Direct Mechanical Thrombectomy Versus Combined Intravenous and Mechanical Thrombectomy in Large-Artery Anterior Circulation Stroke

Endovascular thrombectomy with versus without intravenous thrombolysis in patients with acute basilar artery occlusion: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

The benefit and safety of intravenous thrombolysis before endovascular thrombectomy in patients with acute ischemic stroke caused by basilar artery occlusion (BAO) remains unclear. This article aims to investigate the clinical outcomes and safety of endovascular thrombectomy with versus without intravenous thrombolysis in acute BAO stroke patients.

METHODS

We conducted a comprehensive search of PubMed, Embase, Cochrane, and Web of Science databases to identify relevant literature pertaining to patients with acute BAO who underwent endovascular thrombectomy alone or intravenous thrombolysis bridging with endovascular thrombectomy (bridging therapy), until January 10, 2024. The primary outcome was functional independence, defined as a score of 0-2 on the modified Rankin Scale at 90 days. The safety outcome was mortality at 90 days and symptomatic intracranial hemorrhage within 48 h. Effect sizes were computed as risk ratio (RR) with random-effect models. This study was registered in PROSPERO (CRD42023462293).

RESULTS

A total of 528 articles were obtained through the search and articles that did not meet the inclusion criteria were excluded. Finally, 2 RCTs and 10 cohort studies met the inclusion criteria. The findings revealed that the endovascular thrombectomy alone group had a lower rate of functional independence compared to the bridging therapy group (29% vs 38%; RR 0.78, 95% CI 0.68-0.88, p < 0.001), lower independent ambulation (39% vs 45%; RR 0.89, 95% CI 0.82-0.98, p = 0.01), and higher mortality (36% vs 28%, RR 1.22, 95% CI 1.08-1.37, p = 0.001). However, no differences were detected in symptomatic intracranial hemorrhage between the two groups (6% vs 4%; RR 1.12, 95% CI 0.74-1.71, p = 0.58).

CONCLUSION

Intravenous thrombolysis plus endovascular thrombectomy seemed to led to better functional independence, independent ambulation, and lower risk of mortality without increasing the incidence of intracranial hemorrhage compared to endovascular thrombectomy alone. However, given the non-randomized nature of this study, further studies are needed to confirm these findings.

Diesel exhaust particles exposure exacerbates pro-thrombogenic plasma features ex-vivo after cerebral ischemia and accelerates tPA-induced clot-lysis in hypertensive subjects

The combustion of fossil fuels, mainly by diesel engines, generates Diesel Exhaust Particles (DEP) which are the main source of Particulate Matter (PM), a major air pollutant in urban areas. These particles are a risk factor for stroke with 5.6% of cases attributed to PM exposure. Our aim was to evaluate the effect of DEP exposure on clot formation and lysis in the context of stroke. An ex-vivo clot formation and lysis turbidimetric assay has been conducted in human and mouse plasma samples from ischemic stroke or control subjects exposed to DEP or control conditions. Experimental DEP exposure was achieved by nasal instillation in mice, or by ex-vivo exposure in human plasma. Results show consistent pro-thrombogenic features in plasma after human ischemic stroke and mouse cerebral ischemia (distal MCAo), boosted by the presence of DEP. Otherwise, thrombolysis times were increased after ischemia in chronically exposed mice but not in the DEP exposed group. Finally, subjects living in areas with high PM levels presented accelerated thrombolysis compared to those living in low polluted areas. Overall, our results point at a disbalance of the thrombogenic/lytic system in presence of DEP which could impact on ischemic stroke onset, clot size and thrombolytic treatment.

Thrombolysis in Stroke-Heart Syndrome: a useful tool for neurocardiac wellness?

INTRODUCTION

Stroke-heart syndrome is a physiopathological condition of cardiac suffering due to cerebral injury secondary to major vessel occlusion in anterior circulation. It can be detected by increase in cardiac blood biomarkers. Our aim was to investigate a possible ancillary effect of thrombolysis in mitigating Stroke-Heart Syndrome after acute ischaemic stroke.

PATIENTS AND METHODS

We retrospectively collected ischaemic stroke patients admitted to our Stroke Unit between August 1, 2017 and December 31, 2020 and acutely treated for an intracranial anterior circulation occlusion, without anamnestic ischaemic cardiopathy. We divided patients into Group B ("Bridge") including patients treated with both thrombolysis and thrombectomy and Group D ("Direct") including primary thrombectomies.

RESULTS

120 patients were included in the study. Group B consisted of 92 patients, Group D of 28 patients, without significant differences in age, baseline and discharge NIHSS, cardiovascular risk factors or TOAST aetiology. Whilst admission, troponin levels were similar in both groups, significant differences in troponin peak (median 16 ng/L in Group B vs 45 ng/L in Group D, p = 0.022) and BNP values (median 455 pg/mL in Group B vs 784 pg/mL in Group D, p = 0.031) were found in the first 72 h since admission. Functional independence at discharge was significantly higher in Group B than Group D (mRS 0-2 36% vs 10%, p = 0.011).

DISCUSSION AND CONCLUSION

Significant differences in troponin peak and BNP values suggest a reduced stroke-related heart impairment in patients treated with bridge therapeutic approach: thrombolysis prior to thrombectomy could have a complementary effect on reducing Stroke-Heart Syndrome, improving overall neurological outcome.

Influencing factors of futile recanalization after endovascular intervention in patients with acute basilar artery occlusion

OBJECTIVES

To explore the influence factors for futile recanalization following endovascular treatment (EVT) in patients with acute basilar artery occlusion (BAO).

METHODS

Clinical data of patients with acute BAO, who underwent endovascular treatment within 24 h of onset from January 2017 to November 2022, were retrospectively analyzed. The futile recanalization was defined as modified thrombolysis in cerebral infarction (mTICI) grade ≥2b or 3 after successful reperfusion, but the modified Rankin Scale score >2 at 3 months after EVT. Binary logistic regression model was used to analyze the influencing factors of futile recanalization.

RESULTS

A total of 471 patients with a median age of 68 (57, 74) years were included and 68.9% were males, among whom 298 (63.27%) experienced futile recanalization. Multivariate analysis revealed that concomitant atrial fibrillation (OR=0.456, 95%CI: 0.282-0.737, P<0.01), bridging thrombolysis (OR=0.640, 95%CI: 0.416-0.985, P<0.05), achieving mTICI grade 3 (OR=0.554, 95%CI: 0.334-0.918, P<0.05), arterial occlusive lesion (AOL) grade 3 (OR=0.521, 95%CI: 0.326-0.834, P<0.01), and early postoperative statin therapy (OR=0.509, 95%CI: 0.273-0.948, P<0.05) were protective factors for futile recanalization after EVT in acute BAO patients. High baseline National Institutes of Health Stroke Scale (NIHSS) score (OR=1.068, 95%CI: 1.049-1.087, P<0.01), coexisting hypertension (OR=1.571, 95%CI: 1.017-2.427, P<0.05), multiple retrieval attempts (OR=1.237, 95%CI: 1.029-1.488, P<0.05) and postoperative hemorrhagic transformation (OR=8.497, 95%CI: 2.879-25.076, P<0.01) were risk factors. For trial of ORG 10172 in acute stroke treatment (TOAST) classification, cardiogenic embolism (OR=0.321, 95%CI: 0.193-0.534, P<0.01) and other types (OR=0.499, 95%CI: 0.260-0.961, P<0.05) were related to lower incidence of futile recanalization.

CONCLUSIONS

The incidence of futile recanalization after EVT in patients with acute BAO is high. Bridging venous thrombolysis before operation and an early postoperative statin therapy may reduce the incidence of futile recanalization.

Time to Treatment With Intravenous Thrombolysis Before Thrombectomy and Functional Outcomes in Acute Ischemic Stroke: A Meta-Analysis

Importance

The benefit of intravenous thrombolysis (IVT) for acute ischemic stroke declines with longer time from symptom onset, but it is not known whether a similar time dependency exists for IVT followed by thrombectomy.

Objective

To determine whether the benefit associated with IVT plus thrombectomy vs thrombectomy alone decreases with treatment time from symptom onset.

Design, Setting, and Participants

Individual participant data meta-analysis from 6 randomized clinical trials comparing IVT plus thrombectomy vs thrombectomy alone. Enrollment was between January 2017 and July 2021 at 190 sites in 15 countries. All participants were eligible for IVT and thrombectomy and presented directly at thrombectomy-capable stroke centers (n = 2334). For this meta-analysis, only patients with an anterior circulation large-vessel occlusion were included (n = 2313).

Exposure

Interval from stroke symptom onset to expected administration of IVT and treatment with IVT plus thrombectomy vs thrombectomy alone.

Main Outcomes and Measures

The primary outcome analysis tested whether the association between the allocated treatment (IVT plus thrombectomy vs thrombectomy alone) and disability at 90 days (7-level modified Rankin Scale [mRS] score range, 0 [no symptoms] to 6 [death]; minimal clinically important difference for the rates of mRS scores of 0-2: 1.3%) varied with times from symptom onset to expected administration of IVT.

