Urgent therapy for stroke. Part I. Pilot study of tissue plasminogen activator administered within 90 minutes

Optimal dose for stroke thrombolysis in Asians: low dose may have similar safety and efficacy as standard dose

BACKGROUND

Although intravenous tissue-type plasminogen activator (t-PA) at a standard dose of 0.9 mg kg(-1) is effective for patients with acute ischemic stroke, concerns have been raised regarding Asians.

OBJECTIVES

To compare the safety and efficacy between low and standard doses for stroke thrombolysis.

PATIENTS/METHODS

Consecutive patients receiving t-PA treatment were recruited according to the prespecified dosing policy from two medical centers in Taiwan: low dose (0.7 mg kg(-1) ) at National Cheng Kung University Hospital (NCKUH) from August 2006 to June 2009, or standard dose (0.9 mg kg(-1) ) at NCKUH from July 2009 to December 2010 and at Changhua Christian Hospital from May 2008 to December 2010. The primary safety outcome was the occurrence of symptomatic intracerebral hemorrhage (SICH). The secondary efficacy outcome was the proportion of patients with a modified Rankin Scale (mRS) grade of ≤ 1 at 3 months.

RESULTS

From August 2006 to December 2010, 261 patients were recruited, of whom 105 and 156 received low and standard doses, respectively. The occurrence of SICH was non-significantly lower in the standard-dose group than in the low-dose group (2.6% vs. 4.8%, respectively; P = 0.34). The favorable outcome of mRS grade of ≤ 1 at 3 months was similar (38.4% and 41.1%, respectively; P = 0.676). A review of other case series of low vs. standard doses in Asians also showed similar safety and efficacy.

CONCLUSION

Our study, as well as other case series on Asians, revealed that standard-dose thrombolysis for acute ischemic stroke in an Asian population carries no increased risk of symptomatic intracerebral hemorrhage when compared with the low dose.

Medical therapy for ischemic stroke: review of intravenous and intra-arterial treatment options

BACKGROUND

Thrombolytic therapy is of proven and substantial benefit for select patients with acute cerebral ischemia. Diagnostic options and medical treatment options for acute stroke ischemia have undergone enormous changes in the past decades. Whereas initially stroke treatment was reduced to prevention, management of symptoms, and rehabilitation, nowadays a multitude of different fibrinolytic drugs are available. The wide availability of computed tomography in the late 1980s made thrombolysis a real therapeutic option because it allowed a fast and accurate differentiation between ischemic and hemorrhagic stroke.

METHODS

This study reviews these developments and how they have shaped our current use and understanding of thrombolytics in the treatment of acute ischemic stroke.

RESULTS

Patient selection remains a central aspect of thrombolytic treatment, and to date, the use of different fibrinolytics has been studied in over 20 large randomized trials for different clinical settings, time windows, and routes of administration. These studies included over 7000 patients, and led to our current understanding of the use of thrombolysis in acute stroke.

CONCLUSIONS

Intravenous fibrinolytic therapy within the first 3 hours of ischemic stroke onset offers substantial benefits for virtually all patients with potentially disabling deficits. In the 3- to 4.5-hour treatment window, intravenous fibrinolytic therapy has been shown to offer moderate net benefits when applied to all patients with potentially disabling deficits. Intra-arterial fibrinolytic therapy in the 3- to 6-hour window offers moderate net benefits when applied to all patients with potentially disabling deficits and large-artery cerebral thrombotic occlusions.

Intravenous thrombolysis for acute ischemic stroke in Asia

Data regarding thrombolysis for acute ischemic stroke in Asia are scarce and only a small percentage of patients are thrombolysed. Clinical trials that led to the recommended dose of intravenously administered tissue plasminogen activator (IV-tPA) included predominantly Caucasian patients. However, the single-arm case-controlled observational studies in Japanese patients suggested the clinical efficacy and safety of low-dose IV-tPA (0.6 mg/kg bodyweight; maximum 60 mg) comparable with standard dose (0.9 mg/kg bodyweight; maximum 90 mg). There has been no randomized clinical trial for determining the dose, efficacy or safety of IV-tPA in Asia. Accordingly, the dose of IV-tPA in Asia remains controversial. Reduced treatment cost, lower symptomatic intracerebral hemorrhage risk and comparable efficacy encouraged many Asian centers to adopt low-dose or even variable-dose IV-tPA regimens. We present the current status of thrombolysis for acute ischemic stroke in Asia.

A higher body temperature is associated with haemorrhagic transformation in patients with acute stroke untreated with recombinant tissue-type plasminogen activator (rtPA)

Higher body temperature is a prognostic factor of poor outcome in acute stroke. Our aim was to study the relationship between body temperature, HT (haemorrhagic transformation) and biomarkers of BBB (blood-brain barrier) damage in patients with acute ischaemic stroke untreated with rtPA (recombinant tissue-type plasminogen activator). We studied 229 patients with ischaemic stroke <12 h from symptom onset. Body temperature was determined at admission and every 6 h during the first 3 days. HT was evaluated according to ECASS II (second European Co-operative Acute Stroke Study) criteria in a multimodal MRI (magnetic resonance imaging) at 72 h. We found that 55 patients (34.1%) showed HT. HT was associated with cardioembolic stroke (64.2% against 23.0%; P<0.0001), higher body temperature during the first 24 h (36.9°C compared with 36.5°C; P<0.0001), more severe stroke [NIHSS (National Institutes of Health Stroke Scale) score, 14 (9-20) against 10 (7-15); P=0.002], and greater DWI (diffusion-weighted imaging) lesion volume at admission (23.2 cc compared with 13.2 cc; P<0.0001). Plasma MMP-9 (matrix metalloproteinase 9) (187.3 ng/ml compared with 44.2 ng/ml; P<0.0001) and cFn (cellular fibronectin) levels (16.3 μg/ml compared with 7.1 μg/ml; P=0.001) were higher in patients with HT. Body temperature within the first 24 h was independently associated with HT {OR (odds ratio), 7.3 [95% CI (confidence interval), 2.4-22.6]; P<0.0001} after adjustment for cardioembolic stroke subtype, baseline NIHSS score and DWI lesion volume. This effect remained unchanged after controlling for MMP-9 and cFn. In conclusion, high body temperature within the first 24 h after ischaemic stroke is a risk factor for HT in patients untreated with rtPA. This effect is independent of some biological signatures of BBB damage.

