A trial of imaging selection and endovascular treatment for ischemic stroke

[Education for stroke neurologists in neuroendovascular revascularization therapy of acute ischemic stroke]

Outcome of large cerebral artery occlusions in intravenous recombinant tissue plasminogen activator failed and ineligible patients has been improved by Mechanical clot retrievers. The key words of revascularization therapies are improvement of reperfusion rate and shortening of reperfusion time. Stroke neurologists have to acquire skill of neuroendovascular therapy technique, because acute stroke patients are examined first by stroke neurologists. However acquisition of neuroendovascular skills are not easy for stroke neurologists. It is important that we establish the educational systems of neuroendovascular therapy for stroke neurologists.

Design and Validation of a Prehospital Stroke Scale to Predict Large Arterial Occlusion

Background and Purpose—

We aimed to develop and validate a simple prehospital stroke scale to predict the presence of large vessel occlusion (LVO) in patients with acute stroke.

Methods—

The Rapid Arterial oCclusion Evaluation (RACE) scale was designed based on the National Institutes of Health Stroke Scale (NIHSS) items with a higher predictive value of LVO on a retrospective cohort of 654 patients with acute ischemic stroke: facial palsy (scored 0–2), arm motor function (0–2), leg motor function (0–2), gaze (0–1), and aphasia or agnosia (0–2). Thereafter, the RACE scale was validated prospectively in the field by trained medical emergency technicians in 357 consecutive patients transferred by Emergency Medical Services to our Comprehensive Stroke Center. Neurologists evaluated stroke severity at admission and LVO was diagnosed by transcranial duplex, computed tomography, or MR angiography. Receiver operating curve, sensitivity, specificity, and global accuracy of the RACE scale were analyzed to evaluate its predictive value for LVO.

Results—

In the prospective cohort, the RACE scale showed a strong correlation with NIHSS ( r =0.76; P <0.001). LVO was detected in 76 of 357 patients (21%). Receiver operating curves showed a similar capacity to predict LVO of the RACE scale compared with the NIHSS (area under the curve 0.82 and 0.85, respectively). A RACE scale ≥5 had sensitivity 0.85, specificity 0.68, positive predictive value 0.42, and negative predictive value 0.94 for detecting LVO.

Conclusions—

The RACE scale is a simple tool that can accurately assess stroke severity and identify patients with acute stroke with large artery occlusion at prehospital setting by medical emergency technicians.

Relative Cerebral Blood Volume as a Marker of Durable Tissue-at-Risk Viability in Hyperacute Ischemic Stroke

Background and Purpose—

Selection of best responders to reperfusion therapies could be aided by predicting the duration of tissue-at-risk viability, which may be dependant on collateral circulation status. We aimed to identify the best predictor of good collateral circulation among perfusion computed tomography (PCT) parameters in middle cerebral artery (MCA) ischemic stroke and to analyze how early MCA response to intravenous thrombolysis and PCT-derived markers of good collaterals interact to determine stroke outcome.

Methods—

We prospectively studied patients with acute MCA ischemic stroke treated with intravenous thrombolysis who underwent PCT before treatment showing a target mismatch profile. Collateral status was assessed using a PCT source image–based score. PCT maps were quantitatively analyzed. Cerebral blood volume (CBV), cerebral blood flow, and Tmax were calculated within the hypoperfused volume and in the equivalent region of unaffected hemisphere. Occluded MCAs were monitored by transcranial Duplex to assess early recanalization. Main outcome variables were brain hypodensity volume and modified Rankin scale score at day 90.

Results—

One hundred patients with MCA ischemic stroke imaged by PCT received intravenous thrombolysis, and 68 met all inclusion criteria. A relative CBV (rCBV) >0.93 emerged as the only predictor of good collaterals (odds ratio, 12.6; 95% confidence interval, 2.9–55.9; P =0.001). Early MCA recanalization was associated with better long-term outcome and lower infarct volume in patients with rCBV<0.93, but not in patients with high rCBV. None of the patients with rCBV<0.93 achieved good outcome in absence of early recanalization.

Conclusions—

High rCBV was the strongest marker of good collaterals and may characterize durable tissue-at-risk viability in hyperacute MCA ischemic stroke.

Editorial: Workforce needs for endovascular acute ischemic stroke therapy: myth or reality?

The acute ischemic strokes amenable to intraarterial therapy probably number no more than 20,000 per year in the United States. The future demand for intraarterial reperfusion techniques may change, but the fraction of patients who require intraarterial thrombolysis is currently rather low, and the number of neurointerventionists is adequate. Each hospital caring for patients with acute stroke will need to determine its own demand for intraarterial therapy and employ an adequate supply of qualified neurointerventionists available to meet demand. Comprehensive stroke centers are now being designated and hopefully will foster a rational, regionalized approach to the delivery of endovascular therapies for stroke.

Comparative efficacy of different acute reperfusion therapies for acute ischemic stroke: a comprehensive benefit-risk analysis of clinical trials

BACKGROUND

Numerous acute reperfusion therapies (RPT) are currently investigated as potential new therapeutic targets in acute ischemic stroke (AIS). We conducted a comprehensive benefit-risk analysis of available clinical studies assessing different acute RPT, and investigated the utility of each intervention in comparison to standard intravenous thrombolysis (IVT) and in relation to the onset-to-treatment time (OTT).

METHODS

A comprehensive literature search was conducted to identify all available published, peer-reviewed clinical studies that evaluated the efficacy of different RPT in AIS. Benefit-to-risk ratio (BRR), adjusted for baseline stroke severity, was estimated as the percentage of patients achieving favorable functional outcome (BRR1, mRS score: 0-1) or functional independence (BRR2, mRS score: 0-2) at 3 months divided by the percentage of patients who died during the same period.

RESULTS

A total of 18 randomized (n = 13) and nonrandomized (n = 5) clinical studies fulfilled our inclusion criteria. IV therapy with tenecteplase (TNK) was found to have the highest BRRs (BRR1 = 5.76 and BRR2 = 6.82 for low-dose TNK; BRR1 = 5.80 and BRR2 = 6.87 for high-dose TNK), followed by sonothrombolysis (BRR1 = 2.75 and BRR2 = 3.38), while endovascular thrombectomy with MERCI retriever was found to have the lowest BRRs (BRR1 range, 0.31-0.65; BRR2 range, 0.52-1.18). A second degree negative polynomial correlation was detected between favorable functional outcome and OTT (R (2) value: 0.6419; P < 0.00001) indicating the time dependency of clinical efficacy of all reperfusion therapies.

