Bridging Intravenous–Intra-Arterial Rescue Strategy Increases Recanalization and the Likelihood of a Good Outcome in Nonresponder Intravenous Tissue Plasminogen Activator-Treated Patients

A Review of the use of Transcranial Doppler Waveform Morphology for Acute Stroke Assessment

Acute ischemic stroke is a source of long-term disability in the United States, of which a large portion of cases are a result of large vessel occlusion (LVO). LVO strokes have high rates of morbidity and mortality due to difficulty of treatments in achieving recanalization. Recently, however, results of randomized clinical trials have shown that treatment options are expanding in both availability and efficacy. As these methods of intervention become more optimal, so must the preceding methods of assessment. Transcranial Doppler (TCD) ultrasound is a non-invasive method of evaluating cerebral hemodynamics, and has a long history in stroke assessment. Despite the importance of information provided by a TCD exam, its utilization in the acute stroke workflow has remained low because of its dependence on expert analysis. Here, we review the evolution of morphological analysis of TCD waveforms for the indication, localization, and monitoring of acute LVO.

Acute ischemic stroke thrombi have an outer shell that impairs fibrinolysis

OBJECTIVES

Thrombi responsible for large vessel occlusion (LVO) in the setting of acute ischemic stroke (AIS) are characterized by a low recanalization rate after IV thrombolysis. To test whether AIS thrombi have inherent common features that limit their susceptibility to thrombolysis, we analyzed the composition and ultrastructural organization of AIS thrombi causing LVO.

METHODS

A total of 199 endovascular thrombectomy-retrieved thrombi were analyzed by immunohistology and scanning electron microscopy (SEM) and subjected to ex vivo thrombolysis assay. The relationship between thrombus organization and thrombolysis resistance was further investigated in vitro using thrombus produced by recalcification of citrated whole blood.

RESULTS

SEM and immunohistology analyses revealed that, although AIS thrombus composition and organization was highly heterogeneous, AIS thrombi shared a common remarkable structural feature in the form of an outer shell made of densely compacted thrombus components including fibrin, von Willebrand factor, and aggregated platelets. In vitro thrombosis experiments using human blood indicated that platelets were essential to the formation of the thrombus outer shell. Finally, in both AIS and in vitro thrombi, the thrombus outer shell showed a decreased susceptibility to tissue plasminogen activator-mediated thrombolysis as compared to the thrombus inner core.

INTERPRETATION

Irrespective of their etiology and despite their heterogeneity, intracranial thrombi causing LVO have a core shell structure that influences their susceptibility to thrombolysis.

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

Background and Aims

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

Methods

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

Results

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

Conclusions

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

Reperfusion therapy in acute ischemic stroke: dawn of a new era?

Following the success of recent endovascular trials, endovascular therapy has emerged as an exciting addition to the arsenal of clinical management of patients with acute ischemic stroke (AIS). In this paper, we present an extensive overview of intravenous and endovascular reperfusion strategies, recent advances in AIS neurointervention, limitations of various treatment paradigms, and provide insights on imaging-guided reperfusion therapies. A roadmap for imaging guided reperfusion treatment workflow in AIS is also proposed. Both systemic thrombolysis and endovascular treatment have been incorporated into the standard of care in stroke therapy. Further research on advanced imaging-based approaches to select appropriate patients, may widen the time-window for patient selection and would contribute immensely to early thrombolytic strategies, better recanalization rates, and improved clinical outcomes.

Streamlining Workflow for Endovascular Mechanical Thrombectomy: Lessons Learned from a Comprehensive Stroke Center

BACKGROUND

Recently, 5 randomized controlled trials confirmed the superiority of endovascular mechanical thrombectomy (EMT) to intravenous thrombolysis in acute ischemic stroke with large-vessel occlusion. The implication is that our health systems would witness an increasing number of patients treated with EMT. However, in-hospital delays, leading to increased time to reperfusion, are associated with poor clinical outcomes. This review outlines the in-hospital workflow of the treatment of acute ischemic stroke at a comprehensive stroke center and the lessons learned in reduction of in-hospital delays.

METHODS

The in-hospital workflow for acute ischemic stroke was described from prehospital notification to femoral arterial puncture in preparation for EMT. Systematic review of literature was also performed with PubMed.

RESULTS

The implementation of workflow streamlining could result in reduction of in-hospital time delays for patients who were eligible for EMT. In particular, time-critical measures, including prehospital notification, the transfer of patients from door to computed tomography (CT) room, initiation of intravenous thrombolysis in the CT room, and the mobilization of neurointervention team in parallel with thrombolysis, all contributed to reduction in time delays.

CONCLUSIONS

We have identified issues resulting in in-hospital time delays and have reported possible solutions to improve workflow efficiencies. We believe that these measures may help stroke centers initiate an EMT service for eligible patients.

Scientific Rationale for the Inclusion and Exclusion Criteria for Intravenous Alteplase in Acute Ischemic Stroke

Purpose—

To critically review and evaluate the science behind individual eligibility criteria (indication/inclusion and contraindications/exclusion criteria) for intravenous recombinant tissue-type plasminogen activator (alteplase) treatment in acute ischemic stroke. This will allow us to better inform stroke providers of quantitative and qualitative risks associated with alteplase administration under selected commonly and uncommonly encountered clinical circumstances and to identify future research priorities concerning these eligibility criteria, which could potentially expand the safe and judicious use of alteplase and improve outcomes after stroke.

Methods—

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council’s Scientific Statement Oversight Committee and the American Heart Association’s Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge and, when appropriate, formulated recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on and approved the final version of this document. The document underwent extensive American Heart Association internal peer review, Stroke Council Leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee.

Results—

After a review of the current literature, it was clearly evident that the levels of evidence supporting individual exclusion criteria for intravenous alteplase vary widely. Several exclusionary criteria have already undergone extensive scientific study such as the clear benefit of alteplase treatment in elderly stroke patients, those with severe stroke, those with diabetes mellitus and hyperglycemia, and those with minor early ischemic changes evident on computed tomography. Some exclusions such as recent intracranial surgery are likely based on common sense and sound judgment and are unlikely to ever be subjected to a randomized, clinical trial to evaluate safety. Most other contraindications or warnings range somewhere in between. However, the differential impact of each exclusion criterion varies not only with the evidence base behind it but also with the frequency of the exclusion within the stroke population, the probability of coexistence of multiple exclusion factors in a single patient, and the variation in practice among treating clinicians.