Results

In 2313 participants (1160 in IVT plus thrombectomy group vs 1153 in thrombectomy alone group; median age, 71 [IQR, 62 to 78] years; 44.3% were female), the median time from symptom onset to expected administration of IVT was 2 hours 28 minutes (IQR, 1 hour 46 minutes to 3 hours 17 minutes). There was a statistically significant interaction between the time from symptom onset to expected administration of IVT and the association of allocated treatment with functional outcomes (ratio of adjusted common odds ratio [OR] per 1-hour delay, 0.84 [95% CI, 0.72 to 0.97], P = .02 for interaction). The benefit of IVT plus thrombectomy decreased with longer times from symptom onset to expected administration of IVT (adjusted common OR for a 1-step mRS score shift toward improvement, 1.49 [95% CI, 1.13 to 1.96] at 1 hour, 1.25 [95% CI, 1.04 to 1.49] at 2 hours, and 1.04 [95% CI, 0.88 to 1.23] at 3 hours). For a mRS score of 0, 1, or 2, the predicted absolute risk difference was 9% (95% CI, 3% to 16%) at 1 hour, 5% (95% CI, 1% to 9%) at 2 hours, and 1% (95% CI, -3% to 5%) at 3 hours. After 2 hours 20 minutes, the benefit associated with IVT plus thrombectomy was not statistically significant and the point estimate crossed the null association at 3 hours 14 minutes.

Conclusions and Relevance

In patients presenting at thrombectomy-capable stroke centers, the benefit associated with IVT plus thrombectomy vs thrombectomy alone was time dependent and statistically significant only if the time from symptom onset to expected administration of IVT was short.

Bridging techniques compared with direct endovascular therapy for stroke due to tandem occlusion: A systematic review and meta-analysis

The superiority of the bridging strategy of intravenous thrombolysis (IVT) plus endovascular therapy (EVT) to EVT alone for the anterior circulation with tandem vascular occlusion (TO) has not been specifically addressed by a single randomized trial. Analysis of 15 studies (n = 1857 patients) revealed that 90 Day good functional outcomes (MRS≤2) were better for bridging therapy (IVT + EVT) than for dEVT (OR:1.39, 95%CI: 1.09-1.79, p = 0.008); 90-day mortality was lower for IVT + EVT than for dEVT (OR: 0.57; 95%CI: 0.40-0.81, p = 0.002) and rates of successful recanalization were higher for IVT + EVT than for dEVT (OR: 1.79, 95%CI: 1.36-2.36, p<0.0001). However, there was no significant difference in the incidence of symptomatic. intracranial hemorrhage (sICH) between groups (OR 0.91, 95%CI 0.64-1.31, p = 0.62).In conclusion, Patients receiving IVT + EVT have a better functional outcome, lower death rate and a higher rate of successful recanalization than those receiving dEVT but there was no difference in sICH risk between the two treatments.

Role of NLRP3 Inflammasome in Stroke Pathobiology: Current Therapeutic Avenues and Future Perspective

Neuroinflammation is a key pathophysiological feature of stroke-associated brain injury. A local innate immune response triggers neuroinflammation following a stroke via activating inflammasomes. The nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) inflammasome has been heavily implicated in stroke pathobiology. Following a stroke, several stimuli have been suggested to trigger the assembly of the NLRP3 inflammasome. Recent studies have advanced the understanding and revealed several new players regulating NLRP3 inflammasome-mediated neuroinflammation. This article discussed recent advancements in NLRP3 assembly and highlighted stroke-induced mitochondrial dysfunction as a major checkpoint to regulating NLRP3 activation. The NLRP3 inflammasome activation leads to caspase-1-dependent maturation and release of IL-1β, IL-18, and gasdermin D. In addition, genetic or pharmacological inhibition of the NLRP3 inflammasome activation and downstream signaling has been shown to attenuate brain infarction and improve the neurological outcome in experimental models of stroke. Several drug-like small molecules targeting the NLRP3 inflammasome are in different phases of development as novel therapeutics for various inflammatory conditions, including stroke. Understanding how these molecules interfere with NLRP3 inflammasome assembly is paramount for their better optimization and/or development of newer NLRP3 inhibitors. In this review, we summarized the assembly of the NLRP3 inflammasome and discussed the recent advances in understanding the upstream regulators of NLRP3 inflammasome-mediated neuroinflammation following stroke. Additionally, we critically examined the role of the NLRP3 inflammasome-mediated signaling in stroke pathophysiology and the development of therapeutic modalities to target the NLRP3 inflammasome-related signaling for stroke treatment.

Predictive Factors of First-Pass Effect in Patients Who Underwent Successful Endovascular Thrombectomy for Emergent Large Vessel Occlusion

OBJECTIVE

The primary treatment goal of current endovascular thrombectomy (EVT) for emergent large-vessel occlusion (ELVO) is complete recanalization after a single maneuver, referred to as the 'first-pass effect' (FPE). Hence, we aimed to identify the predictive factors of FPE and assess its effect on clinical outcomes in patients with ELVO of the anterior circulation.

METHODS

Among the 129 patients who participated, 110 eligible patients with proximal ELVO (intracranial internal carotid artery and proximal middle cerebral artery) who achieved successful recanalization after EVT were retrospectively reviewed. A comparative analysis between patients who achieved FPE and all others (defined as a non-FPE group) was performed regarding baseline characteristics, clinical variables, and clinical outcomes. Multivariate logistic regression analyses were subsequently conducted for potential predictive factors with p<0.10 in the univariate analysis to determine the independent predictive factors of FPE.

RESULTS

FPE was achieved in 31 of the 110 patients (28.2%). The FPE group had a significantly higher level of functional independence at 90 days than did the non-FPE group (80.6% vs. 50.6%, p=0.002). Pretreatment intravenous thrombolysis (IVT) (odds ratio [OR], 3.179; 95% confidence interval [CI], 1.025-9.861; p=0.045), door-to-puncture (DTP) interval (OR, 0.959; 95% CI, 0.932-0.987; p=0.004), and the use of balloon guiding catheter (BGC) (OR, 3.591; 95% CI, 1.231-10.469; p=0.019) were independent predictive factors of FPE.

CONCLUSION

In conclusion, pretreatment IVT, use of BGC, and a shorter DTP interval were positively associated with FPE, increasing the chance of acquiring better clinical outcomes.

Impact of atrial fibrillation on the treatment effect of bridging thrombolysis in ischemic stroke patients undergoing endovascular thrombectomy: a multicenter international cohort study

BACKGROUND

The role of bridging intravenous thrombolysis (IVT) before endovascular thrombectomy (EVT) in the treatment of acute ischemic stroke (AIS) remains debatable. Atrial fibrillation (AF) associated strokes may be associated with reduced treatment effect from IVT. This study compares the effect of bridging IVT in AF and non-AF patients.

METHODS

This retrospective cohort study comprised anterior circulation large vessel occlusion (LVO) AIS patients receiving EVT alone or bridging IVT plus EVT within 6 hours of symptom onset. Primary outcome was good functional outcome defined as modified Rankin Scale (mRS) 0-2 at 90 days. Secondary outcomes were successful reperfusion defined as expanded Thrombolysis In Cerebral Infarction (eTICI) grading ≥2b flow, symptomatic intracerebral hemorrhage (sICH), and in-hospital mortality.

RESULTS

We included 705 patients (314 AF and 391 non-AF patients). The mean age was 68.6 years and 53.9% were male. The odds of good functional outcomes with bridging IVT was higher in the non-AF (adjusted odds ratio (aOR) 2.28, 95% CI 1.06 to 4.91, P=0.035) compared with the AF subgroups (aOR 1.89, 95% CI 0.89 to 4.01, P=0.097). However, this did not constitute a significant effect modification by the presence of AF on bridging IVT (interaction aOR 0.12, 95% CI -1.94 to 2.18, P=0.455). The rate of successful reperfusion, sICH, and mortality were similar between bridging IVT and EVT for both AF and non-AF patients.

CONCLUSION

The presence of AF did not modify the treatment effect of bridging IVT. Further individual patient data meta-analysis of randomized trials may shed light on the comparative efficacy of bridging IVT in AF versus non-AF LVO strokes.

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.

Advances in mechanical thrombectomy for acute ischaemic stroke

Mechanical thrombectomy is a ground breaking treatment for acute ischaemic stroke caused by occlusion of a large vessel. Its efficacy over intravenous thrombolysis has been proven in multiple trials with a lower number needed to treat than percutaneous coronary intervention for acute myocardial infarction. However, access to this key treatment modality remains limited with a considerable postcode lottery across the UK and many parts of the world. The evidence base for mechanical thrombectomy dates back to 2015. Since then, there have been important advances in establishing and widening the criteria for treatment. This narrative review aims to summarise the current evidence base and latest advances for physicians and academics with an interest in recanalisation treatments for acute ischaemic stroke.

