The benefits of intravenous thrombolysis relate to the site of baseline arterial occlusion in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET)

Clinical evidence comparing bridging and direct endovascular thrombectomy: progress and controversies

Clinical evidence comparing bridging endovascular thrombectomy (bEVT) with intravenous thrombolysis and direct endovascular thrombectomy (dEVT) without thrombolysis for patients with acute ischemic stroke (AIS) presented directly to an EVT-capable center is overwhelming but inconsistent. This study aimed to analyze the progress and controversies in clinical evidence based on current meta-analyses. Three databases, including MEDLINE, EMBASE, and the Cochrane Library, were searched. Relevant data were extracted and reviewed from the pooled studies. The Assessment of Multiple Systematic Review (AMSTAR-2) was used for quality assessment. Twenty-five meta-analyses were finally included. There were 56% (14/25) from Asian countries, 20% (5/25) from North America, and 24% (6/25) from Europe. The majority (72%, 18/25) of evidence arose in a short period from 2020 to 2022 with the serial publication of four randomized controlled trials (RCTs). Among the 25 meta-analyses, 11 pooled at least three RCTs but there is substantial overlap among seven (five recruited the same four RCTs solely and two recruited the same three RCTs solely). Meanwhile, quality rating based on AMSTAR-2 showed 16 'high' rated studies (64%). For functional independence, 40% (10/25) of studies favored bEVT and 60% showed neutral results. For symptomatic intracerebral hemorrhage, most studies (82.6%, 19/23) showed no significant difference. Non-RCT studies contributed to evidence favoring bEVT. Current RCTs provide an update of clinical evidence comparing bEVT and dEVT. However, they simultaneously contribute to an unnecessary overlap among studies. Contemporary observational studies demonstrated different but possibly confounded evidence. Thus, this issue still requires more clinical evidence under standard procedures.

Predicting Penumbra Salvage and Infarct Growth in Acute Ischemic Stroke: A Multifactor Survival Game

BACKGROUND

Effective treatment of acute ischemic stroke requires reperfusion of salvageable tissue. We investigated the predictors of penumbra salvage (PS) and infarct growth (IG) in a large cohort of stroke patients.

METHODS

In the ASTRAL registry from 2003 to 2016, we selected middle cerebral artery strokes <24 h with a high-quality CT angiography and CT perfusion. PS and IG were correlated in multivariate analyses with clinical, biochemical and radiological variables, and with clinical outcomes.

RESULTS

Among 4090 patients, 551 were included in the study, 50.8% male, mean age (±SD) 66.3 ± 14.7 years, mean admission NIHSS (±SD 13.3 ± 7.1) and median onset-to-imaging-time (IQR) 170 (102 to 385) minutes. Increased PS was associated with the following: higher BMI and lower WBC; neglect; larger penumbra; absence of early ischemic changes, leukoaraiosis and other territory involvement; and higher clot burden score. Reduced IG was associated with the following: non-smokers; lower glycemia; larger infarct core; absence of early ischemic changes, chronic vascular brain lesions, other territory involvement, extracranial arterial pathology and hyperdense middle cerebral artery sign; and higher clot burden score. When adding subacute variables, recanalization was associated with increased PS and reduced IG, and the absence of haemorrhage with reduced IG. Collateral status was not significantly associated with IG nor with PS. Increased PS and reduced IG correlated with better 3- and 12-month outcomes.

CONCLUSION

In our comprehensive analysis, multiple factors were found to be responsible for PS or IG, the strongest being radiological features. These findings may help to better select patients, particularly for more aggressive or late acute stroke treatment.

Recanalization Rate and Clinical Outcomes of Intravenous Tissue Plasminogen Activator Administration for Large Vessel Occlusion Stroke Patients

OBJECTIVE

Stroke caused from large vessel occlusion (LVO) has emerged as the most common stroke subtype worldwide. Intravenous tissue plasminogen activator administration (IV-tPA) and additional intraarterial thrombectomy (IA-Tx) is regarded as standard treatment. In this study, the authors try to find the early recanalization rate of IV-tPA in LVO stroke patients.

METHODS

Total 300 patients undertook IA-Tx with confirmed anterior circulation LVO, were analyzed retrospectively. Brain computed tomography angiography (CTA) was the initial imaging study and acute stroke magnetic resonance angiography (MRA) followed after finished IV-tPA. Early recanalization rate was evaluated by acute stroke MRA within 2 hours after the IV-tPA. In 167 patients undertook IV-tPA only and 133 non-recanalized patients by IV-tPA, additional IA-Tx tried (IV-tPA + IA-Tx group). And 131 patients, non-recanalized by IV-tPA (IV-tPA group) additional IA-Tx recommend and tried according to the patient condition and compliance.

RESULTS

Early recanalization rate of LVO after IV-tPA was 12.0% (36/300). In recanalized patients, favorable outcome (modified Rankin Scale, 0-2) was 69.4% (25/36) while it was 32.1% (42/131, p<0.001) in non-recanalized patients. Among 133 patients, nonrecanalized after intravenous recombinant tissue plasminogen activator and undertook additional IA-Tx, the clinical outcome was better than not undertaken additional IA-Tx (favorable outcome was 42.9% vs. 32.1%, p=0.046). Analysis according to the perfusion/diffusion (P/D)-mismatching or not, in patient with IV-tPA with IA-Tx (133 patients), favorable outcome was higher in P/ D-mismatching patient (52/104; 50.0%) than P/D-matching patients (5/29; 17.2%; p=0.001). Which treatment tired, P/D-mismatching was favored in clinical outcome (iv-tPA only, p=0.008 and IV-tPA with IA-Tx, p=0.001).

CONCLUSION

The P/D-mismatching influences on the recanalization and clinical outcomes of IV-tPA and IA-Tx. The authors would like to propose that we had better prepare IA-Tx when LVO is diagnosed on initial diagnostic imaging. Furthermore, if the patient shows P/D-mismatching on MRA after IV-tPA, additional IA-Tx improves treatment results and lessen the futile recanalization.

Direct Mechanical Thrombectomy Versus Prior Bridging Intravenous Thrombolysis in Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

The current guideline recommends using an intravenous tissue-type plasminogen activator (IV tPA) prior to mechanical thrombectomy (MT) in eligible acute ischemic stroke (AIS) with emergent large vessel occlusion (ELVO). Some recent studies found no significant differences in the long-term functional outcomes between bridging therapy (BT, i.e., IV tPA prior to MT) and direct MT (dMT).

METHODS

We conducted a systematic review and meta-analysis to compare the safety and functional outcomes between BT and dMT in AIS patients with ELVO who were eligible for IV tPA administration. Based on the ELVO location, patients were categorized as the anterior group (occlusion of the anterior circulation), or the combined group (occlusion of the anterior and/or posterior circulation). A subgroup analysis was performed based on the study type, i.e., RCT and non-RCT.

RESULTS

Thirteen studies (3985 patients) matched the eligibility criteria. Comparing the BT and dMT groups, no significant differences in terms of mortality and good functional outcome were observed at 90 days. Symptomatic intracranial hemorrhagic (sICH) events were more frequent in BT patients in the combined group (OR = 0.73, p = 0.02); this result remained significant only in the non-RCT subgroup (OR = 0.67, p = 0.03). The RCT subgroup had a significantly higher rate of successful revascularization in BT patients (OR = 0.73, p = 0.02).

CONCLUSIONS

Our meta-analysis uncovered no significant differences in functional outcome and mortality rate at 90 days between dMT and BT in patients with AIS who had ELVO. Although BT performed better in terms of successful recanalization rate, there is a risk of increased sICH rate in this group.

Utility of tPA Administration in Acute Treatment of Internal Carotid Artery Occlusions

Background

Intravenous tissue plasminogen activator (IV-tPA) remains part of the guidelines for acute ischemic stroke treatment, yet internal carotid artery occlusions (ICAO) are known to be poorly responsive to IV-tPA. It is unknown whether bridging thrombolysis (BT) is beneficial in such cases.

Purpose

We sought to evaluate whether the use of IV-tPA improved overall clinical outcomes in patients undergoing endovascular thrombectomy (EVT) for ICA occlusions.

Methods

Data from 1367 consecutive stroke cases treated with EVT from 2012-2019 were prospectively collected from a single center. Univariate and multivariate logistic regression were used to assess the relationship between IV-tPA administration and clinical outcome.

Results

153 patients were found to have carotid terminus and tandem ICAO who received EVT and presented within 4.5h of last seen well. 50% (n = 82) received IV tPA. There were no differences between the groups with respect to age, NIHSS, time to EVT and ASPECTS score. 53% had tandem ICA-MCA occlusions. Rate of recanalization (≥ TICI 2B) and sICH did not significantly differ between the two groups. Regression analysis demonstrated no effect of IV-tPA on modified Rankin Score (mRS) at 90 days and overall mortality. Factors significantly associated with reduced mortality included lower age, lower NIHSS, and better rate of recanalization.

