Use of intravenous heparin by North American neurologists: do the data matter?

Geographic differences in pharmacotherapy patterns and outcomes of acute ischemic stroke in China

BACKGROUND

Vast economic and healthcare status discrepancies exist among regions in China, contributing to different treatment patterns. This study was aimed to investigate the current status of pharmacotherapy for acute ischemic stroke (AIS) and outcomes in China and explore the geographic variation in stroke care.

METHODS

This study was a multicenter prospective registry study, which collected the data of patients with AIS from 80 hospitals in 46 cities in 2015-2017 across China. Poor functional outcome defined as a modified Rankin Scale score of 3-6 was assessed at 3 and 12 months. Multivariate logistic regression was used.

RESULTS

Among 9973 eligible patients, the number of receiving intravenous thrombolysis (IVT), antiplatelet agents, anticoagulants, statin and human urinary kallidinogenase was 429 (4.3%), 9363 (93.9%), 1063 (10.7%), 6828 (74.7%) and 5112 (51.2%), respectively. Multivariable analysis showed IVT use in northeastern was significantly more frequent than in eastern region (OR = 3.17, 95% CI, 2.53-3.99), while the antiplatelets agents use were less frequent (OR = 0.46, 95%CI: 0.38-0.57). The proportions of poor outcomes at 3 and 12 months were 20.7% and 15.8%, respectively. Multivariate analysis showed AIS patients from northeastern and central region had significantly lower risk of poor outcome at month 3 and 12 than those from eastern region (all P < 0.05).

CONCLUSIONS

There was a low IVT use and a high antiplatelet agent and statin use for AIS in China. The pharmacotherapy and prognosis of AIS had variation by geographic region.

TRIAL REGISTRATION

This study was registered with ClinicalTrials.gov (NCT02470624).

Antiplatelet, cytotoxic activities and characterization of green-synthesized zinc oxide nanoparticles using aqueous extract of Nephrolepis exaltata

The goal of the current study was to synthesize zinc oxide nanoparticles (ZnO-NPs) using ZnCl₂.2H₂O salt precursor and an aqueous extract of Nephrolepis exaltata (N. exaltata), which act as a capping and reducing agent. N. exaltata plant extract-mediated ZnO-NPs were further characterized by various techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR), UV-visible (UV-Vis), and energy-dispersive X-ray (EDX) analysis. The nanoscale crystalline phase of ZnO-NPs was analyzed by the XRD patterns. The FT-IR analysis revealed different functional groups of biomolecules involved in the reduction and stabilization of the ZnO-NPs. The light absorption and optical properties of ZnO-NPs were examined by UV-Vis spectroscopy at a wavelength of 380 nm. The spherical shape morphology of ZnO-NPs with mean particle size ranges between 60 and 80 nm was confirmed by SEM images. While the EDX analysis was used to identify the elemental composition of ZnO-NPs. Furthermore, the synthesized ZnO-NPs demonstrate potential antiplatelet activity by inhibiting the platelet aggregation induced by platelet activation factor (PAF) and arachidonic acid (AA). The results showed that synthesized ZnO-NPs were more effective in inhibiting platelet aggregation induced by AA with IC₅₀ (56% and 10 μg/mL) and PAF (63% and 10 μg/mL), respectively. However, the biocompatibility of ZnO-NPs was assessed in human lung cancer cell line (A549) under in vitro conditions. The cytotoxicity of synthesized nanoparticles revealed that cell viability decreased and the IC₅₀ was found to be 46.7% at a concentration of 75 μg/mL. The present work concluded the green synthesis of ZnO-NPs that was achieved by N. exaltata plant extract and showed good antiplatelet and cytotoxic activity, which demonstrates the lack of harmful effects making them more effective for use in pharmaceutical and medical fields to treat thrombotic disorders.

Anticoagulation decisions in elderly patients with stroke

Primary and secondary prevention of stroke is often a challenge in elderly patients due to the increase in both thrombotic and hemorrhagic risks with age. In some cases, there is sufficient data in the elderly population to allow recommendations or anticoagulation decisions to be made, such as for the indication of anticoagulation to prevent stroke related to atrial fibrillation (AF) or the choice of oral anticoagulant therapy in this situation. In other situations, the less robust data leave some questions; this is the case for the delay to initiate an oral anticoagulant therapy after an AF-related ischemic stroke, for the management of antithrombotic treatment after a stroke of undetermined cause or after intracranial bleeding or in a high-risk bleeding situation associated with stroke in the elderly subject. These issues will be discussed in this paper.

