Transient ischemic attack: risk stratification and treatment

Is it possible to prevent cerebral embolization by improving the design and technology of carotid stent implantation?

INTRODUCTION

The prevention of atherosclerotic plaque fragmentation during carotid artery stenting is a fundamental problem in decreasing the risk of disability of patients. The goal of this review is to clarify whether the stent design can have a decisive impact on the rate of intraoperative and postoperative complications.

AREAS COVERED

Different designs of the carotid stents are briefed and the advantages and disadvantages of different stent designs are discussed as well as the results of their clinical use. Various solutions are presented to reduce cerebral embolism during carotid artery stenting.

EXPERT OPINION

There is no conclusive evidence for the benefits of closed cell and hybrid stents. The stent design cannot completely resolve the problem of cerebral embolism. Most of the events of cerebral microembolism occur at the stages of stent delivery rather than protrusion of an atherosclerotic plaque in the long-term follow-up. Most likely, minimization of the risks for periprocedural and postprocedural strokes requires not only the new solutions in stent design as well as the corresponding delivery systems and brain embolic protection systems, but also the new strategies of preprocedural drug stabilization of the atherosclerotic plaque in the carotid artery. Abbreviations: CAS, carotid artery stenting; CE, carotid endarterectomy; DW-MRI, diffusion-weighted magnetic resonance imaging; ECA, external carotid artery; ICA, internal carotid artery; IVUS, intravascular ultrasound examination; OCT, optical coherence tomography.

Emergency Neurological Life Support: Acute Ischemic Stroke

Acute ischemic stroke is a neurological emergency that can be treated with time-sensitive interventions, including both intravenous thrombolysis and endovascular approaches to thrombus removal. Extensive study has demonstrated that rapid, protocolized, assessment and treatment is essential to improving neurological outcome. For this reason, acute ischemic stroke was chosen as an emergency neurological life support protocol. The protocol focuses on the first hour of medical care following the acute onset of a neurological deficit.

Comparison of 2 weight-based heparin dosing nomograms in neurology and vascular surgical patients

BACKGROUND

Unfractionated heparin sodium (UFH) is used in neurology and vascular surgical patients to treat and prevent thromboembolic occlusions and requires weight-based dosing to achieve a therapeutic range; however, the optimal dosing strategy is not known. This study sought to determine whether an intravenous (IV) weight-based UFH dosing nomogram based on an 80-unit/kg bolus and 18-unit · kg(-1) · h(-1) initial infusion rate achieves therapeutic anticoagulation [activated partial thromboplastin time (aPTT), 65-110 seconds] more rapidly than that based on a 60-unit/kg bolus and 12-unit · kg(-1) · h(-1) initial infusion rate in 98 neurology and vascular surgery patients.

METHODS

The study consisted of a retrospective chart review of adults prescribed and administered IV UFH for >6 hours, admitted under the neurology or vascular surgery teams and administered UFH for transient ischemic attack, stroke, acute ischemic limb, or postoperative revascularization.

RESULTS

The time to therapeutic aPTT analysis showed superiority of the higher dose (P = 0.04, log-rank test). At 6 hours, there was a significantly greater proportion of patients within the therapeutic range in the higher dose group (36.0% versus 16.7%, P = 0.03), with fewer subtherapeutic aPTTs (34.0% versus 70.8%, P < 0.001) and more supratherapeutic aPTTs (30.0% versus 12.5%, P = 0.034).

CONCLUSIONS

A weight-based nomogram for IV UFH using an 80-unit/kg bolus and an initial infusion rate of 18 units · kg(-1) · h(-1) showed a more rapid achievement of therapeutic aPTT when compared with a 60:12 dosing nomogram. Future research assessing a 70-unit/kg bolus dose is recommended.

An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging, in patients with transient ischaemic attack and minor stroke: a systematic review, meta-analysis and economic evaluation

BACKGROUND

Patients with transient ischaemic attack (TIA) or minor stroke need rapid treatment of risk factors to prevent recurrent stroke. ABCD2 score or magnetic resonance diffusion-weighted brain imaging (MR DWI) may help assessment and treatment.

OBJECTIVES

Is MR with DWI cost-effective in stroke prevention compared with computed tomography (CT) brain scanning in all patients, in specific subgroups or as 'one-stop' brain-carotid imaging? What is the current UK availability of services for stroke prevention?

DATA SOURCES

Published literature; stroke registries, audit and randomised clinical trials; national databases; survey of UK clinical and imaging services for stroke; expert opinion.

REVIEW METHODS

Systematic reviews and meta-analyses of published/unpublished data. Decision-analytic model of stroke prevention including on a 20-year time horizon including nine representative imaging scenarios.