Intravenous tissue plasminogen activator before endovascular treatment increases symptomatic intracranial hemorrhage in patients with occlusion of the middle cerebral artery second division: subanalysis of the RESCUE-Japan Registry

INTRODUCTION

No previous study has investigated the relationship between intravenous tissue plasminogen activator (IV t-PA) and intracranial hemorrhage (ICH) according to the location of vessel occlusion. The aim of the present study was to investigate the relationship between preprocedural IV t-PA and endovascular treatment (EVT) and ICH according to the location of occlusion using data from the nationwide prospective registry of acute cerebral large vessel occlusion (LVO), the RESCUE-Japan Registry.

METHODS

Among 1442 patients with acute LVO enrolled in the registry, we examined 410 patients who received EVT. Patients were divided into the following four groups according to the location of occlusion: the internal carotid artery (ICA), middle cerebral artery first division (M1), middle cerebral artery second division (M2), and vertebral artery (VA)/basilar artery (BA) groups.

RESULTS

A total of 399 patients in whom the occlusion was located in these vessels were finally included. Any ICH (aICH) was identified in 127 (30.9%) patients, and symptomatic ICH (sICH) was identified in 20 (4.9%). Preprocedural IV t-PA did not increase the incidence of aICH in any group and tended to increase the incidence of sICH in only the M2 group. In multivariate analysis of the M2 group, IV t-PA was an independent risk factor for sICH.

CONCLUSION

Preprocedural IV t-PA did not increase the incidence of ICH in total, but could increase the incidence of sICH in those with M2 occlusion. IV t-PA before EVT may be an independent risk factor for sICH in patients with M2 occlusion.

Strokes in the anterior circulation: comparison between bridging and intravenous thrombolysis

BACKGROUND AND PURPOSE

To compare safety and efficacy of bridging approach with intravenous (IV) thrombolysis in patients with acute anterior strokes and proximal occlusions.

PATIENTS AND METHODS

Consecutive patients with ischemic anterior strokes admitted within a 4 h 30 min window in two different centers were included. The first center performed IV therapy (alteplase 0.6 mg/kg) during 30 min and, in absence of clinical improvement, mechanical thrombectomy with flow restoration using a Solitaire stent (StS); the second carried out IV thrombolysis (alteplase 0.9 mg/kg) alone. Only T, M1 or M2 occlusions present on CT angiography were considered. Endpoints were clinical outcome and mortality at 3 months.

RESULTS

There were 63 patients in the bridging and 163 in the IV group. No significant differences regarding baseline characteristics were observed. At 3 months, 46% (n = 29) of the patients treated in the combined and 23% (n = 38) of those treated in the IV group had a modified Rankin scale (mRS) of 0-1 (P < 0.001). A statistical significant difference was observed for all sites of occlusion. In a logistic regression model, National Institute of Health Stroke Scale (NIHSS) and bridging therapy were independent predictors of good outcome (respectively, P = 0.001 and P = 0.0018). Symptomatic hemorrhage was documented in 6.3% vs 3.7% in the bridging and in the IV group, respectively (P = 0.32). There was no difference in mortality.

CONCLUSIONS

Our results suggest that patients treated with a bridging approach were more likely to have minimal or no deficit at all at 3 months as compared to the IV treated group.

Reperfusion therapies for acute ischemic stroke: an update

Acute ischemic stroke is a major cause of morbidity and mortality in developed countries. Intravenous thrombolysis with tissue plasminogen activator (tPA) within 4.5 hours of symptoms onset significantly improves clinical outcomes in patients with acute ischemic stroke. This narrow window for treatment leads to a small proportion of eligible patients to be treated. Intravenous or intra-arterial trials, combined intravenous/intra-arterial trials, and newer devices to mechanically remove the clot from intracranial arteries have been investigated or are currently being explored to increase patient eligibility and to improve arterial recanalization and clinical outcome. New retrievable stent-based devices offer higher revascularization rates with shorter time to recanalization and are now generally preferred to first generation thrombectomy devices such as Merci Retriever or Penumbra System. These devices have been shown to be effective for opening up occluded vessels in the brain but its efficacy for improving outcomes in patients with acute stroke has not yet been demonstrated in a randomized clinical trial. We summarize the results of the major systemic thrombolytic trials and the latest trials employing different endovascular approaches to ischemic stroke.

Intra-arterial therapy as a rescue strategy after clinically failed intravenous thrombolysis may increase the likelihood of a good outcome in patients with severe ischaemic stroke. A retrospective two centre study

The purpose of this study was to evaluate the efficacy and safety of intra-arterial therapy as a rescue strategy after clinically failed intravenous thrombolysis (IVT) in acute ischaemic stroke patients. We conducted a retrospective analysis of consecutive acute ischaemic stroke patients treated with rescue therapy. The results from this study group were compared with those obtained from a control group consisting of 260 consecutive patients treated with IVT alone. The study group consisted of 52 patients with a mean age of 63 years and a median NIHSS score at admission of 17. Recanalization was achieved in 92% with a symptomatic haemorrhage rate of 9.6%. Rescue patients admitted with a severe stroke (NIHSS score >12) had a significantly better outcome at 90 days compared to patients with the same score but treated with IVT alone. No difference was seen for patients with a lower score at admission. This study indicates that rescue therapy may increase the proportion of patients with independent outcome if presenting with a severe stroke (NIHSS score >12) without increasing the rate of symptomatic haemorrhage.

To do or not to do; dilemma of intra-arterial revascularization in acute ischemic stroke

Background

There has still been lack of evidence for definite imaging criteria of intra-arterial revascularization (IAR). Therefore, IAR selection is left largely to individual clinicians. In this study, we sought to investigate the overall agreement of IAR selection among different stroke clinicians and factors associated with good agreement of IAR selection.

Methods

From the prospectively registered data base of a tertiary hospital, we identified consecutive patients with acute ischemic stroke. IAR selection based on the provided magnetic resonance imaging (MRI) results and clinical information were independently performed by 5 independent stroke physicians currently working at 4 different university hospitals. MRI results were also reviewed by 2 independent experienced neurologists blinded to clinical data and physicians' IAR selection. The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) was calculated on initial DWI and MTT. We arbitrarily used ASPECTS differences between DWI and MTT (D-M ASPECTS) to quantitatively evaluate mismatch.

Results

The overall interobserver agreement of IAR selection was fair (kappa = 0.398). In patients with DWI-ASPECTS >6, interobserver agreement was moderate to substantial (0.398–0.620). In patients with D-M ASPECTS >4, interobserver agreement was moderate to almost perfect (0.532–1.000). Patients with higher DWI or D-M ASPECTS had better agreement of IAR selection.

Conclusion

Our study showed that DWI-ASPSECTS >6 and D-M ASPECTS >4 had moderate to substantial agreement of IAR selection among different stroke physicians. However, there is still poor agreement as to whether IAR should not be performed in patients with lower DWI and D-M ASPECTS.