Association of Intravenous Thrombolysis with Delayed Reperfusion After Incomplete Mechanical Thrombectomy

PURPOSE

Treatment of distal vessel occlusions causing incomplete reperfusion after mechanical thrombectomy (MT) is debated. We hypothesized that pretreatment with intravenous thrombolysis (IVT) may facilitate delayed reperfusion (DR) of residual vessel occlusions causing incomplete reperfusion after MT.

METHODS

Retrospective analysis of patients with incomplete reperfusion after MT, defined as extended thrombolysis in cerebral infarction (eTICI) 2a-2c, and available perfusion follow-up imaging at 24 ± 12 h after MT. DR was defined as absence of any perfusion deficit on time-sensitive perfusion maps, indicating the absence of any residual occlusion. The association of IVT with the occurrence of DR was evaluated using a logistic regression analysis adjusted for confounders. Sensitivity analyses based on IVT timing (time between IVT start and the occurrence incomplete reperfusion following MT) were performed.

RESULTS

In 368 included patients (median age 73.7 years, 51.1% female), DR occurred in 225 (61.1%). Atrial fibrillation, higher eTICI grade, better collateral status and longer intervention-to-follow-up time were all associated with DR. IVT did not show an association with the occurrence of DR (aOR 0.80, 95% CI 0.44-1.46, even in time-sensitive strata, aOR 2.28 [95% CI 0.65-9.23] and aOR 1.53 [95% CI 0.52-4.73] for IVT to incomplete reperfusion following MT timing <80 and <100 min, respectively).

CONCLUSION

A DR occurred in 60% of patients with incomplete MT at ~24 h and did not seem to occur more often in patients receiving pretreatment IVT. Further research on potential associations of IVT and DR after MT is required.

Direct Mechanical Thrombectomy vs. Bridging Therapy in Stroke Patients in A “Stroke Belt” Region of Southern Europe

The aim of this 4-year observational study is to analyze the outcomes of stroke patients treated with direct mechanical thrombectomy (dMT) compared to bridging therapy (BT) (intravenous thrombolysis [IVT] + BT) based on 3-month outcomes, in real clinical practice in the "Stroke Belt" of Southern Europe. In total, 300 patients were included (41.3% dMT and 58.6% BT). The frequency of direct referral to the stroke center was similar in the dMT and BT group, whereas the time from onset to groin was longer in the BT group (median 210 [IQR 160–303] vs. 399 [IQR 225–675], p = 0.001). Successful recanalization (TICI 2b-3) and hemorrhagic transformation were similar in both groups. The BT group more frequently showed excellent outcomes at 3 months (32.4% vs. 15.4%, p = 0.004). Multivariate analysis showed that BT was independently associated with excellent outcomes (OR 2.7. 95% CI,1.2–5.9, p = 0.02) and lower mortality (OR 0.36. 95% CI 0.16–0.82, p = 015). Conclusions: Compared with dMT, BT was associated with excellent functional outcomes and lower 3-month mortality in this real-world clinical practice study conducted in a region belonging to the “Stroke Belt” of Southern Europe. Given the disparity of results on the benefit of BT in the current evidence, it is of vital importance to analyze the convenience of its use in each health area.

A Simple Grading Scale for Predicting Symptomatic Intracranial Hemorrhage after Mechanical Thrombectomy

INTRODUCTION

Hemorrhagic transformation, especially symptomatic intracranial hemorrhage (sICH), is a common complication after mechanical embolectomy. This study explored a grading scale based on clinical and radiological parameters to predict sICH after mechanical embolectomy.

METHODS

Demographic and clinical data were retrospectively collected from patients with acute ischemic stroke treated with mechanical embolectomy at West China Hospital. Clinical and radiological factors associated with sICH were identified and used to develop the "STBA" grading scale. This score was then validated using data from an independent sample at the First Affiliated Hospital of Kunming Medical University.

RESULTS

We analyzed 268 patients with acute ischemic stroke who were treated with mechanical embolectomy at West China Hospital, of whom 30 (11.2%) had sICH. Patients were rated on an "STBA" score ranging from 0 to 6 based on whether systolic blood pressure was ≥145 mm Hg at admission (yes = 2 points; no = 0 points), time from acute ischemic stroke until groin puncture was ≥300 min (yes = 1; no = 0), blood glucose was ≥8.8 mmol/L (yes = 1; no = 0), and the Alberta Stroke Program Early Computed Tomography score at admission was 0-5 (2 points), 6-7 (1 point), or 8-10 (0 points). The STBA score showed good discrimination in the derivation sample (area under the receiver operating characteristic curve = 0.858) and in the validation sample (area = 0.814).

CONCLUSIONS

The STBA score may be a reliable clinical scoring system to predict sICH in acute ischemic stroke patients treated with mechanical embolectomy.

Mild and moderate cardioembolic stroke patients may benefit more from direct mechanical thrombectomy than bridging therapy: A subgroup analysis of a randomized clinical trial (DIRECT-MT)

Background

The benefit of intravenous alteplase before endovascular thrombectomy is unclear in patients with acute cardioembolic stroke.

Methods

We collected cardioembolic (CE) stroke patient data from the multicentre randomized clinical trial of Direct Intra-arterial Thrombectomy to Revascularize Acute Ischaemic Stroke Patients with Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals (DIRECT-MT). The primary outcome was the 90-day modified Rankin Scale (mRS) score. Five subgroups of cardioembolic stroke patients were analyzed. A multivariable ordinal logistic regression analysis analyzed the difference in the primary outcome between the direct mechanical thrombectomy (MT) and bridging therapy groups. An interaction term was entered into the model to test for subgroup interaction. The DIRECT-MT trial is registered with clinicaltrials.gov Identifier: NCT03469206.

Results

A total of 290 CE stroke patients from the DIRECT-MT trial were enrolled in this study: 146 patients in the direct MT group and 144 patients in the bridging therapy group. No difference between the two treatment groups in the primary outcome was found (adjusted common odds ratio, 1.218; 95% confidence interval, 0.806 to 1.841; P = 0.34). In the subgroup analysis, CE stroke patients with an NIHSS ≤ 15 in the direct MT group were associated with better outcomes (47 vs. 53, acOR, 3.14 [1.497, 6.585]) and lower mortality (47 vs. 53, aOR, 0.16 [0.026, 0.986]) than those in the bridging therapy group, while there were no significant differences between the two treatment groups in the outcome and mortality of CE stroke patients with an NIHSS >15.

Conclusion

Mild and moderate cardioembolic stroke patients may benefit more from direct mechanical thrombectomy than bridging therapy. This need to be confirmed by further prospective studies in a larger number of patients.

No sex difference was found in the safety and efficacy of intravenous alteplase before endovascular therapy

Background and purpose

Prior studies on sex disparities were post-hoc analyses, had limited treatment modalities, and had controversial findings. Our study aimed to examine whether sex difference modifies the effect of intravenous alteplase before endovascular therapy.

Methods

We conducted a multicenter prospective cohort study of 850 eligible patients with acute ischemic stroke who underwent endovascular therapy. A propensity score was utilized as a covariate to achieve approximate randomization of alteplase pretreatment. The baseline characteristics of women and men were compared. Logistic regression with interaction terms, adjusted for potential confounders, was used to investigate the effect of sex on the prognosis of bridging therapy.

Results

In comparison to men, women were older [78.00 (70.00–84.00) vs. 67 (61.00–74.00), P &lt; 0.001], had more atrial fibrillation (61.4 vs. 35.2%, P &lt; 0.001), had a lower ASPECTS [10.00 (8.00–10.00) vs. 10 (9.00–10.00), P = 0.0047], and had a higher NIHSS score [17.00 (14.00–20.00) vs. 16 (13.00–19.00), P = 0.005]. Women tended to receive less bridging therapy (26.3 vs. 33%, P = 0.043) and more retrieval attempts [2.00 (1.00–2.00) vs. 1 (1.00–2.00), P = 0.026]. There was no sex difference in functional independence at 90 days after bridging therapy (OR 0.968, 95% CI 0.575–1.63), whereas men benefited more after EVT alone (OR 0.654, 95% CI 0.456–0.937). There were no sex-treatment interactions observed regardless of the location of the occlusion. There were no significant sex differences in all safety outcomes.

Conclusion

Our study could not confirm that sex modifies the treatment effect of intravenous alteplase before endovascular therapy. At the same time, we advocate for women to seek timely medical treatment.

Independent Significance of Visual Assessment of Perfusion CT Maps in Anterior Circulation Stroke Patients Treated with Mechanical Thrombectomy

BACKGROUND

In the absence of an automated software analysis, the role of computed tomography perfusion (CTP) in a real time clinical practice is not well established. We evaluated the clinical significance of a widely accessible and simple visual grading scale of CTP in the anterior circulation of acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT).

METHODS

The single center consecutive CT investigations of AIS patients treated with MT in the anterior circulation have been evaluated retrospectively. ASPECT score and collateral circulation evaluation based on the Maas score were determined. Time to peak parametric maps, derived from CTP, were graded into four categories, from least to most favorable. The primary endpoint was functional outcome evaluated as modified Rankin Scale (mRS) ≤ 2 at 90 days after MT.

