Randomized Trial of Intraarterial Infusion of Urokinase Within 6 Hours of Middle Cerebral Artery Stroke

Multimodal CT in Acute Stroke

PURPOSE OF REVIEW

Multimodal CT imaging (non-contrast CT, NCCT; CT angiography, CTA; and CT Perfusion, CTP) is central to acute ischemic stroke diagnosis and treatment. We reviewed the purpose and interpretation of each component of multimodal CT, as well as the evidence for use in routine care.

RECENT FINDINGS

Acute stroke thrombolysis can be administered immediately following NCCT in acute ischemic stroke patients assessed within 4.5 h of symptom onset. Definitive identification of a large vessel occlusion (LVO) requires vascular imaging, which is easily achieved with CTA. This is critical, as the standard of care for LVO within 6 h of onset is now endovascular thrombectomy (EVT). CTA source images can also be used to estimate the efficacy of collateral flow in LVO patients. The final component (CTP) permits a more accurate assessment of the extent of the ischemic penumbra. Complete multimodal CT, including objective penumbral measurement with CTP, has been used to extend the EVT window to 24 h. There is also randomized controlled trial evidence for extension of the IV thrombolysis window to 9 h with multimodal CT. Although there have been attempts to assess for responders to reperfusion strategies beyond 6 h ("late window") using collateral grades, the only evidence for treatment of this group of patients is based on selection using multimodal CT including CTP. The development of fully automated software providing quantitative ischemic penumbral and core volumes has facilitated the adoption of CTP and complete multimodal CT into routine clinical use. Multimodal CT is a powerful imaging algorithm that is central to current ischemic stroke patient care.

[Endovascular therapy for acute stroke-An important role of neurologists]

Previous randomized clinical trials have revealed significant benefit of the endovascular thrombectomy for the patients with acute ischemic stroke. In this short communication, I would like to introduce the history of endovascular treatment for acute ischemic stroke in Japan, and give a positive message to the neurologists who might contribute to the treatment for acute ischemic stroke.

Intraarterial Thrombolysis as Rescue Therapy for Large Vessel Occlusions

Background and Purpose—

Mechanical thrombectomy (MT) devices have led to improved reperfusion and clinical outcomes in acute ischemic stroke patients with emergent large vessel occlusions; however, less than one-third of patients achieve complete reperfusion. Use of intraarterial thrombolysis in the context of MT may provide an opportunity to enhance these results. Here, we evaluate the use of intraarterial rtPA (recombinant tissue-type plasminogen activator) as rescue therapy (RT) after failed MT in the North American Solitaire Stent-Retriever Acute Stroke registry.

Methods—

The North American Solitaire Stent-Retriever Acute Stroke registry recruited sites within North America to submit data on acute ischemic stroke patients treated with the Solitaire device. After restricting the population of 354 patients to use of RT and anterior emergent large vessel occlusions, we compared patients who were treated with and without intraarterial rtPA after failed MT.

Results—

A total of 37 and 44 patients was in the intraarterial rtPA RT and the no intraarterial rtPA RT groups, respectively. Revascularization success (modified Thrombolysis in Cerebral Infarction ≥2b) was achieved in more intraarterial rtPA RT patients (61.2% versus 46.6%; P =0.13) with faster times to recanalization (100±85 versus 164±235 minutes; P =0.36) but was not statistically significant. The rate of symptomatic intracranial hemorrhage (13.9% versus 6.8%; P =0.29) and mortality (42.9% versus 44.7%; P =0.87) were similar between the groups. Good functional outcome (modified Rankin Scale score of ≤2) was numerically higher in intraarterial rtPA patients (22.9% versus 18.4%; P =0.64). Further restriction of the RT population to M1 occlusions only and time of onset to groin puncture ≤8 hours, resulted in significantly higher successful revascularization rates in the intraarterial rtPA RT cohort (77.8% versus 38.9%; P =0.02).

Conclusions—

Intraarterial rtPA as RT demonstrated a similar safety and clinical outcome profile, with higher reperfusion rates achieved in patients with M1 occlusions. Prospective studies are needed to delineate the role of intraarterial thrombolysis in MT.

Local in situ fibrinolysis for recanalization of an occluded extracranial-intracranial bypass: Technical note

Extracranial-intracranial (EC-IC) bypass is a versatile technique to augment or preserve blood flow when treating cerebrovascular pathologies to prevent ischemic complications. Technical success and good patient outcomes rely on the successful establishment and maintenance of a patent bypass graft. Multiple modalities have been developed to confirm intraoperative graft patency. However, techniques and strategies to manage an occluded bypass are sparsely reported. The authors describe a novel technique for the in situ fibrinolysis utilizing recombinant tissue plasminogen activator (r-tPA) to recanalize an occluded EC-IC bypass following thrombus formation. This technique is feasible and effective in restoring long term EC-IC graft patency without requirement of additional vessel harvest or added ischemia time which may be tailored for use with other pharmacologic agents based on the acuity of an in-graft thrombosis.

Antithrombotic Effect of Oral Administration of Mozuku (Cladosiphon okamuranus, Brown Seaweed) Extract in Rat

Dysfunction of vascular endothelial cells causes the risk of thrombosis. Aim of this study is to evaluate the antithrombotic effect of Okinawa mozuku (brown seaweed, Cladosiphon okamuranus) extract by using cultured vascular endothelial cells and rat carotid arterial thrombosis model induced by ferric chloride (FeCl3). The cell line (TKM-33) established from human umbilical vein endothelial cells were cultured with or without Okinawa mozuku extract. After incubation for 24 h, the conditioned medium was collected to evaluate urokinase-type plasminogen activator (u-PA) activity. Next, rats were fed with water or water containing 5% of Okinawa mozuku extract for 8 wk. After 8 wk of treatments, the rats were provided for the carotid arterial thrombosis model, and fibrinolytic factor and coagulation factor in blood were measured. Okinawa mozuku extract significantly augmented u-PA activity in the conditioned medium. The decrease of carotid artery blood flow induced by 40% FeCl3 injury in rats fed with Okinawa mozuku extract was less than that in control rats. Thus, oral administration of Okinawa mozuku extract prevented thrombus formation in this model. Oral administration of Okinawa mozuku extract significantly increased u-PA activity in euglobulin fraction, compared with control group. On the other hand, platelet aggregation activity, activated partial thromboplastin time, and active PAI-1 level in plasma exhibited no significant differences between control and Okinawa mozuku groups. These results indicate that oral administration of Okinawa mozuku enhances fibrinolytic activity in plasma and prevents thrombus formation which is induced by injury of vascular endothelial cells.

