Antithrombotic and Thrombolytic Therapy for Ischemic Stroke

A Biomimicking and Multiarm Self-Indicating Nanoassembly for Site-Specific Photothermal-Potentiated Thrombolysis Assessed in Microfluidic and In Vivo Models

Thrombolytic and antithrombotic therapies are limited by short circulation time and the risk of off-target hemorrhage. Integrating a thrombus-homing strategy with photothermal therapy are proposed to address these limitations. Using glycol chitosan, polypyrrole, iron oxide and heparin, biomimicking GCPIH nanoparticles are developed for targeted thrombus delivery and thrombolysis. The nanoassembly achieves precise delivery of polypyrrole, exhibiting biocompatibility, selective accumulation at multiple thrombus sites, and enhanced thrombolysis through photothermal activation. To simulate targeted thrombolysis, a microfluidic model predicting thrombolysis dynamics in realistic pathological scenarios is designed. Human blood assessments validate the precise homing of GCPIH nanoparticles to activated thrombus microenvironments. Efficient near-infrared phototherapeutic effects are demonstrated at thrombus lesions under physiological flow conditions ex vivo. The combined investigations provide compelling evidence supporting the potential of GCPIH nanoparticles for effective thrombus therapy. The microfluidic model also offers a platform for advanced thrombolytic nanomedicine development.

Correlation Between Calcification Characteristics of Carotid Atherosclerotic Plaque and Plaque Vulnerability

Purpose

To investigate the relationship between calcification characteristics of carotid atherosclerotic plaque and lipid rich necrotic core (LRNC) and intraplaque hemorrhage (IPH).

Methods

Patients with severe carotid stenosis undergoing carotid endarterectomy (CEA) were selected. Ultrasound and CT angiography (CTA) were performed to evaluate the calcification characteristics of the plaque before the surgery.

Results

A total of 142 patients were included and 142 pathological specimens of postoperative plaque were obtained accordingly. There were 78 plaques (54.9%) with LRNC and 41 (28.9%) with IPH. The plaque with LRNC had higher calcification rate (93.6%) compared with the plaque with IPH (87.8%). LRNC was often found in multiple calcification (P = 0.003) and mixed type calcification (P = 0.001). Multiple calcification was more likely to combine with IPH (P = 0.008), while simple basal calcification was not likely to combine IPH (P = 0.002). Smaller granular calcification was more likely to be associated with IPH (P < 0.05). In multivariate regression analysis of IPH and calcification characteristics, simple basal calcification was still a protective factor for IPH (OR, 0.25; 95% CI, 0.09–0.66; P = 0.005), while multiple calcification was closely related to the occurrence of IPH (OR, 3.58; 95% CI, 1.49–8.61; P = 0.004).

Conclusion

Calcification characteristics of carotid atherosclerotic plaques are closely related to the vulnerability of plaques, especially multiple calcification and mixed type calcification.

Hemorrhagic stroke

Hemorrhagic stroke comprises about 20% of all strokes, with intracerebral hemorrhage (ICH) being the most common type. Frequency of ICH is increased where hypertension is untreated. ICH in particularly has a disproportionately high risk of early mortality and long-term disability. Until recently, there has been a paucity of randomized controlled trials (RCTs) to provide evidence for the efficacy of various commonly considered interventions in ICH, including acute blood pressure management, coagulopathy reversal, and surgical hematoma evacuation. Evidence-based guidelines do exist for ICH and these form the basis for a framework of care. Current approaches emphasize control of extremely high blood pressure in the acute phase, rapid reversal of vitamin K antagonists, and surgical evacuation of cerebellar hemorrhage. Lingering questions, many of which are the topic of ongoing clinical research, include optimizing individual blood pressure targets, reversal strategies for newer anticoagulant medications, and the role of minimally invasive surgery. Risk stratification models exist, which derive from findings on clinical exam and neuroimaging, but care should be taken to avoid a self-fulfilling prophecy of poor outcome from limiting treatment due to a presumed poor prognosis. Cerebral venous thrombosis is an additional subtype of hemorrhagic stroke that has a unique set of causes, natural history, and treatment and is discussed as well.

Setting performance benchmarks for stroke care delivery: Which quality indicators should be prioritized in quality improvement; an analysis in 500,331 stroke admissions

BACKGROUND AND AIM

Benchmarking is a management approach for implementing best medical practices at the lowest cost. The objectives of this study were to set achievable performance benchmarks for individual quality indicators to determine the predicted quality achievement related to better adherence, and to select optimal quality indicators for improving the quality of acute ischemic stroke care.

METHODS

We analyzed data on 500,331 patients diagnosed with acute ischemic stroke who were treated at 518 hospitals in China from January 2011 to May 2017. The primary outcome was independence (modified Rankin Scale score ≤2) at discharge. Data-driven achievable benchmarking used the "pared-mean" approach to set objective performance targets. Hierarchical logistic regression models were employed to evaluate the process-outcome association, as well as the predicted quality improvement if all hospitals were to operate at the benchmark level.

RESULTS

Of the overall population, 64.01% were independent patients at discharge. The performance benchmarks were >90% for most of the quality indicators. After adjusting for patient-level and hospital-level characteristics and unifying hospital performance to the benchmark level, the quality indicators with high increase in both overall adherence rate and independence rate were thrombolytic therapy, anticoagulant therapy, venous thrombosis prophylaxis.

CONCLUSIONS

Performance targets for three acute treatments, including thrombolytic therapy, anticoagulant therapy, venous thrombosis prophylaxis, could best motivate improvements in both overall adherence rate and independence rate at discharge. The finding suggests that the above three types of acute treatment should be given priority to improve the quality of acute ischemic stroke care.

Nanoparticle-microglial interaction in the ischemic brain is modulated by injury duration and treatment

Cerebral ischemia is a major cause of death in both neonates and adults, and currently has no cure. Nanotechnology represents one promising area of therapeutic development for cerebral ischemia due to the ability of nanoparticles to overcome biological barriers in the brain. ex vivo injury models have emerged as a high-throughput alternative that can recapitulate disease processes and enable nanoscale probing of the brain microenvironment. In this study, we used oxygen-glucose deprivation (OGD) to model ischemic injury and studied nanoparticle interaction with microglia, resident immune cells in the brain that are of increasing interest for therapeutic delivery. By measuring cell death and glutathione production, we evaluated the effect of OGD exposure time and treatment with azithromycin (AZ) on slice health. We found a robust injury response with 0.5 hr of OGD exposure and effective treatment after immediate application of AZ. We observed an OGD-induced shift in microglial morphology toward increased heterogeneity and circularity, and a decrease in microglial number, which was reversed after treatment. OGD enhanced diffusion of polystyrene-poly(ethylene glycol) (PS-PEG) nanoparticles, improving transport and ability to reach target cells. While microglial uptake of dendrimers or quantum dots (QDs) was not enhanced after injury, internalization of PS-PEG was significantly increased. For PS-PEG, AZ treatment restored microglial uptake to normal control levels. Our results suggest that different nanoparticle platforms should be carefully screened before application and upon doing so; disease-mediated changes in the brain microenvironment can be leveraged by nanoscale drug delivery devices for enhanced cell interaction.