Intravenous thrombolysis of basilar artery occlusion: thrombus length versus recanalization success

BACKGROUND AND PURPOSE

In middle cerebral artery occlusion, probability of recanalization after intravenous tissue-type plasminogen activator thrombolysis (IVT) was reported to drop <1% for thrombi exceeding 8 mm. We aimed to evaluate the effect of thrombus length and location on success of recanalization after IVT in basilar artery occlusion.

METHODS

We evaluated 164 consecutive patients with angiography-proven basilar artery occlusion and available thrombus length. We excluded 24 patients who underwent endovascular treatment. All included patients (n=140) received IVT. Thrombolysis in myocardial infarction 2 to 3 was considered as successful recanalization.

RESULTS

Of the 140 included patients, 37 (26.4%) lacked post-treatment angiography, mostly because of early death. Of the remaining 103 patients, those with recanalization had shorter thrombi (median, 5.5 mm and mean, 9.7 mm) when compared with those with nonrecanalized (median, 15.0 mm and mean, 16.6 mm; P<0.001). Thrombi shorter than 10 mm had 70% to 80% probability of recanalization, whereas 10 to 20 mm, 20 to 30 mm, and >30 mm long thrombi had probabilities of 50% to 70%, 30% to 50%, and 20% to 30%, respectively. Patients with thrombi <10 mm (n=52) and recanalization had more frequently top-of-the basilar (92.5%) and less frequently caudal or midbasilar (7.5%) clot location (P=0.01). In multivariable analysis, thrombus length was independently associated with recanalization (P=0.001). Their relationship remained linear across all lengths.

CONCLUSIONS

Although recanalization of basilar artery occlusion with IVT depends on thrombus length, its probability even in patients with thrombi >30 mm (20%-30%) was substantially higher than minimal recanalization of middle cerebral artery thrombi exceeding 8 mm. There was no threshold length, beyond which basilar artery occlusion recanalization with IVT could ad hoc be deemed hopeless.

Utility of a rescue endovascular therapy for the treatment of major strokes refractory to full-dose intravenous thrombolysis

OBJECTIVE

Large artery occlusion (LAO) in patients with major stroke predicts poor revascularization by intravenous thrombolysis (IVT) and more likely results in a poor outcome. We focused on the effects of intra-arterial thrombolysis (IAT) and endovascular mechanical recanalization (EMR) as rescue therapies in major strokes refractory to IVT.

METHODS

A retrospective analysis of 87 patients (National Institutes of Health Stroke Scale >20), who did not respond to full-dose IVT due to LAO, was performed based on their endovascular therapy status. IAT was performed as an intraclot infusion of alteplase, and EMR was provided by the Solitaire device™ (Covidien, Dubin, Ireland). The recanalization and 3-month outcome rates after IAT/EMR were correlated with a group of patients who were scheduled to receive endovascular treatment but who underwent only IVT.

RESULTS

We achieved successful recanalization by IAT and EMR in 68.7% and 76.1% of patients, respectively. Despite no significant differences in mortality between IAT and EMR, a trend towards better outcomes after IAT and a statistically significant increase for outcome-modified Rankin scale (mRS) 0-3 (45.7%) and mRS 0-2 (34.9%) after EMR was noted when compared with IVT. The degree of recanalization did not correlate with the functional results except for the good-moderate outcome after successful recanalization by EMR.

CONCLUSION

EMR by the Solitaire device is a safe and beneficial method for the rescue treatment of patients with major stroke whose neurological status does not improve and who fail to recanalize the LAO after a 1-h full dose of IVT.

ADVANCES IN KNOWLEDGE

The article verifies efficiency of the Solitaire device in major strokes.

Current Reperfusion Strategies for Acute Stroke

Stroke is the most common cause of permanent disability, the second most common cause of dementia, and the third most common cause of death in the Western world. The treatment of affected patients is a challenge because intravenous (IV) thrombolysis is often ineffective. IV thrombolysis on its own leads to a favorable clinical outcome in only 15% to 25% in patients with large-artery occlusion. Current reperfusion therapies enable high recanalization rates, high rate of favorable clinical outcome, and low complication rates. However, to achieve good clinical results, appropriate patient selection and the use of optimized stroke management system are obligate.

Endovascular therapy in hyperacute ischaemic stroke: history and current status

This is a literature review on to the use of endovascular therapy in hyperacute ischaemic stroke secondary to large vessel occlusion (LVO). The prognosis for LVO is generally poor and the efficacy of intravenous tissue plasminogen activator (IV TPA) in the treatment of this subtype of stroke is questionable. It is well documented that recanalisation is associated with improved outcomes but IV TPA has limited efficacy in LVO recanalisation and the complication rates are higher for IV TPA in this stroke subset. Improved recanalisation rates have been demonstrated with intra-arterial TPA and first and second generation mechanical techniques but the rate of favourable outcome has not overtly mirrored this improvement. Several controversial trials using these early techniques have recently been published but fail to reflect modern practice which centres on the use of stent-retriever technology. This has been proven to be superior to older techniques. Not only are recanalisation rates higher, but the speed of recanalisation is greater and clinical results are improved. Multiple observational studies demonstrate consistently high rates of LVO recanalisation; TICI 2b/3 in the order of 65-95% and, rates of favourable outcome (mRS 0-2) in the order of 55% (42.5-77%) in clinically moderate to severe stroke with complicating symptomatic haemorrhage in the order of 1.5-15%. A major factor determining outcome is time to treatment but success has been demonstrated using these devices with bridging therapy, after IV TPA failure or as a stand-alone treatment.

The role of dual energy CT in differentiating between brain haemorrhage and contrast medium after mechanical revascularisation in acute ischaemic stroke

OBJECTIVES

To assess the feasibility of dual energy computed tomography (DE-CT) in intra-arterially treated acute ischaemic stroke patients to discriminate between contrast extravasation and intracerebral haemorrhage.

METHODS

Thirty consecutive acute ischaemic stroke patients following intra-arterial treatment were examined with DE-CT. Simultaneous imaging at 80 kV and 140 kV was employed with calculation of mixed images. Virtual unenhanced non-contrast (VNC) images and iodine overlay maps (IOM) were calculated using a dedicated brain haemorrhage algorithm. Mixed images alone, as "conventional CT", and DE-CT interpretations were evaluated and compared with follow-up CT.