Percutaneous vascular interventions versus intravenous thrombolytic treatment for acute ischaemic stroke

BACKGROUND

Most ischaemic strokes are caused by blockage of a cerebral artery by a thrombus. Intravenous administration of recombinant tissue plasminogen activator given within 4.5 hours is now standard treatment for this condition. Percutaneous vascular interventions use an intra-arterial, mechanical approach for thrombus disruption or removal (thrombectomy). Recent randomised trials indicate that percutaneous vascular interventions are superior to usual care (usual care usually included intravenous thrombolysis). However, intravenous thrombolysis was usually given in both arms of the trial and there was a lack of direct comparison of percutaneous vascular interventions with intravenous thrombolysis.

OBJECTIVES

To assess the effectiveness and safety of percutaneous vascular interventions compared with intravenous thrombolytic treatment for acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last search: August 2018). In addition, in September 2017, we searched the following electronic databases: CENTRAL, MEDLINE, Embase, and Science Citation Index; and Stroke Trials Registry, and US National Institutes of Health Ongoing Trials Register, ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that directly compared a percutaneous vascular intervention with intravenous thrombolytic treatment in people with acute ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors applied the inclusion criteria, extracted data, and assessed risk of bias. We obtained both published and unpublished data. We assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

We included four trials with 450 participants. Data on functional outcome and death at end of follow-up were available for 443 participants from three trials. Compared with intravenous thrombolytic therapy, percutaneous vascular intervention did not improve the proportion of participants with good functional outcome (modified Rankin Scale score 0 to 2, risk ratio (RR) 1.01, 95% confidence interval (CI) 0.82 to 1.25, P = 0.92). The quality of evidence was low (outcome assessment was blinded, but not the treating physician or participants). At the end of follow-up, there was a non-significant increase in the proportion of participants who died in the percutaneous vascular intervention group (RR 1.34, 95% CI 0.84 to 2.14, P = 0.21). The quality of evidence was low (wide confidence interval). There was no difference in the proportion of participants with symptomatic intracranial haemorrhages between the intervention and control groups (RR 0.99, 95% CI 0.50 to 1.95, P = 0.97). The quality of evidence was low (wide confidence interval). Data on vascular status (recanalisation rate) were only available for seven participants from one trial; we considered this inadequate for statistical analyses.

AUTHORS' CONCLUSIONS

The present review directly compared intravenous thrombolytic treatment with percutaneous vascular interventions for ischaemic stroke. We found no evidence from RCTs that percutaneous vascular interventions are superior to intravenous thrombolytic treatment with respect to functional outcome. Quality of evidence was low (outcome assessment was blinded, but not the treating physician or participants). New trials with adequate sample sizes are warranted because of the rapid development of new techniques and devices for such interventions.

The POST trial: initial post-market experience of the Penumbra system: revascularization of large vessel occlusion in acute ischemic stroke in the United States and Europe

Background and purpose

The purpose of this study was to assess the initial post-market experience of the device and how it is compared with the Penumbra Pivotal trial used to support the 510k application.

Methods

A retrospective case review of 157 consecutive patients treated with the Penumbra system at seven international centers was performed. Primary endpoints were revascularization of the target vessel (TIMI score of 2 or 3), good functional outcome as defined by a modified Rankin scale (mRS) score of ≤2 and incidence of procedural serious adverse events. Results were compared with those of the Penumbra pivotal trial.

Results

A total of 157 vessels were treated. Mean baseline values at enrollment were: age 65 years, NIHSS score 16. After use of the Penumbra system, 87% of the treated vessels were revascularized to TIMI 2 (54%) or 3 (33%) as compared with 82% reported in the Pivotal trial. Nine procedural serious adverse events were reported in 157 patients (5.7%). All-cause mortality was 20% (32/157), and 41% had a mRS of ≤2 at 90-day follow-up as compared with only 25% in the Pivotal trial. Patients who were successfully revascularized by the Penumbra system had significantly better outcomes than those who were not.

Conclusion

Initial post-market experience of the Penumbra system revealed that the revascularization rate and safety profile of the device are comparable to those reported in the Pivotal trial. However, the proportion of patients who had good functional outcome was higher than expected.

Emergency Neurological Life Support: Acute Ischemic Stroke

Acute ischemic stroke is a neurological emergency that can be treated with time-sensitive interventions, including both intravenous thrombolysis and endovascular approaches to thrombus removal. Extensive study has demonstrated that rapid, protocolized, assessment and treatment is essential to improving neurological outcome. For this reason, acute ischemic stroke was chosen as an emergency neurological life support protocol. The protocol focuses on the first hour of medical care following the acute onset of a neurological deficit.

Mechanical Thrombectomy: Emerging Technologies and Techniques

BACKGROUND

The treatment of acute ischemic stroke due to large vessel occlusion (LVO) has revolutionized in the last decade. We sought to compile the most relevant literature published about the evolution in treating this disabling and fatal disease.

METHODS

A literature review of recent studies describing early treatment options like intravenous tissue plasminogen activator to the latest mechanical thrombectomy (MT) techniques was performed. We described in a chronological order the evolution of LVO treatment.

RESULTS

Recanalization rates with newer techniques and MT devices approach a 90% of effectiveness. Timely interventions have also resulted in better clinical outcomes with approximately 50% of patient achieving functional independence at 90 days. At least 14 new third generation thrombectomy devices are currently being evaluated in in vitro and clinical studies.

CONCLUSIONS

The treatment of LVO with MT is feasible and safe. MT is standard of care in treating acute ischemic stroke due to LVO.