RESULTS

We included 318 patients in the analysis; 142 (45%) patients had mRS ≤ 2 after 90 days, mortality rate was 24%. Higher CTP and Maas score were significantly correlated with better clinical outcome (Pearson χ² 25.0 and 37.7, respectively; p < 0.01). Collateral circulation and CTP grades were strongly interrelated (Pearson χ² 78.6; p < 0.01). The CTP grade demonstrated statistically significant independent correlation with the clinical outcome irrespective of the collateral circulation grade, ASPECT score and age (OR 2.5; p = 0.011). The correlation was more pronounced in patients with normal collateral circulation (OR 3.27; p = 0.029).

CONCLUSION

We demonstrated that both visually graded CTP and collateral circulation grade strongly correlated with the clinical outcome of MT in the anterior circulation of AIS patients. Importantly, CTP correlated with the clinical outcome independent of the collateral circulation.

Recent Advances in Targeted Nanotherapies for Ischemic Stroke

Ischemic stroke (IS) is a severe neurological disease caused by the narrowing or occlusion of cerebral blood vessels and is known for high morbidity, disability, and mortality rates. Clinically available treatments of stroke include the surgical removal of the thrombus and thrombolysis with tissue fibrinogen activator. Pharmaceuticals targeting IS are uncommon, and the development of new therapies is hindered by the low bioavailability and stability of many drugs. Nanomedicine provides new opportunities for the development of novel neuroprotective and thrombolytic strategies for the diagnosis and treatment of IS. Numerous nanotherapeutics with different physicochemical properties are currently being developed to facilitate drug delivery by accumulation and controlled release and to improve their restorative properties. In this review, we discuss recent developments in IS therapy, including assisted drug delivery and targeting, neuroprotection through regulation of the neuron environment, and sources of endogenous biomimetic specific targeting. In addition, we discuss the role and neurotoxic effects of inorganic metal nanoparticles in IS therapy. This study provides a theoretical basis for the utilization of nano-IS therapies that may contribute to the development of new strategies for a range of embolic diseases.

Thrombectomy alone versus intravenous alteplase plus thrombectomy in patients with stroke: an open-label, blinded-outcome, randomised non-inferiority trial

BACKGROUND

Whether thrombectomy alone is equally as effective as intravenous alteplase plus thrombectomy remains controversial. We aimed to determine whether thrombectomy alone would be non-inferior to intravenous alteplase plus thrombectomy in patients presenting with acute ischaemic stroke.

METHODS

In this multicentre, randomised, open-label, blinded-outcome trial in Europe and Canada, we recruited patients with stroke due to large vessel occlusion confirmed with CT or magnetic resonance angiography admitted to endovascular centres. Patients were randomly assigned (1:1) via a centralised web server using a deterministic minimisation method to receive stent-retriever thrombectomy alone or intravenous alteplase plus stent-retriever thrombectomy. In both groups, thrombectomy was initiated as fast as possible with any commercially available Solitaire stent-retriever revascularisation device (Medtronic, Irvine, CA, USA). In the combined treatment group, intravenous alteplase (0·9 mg/kg bodyweight, maximum dose 90 mg per patient) was administered as early as possible after randomisation for 60 min with 10% of the calculated dose given as an initial bolus. Personnel assessing the primary outcome were masked to group allocation; patients and treating physicians were not. The primary binary outcome was a score of 2 or less on the modified Rankin scale at 90 days. We assessed the non-inferiority of thrombectomy alone versus intravenous alteplase plus thrombectomy in all randomly assigned and consenting patients using the one-sided lower 95% confidence limit of the Mantel-Haenszel risk difference, with a prespecified non-inferiority margin of 12%. The main safety endpoint was symptomatic intracranial haemorrhage assessed in all randomly assigned and consenting participants. This trial is registered with ClinicalTrials.gov, NCT03192332, and is closed to new participants.

FINDINGS

Between Nov 29, 2017, and May 7, 2021, 5215 patients were screened and 423 were randomly assigned, of whom 408 (201 thrombectomy alone, 207 intravenous alteplase plus thrombectomy) were included in the primary efficacy analysis. A modified Rankin scale score of 0-2 at 90 days was reached by 114 (57%) of 201 patients assigned to thrombectomy alone and 135 (65%) of 207 patients assigned to intravenous alteplase plus thrombectomy (adjusted risk difference -7·3%, 95% CI -16·6 to 2·1, lower limit of one-sided 95% CI -15·1%, crossing the non-inferiority margin of -12%). Symptomatic intracranial haemorrhage occurred in five (2%) of 201 patients undergoing thrombectomy alone and seven (3%) of 202 patients receiving intravenous alteplase plus thrombectomy (risk difference -1·0%, 95% CI -4·8 to 2·7). Successful reperfusion was less common in patients assigned to thrombectomy alone (182 [91%] of 201 vs 199 [96%] of 207, risk difference -5·1%, 95% CI -10·2 to 0·0, p=0·047).

INTERPRETATION

Thrombectomy alone was not shown to be non-inferior to intravenous alteplase plus thrombectomy and resulted in decreased reperfusion rates. These results do not support omitting intravenous alteplase before thrombectomy in eligible patients.

FUNDING

Medtronic and University Hospital Bern.

Predictive Factors for Clinical Outcome After Direct Mechanical Thrombectomy for Anterior Circulation Large Vessel Occlusion Within 4.5 h

Background

Recent trials including DIRECT-MT, DEVT, and SKIP have found that direct mechanical thrombectomy (MT) is equally effective as the combination of MT and intravenous thrombolysis. However, the results of the other trials, namely MR-CLEAN NO-IV and the SWIFT-DIRECT trial have failed to confirm the non-inferiority of direct MT vs. the combination therapy.

Aim

We aimed to identify prognostic factors of direct MT for anterior circulation large vessel occlusion within 4.5 h.

Materials and Methods

Data from January 2018 to January 2022 were retrospectively collected and analyzed. Adult patients with confirmed anterior circulation large vessel occlusion within 4.5 h of onset with baseline NIHSS of ≥6 and baseline ASPECTS of ≥6 treated using direct MT within 6 h were recruited.

Results

A total of 140 patients were enrolled in the study with a median age of 65.5 years [interquartile range (IQR), 59–76.5], median baseline NIHSS of 13.5 (IQR, 11–16), and median baseline ASPECTS of 8 (IQR, 7–8). Direct MT was feasible in all patients (100%). Successful reperfusion (mTICI 2b-3) was achieved in 124/140 patients (88.6%) with a low rate of complications (8/140, 5.7%). Any type of intracranial hemorrhage (ICH) and symptomatic ICH occurred in 44/140 (31.4%) and 5/140 (3.6%), respectively. Overall, a good outcome (mRS 0–2) was achieved in 93/140 (66.4%), and the mortality rate was 9.3% (13/140 patients). Using multivariate analysis, lower age [odds ratio (OR), 0.96; 95% CI, 0.92–1.00; P = 0.05], low baseline NIHSS (OR, 0.82; 95% CI, 0.74–0.92; P = 0.00), and absence of ICH (OR, 0.29; 95% CI, 0.10–0.81; P = 0.02) were independently associated with favorable outcome. Independent predictors of mortality were baseline NIHSS (OR, 1.21; 95% CI, 1.01–1.46; P = 0.04), successful reperfusion (OR, 0.02; 95% CI, 0.00–0.58; P = 0.02), and ICH (OR, 0.12; 95% CI, 0.02–0.75; P = 0.02). Further analysis showed that the median mRS at 90 days was significantly better in the MCA occlusion group compared to the ICA plus M1 occlusion group [1 (IQR 0–3) vs. 2 (IQR 1–4); P = 0.05].

Conclusions

Our findings suggest that direct thrombectomy may be an adequate clinical option for younger patients (≤70) experiencing proximal middle artery occlusion within 4.5 h and who have low baseline NIHSS (≤14).

Role of Intravenous Thrombolytics Prior to Endovascular Thrombectomy

Intravenous thrombolytics and endovascular thrombectomy for ischemic stroke have evolved in parallel. However, the best approach to combine these reperfusion therapies in patients eligible for both strategies remains uncertain. Initial randomized trials of endovascular thrombectomy included administration of intravenous thrombolytics to all eligible patients. However, whether that is of net benefit has been questioned and parallels drawn with treatment of ST-segment-elevation myocardial infarction, where intravenous thrombolytics are only given if first medical contact to percutaneous intervention is expected to be >90 minutes. Six randomized trials of a direct thrombectomy approach versus intravenous thrombolytics followed by endovascular thrombectomy have now reported their results. With exception of a minority of patients in one trial, the trials all used alteplase rather than potentially more effective tenecteplase. This review examines the current state of evidence and implications for clinical practice. Importantly, these trials only apply to patients who present to a hospital with immediate access to endovascular thrombectomy and are not relevant to patients who receive thrombolytic and are then transferred to an endovascular-capable hospital. Although 2 of the 6 randomized trials met their prespecified noninferiority margin, these margins were large compared with the absolute benefit of alteplase. Overall, functional outcome was similar, with slight trends favoring bridging thrombolytics and a significant increase in final reperfusion. Symptomatic hemorrhage was increased by ≈1.8% in the bridging group but death was nonsignificantly lower. The workflow in direct thrombectomy trials involved delaying thrombolytic administration until eligibility for thrombectomy and the trials was established and randomization completed. This reduced the time available for thrombolytics to occur prethrombectomy compared with standard practice. We conclude that, pending individual-patient data meta-analyses, intravenous thrombolytics retain an important role alongside endovascular thrombectomy. Further efforts to accelerate and enhance reperfusion with thrombolytics and perform individual patient-level pooled subgroup analyses are warranted.