RESULTS

Eight patients were excluded owing to a lack of follow-up or loss of data. Mixed images showed intracerebral hyperdense areas in 19/22 patients. Both haemorrhage and residual contrast material were present in 1/22. IOM suggested contrast extravasation in 18/22 patients; in 16/18 patients this was confirmed at follow-up. The positive predictive value (PPV) of mixed imaging alone was 25 %, with a negative predictive value (NPV) of 91 % and accuracy of 63 %. The PPV for detection of haemorrhage with DE-CT was 100 %, with an NPV of 89 % and accuracy improved to 89 %.

CONCLUSIONS

Dual energy computed tomography improves accuracy and diagnostic confidence in early differentiation between intracranial haemorrhage and contrast medium extravasation in acute stroke patients following intra-arterial revascularisation.

KEY POINTS

• Contrast material and haemorrhage have similar density on conventional 120-kV CT. • Contrast material hinders interpretation of CT in stroke patients after recanalisation. • Iodine and haemorrhage have different attenuation at lower kVs. • Dual energy CT improves accuracy in early differentiation of haemorrhage and contrast extravasation. • Early differentiation between iodine and haemorrhage helps to initiate therapy promptly.

Mechanical thrombectomy - an alternative treatment option in a patient with acute ischemic stroke and multiple contraindications for systemic thrombolysis: a case report

Introduction

Acute ischemic stroke is a common cause of disability and death in developed countries. Standard therapy for patients who present within 4.5 hours from the onset of symptoms is intravenous thrombolysis if contraindications such as oral anticoagulation, cancer or recent surgery are ruled out. Apart from that, mechanical recanalization is a new treatment option for patients with occlusion of major cerebral arteries as a cause of ischemic stroke.

Case presentation

In this case report we describe a 55-year-old Caucasian man with a right hemispheric ischemic syndrome who presented in time but who had multiple contraindications against systemic thrombolysis. He was then treated with mechanical recanalization and recovered. On discharge from the hospital he had only a slight left-sided facial paresis and discrete impairment of motion smoothness in his left hand.

Conclusion

We conclude that multimodal imaging should be performed in all patients with an acute onset of neurological symptoms suspicious of ischemic stroke, even if they have contraindications against an intravenous thrombolytic treatment.

Validation of the DRAGON Score in 12 Stroke Centers in Anterior and Posterior Circulation

Background and Purpose—

The DRAGON score predicts functional outcome in the hyperacute phase of intravenous thrombolysis treatment of ischemic stroke patients. We aimed to validate the score in a large multicenter cohort in anterior and posterior circulation.

Methods—

Prospectively collected data of consecutive ischemic stroke patients who received intravenous thrombolysis in 12 stroke centers were merged (n=5471). We excluded patients lacking data necessary to calculate the score and patients with missing 3-month modified Rankin scale scores. The final cohort comprised 4519 eligible patients. We assessed the performance of the DRAGON score with area under the receiver operating characteristic curve in the whole cohort for both good (modified Rankin scale score, 0–2) and miserable (modified Rankin scale score, 5–6) outcomes.

Results—

Area under the receiver operating characteristic curve was 0.84 (0.82–0.85) for miserable outcome and 0.82 (0.80–0.83) for good outcome. Proportions of patients with good outcome were 96%, 93%, 78%, and 0% for 0 to 1, 2, 3, and 8 to 10 score points, respectively. Proportions of patients with miserable outcome were 0%, 2%, 4%, 89%, and 97% for 0 to 1, 2, 3, 8, and 9 to 10 points, respectively. When tested separately for anterior and posterior circulation, there was no difference in performance ( P =0.55); areas under the receiver operating characteristic curve were 0.84 (0.83–0.86) and 0.82 (0.78–0.87), respectively. No sex-related difference in performance was observed ( P =0.25).

Conclusions—

The DRAGON score showed very good performance in the large merged cohort in both anterior and posterior circulation strokes. The DRAGON score provides rapid estimation of patient prognosis and supports clinical decision-making in the hyperacute phase of stroke care (eg, when invasive add-on strategies are considered).

Early Anticipation of Candidacy for Intra-Arterial Reperfusion Therapy Based on Baseline Clinical Stroke Subtypes: Comparison with Multiparametric MRI Taken within 4.5 Hours from Stroke Onset

Background

The decision to proceed with intra-arterial (IA) reperfusion therapy is typically made late in the course of in-hospital treatment for acute ischemic stroke. Early anticipation of candidacy for IA reperfusion therapy based on clinical stroke subtypes would be useful for guiding stroke management. The aim of this study was to investigate the relationship between the clinical Oxfordshire Community Stroke Project (OCSP) classification and MRI results taken within a 4.5-hour time window from stroke onset, with the hypothesis that the persistence of major arterial occlusion and extended ischemic penumbra, key criteria for proceeding with IA reperfusion therapy, would be distinctive between the clinical stroke subtypes.

Methods

A total of 161 patients with acute ischemic stroke in the anterior circulation were included in this study. All patients were treated with intravenous alteplase, and MRI scans were performed following alteplase initiation. Prior to treatment, the patients were categorized, based on the OCSP classification scheme, as having total anterior circulation infarcts (TACI), partial anterior circulation infarcts (PACI), or lacunar infarcts (LACI). The relationship between OCSP subtypes, MRI parameters, and clinical variables was analyzed.

Results

Overall, 40/161 patients (24.8%) were candidates for IA rescue reperfusion. With respect to the classification, 30/69 TACI (43.5%), 6/33 PACI (18.2%), and 4/59 LACI patients (6.8%) were candidates (p < 0.001). Major arterial occlusion was found in 56/161 patients (34.8%), and 46/69 TACI (66.7%), 6/33 PACI (18.2%), and 4/59 LACI patients (6.8%) had a major arterial occlusion (p < 0.001). A perfusion-diffusion mismatch greater than 20% was found in 85/161 patients (52.8%). More specifically, 40/69 TACI (58.0%), 25/33 PACI (75.8%), and 20/59 LACI patients (33.9%) had a perfusion-diffusion mismatch (p < 0.001). However, in terms of the total area of mismatch, 66.0% of patients with ASPECTS_DWI-PWI ≥2 (Alberta Stroke Program Early CT Score) were classified as TACI patients (p < 0.001) and of the patients with ASPECTS_DWI-PWI ≥3, 74.3% were classified as TACI patients (p < 0.001). Relative to candidates for IA rescue reperfusion, the clinical TACI group showed 75.0% sensitivity, 67.8% specificity, a positive predictive value of 43.5%, and a negative predictive value of 89.1%.

Conclusions

In this study, patients classified as having clinical TACI were significantly more likely to be candidates for IA rescue reperfusion. Additionally, they incurred a higher incidence of persistent major arterial occlusion and had a penumbra area that was significantly larger than normal. Therefore, clinical OCSP can be used as an ‘early warning system’ for IA reperfusion candidacy, which can allow for advanced preparation of IA therapy and theoretically shorten treatment time and reduce infarction.

