Clinical policy: critical issues in the evaluation of adult patients with suspected transient ischemic attack in the emergency department.

Definitions for the strength of evidence (Class I-III) and strength of recommendations (A-C) are provided at the end of the "Major Recommendations" field.

1. In adult patients with suspected transient ischemic attack (TIA), are there clinical decision rules that can identify patients at very low short-term risk for stroke who can be safely discharged from the emergency department (ED)?

   Level A recommendations. None specified.

   Level B recommendations. In adult patients with suspected TIA, do not rely on current existing risk stratification instruments (e.g., age, blood pressure, clinical features, duration of TIA and presence of diabetes [ABCD2] score) to identify TIA patients who can be safely discharged from the ED.

   Level C recommendations. None specified.

2. In adult patients with suspected TIA, what imaging can be safely delayed from the initial ED workup?

   Level A recommendations. None specified.

   Level B recommendations. None specified.

   Level C recommendations. (1) The safety of delaying neuroimaging from the initial ED workup is unknown. If noncontrast brain MRI is not readily available, it is reasonable for physicians to obtain a noncontrast head computed tomography (CT) as part of the initial TIA workup to identify TIA mimics (e.g., intracranial hemorrhage, mass lesion). However, noncontrast head CT should not be used to identify patients at high short-term risk for stroke. (2) When feasible, physicians should obtain magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) to identify patients at high short-term risk for stroke. (3) When feasible, physicians should obtain cervical vascular imaging (e.g., carotid ultrasonography, computed tomography angiography [CTA], or magnetic resonance angiography [MRA]) to identify patients at high short-term risk for stroke.

3. In adult patients with suspected TIA, is carotid ultrasonography as accurate as neck CTA or MRA in identifying severe carotid stenosis?

   Level A recommendations. None specified.

   Level B recommendations. None specified.

   Level C recommendations. In adult patients with suspected TIA, carotid ultrasonography may be used to exclude severe carotid stenosis because it has accuracy similar to that of MRA or CTA.

4. In adult patients with suspected TIA, can a rapid ED-based diagnostic protocol safely identify patients at short-term risk for stroke?

   Level A recommendations. None specified.

   Level B recommendations. In adult patients with suspected TIA without high-risk conditions,* a rapid ED-based diagnostic protocol may be used to evaluate patients at short-term risk for stroke.

   Level C recommendations. None specified.

   *High-risk conditions include abnormal initial head CT result (if obtained), suspected embolic source (presence of atrial fibrillation, cardiomyopathy, or valvulopathy), known carotid stenosis, previous large stroke, and crescendo TIA.

Definitions

Strength of Evidence

Literature Classification Schema*

*Some designs (e.g., surveys) will not fit this schema and should be assessed individually.

^†Objective is to measure therapeutic efficacy comparing interventions.

^‡Objective is to determine the sensitivity and specificity of diagnostic tests.

^§Objective is to predict outcome, including mortality and morbidity.

Approach to Downgrading Strength of Evidence*

*See the "Description of Methods Used to Analyze the Evidence" field for more information.

Strength of Recommendations

Strength of recommendations regarding each critical question were made by subcommittee members using results from strength of evidence grading, expert opinion, and consensus among subcommittee members according to the following guidelines:

Level A recommendations. Generally accepted principles for patient care that reflect a high degree of clinical certainty (e.g., based on evidence from 1 or more Class of Evidence I or multiple Class of Evidence II studies).

Level B recommendations. Recommendations for patient care that may identify a particular strategy or range of strategies that reflect moderate clinical certainty (e.g., based on evidence from 1 or more Class of Evidence II studies or strong consensus of Class of Evidence III studies).

Level C recommendations. Recommendations for patient care that are based on evidence from Class of Evidence III studies or, in the absence of any adequate published literature, based on expert consensus. In instances where consensus recommendations are made, "consensus" is placed in parentheses at the end of the recommendation.

There are certain circumstances in which the recommendations stemming from a body of evidence should not be rated as highly as the individual studies on which they are based. Factors such as heterogeneity of results, uncertainty about effect magnitude and consequences, and publication bias, among others, might lead to such a downgrading of recommendations.

An algorithm titled "Example of a Rapid ED-based Diagnostic Protocol" is provided in the original guideline document.