CONCLUSION

Intravenous thrombolysis (IVT) with TNK and sonothrombolysis have the higher BRR among investigational reperfusion therapies. The combination of sonothrombolysis with IV administration of TNK appears a potentially promising therapeutic option deserving further investigation.

Factors influencing the decline in stroke mortality: a statement from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

Stroke mortality has been declining since the early 20th century. The reasons for this are not completely understood, although the decline is welcome. As a result of recent striking and more accelerated decreases in stroke mortality, stroke has fallen from the third to the fourth leading cause of death in the United States. This has prompted a detailed assessment of the factors associated with the change in stroke risk and mortality. This statement considers the evidence for factors that have contributed to the decline and how they can be used in the design of future interventions for this major public health burden.

METHODS

Writing group members were nominated by the committee chair and co-chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council's Scientific Statements Oversight Committee and the American Heart Association Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiological studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize evidence and to indicate gaps in current knowledge. All members of the writing group had the opportunity to comment on this document and approved the final version. 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

The decline in stroke mortality over the past decades represents a major improvement in population health and is observed for both sexes and for all racial/ethnic and age groups. In addition to the overall impact on fewer lives lost to stroke, the major decline in stroke mortality seen among people <65 years of age represents a reduction in years of potential life lost. The decline in mortality results from reduced incidence of stroke and lower case-fatality rates. These significant improvements in stroke outcomes are concurrent with cardiovascular risk factor control interventions. Although it is difficult to calculate specific attributable risk estimates, efforts in hypertension control initiated in the 1970s appear to have had the most substantial influence on the accelerated decline in stroke mortality. Although implemented later, diabetes mellitus and dyslipidemia control and smoking cessation programs, particularly in combination with treatment of hypertension, also appear to have contributed to the decline in stroke mortality. The potential effects of telemedicine and stroke systems of care appear to be strong but have not been in place long enough to indicate their influence on the decline. Other factors had probable effects, but additional studies are needed to determine their contributions.

CONCLUSIONS

The decline in stroke mortality is real and represents a major public health and clinical medicine success story. The repositioning of stroke from third to fourth leading cause of death is the result of true mortality decline and not an increase in mortality from chronic lung disease, which is now the third leading cause of death in the United States. There is strong evidence that the decline can be attributed to a combination of interventions and programs based on scientific findings and implemented with the purpose of reducing stroke risks, the most likely being improved control of hypertension. Thus, research studies and the application of their findings in developing intervention programs have improved the health of the population. The continued application of aggressive evidence-based public health programs and clinical interventions is expected to result in further declines in stroke mortality.

Solitaire FR as a first-line device in acute intracerebral occlusion: a single-centre retrospective analysis

INTRODUCTION

Analysing the clinical and angiographical effectiveness of the Solitaire FR as a mechanical thrombectomy device in acute intracerebral occlusion.

METHODS

Sixty-two patients were retrospectively included between January 2010 and March 2012. All of them underwent mechanical thrombectomy with the Solitaire FR device with or without intravenous thrombolysis. Twenty-five patients had an occlusion of the basilar artery, 1 had a posterior cerebral artery occlusion. There were 16 M1 middle cerebral artery occlusions, 9 carotid T occlusions and 11 tandem occlusions. Clinical status was evaluated using the National Institute of Health Stroke Scale (NIHSS) before and 24 hours after treatment and at discharge. The Modified Rankin Scale (mRS) was evaluated at 3 months.

RESULTS

Mean age of patients was 64.8 years. Mean NIHSS score on admission was 19.8. Stand-alone thrombectomy was used in 47 patients (75.8%). Recanalization was successful (TICI score 2b or 3) in 23 of 26 (88.5%) patients with posterior circulation occlusion and in 23 of 36 (63.9%) patients with anterior circulation occlusion. NIHSS improved by more than 10 points for 15 of 59 patients with initial NIHSS over 10. MRS was 0-2 in 25 of 62 patients (40.3%). Overall, 23 patients out of 62 died (37%). No complications related to the Solitaire device occurred.

CONCLUSION

These results confirm that the Solitaire FR device is safe and effective in stand-alone thrombectomy.

Interventional neuroradiology of stroke, still not dead

Since the National Institute of Neurological Disorders and Stroke trial, intravenous thrombolysis has been gaining wide acceptance as the modality of treatment for acute embolic stroke, with a current therapeutic window of up to 4.5 h. Both imaging [with either magnetic resonance imaging (MRI) or computed tomography (CT)] and interventional techniques (thrombolysis and/or thrombectomy) have since improved and provided us with additional imaging of the penumbra using CT or MRI and more advanced thrombolysis or thrombectomy strategies that have been embraced in many centers dealing with patients with acute cerebral ischemia. These techniques, however, have come under scrutiny due to their accrued healthcare costs and have been questioned following major recent studies. These studies basically showed that interventional techniques were not superior to the traditional intravenous thrombolysis techniques and that penumbra imaging could not determine what patients would benefit from more aggressive (i.e., interventional) treatment. We discuss this in the light of the latest developments in both diagnostic and interventional neuroradiology and point out why further studies are needed in order to define the right choices for patients with acute stroke. Indeed, these studies were in part conducted with suboptimal patient recruitment strategies and did not always use the latest interventional techniques available today. So, while these studies may have raised some relevant questions, at the same time, definitive answers have not been given, in our opinion.

PPARγ activation rescues mitochondrial function from inhibition of complex I and loss of PINK1

Parkinson's disease has long been associated with impaired mitochondrial complex I activity, while several gene defects associated with familial Parkinson's involve defects in mitochondrial function or 'quality control' pathways, causing an imbalance between mitochondrial biogenesis and removal of dysfunctional mitochondria by autophagy. Amongst these are mutations of the gene for PTEN-induced kinase 1 (PINK1) in which mitochondrial function is abnormal. Peroxisome proliferator-activated receptor gamma (PPARγ), a nuclear receptor and ligand-dependent transcription factor, regulates pathways of inflammation, lipid and carbohydrate metabolism, antioxidant defences and mitochondrial biogenesis. We have found that inhibition of complex I in human differentiated SHSY-5Y cells by the complex I inhibitor rotenone irreversibly decrease mitochondrial mass, membrane potential and oxygen consumption, while increasing free radical generation and autophagy. Similar changes are seen in PINK1 knockdown cells, in which potential, oxygen consumption and mitochondrial mass are all decreased. In both models, all these changes were reversed by pre-treatment of the cells with the PPARγ agonist, rosiglitazone, which increased mitochondrial biogenesis, increased oxygen consumption and suppressed free radical generation and autophagy. Thus, rosiglitazone is neuroprotective in two different models of mitochondrial dysfunction associated with Parkinson's disease through a direct impact on mitochondrial function.

