Number needed to treat to benefit and to harm for intravenous tissue plasminogen activator therapy in the 3- to 4.5-hour window: joint outcome table analysis of the ECASS 3 trial

Impact of Protocol Deviations in Acute Ischemic Stroke Treated With Intravenous rt-PA Within 4.5 Hours After Symptom Onset

BACKGROUND

There is limited experience in the community with intravenous tissue plasminogen activator (rt-PA) administered 3 to 4.5 hours after acute ischemic stroke (AIS) onset. Many patients do not meet entry criteria of pivotal clinical trials because of severe stroke, age >80, severe hypertension (sHTN), or history of previous stroke and diabetes. Whether rt-PA benefits these patients is unclear. Thus, we investigated the outcomes of stroke patients treated with rt-PA with or without these adverse clinical characteristics.

METHODS

Chart review of patients with AIS treated with intravenous rt-PA at a single institution. Outcomes at discharge were compared between patients with severe stroke, age >80, sHTN, or previous stroke/diabetes and those without these characteristics. Good outcome was defined as modified Rankin score (mRS) of 0 to 1. Analysis of variance and t tests were used to compare the outcomes.

RESULTS

Of the 118 cases analyzed, 103 (87%) were treated ≤3 hours and 15 (13%) between 3 and 4.5 hours. Sixty-three (53%) patients had severe stroke, age >80, sHTN, or previous stroke/diabetes, whereas 55 (47%) did not. Compared to controls, patients with these adverse characteristics were less likely to have good outcomes (35% vs 56%, p = .02). No patients treated within the 3- to 4.5-hour window experienced symptomatic intracranial hemorrhage (sICH). Eight patients treated between 3 and 4.5 hours had severe stroke, age >80, sHTN, or previous stroke/diabetes. Of these, 6 had poor outcomes.

CONCLUSIONS

In a highly selected group of patients treated with intravenous rt-PA, lack of adherence to current guidelines did not improve stroke outcomes. This was related to more severe strokes at baseline, not sICH. Prospective studies of this patient group are needed.

Unanswered questions in thrombolytic therapy for acute ischemic stroke

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

Intravenous thrombolysis for acute ischemic stroke associated to extracranial internal carotid artery occlusion: the ICARO-2 study

BACKGROUND AND PURPOSES

In a case-control study in patients with acute ischemic stroke and extracranial internal carotid artery (eICA) occlusion, thrombolytic treatment was associated with increased mortality. The aim of this cohort study was to assess the efficacy and safety of thrombolysis in patients with eICA occlusion compared to those without eICA occlusion.

METHODS

Consecutive patients treated with intravenous tissue-type plasminogen activator within 4.5 h from symptom onset included in the Safe Implementation of Thrombolysis in Stroke - International Stroke Thrombolysis Registry (SITS-ISTR) in 20 Italian centres were analyzed. Acute carotid occlusion was diagnosed using ultrasound examination, angio-CT scan or angio-MRI. Since the SITS-ISTR database did not plan to report the site of vessel occlusion, each participating center provided the code of the patient with eICA occlusion. Patients were divided into 2 groups, those with and those without eICA occlusion. Main outcome measures were: death, disability (modified Rankin Scale, mRS, 3-6) and any intracranial bleeding at 3 months. Multiple logistic regression analysis was performed to reveal predictors for main outcomes. The following variables of interest were included in the analysis: presence of eICA occlusion, age, gender, diabetes mellitus, hyperlipidemia, atrial fibrillation, congestive heart failure, previous stroke, current smoking, antiplatelet treatment at stroke onset, baseline NIHSS score, baseline blood glucose, cholesterol and blood pressure, history of hypertension and stroke onset to treatment time.

RESULTS

A total of 1,761 patients without eICA occlusion and 137 with eICA occlusion were included in the study. At 3 months, 42 patients were lost to follow-up (3 with eICA occlusion). Death occurred in 30 (22.4%) patients with eICA occlusion and in 175 (10.2%) patients without (p < 0.0001). Death or disability at 3 months occurred in 91 of 134 patients with eICA occlusion (67.9%) compared with 654 of 1,722 patients without eICA occlusion (37.9%, p < 0.0001). No or minimal disability at 3 months (mRS 0-1) was reported in 25 (18.7%) patients with eICA occlusion and in 829 (48.2%) patients without (p < 0.0001). Any intracranial bleeding detected by CT or MRI at posttreatment imaging was seen in 16 (11.7%) patients with eICA occlusion and in 314 (17.8%) of those without (p = 0.09). The proportion of symptomatic intracerebral hemorrhage was 5.8% for patients with eICA occlusion and 8.0% for patients without (p = 0.16). At logistic regression analysis, eICA occlusion was associated with mortality (odds ratio, OR 5.7; 95% confidence interval, CI 2.9-11.1) and mortality or disability (OR 5.0; 95% CI 2.9-8.7) at 90 days.