Indications for the Performance of Intracranial Endovascular Neurointerventional Procedures: A Scientific Statement From the American Heart Association

Intracranial endovascular interventions provide effective and minimally invasive treatment of a broad spectrum of diseases. This area of expertise has continued to gain both wider application and greater depth as new and better techniques are developed and as landmark clinical studies are performed to guide their use. Some of the greatest advances since the last American Heart Association scientific statement on this topic have been made in the treatment of ischemic stroke from large intracranial vessel occlusion, with more effective devices and large randomized clinical trials showing striking therapeutic benefit. The treatment of cerebral aneurysms has also seen substantial evolution, increasing the number of aneurysms that can be treated successfully with minimally invasive therapy. Endovascular therapies for such other diseases as arteriovenous malformations, dural arteriovenous fistulas, idiopathic intracranial hypertension, venous thrombosis, and neoplasms continue to improve. The purpose of the present document is to review current information on the efficacy and safety of procedures used for intracranial endovascular interventional treatment of cerebrovascular diseases and to summarize key aspects of best practice.

Posterior Circulation Occlusions May Be Associated with Distal Emboli During Thrombectomy : Factors for Distal Embolization and a Review of the Literature

Background

Distal embolization or movement of the thrombus to previously uninvolved vasculature are feared complications during stroke thrombectomy. We looked at associated factors in a consecutive series of patients who underwent thrombectomy with the same endovascular device.

Methods

We included all patients with acute ischemic stroke in the anterior or posterior circulation, who underwent thrombectomy with the same thrombectomy device for acute stroke from 2013 to 2016. Distal embolization was defined as any movement of the thrombus into a previously uninvolved portion of the cerebral vasculature or the presence of thrombotic material further downstream in the affected vessel, which occurred after the initial angiogram. We studied patient-related as well as technical factors to determine their association with distal emboli.

Results

In this study 167 consecutive acute stroke patients treated with the emboTrap® device (Cerenovus, Irvine, CA, USA) were included with a median National Institutes of Health Stroke Scale (NIHSS) of 15 (range 2–30) and mean age of 67 years (SD 13.1 years). Of the patients in our cohort 20 (11.9%) experienced distal emboli, with 2.3% into a new territory and 9.6% into a territory distal to the primary occlusion. On univariate analysis, age, intravenous tissue plasminogen activator (tPA), posterior circulation occlusions, and general anesthesia were associated with distal emboli. On multivariate analysis, only posterior circulation occlusions (odds ratio OR 4.506 95% confidence interval CI 1.483–13.692, p = 0.008) were significantly associated with distal emboli. Distal embolization was not significantly associated with worse functional outcomes at 3 months, increased mortality or increased bleeding risk.

Conclusion

Posterior circulation occlusions were significantly associated with distal emboli during thrombectomy, possibly due to the lack of flow arrest during such procedures. New techniques and devices should be developed to protect against embolic complications during posterior circulation stroke thrombectomy.

Brain computed tomography using iterative reconstruction to diagnose acute middle cerebral artery stroke: usefulness in combination of narrow window setting and thin slice reconstruction

PURPOSE

The purpose of this study is to determine whether iterative model reconstruction (IMR) optimized for brain CT could improve the detection of acute stroke in the setting of thin image slices and narrow window settings.

METHODS

We retrospectively reviewed 27 patients who presented acute middle cerebral artery (MCA) stroke. Images were reconstructed using filtered back projection (FBP; 1- and 5-mm slice thickness) and IMR (1 mm thickness), and contrast-to-noise ratios (CNRs) of infarcted and non-infarcted areas were compared. To analyze the performance of acute MCA stroke detection, we used receiver operating characteristic (ROC) curve techniques and compared 5-mm FBP with standard and narrow window settings, and 1-mm FBP and IMR with narrow window settings.

RESULTS

The CNR in 1-mm IMR (1.1 ± 1.0) was significantly higher than in 5- (0.8 ± 0.7) and 1-mm FBP (0.4 ± 0.4) (p < 0.001). Furthermore, the average area under the ROC curve was significantly higher with 1-mm IMR with narrow window settings (0.90, 95% CI: 0.86, 0.94) than it was with 5-mm FBP (0.78, 95% CI: 0.72, 0.83).

CONCLUSION

The combination of thin image slices and narrow window settings under IMR reconstruction provide better diagnostic performance for acute MCA stroke than conventional reconstruction methods.

Initial Attempt to Select Patients for Mechanical Thrombectomy Using Noncontrast Computed Tomography and Symptom-Based Criteria: Single-Center Experience

BACKGROUND

In the treatment of acute ischemic stroke (AIS), patients need to be selected for mechanical thrombectomy (MT) in the acute phase. Selection criteria vary, however, depending on the patient's situation. This study investigated the effectiveness of a noncontrast computed tomography and symptom-based protocol for selecting patients for MT.

METHODS

This retrospective study included 20 patients with AIS. The first 8 patients (earlier group) were screened by magnetic resonance imaging (MRI). Among the later 12 patients, MRI was deliberately skipped in 9, and major vessel occlusion was confirmed by digital subtraction angiography after meeting 4 criteria: 1) hospital arrival within 90 minutes from onset; 2) National Institutes of Health Stroke Scale score 9-25; 3) history or presence of atrial fibrillation; and 4) Alberta Stroke Program Early CT Score of 9-10. The clinical outcomes and time course were compared.

RESULTS

Among the later period group, 9 of 12 patients skipped MRI-based confirmation of large vessel occlusion. They underwent the direct angiography protocol, which had a 78% (7/9) positive predictive value for identifying large-vessel occlusion. In this group, National Institutes of Health Stroke Scale scores on the next day had significantly improved (median -8 points) compared with those at admission. Good functional outcome did not differ between the groups at 3 months.

CONCLUSIONS

Noncontrast computed tomography and symptom-based selection of MT to treat AIS can be useful for achieving better neurologic recovery in a subgroup of patients. This approach could broaden the use of MT.

2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations for clinicians caring for adult patients with acute arterial ischemic stroke in a single document. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 guidelines and subsequent updates.

