of individual patient data from six randomised trials: Results from the HERMES collaboration

Background

Atrial fibrillation is an important risk factor for ischemic stroke, and is associated with an increased risk of poor outcome after ischemic stroke. Endovascular thrombectomy is safe and effective in acute ischemic stroke patients with large vessel occlusion of the anterior circulation. This meta-analysis aims to investigate whether there is an interaction between atrial fibrillation and treatment effect of endovascular thrombectomy, and secondarily whether atrial fibrillation is associated with worse outcome in patients with ischemic stroke due to large vessel occlusion.

Methods

Individual patient data were from six of the recent randomised clinical trials (MR CLEAN, EXTEND-IA, REVASCAT, SWIFT PRIME, ESCAPE, PISTE) in which endovascular thrombectomy plus standard care was compared to standard care alone. Primary outcome measure was the shift on the modified Rankin scale (mRS) at 90 days. Secondary outcomes were functional independence (mRS 0–2) at 90 days, National Institutes of Health Stroke Scale score at 24 h, symptomatic intracranial hemorrhage and mortality at 90 days. The primary effect parameter was the adjusted common odds ratio, estimated with ordinal logistic regression (shift analysis); treatment effect modification of atrial fibrillation was assessed with a multiplicative interaction term.

Results

Among 1351 patients, 447 patients had atrial fibrillation, 224 of whom were treated with endovascular thrombectomy. We found no interaction of atrial fibrillation with treatment effect of endovascular thrombectomy for both primary (p-value for interaction: 0.58) and secondary outcomes. Regardless of treatment allocation, we found no difference in primary outcome (mRS at 90 days: aOR 1.11 (95% CI 0.89–1.38) and secondary outcomes between patients with and without atrial fibrillation.

Conclusion

We found no interaction of atrial fibrillation on treatment effect of endovascular thrombectomy, and no difference in outcome between large vessel occlusion stroke patients with and without atrial fibrillation.

Does the Addition of Non-Approved Inclusion and Exclusion Criteria for rtPA Impact Treatment Rates? Findings in Australia, the UK, and the USA

BACKGROUND

Strict criteria for recombinant tissue plasminogen activator (rtPA) eligibility are stipulated on licences for use in ischaemic stroke; however, practitioners may also add non-standard rtPA criteria. We examined eligibility criteria variation in 3 English-speaking countries including use of non-standard criteria, in relation to rtPA treatment rates.

METHODS

Surveys were mailed to 566 eligible hospitals in Australia (AUS), the UK, and the USA. Criteria were pre-classified as standard (approved indication and contraindications) or non-standard (approved warning or researcher "decoy"). Percentage for criterion selection was calculated/compared; linear regression was used to assess the association between use of non-standard criteria and rtPA treatment rates, and to identify factors associated with addition of non-standard criteria.

RESULTS

Response rates were 74% AUS, 65% UK, and 68% USA; mean rtPA treatment rates were 8.7% AUS, 12.7% UK, and 8.7% USA. Median percentage of non-standard inclusions was 33% (all 3 countries) and included National Institutes of Health Stroke Scale (NIHSS) scores > 4, computed tomography (CT) angiography documented occlusion, and favourable CT perfusion. Median percentage of non-standard exclusions was 25% AUS, 28% UK, and 60% USA, and included depressed consciousness, NIHSS > 25, and use of antihypertensive infusions. No AUS or UK sites selected 100% of standard exclusions.

CONCLUSIONS

Non-standard criteria for rtPA eligibility were evident in all three countries and could, in part, explain comparably low use of rtPA. Differences in the use of standard criteria may signify practitioner intolerance for those derived from original efficacy studies that are no longer relevant.

Recanalization of Emergent Large Intracranial Vessel Occlusion through Intravenous Thrombolysis: Frequency, Clinical Outcome, and Reperfusion Pattern

BACKGROUND

According to a recent meta-analysis, 1 out of 10 patients with emergent large intracranial vessel occlusion (ELVO) causing stroke have recanalization after intravenous thrombolysis (IVT) alone. However, rate, clinical outcome, and recanalization pattern of this phenomenon are poorly understood.

OBJECTIVES AND METHODS

Patients with ELVO recanalized only by IVT were analyzed, and frequency of recanalization, clinical outcome, safety variables, and reperfusion pattern were assessed. These patients were compared to a group of patients with ELVO who underwent endovascular thrombectomy with or without prior IVT.