Primary outcomes for resuscitation science studies: a consensus statement from the American Heart Association

BACKGROUND AND PURPOSE

The guidelines presented in this consensus statement are intended to serve researchers, clinicians, reviewers, and regulators in the selection of the most appropriate primary outcome for a clinical trial of cardiac arrest therapies. The American Heart Association guidelines for the treatment of cardiac arrest depend on high-quality clinical trials, which depend on the selection of a meaningful primary outcome. Because this selection process has been the subject of much controversy, a consensus conference was convened with national and international experts, the National Institutes of Health, and the US Food and Drug Administration.

METHODS

The Research Working Group of the American Heart Association Emergency Cardiovascular Care Committee nominated subject leaders, conference attendees, and writing group members on the basis of their expertise in clinical trials and a diverse perspective of cardiovascular and neurological outcomes (see the online-only Data Supplement). Approval was obtained from the Emergency Cardiovascular Care Committee and the American Heart Association Manuscript Oversight Committee. Preconference position papers were circulated for review; the conference was held; and postconference consensus documents were circulated for review and comments were invited from experts, conference attendees, and writing group members. Discussions focused on (1) when after cardiac arrest the measurement time point should occur; (2) what cardiovascular, neurological, and other physiology should be assessed; and (3) the costs associated with various end points. The final document underwent extensive revision and peer review by the Emergency Cardiovascular Care Committee, the American Heart Association Science Advisory and Coordinating Committee, and oversight committees.

RESULTS

There was consensus that no single primary outcome is appropriate for all studies of cardiac arrest. The best outcome measure is the pairing of a time point and physiological condition that will best answer the question under study. Conference participants were asked to assign an outcome to each of 4 hypothetical cases; however, there was not complete agreement on an ideal outcome measure even after extensive discussion and debate. There was general consensus that it is appropriate for earlier studies to enroll fewer patients and to use earlier time points such as return of spontaneous circulation, simple "alive versus dead," hospital mortality, or a hemodynamic parameter. For larger studies, a longer time point after arrest should be considered because neurological assessments fluctuate for at least 90 days after arrest. For large trials designed to have a major impact on public health policy, longer-term end points such as 90 days coupled with neurocognitive and quality-of-life assessments should be considered, as should the additional costs of this approach. For studies that will require regulatory oversight, early discussions with regulatory agencies are strongly advised. For neurological assessment of post-cardiac arrest patients, researchers may wish to use the Cerebral Performance Categories or modified Rankin Scale for global outcomes.

CONCLUSIONS

Although there is no single recommended outcome measure for trials of cardiac arrest care, the simple Cerebral Performance Categories or modified Rankin Scale after 90 days provides a reasonable outcome parameter for many trials. The lack of an easy-to-administer neurological functional outcome measure that is well validated in post-cardiac arrest patients is a major limitation to the field and should be a high priority for future development.

Pharmaceutical sponsorship bias influences thrombolytic literature in acute ischemic stroke

BACKGROUND

The efficacy of thrombolytic therapy for acute ischemic stroke remains controversial in emergency medicine and has not been fully endorsed by either the American College of Emergency Physicians or the American Academy of emergency medicine. A growing recognition exists of the influence of pharmaceutical sponsorship on the reported findings of published clinical trials. Sponsorship bias has been suggested as a potential criticism of the literature and guidelines favoring thrombolytic therapy.

OBJECTIVE

The objective of this study is to review the most influential literature regarding thrombolytic therapy for acute ischemic stroke and document the presence or absence of pharmaceutical sponsorship.

METHODS

A publication-citation analysis was performed to identify the most frequently cited articles pertaining to thrombolytic therapy for acute ischemic stroke. Identified articles were reviewed for disclosures of pharmaceutical funding.

RESULTS

Of the 20 most-cited articles pertaining to thrombolytic therapy for acute stroke, 17 (85%) disclosed pharmaceutical sponsorship. These disclosures range from general sponsorship to direct employment of authors by pharmaceutical companies.

CONCLUSION

An overwhelming predominance of the most influential literature regarding thrombolytic therapy for acute ischemic stroke is susceptible to sponsorship bias. This potential bias may provide a basis for physician concern regarding the efficacy and safety of thrombolytic therapy. Further, large, independent, placebo-controlled studies may be required to guide therapy and professional guidelines definitively for acute ischemic stroke.

Outcome of intravenous thrombolysis in stroke patients weighing over 100 kg

BACKGROUND

Intravenous thrombolysis with alteplase for ischemic stroke is fixed at a maximal dose of 90 mg for safety reasons. Little is known about the clinical outcomes of stroke patients weighing >100 kg, who may benefit less from thrombolysis due to this dose limitation.

METHODS

Prospective data on 1,479 consecutive stroke patients treated with intravenous alteplase in six Swiss stroke units were analyzed. Presenting characteristics and the frequency of favorable outcomes, defined as a modified Rankin scale (mRS) score of 0 or 1, a good outcome (mRS score 0-2), mortality and symptomatic intracranial hemorrhage (SICH) were compared between patients weighing >100 kg and those weighing ≤100 kg.

RESULTS

Compared to their counterparts (n = 1,384, mean body weight 73 kg), patients weighing >100 kg (n = 95, mean body weight 108 kg) were younger (61 vs. 67 years, p < 0.001), were more frequently males (83 vs. 60%, p < 0.001) and more frequently suffered from diabetes mellitus (30 vs. 13%, p < 0.001). As compared with patients weighing ≤100 kg, patients weighing >100 kg had similar rates of favorable outcomes (45 vs. 48%, p = 0.656), good outcomes (58 vs. 64%, p = 0.270) and mortality (17 vs. 12%, p = 0.196), and SICH risk (1 vs. 5%, p = 0.182). After multivariable adjustment, body weight >100 kg was strongly associated with mortality (p = 0.007) and poor outcome (p = 0.007).

CONCLUSION

Our data do not suggest a reduced likehood of favorable outcomes in patients weighing >100 kg treated with the current dose regimen. The association of body weight >100 kg with mortality and poor outcome, however, demands further large-scale studies to replicate our findings and to explore the underlying mechanisms.