Mechanical thrombectomy for ischaemic stroke: the first UK case series

Background and Purpose

Endovascular treatments have the potential to accelerate reperfusion in acute ischaemic stroke with large vessel occlusion. In the UK only a few stroke centres offer this interventional option. The University Hospital of North Staffordshire (UHNS) has treated the largest number of cases in the UK. Results of the first 106 endovascular treatments (EVT) are presented here.

Methods

All patients treated with EVT (intra-arterial thrombolysis (IAT), mechanical thrombectomy (MT) or both, or an attempt at intervention) for acute stroke at UHNS, Stoke-on-Trent, UK, were entered into a prospective register. Baseline demographic and clinical data, the National Institutes for Health Stroke Scale (NIHSS), imaging results including Thrombolysis in Cerebral Infarction (TICI) score, and complications were recorded. Mortality, and modified Rankin score (mRS) were assessed at 90 days.

Results

From December 2009 to January 2013 106 patients (mean age 64 years, median baseline NIHSS 18) were treated with EVT (thrombectomy ± IAT 83%, IAT alone 13%, neither 4%). Seventy-eight per cent of occlusions were in the anterior circulation. Intravenous bridging thrombolysis was performed in 81%. Revascularization was successful (TICI 2b/3) in 84%. The median time from stroke onset to the end of the procedure was 6 h 03 min. A good outcome (mRS≤2) at 90 days was achieved in 48% with a mortality of 15%. Fatal or nonfatal symptomatic intracranial haemorrhage (sICH) within 10 days occurred in 9%. The median length of stay was 14 days (31% discharged home ≤7 days).

Conclusions

EVT led to good clinical outcomes in almost 50% of patients with severe strokes.

CTA collateral status and response to recanalization in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

Collateral status at baseline is an independent determinant of clinical outcome among patients with acute ischemic stroke. We sought to identify whether the association between recanalization after intra-arterial acute stroke therapy and favorable clinical response is modified by the presence of good collateral flow assessed on baseline CTA.

MATERIALS AND METHODS

Data are from the Keimyung Stroke Registry, a prospective cohort study of patients with acute ischemic stroke from Daegu, South Korea. Patients with M1 segment MCA with or without intracranial ICA occlusions on baseline CTA from May 2004 to July 2009 who also had baseline MR imaging were included. Two readers blinded to all clinical information assessed baseline and follow-up imaging. Leptomeningeal collaterals on baseline CTA were assessed by consensus by use of the regional leptomeningeal score.

RESULTS

Among 84 patients (mean age, 65.2 ± 13.2 years; median NIHSS score, 14; interquartile range, 8.5), median time from stroke onset to initial MR imaging was 164 minutes. TICI 2b-3 recanalization was achieved in 38.1% of patients and mRS 0-2 at 90 days in 35.8% of patients. In a multivariable model, the interaction between collateral status and recanalization was significant. Only patients with intermediate or good collaterals who recanalized showed a statistically significant association with good clinical outcome (rate ratio = 3.8; 95% CI, 1.2-12.1). Patients with good and intermediate collaterals who did not achieve recanalization and patients with poor collaterals, even if they achieved recanalization, did not do well.

CONCLUSIONS

Patients with good or intermediate collaterals on CTA benefit from intra-arterial therapy, whereas patients with poor collaterals do not benefit from treatment.

Fate of the penumbra after mechanical thrombectomy

BACKGROUND AND PURPOSE

In acute stroke, CTP is often used to visualize the endangered brain areas, including the ischemic core and the penumbra. Our goal was to assess the evolution of the infarct after mechanical thrombectomy and to analyze the interventional factors determining the fate of the penumbra.

MATERIALS AND METHODS

All patients receiving mechanical thrombectomy in the anterior circulation and receiving CTP beforehand were identified. The infarct volume was specified. The clinical parameters, outcome, and interventional results were correlated with the CTP and the final infarct size.

RESULTS

In total, 73 patients were included. After mechanical thrombectomy, 78.1% reached a TICI score of 3/2b. The final infarct volume was significantly smaller, with a TICI score of 3/2b compared with less sufficient recanalization (19.60 ± 3 cm(3) versus 38.1 ± 9 cm(3); P < .001). After TICI 3/2b recanalization, 81% ± 5.2% of the potential infarct size (calculated as the sum of infarct core and penumbra) could be rescued. In patients with TICI scores of 2a or worse, only 39 ± 28.3 were salvaged (P < .001). The Alberta Stroke Program Early CT Score after successful recanalization TICI score of 3/2b resulted in a decline of 1.9 ± 1.4 compared with the significantly higher degradation score of 3.7 ± 1.7 after recanalization, with a TICI score of 2a or worse. A recanalization TICI score of 3/2b resulted in an NIHSS improvement of 7.3 ± 0.8 NIHSS points, whereas a poorer recanalization improved on the NIHSS by only 2.5 ± 1.5 points (P < .01).

CONCLUSIONS

Mechanical thrombectomy is a potent method to rescue large areas of penumbra in acute stroke.

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 combination of baseline magnetic resonance perfusion-weighted imaging-derived tissue volume with severely prolonged arterial-tissue delay and diffusion-weighted imaging lesion volume is predictive of MCA-M1 recanalization in patients treated with endovascular thrombectomy

Introduction

Indices of collateral flow deficit derived from MR perfusion imaging that are predictive of MCA-M1 recanalization after intravenous thrombolysis have been recently reported. Our objective was to test the performance of such MRI-derived collateral flow indices for prediction of recanalization after endovascular thrombectomy.

Methods

Fifty-seven patients with MCA-M1 occlusion evaluated with multimodal MRI prior to thrombectomy were included. Bayesian processing allowed quantification of collateral perfusion indices like the volume of tissue with severely prolonged arterial-tissue delay (>6 s) (VolATD6). Baseline DWI lesion volume was also measured. Correlations with angiographic collateral flow grading and post-thrombectomy recanalization were assessed.