RESULTS

Successful or sufficient recanalization after IVT alone occurred in 81 of 760 patients (10.6%) with ELVO who had been referred for endovascular thrombectomy. These 81 patients (group 1) were compared to a group of patients receiving endovascular thrombectomy with prior IVT (group 2) or without (group 3). A good clinical outcome at 90 days was seen in 61.7% of patients in group 1, 32.2% in group 2, and 34.5% in group 3 (p < 0.001). The 3 groups had no significant differences in intracranial hemorrhage. IVT was not independently associated with symptomatic intracranial hemorrhage, parenchymal hematoma, or subarachnoid hemorrhage. Mortality at 90 days was 9.9% in group 1, 20.7% in group 2, and 29.6% in group 3 (p < 0.001). After adjusting for all relevant variables, outcome and mortality differences were nonsignificant. No difference in the rate of successful reperfusion (modified treatment in cerebral ischemia [mTICI] 2b/3) was found. A reperfusion mTICI 3 was achieved in 18.5% in group 1, 60.7% in group 2, and 57.1% in group 3 (p < 0.001). Patients in group 1 had lower chance of achieving a complete recanalization (mTICI 3) compared to patients in group 2, OR 0.15 (95% CI 0.08-0.29) and in group 3, OR 0.17 (95% CI 0.09-0.32; p < 0.001).

CONCLUSIONS

Primary IVT in ELVO caused a recanalization rate of 10.6%, making endovascular treatment either unnecessary or impossible. Early recanalization of ELVO with only IVT is associated with a 61.7% independence rate at 90 days and similar successful reperfusion rates (mTICI2b/3) compared to ELVO treated with endovascular treatment, with or without previous IVT. However, recanalization only through IVT achieves a lower rate of mTICI 3 reperfusion when compared to endovascular treatment.

Is intravenous thrombolysis still necessary in patients who undergo mechanical thrombectomy?

PURPOSE OF REVIEW

To summarize available evidence on the potential utility of pretreatment with intravenous thrombolysis (IVT) using recombinant tissue-plasminogen activator (rt-PA) in acute ischemic stroke (AIS) patients with large vessel occlusions (LVO) who are treated with mechanical thrombectomy.

RECENT FINDINGS

Despite theoretical concerns of a higher bleeding risk with IVT pretreatment, there are no data showing increased risk of symptomatic intracerebral hemorrhage (sICH) in patients with LVO receiving bridging therapy (IVT and mechanical thrombectomy) compared with direct mechanical thrombectomy (dMT). Additionally, evidence from observational studies suggest lower rates of infarctions in previously unaffected territories and higher rates of successful reperfusion, with lower number of device passes, in patients receiving bridging therapy. There are substantial discrepancies in studies comparing clinical outcomes between dMT and bridging therapy that are directly related to the inclusion of patients with contraindications to IVT in the dMT group. Ongoing clinical trials will provide definitive answers on the potential additional benefit of IVT in LVO patients receiving mechanical thrombectomy.

SUMMARY

IVT and mechanical thrombectomy are two effective reperfusion therapies that should be used in a swift and noncompeting fashion in AIS patients. AIS patients with LVO and no contraindications for IVT should receive promptly rt-PA bolus followed by immediate initiation of mechanical thrombectomy as indicated by current international recommendations, unless future randomized controlled trials provide evidence to proceed differently.

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.

Surgery of acute occlusion of the extracranial internal carotid artery - a meta-analysis

Acute occlusion of the extracranial internal carotid artery (eICA) is associated with poor prognosis. Surgical desobliteration has not received adequate attention in recent years. We therefore conducted a literature review and meta-analysis of surgical studies published after 2000 that treated eICA occlusion surgically in an emergency setting. The search identified 10 relevant articles that included a total of 175 patients. The outcomes analysed included rates of recanalization (93 %), early neurological improvement (66 %), modified Rankin Scale 0-2 (62 %), mortality (5 %), early reocclusion (4 %), in-hospital stroke (4 %) and symptomatic intracerebral haemorrhage (4 %). In conclusion, acute surgical desobliteration of eICA occlusion leads to high rates of recanalization and a majority of patients experience early neurological improvement and achieve favourable outcome. Rates of mortality, early reocclusion, in-hospital stroke and sICH are acceptable in the view of unfavourable natural history.

Intravenous fibrinolysis plus endovascular thrombectomy versus direct endovascular thrombectomy for anterior circulation acute ischemic stroke: clinical and infarct volume results

Background

endovascular therapy (ET) is the standard of care for anterior circulation acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). The role of adjunctive intravenous thrombolysis (IVT) in these patients remains unclear. The present study aims to investigate whether IVT followed by ET (CoT, combined therapy) provides additional benefits over direct ET for anterior circulation AIS with LVO.