Intravenous thrombolytics for ischemic stroke

For many decades, intravenous (IV) thrombolytics have been delivered to treat acute thrombosis. Although these medications were originally effective for coronary thrombosis, their mechanisms have proven beneficial for many other disease processes, including ischemic stroke. Treatment paradigms for acute ischemic stroke have largely followed those of cardiology. Specifically, the aim has been to recanalize the occluded artery and to restore perfusion to the brain that remains salvageable. To that end, rapid clot lysis was sought using thrombolytic medicines already proven effective in the coronary arteries. IV-thrombolysis for ischemic stroke began its widespread adoption in the late 1990s after the publication of the National Institute of Neurological Disorders and Stroke study. Since that time, other promising IV-thrombolytics have been developed and tested in human trials, but as of yet, none have been proven better than a placebo. Adjunctive treatments are also being evaluated. The challenge remains balancing reperfusion and salvaging brain tissue with the potential risks of brain hemorrhage.

Role of tissue plasminogen activator in acute ischemic stroke

OBJECTIVE

To evaluate the literature regarding the use of intravenous tissue plasminogen activator (tPA) in the treatment of acute ischemic stroke, focusing on the appropriate usage criteria and administration time window.

DATA SOURCES

A PubMed and MEDLINE search was performed (1990-November 2010) using the key words alteplase, tissue plasminogen activator, thrombolytic, ischemic stroke, and cerebrovascular accident.

STUDY SELECTION AND DATA EXTRACTION

Clinical trials published in English were evaluated and relevant primary literature evaluating the use of tPA in acute ischemic stroke was included.

DATA SYNTHESIS

The NINDS (National Institute of Neurological Disorders and Stroke) trial revealed clinical efficacy of tPA in the treatment of acute ischemic stroke when administered within 3 hours of stroke symptom onset and served as the foundation for the American Heart Association/American Stroke Association (AHA/ASA) acute ischemic stroke guideline recommendations. The ECASS (European Cooperative Acute Stroke Study) I, ECASS II, and ATLANTIS (Alteplase Thrombolysis for Acute Noninterventional Therapy in Ischemic Stroke), part A and B, trials each assessed the efficacy of tPA when administered beyond 3 hours of ischemic stroke onset, but the results of each trial did not support its use beyond 3 hours. The ECASS III trial showed clinical efficacy of tPA when administered up to 4.5 hours. The SITS-MOST (Safe Implementation of Thrombolysis in Stroke-Monitoring Study) and SITS-ISTR (Safe Implementation of Thrombolysis in Stroke International Stroke Thrombolysis Register) registries evaluated the safety and efficacy of tPA at both 3 and 4.5 hours and showed promising results. In 2009, the AHA/ASA stroke guidelines were updated to support the use of tPA in select patients up to 4.5 hours after symptom onset.

CONCLUSIONS

tPA is effective when administered up to 4.5 hours after ischemic stroke symptom onset in select patients. However, timely administration remains paramount to achievement of optimal therapeutic outcomes.

Intravenous Thrombolysis for Acute Ischaemic Stroke: Effective Blood Pressure Control Matters

In this Leading opinion we summarise the observational evidence endorsing current guidelines that advocate effective blood pressure control before and during an rtPA infusion and indicate that a more active blood pressure-lowering approach immediately after intravenous thrombolysis appears to be a promising therapeutic option that should be formerly evaluated in a randomised clinical trial setting. Acute ischaemic stroke is a highly treatable neuroemergency and the efficacy of the available treatment is not only related to the speed by which it is administered but also by the effective control of modifiable adverse outcome predictors including elevated blood pressure levels.

A large screening of angiogenesis biomarkers and their association with neurological outcome after ischemic stroke

BACKGROUND

The induction of angiogenesis after stroke may enhance neurorestorative processes. Our aim was to examine the endogenous angiogenesis balance and their association with long-term clinical outcome in ischemic stroke patients.

METHODS

A total of 109 stroke subjects were included in the study. Firstly, plasma samples were obtained from control subjects (n = 26) and tPA-treated stroke patients (n = 29) at baseline (within 3h of symptoms onset), 1, 2, 12, 24h after tPA treatment, at discharge and 3 months after the ischemic event. Angiogenic promoters (PDGF-AA, PDGF-BB, HGF, FGF, KGF, HB-EGF, TPO, VEGF, VEGFR-1, VEGFR-2 and SDF-1α) and inhibitors (endostatin, angiostatin, thrombospondin-1 and thrombospondin-2) were analyzed by Searchlight(®) technology or ELISA. Additionally, baseline and 24h endostatin plasma level was determined in a new set of stroke patients (n = 80). Clinical parameters (NIHSS, mRS, mortality and hemorrhagic transformation events) were assessed to evaluate outcome.

RESULTS

Baseline PDGF-BB, endostatin and thrombospondin-2 levels were higher in stroke patients than in controls (p < 0.05). A pro-angiogenic balance was associated with lower NIHSS scores and less intracranial hemorrhagic complications. Interestingly, a high baseline endostatin level was associated to long-term functional dependency (mRS > 2; p = 0.004). Finally, a baseline endostatin cut-off point of 184 ng/mL was an independent predictor of functional dependency at three months in the multiple logistic regression with an odds ratio of 8.9 (95% CI: 2.7-28.8; p = 0.0002).

CONCLUSIONS

Our results indicate that an early pro-angiogenic balance is associated with mild short-term neurological deficit, while an acute anti-angiogenesis status determined by high endostatin plasma level predicts a worse long-term functional outcome.

Intravenous Recombinant Tissue Plasminogen Activator Administered after 3 H following Onset of Ischaemic Stroke: A Metaanalysis

Objective

To assess the efficacy of intravenous recombinant tissue plasminogen activator administered after 3 h following onset of ischaemic stroke.

Background

Some recent data indicate that treatment with intravenous recombinant tissue plasminogen activator may be beneficial even when administered to ischaemic stroke patients beyond 3 h from symptom onset.