CONCLUSIONS

This cohort study in patients with acute ischemic stroke treated with thrombolysis showed an association between eICA occlusion and adverse outcome.

[Dysfunction of the blood-brain barrier during ischaemia: a therapeutic concern]

Since it was discovered and its brain-protective role characterized, the blood-brain barrier (BBB), through the permeability-restricting action of the brain capillary endothelial cells, has been representing a hurdle for 95% of new medical compounds targeting the central nervous system. Recently, a BBB dysfunction is being found in an increasing number of pathologies such as brain ischaemic stroke, whose only therapy consists in a pharmacological thrombolysis limited to a small percentage of the admitted patients, because of the toxical effects of thrombolytics. And since the clinical failure of promising neuroprotectants, numerous studies of brain ischaemia were carried out, with physiopathological or pharmacological approaches refocused on the BBB, whose structural complexity is now expanded to perivascular cells, all forming a functional unit named the neurovascular unit (NVU). Nevertheless, in spite of the numerous molecular mechanisms identified, the process of BBB dysfunction in the ischaemia/reperfusion cascade remains insufficiently established to explain the pleiotropic action exerted by new pharmacological compounds, possibly protecting the entire NVU and representing potential treatments.

Does mechanical thrombectomy in acute embolic stroke have long-term side effects on intracranial vessels? An angiographic follow-up study

PURPOSE

Mechanical thrombectomy (mTE) proved to be effective treating acute vessel occlusions with an acceptable rate of procedural complications. Potential long-term side effects of the vessel wall trauma caused by mechanical irritation of the endothelium are unknown up to now.

METHODS

From a retrospectively established database of 640 acute stroke treatments, we selected 261 patients with 265 embolic vessel occlusions treated successfully by mTE without permanent implantation of a stent. Analysis comprised the type of devices used and the number of passes performed. Digital subtraction angiography immediately after treatment was evaluated for vasospasm, dissection, and extravasation. Control angiographic images were evaluated for any morphological change compared to the immediate posttreatment angiographic run.

RESULTS

Recanalization was achieved with a median of one (range 1-10) mTE maneuvers. Vasospasm occurred in 69 territories (26.0 %) and was treated with glyceroltrinitrate in three. Dissection was observed in one vessel (0.4 %). Intraprocedural hemorrhage in two patients (0.8 %) was either wire or device induced. Follow-up digital subtraction angiography was available for 117 territories after a median of 107 days, revealing target vessel occlusion in one segment (0.9 %) and a de novo stenosis of four segments (3.4 %). All findings were clinically asymptomatic. Posttreatment vasospasm was more frequent in patients with de novo stenosis and occlusion (p = 0.038).

CONCLUSION

De novo stenoses and occlusions occur in a small proportion of patients after mTE. Because all lesions were clinically asymptomatic, this finding does not affect the overall benefit of the treatment. Vasospasm may predict late vessel wall changes.

Transcranial near-infrared laser therapy applied to promote clinical recovery in acute and chronic neurodegenerative diseases

One of the most promising methods to treat neurodegeneration is noninvasive transcranial near-infrared laser therapy (NILT), which appears to promote acute neuroprotection by stimulating mitochondrial function, thereby increasing cellular energy production. NILT may also promote chronic neuronal function restoration via trophic factor-mediated plasticity changes or possibly neurogenesis. Clearly, NILT is a treatment that confers neuroprotection or neurorestoration using pleiotropic mechanisms. The most advanced application of NILT is for acute ischemic stroke based upon extensive preclinical and clinical studies. In laboratory settings, NILT is also being developed to treat traumatic brain injury, Alzheimer's disease and Parkinson's disease. There is some intriguing data in the literature that suggests that NILT may be a method to promote clinical improvement in neurodegenerative diseases where there is a common mechanistic component, mitochondrial dysfunction and energy impairment. This article will analyze and review data supporting the continued development of NILT to treat neurodegenerative diseases.

Endothelial cells and astrocytes: a concerto en duo in ischemic pathophysiology

The neurovascular/gliovascular unit has recently gained increased attention in cerebral ischemic research, especially regarding the cellular and molecular changes that occur in astrocytes and endothelial cells. In this paper we summarize the recent knowledge of these changes in association with edema formation, interactions with the basal lamina, and blood-brain barrier dysfunctions. We also review the involvement of astrocytes and endothelial cells with recombinant tissue plasminogen activator, which is the only FDA-approved thrombolytic drug after stroke. However, it has a narrow therapeutic time window and serious clinical side effects. Lastly, we provide alternative therapeutic targets for future ischemia drug developments such as peroxisome proliferator- activated receptors and inhibitors of the c-Jun N-terminal kinase pathway. Targeting the neurovascular unit to protect the blood-brain barrier instead of a classical neuron-centric approach in the development of neuroprotective drugs may result in improved clinical outcomes after stroke.