Antithrombotic Treatment in Cardiomyopathies

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Cardiomyopathies are a heterogeneous group of heart muscle diseases and important cause of heart failure with reduced or preserved ejection fraction. Although there is an increasing body of evidence on the incidence, pathophysiology, and natural history of heart failure (HF) in cardiomyopathies, certain aspects of the therapeutic strategies remain unclear. More particularly, there is no consensus if to whether antithrombotic therapy has a favorable risk: benefit ratio in reducing thromboembolic event rate in patients with cardiomyopathies without suffering from primary valvular disease or atrial fibrillation. Although the observational data on increased venous thromboembolic risk are supported by multiple pathophysiological mechanisms, the role of antithrombotic therapy in these patients remains unclear. This review article provides an overview of epidemiologic, pathophysiologic, clinical, and therapeutic data for the prevention of thromboembolism in heart failure due to cardiomyopathies.

Antithrombotic Therapy in Carotid Artery Disease

The management of asymptomatic atherosclerotic carotid artery disease and the role of antithrombotic therapy is of increasing importance for stroke prevention. Non-invasive imaging of carotid plaques can identify high-risk plaque features that are associated with the risk of plaque rupture. Carotid plaque necrosis, hemorrhage, fibrous cap thinning, and the presence of foam cells have all been correlated with the risk of rupture and onset of neurological symptoms in patients with carotid stenosis. Antiplatelets are currently recommended for patients with a history of ischemic stroke and/or significant carotid artery stenosis, with aspirin and clopidogrel being the most widely used and studied agents. The role of dual antiplatelet therapy remains controversial. Moreover, there is scarce evidence on the role of newer anticoagulant agents in stable patients with carotid artery stenosis. In this review article, we discuss the pathophysiology of carotid atherosclerosis, the use of non-invasive imaging for detecting the vulnerable carotid plaque and summarize the existing clinical evidence on the use of antiplatelet and antithrombotic agents in carotid artery disease.

Liu S, A. Camargo C, Aburawi E, Moeckel M, Slagman A, Christ M, Singer A, Tazarourte K, Rathlev NK, A. Grossman S, Bellou A. Association between boarding in the emergency department and in-hospital mortality: A systematic review

IMPORTANCE

Boarding in the emergency department (ED) is a critical indicator of quality of care for hospitals. It is defined as the time between the admission decision and departure from the ED. As a result of boarding, patients stay in the ED until inpatient beds are available; moreover, boarding is associated with various adverse events.

STUDY OBJECTIVE

The objective of our systematic review was to determine whether ED boarding (EDB) time is associated with in-hospital mortality (IHM).

METHODS

A systematic search was conducted in academic databases to identify relevant studies. Medline, PubMed, Scopus, Embase, Cochrane, Web of Science, Cochrane, CINAHL and PsychInfo were searched. We included all peer-reviewed published studies from all previous years until November 2018. Studies performed in the ED and focused on the association between EDB and IHM as the primary objective were included. Extracted data included study characteristics, prognostic factors, outcomes, and IHM. A search update in PubMed was performed in May 2019 to ensure the inclusion of recent studies before publishing.

RESULTS

From the initial 4,321 references found through the systematic search, the manual screening of reference lists and the updated search in PubMed, a total of 12 studies were identified as eligible for a descriptive analysis. Overall, six studies found an association between EDB and IHM, while five studies showed no association. The last remaining study included both ICU and non-ICU subgroups and showed conflicting results, with a positive association for non-ICU patients but no association for ICU patients. Overall, a tendency toward an association between EDB and IHM using the pool random effect was observed.

CONCLUSION

Our systematic review did not find a strong evidence for the association between ED boarding and IHM but there is a tendency toward this association. Further well-controlled, international multicenter studies are needed to demonstrate whether this association exists and whether there is a specific EDB time cut-off that results in increased IHM.

Clinical Performance Measures for Neurocritical Care: A Statement for Healthcare Professionals from the Neurocritical Care Society

BACKGROUND

Performance measures are tools to measure the quality of clinical care. To date, there is no organized set of performance measures for neurocritical care.

METHODS

The Neurocritical Care Society convened a multidisciplinary writing committee to develop performance measures relevant to neurocritical care delivery in the inpatient setting. A formal methodology was used that included systematic review of the medical literature for 13 major neurocritical care conditions, extraction of high-level recommendations from clinical practice guidelines, and development of a measurement specification form.

RESULTS

A total of 50,257 citations were reviewed of which 150 contained strong recommendations deemed suitable for consideration as neurocritical care performance measures. Twenty-one measures were developed across nine different conditions and two neurocritical care processes of care.

CONCLUSIONS

This is the first organized Neurocritical Care Performance Measure Set. Next steps should focus on field testing to refine measure criteria and assess implementation.

Long-Term Evolutionary Change in the Lumen of Intracranial Atherosclerotic Stenosis Following Angioplasty and Stenting

BACKGROUND

Angioplasty and stenting is a recognized treatment option for patients with intracranial atherosclerosis.

OBJECTIVE

To evaluate the long-term evolutionary luminal changes of intracranial atherosclerosis after angioplasty and stenting.

METHODS

This was a retrospective study with patient consent. Eighty-two patients presenting with acute and minor cerebral ischemia due to stenosis ≥70%, who had received medical therapy with or without stenting (Wingspan), were invited. Luminal imaging was provided using 3-dimensional rotational angiography (3-DRA) at baseline and 12 mo, and cone-beam computed tomography angiography with intravenous contrast (CBCT) was provided at follow-up (median 82.4 mo [interquartile range 61.9-96.9 mo]).

RESULTS

Thirty-six patients in the stenting group and 26 patients in the medical group were recruited and completed the study. There was no statistically significant difference in demographics between the 2 patient groups. The luminal gain at 12 or 80 mo as compared to baseline in the stenting group was significantly greater than that in the medical group (12 mo: median gain 30% vs 7.2%, P < .001; 80 mo: median gain 42.9% vs 7.2%, P < .0001). Luminal loss or unchanged lumen was correlated with recurrent ischemic event. The differences in the stenosis degree assessment between CBCT and 3-DRA in the same 10 patients with or without stenting were 1.2 ± 0.6% or 0.2 ± 0.06%, respectively. There was a correlation between recurrent ischemic events and luminal loss.

CONCLUSION

Arterial lumen after angioplasty and stenting can probably be well maintained and delayed luminal gain does occur, long-term luminal loss is associated with recurrent ischemic events, CBCT might be useful as a less-invasive means for long-term assessment.