Methods

We searched the medical literature using the MEDLINE, BIOSIS, and Cochrane databases for pertinent publications from 1966 to 2008 using the keywords ‘alteplase’, ‘tissue plasminogen activator’, and ‘stroke’. Among the retrieved publications, we selected randomised controlled trials that administered recombinant tissue plasminogen activator during 3–6 h after symptom onset in patients with acute ischaemic stroke. We evaluated the effect of intravenous recombinant tissue plasminogen activator (compared with placebo) on the rate of good functional outcome (determined by modified Rankin Scale of 0–1) and mortality at three-months. A subset analysis was performed according to time of administration of intravenous recombinant tissue plasminogen activator (3–4·5 and 4·5–6 h). Odds ratios of individual trials were pooled using a random effects model.

Results

We analysed four randomised trials totaling 2104 patients (1053 control and 1051 recombinant tissue plasminogen activator-treated patients). Patients that received intravenous recombinant tissue plasminogen activator at 3–6 h following onset of symptoms had a significantly higher rate of favourable neurological outcome over the patients that received placebo (odds ratio 1·24, 95% confidence intervals 1·04–1·47, P=0·02). Treatment within the 3–4·5 time window was significantly associated with higher rate of favourable neurological outcome (OR 1·27, 95% confidence interval 1·01–1·60), but not for the 4·5–6 time window (OR 1·10, 95% confidence interval 0·75–1·51). There was no difference in mortality between patients that received intravenous recombinant tissue plasminogen activator than the patients that received pharmacologic placebo (OR 1·14, 95% confidence interval 0·76–1·70).

Conclusions

Treatment with intravenous recombinant tissue plasminogen activator from 3–4·5 h following symptom onset is associated with an increased rate of favourable outcome at 90-days in this analysis. Treatment with intravenous recombinant tissue plasminogen activator beyond 4·5 h did not show a benefit; however, improved patient selection is needed for future studies.

A Combined Treatment with Taurine and Intra-arterial Thrombolysis in an Embolic Model of Stroke in Rats: Increased Neuroprotective Efficacy and Extended Therapeutic Time Window

Combination treatment may target different pathophysiological events following cerebral ischemia thus enhancing the efficacy of treatment in thromboembolic stroke. Taurine confers a neuroprotective effect in the mechanical stroke model. This effect has not been assessed in an embolic stroke model. Here, we sought to evaluate the neuroprotective effect of taurine alone and in combination with thrombolytic therapy to investigate whether combined administration would extend the therapeutic time window without increasing the hemorrhagic transformation in a rat embolic stroke model. Rats were subjected to right embolic middle cerebral artery occlusion and then randomly assigned to the following groups: saline treatment alone at 4 h, urokinase, taurine treatment alone at 4, 6, or 8 h, and the combination of taurine and urokinase at 4, 6, or 8 h after the insult. Brain infarct volume, neurobehavioral outcome, regional cerebral blood flow, intracranial hemorrhage incidence were observed and evaluated. Posttreatment with taurine at 4 or 6 h, urokinase at 4 h or in combination at 4, 6, or 8 h significantly reduced infarct volume and improved neurobehavioral outcome. The combination treatment had better neurobehavioral outcome and smaller infarction volume than urokinase or taurine treatment alone. The clinical outcome correlated well with infarct volume. Together, the present study suggests that administration of taurine after stroke is neuroprotective, seemingly because it reduces the reperfusion damage of urokinase, leading to widen the therapeutic window for the thrombolytic effect of urokinase to 8 h. Thrombolysis can also enhance the neuroprotective effect of taurine. The reduction of inflammatory response, neuron death and inhibition of blood brain barrier (BBB) disruption may underlie the beneficial effects of combination of taurine and urokinase in the treatment of embolic stroke.

Bringing forward reperfusion with oxygenated blood perfusion beyond arterial occlusion during endovascular procedures in patients with acute ischemic stroke

BACKGROUND AND PURPOSE

High recanalization rates achieved with endovascular procedures are not always followed by the expected clinical improvement. These time-consuming procedures imply a delayed reperfusion despite the capacity of earlier intravascular microcatheter bypass to the ischemic tissue beyond the clot. We aimed to explore the safety and feasibility of MOB beyond the clot.

MATERIALS AND METHODS

We studied patients with stroke undergoing endovascular procedures. The timing of procedural steps was recorded. We then explored the safety and feasibility of repeated femoral artery MOB injections beyond the occlusion every time the clot was crossed in 17 patients. Pre- and postocclusion flow was continuously monitored with TCD.

RESULTS

We studied 60 patients (mean age, 70 ± 11 years; median NIHSS score, 20; IR, 18-21). Of them, 33 (55%) received IV-tPA before the endovascular procedure. The following arteries were occluded: the MCA (63.3%, n = 38) and the ICA (36.6%, n = 22). The TSO to arterial puncture was 193 ± 77 minutes. The occluding clot was successfully crossed with the microcatheter in 46 patients (76.6%; mean TSO, 228 ± 82 minutes). Recanalization was achieved in 44 patients (73.2%; mean TSO, 328 ± 144 minutes). Repeated MOB injections were performed in 17 patients. Patients with/without MOB presented with similar baseline characteristics. The median number of MOB injections was 2 (IR, 2-3), and the median injected blood volume was 40 mL (IR, 27.5-50). The mean time from first MOB to arterial recanalization was 136 ± 86 minutes. During MOB, a nonpulsatile flow appeared in previously nonvisible distal branches on TCD.

CONCLUSIONS

In this small series, oxygenated blood delivered through a microcatheter positioned distal to the site of occlusion was feasible and safe. Until final recanalization is achieved, MOB injections may generate intermittent reperfusion for up to 2 hours.

Osteopontin predicts long-term functional outcome among ischemic stroke patients

Osteopontin (OPN) is a multifunctional protein which has shown neuroprotective properties in animal models of cerebral ischemia. Nevertheless, its role in acute human stroke has not yet been established. Therefore, we aimed to determine human serum OPN level during acute ischemic stroke and its relationship with patient outcome. We measured OPN levels in 178 consecutive patients with a middle cerebral artery (MCA) occlusion who received fibrinolytic therapy and in 40 control subjects. OPN level was determined by an enzyme-linked immunosorbent assay (ELISA). Bad functional outcome was defined by modified Rankin Scale (mRS) score >2 at 3 months after stroke onset. A logistic regression analysis was performed to determine factors that could be independently associated with poor prognosis. OPN levels among stroke patients did not differ from the controls' OPN levels (16.65 vs. 17.83 ng/mL, p = 0.404). Interestingly, OPN level was increased among those patients who showed worse prognosis at 3 months (19.96 vs. 15.48 ng/mL, p = 0.040). In a logistic regression model, an OPN level >27.22 ng/mL was found to be an independent factor for a bad outcome (OR 5.01, 95% CI 1.60-15.72, p = 0.006) after adjusting for potential confounders. Those patients showing higher OPN levels before tPA administration displayed a worse prognosis compared to those with lower OPN levels. Further research is necessary to elucidate the role of OPN in ischemic stroke pathophysiology and validate OPN as a useful tool to predict long-term stroke outcome.