Intravenous Thrombolysis in Expanded Time Window (3-4.5 hours) in General Practice with Concurrent Availability of Endovascular Treatment

INTRODUCTION

A randomized double-blind trial (ECASS III) demonstrated that intravenous (IV) recombinant tissue plasminogen activator (rt-PA) administered between 3 and 4.5 hrs after the onset of symptoms significantly improved clinical outcomes in patients with acute ischemic stroke. In May 2009, the American Stroke Association guidelines recommended the use of IV rt-PA for patients presenting within 3 and 4.5 hrs after symptom onset.

OBJECTIVE

To determine the rate of patients treated with IV rt-PA within the 3- and 4.5-hr time window and associated comparative outcomes in general practice.

METHODS

We retrospectively reviewed all patients who were treated with IV rt-PA at two comprehensive stroke centers from September 1, 2008 to July 31, 2010 and identified a total of 98 patients. In addition, we identified patients who arrived to the ED of those centers within 2.5 to 4 hrs of symptom onset between January 1, 2007 and June 30, 2010 and received only endovascular treatment. We compared the rates of favorable outcome (determined by using modified Rankin scale 0-2 at discharge and 3-month follow-up), and National Institutes of Health Stroke Scale (NIHSS) score improvement by ≥ 4 points or 0 at discharge among patients treated with IV rt-PA within 3-4.5 hrs with those who received IV rt-PA within 0-3 hrs, and subsequently with patients presenting at similar time window treated only with endovascular treatment.

RESULT

Out of the total 98 IV rt-PA treated patients, 84 of them were treated within 0-3 hrs, and 14 within the 3--4.5 hrs. Twelve patients received endovascular treatment only for the specified time window. Mean admission NIHSS score ± standard deviation (SD) was 11.90 ± 6.72, 8.57 ± 5.40, and 11.75 ± 8.06, for the 0--3, 3--4.5 hrs, and endovascular only treatment groups, respectively. Favorable clinical outcome at discharge (50% vs. 56%, p=0.77), 3 months (64% vs. 64%, p=1.0), and NIHSS score improvement (43% vs. 58%, p=0.38) were not different between those treated within 3-4.5 and 0-3 hrs time windows. There appeared to be a non-significantly higher rate of favorable outcomes at discharge (25% vs. 50%, p=0.24), and at 3 months (42% vs. 64%, p=0.43) among patients treated with IV rt-PA within 3-4.5 hrs compared with those treated with primary endovascular treatment.

CONCLUSION

An additional 14% of patients received IV rt-PA because of treatment window expansion from 3 to 4.5 hrs. Outcomes were comparable to those treated within 3 hrs of symptom onset. The shift of those patients from primary endovascular treatment does not appear to adversely affect patient outcomes.

Eligibility for Intravenous Recombinant Tissue-Type Plasminogen Activator Within a Population: The Effect of the European Cooperative Acute Stroke Study (ECASS) III Trial

BACKGROUND AND PURPOSE

The publication of the European Cooperative Acute Stroke Study (ECASS III) expanded the treatment time to thrombolysis for acute ischemic stroke from 3 to 4.5 hours from symptom onset. The impact of the expanded time window on treatment rates has not been comprehensively evaluated in a population-based study.

METHODS

All patients with an ischemic stroke presenting to an emergency department during calendar year 2005 in the 17 hospitals that compromise the large 1.3 million Greater Cincinnati/Northern Kentucky population were included in the analysis. Criteria for exclusion from thrombolytic therapy are analyzed retrospectively for both the standard and expanded timeframes with varying door-to-needle times.

RESULTS

During the study period, 1838 ischemic strokes presenting to an emergency department were identified. A small proportion of them arrived in the expanded time window (3.4%) compared with the standard time window (22%). Only 0.5% of those who arrived in this timeframe met eligibility criteria for thrombolysis compared with 5.9% using standard eligibility criteria in the standard timeframe. These results did not vary significantly by repeated analysis varying the door-to-needle time or the expanded time window's exclusion criteria.

CONCLUSIONS

In reality, the expanded time window for thrombolysis in acute ischemic stroke benefits few patients. If we are to improve recombinant tissue-type plasminogen activator administration rates, our focus should be on improving stroke awareness, transport to facilities with ability to administer thrombolysis, and familiarity of physicians with acute stroke treatment guidelines.