Measurement of Thromboxane Biosynthesis in Health and Disease

Thromboxane (TX) A₂ is a chemically unstable lipid mediator involved in several pathophysiologic processes, including primary hemostasis, atherothrombosis, inflammation, and cancer. In human platelets, TXA₂ is the major arachidonic acid derivative via the cyclooxygenase (COX)-1 pathway. Assessment of platelet TXA₂ biosynthesis can be performed ex vivo through measurement of serum TXB₂, an index of platelet COX-1 activity, as well as in vivo through measurement of urinary enzymatic metabolites, a non-invasive index of platelet activation. This article reviews the main findings of four decades of clinical investigation based on these analytical approaches, focusing on the measurement of TXA₂ metabolites to characterize the pathophysiologic role of transiently or persistently enhanced platelet activation and to describe the clinical pharmacology of COX-1 inhibition in health and disease.

Health Care Costs and Utilization of Dabigatran Compared With Warfarin for Secondary Stroke Prevention in Patients With Nonvalvular Atrial Fibrillation: A Retrospective Population Study

BACKGROUND

It remains unclear whether the use of new oral anticoagulants, compared with warfarin, is economically beneficial in Asian countries.

OBJECTIVE

The objective of this study is to compare the health care costs and utilization between dabigatran and warfarin in a real-world nonvalvular atrial fibrillation (NVAF) population.

RESEARCH DESIGN

Data were obtained from the Taiwan National Health Insurance Database, and patients with an NVAF diagnosis between June 1, 2012, and May 31, 2014, were identified using the International Classification of Diseases, Ninth Revision code of 427.31. The patients in the dabigatran cohort were matched 1:2 to those in the warfarin cohort by sex, age, residential region, and a propensity score that incorporated a major bleeding history, CHADS2 score, and Charlson Comorbidity Index. The all-cause health care utilization and associated costs of the 2 treatment groups were compared at 3 and 12 months.

RESULTS

A total of 1149 patients taking dabigatran were identified and matched with 2298 warfarin users. During the 3-month observation period, the likelihood of having at least 1 hospitalization among dabigatran users was significantly lower than that of warfarin users (odds ratio=0.78; P=0.001). Patients in the dabigatran group incurred lower mean emergency department costs ($2383.1 vs. $3033.6), mean ischemic stroke-related hospitalization costs ($8869.5 vs. $13,990.5), and mean all-cause hospitalization costs ($32,402.2 vs. $50,669.9) at 3 months. However, both the mean and median outpatient costs of warfarin users were consistently lower than those of dabigatran users ($17,161.2 vs. $24,931.4 and $10,509.0 vs. $20,671.5, respectively). Similar trends were observed at 12 months, except that the 2 groups had comparable total health care costs.

CONCLUSIONS

The use of dabigatran is associated with lower emergency department and all-cause hospitalization costs but greater outpatient costs in a real-world, NVAF patient population compared with warfarin.

Evaluation of the implementation of a 24-hr stroke thrombolysis emergency treatment for patients with acute ischaemic stroke

AIMS AND OBJECTIVES

To assess the trends of intravenous (IV) thrombolysis with recombinant tissue plasminogen activator (rt-PA) among patients with acute ischaemic stroke (AIS) admitted to our hospital between 2012-2014 and investigate the effects of a 24-hr stroke thrombolysis emergency treatment on the intrahospital clinical data and outcomes of these patients treated with IV rt-PA thrombolysis.

BACKGROUND

Although prenotification of stroke by emergency medical services has been endorsed by the national recommendations and implemented in some developed countries, the development in China is limited.

DESIGN

A retrospective, single-centre, observational study.

METHODS

Patients with AIS admitted to our hospital between January 2012-December 2014 were included; those who received IV rt-PA thrombolysis within 4.5 hr of onset were investigated. Demographic characteristics, including age and sex, and clinical data and outcomes, including onset-to-treatment time (OTT), door-to-needle time (DNT), premorbid modified Rankin Scale score and proportion of patients treated per year, were all recorded.

RESULTS

The proportion of patients with AIS who received thrombolytic therapy within 4.5 hr increased from 2012-2014. The baseline characteristics of all patients were similar. Since the implementation of 24-hr stroke thrombolysis emergency treatment in 2013, the median DNT significantly decreased in 2014 after implementation (42 min) compared with that in 2012 before implementation (81 min) (p < .05). Moreover, the admission-to-imaging time (37 vs. 33 vs. 36 min) and OTT (176 vs. 147 vs. 124 min) significantly decreased during the 3 years (p < .05).

CONCLUSIONS

The 24-hr stroke thrombolysis emergency treatment reduced in-hospital delay before thrombolytic therapy but had no effect on the functional outcomes of the patients with AIS.

RELEVANCE TO CLINICAL PRACTICE

This study provides opportunities to improve the experiences in using 24-h stroke thrombolysis emergency treatment in patients with AIS in clinical practice.

The association of duration of boarding in the emergency room and the outcome of patients admitted to the intensive care unit

BACKGROUND

The demand for critical care beds is increasing out of proportion to bed availability. As a result, some critically ill patients are kept in the Emergency Department (ED boarding) awaiting bed availability. The aim of our study is to examine the impact of boarding in the ED on the outcome of patients admitted to the Intensive Care Unit(ICU).

METHODS

This was a retrospective analysis of ICU data collected prospectively at King Abdulaziz Medical City, Riyadh from ED between January 2010 and December 2012 and all patients admitted during this time were evaluated for their duration of boarding. Patients were stratified into three groups according to the duration of boarding from ED. Those admitted less than 6 h were classified as Group I, between 6 and 24 h, Group II and more than 24 h as Group III. We carried out multivariate analysis to examine the independent association of boarding time with the outcome adjusting for variables like age, sex, APACHE, Mechanical ventilation, Creatinine, Platelets, INR.

RESULTS

During the study period, 940 patients were admitted from the ED to ICU, amongst whom 227 (25%) were admitted to ICU within 6 h, 358 (39%) within 6-24 h and 355 (38%) after 24 h. Patients admitted to ICU within 6 h were younger [48.7 ± 22.2(group I) years, 50.6 ± 22.6 (group II), 58.2 ± 20.9 (group III) (P = 0.04)]with less mechanical ventilation duration[5.9 ± 8.9 days (Group I), 6.5 ± 8.1 (Group II) and 10.6 ± 10.5 (Group III), P = 0.04]. There was a significant increase in hospital mortality [51(22.5), 104(29.1), 132(37.2), P = 0.0006) and the ICU length of stay(LOS) [9.55 days (Group I), 9.8 (Group II) and 10.6 (Group III), (P = 0.002)] with increase in boarding duration. In addition, the delay in admission was an independent risk factor for ICU mortality(OR for group III vs group I is 1.90, P = 0.04) and hospital mortality(OR for group III vs Group I is 2.09, P = 0.007).

CONCLUSION

Boarding in the ED is associated with higher mortality. This data highlights the importance of this phenomenon and suggests the need for urgent measures to reduce boarding and to improve patient flow.