Reperfusion therapy for acute stroke improves outcome by decreasing neuroinflammation

Inflammation is a major step in the ischemic cascade, and proinflammatory cytokines, adhesion molecules and chemokines have been related to brain injury after stroke. To investigate if tissue plasminogen activator (tPA) treatment decreases the deleterious neuroinflammatory response that follows ischemic stroke. Our target population was 80 patients with ischemic stroke involving the middle cerebral artery (MCA) territory. Among them, 41 received tPA within 3 h of symptom onset according to National Institute of Neurological Disorders and Stroke recommendations and the remaining 39 were assessed prior to local approval of tPA. In all patients, blood samples were obtained at 12 and 24 h after symptom onset. Serum determinations of interleukin (IL)-6, inter-cellular adhesion molecule 1 (ICAM-1), IL-8 and tumor necrosis factor-alpha (TNF-α) were obtained by ELISA. National Institutes of Health Stroke Scale (NIHSS) and transcranial Doppler recordings (proximal/distal occlusion, p.o/d.o) were obtained at baseline and follow-up. No differences were found between the two groups in baseline NIHSS scores (tPA = 17 and control = 17; p = 0.38) or MCA status (tPA: p.o = 65.8%, control: p.o = 55.3%; p = 0.41). We found a lower level of mean IL-6 and IL-8 in the tPA treatment group: IL-6 (14.06 vs. 37.88 pg/ml, p = 0.001) and IL-8 (70.98 vs. 465 pg/ml, p < 0.001). No significant changes appeared for ICAM-1 and TNF-α. This biological response was accompanied by a neurological improvement (24 h NIHSS: tPA = 11 and control = 15; p = 0.024) and a mortality reduction (tPA = 9.75% vs. controls = 28.2%; p = 0.038). Patients who improved and those who recanalised had the lowest IL-6 levels (p < 0.005). tPA treatment reduces the severity of the inflammatory phenomena that follows stroke. These results may partially explain the efficacy of reperfusion therapy on stroke outcome.

Delay between emergency room arrival and stroke consultation

We reviewed retrospectively the charts of all stroke patients admitted through our emergency room (ER) during the first halves of 1986 (Group A) and 1992 (Group B). Specifically, the time elapsed between ER arrival and the request for consultation by neurology or neurosurgery was subjected to comparison by analysis of variance. In Group A, the time elapsed from arrival to consultation request varied between 1 and 100 min (mean, 32.5). In Group B, the same period ranged from 2 to 285 min (mean, 84). The difference in mean elapsed time between the two groups was statistically significant (<0.0001). In Group A, patients with hemorrhagic events had significantly shorter delay between arrival and consultation (p = 0.026). This was not the case in Group B. Stroke type did not influence the time to consultation in Group A (p = 0.18) orGroupB (p = 0.60). The results show that neurologic and neurosurgical consultations of stroke patients in the ER are delayed more now than in the past. This finding may have a significant impact on acute stroke intervention trials and underscores the need for active collaboration between stroke specialists and emergency physicians.

CD40-1C>T polymorphism (rs1883832) is associated with brain vessel reocclusion after fibrinolysis in ischemic stroke

AIMS

To find genetic predictors of reocclusion after successful fibrinolytic therapy during the acute phase of ischemic stroke.

PATIENTS & METHODS

This was a case-case prospective study analyzing 236 polymorphisms in a cohort of 222 patients treated with tissue plasminogen activator, from which 16 patients suffered a reocclusion event (7.2%). A predictive scale was generated using independent polymorphisms with a dominant/recessive model and tandem occlusion, weighted by their beta-coefficients in logistic regression.

RESULTS

Using a dominant/recessive model, the rs1800801 SNP from the MGP gene (odds ratio [OR]: 15.25; 95% CI: 2.23-104.46; adjusted p = 0.006) and the rs1883832 SNP from CD40 gene (OR: 0.077; 95% CI: 0.009-0.66; adjusted p = 0.019) were independently associated with reocclusion after logistic regression adjustment by clinical predictors. In an additive model, only the rs1883832 SNP (OR: 4.43; 95% CI: 1.62-12.15; adjusted p = 0.004) was related to reocclusion occurrence. The predictive model that was generated stratified the reocclusion risk from less than 1% to more than 70%. Reocclusions were associated with neurological worsening at 24 h (patients with reocclusion: 26.7%, versus patients without reocclusion: 4.9%; p = 0.002), as it was seen for MGP -7A>G (AA: 17.2% vs AG+GG: 4.5%; p = 0.027), but not for CD40 1C>T (CC: 4.5% vs CT+TT: 7.7%; p = 0.565). There was an association between CD40 -1C>T genotype and CD40 transcriptional activity in peripheral blood mononuclear cells (median expression values TT: 65.75%, CT: 70.80%, CC: 96.00%; p = 0.023). However, CD40 soluble fraction was not a useful biomarker of reocclusion status.

CONCLUSION

An association was found between MGP -7A>G and CD40 -1C>T polymorphisms, and reocclusion risk. The predictive scale that was generated permits the stratification of patients by their reocclusion risk with higher accuracy than clinical parameters alone.