Anticoagulation After Stroke in Patients With Atrial Fibrillation

Background and Purpose- Bridging therapy with low-molecular-weight heparin reportedly leads to a worse outcome for acute cardioembolic stroke patients because of a higher incidence of intracerebral bleeding. However, this practice is common in clinical settings. This observational study aimed to compare (1) the clinical profiles of patients receiving and not receiving bridging therapy, (2) overall group outcomes, and (3) outcomes according to the type of anticoagulant prescribed. Methods- We analyzed data of patients from the prospective RAF and RAF-NOACs studies. The primary outcome was defined as the composite of ischemic stroke, transient ischemic attack, systemic embolism, symptomatic cerebral bleeding, and major extracerebral bleeding observed at 90 days after the acute stroke. Results- Of 1810 patients who initiated oral anticoagulant therapy, 371 (20%) underwent bridging therapy with full-dose low-molecular-weight heparin. Older age and the presence of leukoaraiosis were inversely correlated with the use of bridging therapy. Forty-two bridged patients (11.3%) reached the combined outcome versus 72 (5.0%) of the nonbridged patients (P=0.0001). At multivariable analysis, bridging therapy was associated with the composite end point (odds ratio, 2.3; 95% CI, 1.4-3.7; P<0.0001), as well as ischemic (odds ratio, 2.2; 95% CI, 1.3-3.9; P=0.005) and hemorrhagic (odds ratio, 2.4; 95% CI, 1.2-4.9; P=0.01) end points separately. Conclusions- Our findings suggest that patients receiving low-molecular-weight heparin have a higher risk of early ischemic recurrence and hemorrhagic transformation compared with nonbridged patients.

Impact of Guidelines on Clinical Practice: Intravenous Heparin Use for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Since its introduction, controversy has existed about the administration of intravenous heparin for the treatment of acute ischemic stroke. We studied trends in the intravenous heparin use during a 6-year time period and the potential influence of clinical guidelines in national language on intravenous heparin administration in Korea.

METHODS

On the basis of a prospective nationwide multicenter stroke registry, we collected data on patients with acute ischemic stroke who arrived within 7 days of symptom onset during the time period 2008 to 2013. We studied patient demographics, prestroke medical history, stroke characteristics, and stroke treatment. Data from a total of 23 425 patients from 12 university hospitals or regional stroke centers were analyzed.

RESULTS

The administration of intravenous heparin steadily decreased throughout the study period: 9.7% in 2008, 10.9% in 2009, 9.4% in 2010, 6.0% in 2011, 4.7% in 2012, and 4.3% in 2013 (P for trend <0.001). The reduced intravenous heparin use was associated with moderate stroke severity, atrial fibrillation, and stroke of cardioembolic, other-, and undetermined etiology. In a multivariable logistic model, increase of 1 calendar year (odds ratio, 0.89; 95% confidence interval, 0.84-0.95; P<0.001) and release of clinical practice guidelines in Korean (odd ratio, 0.74; 95% confidence interval, 0.59-0.91; P<0.01) were independent factors associated with reduction in the frequency of intravenous heparin use.

CONCLUSIONS

Use of intravenous heparin for acute ischemic stroke treatment has decreased in Korea, and this change may be attributable to the spread and successful implementation of regional clinical practice guidelines.

Retrospective study of Heparin Administration for Ischemic Stroke when there is an IV-tPA Contraindication

Background:

The majority of patients presenting with an ischemic stroke arrive after the 3-4.5 h time window allowed for intravenous tissue plasminogen activator (IV tPA) administration. Most of the literature on heparin use in acute ischemic stroke does not describe dose-adjusted intravenous unfractionated heparin (IV UFH) without bolus, a common method of administration. This study was designed to test whether an anticoagulation regimen of intravenous dose-adjusted UFH with no bolus, in patients with a contraindication to IV TPA, administered within 24 h of an acute ischemic stroke could be effective and safe.

Methods:

We conducted a retrospective study of 273 patients over two consecutive years with acute ischemic stroke, who were outside the window for IV tPA. All patients had imaging studies on admission. The primary outcome measure of the study was to evaluate the safety of dose-adjusted IV UFH use in the setting of acute stroke. We looked at duration of heparin infusion, average partial thromboplastin time (PTT) value, and the incidence of new hemorrhagic events.

Results:

A total of 273 patients met the inclusion criteria. These patients received heparin infusion within 24 h of symptom onset. The duration of intravenous heparin infusion ranged from 1 to 18 days with a mean of 4 days. Mean PTT value was 72.4. Hemorrhagic complications occurred in 26 patients (9.5%), and included 12 asymptomatic petechial or hemorrhagic conversion (4.3%), 2 symptomatic intracranial hemorrhages (0.7%), 5 gastrointestinal bleeds (2 requiring transfusion and interventions), 2 patients experienced benign hematuria, 4 patients with groin hematomas, and one neck hematoma.

Conclusion:

This study suggests that intravenous dose-adjusted UFH with no bolus can be administered to patients with acute ischemic stroke with relative safety.

Anticoagulation therapy is harmful to large-sized cerebellar infarction

AIM

Anticoagulants are commonly used to treat ischemic stroke. Its impact on cerebellar infarction has not been fully understood.