Electrochemical impedimetric detection of stroke biomarker NT-proBNP using disposable screen-printed gold electrodes

Stroke is the second top leading cause of death globally. It is caused by an abrupt interruption of blood flow to the brain. In that course, brain natriuretic peptide (BNP) and its derivative N-terminal pro b-type natriuretic peptide (NT-proBNP), neurohormones produced mainly by the heart ventricles in response to excessive stretching of cardiomyocytes (heart muscle cells), are proven to be good biomarkers for heart failure diagnosis. Moreover, there is growing clinical interest of the use of NT-proBNP for stroke diagnosis and prognosis because it is significantly associated with cardioembolic stroke and secondary stroke reoccurrence, with sensitivity >90% and specificity >80%. However, in diagnostic settings, there is still a need to address the encountered analytical problems, particularly assay specificity and set up. In this study, a novel approach for NT-proBNP detection is demonstrated using an electrochemical immunoassay method. A label-free impedimetry immunosensor for stroke biomarker was developed using modified disposable screen-printed gold electrodes (SPGE) hosting specific anti-NT-proBNP capture antibody. The performance of our immunosensor was studied in the presence of NT-proBNP in both buffered and mock (porcine) plasma samples. A linear relation between the relative total resistance (ΔRtot) responses and the NT-proBNP concentrations in buffer was observed in a range from 0.1 to 5 ng mL-1 with a correlation coefficient (R2) of 0.94656. Overall, the biosensor has demonstrated the capability to quantitate NT-proBNP and differentiate such concentrations in a low concentration range, especially among 0, 0.1, 0.5, 1, and 3 ng mL-1 in plasma samples within 25 min. This range is valuable not only for classifying cardioembolic stroke (higher or equal to 0.5 ng mL-1), but also predicting the risk of secondary stroke reoccurrence (higher than 0.255 ng mL-1). Our biosensor has the potential to be used as an easy-to-use point-of-care test that is both accurate and affordable.

How do family medicine residents choose an anticoagulation regimen for patients with nonvalvular atrial fibrillation?

Aim To examine the choices Canadian family medicine residents make for oral anticoagulation (OAC) for patients with nonvalvular atrial fibrillation (AF).

BACKGROUND

AF increases the risk of strokes. An important consideration in AF management is risk stratification for stroke and prescription of appropriate OAC. Family physicians provide the vast majority of OAC prescriptions.

METHODS

We administered a survey to residents in multiple Canadian family medicine training programmes. Questions explored the experiences and attitudes towards risk stratification and choices of OAC when presented with standardized clinical scenarios. In each scenario, a novel oral anticoagulant (NOAC) would be the preferred treatment according to the contemporary Canadian and European guidelines. Findings A total of 247 residents participated in the survey. Most used the congestive heart failure, hypertension, age ≥ 75, diabetes mellitus, stroke or TIA (2 points) (81%) and congestive heart failure, hypertension, age ≥ 75 (2 points) or age 65-74 (1 point), diabetes mellitus, stroke or TIA, vascular disease including peripheral arterial disease, myocardial infarction, or aortic plaque, sex (female) (67%) risk stratification schemes while the preferred bleeding risk stratification scheme was hypertension, abnormal liver or renal function, stroke, bleeding, labile international normalized ratio, elderly (age ≥ 65), drugs or alcohol (84%). In the clinical scenarios, residents generally preferred warfarin in favour of NOACs, independent of training level. Residents ranked the risk of adverse events and the cost to the patient as their most and least important consideration when prescribing OAC, respectively. Therefore in patients with nonvalvular AF, Canadian family medicine residents prefer warfarin in comparison with NOACs despite the latest Canadian and European guideline recommendations. This knowledge gap may be enhanced by multiple factors, including a sometimes magnified fear of adverse events and a rapidly changing landscape in stroke prophylaxis.

Association of Paroxysmal Supraventricular Tachycardia with Ischemic Stroke: A National Case-Control Study

BACKGROUND AND PURPOSE

Cardioembolic stroke accounts for approximately 15%-20% of all ischemic strokes. Atrial fibrillation constitutes one-half to two-thirds of all cardioembolic stroke events. The association of paroxysmal supraventricular tachycardia (PSVT) with ischemic stroke remains unclear. A national case-control study was conducted to identify the risk factors, including PSVT, for ischemic stroke in Taiwan.

METHODS

We designed a national case-control study comprising patients diagnosed with ischemic stroke (n = 5633) from 1997 to 2011; each patient from the case group was randomly matched with the control group (n = 30,895) in Taiwan. Data were retrospectively collected from Taiwan's National Health Insurance Research Database, which contains not only claims data on hospitalization, emergency room visits, and outpatient department visits, but also patient characteristics.

RESULTS

Logistic regression analysis was used to identify the risk factors for ischemic stroke. Independent risk factors for ischemic stroke included age (in 5-year intervals; odds ratio [OR], 1.76; 95% confidence interval [CI], 173-1.78), the male sex (versus the female sex; OR, 1.88; 95% CI, 1.74-2.01), chronic kidney disease (OR, 3.09; 95% CI, 2.67-3.57), PSVT (OR, 2.05; 95% CI, 1.30-3.19), and aspirin use (OR, .04; 95% CI, .03-0.05).

CONCLUSIONS

Our study is the first in Taiwan to identify PSVT as a significant risk factor for ischemic stroke. New antithrombotic regimens, including aspirin, can be recommended for the primary prevention of stroke and for reducing the burden of stroke for patients with PSVT.

Determining Indications for Care Common to Competing Guidelines by Using Classification Tree Analysis: Application to the Prevention of Venous Thromboembolism in Medical Inpatients

Background. Substantial variations have been reported in the advice given by competing guidelines addressing the same clinical problem. Objective. This study aimed to assess the usefulness of classification tree analysis in comparing competing guidelines. Method. The authors implemented a classification tree–growing algorithm on cross-sectional data from 818 patients to determine indications for prophylactic heparin treatment common to 4 competing guidelines disseminated between 1998 and 2000 and addressing the prophylaxis of venous thromboembolism in medical inpatients. Results. The resulting classification tree involved 10 terminal nodes. Its mean accuracy estimated by performing 10-fold cross-validation was 82% (s = 3). The guidelines consistently supported prophylactic heparin treatment for 5 indications: a previous episode of deep vein thrombosis or pulmonary embolism, recent paralysis of lower limb(s), congestive heart failure with one or more risk factors, recent myocardial infarction, and malignancy with one or more risk factors. These indications involved 257 patients (31.4%) and were supported by robust scientific evidence. Deep vein thrombosis was detected in 27 of these patients (10.5%). Two consistent negative indications involved 347 patients (42.4%). Deep vein thrombosis was detected in 9 of these patients (2.6%). Three indications involving 214 patients (26.2%) were discordant over the 4 guidelines. Conclusion. Classification tree analysis of real patient data is a useful strategy to identify indications common to competing guidelines. These indications should be considered for inclusion when updating guidelines. The findings of recently completed randomized trials have partly resolved the disagreement among the 4 guidelines. This approach may be helpful when developing new guidelines or for identifying topics warranting further complementary clinical trials.