METHODS

Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. The members of the writing group unanimously approved all recommendations except when relations with industry precluded members voting. Prerelease review of the draft guideline was performed by 4 expert peer reviewers and by the members of the Stroke Council's Scientific Statements Oversight Committee and Stroke Council Leadership Committee. These guidelines use the American College of Cardiology/American Heart Association 2015 Class of Recommendations and Levels of Evidence and the new American Heart Association guidelines format.

RESULTS

These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings.

CONCLUSIONS

These guidelines are based on the best evidence currently available. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

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.

Iterative Reconstruction Designed for Brain CT: A Correlative Study With Filtered Back Projection for the Diagnosis of Acute Ischemic Stroke

OBJECTIVES

The objective of this study is to evaluate the usefulness of iterative model reconstruction designed for brain computed tomography (CT) (IMR-Neuro) for the diagnosis of acute ischemic stroke.

METHODS

This retrospective study included 20 patients with acute middle cerebral artery infarction who have undergone brain CT and 20 nonstroke patients (control). We reconstructed axial images with filtered back projection (FBP) and IMR-Neuro (slice thickness, 1 and 5 mm). We compared the CT number of the infarcted area, the image noise, contrast, and the contrast to noise ratio of the infarcted and the noninfarcted areas between the different reconstruction methods. We compared the performance of 10 radiologists in the detection of parenchymal hypoattenuation between 2 techniques using the receiver operating characteristic (ROC) techniques with the jackknife method.

RESULTS

The image noise was significantly lower with IMR-Neuro [5 mm: 2.5 Hounsfield units (HU) ± 0.5, 1 mm: 3.9 HU ± 0.5] than with FBP (5 mm: 4.9 HU ± 0.5, 1 mm: 10.1 HU ± 1.4) (P < 0.01). The contrast to noise ratio was significantly greater with IMR-Neuro (5 mm: 2.6 ± 2.1, 1 mm: 1.6 ± 1.3) than with FBP (5 mm: 1.2 ± 1.0; 1 mm: 0.6 ± 0.5) (P < 0.01). The value of the average area under the receiver operating curve was significantly higher with IMR-Neuro than FBP (5 mm: 0.79 vs 0.74, P = 0.04; 1 mm: 0.76 vs 0.69, P = 0.04).

CONCLUSIONS

Compared with FBP, IMR-Neuro improves the image quality and the performance for the detection of parenchymal hypoattenuation with acute ischemic stroke.

Update on Neurocritical Care of Stroke

PURPOSE OF REVIEW

This review will highlight the recent advancements in acute ischemic stroke diagnosis and treatment, with special attention to new features and recommendations of stroke care in the neurocritical care unit.

RECENT FINDINGS

New studies suggest that pre-hospital treatment of stroke with mobile stroke units and telestroke technology may lead to earlier stroke therapy with intravenous tissue plasminogen activator (tPA), and recent studies show tPA can be given in previously contraindicated situations. More rapid automated CT perfusion and angiography may demonstrate a vascular penumbra for neuroendovascular intervention. Further, the greatest advance in acute stroke treatment since 2014 is the demonstration that neuroendovascular catheter-based thrombectomy with stent retrievers recanalizing intracranial large vessel occlusion (LVO) improves both recanalization and long-term outcomes in several trials. Hemorrhagic transformation and severe large infarct cerebral edema remain serious post-stroke challenges, with new guidelines describing who and when patients should get medical or surgical intervention. The adage "time is brain" directs the most evidence-based approach for rapid stroke diagnosis for tPA eligible and LVO recanalization using an orchestrated team approach. The neurocritical care unit is the appropriate location to optimize stroke outcomes for the most severely affected stroke patients.

Periprocedural heparin use in acute ischemic stroke endovascular therapy: the TREVO 2 trial

BACKGROUND

The use of periprocedural heparin has previously been reported to be safe and potentially beneficial during thrombectomy with older generation devices. We aimed to evaluate the safety and clinical outcomes of heparin use in the stent retriever era.

METHODS

A post hoc analysis of the TREVO 2 trial was performed comparing baseline characteristics and clinical outcomes between patients who received (HEP+) and those who did not receive periprocedural heparin (HEP-) while undergoing MERCI or TREVO clot retrieval.

RESULTS

Of 173 patients, 58 (34%) received periprocedural heparin including 40 who received one preprocedural bolus (median 3000 units). Baseline characteristics among HEP+ and HEP- patients were similar except HEP+ patients had a lower NIH Stroke Scale (NIHSS) score (17 vs 19; p=0.04), lower IV tissue plasminogen activator use (38% vs 64%; p<0.01), and a higher median ASPECTS score (8.0 vs 7.0; p=0.02). HEP+ patients were more likely to have vertebrobasilar and middle cerebral artery (MCA)-M1 occlusions but less likely to have internal carotid artery and MCA-M2 occlusions (p=0.04). Time from symptom onset to puncture was similar in the two groups while procedure duration was longer in HEP+ patients (99 vs 83 min; p<0.01). Thrombolysis In Cerebral Infarction (TICI) 2b-3 reperfusion rates, embolization to unaffected territories, access site complications, and intracranial hemorrhages were similar between the groups. In multivariable logistic regression, a good outcome (90-day modified Rankin Scale score 0-2) was independently associated with heparin bolus use (OR 5.30; 95% CI 1.70 to 16.48), TICI 2b-3 reperfusion (OR 6.56; 95% CI 2.29 to 18.83), stent retriever use (OR 3.54; 95% CI 1.38 to 9.03) and inversely associated with intubation (OR 0.10; 95% CI 0.03 to 0.33), diabetes (OR 0.11; 95% CI 0.03 to 0.39), NIHSS (OR 0.84; 95% CI 0.75 to 0.93), time from symptom onset to puncture (OR 0.64; 95% CI 0.45 to 0.89), and heart failure (OR 0.23; 95% CI 0.06 to 0.83).

CONCLUSIONS

The use of periprocedural heparin in stent retriever thrombectomy is associated with a good clinical outcome at 90 days and similar rates of symptomatic intracranial hemorrhage. Further studies are warranted.

CLINICAL TRIAL REGISTRATION

URL:http://www.clinicaltrials.gov. Unique identifier: NCT01270867;Post-results.