Impact of Onset-to-Reperfusion Time on Stroke Mortality

Background—

Onset-to-reperfusion time has been reported to be associated with clinical prognosis. However, its impact on mortality remained to be assessed. Using a collaborative pooled analysis, we examined whether early mortality after successful endovascular treatment is time dependent.

Methods and Results—

In a collaborative pooled analysis of 7 endovascular databases, we assessed the impact of onset-to-reperfusion time in large-artery occlusion (internal carotid artery or middle cerebral artery) on outcomes. Successful reperfusion was defined as complete or partial restoration of blood flow within 8 hours from symptom onset. Primary outcome was 90-day all-cause mortality. Secondary outcomes included 90-day favorable outcome (modified Rankin Scale score, 0–2), 90-day excellent outcome (modified Rankin Scale score, 0–1), and occurrence of any intracerebral hemorrhage within 24 to 36 hours after treatment. A total of 480 cases with successful reperfusion (median time, 285 minutes) contributed to the present pooled analysis (120 with internal carotid artery occlusion and 360 with isolated middle cerebral artery occlusion). Increasing onset-to-reperfusion time was associated with an increased rate of mortality and intracerebral hemorrhage and with a decreased rate of favorable and excellent outcomes, without heterogeneity across studies. The adjusted odds ratio for each 30-minute time increase was 1.21 (95% confidence interval, 1.09–1.34; P <0.001) for mortality, 0.79 (95% confidence interval, 0.72–0.87) for favorable outcome, 0.78 (95% confidence interval, 0.71–0.86) for excellent outcome, and 1.21 (95% confidence interval, 1.10–1.33) for intracerebral hemorrhage.

Conclusion—

Onset-to-reperfusion time affects mortality and favorable outcome and should be considered the main goal in acute stroke patient management.

Unanswered questions in thrombolytic therapy for acute ischemic stroke

This article reviews some of the current literature in support or against extension of the intravenous tissue plasminogen activator window, use of intra-arterial therapy or devices, as well alternative pharmacologic therapies that may extend the window for treatment of patients with acute ischemic stroke, with consideration of the relative risk of thrombolytic complications, factors for worse outcomes, and unclear stroke onset, as seen in patients with wake-up stroke. The issue of newer concomitant antithrombotic therapies as they affect the decision for acute ischemic stroke thrombolytic therapy is also explored.

Outcome of ischemic stroke patients with serious post-thrombolysis neurological deficits

OBJECTIVES

To identify factors associated with favorable outcome in ischemic stroke patients having considerable post-thrombolytic neurological deficits but without endovascular treatment.

MATERIALS AND METHODS

We registered 1427 consecutive thrombolysis-treated ischemic stroke patients, of which 473 (33%) had ≥8 NIH Stroke Scale (NIHSS) points after thrombolysis but did not undergo any further rescue intervention. We dichotomized them based on 3-month modified Rankin Scale (mRS) to those with favorable (mRS 0-2, n = 126, 27%) and unfavorable (mRS 3-6, n = 347) outcome. Univariate and multivariable methods tested associations of baseline and post-thrombolysis parameters with outcome.

RESULTS

Lower post-thrombolysis NIHSS score and younger age had strongest association with favorable outcome. Most of patients with post-thrombolytic NIHSS score ≥11 achieved unfavorable outcome. In contrast, half of patients with favorable outcome had post-thrombolytic NIHSS≤10, and 62% of patients younger than 75 years and having post-thrombolytic NIHSS 8-9 achieved favorable outcome. Weaker independent association was observed for blood glucose level and baseline diastolic blood pressure.

CONCLUSIONS

As expected, NIHSS score and patient age showed the strongest association with final outcome in a subpopulation of patients having considerable post-thrombolytic neurological deficit. A relatively high proportion of patients with post-thrombolytic NIHSS 8-9 (10) achieved a favorable 3-month outcome without any further intervention.

Mechanical recanalization with flow restoration in acute ischemic stroke: the ReFlow (mechanical recanalization with flow restoration in acute ischemic stroke) study

OBJECTIVES

This study sought to assess the feasibility and safety of a recently described technique of mechanical recanalization with the help of a stent-like device.

BACKGROUND

In the special group of acute stroke patients with an intracranial large vessel occlusion, intravenous tissue-type plasminogen activator on its own leads to a good clinical outcome (mRS ≤ 2) in only 15% to 25% of cases. The aforementioned technique of mechanical recanalization showed very promising clinical results.

METHODS

Forty patients presenting within 6 h from stroke symptom onset were enrolled. Mechanical recanalization was performed using a Solitaire FR revascularization device. The primary endpoint of the study was the clinical outcome rated with the help of the modified Rankin Scale (mRS) after 90 days.

RESULTS

Twenty-four patients (60%) showed a good clinical outcome (mRS ≤ 2) at 90 days. One symptomatic hemorrhage was detected on follow-up computed tomography. The death rate was 12.5% (5 patients). Successful recanalization (Thrombolysis In Cerebral Infarction score ≥ 2b) of the target vessel was achieved in 95% of the patients with a mean of 1.8 runs with the device.

CONCLUSIONS

The ReFlow (Mechanical Recanalization With Flow Restoration in Acute Ischemic Stroke) study shows that mechanical recanalization with flow restoration is highly effective in stroke patients with a large intracranial vessel occlusion presenting within 4.5 h after symptom onset. (Mechanical Recanalization With Flow Restoration in Acute Ischemic Stroke [ReFlow]; NCT01210729).

Emergency Transfer of Acute Stroke Patients within the East Saxony Telemedicine Stroke Network: A Descriptive Analysis

Background

Telemedicine may facilitate the selection of stroke patients who require emergency transfer to a comprehensive stroke center to receive additional therapies other than intravenous tissue plasminogen activator.

Aims and/or hypothesis

We sought to analyze frequency, patient characteristics, and specific therapies among emergently transferred patients within the telemedical Stroke East Saxony Network.

Methods

We reviewed consecutive patients who were transferred emergently from remote spoke sites to hub sites. Certified stroke neurologists performed teleconsultations 24/7, with access to high-speed videoconferencing and transfer of brain images. Emergent transfers were initiated when considered necessary by the stroke neurologist.