Changing Management of Acute Ischaemic Stroke: the New Treatments and Emerging Role of Endovascular Therapy

OPINION STATEMENT

Urgent reperfusion of the ischaemic brain is the aim of stroke treatment, and the last two decades have seen a rapid advancement in the medical and endovascular treatment of acute ischaemic stroke. Intravenous tissue plasminogen activator (tPA) was first introduced as a safe and effective thrombolytic agent followed by the introduction of newer thrombolytic agents as well as anticoagulant and antiplatelet agents, proposed as potentially safer drugs with more favourable interaction profiles. In addition to chemo-thrombolysis, other techniques including transcranial sonothrombolysis and microbubble cavitation have been introduced which are showing promising results, but await large-scale clinical trials. These developments in medical therapies which are undoubtedly of great importance due to their potential widespread and immediate availability are paralleled with gradual but steady improvements in endovascular recanalisation techniques which were initiated by the introduction of the MERCI (Mechanical Embolus Removal in Cerebral Ischemia) and Penumbra systems. The introduction of the Solitaire device was a significant achievement in reliable and safe endovascular recanalisation and was followed by further innovative stent retrievers. Initial trials failed to show a solid benefit in endovascular intervention compared with IV-tPA alone. These counterintuitive results did not last long, however, when a series of very well-designed randomised controlled trials, pioneered by MR-CLEAN, EXTEND-IA and ESCAPE, emerged, confirming the well-believed daily anecdotal evidence. There have now been seven positive trials of endovascular treatment for acute ischaemic stroke. Now that level I evidence regarding the superiority of endovascular recanalisation is abundantly available, the clinical challenge is how to select patients suitable for intervention and to familiarise and educate stroke care providers with this recent development in stroke care. It is important for the interventional services to be provided only in comprehensive stroke centres and endovascular interventions attempted by experienced well-trained operators, at this stage as an adjunct to the established medical treatment of IV-tPA, if there are no contraindications.

[Secondary prevention of ischemic non cardioembolic stroke]

Stroke patients are at high risk for recurrence or new occurrence of other cardiovascular events or cardiovascular mortality. It is estimated that a high percentage of non-cardioembolic ischemic stroke can be prevented by a suitable modification of lifestyle (diet and exercise), reducing blood pressure (BP) with antihypertensive medication, platelet aggregation inhibitors, statins and high intake reducing consumption of. Unfortunately the degree of control of the different risk factors in secondary prevention of stroke is low. The clinical practice guidelines show clear recommendations with corresponding levels of evidence, but only if implemented in a general way they will get a better primary and secondary stroke prevention.

N2 extenuates experimental ischemic stroke through platelet aggregation inhibition

INTRODUCTION

Thromboxane A2 (TXA2) can induce the platelet aggregation and lead to thrombosis. This will cause the low-reflow phenomenon after ischemic stroke and aggravate the damage of brain issues. Therefore, it is potential to develop the drugs inhibiting TXA2 pathway to treat cerebral ischemia.

AIM

This study aims to prove the protective effect of N2 (4-(2-(1H-imidazol-1-yl) ethoxy)-3-methoxybenzoic acid) on focal cerebral ischemia and reperfusion injury through platelet aggregation inhibition.

MATERIALS AND METHODS

Middle cerebral artery occlusion/reperfusion (MCAO/R) is used as the animal model. Neurological deficit score, Morris water maze, postural reflex test, Limb-use asymmetry test, infarct volume, and water content were performed to evaluate the protective effect of N2 in MCAO/R rats. 9, 11-dieoxy-11α, 9α-methanoepoxyprostaglandin F2α (U46619) or adenosine diphosphate (ADP) was used as the inducer of platelet aggregation.

RESULTS AND CONCLUSIONS

N2 can improve the motor function, learning and memory ability in MCAO/R rats while reducing the infarct volume. N2 can inhibit TXA2 formation but promote PGI2, and can inhibit platelet aggregation induced by U46619 and ADP. Further, N2 inhibits thrombosis with a minor adverse effect of bleeding than Clopidogrel. In conclusion, N2 can produce the protective effect on MCAO/R brain injury through inhibiting TXA2 formation, platelet aggregation and thrombosis.

Prevention of cardiovascular diseases

Cardiovascular disease (CVD) is the most important cause of premature death and disability globally. Much is known of the main aetiological risk factors, including elevated blood pressure, dyslipidaemia and smoking, with a raft of additional risks of increasing prevalence, such as obesity and diabetes. Furthermore, some of the most secure evidence-based management strategies in healthcare relate to interventions that modify risk. Yet major gaps remain in the implementation of such evidence, summarized in international guideline recommendations. Some of this gap relates to knowledge deficits amongst clinicians, but also to continued uncertainties over interpretation of the evidence base and areas where data are less available. This article collection in BMC Medicine seeks to offer reflections in each of these areas of uncertainty, spanning issues of better diagnosis, areas of controversy and glimpses of potentially potent future interventions in the prevention of CVD.

Effectiveness of regionalized systems for stroke and myocardial infarction

BACKGROUND

Acute ischemic stroke (AIS) and ST-segment elevation myocardial infarction (STEMI) are ischemic emergencies. Guidelines recommend care delivery within formally regionalized systems of care at designated centers, with bypass of nearby centers of lesser or no designation. We review the evidence of the effectiveness of regionalized systems in AIS and STEMI.

METHODS

Literature was searched using terms corresponding to designation of AIS and STEMI systems and from 2010 to the present. Inclusion criteria included report of an outcome on any dependent variable mentioned in the rationale for regionalization in the guidelines and an independent variable comparing care to a non- or pre-regionalized system. Designation was defined in the AIS case as certification by the Joint Commission as either a primary (PSC) or comprehensive (CSC) stroke center. In the STEMI case, the search was conducted linking "regionalization" and "myocardial infarction" or citation as a model system by any American Heart Association statement.

RESULTS

For AIS, 17 publications met these criteria and were selected for review. In the STEMI case, four publications met these criteria; the search was therefore expanded by relaxing the criteria to include any historical or anecdotal comparison to a pre- or nonregionalized state. The final yield was nine papers from six systems.

CONCLUSION

Although regionalized care results in enhanced process and reduced unadjusted rates of disparity in access and adverse outcomes, these differences tend to become nonsignificant when adjusted for delayed presentation and hospital arrival by means other than emergency medical services. The benefits of regionalized care occur along with a temporal trend of improvement due to uptake of quality initiatives and guideline recommendations by all systems regardless of designation. Further research is justified with a randomized registry or cluster randomized design to support or refute recommendations that regionalization should be the standard of care.

Cost-effectiveness of dabigatran and rivaroxaban compared with warfarin for stroke prevention in patients with atrial fibrillation

PURPOSE

This study aimed to evaluate the cost-effectiveness of dabigatran and rivaroxaban compared with warfarin for the prevention of stroke in patients with atrial fibrillation (AF) in Singapore.

METHODS

A Markov model was constructed to compare the lifetime costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs) of dabigatran 110 and 150 mg, rivaroxaban 20 mg and adjusted-dose warfarin from the perspective of the Singapore healthcare system, using clinical data from published studies, utilities from a patient-reported survey and costs from hospital databases. The target population was a hypothetical cohort of 65-year-old AF patients with no contraindications to anticoagulation.