Methods

we achieved a single center retrospective study of patients with AIS caused by anterior circulation LVO, referred to our center between January 2014 and January 2017 and treated with ET. Functional recovery (modified Rankin at 3-months follow-up), recanalization rate (thrombolysis in cerebral infarction [TICI] score) and time, early follow-up brain CT scan infarct volume (EFIV) (for recanalized patients only), symptomatic intracerebral hemorrhage (sICH) and 3-month mortality were the outcomes of interests. Independent predictors of the outcomes were explored with multivariable logistic regression.

Results

145 subjects were included in the study, of whom 70 underwent direct ET and 75 were treated with CoT. Functional independence at 3-months was more frequent in CoT subjects compared to patients who received direct ET (mRS score 0–1: 48.5% vs 18.6%; P < 0.001. mRS score 0–2: 67.1% vs 37.3%; P < 0.001); CoT patients had also higher first-pass success rate (62.7% vs 38.6%, P < 0.05), higher recanalization rate (84.3% vs 65.3%; P = 0.009) and, in recanalized subjects, smaller EFIV (16.4 ml vs 62.3 ml; P = 0.003). Mortality and intracranial bleeding did not differ between the two groups. In multivariable regression analysis, low baseline NIHSS score (P < 0.05), vessel recanalization (P = 0.05) and CoT (P = 0.03) were independent predictors of favorable outcome at three months.

Conclusions

CoT appears more effective than ET alone for anterior circulation AIS with LVO, with similar safety profile.

Combined intravenous and endovascular treatment versus primary mechanical thrombectomy. The Italian Registry of Endovascular Treatment in Acute Stroke

Background

Whether mechanical thrombectomy alone may achieve better or at least equal clinical outcome than mechanical thrombectomy combined with intravenous thrombolysis is a matter of debate.

Methods

From the Italian Registry of Endovascular Stroke Treatment, we extracted all cases treated with intravenous thrombolysis followed by mechanical thrombectomy or with primary mechanical thrombectomy for anterior circulation stroke due to proximal vessel occlusion. We included only patients who would have qualified for intravenous thrombolysis. We compared outcomes of the two groups by using multivariate regression analysis and propensity score method.

Results

We included 1148 patients, treated with combined intravenous thrombolysis and mechanical thrombectomy therapy (n = 635; 55.3%), or with mechanical thrombectomy alone (n = 513; 44.7%). Demographic and baseline clinical characteristics did not differ between the two groups, except for a shorter onset to groin puncture time (p < 0.05) in the mechanical thrombectomy group. A shift in the 90-day modified Rankin Scale distributions toward a better outcome was found in favor of the combined treatment (adjusted common odds ratio  = 1.3; 95% confidence interval: 1.04–1.66). Multivariate analyses on binary outcome show that subjects who underwent combined treatment had higher probability to survive with modified Rankin Scale 0–3 (odds ratio = 1.42; 95% confidence interval: 1.04–1.95) and lower case fatality rate (odds ratio = 0.6; 95% confidence interval: 0.44–0.9). Hemorrhagic transformation did not differ between the two groups.

Conclusion

These data seem to indicate that combined intravenous thrombolysis and mechanical thrombectomy could be associated with lower probability of death or severe dependency after three months from stroke due to large vessel occlusion, supporting the current guidelines of treating eligible patients with intravenous thrombolysis before mechanical thrombectomy.

Effectiveness of Low-Dose Intravenous Tissue Plasminogen Activator before Stent Retriever or Aspiration Mechanical Thrombectomy

PURPOSE

To determine whether thrombolysis with a lower dose of intravenous recombinant tissue plasminogen activator before mechanical thrombectomy is beneficial for functional outcomes compared with mechanical thrombectomy alone.

MATERIALS AND METHODS

Data for 100 Japanese patients who underwent mechanical thrombectomy between July 2014 and November 2017 were retrospectively reviewed. These patients were divided into groups according to whether they received intravenous thrombolysis before mechanical thrombectomy, and outcomes were compared. Favorable outcome was defined as a modified Rankin scale score ≤ 2 at 3 months after treatment.