Equipoise among recanalization strategies

Modern acute ischemic stroke therapy is based on the premise that recanalization and subsequent reperfusion are essential for the preservation of brain tissue and favorable clinical outcomes. We outline key issues that we think underlie equipoise regarding the comparative clinical efficacy of IV recombinant tissue-type plasminogen activator (rt-PA) and intra-arterial (IA) reperfusion therapies for acute ischemic stroke. On the one hand, IV rt-PA therapy has the benefit of speed with presumed lower rates of recanalization of large artery occlusions as compared to IA methods. More recent reports of major arterial occlusions treated with IV rt-PA, as measured by transcranial Doppler and magnetic resonance angiography, demonstrate higher rates of recanalization. Conversely, IA therapies report higher recanalization rates, but are hampered by procedural delays and risks, even failing to be applied at all in occasional patients where time to reperfusion remains a critical factor. Higher rates of recanalization in IA trials using clot-removal devices have not translated into improved patient functional outcome as compared to trials of IV therapy. Combined IV-IA therapy promises to offer advantages of both, but perhaps only when applied in the timeliest of fashions, compared to IV therapy alone. Where equipoise exists, randomizing subjects to either IV rt-PA therapy or IV therapy followed by IA intervention, while incorporating new interventions into the study design, is a rational and appropriate research approach.

Thrombolysis with reteplase, an unglycosylated plasminogen activator variant, in experimental embolic stroke

We incorporated diffusion-weighted magnetic resonance imaging (MRI) (DWI) and perfusion-weighted MRI (PWI) to evaluate the efficacy of thrombolysis in experimental embolic stroke using a plasminogen activator, reteplase. Reteplase (rPA) is an unglycosylated plasminogen activator with enhanced fibrinolytic potency. Right internal carotid arteries of 34 rabbits were embolized using aged heterologous thrombi. Baseline DWI and PWI scans 0.5 hours after embolization confirmed successful embolization among 32. Intravenous treatment with rPA (n=11; 1 mg/kg bolus), recombinant tissue plasminogen activator (rt-PA) (n=11; 6 mg/kg bolus over 1 hour), or placebo (n=10) commenced 1 hour after stroke induction. MRIs were performed at 1.75, 3, and 5 hours after embolization. Six hours after embolization, brains were harvested and examined for hemorrhage. Posttreatment areas of diffusion abnormality and perfusion delay were graded using both a semiquantitative scale and percent areas expressed as a ratio of the baseline values. Improved perfusion was seen among the rt-PA, and rPA-treated groups compared with placebo, using a semiquantitative scale (P<.01 rt-PA v controls, P<.05, rPA v controls). DWI scans, however, were not improved with thrombolysis. Cerebral hemorrhage was not increased with thrombolytic treatment, although the incidence of wound site hemorrhage was higher with either rPA or rt-PA. One fatal systemic hemorrhage was observed in each of the thrombolytic-treated groups. Cerebral perfusion was equally improved with either rt-PA or rPA without causing excess cerebral hemorrhage. An advantage of rPA is single-bolus dosing rather than continuous infusion. Use of rPA for stroke treatment should be further explored.

Randomized trial of Cervene, a kappa receptor-selective opioid antagonist, in acute ischemic stroke

The purpose of this randomized trial was to confirm drug safety and to obtain preliminary efficacy data on Cervene (nalmefene), an opioid antagonist with relative kappa receptor selectivity, for the treatment of acute ischemic stroke. Patients were treated for 24 hours with either intravenous Cervene (0.05 mg/kg as an initial infusion over 15 minutes and 0.01 mg/kg/h maintenance) or placebo within 6 hours of an ischemic stroke. Efficacy was assessed by comparing the change from baseline to day 7 in the National Institutes of Health stroke scale score (NIHSSS) and the Glasgow Outcome Scale and Barthel Index at 3 months. Forty-four evaluable patients were randomized (3:1) to Cervene (n = 34; treated at 5.0 +/- 0.9 hours after onset) and placebo (n = 10; treated at 4.6 +/- 1.5 hours). No deaths or serious adverse events reasonably attributable to Cervene have been reported. A "major improvement" (NHSSS > 4) was seen at day 7: placebo, 33% (three of nine patients) and Cervene, 66% (19 of 29 patients). Only patients with initial NIHSSS >/= 4 were considered evaluable for this primary endpoint. "Good recovery" at 3 months (Glasgow = 5) was as follows: placebo, 50% (5 of 10 patients) and Cervene, 73% (24 of 33 patients). The death rate at 3 months was placebo, 20% (2 of 10 patients) and Cervene, 9.1% (3 of 33 patients). One patient was lost to follow-up. In conclusion, results from this randomized trial suggest that Cervene is safe, tolerable, and may be beneficial in the treatment of acute stroke patients.

Stroke Therapy Academic Industry Roundtable (STAIR) recommendations for extended window acute stroke therapy trials

The Stroke Therapy Academic Industry Roundtable (STAIR) meetings focus on helping to advance the development of acute stroke therapies. Further extending the time window for acute stroke therapies is an important endeavor for increasing the number of stroke patients who might benefit from treatment. The STAIR group recommends that future extended time window trials initially should focus on selected patient groups most likely to respond to investigational therapies and that penumbral imaging is one tool that may identify such patients. The control group in these trials should receive best locally available medical care; if regulatory approval for intravenous (i.v.) tPA is extended to 4.5 hours, then tPA will become the most appropriate comparator in trials conducted within this time window. In future well-designed extended window clinical trials randomization is appropriate and should not be precluded by using unproven treatment with intraarterial (i.a.) thrombolysis or mechanical devices. For proof of concept, extended time window, phase II trials of i.v. thrombolysis, or mechanical devices in which early recanalization/reperfusion is the primary end point, rescue therapy/bailout treatment with i.a. thrombolysis or devices may be acceptable. Statistical considerations and definitions of successful recanalization/reperfusion are suggested for these trials.

Impact of neurological and medical complications on 3-month outcomes in acute ischaemic stroke

OBJECTIVE

To evaluate the impact of neurological and medical complications on 3-month outcomes in acute ischaemic stroke patients.

METHODS

We prospectively investigated complications for all the consecutive acute ischaemic stroke patients admitted within 7 days from onset in four university hospitals during a 1-year period. Baseline data and 3-month outcomes were collected. Poor outcome was defined as a modified Rankin Scale score 3-6.