Conclusions

There was no significant difference in clinical outcomes in those receiving BT vs. direct EVT for ICAO. For centers with optimal door-to-puncture times, bypassing IV-tPA may expedite recanalization times and potentially yield more favorable outcomes. Patients with higher NIHSS and tandem lesions may have better outcomes with BT.

Patient and procedure selection for mechanical thrombectomy: Toward personalized medicine and the role of artificial intelligence

Mechanical thrombectomy (MT) for ischemic stroke due to large vessel occlusion is standard of care. Evidence-based guidelines on eligibility for MT have been outlined and evidence to extend the treatment benefit to more patients, particularly those at the extreme ends of a stroke clinical severity spectrum, is currently awaited. As patient selection continues to be explored, there is growing focus on procedure selection including the tools and techniques of thrombectomy and associated outcomes. Artificial intelligence (AI) has been instrumental in the area of patient selection for MT with a role in diagnosis and delivery of acute stroke care. Machine learning algorithms have been developed to detect cerebral ischemia and early infarct core, presence of large vessel occlusion, and perfusion deficit in acute ischemic stroke. Several available deep learning AI applications provide ready visualization and interpretation of cervical and cerebral arteries. Further enhancement of AI techniques to potentially include automated vessel probe tools in suspected large vessel occlusions is proposed. Value of AI may be extended to assist in procedure selection including both the tools and technique of thrombectomy. Delivering personalized medicine is the wave of the future and tailoring the MT treatment to a stroke patient is in line with this trend.

Acute Ischemic Stroke caused by Internal Carotid Artery Occlusion: Impact of Occlusion Type on the Prognosis

METHODS

We retrospectively reviewed 67 AIS patients who had an ICA occlusion on computed tomography angiography (CTA) and underwent MT in a single tertiary center. ICA occlusion types were categorized as 1) true cervical ICA (cICA) occlusion (true occlusion), 2) pseudo-occlusion of the cICA (pseudo-occlusion), and 3) distal ICA (dICA) occlusion. We compared the clinical characteristics and their outcomes according to the ICA occlusion type.

RESULTS

Fourteen patients were diagnosed with true occlusion, 32 with pseudo-occlusion, and 21 with dICA occlusion. The main etiologies were atherothrombotic in true occlusion (64.3%) and cardioembolic in pseudo-occlusion (81.3%) and dICA occlusion (71.4%) (p<0.001). Pseudo-occlusion showed lower rates of successful reperfusion (37.5%, p=0.009, 78.6% in true occlusion and 71.4% in dICA occlusion and poor functional outcome at 3 months (18.8%, p=0.037, 50% in true occlusion and 47.6% in dICA occlusion) with statistical significance. The infarction volume (169.4±154.4 mL, p=0.004, 29.2±52.7mL in true occlusion and 105.8±13.4mL in dICA occlusion) was significantly higher in pseudo-occlusion. On multivariate logistic analysis, pseudo-occlusion (OR: 4.84, 95% CI: 1.02-22.87, p=0.023) was an independent risk factor for poor reperfusion, which was significantly associated with a poor functional prognosis (odds ratio [OR]: 22.04, 95% confidence interval [CI]: 1.99-243.83, p=0.012).

CONCULSIONS

Patients with pseudo-occlusion showed poorer clinical outcomes compared to other ICA occlusion types, possibly due to a poor reperfusion rate after MT.

Endovascular Treatment Effect Diminishes With Increasing Thrombus Perviousness: Pooled Data From 7 Trials on Acute Ischemic Stroke

Supplemental Digital Content is available in the text.

Background and Purpose:

Thrombus perviousness estimates residual flow along a thrombus in acute ischemic stroke, based on radiological images, and may influence the benefit of endovascular treatment for acute ischemic stroke. We aimed to investigate potential endovascular treatment (EVT) effect modification by thrombus perviousness.

Methods:

We included 443 patients with thin-slice imaging available, out of 1766 patients from the pooled HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke trials) data set of 7 randomized trials on EVT in the early window (most within 8 hours). Control arm patients (n=233) received intravenous alteplase if eligible (212/233; 91%). Intervention arm patients (n=210) received additional EVT (prior alteplase in 178/210; 85%). Perviousness was quantified by thrombus attenuation increase on admission computed tomography angiography compared with noncontrast computed tomography. Multivariable regression analyses were performed including multiplicative interaction terms between thrombus attenuation increase and treatment allocation. In case of significant interaction, subgroup analyses by treatment arm were performed. Our primary outcome was 90-day functional outcome (modified Rankin Scale score), resulting in an adjusted common odds ratio for a one-step shift towards improved outcome. Secondary outcomes were mortality, successful reperfusion (extended Thrombolysis in Cerebral Infarction score, 2B–3), and follow-up infarct volume (in mL).

Results:

Increased perviousness was associated with improved functional outcome. After adding a multiplicative term of thrombus attenuation increase and treatment allocation, model fit improved significantly (P=0.03), indicating interaction between perviousness and EVT benefit. Control arm patients showed significantly better outcomes with increased perviousness (adjusted common odds ratio, 1.2 [95% CI, 1.1–1.3]). In the EVT arm, no significant association was found (adjusted common odds ratio, 1.0 [95% CI, 0.9–1.1]), and perviousness was not significantly associated with successful reperfusion. Follow-up infarct volume (12% [95% CI, 7.0–17] per 5 Hounsfield units) and chance of mortality (adjusted odds ratio, 0.83 [95% CI, 0.70–0.97]) decreased with higher thrombus attenuation increase in the overall population, without significant treatment interaction.

Conclusions:

Our study suggests that the benefit of best medical care including alteplase, compared with additional EVT, increases in patients with more pervious thrombi.

Thrombolysis outcomes according to arterial characteristics of acute ischemic stroke by alteplase dose and blood pressure target

BACKGROUND

We explored the influence of low-dose intravenous alteplase and intensive blood pressure lowering on outcomes of acute ischemic stroke according to status/location of vascular obstruction in participants of the Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED).

METHODS

ENCHANTED was a multicenter, quasi-factorial, randomized trial to determine efficacy and safety of low- versus standard-dose intravenous alteplase and intensive- versus guideline-recommended blood pressure lowering in acute ischemic stroke patients. In those who had baseline computed tomography or magnetic resonance imaging angiography, the degree of vascular occlusion was grouped according to being no (NVO), medium (MVO), or large (LVO). Logistic regression models were used to determine 90-day outcomes (modified Rankin scale [mRS] shift [primary], other mRS cut-scores, intracranial hemorrhage, early neurologic deterioration, and recanalization) by vascular obstruction status/site. Heterogeneity in associations for outcomes across subgroups was estimated by adding an interaction term to the models.

RESULTS

There were 940 participants: 607 in alteplase arm only, 243 in blood pressure arm only, and 90 assigned to both arms. Compared to the NVO group, functional outcome was worse in LVO (mRS shift, adjusted OR [95% CI] 2.13 [1.56-2.90]) but comparable in MVO (1.34 [0.96-1.88]) groups. There were no differences in associations of alteplase dose or blood pressure lowering and outcomes across NVO/MVO/LVO groups (mRS shift: low versus standard alteplase dose 0.84 [0.54-1.30]/0.48 [0.25-0.91]/0.99 [0.75-2.09], P_interaction = 0.28; intensive versus standard blood pressure lowering 1.32 [0.74-2.38]/0.78 [0.31-1.94]/1.24 [0.64-2.41], P_interaction = 0.41), except for a borderline significant difference for intensive blood pressure lowering and increased early neurologic deterioration (0.63 [0.14-2.72]/0.17 [0.02-1.47]/2.69 [0.90-8.04], P_interaction = 0.05).

CONCLUSIONS

Functional outcome by dose of alteplase or intensity of blood pressure lowering is not modified by vascular obstruction status/site according to analyses from ENCHANTED, although these results are compromised by low statistical power.Clinical Trial Registration: http://www.clinicaltrials.gov. Unique identifiers: NCT01422616.