Beyond the time window of intravenous thrombolysis: standing by or by stenting?

Intravenous administration of tissue plasminogen activator within 4.5 h of symptom onset is presently the 'golden rule' for treating acute ischemic stroke. However, many patients miss the time window and others reject this treatment due to a long list of contraindications. Mechanical embolectomy has recently progressed as a potential alternative for treating patients beyond the time window for IV thrombolysis. In this paper, recent progress in mechanical embolectomy, angioplasty, and stenting in acute stroke is reviewed. Despite worries concerning the long-term clinical outcomes and increased risk of intracranial hemorrhage, favorable clinical outcomes may be achieved after mechanical embolectomy in carefully selected patients even 4.5 h after stroke onset. Potential steps should be prepared and attempted in these patients whose opportunity for recovery will elapse in a flash.

CT perfusion imaging in acute stroke

Computed tomographic perfusion (CTP) imaging is an advanced modality that provides important information about capillary-level hemodynamics of the brain parenchyma. CTP can aid in diagnosis, management, and prognosis of acute stroke patients by clarifying acute cerebral physiology and hemodynamic status, including distinguishing severely hypoperfused but potentially salvageable tissue from both tissue likely to be irreversibly infarcted ("core") and hypoperfused but metabolically stable tissue ("benign oligemia"). A qualitative estimate of the presence and degree of ischemia is typically required for guiding clinical management. Radiation dose issues with CTP imaging, a topic of much current concern, are also addressed in this review.

Ischaemic stroke: a thrombo-inflammatory disease?

Ischaemic stroke is a leading cause of death and disability worldwide. The complex cellular interactions leading from thromboembolic vessel occlusion to infarct development within the brain parenchyma in acute stroke are poorly understood, which translates into only one approved effective treatment, thrombolysis. Importantly, however, patients can develop progressive stroke despite reperfusion of previously occluded major intracranial arteries, a process referred to as 'reperfusion injury' which can be reproduced in the mouse model of transient middle cerebral artery occlusion (tMCAO). Although pathological platelet and coagulant activity have long been recognized to be involved in the initiation of ischaemic stroke, their contribution to infarct maturation remained elusive. Experimental evidence now suggests that early platelet adhesion/activation mechanisms involving the von Willebrand factor (vWF) receptor glycoprotein (GP) Ib, its ligand vWF, and the collagen receptor GPVI are critical pathogenic factors in infarct development following tMCAO, whereas platelet aggregation through GPIIb/IIIa is not. Further experimental work indicates that these pathways in conjunction with coagulation factor XII (FXII)-driven processes orchestrate a 'thrombo-inflammatory' cascade in acute stroke that results in infarct growth. This review summarizes these recent developments and briefly discusses their potential clinical impact.

Improving reperfusion therapy for acute ischaemic stroke

BACKGROUND

The first generation of clinical reperfusion treatment, intravenous (IV) fibrinolysis with tissue plasminogen activator (tPA), was a transformative breakthrough in stroke care, but is far from ideal.

OBJECTIVES

TO survey emerging strategies to increase the efficacy and safety of cerebral reperfusion therapy.

METHODS

Narrative review.

RESULTS AND CONCLUSIONS

Innovative IV pharmacologic reperfusion strategies include: extending IV tPA use to patients with mild deficits; developing novel fibrinolytic agents (tenecteplase, desmetolplase, plasmin); using ultrasound to enhance enzymatic fibrinolysis; combination clot lysis therapies (fibrinolytics with GPIIb/IIIa agents or direct thrombin inhibitors); co-administration of MMP-9 inhibitors to deter haemorrhagic transformation; and prehospital neuroprotection to support threatened tissues until reperfusion. Endovascular recanalisation strategies are rapidly evolving, and include intra-arterial fibrinolysis, mechanical clot retrieval, suction thrombectomy, and primary stenting. Combined approaches appear especially promising, using IV fibrinolysis to rapidly initiate reperfusion, mechanical endovascular treatment to debulk large, proximal thrombi, and intra-arterial (IA) fibrinolysis to clear residual distal thrombus elements and emboli.