In vivo evaluation of urokinase-loaded hollow nanogels for sonothrombolysis on suture embolization-induced acute ischemic stroke rat model

The urokinase-type plasminogen activator (uPA) loaded hollow nanogels (nUK) were synthesized by a one-step reaction of glycol chitosan and aldehyde capped poly (ethylene oxide). The resultant formulation is sensitive to diagnostic ultrasound (US) of 2 MHz. Herein, we evaluated the in vivo sonothrombolysis performance of the nUK on acute ischemic stroke rat model which was established by suture embolization of middle cerebral artery (MCA). Via intravenous (i.v.) administration, the experimental data prove a controlled release of the therapeutic protein around the clots under ultrasound stimulation, leading to enhanced thrombolysis efficiency of the nUK, evidenced from smaller infarct volume and better clinical scores when compared to the i.v. dose of free uPA no matter with or without US intervention. Meanwhile, the preservation ability of the nanogels not only prolonged the circulation duration of the protein, but also resulted in the better blood-brain barrier protection of the nUK formulation, showing no increased risk on the hemorrhagic transformation than the controls. This work suggests that the nUK is a safe sonothrombolytic formulation for the treatment of acute ischemic stroke.

•

Ultrasonic responsive urokinase (uPA)-loaded hollow nanogels (nUK) were synthesized for stroke treatment.

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Acute ischemic stroke rat model was established by suture embolization of middle cerebral artery.

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The nUK enhanced the sonothrombolytic efficacy and led to better BBB protection compared to the free uPA.

Application of emerging technologies to improve access to ischemic stroke care

During the past 20 years, the traditional supportive treatment for stroke has been radically transformed by advances in catheter technologies and a cohort of prominent randomized controlled trials that unequivocally demonstrated significant improvement in stroke outcomes with timely endovascular intervention. However, substantial limitations to treatment remain, among the most important being timely access to care. Nonetheless, stroke care has continued its evolution by incorporating technological advances from various fields that can further reduce patients' morbidity and mortality. In this paper the authors discuss the importance of emerging technologies—mobile stroke treatment units, telemedicine, and robotically assisted angiography—as future tools for expanding access to the diagnosis and treatment of acute ischemic stroke.

Imaging in Endovascular Stroke Trials

Ischemic stroke remains a leading cause of death and disability worldwide. Various endovascular trials have addressed clinical outcomes without elucidating the impact of imaging studies in patient selection. The success of recent endovascular trials was bolstered by the use of advanced imaging techniques for optimal selection of reperfusion candidates. This seminal juncture in the history of stroke trials warrants further consideration on the use of imaging to guide future refinements in the treatment of acute stroke. In this article, we systematically review the imaging methodology and key facets used in all published endovascular stroke trials to date, discuss the success of recent trials using latest advanced imaging techniques and focus on the importance of imaging studies for future patient selection.

Plasmin (Human) Administration in Acute Middle Cerebral Artery Ischemic Stroke: Phase 1/2a, Open-Label, Dose-Escalation, Safety Study

BACKGROUND

This phase 1/2a, open-label, multicenter, dose-escalation, safety study describes the first evaluation of plasmin as an intracranial thrombolytic treatment for acute ischemic stroke in the middle cerebral artery. The rationale for intrathrombus administration is that plasmin would bind fibrin inside the targeted clot, protecting it from circulating inhibitors.

METHODS

Plasmin was given in escalating doses within 9 hours of stroke onset, and treatment efficacy was determined in 5 patient cohorts (N = 40): cohort 1 (20 mg, .5 mL/min), cohort 2a (40 mg, .05 mL/min), cohort 2b (40 mg, .33 mL/min), cohort 3a (80 mg, .67 mL/min), and cohort 3b (80 mg, .33 mL/min).

RESULTS

Plasmin was generally safe at doses as high as 80 mg. No symptomatic intracranial hemorrhage was observed, and the rate of asymptomatic intracranial hemorrhage (12.5%) was consistent with that expected under supportive care. No relationship was observed between the plasmin dose and the incidence or severity of bleeding events, any particular serious adverse events, nor death. Changes in clinical chemistry, hematology, and coagulation parameters following plasmin treatment were unremarkable and unrelated to the dose. Plasmin administration resulted in successful reperfusion of the occluded vessel in 25% of patients across all cohorts, with no relationship between successful perfusion and total plasmin dose but a potential increase in reperfusion with slower infusion rates.

CONCLUSIONS

Plasmin treatment of the occluded middle cerebral artery within 9 hours of stroke onset was well tolerated and did notincrease adverse outcomes; however, successful recanalization was achieved in only a limited number of patients.

Endovascular Therapy of M2 Occlusion in IMS III: Role of M2 Segment Definition and Location on Clinical and Revascularization Outcomes

BACKGROUND AND PURPOSE

Uncertainty persists regarding the safety and efficacy of endovascular therapy of M2 occlusions following IV tPA. We reviewed the impact of revascularization on clinical outcomes in 83 patients with M2 occlusions in the Interventional Management of Stroke III trial according to specific M1-M2 segment anatomic features.

MATERIALS AND METHODS

Perfusion of any M2 branch distinguished M2-versus-M1 occlusion. Prespecified modified TICI and arterial occlusive lesion revascularization and clinical mRS 0-2 end points at 90 days for endovascular therapy-treated M2 occlusions were analyzed. Post hoc analyses of the relationship of outcomes to multiple baseline angiographic M2 and M1 subgroup characteristics were performed.

RESULTS

Of 83 participants with M2 occlusion who underwent endovascular therapy, 41.0% achieved mRS 0-2 at 90 days, including 46.6% with modified TICI 2-3 reperfusion compared with 26.1% with modified TICI 0-1 reperfusion (risk difference, 20.6%; 95% CI, -1.4%-42.5%). mRS 0-2 outcome was associated with reperfusion for M2 trunk (n = 9) or M2 division (n = 42) occlusions, but not for M2 branch occlusions (n = 28). Of participants with trunk and division occlusions, 63.2% with modified TICI 2a and 42.9% with modified TICI 2b reperfusion achieved mRS 0-2 outcomes; mRS 0-2 outcomes for M2 trunk occlusions (33%) did not differ from distal (38.2%) and proximal (26.9%) M1 occlusions.