Efficacy and safety of normobaric hyperoxia combined with intravenous thrombolysis on acute ischemic stroke patients

Intravenous thrombolysis elevates the prognostic level of acute ischemic stroke (AIS) patients. Normobaric hyperoxia (NBO) delays the progression of the infarct core and promotes neurological recovery. However, it is uncertain whether NBO can further raise the prognostic level of AIS patients based on intravenous thrombolysis. To explore the efficacy and safety of NBO combined with intravenous thrombolysis on AIS patients. This observational study included anterior circulation stroke patients who received intravenous thrombolysis within 4.5 h after stroke onset. These patients were divided into two groups based on whether or not they received NBO therapy. The baseline data and the prognosis of the two groups were compared. The primary outcome was the proportion of functional independence (modified Rankin Scale 0-2) at 90 days post discharge. A total of 227 patients were included in this study. 125 patients received NBO therapy combined with intravenous thrombolysis, while 102 patients received intravenous thrombolysis only. Overall, the rate of recanalization was 83.3%. Consequently, 101 patients (80.8%) who received NBO combined with intravenous thrombolysis and 63 patients (61.8%) in the control group achieved functional independence (P = 0.002). Multivariable logistic regression analysis showed that NBO combined with intravenous thrombolysis over intravenous thrombolysis alone was associated with 90-day functional independence (OR: 2.318; 95% CI: 1.226-4.381; P = 0.01). This study verified the efficacy and safety of NBO combined with intravenous thrombolysis in AIS patients. Prospective study is needed to further substantiate these findings.

Risk Factors of Hypoperfusion on MRI of Ischemic Stroke Patients Within 7 Days of Onset

Objective: Hypoperfusion is an important factor determining the prognosis of ischemic stroke patients. The present study aimed to investigate possible predictors of hypoperfusion on MRI of ischemic stroke patients within 7 days of stroke onset.

Methods: Ischemic stroke patients, admitted to the comprehensive Stroke Center of Shanghai Fourth People's Hospital affiliated to Tongji University within 7 days of onset between January 2016 and June 2017, were recruited to the present study. Magnetic resonance imaging (MRI), including both diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI), was performed within 7 days of the symptom onset. Time to maximum of the residue function (T_max) maps were automatically evaluated using the RAPID software. The volume of hypoperfusion was measured outside the infarct area based on ADC < 620 × 10⁻⁶ mm²/s. The 90 d mRS score was assessed through either clinic visits or telephone calls. Multivariate step-wise analysis was used to assess the correlation between MR findings and clinical variables, including the demographic information, cardio-metabolic characteristics, and functional outcomes.

Results: Among 635 patients admitted due to acute ischemic stroke within 7 days of onset, 241 met the inclusion criteria. Hypoperfusion volume of 38 ml was the best cut-off value for predicting poor prognosis of patients with cerebral infarction (90 d-mRS score ≥ 2). The incidences of MR perfusion T_max > 4–6 s maps with a volume of 0–38 mL or >38 mL were 51.9% (125/241) and 48.1% (116/241), respectively. Prior stroke and vascular stenosis (≥70%) were associated with MR hypoperfusion. Multivariate step-wise analysis showed that prior stroke and vascular stenosis (≥70%) were risk factors of T_max > 4–6 s maps, and the odds ratios (OR) were 3.418 (adjusted OR 95% CI: 1.537–7.600), and 2.265 (adjusted OR, 95% CI: 1.199–4.278), respectively.

Conclusion: Our results suggest that prior stroke and vascular stenosis (≥70%) are strong predictors of hypoperfusion in patients with acute ischemic stroke within 7 days of stroke onset.

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

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

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

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

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

Management and prognosis of acute extracranial internal carotid artery occlusion

Acute occlusion of the internal carotid artery is the underlying etiology in 4 to 15% of all ischemic strokes. The clinical presentation varies considerably ranging from asymptomatic occlusion to severe ischemic strokes. Substantial differences in the acute management of acute symptomatic internal carotid artery occlusions (ICAO) exists between centers. Thusly, we comprised a narrative review of the natural course of acute ICAO and of available treatment options [i.v. thrombolysis, endovascular thrombectomy and stenting, bypass between the superficial temporal and the middle cerebral arteries (MCA) and carotid endarterectomy (CEA)]. We found that very few randomized treatment trials have been performed in patients acute symptomatic ICAO. Most evidence stems from case series and observational studies. Especially in older studies the intracranial vessel status has rarely been considered. After revision of these studies we concluded that the mainstay of the acute management of acute symptomatic ICAO is i.v. thrombolysis when applied within the label and in combination with mechanical thrombectomy in case of intracranial large vessel occlusion. In cases without intracranial large vessel occlusion mechanical thrombectomy of acute ICAO is associated with a risk of distal embolization. More research on prognostic parameters is needed to better characterize the risk of decompensation of collateral flow and to better define the time-window of intervention. When mechanical thrombectomy fails or is not available, surgical approaches are an alternative in selected patients.

Endovascular treatment and cognitive outcome after anterior circulation ischemic stroke

The impact of reperfusion therapies on cognition has been poorly explored and little knowledge exists. We explored the influence of endovascular treatment (EVT) on cognitive outcome in patients with anterior circulation ischemic stroke. Patients presenting with ischemic stroke due to anterior large vessel occlusion who underwent intravenous thrombolysis (IVT) alone or EVT plus IVT were recruited. Cognitive abilities were evaluated at 6 months from stroke through a neuropsychological test battery. A total of 88 patients with a mean age of 66.3 ± 12.9 years were included, of which 38 treated with IVT alone and 50 with IVT plus EVT. Compared to patients treated with IVT alone, patients who received EVT plus IVT performed significantly better at the neuropsychological tests exploring executive functions, attention, abstract reasoning, visuospatial ability, visual and verbal and memory. At multivariable regression analysis, the EVT was independently associated with the 6-month cognitive performance after the adjustment for age, sex, admission National Institutes of Health Stroke Scale score, systolic blood pressure, glucose level, Alberta Stroke Program Early CT score, side of stroke, site of occlusion, and Back Depression Inventory score [Stroop Test Word Reading: _adjβ = 13.99, 95% confidence interval (CI) 8.47–19.50, p < 0.001; Stroop Test Colour Naming: _adjβ = 6.63, 95% CI 2.46–10.81, p = 0.002; Trail Making Test-A: _adjβ = − 92.98, 95% CI − 153.76 to − 32.20, p = 0.003; Trail Making Test-B: _adjβ = − 181.12, 95% CI − 266.09 to − 96.15; p < 0.001; Digit Span Test Forward: _adjβ = 1.44, 95% CI 0.77–2.10, p < 0.001; Digit Span Test Backward: _adjβ = 1.10, 95% CI 0.42–1.77, p = 0.002; Coloured Progressive Matrices: _adjβ = 5.82, 95% CI 2.71–8.93, p < 0.001; Rey Complex Figure Test-Copy: _adjβ = 6.02, 95% CI 2.74–9.30, p < 0.001; Rey Complex Figure Test-Immediate recall: _adjβ = 6.00, 95% CI 2.34–9.66, p = 0.002; Rey Complex Figure Test-Delayed recall: _adjβ = 5.73, 95% CI 1.95–9.51, p = 0.003; Rey Auditory Verbal Learning Test-Immediate recall: _adjβ = 12.60, 95% CI 6.69–18.52, p < 0.001; Rey Auditory Verbal Learning Test-Delayed recall: _adjβ = 1.85, 95% CI 0.24–3.45, p = 0.025]. Patients treated with EVT plus IVT had better cognitive performance than patients treated with IVT alone at 6 months from anterior circulation ischemic stroke.

Outcome and effect of endovascular treatment in stroke associated with acute extracranial internal carotid artery occlusion: Single-center experience in Japan

BACKGROUND

Positive data from several randomized controlled trials (RCTs) of endovascular treatment (EVT) for acute ischemic stroke (AIS) patients with anterior circulation large vessel occlusion (ACLVO) have emerged. However, little evidence exists on EVT for acute extracranial internal carotid artery (EC-ICA) occlusion. We therefore analysed the outcome and effect of EVT on AIS due to ACLVO caused by EC-ICA occlusion, including tandem occlusion compared with that caused by pure intracranial artery occlusion.

METHODS

A total of 135 consecutive AIS patients with ACLVO between July 2014 and December 2017 were identified. We retrospectively analysed the efficacy of EVT for ACLVO after introducing a stent retriever (SR). We classified ACLVO into the following categories: group A, intracranial artery occlusion without EC-ICA occlusion (pure intracranial artery occlusion), and group B, ipsilateral EC-ICA occlusion with/without intracranial artery occlusion.

RESULTS

In total, 65 patients were enrolled. Group A comprised 71% (46/65) of all cases. No difference was observed in terms of age, National Institute of Health Stroke Scale (NIHSS) score, Alberta Stroke Program Early Computed Tomography Score-Diffusion Weighted imaging (ASPECTS-DWI), several clinical time intervals, rate of successful revascularization (74% versus 84%), and rate of functional independence (42% versus 39%) between groups A and B. In all patients, an ASPECTS-DWI ≥6 and an onset-to-door time ≤6 h were associated with good outcome, whereas intracranial artery occlusion without EC-ICA occlusion (pure intracranial artery occlusion) was not.