Results

VolATD6 < 27 ml or DWI lesion volume <15 ml provide the most accurate diagnosis of excellent collateral supply (p < 0.0001). The combination of VolATD6 > 27 ml and DWI lesion volume >15 ml significantly discriminates recanalizers versus nonrecanalizers (whole cohort, p = 0.032; MERCI cohort (n = 50), p = 0.024). When both criteria are positive, 76.2 % of the patients treated with the MERCI retriever do not fully recanalize (p = 0.024). In multivariate analysis, the aforementioned combined criterion and the angiographic collateral grade are the only independent predictors of recanalization with the MERCI retriever (p = 0.015 and 0.029, respectively).

Conclusion

Bayesian arterial-tissue delay maps and DWI maps provide a non-invasive assessment of the degree of collateral flow and a combined index that is predictive of MCA-M1 recanalization after endovascular thrombectomy. Further studies are needed to evaluate the accuracy of this index in patients treated with novel stent retriever devices.

Advances and challenges in treatment and prevention of ischemic stroke

We review recent advances in the treatment and prevention of acute ischemic stroke, including the current state of endovascular therapy, in light of 5 randomized controlled trials published this past year. Although no benefit of endovascular therapy over intravenous (IV) recombinant tissue plasminogen activator (rt-PA) has been demonstrated, endovascular therapy is an appropriate treatment for acute ischemic stroke patients within the t-PA window who are ineligible for IV t-PA but have a large vascular occlusion. These trials reveal promises and current limitations of endovascular therapy, and comparison of reperfusion therapies remains an important area of research. One common theme is the strong association between a faster time to reperfusion, improved outcome, and reduced mortality. Primary and secondary stroke prevention trials emphasize the importance of aggressive management of medical risk factors as part of any preventative strategy. New oral anticoagulants, for example, offer cost-effective risk reduction in patients with atrial fibrillation, and may represent an opportunity for those with cryptogenic stroke. We highlight areas of unmet need and promising research in stroke, including the need to deliver proven therapies to more patients, and the need to recruit patients into clinical trials that better define the role of endovascular and other stroke therapies. Finally, improvement in strategies to recover speech, cognition, and motor function has the potential to benefit far more stroke patients than any acute stroke therapy, and represents the greatest opportunity for research in the coming century.

Balloon guide catheter improves revascularization and clinical outcomes with the Solitaire device: analysis of the North American Solitaire Acute Stroke Registry

BACKGROUND AND PURPOSE

Efficient and timely recanalization is an important goal in acute stroke endovascular therapy. Several studies demonstrated improved recanalization and clinical outcomes with the stent retriever devices compared with the Merci device. The goal of this study was to evaluate the role of the balloon guide catheter (BGC) and recanalization success in a substudy of the North American Solitaire Acute Stroke (NASA) registry.

METHODS

The investigator-initiated NASA registry recruited 24 clinical sites within North America to submit demographic, clinical, site-adjudicated angiographic, and clinical outcome data on consecutive patients treated with the Solitaire Flow Restoration device. BGC use was at the discretion of the treating physicians.

RESULTS

There were 354 patients included in the NASA registry. BGC data were reported in 338 of 354 patients in this subanalysis, of which 149 (44%) had placement of a BGC. Mean age was 67.3±15.2 years, and median National Institutes of Health Stroke Scale score was 18. Patients with BGC had more hypertension (82.4% versus 72.5%; P=0.05), atrial fibrillation (50.3% versus 32.8%; P=0.001), and were more commonly administered tissue plasminogen activator (51.6% versus 38.8%; P=0.02) compared with patients without BGC. Time from symptom onset to groin puncture and number of passes were similar between the 2 groups. Procedure time was shorter in patients with BGC (120±28.5 versus 161±35.6 minutes; P=0.02), and less adjunctive therapy was used in patients with BGC (20% versus 28.6%; P=0.05). Thrombolysis in cerebral infarction 3 reperfusion scores were higher in patients with BGC (53.7% versus 32.5%; P<0.001). Distal emboli and emboli in new territory were similar between the 2 groups. Discharge National Institutes of Health Stroke Scale score (mean, 12±14.5 versus 17.5±16; P=0.002) and good clinical outcome at 3 months were superior in patients with BGC compared with patients without (51.6% versus 35.8%; P=0.02). Multivariate analysis demonstrated that the use of BGC was an independent predictor of good clinical outcome (odds ratio, 2.5; 95% confidence interval, 1.2-4.9).

CONCLUSIONS

Use of a BGC with the Solitaire Flow Restoration device resulted in superior revascularization results, faster procedure times, decreased need for adjunctive therapy, and improved clinical outcome.

[Current status of endovascular therapy for acute ischemic stroke]

Endovascular therapy (EVT) is performed in patients with acute ischemic stroke due to major artery occlusion, if they were ineligible of intravenous (IV) rt-PA or failure to achieve reperfusion by IV rt-PA. In Japan, intra-arterial thrombolysis has been generally performed, and mechanical thrombectomy using Merci retriever and Penumbra system are gradually spreading. In 2013, the results of three randomized trials (IMS 3, SYNTHESIS expansion, and MR RESCUE) were published, and they could not prove the usefulness of EVT in patients with acute ischemic stroke compared with standard therapy including IV rt-PA. However, these trials suggested important issues of EVT. Especially, adequate selection of patients, improvement of reperfusion rate, and shorter onset to reperfusion time are needed to establish the usefulness of EVT.

[How do the interventional neurologists function in the clinical setting?]

Neuroendovascular therapy is a rapidly evolving clinical subspecialty because of its minimal invasiveness and novel device development. In Japan, neurosurgeons perform a substantial portion of neuroendovascular procedures, however, the number of neurologists who certified by the Japanese Society for Neuroendovascular Therapy (interventional neurologist) is gradually increasing. Neurologists tend to deal with medical treatment in the acute stage and prevention of ischemic stroke, in addition, neuroendovascular procedures for ischemic cerebrovascular diseases performed by neurologists themselves, such as acute revascularization therapy for acute intracranial major artery occlusion or carotid artery stenting, might provide various benefits to ischemic stroke patients because of the smooth, seamless and close management from admission, to intervention, to discharge and after discharge. Because of insufficient number of interventionists to perform emergent neurointerventional procedures in the clinical setting of acute ischemic stroke in Japan, we wish that more neurologists get interested in and receive training in the neuroendovascular therapy.