RESULTS

Thirty-four patients for the thrombolysis group and 66 patients for the thrombectomy-only group were identified. The thrombolysis and nonthrombolysis groups did not differ significantly in baseline characteristics (mean age, 74.3 y vs 75.7 y [P = .485]; mean preoperative National Institute Health Stroke Scale score, 19.8 vs 19.6 [P = .825]). There were no significant differences in the times required for, or the rates of, successful recanalization. However, the thrombolysis group had a higher rate of complete recanalization (67.6% vs 43.9%; P = .041). Postoperative symptomatic intracranial hemorrhage was not significantly different between groups. Favorable outcomes were observed in 73.5% of patients in the thrombolysis group and 51.5% in the nonthrombolysis group (P = .028).

CONCLUSIONS

This single-center retrospective study shows that lower-dose intravenous thrombolysis improves the outcomes of mechanical thrombectomy for Japanese patients with acute anterior-circulation stroke treated within 4.5 hours of onset.

Direct endovascular thrombectomy and bridging strategies for acute ischemic stroke: a network meta-analysis

OBJECTIVES

The present Bayesian network meta-analysis aimed to compare the various strategies for acute ischemic stroke: direct endovascular thrombectomy within the thrombolysis window in patients with no contraindications to thrombolysis (DEVT); (2) direct endovascular thrombectomy secondary to contraindications to thrombolysis (DEVTc); (3) endovascular thrombectomy in addition to thrombolysis (IVEVT); and (4) thrombolysis without thrombectomy (IVT).

METHODS

Six electronic databases were searched from their dates of inception to May 2017 to identify randomized controlled trials (RCTs) comparing IVT versus IVEVT, and prospective registry studies comparing IVEVT versus DEVT or IVEVT versus DEVTc. Network meta-analyses were performed using ORs and 95% CIs as the summary statistic.

RESULTS

We identified 12 studies (5 RCTs, 7 prospective cohort) with a total of 3161 patients for analysis. There was no significant difference in good functional outcome at 90 days (modified Rankin Scale score ≤2) between DEVT and IVEVT. There was no significant difference in mortality between all treatment groups. DEVT was associated with a 49% reduction in intracranial hemorrhage (ICH) compared with IVEVT (OR 0.51; 95% CI 0.33 to 0.79), due to reduction in rates of asymptomatic ICH (OR 0.47; 95% CI 0.29 to 0.76). Patients treated with DEVT had higher rates of reperfusion compared with IVEVT (OR 1.73; 95% CI 1.04 to 2.94).

CONCLUSIONS

To our knowledge, this is the first network meta-analysis to be performed in the era of contemporary mechanical thrombectomy comparing DEVT and DEVTc. Our analysis suggests the addition of thrombolysis prior to thrombectomy for large vessel occlusions may not be associated with improved outcomes.

Making a case for the right '-ase' in acute ischemic stroke: alteplase, tenecteplase, and reteplase

INTRODUCTION

Alteplase, reteplase, and tenecteplase are tissue plasminogen activators (TPA) approved for the management of acute myocardial infarction. Only alteplase is also approved for the treatment of acute ischemic stroke (AIS). The US Food and Drug Administration has received reports of accidental administration of tenecteplase or reteplase instead of alteplase in patients with AIS, which can result in failure to treat patients with the intended agent and lead to potential overdose.

AREAS COVERED

This review compares the molecular and clinical features of alteplase, reteplase, and tenecteplase (TNK), identifies factors contributing to medication errors among these agents, and provides steps to reduce medication errors.

EXPERT OPINION

Primary factors contributing to medication errors among tissue plasminogen activators include the use of the abbreviations 'TPA,' 'tPA,' or 'TNK' in written or verbal orders and use of these agents in similar settings (e.g. emergency departments and critical care areas). Steps to reduce the likelihood of accidental substitution of tenecteplase or reteplase for alteplase in patients with AIS include the use of full brand or generic names and inclusion of the indication in written and verbal orders, the addition of alerts in automated dispensing machines and ordering systems and use of stroke boxes containing alteplase and materials for administration.