CONCLUSIONS

The outcomes support the efficacy of EVT in stroke associated with acute EC-ICA occlusion. In the EVT of AIS due to ACLVO, there was no significant difference in the results between ipsilateral EC-ICA occlusion with/without intracranial artery occlusion and intracranial artery occlusion without EC-ICA occlusion (pure intracranial artery occlusion).

Blood Pressure Management Following Acute Ischemic Stroke: A Review of Primary Literature

Elevated blood pressure is common in patients with acute ischemic stroke. While this may occur secondary to the body's own response to preserve cerebral blood flow, elevated blood pressure may also increase the risk of hemorrhagic transformation. Current guidelines recommend various blood pressure goals based upon multiple factors, including thresholds specific to certain treatment interventions. Despite these guidelines, there is limited evidence to support specific blood pressure targets, and variability in clinical practice is common. The purpose of this review was to discuss blood pressure management in adult patients with acute ischemic stroke, focusing on appropriate targets in the setting of alteplase administration, mechanical thrombectomy, and hemorrhagic transformation.

Prevalence of a Multiple Territory Stroke Pattern After Intravenous Thrombolysis

BACKGROUND

It has been proposed that the presence of a multiple territory stroke pattern (MTSP) on brain imaging may aid identification of patients with covert atrial fibrillation (AF). However, it is uncertain whether this association holds true among patients treated with intravenous recombinant tissue plasminogen activator (rtPA) because clot fragmentation may affect MTSP prevalence.

METHODS/DESIGN

Retrospective analysis of 149 acute ischemic stroke patients treated with intravenous rtPA who underwent brain MRI. Presence of multiple acute infarctions on brain MRI that involved more than one vascular territory was considered to denote MTSP. Stroke etiology was categorized as nonembolic, cardioembolic (CES), and embolic stroke of undetermined source (ESUS).

RESULTS

In the entire cohort, subjects with CES and ESUS had significantly more often an MTSP than subjects with other determined stroke mechanism (P= .007). Although numerically relatively more patients had an MTSP as compared to a non-MTSP among subjects with CES (52% versus 33.9%) and ESUS (44% versus 34.7%), this difference did not reach significance after Bonferroni-adjustment for multiple comparisons (P> .05, each). There was no difference in the prevalence of an MTSP among subjects with known (n = 11/51; 21.6%) versus subsequently diagnosed (n = 1/3; 33.3%) AF (P= .54).

CONCLUSIONS

Our findings indicate that the known association of multiterritory infarct with AF and ESUS is maintained after thrombolysis. In light of its high specificity, MTSP represents a good marker for AF-related stroke etiology; nevertheless, overall sensitivity for AF was low highlighting that an absent MTSP does not rule out AF.

Acute ischaemic stroke interventions: large vessel occlusion and beyond

Care for acute ischaemic stroke is one of the most rapidly evolving fields due to the robust outcomes achieved by mechanical thrombectomy. Large vessel occlusion (LVO) accounts for up to 38% of acute ischaemic stroke and comes with devastating outcomes for patients, families and society in the pre-intervention era. A paradigm shift and a breakthrough brought mechanical thrombectomy back into the spotlight for acute ischaemic stroke; this was because five randomised controlled trials from several countries concluded that mechanical thrombectomy for acute stroke offered overwhelming benefits. This review article will present a comprehensive overview of LVO management, techniques and devices used, and the future of stroke therapy. In addition, we review our institution experience of mechanical thrombectomy for posterior and distal circulation occlusion.

Outcomes of Endovascular Thrombectomy Performed 6-24 h after Acute Stroke from Extracranial Internal Carotid Artery Occlusion

Thrombectomy has demonstrated clinical efficacy against acute ischemic stroke caused by intracranial occlusion of the internal carotid artery (ICA), even if performed 6–24 h after onset. This study investigated the outcomes of thrombectomy performed 6–24 h after stroke onset caused by extracranial ICA occlusion. Of 586 stroke patients receiving thrombectomy during the past 3 years and registered in the Tama Registry of Acute Endovascular Thrombectomy database, 24 were identified with ICA occlusion (14 extracranial and 10 intracranial), known to be well 6–24 h before presentation, and with pre-stroke modified Rankin Scale (mRS) score of 0 or 1. Clinical outcomes measured were the rate of functional independence at 90 days according to mRS score of 0–2 and 90 day mortality rate. Of patients with extracranial ICA occlusion, two received additional carotid stenting with thrombectomy. The median interval between the last time the patient was known to be well and hospital arrival was 601 (interquartile range, 476–729 min). Both the rate of functional independence at 90 days and 90 day mortality were comparable between patients with extracranial or intracranial ICA occlusion (36% vs. 40% and 7% vs. 10%, respectively). No symptomatic intracranial hemorrhages occurred within 24 h following treatment of extracranial ICA occlusion. Thrombectomy performed 6–24 h after extracranial ICA results in acceptable functional outcome. Further clinical study is warranted to better define the temporal window of thrombectomy for acceptable functional outcome in patients with extracranial ICA occlusion.

Fingolimod enhances the efficacy of delayed alteplase administration in acute ischemic stroke by promoting anterograde reperfusion and retrograde collateral flow

OBJECTIVE

The present study was undertaken to determine the efficacy of coadministration of fingolimod with alteplase in acute ischemic stroke patients in a delayed time window.

METHODS

This was a prospective, randomized, open-label, blinded endpoint clinical trial, enrolling patients with internal carotid artery or middle cerebral artery proximal occlusion within 4.5 to 6 hours from symptom onset. Patients were randomly assigned to receive alteplase alone or alteplase with fingolimod. All patients underwent pretreatment and 24-hour noncontrast computed tomography (CT)/perfusion CT/CT angiography. The coprimary endpoints were the decrease of National Institutes of Health Stroke Scale scores over 24 hours and the favorable shift of modified Rankin Scale score (mRS) distribution at day 90. Exploratory outcomes included vessel recanalization, anterograde reperfusion, and retrograde reperfusion of collateral flow.

RESULTS

Each treatment group included 23 patients. Compared with alteplase alone, patients receiving fingolimod plus alteplase exhibited better early clinical improvement at 24 hours and a favorable shift of mRS distribution at day 90. In addition, patients who received fingolimod and alteplase exhibited a greater reduction in the perfusion lesion accompanied by suppressed infarct growth by 24 hours. Fingolimod in conjunction with alteplase significantly improved anterograde reperfusion of downstream territory and prevented the failure of retrograde reperfusion from collateral circulation.

INTERPRETATION

Fingolimod may enhance the efficacy of alteplase administration in the 4.5- to 6-hour time window in patients with a proximal cerebral arterial occlusion and salvageable penumbral tissue by promoting both anterograde reperfusion and retrograde collateral flow. These findings are instructive for the design of future trials of recanalization therapies in extended time windows. Ann Neurol 2018;84:725-736.

Endovascular Reperfusion for Acute Isolated Cervical Carotid Occlusions: The Concept of "Hemodynamic Thrombectomy"

Background/Aims

Endovascular treatment improves the outcomes of patients presenting with acute large vessel occlusions. Isolated proximal carotid occlusions presenting with hemodynamic ischemic stroke may probably also benefit from endovascular treatment. We aimed to assess the clinical and radiological data findings on patients who underwent endovascular treatment for acute ischemic stroke related to an isolated cervical carotid artery occlusion.

Methods

Of a consecutive series of 223 patients who were admitted with acute ische-mic stroke and were treated by thrombectomy, we included 9 patients with isolated cervical internal carotid occlusions.

Results

The mean baseline National Institutes of Health Stroke Scale (NIHSS) score was 11.8. Complete carotid recanalization was achieved in 5 of the 9 patients (55.5%). In 2 patients, vertebral angioplasty was performed to improve the collateral flow. All patients had a modified Thrombolysis in Cerebral Infarction (mTICI) score of 3 at the end of the procedures. A good neurological outcome, defined as a modified Rankin Scale score ≤2 at the 3-month follow-up, was observed in 6 patients (66.7%). No symptomatic intracranial hemorrhages or deaths occurred during the 3 months of follow-up.

Conclusions

The endovascular recanalization of isolated cervical carotid occlusions presenting with acute ischemic stroke symptoms is feasible. Because isolated cervical carotid occlusions are associated with hemodynamic ischemic symptoms, if carotid recanalization cannot be achieved, stenting other cervical arteries' stenoses, with a focus on intracranial flow improvement, appears to be a reasonable strategy. Large controlled studies are necessary to assess the safety and efficacy of recanalization of acute isolated cervical carotid occlusions.

Mechanical thrombectomy in acute ischaemic stroke: a review of the different techniques

Endovascular mechanical thrombectomy (MT) is reserved for acute ischaemic stroke secondary to large vessel occlusion. The various MT techniques employed in the treatment of hyperacute strokes are constantly evolving with new devices and improvisation of existing technology (Wahlgren, et al 2016). In this review, we describe a variety of MT techniques gained from our experience of performing over 350 procedures in 7 years of providing a 24/7 service within the national framework of a hyperacute stroke centre. We outline a number of endovascular techniques, procedure limitations, and potential complications.