RESULTS

The pooled recurrent stroke rate after TIA (53 studies, 30,558 patients) is 5.2% [95% confidence interval (CI) 3.9% to 5.9%] by 7 days, and 6.7% (5.2% to 8.7%) at 90 days. ABCD2 score does not identify patients with key stroke causes or identify mimics: 66% of specialist-diagnosed true TIAs and 35-41% of mimics had an ABCD2 score of ≥ 4; 20% of true TIAs with ABCD2 score of < 4 had key risk factors. MR DWI (45 studies, 9078 patients) showed an acute ischaemic lesion in 34.3% (95% CI 30.5% to 38.4%) of TIA, 69% of minor stroke patients, i.e. two-thirds of TIA patients are DWI negative. TIA mimics (16 studies, 14,542 patients) make up 40-45% of patients attending clinics. UK survey (45% response) showed most secondary prevention started prior to clinic, 85% of primary brain imaging was same-day CT; 51-54% of patients had MR, mostly additional to CT, on average 1 week later; 55% omitted blood-sensitive MR sequences. Compared with 'CT scan all patients' MR was more expensive and no more cost-effective, except for patients presenting at > 1 week after symptoms to diagnose haemorrhage; strategies that triaged patients with low ABCD2 scores for slow investigation or treated DWI-negative patients as non-TIA/minor stroke prevented fewer strokes and increased costs. 'One-stop' CT/MR angiographic-plus-brain imaging was not cost-effective.

LIMITATIONS

Data on sensitivity/specificity of MR in TIA/minor stroke, stroke costs, prognosis of TIA mimics and accuracy of ABCD2 score by non-specialists are sparse or absent; all analysis had substantial heterogeneity.

CONCLUSIONS

Magnetic resonance with DWI is not cost-effective for secondary stroke prevention. MR was most helpful in patients presenting at > 1 week after symptoms if blood-sensitive sequences were used. ABCD2 score is unlikely to facilitate patient triage by non-stroke specialists. Rapid specialist assessment, CT brain scanning and identification of serious underlying stroke causes is the most cost-effective stroke prevention strategy.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Emergency medicine and hospital medicine: a call for collaboration

BACKGROUND

In the United States, emergency physicians and hospitalists are increasingly responsible for managing hospitalized patients. These specialists share a common practice space and similar shift work schedules. Together they govern decisions about use of the most expensive care setting in medicine-the hospital.

DISCUSSION

Unfortunately, in most institutions there is little collaboration between emergency physicians and hospitalists, resulting in missed opportunities to improve the quality of care and reduce its cost. In this call to action, we challenge emergency physicians and hospitalists to work together to develop protocols for consistent, evidence-based, and expeditious care of patients admitted from the ED; to collaborate in the care of ED patients who can safely be discharged home; to pursue joint quality, hospital leadership, and cost-effectiveness projects; to work in partnership to assure adequate staffing of hospital-based specialists; and to cooperate in the professional, front-line assessment of clinically and fiscally driven policies aimed at assessing the appropriateness of hospital admissions and readmissions.

SUMMARY

Hospital care is increasingly driven by emergency physicians and hospitalists. We envision a vital role for ongoing collaboration between them in achieving the goals of patient care, education, and quality and safety outcomes.

Emergency medicine and hospital medicine: a call for collaboration

BACKGROUND

In the United States, emergency physicians and hospitalists are increasingly responsible for managing hospitalized patients. These specialists share a common practice space and similar shift work schedules. Together they govern decisions about use of the most expensive care setting in medicine--the hospital.

DISCUSSION

Unfortunately, in most institutions there is little collaboration between emergency physicians and hospitalists, resulting in missed opportunities to improve the quality of care and reduce its cost. In this call to action, we challenge emergency physicians and hospitalists to work together to develop protocols for consistent, evidence-based, and expeditious care of patients admitted from the ED; to collaborate in the care of ED patients who can safely be discharged home; to pursue joint quality, hospital leadership, and cost-effectiveness projects; to work in partnership to assure adequate staffing of hospital-based specialists; and to cooperate in the professional, front-line assessment of clinically and fiscally driven policies aimed at assessing the appropriateness of hospital admissions and readmissions.

SUMMARY

Hospital care is increasingly driven by emergency physicians and hospitalists. We envision a vital role for ongoing collaboration between them in achieving the goals of patient care, education, and quality and safety outcomes.

Critical pathways for post-emergency outpatient diagnosis and treatment: tools to improve the value of emergency care

The decision to admit a patient to the hospital after an emergency department (ED) visit is expensive, frequently not evidence-based, and variable. Outpatient critical pathways are a promising approach to reduce hospital admission after emergency care. Critical pathways exist to risk stratify patients for potentially serious diagnoses (e.g., acute myocardial infarction [AMI]) or evaluate response to therapy (e.g., community-acquired pneumonia) within a short time period (i.e., less than 36 hours), to determine if further hospital-based acute care is needed. Yet, such pathways are variably used while many patients are admitted for conditions for which they could be treated as outpatients. In this article, the authors propose a model of post-ED critical pathways, describe their role in emergency care, list common diagnoses that are amenable to critical pathways in the outpatient setting, and propose a research agenda to address barriers and solutions to increase the use of outpatient critical pathways. If emergency providers are to routinely conduct rapid evaluations in outpatient or observation settings, they must have several conditions at their disposal: 1) evidence-based tools to accurately risk stratify patients for protocolized care, 2) systems of care that reliably facilitate workup in the outpatient setting, and 3) a medical environment conducive to noninpatient pathways, with aligned risks and incentives among patients, providers, and payers. Increased use of critical pathways after emergency care is a potential way to improve the value of emergency care.

Recent Publications on Medications and Pharmacy

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest regarding a broad scope of topics are abstracted monthly.