RESULTS

In the base-case analysis, the QALYs were 8.75 with warfarin, 8.73 with dabigatran 110 mg, 8.82 with dabigatran 150 mg, and 9.33 with rivaroxaban. The costs were Singapore dollar (SG$) 34,648 for warfarin, SG$54,919 for dabigatran 110 mg, SG$50,484 for dabigatran 150 mg and SG$51,975 for rivaroxaban. The ICER of rivaroxaban versus warfarin was SG$29,697 (US$26,727) per QALY. Rivaroxaban and warfarin had extended dominance over the high-dose dabigatran. The low-dose dabigatran was dominated by warfarin. Deterministic sensitivity analyses showed that the ICER of rivaroxaban versus warfarin was sensitive to cost of rivaroxaban and utilities for rivaroxaban and warfarin. Probability sensitivity analysis demonstrated that the probability of rivaroxaban being the optimal choice was 97.8% and 99.5% at a willingness-to-pay threshold of SG$65,000 (US$58,500) and SG$130,000 (US$117,000) per QALY, respectively.

CONCLUSION

Rivaroxaban may be a cost-effective alternative to warfarin for the prevention of stroke in patients with AF in Singapore.

European Primary Care Cardiovascular Society (EPCCS) consensus guidance on stroke prevention in atrial fibrillation (SPAF) in primary care

Background

Atrial fibrillation affects 1–2% of the general population and 10% of those over 75, and is responsible for around a quarter of all strokes. These strokes are largely preventable by the use of anticoagulation therapy, although many eligible patients are not treated. Recent large clinical trials have added to the evidence base on stroke prevention and international clinical guidelines have been updated.

Design

Consensus practical recommendations from primary care physicians with an interest in vascular disease and vascular specialists.

Methods

A focussed all-day meeting, with presentation of summary evidence under each section of this guidance and review of European guidelines on stroke prevention in atrial fibrillation, was used to generate a draft document, which then underwent three cycles of revision and debate before all panel members agreed with the consensus statements.

Results

Six areas were identified that included how to identify patients with atrial fibrillation, how to determine their stroke risk and whether to recommend modification of this risk, and what management options are available, with practical recommendations on maximising benefit and minimising risk if anticoagulation is recommended and the reasons why antiplatelet therapy is no longer recommended. The summary evidence is presented for each area and simple summary recommendations are highlighted, with areas of remaining uncertainty listed.

Conclusions

Atrial fibrillation-related stroke is a major public health priority for most health systems. This practical guidance can assist generalist community physicians to translate the large evidence base for this cause of preventable stroke and implement this at a local level.

Opening the Black Box of Stroke Rehabilitation with Clinical Practice Improvement Methodology

Although stroke survivors are the largest consumer group for postacute rehabilitation services, there has been little quantification of the details of poststroke rehabilitation (PSR), with the major exception of the AHCPR Clinical Practice Guidelines #16 of 1995. The gold standard research methodology of a randomized controlled trial cannot practically encompass PSR. Using clinical practice improvement (CPI), a statistically based, validated research methodology, a mathematical representation of the inpatient stroke rehabilitation experience has been constructed. This article examines the principle aspects of CPI methodology and how it was adapted to a multicenter study of inpatient PSR.

Advances in medical revascularisation treatments in acute ischemic stroke

Urgent reperfusion of the ischaemic brain is the aim of stroke treatment and there has been ongoing research to find a drug that can promote vessel recanalisation more completely and with less side effects. In this review article, the major studies which have validated the use and safety of tPA are discussed. The safety and efficacy of other thrombolytic and anticoagulative agents such as tenecteplase, desmoteplase, ancrod, tirofiban, abciximab, eptifibatide, and argatroban are also reviewed. Tenecteplase and desmoteplase are both plasminogen activators with higher fibrin affinity and longer half-life compared to alteplase. They have shown greater reperfusion rates and improved functional outcomes in preliminary studies. Argatroban is a direct thrombin inhibitor used as an adjunct to intravenous tPA and showed higher rates of complete recanalisation in the ARTTS study with further studies which are now ongoing. Adjuvant thrombolysis techniques using transcranial ultrasound are also being investigated and have shown higher rates of complete recanalisation, for example, in the CLOTBUST study. Overall, development in medical therapies for stroke is important due to the ease of administration compared to endovascular treatments, and the new treatments such as tenecteplase, desmoteplase, and adjuvant sonothrombolysis are showing promising results and await further large-scale clinical trials.

[Epidemiology of cerebral perioperative vascular accidents]

OBJECTIVES

Stroke is a well-described postoperative complication, after carotid and cardiac surgery. On the contrary, few studies are available concerning postoperative stroke in general non-cardiac non-carotid surgery. The high morbid-mortality of stroke justifies an extended analysis of recent literature.

ARTICLE TYPE

Systematic review.

DATA SOURCES

Firstly, Medline and Ovid databases using combination of stroke, cardiac surgery, carotid surgery, general non-cardiac non-carotid surgery as keywords; secondly, national and European epidemiologic databases; thirdly, expert and French health agency recommendations; lastly, reference book chapters.

RESULTS

In cardiac surgery, with an incidence varying from 1.2 to 10% according to procedure complexity, stroke occurs peroperatively in 50% of cases and during the first 48 postoperative hours for the others. The incidence of stroke after carotid surgery is 1 to 20% according to the technique used as well as operator skills. Postoperative stroke is a rare (0.15% as mean, extremes around 0.02 to 1%) complication in general surgery, it occurs generally after the 24-48th postoperative hours, exceptional peroperatively, and 40% of them occurring in the first postoperative week. It concerned mainly aged patient in high-risk surgeries (hip fracture, vascular surgery). Postoperative stroke was associated to an increase in perioperative mortality in comparison to non-postoperative stroke operated patients.

CONCLUSION

Postoperative stroke is a quality marker of the surgical teams' skill and has specific onset time and induces an increase of postoperative mortality.

Left atrial myoxma presenting as headache in the pediatric patient

BACKGROUND

Cardiac myxomas rarely occur in children or adolescents. In addition, it is even more rare for the adolescent patient to present with neurological symptoms only. Early diagnosis is difficult because the symptoms of left atrial myxoma are frequently nonspecific. If delayed or left undiagnosed, severe and fatal complications, such as systemic embolism, heart failure, and pulmonary hypertension, may occur.

CASE REPORT

A 13-year-old girl was admitted to our resuscitation room because of loss of consciousness for the preceding 2 h; she had a longstanding history of headache and dizziness for the previous 18 months. Repeated investigations at her local hospital did not reveal any abnormalities. During this admission, routine chest x-ray study found an abnormal bulge of a segment of the pulmonary artery and elevated cardiac enzymes. Emergency bedside echocardiography was performed and revealed a myxoma in the left atria. Subsequent computed tomography head revealed cardiogenic cerebral embolism. When her condition was stable, the patient was taken to the operating room, where a tumorectomy was performed successfully. The patient was then treated with oral anticoagulants and an uneventful recovery was made. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: In order to avoid delayed diagnosis and treatment of its potentially fatal complications, it is important for the emergency clinician to have a high level of suspicion for a cardiac myxoma when attending to young patients that present with syncope. We therefore recommend that, as routine practice, bedside echocardiography to be carried in the emergency department for young patients that present with syncope.