Pharmacological and non-pharmacological recanalization strategies in acute ischemic stroke

According to the guidelines of the European Stroke Organization (ESO) and the American Stroke Association (ASA), acute stroke patients should be managed at stroke units that include well organized pre- and in-hospital care. In ischemic stroke the restoration of blood flow has to occur within a limited time window that is accomplished by fibrinolytic therapy. Newer generation thrombolytic agents (alteplase, pro-urokinase, reteplase, tenecteplase, desmoteplase) have shorter half-life and are more fibrin-specific. Only alteplase has Food and Drug Administration (FDA) approval for the treatment of acute stroke (1996). The National Institute of Neurological Disorders and Stroke (NINDS) trial proved that alteplase was effective in all subtypes of ischemic strokes within the first 3 h. In the European cooperative acute stroke study III trial, intravenous (IV) alteplase therapy was found to be safe and effective (with some restrictions) if applied within the first 3-4.5 h. In middle cerebral artery (MCA) occlusion additional transcranial Doppler insonication may improve the breakdown of the blood clot. According to the ESO and ASA guidelines, intra-arterial (IA) thrombolysis is an option for recanalization within 6 h of MCA occlusion. Further trials on the IA therapy are needed, as previous studies have involved relatively small number of patients (compared to IV trials) and the optimal IA dose of alteplase has not been determined (20-30 mg is used most commonly in 2 h). Patients undergoing combined (IV + IA) thrombolysis had significantly better outcome than the placebo group or the IV therapy alone in the NINDS trial (Interventional Management of Stroke trials). If thrombolysis fails or it is contraindicated, mechanical devices [e.g., mechanical embolus removal in cerebral ischemia (MERCI)- approved in 2004] might be used to remove the occluding clot. Stenting can also be an option in case of acute internal carotid artery occlusion in the future. An intra-aortic balloon was used to increase the collateral blood flow in the Safety and Efficacy of NeuroFlo(™) Technology in Ischemic Stroke trial (results are under evaluation). Currently, there is no approved effective neuroprotective drug.

Antithrombin III associated with fibrinogen predicts the risk of cerebral ischemic stroke

BACKGROUND AND PURPOSE

The purpose of this study is to examine the feasibility of developing plasma predictive value biomarkers of cerebral ischemic stroke before imaging evidence is acquired.

METHODS

Blood samples were obtained from 198 patients who attended our neurology department as emergencies - with symptoms of vertigo, numbness, limb weakness, etc. - within 4.5 h of symptom onset, and before imaging evidence was obtained and medical treatment. After the final diagnosis was made by MRI/DWI/MRA or CTA in the following 24-72 h, the above cases were divided into two groups: stroke group and non-stroke group according to the imaging results. The levels of baseline plasma antithrombin III (AT-III), thrombin-antithrombin III (TAT), fibrinogen, D-dimer and high-sensitivity C-reactive protein (hsCRP) in the two groups were assayed.

RESULTS

The level of the baseline AT-III in the stroke group was 118.07±26.22%, which was lower than that of the non-stroke group (283.83±38.39%). The levels of TAT, fibrinogen, hsCRP were 7.24±2.28 μg/L, 5.49±0.98 g/L, and 2.17±1.07 mg/L, respectively, which were higher than those of the non-stroke group (2.53±1.23 μg/L, 3.35±0.50 g/L, 1.82±0.67 mg/L). All the P-values were less than 0.001. The D-dimer level was 322.57±60.34 μg/L, which was slightly higher than that of the non-stroke group (305.76±49.52 μg/L), but the P-value was 0.667. The sensitivities of AT-III, TAT, fibrinogen, D-dimer and hsCRP for predicting ischemic stroke tendency were 97.37%, 96.05%, 3.29%, 7.89%, but the specificity was 93.62%, 82.61%, 100% and 100%, respectively, and all the P-values were less than 0.001. High levels of D-dimer and hsCRP were mainly seen in the few cases with severe large-vessel infarction.

CONCLUSIONS

Clinical manifestations of acute focal neurological deficits were associated with plasma AT-III and fibrinogen. These tests might help the risk assessment of acute cerebral ischemic stroke and/or TIA with infarction tendency in the superacute stage before positive imaging evidence is obtained.

Thrombolytic therapy for acute ischemic stroke beyond three hours

BACKGROUND

Ischemic cerebrovascular accidents remain a leading cause of morbidity and mortality. Thrombolytic therapy for acute ischemic stroke within 3h of symptom onset of highly select patients has been advocated by some groups since 1995, but trials have yielded inconsistent outcomes. One recent trial demonstrated significant improvement when the therapeutic window was extended to 4.5h.

CLINICAL QUESTION

Does the intravenous systemic administration of tPA within 4.5h to select patients with acute ischemic stroke improve functional outcomes?

EVIDENCE REVIEW

All randomized controlled trials enrolling patients within 4.5h were identified, in addition to a meta-analysis of these trial data.

