This is the current release of the guideline.

Acute myocardial infarction

Evaluation
Risk Assessment
Treatment

Cardiology
Emergency Medicine

Physicians

• To provide recommendations on indications for emergent fibrinolytic therapy in emergency department (ED) patients with suspected acute myocardial infarction (AMI)
• To address the following critical questions:
  • What are the electrocardiographic indications for emergent fibrinolytic therapy?
  • What are the indications for fibrinolytic therapy in patients being treated at or transferred to a percutaneous coronary intervention center?

Adult patients presenting to the emergency department (ED) with suspected acute myocardial infarction (AMI)

Note: This guideline is not intended for pediatric patients, patients with contraindications to fibrinolytic treatment, or patients in cardiogenic shock.

1. Electrocardiographic indications for fibrinolytic therapy
2. Emergent fibrinolytic therapy
3. Emergent percutaneous coronary intervention therapy
4. Fibrinolytic therapy in patients treated at or being transferred to a center performing percutaneous coronary intervention

• Mortality
• Nonfatal reinfarction, stroke, or cardiogenic shock
• Adverse events

Hand-searches of Published Literature (Primary Sources)
Hand-searches of Published Literature (Secondary Sources)
Searches of Electronic Databases

A writing subcommittee knowledgeable in acute myocardial infarction (AMI)-related literature and clinical guidelines was selected to review the 2000 American College of Emergency Physicians (ACEP) clinical policy in order to select key areas on which to focus this current policy. Two critical questions in the management of patients with AMI of current interest and/or controversy were chosen by the subcommittee:

1. What are the electrocardiographic (ECG) indications for emergent fibrinolytic therapy?
2. What are the indications for fibrinolytic therapy in patients being treated at or transferred to a percutaneous coronary intervention center?

Multiple MEDLINE searches were done. The medical literature was reviewed for articles that pertained to each critical question posed, and pertinent articles were selected. Subcommittee members also supplied articles from bibliographies of initially selected articles or from their own files.

For Question 1, the ACEP Clinical Policies Subcommittee performed a MEDLINE search of clinical trials using a combination of the key words "acute myocardial infarction," "ECG/electrocardiogram," and "thrombolytics/fibrinolytics." A review of potentially relevant abstracts was performed for possible inclusion in this policy. References from the 2000 ACEP clinical policy and the 2004 American College of Cardiology/American Heart Association (ACC/AHA) AMI guidelines were also reviewed for inclusion in this policy. Finally, a detailed review of the Fibrinolytic Therapy Trialists' (FTT) Collaborative Group and the 9 references included in this report was performed.

For Question 2, the ACEP Clinical Policies Subcommittee performed a MEDLINE search utilizing the following key words/phrases in combination with myocardial infarction: "facilitated angioplasty," "facilitated coronary intervention," "transfer," "transport," "rescue PCI," "rescue angioplasty," "prehospital fibrinolytics," and "prehospital thrombolytics." The subcommittee also reviewed all meta-analyses on the use of fibrinolytics and percutaneous coronary intervention (PCI) in the treatment of AMI as well as current guidelines from the ACC/AHA for the treatment of ST-segment elevation myocardial infarction (STEMI). A review of potentially relevant abstracts was performed for possible inclusion in this policy. Chosen papers were subsequently graded by ACEP criteria according to the weight of evidence as it applies to the critical question.

Not stated

Weighting According to a Rating Scheme (Scheme Given)

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 >2 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 "Description of Methods Used to Analyze the Evidence" field for more information.

Review of Published Meta-Analyses
Systematic Review with Evidence Tables

All articles used in the formulation of this clinical policy were graded by at least 2 subcommittee members for strength of evidence and classified by the subcommittee members into 3 classes of evidence on the basis of the design of the study, with design 1 representing the strongest evidence and design 3 representing the weakest evidence for therapeutic, diagnostic, and prognostic clinical reports, respectively. See Appendix A in the original document and the "Rating Scheme for the Strength of the Evidence" field.) Articles were then graded on 6 dimensions thought to be most relevant to the development of a clinical guideline: blinded versus nonblinded outcome assessment, blinded or randomized allocation, direct or indirect outcome measures (reliability and validity), biases (e.g., selection, detection, transfer), external validity (i.e., generalizability), and sufficient sample size. Articles received a final grade (I, II, III) on the basis of a predetermined formula taking into account design and quality of study. (See Appendix B in the original document and the "Rating Scheme for the Strength of the Evidence" field.) Articles with fatal flaws were given an "X" grade and not used in the creation of this policy. Evidence grading was done with respect to the specific data being extracted, and the specific critical question being reviewed. Thus, the level of evidence for any 1 study may vary according to the question, and it is possible for a single article to receive different levels of grading as different critical questions are answered. Question-specific level of evidence grading may be found in the Evidentiary Table included in the original guideline document.