METHODS

In the clinical study, we reviewed a consecutive series of patients with large-sized cerebellar infarction (diameter > 3 cm, n = 30) treated with or without anticoagulation. In animal study, cerebellar infarction operation was performed in 12 Cynomolgus monkeys. Then the animals were administrated with low molecular weight heparin (LMWH) or vehicle for 14 days.

RESULTS

Six patients died during the following treatment. All the subjects that died received anticoagulation therapy, while nobody in the survival group received such a therapy. Compared with sham-operated animals, all monkeys with cerebellar infarction have obvious neurological deficits. The number and size of the Purkinje cells in the cerebellar area were also reduced. Two animals in the LMWH group (33%) died, while all animals in the vehicle control group survived. Compared with the vehicle group, the neurological score in the LMWH group was significantly increased (P < 0.05). The water content in the cerebella was also significantly higher (P < 0.05). Edema, hemorrhage, and subarachnoid hemorrhage occurred in the cerebella as well as brainstem of all the LMWH treated animals.

CONCLUSIONS

These results indicated the harmful effects of anticoagulation therapy on large-sized cerebellar infarction.

Therapists' use of the Graded Repetitive Arm Supplementary Program (GRASP) intervention: a practice implementation survey study

BACKGROUND

Only a small percentage of research is ever successfully translated into practice. The Graded Repetitive Arm Supplementary Program (GRASP) is a stroke rehabilitation intervention that anecdotally has had rapid translation from research to clinical practice. This study was conducted to explore the characteristics of this practice implementation.

OBJECTIVES

The aims of this study were: (1) to explore the extent of practice implementation of GRASP in the United Kingdom; (2) using an implementation framework, to explore UK therapists' opinions of implementing GRASP; and (3) if GRASP is found to be used in the United Kingdom, to investigate differences in opinions between therapists who are using GRASP in practice and those who are not.

DESIGN

A cross-sectional study design was used.

METHODS

Data were collected via an online questionnaire. Participants in this study were members of the College of Occupational Therapy Specialist Section Neurological Practice and the Association of Chartered Physiotherapists Interested in Neurology.

RESULTS

Of the 274 therapists who responded to the survey, 61 (22.3%) had experience of using GRASP, 114 (41.6%) knew of GRASP but had never used it, and 99 (36.1%) had never heard of GRASP. Therapists displayed positive opinions toward the implementation of a manual with graded progressions of structured upper limb exercises for people after stroke. Opinions were different between therapists who had used GRASP and those who had not.

LIMITATIONS

The findings of this study may be limited by response bias.

CONCLUSIONS

GRASP is a relatively new stroke rehabilitation intervention that has made impressive translation into the knowledge and practice of UK therapists. Therapists' opinions would suggest that GRASP is both an acceptable and feasible intervention and has the potential to be implemented by a greater number of therapists in a range of settings.

Targeted use of heparin, heparinoids, or low-molecular-weight heparin to improve outcome after acute ischaemic stroke: an individual patient data meta-analysis of randomised controlled trials

Background

Many international guidelines on the prevention of venous thromboembolism recommend targeting heparin treatment at patients with stroke who have a high risk of venous thrombotic events or a low risk of haemorrhagic events. We sought to identify reliable methods to target anticoagulant treatment and so improve the chance of avoiding death or dependence after stroke.

Methods

We obtained individual patient data from the five largest randomised controlled trials in acute ischaemic stroke that compared heparins (unfractionated heparin, heparinoids, or low-molecular-weight heparin) with aspirin or placebo. We developed and evaluated statistical models for the prediction of thrombotic events (myocardial infarction, stroke, deep vein thrombosis, or pulmonary embolism) and haemorrhagic events (symptomatic intracranial or significant extracranial) in the first 14 days after stroke. We calculated the absolute risk difference for the outcome “dead or dependent” in patients grouped by quartiles of predicted risk of thrombotic and haemorrhagic events with random effect meta-analysis.

Findings

Patients with ischaemic stroke who were of advanced age, had increased neurological impairment, or had atrial fibrillation had a high risk of both thrombotic and haemorrhagic events after stroke. Additionally, patients with CT-visible evidence of recent cerebral ischaemia were at increased risk of thrombotic events. In evaluation datasets, the area under a receiver operating curve for prediction models for thrombotic events was 0·63 (95% CI 0·59–0·67) and for haemorrhagic events was 0·60 (0·55–0·64). We found no evidence that the net benefit from heparins increased with either increasing risk of thrombotic events or decreasing risk of haemorrhagic events.

Interpretation

There was no evidence that patients with ischaemic stroke who were at higher risk of thrombotic events or lower risk of haemorrhagic events benefited from heparins. We were therefore unable to define a targeted approach to select the patients who would benefit from treatment with early anticoagulant therapy. We recommend that guidelines for routine or selective use of heparin in stroke should be revised.