Current evidence for endovascular therapy in stroke and remaining uncertainties

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

NADPH Oxidase-Related Pathophysiology in Experimental Models of Stroke

Several experimental studies have indicated that nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (Nox) exert detrimental effects on ischemic brain tissue; Nox-knockout mice generally exhibit resistance to damage due to experimental stroke following middle cerebral artery occlusion (MCAO). Furthermore, our previous MCAO study indicated that infarct size and blood-brain barrier breakdown are enhanced in mice with pericyte-specific overexpression of Nox4, relative to levels observed in controls. However, it remains unclear whether Nox affects the stroke outcome directly by increasing oxidative stress at the site of ischemia, or indirectly by modifying physiological variables such as blood pressure or cerebral blood flow (CBF). Because of technical problems in the measurement of physiological variables and CBF, it is often difficult to address this issue in mouse models due to their small body size; in our previous study, we examined the effects of Nox activity on focal ischemic injury in a novel congenic rat strain: stroke-prone spontaneously hypertensive rats with loss-of-function in Nox. In this review, we summarize the current literature regarding the role of Nox in focal ischemic injury and discuss critical issues that should be considered when investigating Nox-related pathophysiology in animal models of stroke.

Special Endovascular Treatment for Acute Large Artery Occlusion Resulting From Atherosclerotic Disease

BACKGROUND

Acute intracranial atherosclerotic disease (IAD)-related large artery occlusion (LAO) is typically refractory to mechanical thrombectomy. We evaluated the feasibility and safety of emergency balloon-assisted or stent-assisted angioplasty performed with tirofiban administration for acute IAD-related LAO.

METHODS

We identified, from among 55 consecutive patients who underwent endovascular treatment for LAO, 12 patients with acute IAD-related LAO who underwent balloon-assisted or stent-assisted angioplasty with (n = 3) or without passage of a stent retriever. The treatment included tirofiban administration. We obtained, from patients' clinical records, thrombolysis in cerebral infarction scores (to assess the extent of reperfusion), follow-up magnetic resonance angiography images (to assess patency of the responsive arteries), and 90-day modified Rankin (mRS) scores (to assess outcomes).

RESULTS

Temporary blood flow and severe stenosis were observed angiographically in all 12 patients, either when the stent retriever was deployed or when a microcatheter was advanced through the site of occlusion. Persistent recanalization was achieved in all patients, and there was no operative complication or arterial reocclusion. All 8 patients with an occluded major artery in the anterior circulation had a good outcome, with an mRS score of ≤2. Two of the 4 patients with basilar artery occlusion had a good outcome, with an mRS score of ≤2. One patient (25%) died within 72 hours after procedure.

CONCLUSIONS

Our data point to the safety and feasibility of emergency balloon-assisted or stent-assisted angioplasty performed with tirofiban administration and a single or no passage of the stent retriever for acute IAD-related LAO.

Revascularization of tandem occlusions in acute ischemic stroke: review of the literature and illustrative case

OBJECTIVE

Tandem occlusions continue to represent a major challenge in patients with acute ischemic stroke (AIS). The anterograde approach with proximal to distal revascularization as well as the retrograde approach with distal to proximal revascularization have been reported without clear consensus or standard guidelines.

METHODS

The authors performed a comprehensive search of the PubMed database for studies including patients with carotid occlusions and tandem distal occlusions treated with endovascular therapy. They reviewed the type of approach employed for endovascular intervention and clinical outcomes reported with emphasis on the revascularization technique. They also present an illustrative case of AIS and concurrent proximal cervical carotid occlusion and distal middle cerebral artery occlusion from their own experience in order to outline the management dilemma for similar cases.

RESULTS

A total of 22 studies were identified, with a total of 790 patients with tandem occlusions in AIS. Eleven studies used the anterograde approach, 3 studies used the retrograde approach, 4 studies used both, and in 4 studies the approach was not specified. In the studies that reported Thrombolysis in Cerebral Infarction (TICI) grades, an average of 79% of patients with tandem occlusions were reported to have an outcome of TICI 2b or better. One study found good clinical outcome in 52.5% of the thrombectomy-first group versus 33.3% in the stent-first group, as measured by the modified Rankin Scale (mRS). No study evaluated the difference in time to reperfusion for the anterograde and retrograde approach and its association with clinical outcome. The patient in the illustrative case had AIS and tandem occlusion of the internal carotid and middle cerebral arteries and underwent distal revascularization using a Solitaire stent retrieval device followed by angioplasty and stent treatment of the proximal cervical carotid occlusion. The revascularization was graded as TICI 2b; the postintervention National Institutes of Health Stroke Scale (NIHSS) score was 17, and the discharge NIHSS score was 7. The admitting, postoperative, and 30-day mRS scores were 5, 1, and 1, respectively.

CONCLUSIONS

In stroke patients with tandem occlusions, distal to proximal revascularization represents a reasonable treatment approach and may offer the advantage of decreased time to reperfusion, which is associated with better functional outcome. Further studies are warranted to determine the best techniques in endovascular therapy to use in this subset of patients in order to improve clinical outcome.

Treatment of stroke with early imaging and revascularization: when to be aggressive?

Neuroimaging has a key role in the assessment and treatment of acute stroke. Cerebral computer tomography is the first step to differentiate hemorragic from ischemic stroke and to detect, in the latter, early signs representative of the lesion severity and predicting a possible hemorrhagic infarction after thrombolytic treatment.Advanced neuroimaging techniques are relevant in the assessment of the ischemic and/or hypo-perfused area, being an essential tool in uncertain situations or when the time of symptoms onset is unavailable, increasing the efficacy and safety of endovenous thrombolysis by enlarging its therapeutic window and leading to more accurate selection of patients to be treated.Moreover, advanced neuroimaging may be of help in choosing the patients to be submitted to endovascular treatment when occlusion of an intracranial artery is documented, either after intravenous thrombolysis or as a primary approach.Here we describe the impact of neuroimaging in the decisional process in acute ischemic stroke, presenting the literature evidence on the topic, especially regarding the recent trials on endovascular treatment.

Symbiotic relationship of IV-tPA and mechanical thrombectomy in a case of acute tandem ICA-MCA occlusion

INTRO

In light of the recent successful mechanical thrombectomy trials, the need for IV-tPA prior is under investigation. Few cases demonstrate angiographically the role of both mechanical and chemical strategies at achieving reperfusion.

CASE REPORT

A 63year-old male presented with an NIHSS 20. CTA demonstrated an acute occlusion of the left cervical and intracranial ICA and MCA. IV-tPA was administered, followed by immediate reperfusion of the cervical ICA with carotid stenting and mechanical thrombectomy. Within the next 10min, the entire intracranial clot burden dissolved under angiographic control. TICI 3 reperfusion was achieved without any further intervention. Post-procedure, the patient recovered fully to an NIHSS of 0.

CONCLUSION

This case underscores the importance of IV-tPA administration in conjunction to mechanical thrombectomy. The interventionalist should take advantage of the symbiotic effect of the IV-tPA administration, which remains the standard of care so far.

Arterial Obstruction on Computed Tomographic or Magnetic Resonance Angiography and Response to Intravenous Thrombolytics in Ischemic Stroke

BACKGROUND AND PURPOSE

Computed tomographic angiography and magnetic resonance angiography are used increasingly to assess arterial patency in patients with ischemic stroke. We determined which baseline angiography features predict response to intravenous thrombolytics in ischemic stroke using randomized controlled trial data.

METHODS

We analyzed angiograms from the IST-3 (Third International Stroke Trial), an international, multicenter, prospective, randomized controlled trial of intravenous alteplase. Readers, masked to clinical, treatment, and outcome data, assessed prerandomization computed tomographic angiography and magnetic resonance angiography for presence, extent, location, and completeness of obstruction and collaterals. We compared angiography findings to 6-month functional outcome (Oxford Handicap Scale) and tested for interactions with alteplase, using ordinal regression in adjusted analyses. We also meta-analyzed all available angiography data from other randomized controlled trials of intravenous thrombolytics.

RESULTS

In IST-3, 300 patients had prerandomization angiography (computed tomographic angiography=271 and magnetic resonance angiography=29). On multivariable analysis, more extensive angiographic obstruction and poor collaterals independently predicted poor outcome (P<0.01). We identified no significant interaction between angiography findings and alteplase effect on Oxford Handicap Scale (P≥0.075) in IST-3. In meta-analysis (5 trials of alteplase or desmoteplase, including IST-3, n=591), there was a significantly increased benefit of thrombolytics on outcome (odds ratio>1 indicates benefit) in patients with (odds ratio, 2.07; 95% confidence interval, 1.18-3.64; P=0.011) versus without (odds ratio, 0.88; 95% confidence interval, 0.58-1.35; P=0.566) arterial obstruction (P for interaction 0.017).