Transient ischemic attack (TIA)

Adults presenting to the emergency department with suspected transient ischemic attack who have had resolution of symptoms

This clinical policy was created after careful review and critical analysis of the medical literature and was based on a systematic review of the literature. Searches of MEDLINE, MEDLINE InProcess, Cochrane, and SCOPUS were performed. All searches were limited to English-language sources, adults, and human studies. Specific key words/phrases, years used in the searches, dates of searches, and study selection are identified under each critical question in the original guideline document. In addition, relevant articles from the bibliographies of included studies and more recent articles identified by committee members and reviewers were included.

Study Selection

Critical Question 1

Three hundred seventy-eight articles were identified in the search. Seventy-two articles were selected from the search results for further review, with 34 studies included for this critical question.

Critical Question 2

Four hundred forty-one articles were identified in the search. Eighty-five articles were selected from the search results for further review, with 13 studies included for this critical question.

Critical Question 3

Three hundred ninety-eight articles were identified in the search. Thirty-four articles were selected from the search results for further review, with 8 studies included for this critical question.

Critical Question 4

Three hundred forty-nine articles were identified in the search. Sixty articles were selected from the search results for further review, with 8 studies included for this critical question.

Strength of Evidence

Literature Classification Schema*

*Some designs (e.g., surveys) will not fit this schema and should be assessed individually.

^†Objective is to measure therapeutic efficacy comparing interventions.

^‡Objective is to determine the sensitivity and specificity of diagnostic tests.

^§Objective is to predict outcome, including mortality and morbidity.

Approach to Downgrading Strength of Evidence*

*See the "Description of Methods Used to Analyze the Evidence" field for more information.

Assessment of Classes of Evidence

All articles used in the formulation of this clinical policy were graded by at least 2 methodologists and assigned a Class of Evidence. Each article was assigned a design class with design 1 representing the strongest study design and subsequent design classes (i.e., design 2, design 3) representing respectively weaker study designs for therapeutic, diagnostic, or prognostic clinical reports, or meta-analyses (see the "Rating Scheme for the Strength of the Evidence" field). Articles were then graded on dimensions related to the study's methodological features, such as randomization processes, blinding, allocation concealment, methods of data collection, outcome measures and their assessment, selection and misclassification biases, sample size, and generalizability. Using a predetermined process related to the study's design, methodological quality, and applicability to the critical question, articles received a final Class of Evidence grade (i.e., Class I, Class II, Class III, or Class X) (see the "Rating Scheme for the Strength of the Evidence" field). Articles identified with fatal flaws or that were ultimately not applicable to the critical question received a Class of Evidence grade "X" and were not used in formulating recommendations for this policy. Grading was done with respect to the specific critical questions; thus, the level of evidence for any one study may vary according to the question for which it is being considered. As such, it was possible for a single article to receive different Classes of Evidence as different critical questions were answered from the same study. Question-specific Classes of Evidence grading may be found in the Evidentiary Table in the original guideline document.

This policy is a product of the American College of Emergency Physicians (ACEP) clinical policy development process, including expert review, and is based on the existing literature; when literature was not available, consensus of emergency physicians was used.

When possible, clinically oriented statistics (e.g., likelihood ratios [LRs], number needed to treat) are presented to help the reader better understand how the results may be applied to the individual patient. For a definition of these statistical concepts, see Appendix C in the original guideline document.

Strength of Recommendations

Strength of recommendations regarding each critical question were made by subcommittee members using results from strength of evidence grading, expert opinion, and consensus among subcommittee members according to the following guidelines:

Level A recommendations. Generally accepted principles for patient care that reflect a high degree of clinical certainty (e.g., based on evidence from 1 or more Class of Evidence I or multiple Class of Evidence II studies).

Level B recommendations. Recommendations for patient care that may identify a particular strategy or range of strategies that reflect moderate clinical certainty (e.g., based on evidence from 1 or more Class of Evidence II studies or strong consensus of Class of Evidence III studies).

Level C recommendations. Recommendations for patient care that are based on evidence from Class of Evidence III studies or, in the absence of any adequate published literature, based on expert consensus. In instances where consensus recommendations are made, "consensus" is placed in parentheses at the end of the recommendation.

There are certain circumstances in which the recommendations stemming from a body of evidence should not be rated as highly as the individual studies on which they are based. Factors such as heterogeneity of results, uncertainty about effect magnitude and consequences, and publication bias, among others, might lead to such a downgrading of recommendations.

The fourth question looks at whether a rapid emergency department (ED)-based diagnostic protocol can be used to safely identify patients at short-term risk for stroke. One of the studies reviewed provided data that using an accelerated diagnostic protocol for transient ischemic attack (TIA) workup has a lower 90-day cost compared with hospital admission without increasing adverse events.