CONCLUSIONS

mRS 0-2 at 90 days was dependent on reperfusion for M2 trunk but not for M2 branch occlusions. For M2 division occlusions, good outcome with modified TICI 2b reperfusion did not differ from that in modified TICI 2a. M2 segment definition and occlusion location may contribute to differences in revascularization and good outcome between Interventional Management of Stroke III and other endovascular therapy studies.

Citation bias favoring positive clinical trials of thrombolytics for acute ischemic stroke: a cross-sectional analysis

Background

Citation bias occurs when positive trials involving a medical intervention receive more citations than neutral or negative trials of similar quality. Several large clinical trials have studied the use of thrombolytic agents for the treatment of acute ischemic stroke with differing results, thereby presenting an opportunity to assess these trials for evidence of citation bias. We compared citation rates among positive, neutral, and negative trials of alteplase (tPA) and other thrombolytic agents for stroke.

Methods

We used a 2014 Cochrane Review of thrombolytic therapy for the treatment of acute stroke to identify non-pilot, English-language stroke trials published in MEDLINE-indexed journals comparing thrombolytic therapy with control. We classified trials as positive if there was a statistically significant primary outcome difference favoring the intervention, neutral if there was no difference in primary outcome, or negative for a significant primary outcome difference favoring the control group. Trials were also considered negative if safety concerns supported stopping the trial early. Using Scopus, we collected citation counts through 2015 and compared citation rates according to trial outcomes.

Results

Eight tPA trials met inclusion criteria: two were positive, four were neutral, and two were negative. The two positive trials received 9080 total citations, the four neutral trials received 4847 citations, and the two negative trials received 1096 citations. The mean annual per-trial citation rates were 333 citations per year for positive trials, 96 citations per year for neutral trials, and 35 citations per year for negative trials. Trials involving other thrombolytic agents were not cited as often, though as with tPA, positive trials were cited more frequently than neutral or negative trials.

Conclusions

Positive trials of tPA for ischemic stroke are cited approximately three times as often as neutral trials, and nearly 10 times as often as negative trials, indicating the presence of substantial citation bias.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1595-7) contains supplementary material, which is available to authorized users.

History, Evolution, and Importance of Emergency Endovascular Treatment of Acute Ischemic Stroke

More than 800,000 people in North America suffer a stroke each year, with ischemic stroke making up the majority of these cases. The outcomes of ischemic stroke range from complete functional and cognitive recovery to severe disability and death; outcome is strongly associated with timely reperfusion treatment. Historically, ischemic stroke has been treated with intravenous thrombolytic agents with moderate success. However, five recently published positive trials have established the efficacy of endovascular treatment in acute ischemic stroke. In this review, we will discuss the history of stroke treatments moving from various intravenous thrombolytic drugs to intra-arterial thrombolysis, early mechanical thrombectomy devices, and finally modern endovascular devices. Early endovascular therapy failures, recent successes, and implications for current ischemic stroke management and future research directions are discussed.

Acute Ischemic Stroke Involving Both Anterior and Posterior Circulation Treated by Endovascular Revascularization for Acute Basilar Artery Occlusion via Persistent Primitive Trigeminal Artery

We report a case of acute ischemic stroke involving both the anterior and posterior circulation associated with a persistent primitive trigeminal artery (PPTA), treated by endovascular revascularization for acute basilar artery (BA) occlusion via the PPTA. An otherwise healthy 67-year-old man experienced sudden loss of consciousness and quadriplegia. Magnetic resonance imaging showed an extensive acute infarction in the right cerebral hemisphere, and magnetic resonance angiography showed occlusion of the right middle cerebral artery (MCA) and BA. Because the volume of infarction in the territory of the right MCA was extensive, we judged the use of intravenous tissue plasminogen activator to be contraindicated. Cerebral angiography revealed hypoplasia of both vertebral arteries and the presence of a PPTA from the right internal carotid artery. A microcatheter was introduced into the BA via the PPTA and revascularization was successfully performed using a Merci Retriever with adjuvant low-dose intraarterial urokinase. After treatment, his consciousness level and right motor weakness improved. Although persistent carotid-vertebrobasilar anastomoses such as a PPTA are relatively rare vascular anomalies, if the persistent primitive artery is present, it can be an access route for mechanical thrombectomy for acute ischemic stroke.

Safety and Efficacy of Mechanical Thrombectomy in Acute Ischemic Stroke of Anticoagulated Patients-A Prospective Observational Study

BACKGROUND

Anticoagulated patients (APs) are excluded from the acute stroke management with alteplase in Europe, not in the United States. They could benefit from mechanical thrombectomy (MT), which was not undoubtedly proven. There are scarce data about its results in such patients. The authors' aim is to analyze the efficacy and safety of MT in APs presenting with an acute stroke in our institution.

METHODS

Prospective observational study comparing 30 APs and 109 non-anticoagulated patients (N-APs) underwent direct MT without alteplase. Demographic data, clinical severity (National Institutes of Health Stroke Scale [NIHSS]), efficacy (recanalization thrombolysis in cerebral infarction [TICI] ≥ 2b and modified Rankin Scale score ≤ 2 at 3 months), and security (symptomatic intracranial hemorrhage [SICH], mortality at 3 months) were compared between both groups.

RESULTS

In both groups men were more frequent (63.3% of APs were men and 61.5% of N-APs were men). Mean age was 73 in APs and 67.2 in N-APs. Median NIHSS was similar (17 APs; 16 N-APs), also TICI greater than or equal to 2b (93.3% APs; 89.9% N-APs). The 3-month modified Rankin Scale score less than or equal to 2 was 46.7% in APs and 55.2% in N-APs (P = .40). SICH was present in 16.7% of APs and 8.3% of N-APs (P = .15). Mortality at 3 months was 6.7% in APs and 19% in N-APs (P = .08).

CONCLUSIONS

MT is a valid treatment option in APs. It achieves an efficacy as in N-APs with a tendency to suffer more from SICH, but lower mortality. We hypothesize that cardioembolic clots may be easier to be removed than atherotrombotics, and that embolic stroke in APs might be less severe than that in N-APs or might suffer less of other complications than atherotrombotics.