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.

Bridging Thrombolysis versus Direct Mechanical Thrombectomy in Stroke Due to Basilar Artery Occlusion

Background and Purpose

Mechanical thrombectomy (MT) is an effective treatment for patients with basilar artery occlusion (BAO) acute ischemic stroke. It remains unclear whether bridging intravenous thrombolysis (IVT) prior to MT confers any benefit. This study compared the outcomes of acute BAO patients who were treated with direct MT versus combined IVT plus MT.

Methods

This multicenter retrospective cohort study included patients who were treated for acute BAO from eight comprehensive stroke centers between January 2015 and December 2019. Patients received direct MT or combined bridging IVT plus MT. Primary outcome was favorable functional outcome defined as modified Rankin Scale 0–3 measured at 90 days. Secondary outcome measures included mortality and symptomatic intracranial hemorrhage (sICH).

Results

Among 322 patients, 127 (39.4%) patients underwent bridging IVT followed by MT and 195 (60.6%) underwent direct MT. The mean±standard deviation age was 67.5±14.1 years, 64.0% were male and median National Institutes of Health Stroke Scale was 16 (interquartile range, 8 to 25). At 90-day, the rate of favorable functional outcome was similar between the bridging IVT and direct MT groups (39.4% vs. 34.4%, P=0.361). On multivariable analyses, bridging IVT was not as Comorbidisociated with favorable functional outcome, mortality or sICH. In subgroup analyses, patients with underlying atherosclerosis treated with bridging IVT compared to direct MT had a higher rate of favorable functional outcome at 90 days (37.2% vs. 15.5%, P=0.013).

Conclusions

Functional outcomes were similar in BAO patients treated with bridging IVT versus direct MT. In the subgroup of patients with underlying large-artery atherosclerosis stroke mechanism, bridging IVT may potentially confer benefit and this warrants further investigation.

Dodging blood brain barrier with "nano" warriors: Novel strategy against ischemic stroke

Ischemic stroke (IS) is one of the leading causes of death and disability resulting in inevitable burden globally. Ischemic injury initiates cascade of pathological events comprising energy dwindling, failure of ionic gradients, failure of blood brain barrier (BBB), vasogenic edema, calcium over accumulation, excitotoxicity, increased oxidative stress, mitochondrial dysfunction, inflammation and eventually cell death. In spite of such complexity of the disease, the only treatment approved by US Food and Drug Administration (FDA) is tissue plasminogen activator (t-PA). This therapy overcome blood deficiency in the brain along with side effects of reperfusion which are responsible for considerable tissue injury. Therefore, there is urgent need of novel therapeutic perspectives that can protect the integrity of BBB and salvageable brain tissue. Advancement in nanomedicine is empowering new approaches that are potent to improve the understanding and treatment of the IS. Herein, we focus nanomaterial mediated drug delivery systems (DDSs) and their role to bypass and cross BBB especially via intranasal drug delivery. The various nanocarriers used in DDSs are also discussed. In a nut shell, the objective is to provide an overview of use of nanomedicine in the diagnosis and treatment of IS to facilitate the research from benchtop to bedside.

Initial Stress Hyperglycemia Is Associated With Malignant Cerebral Edema, Hemorrhage, and Poor Functional Outcome After Mechanical Thrombectomy

BACKGROUND

Malignant cerebral edema (MCE) and intracranial hemorrhage (ICH) are associated with poor neurological outcomes despite revascularization after mechanical thrombectomy (MT). The factors associated with the development of MCE and ICH after MT are not well understood.

OBJECTIVE

To determine periprocedural factors associated with MCE, ICH, and poor functional outcome.

METHODS

We retrospectively analyzed anterior cerebral circulation large vessel occlusion cases that underwent MT from 2012 to 2019 at a single Comprehensive Stroke Center. Multivariate logistic regression analyses were performed to determine significant predictors of MCE, ICH, and poor functional outcome (modified Rankin Scale, 3-6) at 90 d.

RESULTS

Four hundred patients were included. Significant independent predictors of MCE after MT included initial stress glucose ratio (iSGR) (odds ratio [OR], 14.26; 95% CI, 3.82-53.26; P < .001), National Institutes of Health Stroke Scale (NIHSS) (OR, 1.10; 95% CI, 1.03-1.18; P = .008), internal carotid artery compared with M1 or M2 occlusion, and absence of successful revascularization (OR, 0.16; 95% CI, 0.06-0.44; P < .001). Significant independent predictors of poor functional outcome included MCE (OR, 7.47; 95% CI, 2.20-25.37; P = .001), iSGR (OR, 5.15; 95% CI, 1.82-14.53; P = .002), ICH (OR, 4.77; 95% CI, 1.20-18.69; P = .024), NIHSS (OR, 1.10; 95% CI, 1.05-1.16; P < .001), age (OR, 1.04; 95% CI, 1.03-1.07; P < .001), and thrombolysis in cerebral infarction 2C/3 recanalization (OR, 0.12; 95% CI, 0.05-0.29; P < .001).

CONCLUSION

Elevated iSGR significantly increases the risk of MCE and ICH and is an independent predictor of poor functional outcome. Thrombolysis in cerebral infarction 2C/3 revascularization is associated with reduced risk of MCE, ICH, and poor functional outcome. Whether stress hyperglycemia represents a modifiable risk factor is uncertain, and further investigation is warranted.

Full Reperfusion Without Functional Independence After Mechanical Thrombectomy in the Anterior Circulation : Performance of Prediction Models Before Versus After Treatment Initiation

BACKGROUND AND PURPOSE

Prediction of futile recanalization (FR), i.e. failure of long-term functional independence despite full reperfusion in mechanical thrombectomy (MT), is instrumental in patients undergoing endovascular therapy.

METHODS

Retrospective single-center analysis of patients treated for anterior circulation LVO ensuing successful MT (mTICI 2c-3) between January 2014 and April 2019. FR was defined as modified Rankin Scale (mRS) 90 days after stroke onset > 2 or mRS > pre-stroke mRS. Multivariable analysis was performed with variables available before treatment initiation regarding their association with FR. Performance of the regression model was then compared with a model including parameters available after MT.

RESULTS

Successful MT was experienced by 549/1146 patients in total. FR occurred in 262/549 (47.7%) patients. Independent predictors of FR were male sex, odds ratio (OR) with 95% confidence interval (CI) 1.98 (1.31-3.05, p 0.001), age (OR 1.05, CI 1.03-1.07, p < 0.001), NIHSS on admission (OR 1.10, CI 1.06-1.13, p < 0.001), pre-stroke mRS (OR 1.22, CI 1.03-1.46, p 0.025), neutrophile-lymphocyte ratio (OR 1.03, CI 1.00-1.06, p 0.022), baseline ASPECTS (OR 0.77, CI 0.68-0.88, p < 0.001), and absence of bridging i.v. lysis (OR 1.62, 1.09-2.42, p 0.016). The prediction model's Area Under the Curve was 0.78 (CI 0.74-0.82) and increased with parameters available after MT to 0.86 (CI 0.83-0.89) with failure of early neurological improvement being the most important predictor of FR (OR 15.0, CI 7.2-33.8).

CONCLUSION

A variety of preinterventional factors may predict FR with substantial certainty, but the prediction model can still be improved by considering parameters only available after MT, in particular early neurological improvement.

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.

Effect of Intravenous Thrombolysis on Clot Survival during Mechanical Thrombectomy in Acute Large Vessel Occlusion Strokes

BACKGROUND

The benefit of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) in patients with large vessel occlusion (LVO) stroke is uncertain. Conventional metrics of final modified thrombolysis in cerebral ischemia (mTICI) score and 90-d modified Rankin Scale may be insensitive to IVT effects on procedural complexity and duration.

OBJECTIVE

To study the effect of IVT prior to MT on clot survival.

METHODS

We performed a single-center retrospective analysis of 257 acute stroke patients with LVO undergoing MT and analyzed the effect of IVT prior to MT using a novel, pass-by-pass clot survival methodology.

RESULTS

The use of IVT was associated with a significantly lower number of passes to attain mTICI 2B or greater (P = .002) or mTICI 3 (P = .039) reperfusion. The number of patients who achieved mTICI 2B or greater after the first pass was significantly higher in the IVT group (P = .003). This increased rate of reperfusion persisted into subsequent passes.

CONCLUSION

IVT prior to MT reduces the number of thrombectomy passes required to achieve mTICI 2B or mTICI 3 reperfusion. This information should be considered as the merits of IVT prior to MT are debated.