[GRADE guidelines: 14. Going from evidence to recommendations: the significance and presentation of recommendations]

This article describes the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach to classifying the direction and strength of recommendations. The strength of a recommendation, separated into strong and weak, is defined as the extent to which one can be confident that the desirable effects of an intervention outweigh its undesirable effects. Alternative terms for a weak recommendation include conditional, discretionary, or qualified. The strength of a recommendation has specific implications for patients, the public, clinicians, and policy makers. Occasionally, guideline developers may choose to make "only-in-research" recommendations. Although panels may choose not to make recommendations, this choice leaves those looking for answers from guidelines without the guidance they are seeking. GRADE therefore encourages panels to, wherever possible, offer recommendations.

The PRoFESS trial: future impact on secondary stroke prevention

Patients with transient ischemic attack and ischemic stroke have a high risk of recurrent stroke and death. While aspirin is accepted as standard therapy in these patients, recent trials demonstrate that a combination of aspirin and extended-release dipyridamole or clopidogrel is superior to aspirin monotherapy. Blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers may also reduce recurrent stroke. The ongoing Prevention Regimen for Effectively Avoiding Second Strokes (PRoFESS) trial is designed to evaluate whether extended-release dipyridamole plus aspirin compared with clopidogrel, and whether telmisartan in addition to usual care, in individuals after a stroke, will reduce the risk of further strokes. PRoFESS is a multicenter, randomized, double-blind trial involving 695 sites from 35 countries or regions. The primary outcome for the trial is recurrent stroke, using a time-to-event analysis. Safety is evaluated by assessing the risk of major hemorrhagic and other serious adverse events. With over 20,000 patients randomized, and utilizing a 2 x 2 factorial design, PRoFESS is the largest stroke trial to investigate the prevention of recurrent stroke.

How to Understand Patent Foramen Ovale Clinical Significance: Part I

Patent foramen ovale (PFO) is a remnant of fetal circulation commonly found in healthy population. However, a large number of clinical conditions have been linked to PFO, the most important being ischemic strokes of undetermined cause (cryptogenic strokes) and migraine, especially migraine with aura. Coexistent atrial septal aneurysm, size of PFO, degree of the shunt, shunt at rest, pelvic deep vein thrombosis, and prothrombotic states (G20210A prothrombin gene mutation, Factor V Leiden mutation, MTHFR: C677T, basal homocystine, recent surgery, trauma, or use of contraceptives) could enhance stroke risk in subjects with PFO. Owing to the complexity of this issue, for any individual presenting with a PFO, particularly in the setting of cryptogenic stroke, it is not clear whether the PFO is pathogenically related to the neurological event or an incidental finding. Thus, a heart-brain team, which individually plans the best strategy, in accordance with neuroimaging findings and anatomical characteristics of PFO, is strongly recommended. In the first part of this review, we discuss the embryologic and anatomic features of PFO, the diagnostic techniques for its identification and evaluation, and the relationship between PFO and neurological syndromes. A special attention is made to provide some key points, useful in a daily clinical practice, which summarize how better we understand PFO clinical significance

The brain's heart - therapeutic opportunities for patent foramen ovale (PFO) and neurovascular disease

Patent foramen ovale (PFO), a common congenital cardiac abnormality, is a connection between the right and left atria in the heart. As a "back door to the brain", PFO can serve as a conduit for paradoxical embolism, allowing venous thrombi to enter the arterial circulation, avoiding filtration by the lungs, and causing ischemic stroke. PFO-related strokes affect more than 150,000 people per year in the US, and PFO is present in up to 60% of migraine patients with aura, and in one out of four normal individuals. So, in such a highly prevalent condition, what are the best treatment and prevention strategies? Emerging studies show PFO-related neurovascular disease to be a multi-organ condition with varying individual risk factors that may require individualized therapeutic approaches - opening the field for new pharmacologic and therapeutic targets. The anatomy of PFO suggests that, in addition to thrombi, it can also allow harmful circulatory factors to travel directly from the venous to the arterial circulation, a concept important in finding novel therapeutic targets for PFO-related neurovascular injury. Here, we: 1) review emerging data on PFO-related injuries and clinical trials; 2) discuss potential mechanisms of PFO-related neurovascular disease in the context of multi-organ interaction and heart-brain signaling; and 3) discuss novel therapeutic targets and research frontiers. Clinical studies and molecular mapping of the circulatory landscape of this multi-organ disease will both be necessary in order to better individualize clinical treatment for a condition affecting more than a quarter of the world's population.

The efficacy and adverse reaction of bleeding of clopidogrel plus aspirin as compared to aspirin alone after stroke or TIA: a systematic review

Background and Purpose

Given the high risk of stroke after TIA (transient ischemia attack) or stroke and the adverse reaction of bleeding of antiplatelets, we undertook a meta-analysis, reviewed randomized controlled trials (RCTs) comparing aspirin plus clopidogrel with aspirin alone to determine the efficacy and adverse reaction of bleeding of the two protocols in the prevention of stroke.

Methods

We analyzed the incidences of stroke, bleeding and severe bleeding by using fixed-effect model or random-effect model on the basis of the result of heterogeneity test.

Results

Five qualified RCTs satisfied the inclusion criteria. We found that treatment with aspirin plus clopidogrel was associated with lower incidence of stroke (Risk Ratio (RR), 0.66, 95% confidence interval (CI), 0.47 to 0.93), higher incidence of bleeding (RR, 1.75, 95% CI, 1.48 to 2.05) as compared with aspirin-alone treatment. In terms of severe bleeding, no statistical difference existed between them (RR, 2.21, 95% CI, 0.25 to 19.52).

Conclusion

The combined use of aspirin and clopidogrel is more effective than aspirin alone for patients with previous TIA or stroke for the prevention of stroke, with risk of bleeding being higher. No statistical difference was found in severe bleeding between the two treatment protocols.

Glycosylated hemoglobin A1 predicts risk for symptomatic hemorrhage after thrombolysis for acute stroke

BACKGROUND AND PURPOSE

Symptomatic intracerebral hemorrhage (sICH) is the most feared acute complication after intravenous thrombolysis. The aim of this study was to determine the predictive value of parameters of glycosylated hemoglobin A1 (HbA1c) on sICH.

METHODS

In a retrospective single center series, 1112 consecutive patients treated with thrombolysis were studied. Baseline blood glucose was obtained at admission. HbA1c was determined within hospital stay. A second head computed tomography was obtained after 24 hours or when neurological worsening occurred. Modified Rankin Scale was used to assess outcome at 90 days.