Funding

MRC.

Guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The authors present an overview of the current evidence and management recommendations for evaluation and treatment of adults with acute ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators responsible for the care of acute ischemic stroke patients within the first 48 hours from stroke onset. These guidelines supersede the prior 2007 guidelines and 2009 updates.

METHODS

Members of the writing committee were appointed by the American Stroke Association Stroke Council's Scientific Statement Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Panel members were assigned topics relevant to their areas of expertise, reviewed the stroke literature with emphasis on publications since the prior guidelines, and drafted recommendations in accordance with the American Heart Association Stroke Council's Level of Evidence grading algorithm.

RESULTS

The goal of these guidelines is to limit the morbidity and mortality associated with stroke. The guidelines support the overarching concept of stroke systems of care and detail aspects of stroke care from patient recognition; emergency medical services activation, transport, and triage; through the initial hours in the emergency department and stroke unit. The guideline discusses early stroke evaluation and general medical care, as well as ischemic stroke, specific interventions such as reperfusion strategies, and general physiological optimization for cerebral resuscitation.

CONCLUSIONS

Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke remains urgently needed.

Discarding heparins as treatment for progressive stroke in Sweden 2001 to 2008

BACKGROUND AND PURPOSE

High-dose heparin has been used extensively to treat patients with progressive ischemic stroke, but the scientific support is poor and the current stroke guidelines advise against its use. We studied how heparin treatment for progressive stroke has been discarded in Sweden.

METHODS

All 78 hospitals in Sweden that admit acute stroke patients participate in Riks-Stroke, the Swedish Stroke Register. During 2001 to 2008, information on the use of high-dose heparin was available for 155,344 patients with acute ischemic stroke. The determinants as to region, patient characteristics, and stroke service settings were analyzed.

RESULTS

Use of heparin for progressive stroke declined from 7.5% (2001) to 1.6% (2008) of all patients with ischemic stroke. The marked regional differences present in 2001 were reduced over time. The use of heparin declined at a similar rate in all types of hospital settings, in stroke units vs nonstroke units, and in neurological vs medical wards. Independent predictors of use of heparin included younger age, first-ever stroke, independence in activities of daily living before stroke, atrial fibrillation, no aspirin treatment, and lowered consciousness on admission.

CONCLUSIONS

There is no immediate, stepwise effect of new scientific information and national guidelines on clinical practice. Rather, the phasing out of heparin has followed a linear course over several years, with less variation between hospitals. We speculate that open comparisons between hospitals in a national stroke register may have helped to reduce the variations in clinical practice.

Optimal dosing of intravenous unfractionated heparin bolus in transient ischemic attack or stroke

Early initiation of heparin therapy for treatment of stroke is not only associated with an improved outcome, but also with the risk of hemorrhagic transformation. We compared the efficacy of three unfractionated heparin bolus regimens (0 U/kg, 30 U/kg, or 80 U/kg) in achieving a therapeutic activated partial thromboplastin time over the first 6-hour period in a cohort of 54 patients admitted with transient ischemic attack or stroke. Patients treated with the low bolus dose (30 U/kg) were more often within the therapeutic range for activated partial thromboplastin time at two hours after the initial bolus than patients treated with the other regimens. The percentage of therapeutic activated partial thromboplastin time results within the first six hours of treatment was greater in the group treated with the low bolus dose. Using the low bolus dose may reduce complication rates and improve clinical outcomes in the future clinical trials.

Molecular mechanisms of thrombus formation in ischemic stroke: novel insights and targets for treatment

In ischemic stroke, treatment options are limited. Therapeutic thrombolysis is restricted to the first few hours after stroke, and the utility of current platelet aggregation inhibitors, including GPIIb/IIIa receptor antagonists, and anticoagulants is counterbalanced by the risk of intracerebral bleeding complications. Numerous attempts to establish neuroprotection in ischemic stroke have been unfruitful. Thus, there is strong demand for novel treatment strategies. Major advances have been made in understanding the molecular functions of platelet receptors such as glycoprotein Ib (GPIb) and GPVI and their downstream signaling pathways that allow interference with their function. Inhibition of these receptors in the mouse stroke model of transient middle cerebral artery occlusion prevented infarctions without increasing the risk of intracerebral bleeding. Similarly, it is now clear that the intrinsic coagulation factor XII (FXII) and FXI play a functional role in thrombus formation and stabilization during stroke: their deficiency or blockade protects from cerebral ischemia without overtly affecting hemostasis. Based on the accumulating evidence that thrombus formation and hemostasis are not inevitably linked, new concepts for prevention and treatment of ischemic stroke may eventually emerge without the hazard of severe bleeding complications. This review discusses recent advances related to antithrombotic strategies in experimental stroke research.