Bridging Therapy Versus Direct Mechanical Thrombectomy in Patients with Acute Ischemic Stroke due to Middle Cerebral Artery Occlusion: A Clinical- Histological Analysis of Retrieved Thrombi

Mechanical thrombectomy (MT) is effective in managing patients with acute ischemic stroke (AIS) caused by large-vessel occlusions and allows for valuable histological analysis of thrombi. However, whether bridging therapy (pretreatment with intravenous thrombolysis before MT) provides additional benefits in patients with middle cerebral artery (MCA) occlusion remains unclear. Therefore, this study aimed to compare the effects of direct MT and bridging therapy, and to elucidate the correlation between thrombus composition and stroke subtypes. Seventy-three patients with acute ischemic stroke who received MT, were eligible for intravenous thrombolysis, and had MCA occlusion were included. We matched 21 direct MT patients with 21 bridging therapy patients using propensity score matching and compared their 3rd-month clinical outcomes. All MCA thrombi (n = 45) were histologically analyzed, and the red blood cell (RBC) and fibrin percentages were quantified. We compared the clot composition according to stroke etiology (large-artery atherosclerosis and cardioembolism) and intravenous thrombolysis application. The baseline characteristics showed no difference between groups except for a higher atrial fibrillation rate and NIHSS score on admission in the direct MT group. We performed a supportive analysis using propensity score matching but could not find any differences in the functional outcome, mortality, and intracerebral hemorrhage. In the histological clot analysis, the cardioembolic clots without intravenous thrombolysis pretreatment had higher RBC (P = 0.042) and lower fibrin (P = 0.042) percentages than the large-artery atherosclerosis thrombi. Similar findings were observed in the thrombi treated with recombinant tissue plasminogen activator (P = 0.012). In conclusion, there was no difference in the functional outcomes between the direct MT and bridging therapy groups. However, randomized trials are needed to elucidate the high ratio of cardioembolism subtype in our group of patients. The histological MCA thrombus composition differed between cardioembolism and large-artery atherosclerosis, and this finding provides valuable information on the underlying pathogenesis and thrombus origin.

The Efficacy of IV Tissue Plasminogen Activator for Restoring Cerebral Blood Flow in the Hours Immediately after Administration in Patients with Acute Stroke

BACKGROUND AND PURPOSE

Timely restoration of tissue-level cerebral blood flow is the goal of thrombolytic therapy in patients presenting with an acute ischemic stroke. We aimed to identify the incidence and predictors of reperfusion immediately following treatment with intravenous recombinant tissue plasminogen activator (IV rt-PA).

METHODS

This study included patients with acute ischemic stroke triaged using magnetic resonance imaging (MRI) with perfusion-weighted imaging (PWI) and treated with IV rt-PA who were subsequently enrolled in our natural history study and underwent repeat MRI with PWI approximately 2 hours posttreatment. Early reperfusion was defined as >80% decrease in the size of initial perfusion deficit on the 2 hours follow-up MRI. Demographics, stroke risk factors, presenting National Institutes of Health Stroke Scale score, and location of the thrombosis were compared between patients with and without early reperfusion.

RESULTS

Of the 49 patients included in this study, 21 (43%) had early reperfusion. The mean age for patients with early reperfusion was significantly lower in comparison to the patients without early reperfusion (64 vs. 76, P = .01). The prevalence of hyperlipidemia was significantly lower among patients with early reperfusion (24% vs. 54%, P = .036). Patients with early reperfusion were less likely to have large-vessel occlusion (LVO) (internal carotid artery terminus or proximal middle cerebral artery) (24% vs. 50%, P = .06). In a multivariate analysis, the presence of an LVO was an independent predictor of lack of early reperfusion (OR [95%Cl]: .13 [.019-.89], P = .038).

CONCLUSION

Early reperfusion was found in a substantial percentage of the patients treated with IV rt-PA. It was more common in patients without LVO.

Direct Thrombectomy versus Bridging for Patients with Emergent Large-Vessel Occlusions

Background and Aims

Patients with emergent large-vessel occlusion (ELVO) that present earlier than 4 h from onset are usually treated with bridging systemic thrombolysis followed by endovascular thrombectomy (EVT). Whether direct EVT (dEVT) could improve the chances of favorable outcome remains unknown.

Methods

Consecutively, prospectively enrolled patients with ELVO presenting within 4 h of onset were entered into a National Acute Stroke Registry of patients undergoing revascularization. Patients treated with bridging were compared to those treated with dEVT. Excellent outcome was defined as having a modified Rankin Scale score ≤1 at 90 days following stroke.