A Comparison between Mechanical Thrombectomy and Intra-arterial Fibrinolysis in Acute Basilar Artery Occlusion: Single Center Experiences

Background and Purpose

Recent advances in intra-arterial techniques and thrombectomy devices lead to high rate of recanalization. However, little is known regarding the effect of the evolvement of endovascular revascularization therapy (ERT) in acute basilar artery occlusion (BAO). We compared the outcome of endovascular mechanical thrombectomy (EMT) versus intra-arterial fibrinolysis (IAF)-based ERT in patients with acute BAO.

Methods

After retrospectively reviewed a registry of consecutive patients with acute ischemic stroke who underwent ERT from September 2003 to February 2015, 57 patients with acute BAO within 12 hours from stroke onset were enrolled. They were categorized as an IAF group (n=24) and EMT group (n=33) according to the primary technical option. We compared the procedural and clinical outcomes between the groups.

Results

The time from groin puncture to recanalization was significantly shorter in the EMT group than in the IAF group (48.5 [25.3 to 87.8] vs. 92 [44 to 179] minutes; P=0.02) The rate of complete recanalization was significantly higher in the EMT group than in the IAF group (87.9% vs 41.7%; P<0.01). The good outcome of the modified Rankin Scale score≤2 at 3 months was more frequent in the EMT group than in the IAF group, but it was not statistically significant (39.4% vs 16.7%; P=0.06).

Conclusions

EMT-based ERT in patients with acute BAO is superior to IAF-based ERT in terms of the reduction of time from groin puncture to recanalization and the improvement of the rate of complete recanalization.

Endovascular Treatment versus Best Medical Treatment in Patients with Acute Ischemic Stroke: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND PURPOSE

Endovascular treatment has emerged as a minimally invasive technique for patients with acute ischemic stroke to achieve recanalization. Our aim was to determine the effects of endovascular treatment on clinical and safety outcomes compared with best medical treatment.

MATERIALS AND METHODS

Fifteen randomized trials that compared endovascular treatment with best medical treatment in patients with acute ischemic stroke met the inclusion criteria. We calculated pooled odds ratios and 95% CIs by using random-effects models. The primary end point was a favorable outcome defined by a modified Rankin Scale score of 0 (no symptoms), 1 (no significant disability), or 2 (slight disability) at 90 days postrandomization.

RESULTS

Of the 2980 subjects randomized, the proportion of subjects who achieved a favorable outcome was significantly greater among those randomized to endovascular treatment compared with best medical treatment (2949 subjects analyzed; odds ratio, 1.82; 95% CI, 1.38-2.40; P < .001). Excellent outcome (modified Rankin Scale score of 0 or 1) was also significantly greater among those randomized to endovascular treatment (2791 subjects analyzed; odds ratio, 1.77; 95% CI, 1.29-2.43, P < .001). Risk of symptomatic intracranial hemorrhage was similar between endovascular treatment and best medical treatment (2906 subjects analyzed; odds ratio, 1.19; 95% CI, 0.84-1.68; P = .34).

CONCLUSIONS

Compared with best medical treatment, the odds of achieving a favorable outcome or excellent outcome at 3 months postrandomization are approximately 80% higher with endovascular treatment among patients with acute ischemic stroke.

Evolving Treatments for Acute Ischemic Stroke

The purpose of this article is to review advances in stroke treatment in the hyperacute period. With recent evolutions of technology in the fields of imaging, thrombectomy devices, and emergency room workflow management, as well as improvement in statistical methods and study design, there have been ground breaking changes in the treatment of acute ischemic stroke. We describe how stroke presents as a clinical syndrome and how imaging as the most important biomarker will help differentiate between stroke subtypes and treatment eligibility. The evolution of hyperacute treatment has led to the current standard of care: intravenous thrombolysis with tissue-type plasminogen activator and endovascular treatment for proximal vessel occlusion in the anterior cerebral circulation. All patients with acute ischemic stroke are in need of hyperacute secondary prevention because the risk of recurrence is highest closest to the index event. The dominant themes of modern stroke care are the use of neurovascular imaging and speed of diagnosis and treatment.

Primary acute stroke thrombectomy within 3 h for large artery occlusion (PAST3-LAO): a pilot study

BACKGROUND AND PURPOSE

In recent trials, acute ischemic stroke (AIS) from large artery occlusion (LAO) was resistant to intravenous thrombolysis and adjunctive stent retriever thrombectomy (SRT) was associated with better perfusion and outcomes. Despite benefit, 39-68% of patients had poor outcomes. Thrombectomy in AIS with LAO within 3 h is performed secondary to intravenous thrombolysis, which may be associated with delay. The purpose of our study is to evaluate the safety, feasibility, recanalization rate, and outcome of primary SRT within 3 h without intravenous thrombolysis in AIS from LAO.

METHODS

Based on an institutionally approved protocol, stroke patients with LAO within 3 h were offered primary SRT as an alternative to intravenous recombinant tissue plasminogen activator. Consecutive patients who underwent primary SRT for LAO within 3 h from 2012 to 2014 were enrolled. Outcomes were measured using the modified Rankin Scale (mRS).

RESULTS

18 patients with LAO of mean age 62.83±15.32 years and median NIH Stroke Scale (NIHSS) score 16 (10-23) chose primary SRT after giving informed consent. Near complete (TICI 2b in 1 patient) or complete (TICI 3 in 17 patients) recanalization was observed in all patients. Time to recanalization from symptom onset and groin puncture was 188.5±82.7 and 64.61±40.14 min, respectively. NIHSS scores immediately after thrombectomy, at 24 h and 30 days were 4 (0-12), 1 (0-12), and 0 (0-4), respectively. Asymptomatic perfusion-related hemorrhage developed in four patients (22%). 90-day outcomes were mRS 0 in 50%, mRS 1 in 44.4%, and mRS 2 in 5.6%.

CONCLUSIONS

Our study demonstrates that primary SRT in AIS from LAO is safe and feasible and is associated with complete recanalization and good outcome. Further study is required.