Results

In 2009 and 2010, we conducted 1413 teleconsultations and subsequently recommended transfer in 339 (24%) patients [mean age 64 ± 14 years, 54% males, median National Institutes of Health Stroke Scale score 5 (interquartile range, IQR 12). The mean teleconsultation-to-arrival time was 1·7 ± 0·8 h (median 1·6 h). Sixty-eight (20%) transferred patients had a nonstroke diagnosis. The remaining 271 (80%) patients had stroke diagnoses [ischemic stroke, 114 (34%); transient ischemic attack, 8 (2%); and intracranial haemorrhage, 149 (44%)]. Forty (35%) ischemic stroke patients received tissue plasminogen activator at spoke sites (‘drip and ship’). Of the 240 stroke patients emergently transferred to the main hub site, 119 (49·6%) received at least one specific stroke therapy.

Conclusion

A remarkable number of stroke patients can be transferred within a telemedical network to enable the delivery of specific stroke therapies that require advanced multispecialty expertise. Whether associated logistic efforts and costs have an impact on patients' clinical outcomes needs to be evaluated.

The safety and efficacy of bridging full-dose IV-IA thrombolysis in acute ischemic stroke patients with MCA occlusion: a comparison with IV thrombolysis alone

AIMS

Early recanalization of the occluded cerebral artery is substantial for clinical improvement in acute ischemic stroke (IS) patients. The rate of achieved recanalizations using IVT is low. The aim of this study was to compare the safety and efficacy of bridging full-dose intravenous-intraarterial (IV-IA) thrombolysis to IVT alone in acute IS patients with occluded MCA.

METHODS

Seventy-nine consecutive IS patients with MCA occlusion were treated either with IVT alone (historic controls, Group 1) or with full-dose IV-IA thrombolysis (Group 2). Stroke severity was evaluated using NIHSS, achieved recanalizations using transcranial Doppler (Group 1) or angiography (Group 2). Occurrence of ICH including SICH was evaluated after 24 hours. 90-day clinical outcome was evaluated using modified Rankin Scale (mRS).

RESULTS

Group 1 consisted of 50 patients (24 males, mean age 70.8±10.2 years) and Group 2 of 29 patients (14 males, mean age 67.8±10.0 years). No difference was found in the initial NIHSS (median 16 vs. 17) and other baseline parameters including time from stroke onset to IVT. Patients treated with bridging therapy had a higher number of achieved MCA recanalization (75.9 vs. 32.0%, P=0.0002), similar number of SICH (6.0 vs. 6.9%, P=1.000) and 34.5% of them achieved mRS 0-2 versus 28.0% of patients treated with IVT (P=0.546). Patients with shorter TR had significantly better clinical outcome (P=0.019).

CONCLUSION

Bridging IV-IA thrombolysis seems to be safe and more effective than IVT alone in acute stroke patients with MCA occlusion.

The 2010 British Association of Stroke Physicians Survey of interventional treatments for stroke in the United Kingdom

INTRODUCTION

The UK National Stroke Strategy (Department of Health 2007) states that patients should have access to a stroke service with neurointerventional capacity. This survey was conducted by the Clinical Standards Committee of the British Association of Stroke Physicians to get a snapshot of the availability of interventional treatments for stroke in the United Kingdom.

METHODS

Questionnaires covering availability of endovascular treatments for stroke, e.g. intra-arterial thrombolysis and mechanical thrombectomy, were emailed to all British Association of Stroke Physicians members in October 2010. Where more than one response was received from the same hospital, the data were only entered once. If there was a discrepancy between different respondents for the same hospital, details were cross-checked with the respondents to ensure accuracy.

RESULTS

Responses were received from 58 hospitals in England, Scotland, Wales, and Northern Ireland. Intra-arterial thrombolysis and/or mechanical thrombectomy were available in 23 hospitals. Of these, three had not performed any procedures in 2010. Twenty centres had conducted a mean (range) of eight (2-20) procedures during the 10-month period. Thirty-five hospitals were not offering endovascular treatments. Sixteen of these were not referring patients to centres which could provide interventional treatments. Hospitals offering endovascular treatments had a mean (range) of 5.2 (2-12) stroke physicians, 2.3 (0-4) interventional neuroradiologists, and 3.6 (0-9) noninterventional neuroradiologists. Only two hospitals providing interventions had four or more interventional neuroradiologists.

CONCLUSIONS

Only a small number of hospitals in the United Kingdom provide interventional treatments for stroke. Almost 50% of hospitals not providing interventions had no processes in place for referral to providers.

Update on acute endovascular and surgical stroke treatment

Emergency stroke care has become a natural part of the emerging discipline of neurocritical care and demands close cooperation between the neurologist and neurointerventionists, neurosurgeons, and anesthesiologists. Endovascular treatment (EVT), including intra-arterial thrombolysis, mechanical thrombectomy and angioplasty/stenting, is under rapid development. Although EVT has yet to be shown in randomized controlled trials to improve clinical outcome compared to intravenous thrombolysis, it is far better in achieving recanalization of occluded large cerebral vessels, which is crucial for rescuing the penumbra. Moreover, decompressive craniectomy is now a well-established treatment option for malignant middle cerebral artery infarction and cerebellar stroke. Using a case-based approach, this article reviews recent achievements in advanced treatment options for patients with acute ischemic stroke.

Impact of telemedicine on acute management of stroke patients undergoing endovascular procedures

BACKGROUND

Telemedicine is improving acute stroke care in remote areas. Delay in hospital-to-hospital transfer is a common reason why acute ischemic stroke patients are excluded from interventional therapy. The progressive implementation of these procedures, requiring highly specialized professionals in comprehensive stroke centers, will certainly challenge even more the geographic equity in the access to the best acute stroke treatments. We aimed to assess the benefits of telemedicine in selecting stroke patients for endovascular treatments.

METHODS

In our Reference Comprehensive Stroke Center (RCSC), we perform urgent intra-arterial procedures in acute stroke patients. Patients may be primarily admitted (PA) or referred from community hospitals with (TMHs; 2 centers) or without telemedicine (nonTMHs; 7 centers). We prospectively studied all consecutive stroke patients undergoing urgent endovascular recanalization procedures in the RCSC. We studied different outcome measures according to the patients' initial admission: PA patients, TMH patients or nonTMH patients. For all patients, demographic and outcome data including serial National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores at 3 months were recorded. Clinical improvement was defined as a decrease ≥4 points on the NIHSS at 7 days or discharge and favorable outcome as mRS ≤2 at 3 months. Whether an endovascular procedure was indicated was decided according to clinical, radiological and transcranial Doppler (TCD) data, independently of the patient's initial admission center.