Anticoagulants for acute ischaemic stroke

BACKGROUND

Most ischaemic strokes are caused by blood clots blocking an artery in the brain. Clot prevention with anticoagulants might improve outcome if bleeding risks were low. This is an update of a Cochrane review first published in 1995, and previously updated in 2004.

OBJECTIVES

To assess the effect of anticoagulant therapy versus control in the early treatment (less than 14 days) of patients with acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched 2 October 2007), and two Internet clinical trials registries for relevant ongoing studies (last searched October 2007).

SELECTION CRITERIA

Randomised trials comparing early anticoagulant therapy (started within two weeks of stroke onset) with control in patients with acute presumed or confirmed ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial quality, and extracted the data.

MAIN RESULTS

Twenty-four trials involving 23,748 participants were included. The quality of the trials varied considerably. The anticoagulants tested were standard unfractionated heparin, low-molecular-weight heparins, heparinoids, oral anticoagulants, and thrombin inhibitors. Based on 11 trials (22,776 participants) there was no evidence that anticoagulant therapy reduced the odds of death from all causes (odds ratio (OR) 1.05; 95% confidence interval (CI) 0.98 to 1.12) at the end of follow up. Similarly, based on eight trials (22,125 participants), there was no evidence that anticoagulants reduced the odds of being dead or dependent at the end of follow up (OR 0.99; 95% CI 0.93 to 1.04). Although anticoagulant therapy was associated with fewer recurrent ischaemic strokes (OR 0.76; 95% CI 0.65 to 0.88), it was also associated with an increase in symptomatic intracranial haemorrhages (OR 2.55; 95% CI 1.95 to 3.33). Similarly, anticoagulants reduced the frequency of pulmonary emboli (OR 0.60; 95% CI 0.44 to 0.81), but this benefit was offset by an increase in extracranial haemorrhages (OR 2.99; 95% CI 2.24 to 3.99).

AUTHORS' CONCLUSIONS

Since the last version of the review, neither of the two new relevant studies have provided additional information to change the conclusions. In patients with acute ischaemic stroke, immediate anticoagulant therapy is not associated with net short or long-term benefit. Treatment with anticoagulants reduced recurrent stroke, deep vein thrombosis and pulmonary embolism, but increased bleeding risk. The data do not support the routine use of any the currently available anticoagulants in acute ischaemic stroke.

Guidelines for the Early Management of Adults With Ischemic Stroke

Purpose— Our goal is to provide an overview of the current evidence about components of the evaluation and treatment of adults with acute ischemic stroke. The intended audience is physicians and other emergency healthcare providers who treat patients within the first 48 hours after stroke. In addition, information for healthcare policy makers is included.

Methods— Members of the panel were appointed by the American Heart Association Stroke Council’s Scientific Statement Oversight Committee and represented different areas of expertise. The panel reviewed the relevant literature with an emphasis on reports published since 2003 and used the American Heart Association Stroke Council’s Levels of Evidence grading algorithm to rate the evidence and to make recommendations. After approval of the statement by the panel, it underwent peer review and approval by the American Heart Association Science Advisory and Coordinating Committee. It is intended that this guideline be fully updated in 3 years.

Results— Management of patients with acute ischemic stroke remains multifaceted and includes several aspects of care that have not been tested in clinical trials. This statement includes recommendations for management from the first contact by emergency medical services personnel through initial admission to the hospital. Intravenous administration of recombinant tissue plasminogen activator remains the most beneficial proven intervention for emergency treatment of stroke. Several interventions, including intra-arterial administration of thrombolytic agents and mechanical interventions, show promise. Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke is needed.

Guidelines for the early management of adults with ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council, Clinical Cardiology Council, Cardiovascular Radiology and Intervention Council, and the Atherosclerotic Peripheral Vascular Disease and Quality of Care Outcomes in Research Interdisciplinary Working Groups: the American Academy of Neurology affirms the value of this guideline as an educational tool for neurologists

PURPOSE

Our goal is to provide an overview of the current evidence about components of the evaluation and treatment of adults with acute ischemic stroke. The intended audience is physicians and other emergency healthcare providers who treat patients within the first 48 hours after stroke. In addition, information for healthcare policy makers is included.

METHODS

Members of the panel were appointed by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and represented different areas of expertise. The panel reviewed the relevant literature with an emphasis on reports published since 2003 and used the American Heart Association Stroke Council's Levels of Evidence grading algorithm to rate the evidence and to make recommendations. After approval of the statement by the panel, it underwent peer review and approval by the American Heart Association Science Advisory and Coordinating Committee. It is intended that this guideline be fully updated in 3 years.

RESULTS

Management of patients with acute ischemic stroke remains multifaceted and includes several aspects of care that have not been tested in clinical trials. This statement includes recommendations for management from the first contact by emergency medical services personnel through initial admission to the hospital. Intravenous administration of recombinant tissue plasminogen activator remains the most beneficial proven intervention for emergency treatment of stroke. Several interventions, including intra-arterial administration of thrombolytic agents and mechanical interventions, show promise. Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke is needed.