RESULTS

The National Institute of Neurological Disorders and Stroke (NINDS) and European Cooperative Acute Stroke Study III (ECASS III) clinical trials demonstrated significantly improved outcomes at 3 months, with increased rates of intracranial hemorrhage, whereas ECASS II and the Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) study showed increased hemorrhagic complications without improving outcomes. Meta-analysis of trial data from all ECASS trials, NINDS, and ATLANTIS suggest that thrombolysis within 4.5h improves functional outcomes.

CONCLUSION

Ischemic stroke tPA treatment within 4.5h seems to improve functional outcomes and increases symptomatic intracranial hemorrhage rates without significantly increasing mortality.

Taking a light approach to treating acute ischemic stroke patients: transcranial near-infrared laser therapy translational science

Transcranial near-infrared laser therapy (NILT) has been investigated as a novel neuroprotective treatment for acute ischemic stroke (AIS), for approximately 10 years. Two clinical trials, NeuroThera Effectiveness and Safety Trial (NEST)-1 and NEST-2, have evaluated the use of NILT to promote clinical recovery in patients with AIS. This review covers preclinical, translational, and clinical studies documented during the period 1997-2010. The primary aim of this article is to detail the development profile of NILT to treat AIS. Secondly, insight into possible mechanisms involved in light therapy will be presented. Lastly, possible new directions that should be considered to improve the efficacy profile of NILT in AIS patients will be discussed. The use of NILT was advanced to clinical trials based upon extensive translational research using multiple species. NILT, which may promote functional and behavioral recovery via a mitochondrial mechanism and by enhancing cerebral blood flow, may eventually be established as an Food and Drug Administration (FDA)-approved treatment for stroke. The NEST-3 trial, which is the pivotal trial for FDA approval, should incorporate hypotheses derived from translational studies to ensure efficacy in patients. Future NILT studies should consider administration of a thrombolytic to enhance cerebral reperfusion alongside NILT neuroprotection.

Graphic reanalysis of the two NINDS-tPA trials confirms substantial treatment benefit

BACKGROUND AND PURPOSE

Multiple statistical analyses of the 2 NINDS-tPA trials have confirmed study findings of benefit of fibrinolytic therapy. A recent graphic analysis departed from best practices in the visual display of quantitative information by failing to take into account the skewed functional importance of NIH Stroke Scale raw scores and by scaling change axes at up to 20 times the range achievable by individual patients.

METHODS

Using the publicly available datasets of the 2 NINDS-tPA trials, we generated a variety of figures appropriate to the characteristics of acute stroke trial data.

RESULTS

A diverse array of figures all visually delineated substantial benefits of fibrinolytic therapy, including: bar charts of normalized gain and loss; stacked bar, bar, and matrix plots of clinically relevant ordinal ranks; a time series stacked line plot of continuous scale disability weights; and line plot, bubble chart, and person icon array graphs of joint outcome table analysis. The achievable change figure showed substantially greater improvement among tPA than placebo patients, median 66.7% (interquartile range, 0 to 92.0) versus 50.0% (interquartile range, -7.1 to 80.0), P=0.003.

CONCLUSIONS

On average, under 3 hour patients treated with tPA recovered two-thirds while placebo patients improved only half of the way toward fully normal. Graphical analyses of the 2 NINDS-tPA trials, when performed according to best practices, is a useful means of conveying details about patient response to therapy not fully delineated by summary statistics, and confirms a valuable treatment benefit of under 3 hour fibrinolytic therapy in acute stroke.

Trends in thrombolytic use for ischemic stroke in the United States

BACKGROUND

Although recombinant tissue plasminogen activator (tPA) improves outcomes from ischemic stroke, prior studies have found low rates of administration. Recent guidelines and regulatory agencies have advocated for increased tPA administration in appropriate patients, but it is unclear how many patients actually receive tPA.

OBJECTIVE

To determine whether national rates of tPA use for ischemic stroke have increased over time.

METHODS

We identified all patients with a primary diagnosis of ischemic stroke from years 2001 to 2006 in the National Hospital Discharge Survey (NHDS), a nationally representative sample of inpatient hospitalizations, and searched for procedure codes for intravenous thrombolytic administration. Clinical and demographic factors were obtained from the survey and multivariable logistic regression used to identify independent predictors associated with thrombolytic use.

RESULTS

Among the 22,842 patients hospitalized with ischemic stroke, tPA administration rates increased from 0.87% in 2001 to 2.40% in 2006 (P < 0.001 for trend). Older patients were less likely to receive tPA (adjusted odds ratio [OR] and 95% confidence interval [CI]; 0.4 [0.3-0.6] for patients ≥80 years vs. <60 years), as were African American patients (0.4 [0.3-0.7]). Larger hospitals were more likely to administer tPA (3.3 [2.0-5.6] in hospitals with at least 300 beds compared to those with 6-99 beds).