Results

Out of 392 patients that underwent thrombectomy, 270 (68%) presented within 4 h and were included. Of those, 159 (59%) underwent bridging and 111 (41%) underwent dEVT. Atrial fibrillation and congestive heart failure were more common in the dEVT group (43 vs. 30%, p = 0.04 and 20 vs. 8%, p = 0.009, respectively), but other risk factors, demographics, stroke severity and subtypes as well as baseline vessel patency state and time metrics did not differ. Excellent target vessel recanalization defined as TICI 3 (thrombolysis in cerebral infarction score) was more common in the dEVT group (75 vs. 61%, p = 0.03), but in-hospital mortality, discharge destinations, short- and long-term excellent outcome rates did not differ. On multivariate regression analysis, treatment modality did not significantly modify the chances of excellent outcome at discharge (OR 0.7; 95% CI 0.3-1.5) or at 3 months (OR 0.78 95% CI 0.4-1.4).

Conclusions

The chances of attaining excellent functional outcomes are similar in ELVO patients undergoing dEVT or bridging.

Intravenous thrombolysis for acute ischemic stroke: a bridge between two centuries

INTRODUCTION

Intravenous tissue-plasminogen activator (tPA) remains the only approved systemic reperfusion therapy suitable for most patients presenting timely with acute ischemic stroke. Accumulating real-word experience for over 20 years regarding tPA safety and effectiveness led to re-appraisal of original contraindications for intravenous thrombolysis (IVT). Areas covered: This narrative review focuses on fast yet appropriate selection of patients for safe administration of tPA per recently expanded indications. Novel strategies for rapid patient assessment will be discussed. The potential for mobile stroke units (MSU) that shorten onset-to-needle time and increase tPA treatment rates is addressed. The use of IVT in the era of non-vitamin K antagonist oral anticoagulants (NOACs) is highlighted. The continuing role of IVT in large vessel occlusion (LVO) patients eligible for mechanical thrombectomy (MT) is discussed with regards to 'drip and ship' vs. 'mothership' treatment paradigms. Promising studies of penumbral imaging to extend IVT beyond the 4.5-hour window and in wake-up strokes are summarized. Expert commentary: This review provides an update on the role of IVT in specific conditions originally considered tPA contraindications. Novel practice challenges including NOAC's, MSU proliferation and bridging therapy (IVT&MT) for LVO patients, and the potential extension of IVT time-window using penumbral imaging are emerging as safe and potentially effective IVT applications.

Intravenous Recombinant Tissue-Type Plasminogen Activator: Influence on Outcome in Anterior Circulation Ischemic Stroke Treated by Mechanical Thrombectomy

BACKGROUND AND PURPOSE

Intravenous thrombolysis (IVT) followed by mechanical thrombectomy (MT) improves functional outcome in patients with ischemic stroke related to proximal-vessel occlusion in the anterior circulation. Whether MT alone is as effective as IVT/MT remains controversial. We aimed at evaluating the influence of IVT in patients with large anterior circulation artery occlusion treated with MT.

METHODS

We did a prospective observational cohort study in patients with stroke related to large anterior circulation artery occlusion treated by MT who were admitted to Lille University Hospital, Lille, France. We evaluated the influence of IVT on favorable functional outcome (defined as a modified Rankin Scale score 0-2 or similar to the prestroke modified Rankin Scale) and on mortality at month 3. Between-group comparisons in outcomes were adjusted for prespecified confoundors by using a propensity score-adjusted approach.

RESULTS

From January 2012 to January 2017, we included 485 patients (median age, 68 years; 46% men; 348 [72%] in the IVT/MT group; 137 [28%] in the MT group). In MT group, 22% of patients had a favorable outcome versus 35% in IVT/MT group (adjusted relative risk, 1.76; 95% confidence interval, 1.23-2.55). Mortality within 3 months occurred less frequently in IVT/MT group (14% versus 32%; adjusted relative risk, 0.46; 95% confidence interval, 0.31-0.70). Successful reperfusion (Thrombolysis in Cerebral Infarction scale 2b-3) was more frequent in IVT/MT group (75% versus 60%; adjusted relative risk, 1.30; 95% confidence interval, 1.11-1.53). There was no difference between groups on hemorrhagic complications.

CONCLUSIONS

In this population, previous IVT improved functional outcome and survival at 3 months in patients treated by MT. While waiting for randomized controlled trials, this result encourages not to avoid IVT before MT.

Comparative safety and efficacy of combined IVT and MT with direct MT in large vessel occlusion

OBJECTIVE

In this multicenter study, we sought to evaluate comparative safety and efficacy of combined IV thrombolysis (IVT) and mechanical thrombectomy (MT) vs direct MT in emergent large vessel occlusion (ELVO) patients.