Difference of Thrombus Location between Initial Noninvasive Vascular Image and First DSA Findings in Mechanical Thrombectomy for Intracranial Large Vessel Occlusion: Post Hoc Analysis of the SKIP Study

In patients who undergo mechanical thrombectomy for intracranial large vessel occlusion, the occluded site is sometimes distal to the site shown in the initial vascular imaging. We investigated the factors related to the change in the occluded site between the sequential imagings. The 203 patients in the SKIP study were reviewed retrospectively. Magnetic resonance angiography (MRA) or computed tomography angiography (CTA) was used to assess the occluded site. The occluded site shown in the cerebral angiography appeared to be distal to the occluded site shown in the initial vascular imaging in 55 patients (group A). The location of the occluded site in the remaining 148 patients did not change between the sequential imagings (group B). MRA was used more often than CTA in group A (54 MRA, 1 CTA; P <0.01). Patients with middle cerebral artery (M1) occlusion were more likely to show change of the occluded site than patients with internal carotid artery (ICA) occlusion (M1: 38%, ICA: 9%; P <0.01). The number of patients who received intravenous recombinant tissue plasminogen activator did not differ between the two groups (group A: 54%, group B: 49%; P = 0.5). In patients with acute intracranial large vessel occlusion who require mechanical thrombectomy, physicians should be aware that the location of the thrombus may be distal to the occluded site shown in the initial vascular imaging, particularly in patients with M1 occlusion shown by MRA.

Imaging selection for reperfusion therapy in acute ischemic stroke beyond the conventional time window

Originally, the efficacy of acute ischemic stroke treatment with thrombolysis or thrombectomy was only proven in narrow time windows of, respectively, 4.5 and 6 h after onset. Introducing imaging-based selection beyond non-contrast enhanced computed tomography has expanded the treatment window, focusing on presumed tissue status rather than solely on time after stroke onset. Different mismatch concepts have been adopted in clinical practice to select patients in the extended and unknown time window based on findings from randomized controlled trials. Since various concepts exist that can identify patients likely to benefit from reperfusion strategies, clinicians may wonder which imaging modality may be preferred in the emergency setting. In this review, we will discuss the different mismatch concepts and their practical implementation for patient selection for thrombolysis or thrombectomy, beyond the conventional time window.

Regional Disparity of Reperfusion Therapy for Acute Ischemic Stroke in Japan: A Retrospective Analysis of Nationwide Claims Data from 2010 to 2015

Background

We aimed to determine whether a regional disparity exists in usage of reperfusion therapy (intravenous recombinant tissue plasminogen activator [IV rt‐PA] and endovascular thrombectomy [EVT]) and post‐reperfusion 30‐day mortality in patients with acute ischemic stroke, and which regional factors are associated with their usage.

Methods and Results

We retrospectively investigated 69 948 patients (mean age±SD, 74.9±12.0 years; women, 41.4%) with acute ischemic stroke treated with reperfusion therapy between April 2010 and March 2016 in Japan using nationwide claims data. Regional disparity was evaluated using Gini coefficients for age‐ and sex‐adjusted usage of reperfusion therapy and 30‐day post‐reperfusion in‐hospital death ratio in 47 administrative regions. The association between regional factors and reperfusion therapy usage was evaluated with fixed‐effects regression models. During the study period, Gini coefficients showed low inequality (0.11–0.15) for use of IV rt‐PA monotherapy and IV rt‐PA and/or EVT and extreme inequality (0.49) for EVT usage in 2010, which became moderate inequality (0.25) by 2015. The densities of stroke centers and endovascular specialists, as well as market concentration, were associated with increased usage of reperfusion therapy whereas the proportion of rural residents and delayed ambulance transport were negatively associated with usage. Inequality in the standardized death ratio after EVT was extreme (0.86) in 2010 but became moderate (0.29) by 2015; inequality was low to moderate (0.17–0.23) for IV rt‐PA monotherapy and IV rt‐PA and/or EVT.

Conclusions

Scrutinizing existing data sources revealed regional disparity in reperfusion therapy for acute ischemic stroke and its associated regional factors in Japan.

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.

Endovascular Thrombectomy preceded by intravenous Alteplase versus endovascular Thrombectomy alone in Han Chinese patients treated for acute ischemic stroke with large vessel occlusion: a single-center retrospective analysis

BACKGROUND

The American Heart Association/ American Stroke Association and the Chinese Stroke Association guidelines are recommending intravenous alteplase intervention before endovascular thrombectomy if patients are eligible to do so but the benefits of endovascular thrombectomy are different in Chinese patients with stroke than those of the white patients. The objective of the study was to compare outcomes of patients with acute ischemic stroke treated with endovascular thrombectomy with intravenous alteplase against those treated with endovascular thrombectomy alone.

METHODS

A report is a retrospective analysis of comparing demographics, imaging, clinical and adverse outcomes in the Han Chinese patient who underwent mechanical thrombectomy for acute ischemic stroke with large vessel occlusion, with or without preceding intravenous alteplase administration. Patients with terminus and non-terminus intracranial occlusions and ≤ 2 points neurologic deficit underwent endovascular thrombectomy preceded by 0.9 mg/ kg intravenous alteplase (ET cohort, n = 184) and those who had contra-indication for intravenous alteplase were treated with endovascular thrombectomy alone (EA cohort, n = 141).

RESULTS

The most common procedural complications were embolization into new territory (p = 0.866) and uneventful artery vasospasm (p = 0.712). Insignificant differences were reported for any procedural complications (p = 0.991), imaging outcomes, the modified Rankin scale score (p = 0.663), and death (28 vs. 24, p = 0.761) within 90 days between patients of both cohorts. At the discharge of the hospital, the National Institutes of Health Stroke Scale scores of patients of the ET cohort were lower than those of the EA cohort (8.58 ± 3.79 vs. 10.23 ± 4.97, p = 0.003). The Barthel Index of survivors at 90 days after endovascular thrombectomy was higher for patients of the ET cohort than those of the EA cohort (87.47 ± 12.58 vs. 84.01 ± 13.47, p = 0.032). The most common adverse effect was asymptomatic intracranial hemorrhage (p = 0.297). Insignificant differences were reported for adverse effects after thrombectomy between survivors of both cohorts.

CONCLUSIONS

Outcome measures in Han Chinese patients with acute ischemic stroke treated with endovascular thrombectomy alone were statistically the same as those treated with endovascular thrombectomy plus intravenous alteplase.

LEVEL OF EVIDENCE

Iii TECHNICAL EFFICACY STAGE: 4.

Acute Recanalization of Large Vessel Occlusion in the Anterior Circulation Stroke: Is Mechanical Thrombectomy Alone Better in Patients over 80 Years of Age? Findings from a Retrospective Observational Study

Real-world data report worse 3-month clinical outcomes in elderly patients with acute ischemic stroke (AIS) treated with mechanical thrombectomy (MT). The aim was to identify factors influencing clinical outcome in elderly patients with anterior circulation AIS treated with MT (±intravenous thrombolysis (IVT)). In a retrospective, monocentric study, analysis of prospectively collected data of 138 patients (≥80 years) was performed. IVT was an independent negative predictor (OR 0.356; 95% CI: 0.134–0.942) and female sex an independent positive predictor (OR 4.179, 95% CI: 1.300–13.438) of 3-month good clinical outcome (modified Rankin scale 0–2). Female sex was also an independent negative predictor of 3-month mortality (OR 0.244, 95% CI: 0.100–0.599). Other independent negative predictors of 3-month good clinical outcome were older age, lower pre-stroke self-sufficiency, more severe neurological deficit and longer procedural intervals. Mortality was also independently predicted by longer procedural interval and by the occurrence of symptomatic intracerebral hemorrhage (p < 0.05 in all cases). Our results demonstrated, that in patients aged ≥80 years with anterior circulation AIS undergoing MT (±IVT), IVT reduced the chance of 3-month good clinical outcome and female sex was associated with a greater likelihood of 3-month good clinical outcome and lower probability of 3-month mortality.

Do methods of hospital pre-alerts influence the on-scene times for acute pre-hospital stroke patients? A retrospective observational study

INTRODUCTION

Stroke is one of the leading causes of death and disability worldwide. The ambulance service is often the first medical service to reach an acute stroke patient, and due to the time-critical nature of stroke, a time-critical assessment and rapid transport to a hyper acute stroke unit are essential. As stroke services have been centralised, different hospitals have implemented different pre-alert admission policies that may affect the on-scene time of the attending ambulance crew. The aim of this study is to investigate if the different pre-alert admission policies affect time on scene.

METHOD

The current study is a retrospective quantitative observational study using data routinely collected by North East Ambulance Service NHS Foundation Trust. The time on scene was divided into two variables; group one was a telephone pre-alert in which a telephone discussion with the receiving hospital is required before they accept admission of the patient. Group two was a radio-style pre-alert in which the attending clinician makes an autonomous decision on the receiving hospital and alerts them via a short radio message of the incoming patient. These times were then compared to identify if there was any difference between them.