CONCLUSIONS

Although tPA administration for ischemic stroke has increased nationally in recent years, the overall rate of use remains very low. Larger hospitals were more likely to administer tPA. Further efforts to improve appropriate administration of tPA should be encouraged, particularly as the acceptable time-window for using tPA widens.

Glial growth factor 2 promotes functional recovery with treatment initiated up to 7 days after permanent focal ischemic stroke

Neuregulins are a family of growth factors essential for normal cardiac and nervous system development. The EGF-like domain of neuregulins contains the active site which binds and activates signaling cascades through ErbB receptors. A neuregulin-1 gene EGF-like fragment demonstrated neuroprotection in the transient middle cerebral artery occlusion (MCAO) stroke model and drastically reduced infarct volume (Xu et al., 2004). Here we use a permanent MCAO rat model to initially compare two products of the neuregulin-1 gene and also assess levels of recovery with acute versus delayed time to treatment. In the initial study full-length glial growth factor 2 (GGF2) and an EGF-like domain fragment were compared with acute intravenous delivery. In a second study GGF2 only was delivered starting at 24h, 3 days or 7 days after permanent ischemia was induced. In both studies daily intravenous administration continued for 10 days. Recovery of neurological function was assessed using limb placing and body swing tests. GGF2 had similar functional improvements compared to the EGF-like domain fragment at equimolar doses, and a higher dose of GGF2 demonstrated more robust functional improvements compared to a lower dose. GGF2 improved sensorimotor recovery with all treatment paradigms, even enhancing recovery of function with a delay of 7 days to treatment. Histological assessments did not show any associated reduction in infarct volume at either 48 h or 21 days post-ischemic event. Neurorestorative effects of this kind are of great potential clinical importance, given the difficulty of delivering neuroprotective therapies within a short time after an ischemic event in human patients. If confirmed by additional work including additional data on mechanism(s) of improved outcome with verification in other stroke models, one can make a compelling case to bring GGF2 to clinical trials as a neurorestorative approach to improving outcome following stroke injury.

Making a Case for Acute Ischemic Stroke

Stroke is the third leading cause of death in the United States and the number one cause of adult long-term disability. Disability in stroke survivors includes hemiparesis, aphasia, inability to walk without assistance, dependence on others for activities of daily living, depression, and institutionalization. Immediate recognition of acute ischemic stroke (AIS) signs and symptoms is required because many treatment options are time sensitive. Hospital transport via activation of 911 and emergency medical services (EMSs) removes delays to urgent diagnosis and intervention. Intravenous (IV) recombinant tissue plasminogen (rt-PA) is a time-sensitive reperfusion strategy. The American Heart Association (AHA) and American Stroke Association (ASA) recently revised recommendations that the time window for IV rt-PA be expanded from 3 hours to 4.5 hours after symptom onset in patients with mild to moderate stroke. Supportive therapies include crystalloid IV solutions, adequate oxygenation, and normothermia. Best rest is desired along with oxygen supplementation. Avoidance of fever is paramount since fever can contribute to negative outcomes. It is the purpose of this article to review risk factors, stroke symptoms, epidemiology, and current drug therapy of AIS. Standards of care will be reviewed.

Acute ischemic stroke update

Stroke is the third most common cause of death in the United States and is the number one cause of long-term disability. Legislative mandates, largely the result of the American Heart Association, American Stroke Association, and Brain Attack Coalition working cooperatively, have resulted in nationwide standardization of care for patients who experience a stroke. Transport to a skilled facility that can provide optimal care, including immediate treatment to halt or reverse the damage caused by stroke, must occur swiftly. Admission to a certified stroke center is recommended for improving outcomes. Most strokes are ischemic in nature. Acute ischemic stroke is a heterogeneous group of vascular diseases, which makes targeted treatment challenging. To provide a thorough review of the literature since the 2007 acute ischemic stroke guidelines were developed, we performed a search of the MEDLINE database (January 1, 2004-July 1, 2009) for relevant English-language studies. Results (through July 1, 2009) from clinical trials included in the Internet Stroke Center registry were also accessed. Results from several pivotal studies have contributed to our knowledge of stroke. Additional data support the efficacy and safety of intravenous alteplase, the standard of care for acute ischemic stroke since 1995. Due to these study results, the American Stroke Association changed its recommendation to extend the time window for administration of intravenous alteplase from within 3 hours to 4.5 hours of symptom onset; this recommendation enables many more patients to receive the drug. Other findings included clinically useful biomarkers, the role of inflammation and infection, an expanded role for placement of intracranial stents, a reduced role for urgent carotid endarterectomy, alternative treatments for large-vessel disease, identification of nontraditional risk factors, including risk factors for women, and newly published pediatric stroke guidelines. In addition, new devices for thrombolectomy are being developed, and neuroprotective therapies such as the use of magnesium, statins, and induced hypothermia are being explored. As treatment interventions become more clearly defined in special subgroups of patients, outcomes in patients with acute ischemic stroke will likely continue to improve.