METHODS

Consecutive ELVO patients treated with MT at 6 high-volume endovascular centers were evaluated. Standard safety and efficacy outcomes (successful reperfusion [modified Thrombolysis in Cerebral Infarction IIb/III], functional independence [FI] [modified Rankin Scale (mRS) score of 0-2 at 3 months], favorable functional outcome [mRS of 0-1 at 3 months], functional improvement [mRS shift by 1-point decrease in mRS score]) were compared between patients who underwent combined IVT and MT vs MT alone. Additional propensity score-matched analyses were performed.

RESULTS

A total of 292 and 277 patients were treated with combination therapy and direct MT, respectively. The combination therapy group had greater functional improvement (p = 0.037) at 3 months. After propensity score matching, 104 patients in the direct MT group were matched to 208 patients in the combination therapy group. IVT pretreatment was independently (p < 0.05) associated with higher odds of FI (odds ratio [OR] 1.75; 95% confidence interval [CI] 1.02-2.99) and functional improvement (common OR 1.64; 95% CI 1.05-2.56). Combination therapy was independently (p < 0.05) related to lower likelihood of 3-month mortality (0.50; 95% CI 0.26-0.96).

CONCLUSIONS

This observational study provides preliminary evidence that IVT pretreatment may improve outcomes in ELVO patients treated with MT. The question of the potential effect of IVT on ELVO patients treated with MT should be addressed with a randomized controlled trial.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that for stroke patients with emergent large vessel occlusion, combined IVT and MT is superior to direct MT in improving functional outcomes.

Current evidence for endovascular therapy in stroke and remaining uncertainties

Class 1 level A evidence now supports endovascular thrombectomy as best practice in the management of large vessel occlusion acute ischaemic stroke. However, significant questions pertaining to initial imaging, radiological assessment, patient selection and therapeutic limits remain unanswered. A specific cohort of patients who benefit from endovascular thrombectomy has been established, although current uncertainties regarding selection of those not meeting top-tier evidence criteria may potentially deny certain patients the benefit of intervention. This is of particular relevance in patients presenting in a delayed manner. Whilst superior outcomes are achieved with reduced time to endovascular reperfusion, denying patients intervention based on symptom duration alone may not be appropriate. Advanced understanding of ischaemic stroke pathophysiology supports an individualized approach to patient evaluation, given variance in the rate of ischaemic core progression and the extent of salvageable penumbra. Physiological imaging techniques may therefore be utilized to better inform patient selection for endovascular thrombectomy and evidence suggests that a transition from time-based to tissue-based therapeutic thresholds may be of greater value. Multiple ongoing randomized controlled trials aim to further define the benefit of endovascular thrombectomy and it is hoped that these results will advance, and possibly broaden, patient selection criteria to ensure that maximum benefit from the intervention may be achieved.

Antiplatelet pretreatment and outcomes following mechanical thrombectomy for emergent large vessel occlusion strokes

BACKGROUND

Few data are available regarding the safety and efficacy of antiplatelet (APT) pretreatment in acute ischemic stroke (AIS) patients with emergent large vessel occlusions (ELVO) treated with mechanical thrombectomy (MT). We sought to evaluate the association of APT pretreatment with safety and efficacy outcomes following MT for ELVO.

METHODS

Consecutive ELVO patients treated with MT during a 4-year period in a tertiary stroke center were evaluated. The following outcomes were documented using standard definitions: symptomatic intracranial hemorrhage (sICH), successful recanalization (SR; modified TICI score 2b/3), mortality, and functional independence (modified Rankin Scale scores of 0-2).

RESULTS

The study population included 217 patients with ELVO (mean age 62±14 years, 50% men, median NIH Stroke Scale score 16). APT pretreatment was documented in 71 cases (33%). Patients with APT pretreatment had higher SR rates (77% vs 61%; P=0.013). The two groups did not differ in terms of sICH (6% vs 7%), 3-month mortality (25% vs 26%), and 3-month functional independence (50% vs 48%). Pretreatment with APT was independently associated with increased likelihood of SR (OR 2.18, 95% CI1.01 to 4.73; P=0.048) on multivariable logistic regression models adjusting for potential confounders. A significant interaction (P=0.014) of intravenous thrombolysis (IVT) pretreatment on the association of pre-hospital antiplatelet use with SR was detected. APT pretreatment was associated with SR (OR 2.74, 95% CI 1.15 to 6.54; P=0.024) in patients treated with combination therapy (IVT and MT) but not in those treated with direct MT (OR 1.78, 95% CI 0.63 to 5.03; P=0.276).

CONCLUSION

APT pretreatment does not increase the risk of sICH and may independently improve the odds of SR in patients with ELVO treated with MT. The former association appears to be modified by IVT.