RESULTS

Data on 927 patients over a three-month period, from October to December 2019, who had received the full stroke bundle of care, were within the thrombolysis window and recorded as a stroke by the attending clinician, were split into the variable groups and reported on. The mean time on scene for a telephone call pre-alert was 33 minutes and 19 seconds, with a standard deviation of 13 minutes and 8 seconds. The mean on-scene time for a radio pre-alert was 28 minutes and 24 seconds, with a standard deviation of 11 minutes and 51 seconds.

CONCLUSION

A pre-alert given via radio instead of via telephone is shown to have a mean time saving of 4 minutes and 55 seconds, representing an important decrease in time which could be beneficial to patients.

Bridging versus direct endovascular therapy in basilar artery occlusion

BACKGROUND

We evaluated safety and efficacy of intravenous recombinant tissue Plasminogen Activator plus endovascular (bridging) therapy compared with direct endovascular therapy in patients with ischaemic stroke due to basilar artery occlusion (BAO).

METHODS

From a national prospective registry of endovascular therapy in acute ischaemic stroke, we selected patients with BAO. We compared bridging and direct endovascular therapy evaluating vessel recanalisation, haemorrhagic transformation at 24-36 hours; procedural complications; and functional outcome at 3 months according to the modified Rankin Scale. We ran logistic and ordinal regression models adjusting for age, sex, National Institutes of Health Stroke Scale (NIHSS), onset-to-groin-puncture time.

RESULTS

We included 464 patients, mean(±SD) age 67.7 (±13.3) years, 279 (63%) males, median (IQR) NIHSS=18 (10-30); 166 (35%) received bridging and 298 (65%) direct endovascular therapy. Recanalisation rates and symptomatic intracerebral haemorrhage were similar in both groups (83% and 3%, respectively), whereas distal embolisation was more frequent in patients treated with direct endovascular therapy (9% vs 3%; p=0.009). In the whole population, there was no difference between bridging and direct endovascular therapy regarding functional outcome at 3 months (OR=0.79; 95% CI=0.55 to 1.13). However, in patients with onset-to-groin-puncture time ≤6 hours, bridging therapy was associated with lower mortality (OR=0.53; 95% CI=0.30 to 0.97) and a shift towards better functional outcome in ordinal analysis (OR=0.65; 95% CI=0.42 to 0.98).

CONCLUSIONS

In ischaemic stroke due to BAO, when endovascular therapy is initiated within 6 hours from symptoms onset, bridging therapy resulted in lower mortality and better functional outcome compared with direct endovascular therapy.

Optimizing Emergency Stroke Transport Strategies Using Physiological Models

Supplemental Digital Content is available in the text.

The criteria for choosing between drip and ship and mothership transport strategies in emergency stroke care is widely debated. Although existing data-driven probability models can inform transport decision-making at an epidemiological level, we propose a novel mathematical, physiologically derived framework that provides insight into how patient characteristics underlying infarct core growth influence these decisions.

Influence of prior intravenous thrombolysis on outcome after failed mechanical thrombectomy: ETIS registry analysis

BACKGROUND

Despite constant improvements in recent years, sufficient reperfusion after mechanical thrombectomy (MT) is not reached in up to 15% of patients with large vessel occlusion stroke (LVOS). The outcome of patients with unsuccessful reperfusion after MT especially after intravenous thrombolysis (IVT) use is not known. We investigated the influence of initial IVT in this particular group of patients with failed intracranial recanalization.

METHODS

We conducted a retrospective analysis of the Endovascular Treatment in Ischemic Stroke (ETIS) registry from January 2015 to December 2019. Patients presenting with LVOS of the anterior circulation and final modified Thrombolysis in Cerebral Infarction score (mTICI) of 0, 1 or 2a were included. Posterior circulation, isolated cervical carotid occlusions and successful reperfusions (mTICI 2b, 2c or 3) were excluded. The primary endpoint was favorable outcome (modified Rankin Scale score of 0-2) after 3 months. Secondary endpoints were safety outcomes including mortality, any intracranial hemorrhage (ICH), parenchymal hematoma (PH) and symptomatic intracranial hemorrhage (sICH) rates.

RESULTS

Among 5076 patients with LVOS treated with MT, 524 patients with insufficient recanalization met inclusion criteria, of which 242 received IVT and 282 did not. Functional outcome was improved in the MT+IVT group compared with the MT alone group, although the difference did not reach statistical significance (23.0% vs 12.9%; adjusted OR=1.82; 95% CI 0.98 to 3.38; p=0.058). However, 3 month mRS shift analysis showed a significant benefit of IVT (adjusted OR=1.68; 95% CI 1.56 to 6.54). ICH and sICH rates were similar in both groups, although PH rate was higher in the MT+IVT group (adjusted OR=3.20; 95% CI 1.56 to 6.54).

CONCLUSIONS

Among patients with LVOS in the anterior circulation and unsuccessful MT, IVT was associated with improved functional outcome even after unsuccessful MT. Despite recent trials questioning the place of IVT in the LVOS reperfusion strategy, these findings emphasize a subgroup of patients still benefiting from IVT.

Thrombolytic strategies for ischemic stroke in the thrombectomy era

Twenty-five years ago, intravenous thrombolysis has revolutionized the care of patients with acute ischemic stroke. Since 2015, randomized clinical trials have demonstrated that mechanical thrombectomy improves functional outcome in stroke patients over intravenous thrombolysis alone. More recently, three randomized clinical trials have suggested that mechanical thrombectomy alone is noninferior to a combined strategy with both intravenous thrombolysis and mechanical thrombectomy. In the present review, we will present the last clinical and preclinical studies on the use of thrombolysis in stroke patients in the modern thrombectomy era. At the cost of a potential increased risk of hemorrhagic transformation, thrombolysis may promote arterial recanalization before thrombectomy, improve the rate of successful recanalization after thrombectomy, and restore microcirculation patency downstream of the main thrombus. Besides, new thrombolytic strategies targeting tissue-type plasminogen activator resistant thrombi are being developed, which could strengthen the beneficial effects of thrombolysis without carrying additional pro-hemorrhagic effects. For instance, tenecteplase has shown improved rate of recanalization compared with tissue-type plasminogen activator (alteplase). Beyond fibrinolysis, DNA- and von Willebrand factor-targeted thrombolytic strategies have shown promising results in experimental models of ischemic stroke. New combined strategies, improved thrombolytics, and dedicated clinical trials in selected patients are eagerly awaited to further improve functional outcome in stroke.

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.

Safety and Outcomes of Thrombectomy in Ischemic Stroke With vs Without IV Thrombolysis

OBJECTIVE

To test the hypothesis that IV thrombolysis (IVT) treatment before endovascular thrombectomy (EVT) is associated with better outcomes in patients with anterior circulation large artery occlusion (LAO) stroke, we examined a large real-world database, the Safe Implementation of Treatment in Stroke-International Stroke Thrombectomy Register (SITS-ISTR).

METHODS

We identified centers recording ≥10 consecutive patients in the SITS-ISTR, with at least 70% available modified Rankin Scale (mRS) scores at 3 months during 2014 to 2019. We defined LAO as intracranial internal carotid artery, first and second segment of middle cerebral artery, and first segment of anterior cerebral artery. Main outcomes were functional independence (mRS score 0-2) and death at 3 months and symptomatic intracranial hemorrhage (SICH) per modified SITS-Monitoring Study. We performed propensity score-matched (PSM) and multivariable logistic regression analyses.

RESULTS

Of 6,350 patients from 42 centers, 3,944 (62.1%) received IVT. IVT + EVT-treated patients had less frequent atrial fibrillation, ongoing anticoagulation, previous stroke, heart failure, and prestroke disability. PSM analysis showed that IVT + EVT-treated patients had a higher rate of functional independence than patients treated with EVT alone (46.4% vs 40.3%, p < 0.001) and a lower rate of death at 3 months (20.3% vs 23.3%, p = 0.035). SICH rates (3.5% vs 3.0%, p = 0.42) were similar in both groups. Multivariate adjustment yielded results consistent with PSM.

CONCLUSION

Pretreatment with IVT was associated with favorable outcomes in EVT-treated LAO stroke in the SITS-ISTR. These findings, while indicative of international routine clinical practice, are limited by observational design, unmeasured confounding, and possible residual confounding by indication.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that IVT before EVT increases the probability of functional independence at 3 months compared to EVT alone.

Prediction of Early Recanalization after Intravenous Thrombolysis in Patients with Large-Vessel Occlusion

Background and Purpose

We aimed to develop a model predicting early recanalization after intravenous tissue plasminogen activator (t-PA) treatment in large-vessel occlusion.

Methods

Using data from two different multicenter prospective cohorts, we determined the factors associated with early recanalization immediately after t-PA in stroke patients with large-vessel occlusion, and developed and validated a prediction model for early recanalization. Clot volume was semiautomatically measured on thin-section computed tomography using software, and the degree of collaterals was determined using the Tan score. Follow-up angiographic studies were performed immediately after t-PA treatment to assess early recanalization.