Imaging Biomarkers for Intra-arterial Stroke Therapy

Despite high rates of early revascularization with intra-arterial stroke therapy, the clinical efficacy of this approach has not been clearly demonstrated. Neuroimaging biomarkers will be useful in future trials for patient selection and for outcomes evaluation. To identify patients who are likely to benefit from intra-arterial therapy, the combination of vessel imaging, infarct size quantification and degree of neurologic deficit appears critical. Perfusion imaging may be useful in specific circumstances, but requires further validation. For measuring treatment outcomes, surrogate biomarkers that appear suitable are angiographic reperfusion as measured by the modified Thrombolysis in Cerebral Infarction scale and final infarct volume.

Can DWI-ASPECTS Substitute for Lesion Volume in Acute Stroke?

Background and Purpose—

The extent of diffusion lesion on pretreatment imaging is a risk factor for poor outcome and hemorrhagic transformation after thrombolysis, and volumes of 70 to 100 mL have been advocated as cut-offs. However, estimating diffusion-weighted imaging (DWI) lesion volume (Vol DWI ) in the acute setting may be cumbersome. We aimed to determine whether the DWI-Alberta Stroke Program Early CT Score (DWI-ASPECTS) can substitute for Vol DWI .

Methods—

DWI-ASPECTS and Vol DWI were measured retrospectively on pretreatment MRI (median onset-to-MRI delay=122 minutes) in 330 consecutively treated patients with middle cerebral artery stroke.

Results—

DWI-ASPECTS and Vol DWI were strongly correlated (ρ=−0.82), but each DWI-ASPECTS point corresponded to a wide range of Vol DWI . All patients with DWI-ASPECTS ≥7 (n=207) had Vol DWI <70 mL, whereas 32 of the 34 patients with DWI-ASPECTS <4 had Vol DWI >100 mL. However, intermediate DWI-ASPECTS (4–6; n=89) corresponded to highly variable Vol DWI (median, 66 mL; interquartile range, 40–98).

Conclusions—

Although each DWI-ASPECTS point corresponds to a wide range of volumes, DWI-ASPECTS <4 or ≥7 may be used as reliable surrogates of Vol DWI >100 or <70 mL, respectively.

Stroke treatment academic industry roundtable: research priorities in the assessment of neurothrombectomy devices

BACKGROUND AND PURPOSE

The goal of the Stroke Treatment Academic Industry Roundtable (STAIR) meetings is to advance the development of stroke therapies. At STAIR VIII, consensus recommendations were developed for clinical trial strategies to demonstrate the benefit of endovascular reperfusion therapies for acute ischemic stroke.

SUMMARY OF REVIEW

Prospects for success with forthcoming endovascular trials are robust, because new neurothrombectomy devices have superior reperfusion efficacy compared with earlier-generation interventions. Specific recommendations are provided for trial designs in 3 populations: (1) patients undergoing intravenous fibrinolysis, (2) early patients ineligible for or having failed intravenous fibrinolysis, and (3) wake-up and other late-presenting patients. Among intravenous fibrinolysis-eligible patients, key principles are that CT or MRI confirmation of target arterial occlusions should precede randomization; endovascular intervention should be pursued with the greatest rapidity possible; and combined intravenous and neurothrombectomy therapy is more promising than neurothrombectomy alone. Among patients ineligible for or having failed intravenous fibrinolysis, scientific equipoise was affirmed and the need to randomize all eligible patients emphasized. Vessel imaging to confirm occlusion is mandatory, and infarct core and penumbral imaging is desirable in later time windows. Additional STAIR VIII recommendations include approaches to test multiple devices in a single trial, utility weighting of disability end points, and adaptive designs to delineate time and tissue injury thresholds at which benefits from intervention no longer accrue.

CONCLUSIONS

Endovascular research priorities in acute ischemic stroke are to perform trials testing new, highly effective neuro thrombectomy devices rapidly deployed in patients confirmed to have target vessel occlusions.

"Imaging Evaluation of Collaterals in the Brain: Physiology and Clinical Translation"

The cerebral collateral circulation is a network of blood vessels designed to preserve cerebral blood flow when primary routes fail. Though recognized for hundreds of years, the beneficial influence of collateral flow has now gained significant attention due to widely available, rapid, and real-time non-invasive imaging techniques. Multimodal CT and MRI based techniques, with angiographic and perfusion assessments, are becoming mainstays in the care of patients with ischemic brain disease. These methods allow for precise delineation of the structural and functional aspects of cerebral blood flow and as such provide valuable information that can inform the diagnosis and treatment of cerebral ischemia, in both the acute and chronic setting.

[Quality parameters in the treatment of acute stroke: comparison of various regional treatment concepts]

BACKGROUND

The long-term prognosis of stroke patients is still dependent in particular on the timing of a correct diagnosis, immediate initiation of a suitable specific therapy and competent treatment in a stroke unit. Therefore, nationwide attempts are being made to establish a comprehensive coverage of the necessary specific competence and infrastructural requirements. Divergent regional circumstances and economic viewpoints determine the characteristics of the various healthcare concepts and the interplay between participating cooperation partners. This article compares the development with respect to three qualitative treatment parameters exemplified by four regional healthcare models during the time period 2008-2011.

METHODS

The hospitalization rates for patients with transitory ischemic attacks, ischemic and hemorrhagic stroke, the case numbers for stoke unit treatment and the rates of systemic thrombolysis and mechanical thrombectomy in the regions of Berlin, the Ruhr Area, Ostwestfalen-Lippe and southeast Bayern (TEMPiS) are presented based on the data from the DRG statistical reports for the years 2008 and 2011.

RESULTS

The average hospitalization rates for ischemic stroke patients (brain infarct ICD 163) in the time period from 2008 to 2011 were 294 per 100,000 inhabitants for the Ruhr Area, 257 per 100,000 inhabitants for Ostwestfalen-Lippe and 265 per 100,000 inhabitants each for Berlin and southeast Bayern. The complex stroke treatment quota for southeast Bayern in 2008 was 31 % and 47 % in 2011 and the respective quotas for the other regions studied were 42-44 % and 58-59 %. The rate of systemic thrombolysis in 2008 ranged between 4.2 % and 7.4 % and in 2011 the increase in the range for the 4 regions studied was between 41 % and 145 %. In 2011 the thrombectomy quota of 2 % in the Ruhr Area was the only one which was above the national average of 1.3 % of all brain infarcts.