Expert review comments were received from emergency physicians, neurologists, members of the American Heart Association (AHA)/American Stroke Association (ASA), and American College of Emergency Physicians' (ACEP's) Medical Legal Committee. Comments were received during a 60-day open comment period, with notices of the comment period sent in an e-mail to ACEP members, published in EM Today, and posted on the ACEP Web site. The responses were used to further refine and enhance this policy; however, the responses do not imply endorsement of this clinical policy.

This clinical policy was approved by the ACEP Board on June 22, 2016.

This clinical policy was endorsed by the Emergency Nurses Association on July 25, 2016.

The type of supporting evidence is identified and graded for each recommendation (see the "Major Recommendations" field).

Recommendations for question 1 were based on 9 Class II and 25 Class III studies. Recommendations for question 2 were based on 4 Class II studies and 9 Class III studies. Recommendations for question 3 were based on 8 Class III studies. Recommendations for question 4 were based on 5 Class II studies and 3 Class III studies.

See the "Potential Benefits" sections in Appendix D in the original guideline document for information on potential benefits of the specific interventions.

See the "Potential Harms" sections in Appendix D in the original guideline document for information on potential harms of the specific interventions.

An implementation strategy was not provided.

Not applicable: The guideline was not adapted from another source.

The American College of Emergency Physicians (ACEP) was the funding source for this clinical policy.

American College of Emergency Physicians (ACEP) Clinical Policies Subcommittee (Writing Committee) on Suspected Transient Ischemic Attack

ACEP Clinical Policies Committee (Oversight Committee)

Members of the Subcommittee on Suspected Transient Ischemic Attack: Bruce M. Lo, MD, MBA, RDMS (Subcommittee Chair); Christopher R. Carpenter, MD, MSc; Benjamin W. Hatten, MD, MPH; Brian J. Wright, MD, MPH; Michael D. Brown, MD, MSc (Committee Chair)

Members of the Clinical Policies Committee: Michael D. Brown, MD, MSc (Chair 2014-2016); Richard Byyny, MD, MSc (Methodologist); Deborah B. Diercks, MD, MSc; Seth R. Gemme, MD; Charles J. Gerardo, MD, MHS; Steven A. Godwin, MD; Sigrid A. Hahn, MD, MPH; Benjamin W. Hatten, MD, MPH; Jason S. Haukoos, MD, MSc (Methodologist); Graham S. Ingalsbe, MD (EMRA Representative 2015-2016); Amy Kaji, MD, MPH, PhD (Methodologist); Heemun Kwok, MD, MS (Methodologist); Bruce M. Lo, MD, MBA, RDMS; Sharon E. Mace, MD; Devorah J. Nazarian, MD; Jean A. Proehl, RN, MN, CEN, CPEN (ENA Representative 2015-2016); Susan B. Promes, MD, MBA; Kaushal Shah, MD; Richard D. Shih, MD; Scott M. Silvers, MD; Michael D. Smith, MD, MBA; Molly E. W. Thiessen, MD; Christian A. Tomaszewski, MD, MS, MBA; Jonathan H. Valente, MD; Stephen P. Wall, MD, MSc, MAEd (Methodologist); Stephen J. Wolf, MD; Stephen V. Cantrill, MD (Liaison with Quality and Patient Safety Committee); Robert E. O'Connor, MD, MPH (Board Liaison 2010-2016); Rhonda R. Whitson, RHIA, Staff Liaison, Clinical Policies Committee, and TIA Subcommittee; Mary Anne Mitchell, ELS, Staff Liaison, Clinical Policies Committee

Relevant industry relationships: There were no relevant industry relationships disclosed by the subcommittee members for this topic.

Relevant industry relationships are those relationships with companies associated with products or services that significantly impact the specific aspect of disease addressed in the critical question.

This is the current release of the guideline.

This guideline meets NGC's 2013 (revised) inclusion criteria.

Available from the American College of Emergency Physicians (ACEP) Web site .

A summary of this guideline optimized for mobile viewing is available under the CQ tab at the ACEP Web site .

The following are available:

• American College of Emergency Physicians clinical policy development. Irving (TX): American College of Emergency Physicians (ACEP); 3 p. Available from the American College of Emergency Physicians (ACEP) Web site .
• ACEP clinical policy development process. Flow chart. Irving (TX): American College of Emergency Physicians (ACEP); 1 p. Available from the ACEP Web site .

None available

This NGC summary was completed by ECRI Institute on November 17, 2016. The information was verified by the guideline developer on December 19, 2016.

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions. For more information, please refer to the American College of Emergency Physicians (ACEP) Web site .