Results

Early recanalization, assessed 61.0±44.7 minutes after t-PA bolus, was achieved in 15.5% (15/97) in the derivation cohort and in 10.5% (8/76) in the validation cohort. Clot volume (odds ratio [OR], 0.979; 95% confidence interval [CI], 0.961 to 0.997; P=0.020) and good collaterals (OR, 6.129; 95% CI, 1.592 to 23.594; P=0.008) were significant factors associated with early recanalization. The area under the curve (AUC) of the model including clot volume was 0.819 (95% CI, 0.720 to 0.917) and 0.842 (95% CI, 0.746 to 0.938) in the derivation and validation cohorts, respectively. The AUC improved when good collaterals were added (derivation cohort: AUC, 0.876; 95% CI, 0.802 to 0.950; P=0.164; validation cohort: AUC, 0.949; 95% CI, 0.886 to 1.000; P=0.036). The integrated discrimination improvement also showed significantly improved prediction (0.097; 95% CI, 0.009 to 0.185; P=0.032).

Conclusions

The model using clot volume and collaterals predicted early recanalization after intravenous t-PA and had a high performance. This model may aid in determining the recanalization treatment strategy in stroke patients with large-vessel occlusion.

Impact of intravenous alteplase on sub-angiographic emboli in high-resolution diffusion-weighted imaging following successful thrombectomy

Objective

Thrombus microfragmentation causing peripheral emboli (PE) during mechanical thrombectomy (MT) may modulate treatment effects, even in cases with successful reperfusion. This study aims to investigate whether intravenous alteplase is of potential benefit in reducing PE after successful MT.

Methods

Patients from a prospective study treated at a tertiary care stroke center between 08/2017 and 12/2019 were analyzed. The main inclusion criterion was successful reperfusion after MT (defined as expanded thrombolysis in cerebral infarction (eTICI) scale ≥ 2b50) of large vessel occlusion anterior circulation stroke. All patients received a high-resolution diffusion-weighted imaging (DWI) follow-up 24 h after MT for PE detection. Patients were grouped as “direct MT” (no alteplase) or as MT plus additional intravenous alteplase. The number and volume of ischemic core lesions and PE were then quantified and analyzed.

Results

Fifty-six patients were prospectively enrolled. Additional intravenous alteplase was administered in 46.3% (26/56). There were no statistically significant differences of PE compared by groups of direct MT and additional intravenous alteplase administration regarding mean numbers (12.1, 95% CI 8.6–15.5 vs. 11.1, 95% CI 7.0–15.1; p = 0.701), and median volume (0.70 mL, IQR 0.21–1.55 vs. 0.39 mL, IQR 0.10–1.62; p = 0.554). In uni- and multivariable linear regression analysis, higher eTICI scores were significantly associated with reduced PE, while the administration of alteplase was neither associated with numbers nor volume of peripheral emboli. Additional alteplase did not alter reperfusion success.

Conclusions

Intravenous alteplase neither affects the number nor volume of sub-angiographic DWI-PE after successful endovascular reperfusion. In the light of currently running randomized trials, further studies are warranted to validate these findings.

Key Points

• Thrombus microfragmentation during endovascular stroke treatment may cause peripheral emboli that are only detectable on diffusion-weighted imaging and may directly compromise treatment effects.

• In this prospective study, the application of intravenous alteplase did not influence the occurrence of peripheral emboli detected on high-resolution diffusion-weighted imaging.

• A higher degree of recanalization was associated with a reduced number and volume of peripheral emboli and better functional outcome, while contrariwise, peripheral emboli did not modify the effect of recanalization on modified Rankin Scale scores at day 90.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-07980-0.

Endovascular therapy with or without intravenous thrombolysis in acute stroke with tandem occlusion

BACKGROUND

Endovascular therapy (EVT) is effective and safe in patients with tandem occlusion. The benefit of intravenous thrombolysis (IVT) prior to EVT in acute tandem occlusion is debatable.

OBJECTIVE

To compare EVT alone with EVT plus IVT in patients with acute ischemic stroke due to anterior circulation tandem occlusions.

METHODS

This is an individual patient pooled analysis of the Thrombectomy In TANdem lesions (TITAN) and Endovascular Treatment in Ischemic Stroke (ETIS) Registries. Patients were divided into two groups based on prior IVT treatment: (1) IVT+ group, which included patients who received IVT prior to EVT, (2) IVT- group, which included patients who did not receive IVT prior to EVT. Propensity score (inverse probability of treatment weighting (IPTW)) was used to reduce baseline between-group differences. The primary outcome was favorable outcome-that is, modified Rankin Scale (mRS) score 0 to 2 at 90 days.

RESULTS

Overall, 602 consecutive patients with an acute stroke with tandem occlusion were included (380 and 222 in the bridging therapy and EVT alone groups, respectively). Onset to imaging time was shorter in the IVT+ group (median 103 vs 140 min). In contrast, imaging to puncture time was longer in the IVT+ group (median 107 vs 91 min). In IPTW analysis, the IVT+ group had higher odds of favorable outcome, excellent outcome (90-day mRS score 0-1), and successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2b/3 at the end of EVT). There was no difference in the risk of significant hemorrhagic complications between groups. In secondary analysis of patients treated with acute cervical internal carotid artery stenting, bridging therapy was associated with higher odds of favorable outcome and lower odds of mortality at 90 days.

CONCLUSIONS

Our results suggest that bridging therapy in patients with acute ischemic stroke due to anterior tandem occlusion is safe and may improve functional outcome, even in the setting of acute cervical internal carotid artery stenting during EVT.

Intravenous tPA Delays Door-To-Puncture Time in Acute Ischemic Stroke with Large Vessel Occlusion

OBJECTIVE

Although intravenous thrombolysis (IVT) is recommended among acute ischemic stroke (AIS) patients secondary to large vessel occlusion (LVO) undergoing mechanical thrombectomy (MT), time delays with bridging therapy (IVT prior to MT) and its potential benefit remains unclear. We compared the time delays and clinical outcomes among AIS SECONDARY TO LVO patients treated with bridging therapy or direct MT (dMT) at a comprehensive stroke center (CSC).

METHODS

We performed a retrospective analysis of prospectively collected data of AIS secondary to LVO patients admitted between 2012 and 2017 at a large volume CSC. AIS secondary to LVO patients arriving directly from field to CSC within 4.5 h were included. Demographic characteristics, clinical and radiological data, treatment and procedural information were extracted and analyzed.

RESULTS

Among 777 AIS secondary to LVO patients treated with MT, 237 patients (156 dMT, 81 bridging therapy) were included. Mean age was 70.3 year-old, median NIHSS score was 18, and door-to-needle time was 40 min (IQR 31-56 min). The median door-to-puncture (DTP) time was 22 min longer in bridging therapy group in comparison to dMT group, 74 vs 52 min (p<0.001). Additionally, no difference was observed between the groups for successful recanalization or functional independence.

CONCLUSION

At a large volume CSC, bridging therapy (vs. dMT) was observed to have a longer DTP time without any difference in successful recanalization or clinical outcomes.

Low-Dose vs. Standard-Dose Intravenous Alteplase in Bridging Therapy Among Patients With Acute Ischemic Stroke: Experience From a Stroke Center in Vietnam

Background: To date, the role of bridging intravenous thrombolysis before mechanical thrombectomy (MTE) is controversial but still recommended in eligible patients. Different doses of intravenous alteplase have been used for treating patients with acute ischemic stroke from large-vessel occlusion (LVO-AIS) in Asia, largely due to variations in the risks for intracerebral hemorrhage (ICH) and treatment affordability. Uncertainty exists over the potential benefits of treating low-dose alteplase, as opposed to standard-dose alteplase, prior to MTE among patients with LVO-AIS. Aim: The aim of the study was to compare outcomes of low- vs. standard-dose of bridging intravenous alteplase before MTE among LVO-AIS patients. Methods: We performed a retrospective analysis of LVO-AIS patients who were treated with either 0.6 mg/kg or 0.9 mg/kg alteplase prior to MTE at a stroke center in Northern Vietnam. Multivariable logistic regression models, accounting for potential confounding factors including comorbidities and clinical factors (e.g., stroke severity), were used to compare the outcomes between the two groups. Our primary outcome was functional independence at 90 days following stroke (modified Rankin score; mRS ≤ 2). Secondary outcomes included any ICH incidence, early neurological improvement, recanalization rate, and 90-day mortality. Results: We analyzed data of 107 patients receiving bridging therapy, including 73 with low-dose and 34 with standard-dose alteplase before MTE. There were no statistically significant differences between the two groups in functional independence at 90 days (adjusted OR 1.02, 95% CI 0.29-3.52) after accounting for potential confounding factors. Compared to the standard-dose group, patients with low-dose alteplase before MTE had similar rates of successful recanalization, early neurological improvement, 90-day mortality, and ICH complications. Conclusion: In the present study, patients with low-dose alteplase before MTE were found to achieve comparable clinical outcomes compared to those receiving standard-dose alteplase bridging with MTE. The findings suggest potential benefits of low-dose alteplase in bridging therapy for Asian populations, but this needs to be confirmed by further clinical trials.