Established treatments for acute ischaemic stroke

This article reviews the recommended management of patients presenting to accident and emergency departments with acute ischaemic stroke, and focuses on thrombolysis. The review includes initial management, recommended clinical, laboratory, and radiographic examinations. Appropriate general medical care, consisting of monitoring of oxygenation, fever, blood pressure, and blood glucose concentrations are examined. Criteria for thrombolysis with intravenous recombinant tissue plasminogen activator (rt-PA) are discussed. Complications of rt-PA therapy, such as haemorrhagic transformation and angio-oedema, are reviewed. An approach to management of rt-PA complications is outlined. Only a small percentage of acute ischaemic stroke patients meet criteria for rt-PA; therefore, alternative acute treatment strategies are also discussed. Acute medical and neurological complications in stroke patients are analysed, along with recommendations for treatment.

Anticoagulation Strategies for Treatment of Ischemic Stroke and Antiphospholipid Syndrome: Case Report and Review of the Literature

A 49-year-old Caucasian man with antiphospholipid syndrome who experienced an ischemic stroke required multidisciplinary decisions regarding acute and long-term care. The patient first received warfarin and unfractionated heparin, followed by low-molecular-weight heparin. However, he developed complications from these drugs (warfarin-induced necrosis and heparin-induced thrombocytopenia), resulting in thigh necrosis and multiple additional cerebral and peripheral infarcts. His condition improved after warfarin and the heparins were discontinued, and a direct thrombin inhibitor, argatroban, was given intravenously for acute treatment. Argatroban is the only anticoagulant known to be safe in patients who experience an acute ischemic stroke in the setting of heparin-induced thrombocytopenia. For long-term anticoagulation, fondaparinux, an indirect, selective factor Xa inhibitor, was given subcutaneously. The patient received intravenous dexamethasone, later changed to azathioprine, for immunomodulatory treatment. He had significant improvement in his neurologic deficits without recurrent events over the next 18 months. Management of anticoagulation therapy in patients with antiphospholipid syndrome is complex and challenging, and therapeutic strategies need to be evaluated further.

National study on emergency department visits for transient ischemic attack, 1992-2001

OBJECTIVES

To describe the epidemiology of U.S. emergency department (ED) visits for transient ischemic attack (TIA) and to measure rates of antiplatelet medication use, neuroimaging, and hospitalization during a ten-year time period.

METHODS

The authors obtained data from the 1992-2001 National Hospital Ambulatory Medical Care Survey. TIA cases were identified by having ICD-9 code 435.

RESULTS

From 1992 to 2001, there were 769 cases, representing 2,969,000 ED visits for TIA. The population rate of 1.1 ED visits per 1,000 U.S. population (95% CI = 0.92 to 1.30) was stable over time. TIA was diagnosed in 0.3% of all ED visits. Physicians administered aspirin and other antiplatelet agents to a small percentage of patients, and 42% of TIA patients (95% CI = 29% to 55%) received no medications at all in the ED. Too few data points existed to measure a statistically valid trend over time. Physicians performed computed tomography scanning in 56% (95% CI = 45% to 66%) of cases and performed magnetic resonance imaging (MRI) in < 5% of cases, and there was a trend toward increased imaging over time. Admission rates did not increase during the ten-year period, with 54% (95% CI = 42% to 67%) admitted. Regional differences were noted, however, with the highest admission rate found in the Northeast (68%).

CONCLUSIONS

Between 1992 and 2001, the population rate of ED visits for TIA was stable, as were admission rates (54%). Antiplatelet medications appear to be underutilized and to be discordant with published guidelines. Neuroimaging increased significantly. These findings may reflect the limited evidence base for the guidelines, educational deficits, or other barriers to guideline implementation.

Symptomatic intracerebral hematomas in posterior circulation stroke patients anticoagulated with heparin

BACKGROUND

A lot of clinicians use heparin in patients with posterior circulation stroke. Frequency and risk factors of symptomatic intracerebral hematoma (ICH) in posterior circulation infarct patients anticoagulated with unfractionated heparin are not known.

METHODS

To determine the incidence and the risk factors of the heparin-related ICH in posterior circulation infarct patients, we retrospectively reviewed the clinical features of 37 patients who had acute posterior circulation infarct and received intravenous heparin after they underwent brain computed tomographic scans and diffusion-weighted imaging (DWI). Follow-up brain scans were obtained at any time if clinical symptoms worsened. Volumes of acute posterior circulation infarction were calculated on DWI.

RESULTS

Of 37 patients, four (10.8%) developed symptomatic ICH during heparin infusion. The location of ICH was cerebellum in all the hemorrhagic worsening patients. We found that the size of an acute infarction calculated on DWI is the risk factor of symptomatic ICH during intravenous heparin therapy in patients with posterior circulation infarct.