DISCUSSION

Stroke is a common disease in the four regions studied. For the established forms of therapy, complex treatment of stroke and systemic thrombolysis, the positive effect of structurally improved approaches in the four different regional treatment concepts could be confirmed during the course of the observational time period selected. Mechanical thrombectomy which is currently still considered to be an individual healing attempt, was used significantly more often in the Ruhr Area in 2011 than in the other three regions studied. A standardized referral procedure had previously been established in the metropolitan regions.

Thrombectomy in patients with large cerebral artery occlusion: a single-center experience with a new stent retriever

INTRODUCTION

The Trevo device, a new stent retriever, may be utilized in patients with large cerebral artery occlusion.

METHODS

Fifty patients with large cerebral artery occlusion and treated with the Trevo device were analyzed. Patients may have received intravenous thrombolysis as a bridging concept in addition to thrombectomy. Outcome and recanalization parameters were documented using the National Institutes of Health Scale, the modified Ranking Scale (mRS) and Thrombolysis in Cerebral Infarction (TICI) score.

RESULTS

In all, 82% (95% confidence interval [CI]: 69%-91%) were documented with TICI 2b and 3. Good clinical outcome after 90 days (mRS ≤ 2) was assessed in 61% (95% CI: 46%-75%). Symptomatic intracerebral hemorrhage occurred in 6 patients (12%, 95% CI: 1%-17%). The overall mortality rate was 14% (95% CI: 6%-27%).

CONCLUSION

Thrombectomy with the new stent retriever device is feasible and effective and has an acceptable risk of intra-cerebral hemorrhage even in combination with pharmacological revascularization techniques.

Translational Perspectives on Perfusion–Diffusion Mismatch in Ischemic Stroke

Magnetic resonance imaging has tremendous potential to illuminate ischemic stroke pathophysiology and guide rational treatment decisions. Clinical applications to date have been largely limited to trials. However, recent analyses of the major clinical studies have led to refinements in selection criteria and improved understanding of the potential implications for the risk vs. benefit of thrombolytic therapy. In parallel, preclinical studies have provided complementary information on the evolution of stroke that is difficult to obtain in humans due to the requirement for continuous or repeated imaging and pathological verification. We review the clinical and preclinical advances that have led to perfusion–diffusion mismatch being applied in phase 3 randomized trials and, potentially, future routine clinical practice.

A Multicenter, Randomized, Controlled Study to Investigate Extending the Time for Thrombolysis in Emergency Neurological Deficits with Intra-Arterial Therapy (EXTEND-IA)

Background and Hypothesis

Thrombolysis with tissue plasminogen activator is proven to reduce disability when given within 4.5 h of ischemic stroke onset. However, tissue plasminogen activator only succeeds in recanalizing large vessel arterial occlusion in a minority of patients. We hypothesized that anterior circulation ischemic stroke patients, selected with ‘dual target’ vessel occlusion and evidence of salvageable brain using computed tomography or magnetic resonance imaging ‘mismatch’ within 4.5 h of onset, would have improved reperfusion and early neurological improvement when treated with intra-arterial clot retrieval after intravenous tissue plasminogen activator compared with intravenous tissue plasminogen activator alone.

Study Design

EXTEND-IA is an investigator-initiated, phase II, multicenter prospective, randomized, open-label, blinded-endpoint study. Ischemic stroke patients receiving standard 0.9 mg/kg intravenous tissue plasminogen activator within 4.5 h of stroke onset who have good prestroke functional status (modified Rankin Scale <2, no upper age limit) will undergo multimodal computed tomography or magnetic resonance imaging. Patients who also meet dual target imaging criteria: vessel occlusion (internal carotid or middle cerebral artery) and mismatch (perfusion lesion: ischemic core mismatch ratio >1.2, absolute mismatch >10 ml, ischemic core volume <70 ml) will be randomized to either clot retrieval with the Solitaire FR device after full dose intravenous tissue plasminogen activator, or tissue plasminogen activator alone.

Study Outcomes

The coprimary outcome measure will be reperfusion at 24 h and favorable clinical response (reduction in National Institutes of Health Stroke Scale by ≥8 points or reaching 0–1) at day 3. Secondary outcomes include modified Rankin Scale at day 90, death, and symptomatic intracranial hemorrhage.

Elderly patients and intra-arterial stroke therapy

Ischemic stroke disproportionately affects the elderly, particularly those over the age of 80 years. Rates of stroke are expected to increase over the next several decades due to increasing numbers of elderly individuals, making understanding stroke treatment in this population an imperative. The only proven acute stroke therapy is early reperfusion, accomplished through intravenous or intra-arterial means. Intra-arterial stroke therapy (IAT) offers higher recanalization rates than intravenous tissue plasminogen activator, but has yet to show clear superiority over intravenous tissue plasminogen activator alone. Existing data suggest that elderly stroke patients suffer worse outcomes following IAT, despite similar rates of recanalization and symptomatic intracranial hemorrhage. This article reviews the application of IAT in the elderly population and summarizes the available studies that investigate the response of elderly patients to IAT.

Emergency cervical internal carotid artery stenting in combination with intracranial thrombectomy in acute stroke

BACKGROUND AND PURPOSE

In past years, thrombectomy has become a widely used procedure in interventional neuroradiology for the treatment of acute intracranial occlusions. However, in 10-20% of patients, there are additional occlusions or stenotic lesions of the ipsilateral cervical internal carotid artery. The purpose of this study was to evaluate the feasibility of emergency carotid artery stent placement in combination with intracranial thrombectomy and the clinical outcome of the treated patients.

MATERIALS AND METHODS

We analyzed clinical and angiographic data of patients who underwent emergency cervical ICA stent placement and intracranial thrombectomy with stent-retriever devices in our institution between November 2009 and July 2012. Recanalization was assessed according to the Thrombolysis in Cerebral-Infarction score. Clinical outcome was evaluated at discharge (NIHSS) and after 3 months (mRS).

RESULTS

Overall, 24 patients were treated. The mean age was 67.2 years; mean occlusion time, 230.2 minutes. On admission, the median NIHSS score was 18. In all patients, the Thrombolysis in Cerebral Infarction score was zero before the procedure. Stent implantation was feasible in all cases. In 15 patients (62.5%), a Thrombolysis in Cerebral Infarction score ≥ 2b could be achieved. Six patients (25%) improved ≥10 NIHSS points between admission and discharge. After 90 days, the median mRS score was 3.0. Seven patients (29.2%) had a good clinical outcome (mRS 0-2), and 4 patients (16.6%) died, 1 due to fatal intracranial hemorrhage. Overall, symptomatic intracranial hemorrhage occurred in 4 patients (16.6%).