RESULTS

During a 2-year period, 119 patients received endovascular treatment: PA patients 74 (63.1%), TMH patients 25 (20.5%), nonTM patients 20 (16.4%). The mean distance to the RCSC was 52 ± 15 km for TMHs and 34.5 ± 12 km for nonTMHs (p = 0.4). There were no differences in baseline characteristics including age (71, 71.6 and 66.5 years; p = 0.25), baseline NIHSS (18.5, 19 and 18; p = 0.57) and previous use of intravenous tissue plasminogen activator (56.5, 56.5 and 57.9%; p = 0.95). The rate of recanalization (modified Thrombolysis in Cerebral Infarction Score ≥2a) was similar in all groups (75, 66.6 and 68.4%; p = 0.682). TMH and PA patients had similar clinical improvement (61 vs. 63.8%; p = 0.51) and good functional outcome (36.8 vs. 35.3%; p = 0.722). Conversely, nonTMH patients presented a lesser degree of clinical improvement (31.3%) and poorer functional outcome (15.8%) than TMH (p = 0.019 and p = 0.046) and PA patients (p = 0.05 and p = 0.013). TMH patients had significantly shorter door-to-groin puncture times (47 vs. 69 min; p = 0.047).

CONCLUSIONS

Telemedicine assessment to select patients for endovascular procedures improves the efficiency in stroke management and possibly the early and long-term outcome in patients receiving intra-arterial reperfusion treatment.

Intravenous alteplase versus rescue endovascular procedure in patients with proximal middle cerebral artery occlusion

OBJECTIVES

To compare outcome of ischaemic stroke patients undergoing rescue endovascular procedure for proximal middle cerebral artery occlusion with matched patients without endovascular procedure after unsuccessful intravenous thrombolysis.

METHODS

Endovascularly treated patients with middle cerebral artery occlusion (n = 41) were matched by propensity score with similar patients treated by intravenous thrombolysis and having a considerable post-thrombolysis neurological deficit (n = 82). We compared their three-month outcome (modified Rankin Scale) and frequency of symptomatic intracerebral haemorrhage. For the endovascular group, we report onset-to-puncture time, onset-to-recanalization time, and recanalization rates.

RESULTS

In age, gender, time from onset, admission National Institutes of Health Stroke Scale, systolic and diastolic blood pressure, blood glucose, history of hypertension, diabetes mellitus, hyperlipidaemia, atrial fibrillation, and congestive heart failure, and in aetiology, the groups were similar. Endovascular group patients had a recanalization rate of 90%, and more often reached three-month modified Rankin Scale 0-2 (36.6% vs. 18.3%, P = 0.03). Mortality was equally common (19.5%) in both groups, and frequency of symptomatic intracerebral haemorrhage was 9.8% vs. 14.6% (P = 0.45). The endovascular group's median onset-to-puncture time was four-hours and six-minutes and onset-to-recanalization time was five-hours and 12 min. The latter time was more than one-hour longer in patients treated under general anaesthesia compared with patients treated under conscious sedation (median four-hours 50 min vs. five-hours 58 min; P < 0.01).

CONCLUSIONS

Rescue endovascular approach increases likelihood of recanalization and may improve functional outcome in acute ischaemic stroke patients with proximal middle cerebral artery occlusion who did not respond to intravenous thrombolysis.

Developing practice recommendations for endovascular revascularization for acute ischemic stroke

Guidelines have been established for the management of acute ischemic stroke; however, specific recommendations for endovascular revascularization therapy are lacking. Burgeoning investigation of endovascular revascularization therapies for acute ischemic stroke, rapid device development, and a diverse training background of the providers performing the procedures underscore the need for practice recommendations. This review provides a concise summary of the Society of Vascular and Interventional Neurology endovascular acute ischemic stroke roundtable meeting. This document was developed to review current clinical efficacy of pharmacologic and mechanical revascularization therapy, selection criteria, periprocedure management, and endovascular time metrics and to highlight current practice patterns. It therefore provides an outline for the future development of multisociety guidelines and recommendations to improve patient selection, procedural management, and organizational strategies for revascularization therapies in acute ischemic stroke.

Treatment of acute ischemic stroke: systemic or local?

Systemic treatment of acute ischemic stroke currently means intravenous infusion of plasminogen activator in patients with the stroke syndrome after exclusion of brain hemorrhage irrespective of whether thrombotic arterial obstruction is present or not. In contrast, local intra-arterial treatment requires digital subtraction angiography and means direct treatment of the arterial pathology with the aim of recanalization and brain tissue reperfusion. Randomized controlled trials that test these two treatment approaches are missing. This paper discusses whether the time-saving systemic treatment approach is more promising for acute ischemic stroke patients than is the time-consuming endovascular local approach.

Bridging therapy in acute ischemic stroke: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Pending the results of randomized controlled trials, the benefit and safety of bridging therapy (combined intravenous and intra-arterial thrombolysis) remain to be determined. The aim of this analysis was to give reliable estimates of efficacy and safety outcomes of bridging therapy.

METHODS

We conducted a systematic review of all studies using bridging therapy published between January 1966 and March 2011.

RESULTS

The literature search identified 15 studies. The pooled estimate for recanalization rate was 69.6% (95% CI, 63.9%-75.0%). Meta-analysis on clinical outcomes showed a pooled estimate of 48.9% (95% CI, 42.9%-54.9%) for favorable outcome, 17.9% (95% CI, 12.7%-23.7%) for mortality, and 8.6% (95% CI, 6.8%-10.6%) for symptomatic intracranial hemorrhage. In meta-regression analysis, the shorter mean time to intravenous treatment, the greater the recanalization rate (per 10-minute decrease: OR, 1.24; 95% CI, 1.02-1.51) and the lower mortality rate (per 10-minute decrease: OR, 0.75; 95% CI, 0.60-0.94). By using the control groups of intravenous alteplase-treated patients in 8 studies, bridging therapy was associated with a favorable outcome (OR, 2.26; 95% CI, 1.16-4.40), but no differences in mortality or symptomatic intracranial hemorrhage outcomes were found.

CONCLUSIONS

Bridging therapy is associated with acceptable safety and efficacy in stroke patients. Time to intravenous treatment is critical to improve recanalization rates and favorable outcomes.

Evaluation of an intravenous-endovascular strategy in patients with acute proximal middle cerebral artery occlusion

BACKGROUND AND PURPOSE

IVT administered in acute ischemic stroke provides low recanalization rates in proximal intracranial occlusions, with consequently poor clinical outcome. The safety and efficacy of an IES by using mechanical thrombectomy after IVT failure were assessed in acute MCA occlusions.