RESULTS

A total of 1 254 patients were recruited: 264 (21.1%) and 303 (24.2%) patients experienced one or more neurological and medical complications, respectively. The most common complications were ischaemic stroke progression (17.1%) and pneumonia (12.0%). Of 1 233 patients with available 3-month outcomes, 34.9% had a poor outcome. Multivariate analysis revealed that neurological (odds ratio, 95% confidence interval; 5.47, 3.63-8.24) and medical (3.47, 2.30-5.23) complications were independent predictors of the poor outcome. For the individual complications, ischaemic stroke progression (7.48, 4.73-11.84), symptomatic hemorrhagic transformation (3.57, 1.33-9.54), pneumonia (4.44, 2.20-8.99), extracranial bleeding (4.45, 1.88-10.53), and urinary tract infection (2.72, 1.32-5.60) were independently associated with the poor outcome.

CONCLUSION

Outcome after ischaemic stroke is adversely influenced by complications, especially ischaemic stroke progression, symptomatic hemorrhagic transformation, pneumonia, extracranial bleeding, and urinary tract infection. Interventions to prevent those complications might improve ischaemic stroke outcome.

Does body weight influence the response to intravenous tissue plasminogen activator in stroke patients?

BACKGROUND

The recommended dose of IV tissue plasminogen activator (t-PA) for ischemic stroke patients weighing >100 kg (ISPW >100 kg) is fixed at 90 mg. Elevated levels of plasminogen activator inhibitor-1 (PAI-1) and impaired fibrinolysis have been reported in heavy patients, suggesting that ISPW >100 kg may require higher doses of t-PA. We hypothesized that ISPW >100 kg are less likely to benefit from IV t-PA compared to patients who weigh <or=100 kg and receive a weight-based dose.

METHODS

We queried the National Institute of Neurological Disorders and Stroke t-PA study database, and performed multivariate logistic regression analyses to analyze the effects of weight (>100 vs. <or=100 kg) and t-PA dose on functional outcomes at 3 months.

RESULTS

Six percent of the t-PA and 10% of the placebo cohorts had an actual body weight >100 kg. Weight >100 kg emerged as a predictor of worse outcome (OR = 5.76; p = 0.017) and neurological deterioration (OR = 3.4; p = 0.07) after t-PA. This negative impact of body weight on outcome was not seen among placebo-treated patients. We also found a trend for an association between lower doses of t-PA and unfavorable 3-month outcomes in t-PA-treated patients (OR = 1.9; p = 0.05).

CONCLUSIONS

ISPW >100 kg seem to derive less benefit from IV t-PA than their lighter counterparts. This may be partly attributed to the use of fixed non-weight-adjusted dosing in heavier patients. The mechanism(s) underlying this observation and its potential therapeutic implications require further investigations.

Intravenous thrombolysis with low-dose recombinant tissue plasminogen activator in central retinal artery occlusion

PURPOSE

To evaluate the beneficial effect of intravenous thrombolysis aiming at rapid restoration of blood flow during the early hours of a central retinal artery occlusion (CRAO).

DESIGN

Interventional case series.

METHODS

In the present study, we prospectively evaluated the visual outcome after thrombolytic treatment with low-dose (50 mg) rt-PA (recombinant tissue plasminogen activator) and concomitant intravenous heparinization in patients with acute CRAO, best-corrected visual acuity (BCVA) < or = 20/100, and onset of symptoms within 12 hours prior to treatment.

RESULTS

Twenty-eight patients (28 eyes) were included in this study. Final visual acuity was improved three or more lines in nine eyes (32%), stable in 18 (64%), and worse in one eye. Time to treatment < or = 6.5 hours was associated with a better gain of lines of vision (P = .004). Seven of 17 eyes (41%) that received thrombolytic treatment within the first 6.5 hours achieved a final BCVA > or = 20/50, compared to none in the subgroup of patients with onset to treatment >6.5 hours (P = .023). We observed no serious adverse events.

CONCLUSIONS

Our findings indicate that thrombolytic treatment with intravenous low-dose rt-PA is of value for an improved visual recovery in patients with acute CRAO, if administered within the first 6.5 hours after the onset of symptoms.

Effect of low frequency ultrasound on combined rt-PA and eptifibatide thrombolysis in human clots

INTRODUCTION

Fibrinolytics such as recombinant tissue plasminogen activator (rt-PA) are used to treat thrombotic disease such as acute myocardial infarction (AMI) and ischemic stroke. Interest in increasing efficacy and reducing side effects has led to the study of adjuncts such as GP IIb-IIIa inhibitors and ultrasound (US) enhanced thrombolysis. Currently, GP IIb-IIIa inhibitor and fibrinolytic treatment are often used in AMI, and are under investigation for stroke treatment. However, little is known of the efficacy of combined GP IIb-IIIa inhibitor, fibrinolytic and ultrasound treatment. We measure the lytic efficacy of rt-PA, eptifibatide (Epf) and 120 kHz ultrasound treatment in an in-vitro human clot model.

MATERIALS AND METHODS

Blood was drawn from 15 subjects after IRB approval. Clots were made in 20 microL pipettes, and placed in a water tank for microscopic visualization during lytic treatment. Clots were exposed to control, rt-PA (rt-PA), eptifibatide (Epf), or rt-PA+eptifibatide (rt-PA + Epf), with (+US) or without (-US) ultrasound for 30 minutes at 37 degrees C in human plasma. Clot lysis was measured over time, using a microscopic imaging technique. The fractional clot loss (FCL) and initial lytic rate (LR) were used to quantify lytic efficacy.

RESULTS AND CONCLUSIONS

LR values for (- US) treated clots were 0.8+/-0.1(control), 1.8+/-0.3 (Epf), 1.5+/-0.2 (rt-PA), and 1.3+/-0.4 (rt-PA + Epf) (% clot width/minute) respectively. In comparison, the (+ US) group exhibited LR values of 1.6+/-0.2 (control), 4.3+/-0.4 (Epf), 6.3+/-0.4 (rt-PA), and 4.6+/-0.6 (rt-PA + Epf). For (- US) treated clots, FCL was 6.0+/-0.8 (control), 9.2+/-2.5 (Epf), 15.6+/-1.7 (rt-PA), and 28.0+/-2.2% (rt-PA + Epf) respectively. FCL for (+ US) clots was 13.5+/-2.4 (control), 20.7+/-6.4 (Epf), 44.4+/-3.6 (rt-PA) and 30.3+/-3.6% (rt-PA + Epf) respectively. Although the addition of eptifibatide enhances the in-vitro lytic efficacy of rt-PA in the absence of ultrasound, the efficacy of ultrasound and rt-PA is greater than that of combined ultrasound, rt-PA and eptifibatide exposure.