Homogeneity and the outcome of clinical trials: An appraisal of the outcome of recent clinical trials on endovascular intervention in acute ischemic stroke

Clinical trials that allow significant heterogeneity of population or interventions often result in uncertain outcomes. In this paper, we review the outcomes of five recent trials of endovascular interventions in acute ischemic stroke in the context of the neutral results of previous large clinical trials on the subject.

Endovascular therapy including thrombectomy for acute ischemic stroke: A systematic review and meta-analysis with trial sequential analysis

One of the primary strategies for the management of acute ischemic stroke is intravenous (IV) thrombolysis with tissue plasminogen activator (t-PA). Over the past decade, endovascular therapies such as the use of stent retrievers to perform mechanical thrombectomy have been found to improve functional outcomes compared to t-PA alone. We aimed to reassess the functional outcomes and complications of IV thrombolysis with and without endovascular treatment for acute ischemic stroke using conventional meta-analysis and trial sequential analysis. Pooled relative risks (RR) and 95% confidence intervals (CI) were calculated for the effect of IV thrombolysis with and without endovascular therapy on functional outcome, mortality and symptomatic intracranial hemorrhage (SICH). Trial sequential analysis was done to strengthen the meta-analysis. We analyzed six randomized controlled trials involving 1943 patients. Patients who received IV thrombolysis with endovascular treatment showed significantly higher rates of excellent functional outcomes (modified Rankin Scale [mRS] 0-1) (RR, 1.75 [95% CI, 1.29-2.39]) compared to those who received IV thrombolysis alone. A similar association was seen for good functional outcomes (mRS 0-2) (RR, 1.56 [95% CI, 1.24-1.96]). Trial sequential analysis demonstrated endovascular treatment increased the RR of a good functional outcome by at least 30% compared to IV thrombolysis alone. There was no significant difference in all-cause mortality for mechanical thrombectomy compared to IV thrombolysis alone or the incidence of SICH at 3month follow-up. Endovascular treatment is more likely to result in a better functional outcome for patients compared to IV thrombolysis alone for acute ischemic stroke.

Routine Head Computed Tomography for Patients in the Emergency Room with Trauma Requires Both Thick- and Thin-Slice Images

Background. Images of head CT for the supratentorial compartment are sometimes recommended to be reconstructed with a thickness of 8–10 mm to achieve lesion conspicuity. However, additional images of a thin slice may not be routinely provided for patients with trauma in the emergency room (ER). We investigated the diagnostic sensitivity of a head CT, where axial images were 10 mm thick slices, in cases of linear skull fractures. Methods. Two trauma surgeons retrospectively reviewed head CT with 10 mm slices and skull X-rays of patients admitted to the ER that were diagnosed with a linear skull fracture. All patients had undergone both head CT and skull X-rays (n = 410). Result. The diagnostic sensitivity of head CT with a thickness of sequential 10 mm was 89% for all linear skull fractures but only 56% for horizontal fractures. This CT technique with 10 mm slices missed 6% of patients with linear skull fractures. False-negative diagnoses were significantly more frequent for older (≥55 years) than for young (<15 years) individuals (p = 0.048). Conclusions. A routine head CT of the supratentorial region for patients in the ER with head injuries requires both thick-slice images to visualize cerebral hemispheres and thin-slice images to detect skull fractures of the cranial vault.

Endovascular Treatment Versus Intravenous Thrombolysis for Acute Ischemic Stroke: a Quantitative Review and Meta-Analysis of 21 Randomized Trials

Emerging studies suggest that endovascular treatment (EVT) may be superior to intravenous thrombolysis for acute ischemic stroke (AIS). We performed a systematic review and meta-analysis of all randomized controlled trials (RCTs) to assess the efficacy and safety of endovascular treatment in patients with acute ischemic stroke as compared with intravenous thrombolysis. We assessed RCTs investigating EVT versus intravenous thrombolysis (IVT) published up to June 2015. In total, 21 studies of 4473 patients were included in the systematic review and meta-analysis. EVT significantly improved functional outcome at 90 days (risk ratio (RR) 1.35, 95 % confidence interval (CI) 1.18 to 1.55, I ² = 61 %) and reduced the mortality (RR 0.81, 95 % CI 0.68 to 0.95, I ² = 0 %), with similar symptomatic hemorrhagic transformation (SHT) rate (RR 1.12, 95 % CI 0.88 to 1.44, I ² = 0 %). Based on the current data, endovascular therapy may produce good clinical outcomes with similar symptomatic hemorrhage and mortality as compared with intravenous thrombolysis in acute ischemic stroke. This advancing intervention is a landmark change in stroke treatment and could be of huge potential benefit to patients worldwide.

Meta-Analysis of Local Endovascular Therapy for Acute Ischemic Stroke

A meta-analysis was performed to assess randomized controlled trials comparing local endovascular therapy (with and without intravenous thrombolysis) versus standard care (intravenous thrombolysis alone when appropriate) for acute ischemic stroke. Local endovascular therapy showed a significant improvement in functional independence versus standard care (odds ratio, 1.779; 95% confidence interval, 1.262-2.507; P < .001). This benefit strengthened further on subgroup analyses of trials in which a majority of cases used stent retrievers, trials with intravenous thrombolysis use in both arms when appropriate, and trials that required preprocedural imaging of all patients. There were no significant differences between arms in terms of mortality, hemicraniectomy, intracranial hemorrhage, and cerebral edema rates (P > .05). In conclusion, in the treatment of acute ischemic stroke, local endovascular therapy leads to improved functional independence compared with standard care.

Does the use of IV tPA in the current era of rapid and predictable recanalization by mechanical embolectomy represent good value?

As healthcare delivery in the USA transforms into a model that at its core requires value-based considerations, ischemic stroke is confronted by intersecting forces. Modern techniques allow rapid revascularization in the majority of patients with large vessel occlusions. Dramatic advances in the evidentiary basis for mechanical embolectomy are increasing the number of patients treated with this therapy. A key part of the therapeutic arsenal in many patients treated with interventional techniques has been concurrent intravenous thrombolysis. We consider whether this paradigm warrants change.