Successful Reperfusion With Intravenous Thrombolysis Preceding Mechanical Thrombectomy in Large-Vessel Occlusions

BACKGROUND AND PURPOSE

Although current guidelines advocate pretreatment with intravenous thrombolysis (IVT) in all eligible patients with acute ischemic stroke with large-vessel occlusion before mechanical thrombectomy, there are observational data questioning the efficacy of this approach. One of the main arguments in favor of IVT pretreatment is the potential for tissue-type plasminogen activator-induced successful reperfusion (SR) before the onset of endovascular procedure.

METHODS

We performed a systematic review and meta-analysis of randomized controlled clinical trials and observational cohorts providing rates of SR with IVT in patients with large-vessel occlusion before the initiation of mechanical thrombectomy. We also performed subgroup analyses according to study type (randomized controlled clinical trials versus observational) and according to the inclusion per protocol of patients with tandem (intracranial/extracranial) occlusions.

RESULTS

We identified 13 eligible studies (7 randomized controlled clinical trials and 6 observational cohorts), including 1561 patients with acute ischemic stroke (median National Institutes of Health Stroke Scale score, 17) with large-vessel occlusion. SR following IVT and before mechanical thrombectomy was documented in 11% (95% confidence interval, 7%-16%), with no difference among cohorts derived from randomized controlled clinical trials and observational studies. There was significant heterogeneity across included studies both in the overall analysis and among subgroups (I²>84%; P for Cochran Q, <0.001). Higher tissue-type plasminogen activator-induced SR rates were documented in studies reporting the exclusion of tandem occlusions (17%; 95% confidence interval, 11%-23%) compared with the rest (7%; 95% confidence interval, 4%-11%; P for subgroup differences, 0.003).

CONCLUSIONS

Pretreatment with systemic thrombolysis in patients with large-vessel occlusion eligible for mechanical thrombectomy results in SR in 1 of 10 cases, negating the need for additional endovascular reperfusion. Tandem occlusions seem to be the least responsive to IVT pretreatment.

Vascular medicine and thrombectomy in stroke

The treatment of stroke caused by intracranial vessel occlusion with intravenous recombinant tissue plasminogen activator (rt-PA) was the only evidence-based treatment option for a long time. Nevertheless the response rate was disappointing in large vessel occlusions. Five studies that evaluated the efficacy of mechanical thrombectomy published in 2015 proved a significant clinical benefit for selected patients suffering from acute ischemic stroke. These results are the basis for extensive technical, institutional, and personal structural changes in the neurovascular field of stroke treatment. This review gives an overview of the current status of mechanical thrombectomy and future expectations and challenges are discussed.

Direct Mechanical Intervention Versus Bridging Therapy in Stroke Patients Eligible for Intravenous Thrombolysis: A Pooled Analysis of 2 Registries

BACKGROUND AND PURPOSE

Randomized controlled trials have shown that mechanical thrombectomy (MT) plus best medical treatment improves outcome in stroke patients with large-vessel occlusion in the anterior circulation. Whether direct MT is equally effective as bridging thrombolysis (intravenous thrombolysis plus MT) in intravenous thrombolysis eligible patients remains unclear.

METHODS

We compared clinical and radiological outcomes at 3 months in 249 bridging patients with 111 patients receiving direct MT for large-vessel occlusion anterior circulation stroke from 2 prospective registries (study period Essen: June 2012 to August 2013, Bern February 2009 to August 2014). We matched all patients from the direct MT group who would have qualified for intravenous thrombolysis with controls from the bridging group, using multivariate and propensity score methods. Subgroup analyses for internal carotid artery occlusions were performed.

RESULTS

Baseline characteristics did not differ between the direct MT group and bridging cohort, except for higher rates of coronary heart disease (P=0.029) and shorter intervals from onset to endovascular therapy (P<0.001) in the MT group. Functional outcome, mortality, and intracerebral hemorrhage did not differ, neither in univariate nor after multivariate and propensity score matching. However, in patients with internal carotid artery occlusion, mortality in the direct cohort was significantly lower.

CONCLUSIONS

In this matched-pair analysis, there was no difference in outcome in patients with large-vessel occlusion anterior circulation stroke treated with direct MT compared with those treated with bridging thrombolysis; however, mortality in patients with internal carotid artery occlusion treated with direct MT was significantly lower than after bridging thrombolysis. Randomized trials comparing direct MT with bridging therapy are needed.