Expert Consensus

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

Clinical findings and strength of recommendations regarding patient management were made according to the following criteria:

Level A recommendations. Generally accepted principles for patient management that reflect a high degree of clinical certainty (i.e., based on strength of evidence Class I or overwhelming evidence from strength of evidence Class II studies that directly address all the issues)

Level B recommendations. Recommendations for patient management that may identify a particular strategy or range of management strategies that reflect moderate clinical certainty (i.e., based on strength of evidence Class II studies that directly address the issue, decision analysis that directly addresses the issue, or strong consensus of strength of evidence Class III studies)

Level C recommendations. Other strategies for patient management that are based on preliminary, inconclusive, or conflicting evidence, or in the absence of any published literature, based on panel consensus

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, strength of prior beliefs, and publication bias, among others, might lead to such a downgrading of recommendations.

A formal cost analysis was not performed and published cost analyses were not reviewed.

External Peer Review
Internal Peer Review

Expert review comments were received from individual emergency physicians and from individual members of the American College of Cardiology and the Society of Chest Pain Centers. Their responses were used to further refine and enhance this policy.

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

What Are the Electrocardiographic (ECG) Indications for Emergent Fibrinolytic Therapy?

Patient Management Recommendations

Level A recommendations. Assess for fibrinolytic therapy in patients with symptoms suggestive of acute myocardial infarction (AMI) and presenting within 12 hours of symptom onset if ECG reveals:

1. ST elevations greater than or equal to 0.1 millivolts (mV) (1 mm) in 2 or more contiguous limb leads or greater than or equal to 0.2 mV (2 mm) in 2 or more contiguous precordial leads lacking features of non-infarction causes of ST-segment elevation (e.g., early repolarization, pericarditis, left ventricular hypertrophy [LVH], incomplete bundle branch block [BBB]).
2. Any type of BBB (right, left, and atypical – new or old) thought to be obscuring ST-segment analysis in patients with clinical presentation strongly suggestive of AMI.

Level B recommendations. Assess for fibrinolytic therapy in patients with symptoms suggestive of AMI and presenting within 12 hours of symptom onset if ECG reveals:

1. ST elevations greater than or equal to 0.1 mV (1 mm) in 2 or more contiguous precordial leads lacking features of non-infarction causes of ST-segment elevation (e.g., early repolarization, pericarditis, LVH, incomplete BBB).
2. New or presumably new left bundle branch block (LBBB).
3. LBBB with concordant ST-segment deviations greater than or equal to 0.1 mV (1 mm) towards the major QRS deflection or discordant ST-segment deviations greater than or equal to 0.5 mV (5 mm) away from the major QRS deflection in 2 or more contiguous leads.
4. ST depressions greater than or equal to 0.2 mV (2 mm) with upright T-waves in 2 or more contiguous anterior precordial leads (V₁ to V₄) in patients with clinical presentation suggestive of AMI involving the posterior left ventricular wall.

Level C recommendations. Assess for fibrinolytic therapy in patients with symptoms suggestive of AMI and presenting within 12 hours of symptom onset if ECG reveals:

1. New or presumably new right bundle branch block (RBBB).
2. RBBB, atypical BBB, or ventricular paced and concordant ST-segment deviations greater than or equal to 0.1 mV (1 mm) towards the major QRS deflection or discordant ST-segment deviations greater than or equal to 0.5 mV (5 mm) away from the major QRS deflection in 2 or more contiguous leads.

What Are the Indications for Fibrinolytic Therapy in Patients Being Treated at or Transferred to a Percutaneous Coronary Intervention (PCI) Center?

Exclusion Criteria: Patients undergoing facilitated PCI with glycoprotein IIb/IIIa platelet inhibitors alone or in combination with half dose fibrinolytics

Patient Management Recommendations

Level A recommendations. None specified.

Level B recommendations. Administer fibrinolytic therapy to patients whose ST-segment elevation myocardial infarction (STEMI) is identified less than 3 hours after symptom onset and expected delay time from initial STEMI identification in the emergency department (ED) until PCI (i.e., balloon time) is greater than 90 minutes.*

Level C recommendations. Administer fibrinolytic therapy to high-risk patients whose STEMI is identified less than 6 hours after symptom onset and expected delay time from initial STEMI identification in the ED until PCI time (i.e., balloon time) is greater than 90 minutes.*

* There is insufficient evidence to make any recommendations in non-high-risk STEMI patients presenting greater than 3 hours after symptom onset, and high-risk patients presenting greater than 6 hours after symptom onset. Time of symptom onset, extent and location of injury, patient risk, and availability of timely PCI need to be taken into consideration.