Time to treatment with intravenous alteplase and outcome in stroke: an updated pooled analysis of ECASS, ATLANTIS, NINDS, and EPITHET trials

BACKGROUND

Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to treatment with intravenous rt-PA (alteplase) on therapeutic benefit and clinical risk by adding recent trial data to the analysis.

METHODS

We added data from ECASS III (821 patients) and EPITHET (100 patients) to a pool of common data elements from six other trials of alteplase for acute stroke (2775 patients). We used multivariate logistic regression to assess the relation of stroke onset to start of treatment (OTT) with treatment on favourable 3-month outcome (defined as modified Rankin score 0-1), mortality, and occurrence and outcome of clinically relevant parenchymal haemorrhage. The presence of an arterial occlusion was inferred from the patient's symptoms and absence of haemorrhage or other causes of ischaemic stroke. Vascular imaging was not a requirement in the trials. All patients with confirmed OTT within 360 min were included in the analysis.

FINDINGS

Treatment was started within 360 min of stroke onset in 3670 patients randomly allocated to alteplase (n=1850) or to placebo (n=1820). Odds of a favourable 3-month outcome increased as OTT decreased (p=0.0269) and no benefit of alteplase treatment was seen after around 270 min. Adjusted odds of a favourable 3-month outcome were 2.55 (95% CI 1.44-4.52) for 0-90 min, 1.64 (1.12-2.40) for 91-180 min, 1.34 (1.06-1.68) for 181-270 min, and 1.22 (0.92-1.61) for 271-360 min in favour of the alteplase group. Large parenchymal haemorrhage was seen in 96 (5.2%) of 1850 patients assigned to alteplase and 18 (1.0%) of 1820 controls, with no clear relation to OTT (p=0.4140). Adjusted odds of mortality increased with OTT (p=0.0444) and were 0.78 (0.41-1.48) for 0-90 min, 1.13 (0.70-1.82) for 91-180 min, 1.22 (0.87-1.71) for 181-270 min, and 1.49 (1.00-2.21) for 271-360 min.

INTERPRETATION

Patients with ischaemic stroke selected by clinical symptoms and CT benefit from intravenous alteplase when treated up to 4.5 h. To increase benefit to a maximum, every effort should be taken to shorten delay in initiation of treatment. Beyond 4.5 h, risk might outweigh benefit.

FUNDING

None.

Improving the reliability of stroke disability grading in clinical trials and clinical practice: the Rankin Focused Assessment (RFA)

BACKGROUND AND PURPOSE

The modified Rankin Scale rates global disability after stroke and is the most comprehensive and widely used primary outcome measure in acute stroke trials. However, substantial interobserver variability in modified Rankin Scale scoring has been reported. This study sought to develop and validate a short, practicable structured assessment that would enhance interrater reliability.

METHODS

The Rankin Focused Assessment was developed by selecting and refining elements from prior instruments. The Rankin Focused Assessment takes 3 to 5 minutes to apply and provides clear, operationalized criteria to distinguish the 7 assignable global disability levels. The Rankin Focused Assessment was prospectively validated 3 months poststroke among 50 consecutive patients enrolled in the Phase 3 National Institutes of Health Field Administration of Stroke Therapy-Magnesium (FAST-MAG) Trial.

RESULTS

Among the 50 patients, mean age was 71.5 years (range, 43 to 93 years), 48% were female, and stroke subtype was hemorrhagic in 24%. At Day 90, 43 patients were alive and 7 had died. The modified Rankin Scale median was 2.0 and mean was 2.8. When pairs of 14 raters assessed all enrolled patients, the percent agreement was 94%, the weighted kappa was 0.99 (95% CI, 0.99 to 1.0), and the unweighted kappa was 0.93 (95% CI, 0.85 to 1.00). Among the 43 surviving patients, the percent agreement was 93%, the weighted kappa was 0.99 (0.98 to 1.0), and the unweighted kappa was 0.91 (0.82 to 1.00).

CONCLUSIONS

The Rankin Focused Assessment yields high interrater reliability in the grading of final global disability among consecutive patients with stroke participating in a randomized clinical trial. The Rankin Focused Assessment is brief and practical for use in multicenter clinical trials and quality improvement activities.