CONCLUSIONS

Until a large prospective study is performed, it may be prudent to avoid heparin infusion in patients with large posterior circulation infarct documented on DWI.

Geriatric neurologic emergencies

Geriatrics is an important subspecialty within the field of emergency medicine and represents a burgeoning area of practice. The special vulnerability of elderly patients to neurologic disease and injury and the comparative subtlety of clinical presentation mean that physicians should have a lower threshold for laboratory studies, radiologic imaging, consultation, and admission. Transferring appropriate patients to tertiary centers that offer specialized trauma and neurologic and neurosurgical care greatly enhances survival and functional outcomes.

Antithrombotic agents' use in patients with atrial fibrillation and acute cerebral ischemia

BACKGROUND

although trials suggest a benefit of aspirin, and not of anticoagulation (AC), in the acute stage of cerebral ischemia associated with atrial fibrillation (AF), many neurologists still use heparin.

OBJECTIVE

to evaluate how antithrombotic agents were used at the acute stage of cerebral ischemia in AF patients after the publication of trials and guidelines.

METHODS

we reviewed the charts of all patients with AF who were admitted between 1996 and 2002 as primary care patients, within 48 hours after onset of an ischemic stroke (IS) or transient ischemic attacks (TIAs). We recorded the first antithrombotic treatment prescribed at admission.

RESULTS

in 763 consecutive patients (42% men; median age 79 years), the use of AC on admission decreased over time from 70% to 22% (p<0.001), while antiplatelet agents increased from 27% to 78% (p<0.001). Patients who received AC were more likely to be younger, to have a Barthel index >60, no hemorrhagic changes, and to have been admitted in 1996 or 1997. Results were similar between patients with IS and TIAs and in patients who were not under AC before. In patients who were under oral AC before, AC use at admission did not decline over time (p=0.366).

CONCLUSION

there was a clear decrease in AC use during the study period, except in patients who were already under AC before, and in TIA patients.

Are There Patients With Acute Ischemic Stroke and Atrial Fibrillation That Benefit From Low Molecular Weight Heparin?

Background and Purpose— Treatment doses of heparins are not recommended for acute ischemic stroke. Despite this, their use in this setting is widespread. We investigated whether subgroups of patients with acute ischemic stroke and atrial fibrillation, identified by clinical, hemostatic ( d- dimer, prothombin fragments 1+2 [F 1+2 ], soluble fibrin monomer), or inflammatory (C-reactive protein [CRP]) variables might have a differential response to low molecular weight heparin (LMWH) over aspirin. In addition, we sought to identify factors associated with a poor clinical outcome at 3 months.

Methods— We conducted a post hoc subgroup analysis of a randomized, placebo-controlled, double-blind trial (Heparin in Acute Embolic Stroke Trial) designed to test the hypothesis that treatment doses of LMWH (dalteparin; 100 IU/kg BID) would be superior to aspirin (160 mg per day) in patients with acute ischemic stroke and atrial fibrillation. For the current analysis, 431 participants were included. The primary outcome measure was a poor outcome at 3 months, defined as death or dependency in activities of daily living. Using regression analysis, we determined whether any of the chosen variables were associated with a differential response to dalteparin (treatment interaction) or with poor outcome.

Results— In the multivariable logistic regression model, none of the clinical, hemostatic, or inflammatory variables were associated with a significant treatment interaction. Stroke severity (odds ratio [OR], 1.09 [95% CI, 1.07 to 1.12]), increasing age (OR, 1.09 [CI, 1.05 to 1.14]), CRP level (OR, 1.32 [CI, 1.04 to 1.66]), and F 1+2 level (OR, 1.77 [CI, 1.07 to 2.91]) were independently associated with a poor outcome at 3 months.

Conclusions— Our study does not support the use of treatment doses of LMWH in any of the studied subgroups of patients with acute ischemic stroke and atrial fibrillation. Age, stroke severity, CRP, and F 1+2 were predictive of poor outcome at 3 months.

Steady plasma concentration of unfractionated heparin reduces infarct volume and prevents inflammatory damage after transient focal cerebral ischemia in the rat