CONCLUSIONS

Intravenous thrombolytics provide benefit to stroke patients with computed tomographic angiography or magnetic resonance angiography evidence of arterial obstruction, but the sample was underpowered to demonstrate significant treatment benefit or harm among patients with apparently patent arteries.

CLINICAL TRIAL REGISTRATION

URL: http://www.isrctn.com. Unique identifier: ISRCTN25765518.

Treatment Strategies for Acute Ischemic Stroke Caused by Carotid Artery Occlusion

Background: Acute ischemic stroke caused by internal carotid artery (ICA) occlusion usually has a poor prognosis, especially the T occlusion cases without functional collaterals. The efficacy of intravenous (IV) or intra-arterial (IA) thrombolysis with recombinant tissue plasminogen activator (rt-PA) remains ambiguous in these patients. Eendovascular recanalization of the occluded carotid has been attempted in recent years as a potential strategy. However, the different etiologies of ICA occlusion pose a significant challenge to neurointerventionists. Recently, several endovascular evolvements have been reported in treating carotid occlusion-related stroke. This review summarizes the current status of treatment for acute ICA occlusion.

Intravenous Thrombolysis for Acute Ischemic Stroke due to Cervical Internal Carotid Artery Occlusion

BACKGROUND

Internal carotid artery (ICA) occlusions are poorly responsive to intravenous thrombolysis with tissue plasminogen activator (IV-tPA) in acute ischemic stroke (AIS). Most study populations have combined intracranial and extracranial ICA occlusions for analysis; few have studied purely cervical ICA occlusions. We evaluated AIS patients with acute cervical ICA occlusion treated with IV-tPA to identify predictors of outcomes.

METHODS

We studied 550 consecutive patients with AIS who received IV-tPA and identified 100 with pure acute cervical ICA occlusion. We evaluated the associations of vascular risk factors, National Institutes of Health Stroke Scale (NIHSS) score, and leptomeningeal collateral vessel status via 3 different grading systems, with functional recovery at 90 days, mortality, recanalization of the primary occlusion, and symptomatic intracranial hemorrhage (SICH). Modified Rankin Scale score 0-1 was defined as an excellent outcome.

RESULTS

The 100 patients had mean age of 67.8 (range 32-96) and median NIHSS score of 19 (range 4-33). Excellent outcomes were observed in 27% of the patients, SICH in 8%, and mortality in 21%. Up to 54% of the patients achieved recanalization at 24 hours. On ordinal regression, good collaterals showed a significant shift in favorable outcomes by Maas, Tan, or ASPECTS collateral grading systems. On multivariate analysis, good collaterals also showed reduced mortality (OR .721, 95% CI .588-.888, P = .002) and a trend to less SICH (OR .81, 95% CI .65-1.007, P = .058). Interestingly, faster treatment was also associated with favorable functional recovery (OR 1.028 per minute, 95% CI 1.010-1.047, P = .001).

CONCLUSIONS

Improved outcomes are seen in patients with early acute cervical ICA occlusion and better collateral circulation. This could be a valuable biomarker for decision making.

Mechanical thrombectomy with the ERIC retrieval device: initial experience

Objective

To report our experience with the Embolus Retriever with Interlinked Cage (ERIC) stentriever for use in mechanical endovascular thrombectomy (MET).

Methods

Thirty-four consecutive patients with acute stroke (21 men and 13 women; median age 66 years) determined appropriate for MET were treated with ERIC and prospectively included over a 6-month period at three different centers. The ERIC device differs from typical stentrievers in that it is designed with a series of interlinked adjustable nitinol cages that allow for fast thrombus capture, integration, and withdrawal. The evaluated endpoints were successful revascularization (Thrombolysis in Cerebral Infarction (TICI) 2b–3) and good clinical outcomes at 3 months (modified Rankin Scale (mRS) 0–2).

Results

Locations of the occlusions included the middle cerebral artery (13 patients), terminal carotid artery (11 patients), basilar artery (1 patient), and tandem occlusions (9 patients). IV thrombolysis was performed in 20/34 (58.8%) patients. Median times from symptom onset to recanalization and from puncture to recanalization were 325.5 min (180–557) and 78.5 min (14–183), respectively. Used as the first-line device, ERIC achieved a successful recanalization in 20/24 (83.3%) patients. Successful recanalization was associated with lower National Institutes of Health Stroke Scale scores at 24 h (8±6.5 vs 21.5±2.1; p=0.008) and lower mRS at 3 months (2.7±2.1 vs 5.3±1.1; p=0.04). Three procedural complications and four asymptomatic hemorrhages were recorded. Good clinical outcomes at 3 months were seen in 15/31 (48.4%) patients.

Conclusions

The ERIC device is an innovative stentriever allowing fast, effective, and safe MET.

Solitaire™ with the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke (SWIFT PRIME) trial: protocol for a randomized, controlled, multicenter study comparing the Solitaire revascularization device with IV tPA with IV tPA alone in acute ischemic stroke

Rationale

Early reperfusion in patients experiencing acute ischemic stroke is critical, especially for patients with large vessel occlusion who have poor prognosis without revascularization. Solitaire™ stent retriever devices have been shown to immediately restore vascular perfusion safely, rapidly, and effectively in acute ischemic stroke patients with large vessel occlusions.

Aim

The aim of the study was to demonstrate that, among patients with large vessel, anterior circulation occlusion who have received intravenous tissue plasminogen activator, treatment with Solitaire revascularization devices reduces degree of disability 3 months post stroke.

Design

The study is a global multicenter, two-arm, prospective, randomized, open, blinded end-point trial comparing functional outcomes in acute ischemic stroke patients who are treated with either intravenous tissue plasminogen activator alone or intravenous tissue plasminogen activator in combination with the Solitaire device. Up to 833 patients will be enrolled.

Procedures

Patients who have received intravenous tissue plasminogen activator are randomized to either continue with intravenous tissue plasminogen activator alone or additionally proceed to neurothrombectomy using the Solitaire device within six-hours of symptom onset.

Study Outcomes

The primary end-point is 90-day global disability, assessed with the modified Rankin Scale (mRS). Secondary outcomes include mortality at 90 days, functional independence (mRS ≤ 2) at 90 days, change in National Institutes of Health Stroke Scale at 27 h, reperfusion at 27 h, and thrombolysis in cerebral infarction 2b/3 flow at the end of the procedure.

Analysis

Statistical analysis will be conducted using simultaneous success criteria on the overall distribution of modified Rankin Scale (Rankin shift) and proportions of subjects achieving functional independence (mRS 0–2).

A Mobile Stroke Treatment Unit for Field Triage of Patients for Intraarterial Revascularization Therapy

INTRODUCTION

Favorable outcomes in intraarterial therapy (IAT) for acute ischemic stroke (AIS) are related to early vessel recanalization. The mobile stroke treatment unit (MSTU) is an on-site, prehospital, treatment team, laboratory, and CT scanner that reduces time to treatment for intravenous thrombolysis and may also shorten time to IAT.

METHODS

Using our MSTU database, we identified patients that underwent IAT for AIS. We compared the key time metrics to historical controls, which included patients that underwent IAT at our institution six months prior to implementation of the MSTU. We further divided the controls into two groups: (1) transferred to our institution for IAT and (2) directly presented to our emergency room and underwent IAT.

RESULTS

After 164 days of service, the MSTU transported 155 patients of which 5 underwent IAT. We identified 5 historical controls that were transferred to our center for IAT. Substantial reduction in times including median door to initial CT (12 minute vs. 32 minute), CT to IAT (82 minute vs. 165 minute), and door to MSTU/primary stroke center departure (37 minute vs. 106 minute) were noted among the two groups. Compared to the 6 patients who presented to our institution directly, the MSTU process times were also shorter.

CONCLUSION

Our initial experience shows that MSTU may help in early triage and shorten the time to IAT for AIS.

Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke

BACKGROUND

Among patients with acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, less than 40% regain functional independence when treated with intravenous tissue plasminogen activator (t-PA) alone. Thrombectomy with the use of a stent retriever, in addition to intravenous t-PA, increases reperfusion rates and may improve long-term functional outcome.

METHODS

We randomly assigned eligible patients with stroke who were receiving or had received intravenous t-PA to continue with t-PA alone (control group) or to undergo endovascular thrombectomy with the use of a stent retriever within 6 hours after symptom onset (intervention group). Patients had confirmed occlusions in the proximal anterior intracranial circulation and an absence of large ischemic-core lesions. The primary outcome was the severity of global disability at 90 days, as assessed by means of the modified Rankin scale (with scores ranging from 0 [no symptoms] to 6 [death]).