CONCLUSIONS

Emergency ICA stent implantation was technically feasible in all patients, and the intracranial recanalization Thrombolysis in Cerebral Infarction score of ≥2b was reached in a high number of patients. Clinical outcome and mortality seem to be acceptable for a cohort with severe stroke. However, a high rate of symptomatic intracranial hemorrhage occurred in our study.

Rapid Short MRI Sequence Useful in Eliminating Stroke Mimics Among Acute Stroke Patients Considered for Intravenous Thrombolysis

BACKGROUND

Acute stroke teams are challenged by IV-tPA decision making in patients with acute neurological symptoms when the diagnosis is unclear. The purpose of this study was to evaluate the ability of the rapid Brain Attack Team (BAT) MRI in selecting patients for IV-tPA administration who present acutely to the emergency room with stroke-like symptoms and an unclear diagnosis.

METHODS

Consecutive patients were identified who presented within 4.5 hours of onset of stroke-like symptoms and considered for treatment with IV-tPA. When the diagnosis was not clear, a 9-minute BAT MRI was obtained. Stroke risk factors and NIH stroke scale obtained on presentation were compared between patients in whom BAT MRI was obtained and those in whom BAT MRI was not obtained. Similarly, comparisons were made between patients in whom BAT MRI detected abnormalities and those in whom BAT MRI did not detect abnormalities. BAT MRIs were analyzed to determine if radiological findings impacted clinical management and discharge diagnosis.

RESULTS

In a 30-month period, 432 patients presenting with acute stroke-like symptoms were identified. Of these patients, 82 received BAT MRI. Patients receiving BAT MRI were younger, more likely to be smokers, and less likely to be selected for IV-tPA administration compared to those in whom a more definitive diagnosis of stroke precluded a BAT MRI. Of the 82 BAT MRIs, 25 were read as positive for acute ischemia. The patients with acute ischemia on BAT MRI were older, more likely to be males, have a history of hypercholesterolemia and atrial fibrillation, and more likely to be selected for IV-tPA administration compared to those with a negative BAT MRI. Of the 57 BAT MRIs read as negative for acute ischemia or hemorrhage, discharge diagnoses included TIA, MRI negative stroke, conversion/functional disorder, and multiple other illnesses.

CONCLUSION

In patients with acute stroke-like symptoms, BAT MRI may be used to confirm acute ischemic stroke, exclude stroke mimics, and assess candidacy for IV-tPA.

Mechanical thrombectomy with the Solitaire stent: is there a learning curve in achieving rapid recanalization times?

METHODS

In acute ischemic stroke, good outcome following successful recanalization is time dependent. In patients undergoing endovascular therapy at our institution, recanalization times with the Solitaire stent were retrospectively evaluated to assess for the presence of a learning curve in achieving rapid recanalization.

METHODS

We reviewed patients who presented to our stroke center and achieved successful recanalization with the Solitaire stent exclusively. Time intervals were calculated (CT to angiography arrival, angiography arrival to groin puncture, groin puncture to first deployment, and deployment to recanalization) from time stamped images and angiography records. Patients were divided into three sequential groups, with overall CT to recanalization time and subdivided time intervals compared.

RESULTS

83 patients were treated with the Solitaire stent from May 2009 to February 2012. Recanalization (Thrombolyis in Cerebral Infarction score 2A) occurred in 75 (90.4%) patients. CT to recanalization demonstrated significant improvement over time, which was greatest between the first 25 and the most recent 25 cases (161-94 min; p<0.01). The maximal contribution to this was from improvements in first stent deployment to recanalization time (p=0.001 between the first and third groups), with modest contributions from moving patients from CT to the angiography suite faster (p=0.02 between the first and third groups) and from groin puncture to first stent deployment (p=0.02 between the first and third groups).

CONCLUSIONS

There is a learning curve involved in the efficient use of the Solitaire stent in endovascular acute stroke therapy. Along with improvements in patient transfer to angiography and improved efficiency with intracranial access, mastering this device contributed significantly towards reducing recanalization times.

ASPECTS is a predictor of favorable CT perfusion in acute ischemic stroke

BACKGROUND AND PURPOSE

Computed tomography perfusion (CTP) is used by some stroke centers to stratify stroke patients who may potentially benefit from endovascular treatment. Our aim is to identify predictors of a favorable CTP in acute ischemic stroke patients evaluated within 8h from symptoms onset for possible endovascular treatment.

MATERIALS AND METHODS

We reviewed records of patients who had CTP studies between August 2010 and September 2012. We included all patients with anterior circulation strokes with evidence of large vessel disease. All patients had CT head and CT angiography head and neck as part of our protocol. Favorable CTP was defined as core infarct size less than one third the middle cerebral artery distribution and penumbra>20% of infarct size. The patients were divided into two groups based on favorable CTP or not. Baseline characteristics, time parameters, laboratory data and radiological data were compared between both groups. For statistical analysis, we used independent and Fisher's exact tests and a multivariate logistic regression model.

RESULTS

During this period, 60 patients met the inclusion criteria. Patients with favorable CTP were likely to be ≥ 80 years (33% vs 9%, P = 0.026), have Alberta Stroke Program early CT score (ASPECTS) > 7 (81% v. 21%, P ≤ 0.001) and lower mean time from symptom onset to CTP (234 ± 91 vs 305 ± 122, P = 0.015). On regression analysis, ASPECTS was the only independent predictor of a favorable CTP (OR = 16.2, CI: 4.3-62.2, P < 0.001).

CONCLUSION

ASPECT score may be used as a tool to predict a favorable CTP. Larger studies are needed to confirm our findings.

The goldilocks dilemma in acute ischemic stroke

Despite the advent of and exciting advances in novel endovascular therapies, t-PA remains the only proven treatment for acute ischemic stroke to date. Although a variety of reasons likely underlie why past trials of endovascular strategies have been unsuccessful, we address in this perspective piece one critical unknown for which a solution is undoubtedly necessary if future ones are to meet with success: determination and selection of patients that are “just right” for endovascular treatments, or the Goldilocks dilemma. Key clinical criteria highlighted in past trials may help provide a solution to this critical problem. However, for them to do so, we propose that they must be applied in service of a model that accounts for the nuanced, dynamic nature of acute ischemic stroke better than the prevailing “time is brain” model. We provide and examine three clinical cases to illustrate this proposal towards solving the Goldilocks dilemma and advancing treatment in acute ischemic stroke. Further, we address our field’s ongoing challenge and mission in the meantime to best care for the “not-so-right” patients, by far the majority of the affected stroke population.