Comparison of combined venous and arterial thrombolysis with primary arterial therapy using recombinant tissue plasminogen activator in acute ischemic stroke

OBJECTIVE

We sought to compare the safety and efficacy of combined intravenous (IV) and intra-arterial (IA) thrombolysis with primary IA therapy using tissue plasminogen activator for acute ischemic stroke presenting within 6 hours of symptom onset.

METHODS

We performed quasirandomization of a single institution's prospectively collected stroke database, comparing IV/IA (0.6 mg/kg IV < or = 60 mg, followed by 0.3 mg/kg IA < or = 30 mg) versus primary IA. Outcome measures include 90-day modified Rankin scale score, mortality, symptomatic intracerebral hemorrhage, and recanalization rates. Statistical analysis was performed using bivariate and propensity score methods.

RESULTS

Of 1057 patients, 41 patients were treated with IV/IA, and 55 with IA. There was significant difference in time to treatment (mean of 151 minutes for the combined group and 261 minutes for the IA, P < .0001) and arterial tissue plasminogen activator dose (17.5 mg for IV/IA v 22.8 mg for IA only, P = .05). Propensity score matching yielded 25 patients in each group. Symptomatic intracerebral hemorrhage rate was 12% in each group. Mortality was 20% in the IV/IA group versus 16% in the IA group (relative risk 1.3 [0.4-4.1], P = .7). More patients in IV/IA group had modified Rankin scale score less than or equal to 2 (odds ratio 1.6 [0.5-5.8], P = .3). Recanalization was 64% with IV/IA versus 48% with IA (odds ratio 1.9 [0.5-7.0], P = .3).

CONCLUSION

This study demonstrates that both combined IV/IA and primary IA recombinant tissue plasminogen activator therapy is feasible and safe in the treatment of acute ischemic stroke. Combined IV/IA therapy may be associated with an improvement in clinical outcome without a significant increase in the risk of symptomatic intracerebral hemorrhage and mortality compared with IA therapy.

[IV t-pA thrombolysis in acute stroke patients]

Intravenous administration of tissue plasminogen activator (t-PA) can improve clinical outcome in patients with acute ischemic stroke. In our country, use of t-PA for acute brain infarction within 3 hours of onset was approved by Japanese government from October, 2005. About 5,700 patients were treated with t-PA for these two years. Analysis of 2,484 patients (mean 70 years old, median NIHSS Score 15) showed that mRS 0-1 was 32%, the death was 20% and symptomatic brain hemorrhage was 5.2%. We had 63 patients (median 74 years old, median NIHSS score 14) treated with t-PA thrombolysis by November, 2007. Immediately after t-PA therapy 8 patients (12.7%) had dramatic recovery. On day 7 after t-PA therapy, excellent recovery was 49.2%, good recovery was 15.9%, and worsening was 12.7%. Within one hour after t-PA therapy, rate of recanalization for occluded arteries was 43.5%, which was strongly associated with excellent and good neurological recovery on day 7. Atrial fibrillation was an independent factor associated with no early recanalization. When we evaluated baseline DWI findings before t-PA infusion using DWI-ASPECTS and NIHSS score at day 7 after rt-PA therapy, bad outcome was seen more frequently in patients with an DWI ASPECTS < or = 5 (6 of 8 patients) than in patients with an DWI ASPECTS > 5 (2 of 41 patients; P < 0.0001). Patients with an ASPECTS-DWI > 5 should be considered eligible for t-PA therapy.

Methodology of the Interventional Management of Stroke III Trial

RATIONALE

The Interventional Management of Stroke (IMS) I and II pilot trials demonstrated that the combined intravenous (i.v.) and intraarterial (i.a.) approach to recanalization may be more effective than standard i.v. rt-PA (Activase) alone for moderate-to-large National Institutes of Health Stroke Scale (NIHSS>or=10) strokes, and with a similar safety profile.

AIMS

The primary objective of this NIH-funded, Phase III, randomized, multicenter, open-label clinical trial is to determine whether a combined i.v./i.a. approach to recanalization is superior to standard i.v. rt-PA alone when initiated within 3 h of acute ischemic stroke onset. The IMS III trial will develop and maintain a network of interventional centers to test the safety, feasibility, and potential efficacy of new FDA-approved catheter devices as part of a combined i.v./i.a. approach to recanalization as the IMS III study progresses. A secondary objective of the IMS III trial is to determine the cost-effectiveness of the combined i.v./i.a. approach as compared with standard i.v. rt-PA. Trial enrollment began in July of 2006.

DESIGN

A projected 900 subjects with moderate-to-large (NIHSS>or=10) ischemic strokes between ages 18 and 80 will be enrolled over the next 5 years at 40-plus centers in the United States and Canada. Patients must have i.v. treatment initiated within 3 h of stroke onset in both arms. Subjects will be randomized in a 2 : 1 ratio with more subjects enrolled in the combined i.v./i.a. group. The i.v. rt-PA alone group will receive the standard full dose [0.9 mg/kg, 90 mg maximum (10% as bolus)] of rt-PA intravenously over an hour. The combined i.v./i.a. group will receive a lower dose of i.v. rt-PA ( approximately 0.6 mg/kg, 60 mg maximum) over 40 min, followed by immediate angiography. If a treatable thrombus is not demonstrated, no i.a. therapy will be administered. If an appropriate thrombus is identified, treatment will continue with either the Concentric Merci thrombus-removal device, infusion of rt-PA and delivery of low-intensity ultrasound at the site of the occlusion via the EKOS Micro-Infusion Catheter, or infusion of rt-PA via a standard microcatheter. If i.a. rt-Pa therapy is the chosen strategy, a maximum of 22 mg of i.a. rt-PA may be given. The choice of i.a. strategy will be made by the treating neurointerventionalist. The i.a. treatment must begin within 5 h and be completed within 7 h of stroke onset.

STUDY OUTCOMES

The primary outcome measure is a favorable clinical outcome, defined as a modified Rankin Scale Score of 0-2 at 3 months. The primary safety measure is mortality at 3 months and symptomatic ICH within the 24 h of randomization.