RESULTS

The study was stopped early because of efficacy. At 39 centers, 196 patients underwent randomization (98 patients in each group). In the intervention group, the median time from qualifying imaging to groin puncture was 57 minutes, and the rate of substantial reperfusion at the end of the procedure was 88%. Thrombectomy with the stent retriever plus intravenous t-PA reduced disability at 90 days over the entire range of scores on the modified Rankin scale (P<0.001). The rate of functional independence (modified Rankin scale score, 0 to 2) was higher in the intervention group than in the control group (60% vs. 35%, P<0.001). There were no significant between-group differences in 90-day mortality (9% vs. 12%, P=0.50) or symptomatic intracranial hemorrhage (0% vs. 3%, P=0.12).

CONCLUSIONS

In patients receiving intravenous t-PA for acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, thrombectomy with a stent retriever within 6 hours after onset improved functional outcomes at 90 days. (Funded by Covidien; SWIFT PRIME ClinicalTrials.gov number, NCT01657461.).

Stroke Mimics and Acute Stroke Evaluation: Clinical Differentiation and Complications after Intravenous Tissue Plasminogen Activator

BACKGROUND

Intravenous tissue-plasminogen activator remains the only U.S. Food and Drug Administration-approved treatment for acute ischemic stroke. Timely administration of fibrinolysis is balanced with the need for accurate diagnosis. Stroke mimics represent a heterogeneous group of patients presenting with acute-onset focal neurological deficits. If these patients arrive within the extended time window for acute stroke treatment, these stroke mimics may erroneously receive fibrinolytics.

OBJECTIVE

This review explores the literature and presents strategies for differentiating stroke mimics.

DISCUSSION

Clinical outcome in stroke mimics receiving fibrinolytics is overwhelmingly better than their stroke counterparts. However, the risk of symptomatic intracranial hemorrhage remains a real but rare possibility. Certain presenting complaints and epidemiological risk factors may help differentiate strokes from stroke mimics; however, detection of stroke often depends on presence of posterior vs. anterior circulation strokes. Availability of imaging modalities also assists in diagnosing stroke mimics, with magnetic resonance imaging offering the most sensitivity and specificity.

CONCLUSION

Stroke mimics remain a heterogeneous entity that is difficult to identify. All studies in the literature report that stroke mimics treated with intravenous fibrinolysis have better clinical outcome than their stroke counterparts. Although symptomatic intracranial hemorrhage remains a real threat, literature searches have identified only two cases of symptomatic intracranial hemorrhage in stroke mimics treated with fibrinolytics.

Comparing perfusion CT evaluation algorithms for predicting outcome after endovascular treatment in anterior circulation ischaemic stroke

AIM

To analyse perfusion CT (PCT) evaluation algorithms for their predictive value for outcome after endovascular therapy (ET) in acute ischaemic stroke.

MATERIALS AND METHODS

Twenty-six patients were prospectively enrolled to undergo endovascular therapy for moderate to severe [National Institute of Health Stroke Scale (NIHSS) score of ≥5] anterior circulation stroke ≤6 h of onset. PCT datasets were evaluated according to three algorithms: visual mismatch estimate (VME), Alberta Stroke Programme Early CT Score (ASPECTS) perfusion, and quantitative perfusion ratios (QPRs: RCBF, RCBV) of cerebral blood flow (CBF) and volume (CBV). Results were correlated with outcome measures [NIHSS score at discharge, NIHSS score change until discharge (ΔNIHSSA/D), mRS at 90 days (mRS90d)] and compared with a matched control group.

RESULTS

Recanalization was achieved in 73%, median NIHSS score decreased from 14 to 5 at discharge. The treatment and control group did not differ by VME and ASPECTS perfusion, nor did VME correlate with any of the three outcome measures. ASPECTS perfusion was not predictive of any outcome measure in the ET group. RCBF and RCBV were associated with ΔNIHSSA/D in controls and, inversely, the ET group, but not with mRS90d. Receiver operating characteristic (ROC) analysis of RCBF (and RCBV) showed a positive predictive and negative predictive value of 87% (78%) and 74% (73%), respectively, for discriminating major neurological improvement (ΔNIHSSA/D <7 versus ≥7).

CONCLUSIONS

Implementation of QPRs for CBF and CBV are superior to clinically used VME and ASPECTS perfusion evaluation methods for predicting early outcome after ET for anterior circulation stroke.

Endovascular treatment for Small Core and Anterior circulation Proximal occlusion with Emphasis on minimizing CT to recanalization times (ESCAPE) trial: methodology

ESCAPE is a prospective, multicenter, randomized clinical trial that will enroll subjects with the following main inclusion criteria: less than 12 h from symptom onset, age > 18, baseline NIHSS >5, ASPECTS score of >5 and CTA evidence of carotid T/L or M1 segment MCA occlusion, and at least moderate collaterals by CTA. The trial will determine if endovascular treatment will result in higher rates of favorable outcome compared with standard medical therapy alone. Patient populations that are eligible include those receiving IV tPA, tPA ineligible and unwitnessed onset or wake up strokes with 12 h of last seen normal. The primary end-point, based on intention-to-treat criteria is the distribution of modified Rankin Scale scores at 90 days assessed using a proportional odds model. The projected maximum sample size is 500 subjects. Randomization is stratified under a minimization process using age, gender, baseline NIHSS, baseline ASPECTS (8-10 vs. 6-7), IV tPA treatment and occlusion location (ICA vs. MCA) as covariates. The study will have one formal interim analysis after 300 subjects have been accrued. Secondary end-points at 90 days include the following: mRS 0-1; mRS 0-2; Barthel 95-100, EuroQOL and a cognitive battery. Safety outcomes are symptomatic ICH, major bleeding, contrast nephropathy, total radiation dose, malignant MCA infarction, hemicraniectomy and mortality at 90 days.

Is the Susceptibility Vessel Sign on 3-Tesla Magnetic Resonance T2*-Weighted Imaging a Useful Tool to Predict Recanalization in Intravenous Tissue Plasminogen Activator?

The aim of this study was to investigate the independent factors associated with the absence of recanalization approximately 24 h after intravenous administration of tissue-type plasminogen activator (IV TPA). The previous studies have been conducted using 1.5-Tesla (T) magnetic resonance imaging (MRI). We studied whether the characteristics of 3-T MRI findings were useful to predict outcome and recanalization after IV tPA. Patients with internal carotid artery (ICA) or middle cerebral artery (MCA) (horizontal portion, M1; Sylvian portion, M2) occlusion and treated by IV tPA were enrolled. We studied whether the presence of susceptibility vessel sign (SVS) at M1 and low clot burden score on T2*-weighted imaging (T2*-CBS) on 3-T MRI were associated with the absence of recanalization. A total of 49 patients were enrolled (27 men; mean age, 73.9 years). MR angiography obtained approximately 24 h after IV tPA revealed recanalization in 21 (42.9 %) patients. Independent factors associated with the absence of recanalization included ICA or proximal M1 occlusion (odds ratio, 69.6; 95 % confidence interval, 5.05-958.8, p = 0.002). In this study, an independent factor associated with the absence of recanalization may be proximal occlusion of the cerebral arteries rather than SVS in the MCA or low T2*-CBS on 3-T MRI.

Intra-arterial therapy for acute ischemic stroke

Intra-arterial therapy (IAT) for acute ischemic stroke treatment is evolving. Whereas the efficacy of recanalization with traditional intra-arterial fibrinolysis is relatively poor, mechanically based recanalization with multimodal approaches, stenting and mechanical embolectomy is more effective. Until recently, this has not resulted in overwhelming clinical benefit and has not always equated with reperfusion. The reasons for this are not clearly known but may include inadequate patient selection, poor technique, low operator experience, direct injury from thrombolytics or devices, microvascular occlusions, complications of general anesthesia, or some other unknown factors. Intracerebral hemorrhage still complicates 2-11% of procedures. Large prospective and randomized clinical trials are needed to determine the safety and efficacy of IAT be it pharmacological therapy, embolectomy, stenting, or multimodal therapy. Comparative studies between the newer stent retriever devices and intravenous tissue plasminogen activators may also be needed especially for the 3- to 4.5-hour window.