[IMSIII, SYNTHESIS, and MR-RESCUE studies: the end of endovascular treatment for stroke?]

Last March, in a single issue New England Journal of Medicine published 3 studies that evaluated the efficacy of endovascular treatment for ischemic stroke, leading to a heated controversy between neurologists and interventional neuroradiologists. The negative results have resulted in numerous reviews pointing out serious methodological defects. In this article, we analyze the outcomes of thrombolytic treatment for stroke and discuss the strengths and weaknesses of the three above-mentioned studies. Despite the negative results, these studies can point the way for new trials that will justify this treatment modality that is backed up by scientific evidence.

Neurothrombectomy in the treatment of acute ischaemic stroke

Major ischaemic stroke is a leading cause of morbidity and mortality in industrialized countries. For patients with acute stroke, fast and effective vessel recanalization is important for successful treatment. Neurothrombectomy--that is, angiographically performed mechanical thrombus removal from intracranial arteries--results in higher recanalization rates than with pharmaceutical thrombolysis alone, but the value of this treatment in terms of clinical outcome remains to be established. This article summarizes the history of intra-arterial stroke treatment, outlines the recent developments and the different techniques used, and discusses the results of current studies on neurothrombectomy. Owing to the high morphological and clinical variability of stroke, careful patient selection in future randomized controlled trials will be crucial for assessment of the true potential of neurothrombectomy.

The outcome and efficacy of recanalization in patients with acute internal carotid artery occlusion

BACKGROUND AND PURPOSE

Acute occlusion of the ICA is often associated with poor outcomes and severe neurologic deficits. This study was conducted to evaluate outcome of the occluded ICA and efficacy of recanalization under protective flow arrest.

MATERIALS AND METHODS

Fifty consecutive patients who underwent endovascular treatment for acute ICA occlusion were identified from the prospectively collected data base. We assessed NIHSSo, occlusion type (cardioembolism vs atherosclerosis), occlusion level (supraclinoid-terminal, petrocavernous, or bulb-cervical), recanalization degree (TICI), and efficacy of recanalization (protective flow arrest vs nonprotection) leading to better outcome.

RESULTS

Successful recanalization (TICI ≥ 2) was obtained in 90% of patients and good recovery (mRS ≤ 2) in 60% of patients. Good outcome was related to National Institutes of Health Stroke Scale score on admission (P < .001), TICI (P < .007), occlusion type (P = .022), and occlusion level (P = .038). Poor initial patient status, less recanalization, cardioembolism, and supraclinoid-terminal occlusion were associated with poor prognosis. Application of protective flow arrest led to better outcome in the distal ICA segment than in the bulb-cervical segment.

CONCLUSIONS

In addition to the initial patient status and successful recanalization, the occlusion level or type of the occluded ICA could affect clinical outcome. In this study, treatment benefits of protective flow arrest were accentuated in patients with ICA occlusion above the bulb-cervical segment.

Endovascular therapy for acute ischemic stroke: a systematic review and meta-analysis

OBJECTIVE

To consolidate the evidence from randomized trials for the use of endovascular therapy (ET) in patients with acute ischemic stroke.

METHODS

We searched major databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus) from their inception to February 12, 2013, for randomized trials evaluating the efficacy of ET compared with standard of care for acute ischemic stroke. Pooled absolute and relative risk estimates were synthesized by using a random-effects model. Heterogeneity was assessed by using Q statistic and I(2) statistic. Subset analysis was performed for patients with severe stroke (National Institutes of Health Stroke Scale score ≥20). The study was conducted from January 15, 2013 to April 30, 2013.

RESULTS

Of the 1252 retrieved articles, 5 randomized trials enrolling 1197 patients with acute ischemic stroke were included. Seven hundred eleven patients received ET, and 486 received intravenous (IV) tissue plasminogen activator. There was no significant improvement in any of the outcomes in patients receiving ET compared with those receiving IV thrombolysis. On subgroup analysis, ET was found to have better outcomes in patients with severe stroke (National Institutes of Health Stroke Scale score ≥20), showing a dose-response gradient and improving excellent, good, and fair outcomes by an additional 4%, 7%, and 13%, respectively, compared with IV thrombolysis.

CONCLUSION

Overall, ET is not superior to IV thrombolysis for acute ischemic strokes (level B recommendation). However, ET showed promise and improved outcomes in patients with severe strokes, but the evidence is limited due to sample size. There is a need for further trials evaluating the role of ET in this high-risk group.

THRIVE score predicts outcomes with a third-generation endovascular stroke treatment device in the TREVO-2 trial

BACKGROUND AND PURPOSE

Several outcome prediction scores have been tested in patients receiving acute stroke treatment with previous generations of endovascular stroke treatment devices. The TREVO-2 trial was a randomized controlled trial comparing a novel endovascular stroke treatment device (the Trevo device) to a previous-generation endovascular stroke treatment device (the Merci device).

METHODS

We used data from the TREVO-2 trial to validate the Totaled Health Risks in Vascular Events (THRIVE) score in patients receiving treatment with a third-generation endovascular stroke treatment device and to compare THRIVE to other predictive scores. We used logistic regression to model outcomes and compared score performance with receiver operating characteristic curve analysis.

RESULTS

In the TREVO-2 trial, the THRIVE score strongly predicts clinical outcome and mortality. The relationship between THRIVE score and outcome is not influenced by either success of recanalization or the type of device used (Trevo versus Merci). The superiority of the Trevo device to the Merci device is evident particularly among patients with a low-to-moderate THRIVE score (0-5; 53.8% good outcome with Trevo versus 27.5% good outcome with Merci). In receiver operating characteristic curve analysis, the THRIVE score was comparable or superior to several other outcome prediction scores (HIAT, HIAT-2, SPAN-100, and iScore).

CONCLUSIONS

The THRIVE score strongly predicts clinical outcome and mortality in the TREVO-2 trial. Taken together with THRIVE validation data from patients receiving intravenous tissue-type plasminogen activator or no acute treatment, the THRIVE score has broad predictive power in patients with acute ischemic stroke, which is likely because THRIVE reflects a set of strong nonmodifiable predictors of stroke outcome. A free Web calculator for the THRIVE score is available at http://www.thrivescore.org.