MATERIALS AND METHODS

Patients presenting with acute MCA occlusion within 4.5 hours with an NIHSS score between 8 and 25 and a DWI ASPECTS of >5 were eligible. From September 2009 to September 2010, mechanical thrombectomy by using the Solitaire FR device was systematically performed if no clinical improvement was observed 1 hour after the initiation of IVT (IES group). Results in terms of clinical outcome were compared with those from an IVT series from January 2007 to August 2009 (IVT group).

RESULTS

Alteplase was administered in 123 patients with proximal intracranial occlusion. Fifty-six had a confirmed MCA occlusion: 32 were included in the IVT group; and 24, in the IES group. At 24 hours, the median NIHSS improvement was 8.5 points in the IES group (25%-75% CI, 1.5-13) and 3 points in the IVT group (25%-75% CI, 1-5) (P = .001). At 3 months, 17/22 (77%) patients from the IES group and 15/30 (50%) from the IVT group had an mRS score of ≤2. After adjustment for confounding variables, IES was strongly associated with favorable clinical outcome (77% versus 50%; adjusted odds ratio = 11.9; 95% CI, 1.6-89.1; P < .02). No symptomatic intracranial hemorrhage was observed.

CONCLUSIONS

IES by using systematic mechanical thrombectomy after IVT failure safely improves the clinical outcome at 3 months and could represent an interesting alternative in the management of patients with acute MCA occlusion.

Pharmacological revascularization of acute ischaemic stroke: focus on challenges and novel strategies

The only currently approved treatment for acute ischaemic stroke (AIS) is alteplase, a thrombolytic agent given intravenously (IV) within 4.5 hours of symptom onset, in an attempt to reopen occluded intracerebral arteries. However, no more than 5% of all AIS patients receive IV alteplase, mainly because of too long symptom-onset-to-hospital intervals. Moreover, this strategy is effective for less than half of the patients treated within the therapeutic window. Early recanalization is the most powerful prognostic factor, and novel drugs or therapeutic strategies are primarily aimed at improving alteplase efficacy to rapidly and safely reopen the occluded arteries. Because IV alteplase-resistant thrombi are those with the largest clot burden, responsible for the most devastating brain-tissue infarctions, development of novel approved AIS therapies is an urgent priority. At present, in the absence of controlled trials, no valid recommendations can be made. However, the most promising emerging strategy is a combination of standard or low-dose IV alteplase with an intra-arterial (IA) procedure, including additional endovascular thrombolytic and/or mechanical clot retrieval. Notably, results of open trials using the IA route had relatively disappointing clinical outcomes, despite remarkable arterial recanalization rates. Controlled trials are urgently needed to evaluate strategies including an IA route. In addition, logistic and cost constraints will likely limit their routine use, even in industrialized countries. Combining of another IV drug and IV alteplase is a far less studied option, although much easier to implement. Add-on IV drugs could be an antiplatelet glycoprotein (GP) IIb/IIIa receptor antagonist, a direct thrombin inhibitor or a second thrombolytic agent, e.g. tenecteplase. However, neuroimaging to measure the clot burden and infarction size will probably be necessary to predict IV alteplase failure and the subsequent use of these eventual additional therapies.

The mid-M1 segment of the middle cerebral artery is a cutoff clot location for good outcome in intravenous thrombolysis

BACKGROUND AND PURPOSE

We studied the impact of the location of the thrombus (internal carotid artery, proximal M1 segment, distal M1 segment, M2 segment, and M3 segment of the middle cerebral artery) in predicting the clinical outcome of patients treated with intravenous thrombolytic therapy (<3 h) in a retrospective cohort.

METHODS

Anterior circulation thrombus was detected with computed tomography angiography in 105 patients. Baseline clinical and radiological information was collected and entered into logistic regression analysis to predict favorable clinical outcome (3-month modified Rankin Scale from 0 to 2 was a primary outcome measure).

RESULTS

Three months after stroke, there was a significant increase in mortality (32% vs. 3%, P < 0.001) and functional dependency (82% vs. 29%, P < 0.001) in patients with internal carotid artery or proximal M1 segment of the middle cerebral artery thrombus compared to a more distal occlusion. In the regression analysis, after adjusting for National Institutes of Health Stroke Scale, age, sex, and onset-to-treatment time, the clot location was an independent predictor of good clinical outcome (P = 0.001) and exhibited dose-response type behavior when moving from a proximal vessel position to a more distal one. When the location was dichotomized, a cutoff between the proximal and the distal M1 segments best differentiated between good and poor clinical outcome (OR = 16.0, 95% CI 3.9-66.2).

CONCLUSIONS

The outcome of acute internal carotid artery or proximal M1 segment of the middle cerebral artery occlusion is generally poor even if treated with intravenous thrombolysis. Alternative revascularization strategies should be considered. Vascular imaging at the admission is required to guide this decision.

Predictors of Tissue-Type Plasminogen Activator Nonresponders According to Location of Vessel Occlusion

Background and Purpose—

Information on the clinical and hemodynamic profile of intravenous tissue-type plasminogen activator nonresponders, at different locations of arterial occlusion, may improve the selection of candidates for rescue reperfusion therapies. Therefore, we aim to investigate predictors of failing intravenous tissue-type plasminogen activator therapy according to occluded vessel and location of the clot.

Methods—

We prospectively evaluated consecutive patients with an acute ischemic stroke admitted within the first 6 hours of onset. Five hundred forty-eight patients with documented intracranial occlusion were included. Patients were categorized according to site of vessel occlusion into 4 distinct groups: proximal middle cerebral artery occlusion (n=251), distal middle cerebral artery occlusion (n=194), internal carotid artery bifurcation occlusion (n=61), and basilar artery occlusion (n=42). Recanalization was assessed on transcranial Doppler at 1 hour of tissue-type plasminogen activator bolus.

Results—

Among patients with proximal middle cerebral artery occlusion, the presence of severe extracranial internal carotid artery stenosis or occlusion (OR, 2.36; 95% CI, 1.15–4.84; P =0.02) and age >74 years (OR, 1.84; 95% CI, 1.02–3.31; P =0.04) independently predicted no recanalization. No independent predictors of no recanalization were identified in patients with distal middle cerebral artery occlusion. In patients with internal carotid artery bifurcation occlusion, a previous diagnosis of hypertension (OR, 12.77; 95% CI, 2.12–76.88; P =0.05), and absence of atrial fibrillation (OR, 8.15; 95% CI, 1.40–47.44; P =0.02) emerged as independent predictors of no recanalization. Similarly, among patients with basilar artery occlusion, absence of atrial fibrillation was as an independent predictor of no recanalization (OR, 7.50; 95% CI, 1.40–40.35; P =0.02).

Conclusions—

The use of relevant predictors of no recanalization and a rapid neurovascular evaluation may improve the selection of patients for more aggressive rescue strategies.