Definitions:

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 >2 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 "Description of Methods Used to Analyze the Evidence" field for more information.

Strength of Recommendation

Level A recommendations. Generally accepted principles for patient management that reflect a high degree of clinical certainty (i.e., based on strength of evidence Class I or overwhelming evidence from strength of evidence Class II studies that directly address all the issues)

Level B recommendations. Recommendations for patient management that may identify a particular strategy or range of management strategies that reflect moderate clinical certainty (i.e., based on strength of evidence Class II studies that directly address the issue, decision analysis that directly addresses the issue, or strong consensus of strength of evidence Class III studies)

Level C recommendations. Other strategies for patient management that are based on preliminary, inconclusive, or conflicting evidence, or in the absence of any published literature, based on panel consensus

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, strength of prior beliefs, and publication bias, among others, might lead to such a downgrading of recommendations.

None provided

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

• Appropriate utilization of emergent fibrinolytic therapy based on electrocardiographic assessment
• Appropriate utilization of fibrinolytic therapy in patients being treated at or transferred to a percutaneous coronary intervention center

• Current evidence strongly indicates that fibrinolytic therapy should not be used routinely in patients with ST-segment depression on the 12-lead electrocardiogram unless the evaluating physician suspects isolated posterior acute myocardial infarction. Mortality rate may actually be increased by administration of fibrinolytics in this electrocardiographically diverse patient subgroup. In the Fibrinolytic Therapy Trialists' Collaborative Group meta-analysis, mortality in patients with ST-segment depression was 15.2% in the fibrinolytic therapy group versus 13.8% in the control group.
• Adverse effects of fibrinolytic therapy, including bleeding complications.

• 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, strength of prior beliefs, and publication bias, among others, might lead to such a downgrading of recommendations.
• Recommendations offered in this policy are not intended to represent the only diagnostic and management options that the emergency physician should consider. The American College of Emergency Physicians clearly recognizes the importance of the individual physician's judgment. Rather, this guideline defines for the physician those strategies for which medical literature exists to provide support for answers to the crucial questions addressed in this policy.

An implementation strategy was not provided.

Getting Better

Effectiveness
Timeliness

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

2006 Oct

American College of Emergency Physicians - Medical Specialty Society

American College of Emergency Physicians

Clinical Policies Subcommittee on Reperfusion Therapy in Emergency Department Patients with Suspected Acute Myocardial Infarction

ACEP Clinical Policies Committee

Clinical Policies Subcommittee (Writing Committee) on Reperfusion Therapy in Emergency Department Patients with Suspected Acute Myocardial Infarction: Francis M. Fesmire, MD (Subcommittee Chair); William J. Brady, MD; Sigrid Hahn, MD; Wyatt W. Decker, MD; Deborah B. Diercks, MD; Chris A. Ghaemmaghami, MD; Devorah Nazarian, MD; Andy S. Jagoda, MD (Clinical Policies Committee Chair)

American College of Emergency Physicians (ACEP) Clinical Policies Committee (Oversight Committee) Members: Andy S. Jagoda, MD (Chair 2003-2006); Wyatt W. Decker, MD; Jonathan A. Edlow, MD; Francis M. Fesmire, MD; Steven A. Godwin, MD; Sigrid A. Hahn, MD (EMRA Representative 2003-2004, Committee member 2005-2006); John M. Howell, MD; J. Stephen Huff, MD; JoAnn Lazarus, RN, MSN, CEN (ENA Representative 2003); Thomas W. Lukens, MD, PhD; Donna L. Mason, RN, MS, CEN (ENA Representative 2004-2006); Michael Moon, RN, CNS, MSN, CEN (ENA Representative 2004); Anthony M. Napoli, MD (EMRA Representative 2004-2006); Devorah Nazarian, MD; Scott M. Silvers, MD; Edward P. Sloan, MD, MPH; Robert L. Wears, MD, MS (Methodologist); Stephen J. Wolf, MD; John T. Finnell, II, MD, MSc (Liaison for Emergency Medical Informatics Section 2004-2006); Cherri D. Hobgood, MD (Board Liaison 2004-2006); John Skiendzielewski, MD (Board Liaison 2003-2004); Susan M. Nedza, MD, MBA (Board Liaison 2001-2003); Rhonda R. Whitson, RHIA, Staff Liaison, Clinical Policies Committee and Subcommittees

Not stated

This is the current release of the guideline.

None available

None available

This NGC summary was completed by ECRI on November 29, 2006. The information was verified by the guideline developer on March 12, 2007.