Stroke in patients with occlusion of the internal carotid artery: options for treatment

Ischemic stroke may occur in patients in whom vascular imaging shows the ipsilateral internal carotid artery (ICA) to be occluded. In younger patients this is often due to carotid artery dissection, while in older people this most likely results from cardiac embolism or thrombosis secondary to high-grade stenosis at the carotid bifurcation. Interventional techniques aim at recanalization of the carotid artery for early restoration of cerebral blood flow and secondary prevention of future strokes. In chronic ICA occlusion the ischemic infarct may be related to hemodynamic compromise. In this situation, extracranial-intracranial bypass surgery was introduced, but its role remains still unclear. Ischemic stroke may also occur in patients with a chronic occlusion of the contralateral ICA. This situation demands the usual stroke treatment, but surgical and neuroradiological interventions face a higher risk than unilateral vascular pathology. Medical treatment supports stroke prevention in carotid artery occlusion.

Thrombolysis for acute ischaemic stroke

BACKGROUND

Most strokes are due to blockage of an artery in the brain by a blood clot. Prompt treatment with thrombolytic drugs can restore blood flow before major brain damage has occurred and improve recovery after stroke in some people. Thrombolytic drugs, however, can also cause serious bleeding in the brain, which can be fatal. One drug, recombinant tissue plasminogen activator (rt-PA), is licensed for use in selected patients within 4.5 hours of stroke in Europe and within three hours in the USA. There is an upper age limit of 80 years in some countries, and a limitation to mainly non-severe stroke in others. Forty per cent more data are available since this review was last updated in 2009.

OBJECTIVES

To determine whether, and in what circumstances, thrombolytic therapy might be an effective and safe treatment for acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched November 2013), MEDLINE (1966 to November 2013) and EMBASE (1980 to November 2013). We also handsearched conference proceedings and journals, searched reference lists and contacted pharmaceutical companies and trialists.

SELECTION CRITERIA

Randomised trials of any thrombolytic agent compared with control in people with definite ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors applied the inclusion criteria, extracted data and assessed trial quality. We verified the extracted data with investigators of all major trials, obtaining additional unpublished data if available.

MAIN RESULTS

We included 27 trials, involving 10,187 participants, testing urokinase, streptokinase, rt-PA, recombinant pro-urokinase or desmoteplase. Four trials used intra-arterial administration, while the rest used the intravenous route. Most data come from trials that started treatment up to six hours after stroke. About 44% of the trials (about 70% of the participants) were testing intravenous rt-PA. In earlier studies very few of the participants (0.5%) were aged over 80 years; in this update, 16% of participants are over 80 years of age due to the inclusion of IST-3 (53% of participants in this trial were aged over 80 years). Trials published more recently utilised computerised randomisation, so there are less likely to be baseline imbalances than in previous versions of the review. More than 50% of trials fulfilled criteria for high-grade concealment; there were few losses to follow-up for the main outcomes.Thrombolytic therapy, mostly administered up to six hours after ischaemic stroke, significantly reduced the proportion of participants who were dead or dependent (modified Rankin 3 to 6) at three to six months after stroke (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.78 to 0.93). Thrombolytic therapy increased the risk of symptomatic intracranial haemorrhage (OR 3.75, 95% CI 3.11 to 4.51), early death (OR 1.69, 95% CI 1.44 to 1.98; 13 trials, 7458 participants) and death by three to six months after stroke (OR 1.18, 95% CI 1.06 to 1.30). Early death after thrombolysis was mostly attributable to intracranial haemorrhage. Treatment within three hours of stroke was more effective in reducing death or dependency (OR 0.66, 95% CI 0.56 to 0.79) without any increase in death (OR 0.99, 95% CI 0.82 to 1.21; 11 trials, 2187 participants). There was heterogeneity between the trials. Contemporaneous antithrombotic drugs increased the risk of death. Trials testing rt-PA showed a significant reduction in death or dependency with treatment up to six hours (OR 0.84, 95% CI 0.77 to 0.93, P = 0.0006; 8 trials, 6729 participants) with significant heterogeneity; treatment within three hours was more beneficial (OR 0.65, 95% CI 0.54 to 0.80, P < 0.0001; 6 trials, 1779 participants) without heterogeneity. Participants aged over 80 years benefited equally to those aged under 80 years, particularly if treated within three hours of stroke.

AUTHORS' CONCLUSIONS

Thrombolytic therapy given up to six hours after stroke reduces the proportion of dead or dependent people. Those treated within the first three hours derive substantially more benefit than with later treatment. This overall benefit was apparent despite an increase in symptomatic intracranial haemorrhage, deaths at seven to 10 days, and deaths at final follow-up (except for trials testing rt-PA, which had no effect on death at final follow-up). Further trials are needed to identify the latest time window, whether people with mild stroke benefit from thrombolysis, to find ways of reducing symptomatic intracranial haemorrhage and deaths, and to identify the environment in which thrombolysis may best be given in routine practice.

Two in One: Endovascular Treatment of Acute Tandem Occlusions in the Anterior Circulation

PURPOSE

Acute major stroke with high-grade stenosis or occlusion of the extracranial internal carotid artery (ICA) and additional intracranial large artery occlusion is increasingly treated with a mechanical endovascular approach by extracranial stenting and intracranial thrombectomy due to poor response to systemic thrombolysis with recombinant tissue plasminogen activator (rtPA). This article presents a single centre cohort of this challenging subtype of stroke, describing the technical procedure and analysing the angiographic and clinical outcome.

METHODS

Clinical and imaging data of all consecutive patients between July 2008 and March 2013 with intracranial artery occlusion in the anterior circulation and additional occlusion or pseudo-occlusion of the cervical ICA were retrospectively analysed with respect to demographical and clinical characteristics. Technical approach, recanalization rate, recanalization time and short-term clinical outcome were determined.

RESULTS

A total of 43 patients with tandem occlusion in the anterior circulation met the inclusion criteria. Out of these, 32 (74.4%) occlusions and 11 (25.6%) pseudo-occlusions of the extracranial ICA with additional occlusion of the distal segment of the ICA in 7.0% (3/43), the M1-segment of the middle cerebral artery (MCA) in 81.4% (35/43) or the M2-segment of the MCA in 11.6% (5/43) of cases were treated with combined endovascular approach including extracranial stenting with angioplasty and intracranial mechanical thrombectomy. In 76.7% of cases, an angiographic recanalization result of 2b or 3 using the Thrombolysis in Cerebral Infarction (TICI) score was achieved. Mean time from first angiographic series to recanalization was 103 min. A modified Rankin Scale (mRS) score of ≤ 2 was achieved in 32.6% at the time of discharge.

CONCLUSION

Endovascular therapy of patients with tandem occlusion in the anterior circulation with emergency extracranial stenting and intracranial mechanical thrombectomy appears to be safe and may lead to a satisfactory angiographic result and clinical outcome.

Recanalization and clinical outcome of occlusion sites at baseline CT angiography in the Interventional Management of Stroke III trial

PURPOSE

To use baseline computed tomographic (CT) angiography to analyze imaging and clinical end points in an Interventional Management of Stroke III cohort to identify patients who would benefit from endovascular stroke therapy.

MATERIALS AND METHODS

The primary clinical end point was 90-day dichotomized modified Rankin Scale (mRS) score. Secondary end points were 90-day mRS score distribution and 24-hour recanalization. Prespecified subgroup was baseline proximal occlusions (internal carotid, M1, or basilar arteries). Exploratory analyses were subsets with any occlusion and specific sites of occlusion (two-sided α = .01).

RESULTS

Of 656 subjects, 306 (47%) underwent baseline CT angiography or magnetic resonance angiography. Of 306, 282 (92%) had arterial occlusions. At baseline CT angiography, proximal occlusions (n = 220) demonstrated no difference in primary outcome (41.3% [62 of 150] endovascular vs 38% [27 of 70] intravenous [IV] tissue-plasminogen activator [tPA]; relative risk, 1.07 [99% confidence interval: 0.67, 1.70]; P = .70); however, 24-hour recanalization rate was higher for endovascular treatment (n = 167; 84.3% [97 of 115] endovascular vs 56% [29 of 52] IV tPA; P < .001). Exploratory subgroup analysis for any occlusion at baseline CT angiography did not demonstrate significant differences between endovascular and IV tPA arms for primary outcome (44.7% [85 of 190] vs 38% [35 of 92], P = .29), although ordinal shift analysis of full mRS distribution demonstrated a trend toward more favorable outcome (P = .011). Carotid T- or L-type occlusion (terminal internal carotid artery [ICA] with M1 middle cerebral artery and/or A1 anterior cerebral artery involvement) or tandem (extracranial or intracranial) ICA and M1 occlusion subgroup also showed a trend favoring endovascular treatment over IV tPA alone for primary outcome (26% [12 of 46] vs 4% [one of 23], P = .047).

CONCLUSION

Significant differences were identified between treatment arms for 24-hour recanalization in proximal occlusions; carotid T- or L-type and tandem ICA and M1 occlusions showed greater recanalization and a trend toward better outcome with endovascular treatment. Vascular imaging should be mandated in future endovascular trials to identify such occlusions. Online supplemental material is available for this article.