RESULTS

A total of 222 patients (19.9%) had any hemorrhage; 43 of those had sICH (3.9%) per Safe Implementation of Treatments in Stroke definition and 95 (8.5%) per National Institute of Neurological Disorders and Stroke definition; 33.2% of patients had a dependent outcome (modified Rankin Scale score 3-5). In univariate analysis history of diabetes mellitus, HbA1c, blood glucose, and National Institute of Health Stroke Scale score on admission were associated with any hemorrhage and sICH. In multivariate analysis National Institute of Health Stroke Scale score, a history of diabetes mellitus, and HbA1c were predictors of sICH per National Institute of Neurological Disorders and Stroke, and only HbA1c when Safe Implementation of Treatments in Stroke criteria were used.

CONCLUSIONS

In our study, HbA1c turns out to be an important predictor of sICH after thrombolysis for acute stroke. These results suggest that hemorrhage after thrombolysis may be a consequence of long-term vascular injury rather than of acute hyperglycemia, and that HbA1c may be a better predictor than acute blood glucose or a history of diabetes mellitus.

Comparison of susceptibility weighted imaging and TOF-angiography for the detection of Thrombi in acute stroke

BACKGROUND AND PURPOSE

Time-of-flight (TOF) angiography detects embolic occlusion of arteries in patients with acute ischemic stroke due to the absence of blood flow in the occluded vessel. In contrast, susceptibility weighted imaging (SWI) directly enables intravascular clot visualization due to hypointense susceptibility vessel signs (SVS) in the occluded vessel. The aim of this study was to compare the diagnostic accuracy of both methods to determine vessel occlusion in patients with acute stroke.

METHODS

94 patients were included who presented with clinical symptoms for acute stroke and displayed a delay on the time-to-peak perfusion map in the territory of the anterior (ACA), middle (M1, M1/M2, M2/M3) or posterior (PCA) cerebral artery. The frequency of SVS on SWI and vessel occlusion or stenosis on TOF-angiography was compared using the McNemar-Test.

RESULTS

87 of 94 patients displayed a clearly definable SVS on SWI. In 72 patients the SVS was associated with occlusion or stenosis on TOF-angiography. Fifteen patients exclusively displayed SVS on SWI (14 M2/M3, 1 M1), whereas no patient revealed exclusively occlusion or stenosis on TOF-angiography. Sensitivity for detection of embolic occlusion within major vessel segments (M1, M1/M2, ACA, and PCA) did not show any significant difference between both techniques (97% for SWI versus 96% for TOF-angiography) while the sensitivity for detection of embolic occlusion within M2/M3 was significantly different (84% for SWI versus 39% for TOF-angiography, p<0.00012).

CONCLUSIONS

SWI and TOF-angiography provide similar sensitivity for central thrombi while SWI is superior for the detection of peripheral thrombi in small arterial vessel segments.

Prolonged emergency department length of stay is not associated with worse outcomes in patients with intracerebral hemorrhage

BACKGROUND

Prolonged emergency department length of stay (EDLOS) has been associated with worse patient outcomes, longer inpatient stays, and failure to meet quality measures in several acute medical conditions, but these findings have not been consistently reproduced. We performed this study to explore the hypothesis that longer EDLOS would be associated with worse outcomes in a large cohort of patients presenting with spontaneous intracerebral hemorrhage (ICH).

METHODS

We performed a secondary analysis of a prospective cohort of consecutive patients with spontaneous ICH who presented to a single academic referral center from February 2005 to October 2009. The primary exposure variable was EDLOS, and our primary outcome was neurologic status at hospital discharge, measured with a modified Rankin scale (mRS). Secondary outcomes were ICU length of stay, total hospital length of stay, and total hospital costs.

RESULTS

Our cohort included 616 visits of which 42 were excluded, leaving 574 patient encounters for analysis. Median age was 75 years (IQR 63-82), median EDLOS 5.1 h (IQR 3.7-7.1) and median discharge mRS 4 (IQR 3-6). Thirty percent of the subjects died in-hospital. Multivariable proportional odds logistic regression, controlling for age, initial Glasgow Coma Scale, initial hematoma volume, ED occupancy at registration, and the need for intubation or surgical intervention, demonstrated no association between EDLOS and outcome. Furthermore, multivariable analysis revealed no association of increased EDLOS with ICU or hospital length of stay or hospital costs.

CONCLUSION

We found no effect of EDLOS on neurologic outcome or resource utilization for patients presenting with spontaneous ICH.

Clinical Policy: Use of intravenous tPA for the management of acute ischemic stroke in the emergency department

This policy was developed by a joint writing panel of the American College of Emergency Physicians and the American Academy of Neurology. The panel reviewed the literature to derive evidence-based recommendations to help clinicians answer the following critical questions: (1) Is intravenous tissue plasminogen activator (tPA) safe and effective for acute ischemic stroke patients if given within 3 hours of symptom onset? (2) Is intravenous tPA safe and effective for acute ischemic stroke patients treated between 3 to 4.5 hours after symptom onset? Evidence was graded and recommendations were given based on the strength of the available data in the medical literature.

The association between health care spending and quality of care for stroke patients in Japan

Objective

To elucidate the association between health care spending and the quality of care in ischaemic stroke patients in Kyoto prefecture, Japan.

Methods

Municipalities in Kyoto were categorized into quartiles based on age–sex adjusted spending for ischaemic stroke admissions. We used logistic regression models to analyse if patients from lower spending municipalities were less likely to obtain high-quality care. The sample consisted of patients admitted to hospitals in Kyoto prefecture due to ischaemic stroke between February 2009 and March 2010. Quality measures included process indicators such as diagnostic tests, recommended medications, and rehabilitation services; and outcome measures of in-hospital mortality and 30-day mortality rates.

Results

Mean health care spending per patient ranged from 9749 US dollars (USD) to USD 14,303 from the lowest to highest municipalities. Patients from municipalities in the lowest spending quartile were significantly associated with poorer performance in the majority of the process indicators but had similar mortality rates to patients from high-spending municipalities.

Conclusions

Spending was found to be unevenly associated with the quality of care provided and may be indicative of an insufficient provision of resources and specialist expertise in the lower spending municipalities. Further efforts must be made to improve the quality of care in lower spending regions in Japan.

Safety, Tolerability, Pharmacodynamics, and Pharmacokinetics of Rivaroxaban-an Oral, Direct Factor Xa Inhibitor-Are Not Affected by Aspirin

Rivaroxaban (BAY 59-7939) is an oral, direct Factor Xa inhibitor in advanced clinical development for the prevention and treatment of thromboembolic disorders. This was a randomized, 2-way crossover study in healthy male subjects, with an aspirin run-in period, to examine whether aspirin influences the safety, tolerability, pharmacodynamics, and pharmacokinetics of rivaroxaban. All treatments were well tolerated; drug-related adverse events were mild and transient. Aspirin did not alter the effects of rivaroxaban on Factor Xa activity or clotting tests. Platelet aggregation and bleeding time were not affected by rivaroxaban, and rivaroxaban did not influence the effects of aspirin on these parameters to a clinically relevant extent. Aspirin did not affect the pharmacokinetics of rivaroxaban, including the fraction unbound. This study suggests that there is no clinically relevant interaction between rivaroxaban and aspirin and that the 2 drugs could be administered concomitantly at the doses used in this study.