Unfractionated heparin (UH) decreases the extent of infarction after transient focal brain ischemia in the rat and abridges neuroinflammatory damage in patients with acute stroke. This study was aimed at assessing whether controlled and steady heparinemia in plasma can reduce infarct volume and exert neuroprotective effects after ischemia. Infarct volume was measured at 24 and 7 days following a 1-hr intraluminal middle cerebral artery (MCA) occlusion in rats treated with UH or with vehicle. After testing several UH administration protocols, we choose to give a bolus of 200 U/kg, which was started 3 hr after the occlusion, followed by a 24-hr intraperitoneal perfusion of 70 U/kg/hr, which maintained a 24-hr steady plasma heparinemia (0.3-0.6 U/ml) and caused no CNS or systemic bleeding. In addition, plasma IL-10 concentration was measured by ELISA, endothelial VCAM-1 expression was evaluated by i.v. injection of a (125)I-labeled monoclonal antibody against VCAM-1, and brain hemeoxygenase-1 (HO-1) expression was determined by Western blot. UH-treated rats showed smaller infarctions than rats treated with vehicle, as well as higher IL-10 plasma levels and HO-1 brain expression and lower endothelial VCAM-1 induction. The study shows that a stable plasma concentration of UH given at nonhemorrhagic doses reduces infarct volume after ischemia-reperfusion in the rat. It also shows that UH prevented the induction of cell adhesion molecules in the cerebral vasculature and increased the expression of molecules with antiinflammatory and prosurvival properties. These findings support further testing of the clinical value of parenteral, adjusted, high-dose UH in patients with acute stroke.

Literature-searching strategies to improve the application of evidence-based clinical practice principles to stroke care

The field of cerebrovascular disease is evolving more rapidly than ever. New evidence from primary research in stroke is available and should be guiding global changes in practice. Instead, there is a disappointing and ever-widening evidence-practice gap. Busy health care practitioners are encouraged to practice evidence-based medicine, but their skills in this field are deficient. The purpose of this article is to provide the steps necessary to quickly, efficiently, and independently locate high-quality, valid evidence-based information on stroke that can be applied in a point-of-care setting. A discussion of secondary stroke prevention highlights these steps.

Transient ischemic attack: review for the emergency physician

In the past few years, the approach to patients with transient ischemic attacks has undergone a transformation. To care for these patients, emergency physicians must understand these changes. They must be comfortable with the diagnosis and treatment of transient ischemic attacks in their emergency department. To this end, we ask and answer the following 6 important questions in this up-to-date review of transient ischemic attacks: (1) How is a transient ischemic attack defined? (2) Does this patient have a transient ischemic attack? (3) Once diagnosed, what diagnostic evaluation should be done (and when)? (4) What treatment should be instituted (and when)? (5) What is the correct disposition? and (6) What are the current medical guidelines?

Anticoagulants for acute ischaemic stroke

BACKGROUND

Most ischaemic strokes are caused by blood clots blocking an artery in the brain. Clot prevention with anticoagulant therapy could have a significant impact on patient survival, disability and stroke recurrence.

OBJECTIVES

The objective of this review was to assess the effect of anticoagulant therapy versus control in the early treatment of patients with acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group trials register (last searched 30 October 2003). For previous updates of this review, we searched the register of the Antithrombotic Trialists' (ATT) Collaboration, consulted MedStrategy (1995), and contacted relevant drug companies.

SELECTION CRITERIA

Randomised trials comparing early anticoagulant therapy (started within two weeks of stroke onset) with control in patients with acute presumed or confirmed ischaemic stroke.

DATA COLLECTION AND ANALYSIS

Two reviewers independently selected trials for inclusion, assessed trial quality and extracted the data.

MAIN RESULTS

Twenty-two trials involving 23,547 patients were included. The quality of the trials varied considerably. The anticoagulants tested were standard unfractionated heparin, low-molecular-weight heparins, heparinoids, oral anticoagulants, and thrombin inhibitors. Based on nine trials (22,570 patients) there was no evidence that anticoagulant therapy reduced the odds of death from all causes (odds ratio (OR) = 1.05, 95% confidence interval (CI) 0.98 to 1.12) at the end of follow-up. Similarly, based on six trials (21,966 patients), there was no evidence that anticoagulants reduced the odds of being dead or dependent at the end of follow-up (OR = 0.99; 95% CI 0.93 to 1.04). Although anticoagulant therapy was associated with about 9 fewer recurrent ischaemic strokes per 1000 patients treated (OR = 0.76; 95% CI 0.65 to 0.88), it was also associated with a similar sized 9 per 1000 increase in symptomatic intracranial haemorrhages (OR = 2.52; 95% CI 1.92 to 3.30). Similarly, anticoagulants avoided about 4 pulmonary emboli per 1000 (OR = 0.60, 95% CI 0.44 to 0.81), but this benefit was offset by an extra 9 major extracranial haemorrhages per 1000 (OR = 2.99; 95% CI 2.24 to 3.99). Sensitivity analyses did not identify a particular type of anticoagulant regimen or patient characteristic associated with net benefit.

REVIEWERS' CONCLUSIONS

Immediate anticoagulant therapy in patients with acute ischaemic stroke is not associated with net short- or long-term benefit. The data from this review do not support the routine use of any type of anticoagulant in acute ischaemic stroke. People treated with anticoagulants had less chance of developing deep vein thrombosis (DVT) and pulmonary embolism (PE) following their stroke, but these sorts of blood clots are not very common, and may be prevented in other ways.