This is the current release of the guideline.

This guideline updates a previous version: Ryan TJ, Antman EM, Brooks NH, Califf RM, Hillis LD, Hiratzka LF, Rapaport E, Riegel B, Russell RO, Smith EE III, Weaver WD. 1999 update: ACC/AHA guidelines for the management of patients with acute myocardial infarction. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 1999 Sep;34(3):890-911.

ST-elevation myocardial infarction (STEMI)

2004 Guideline

• To assist physicians and other healthcare providers in clinical decision making by describing a range of generally accepted approaches for the diagnosis, management, and prevention of ST-elevation myocardial infarction (STEMI)
• To focus on the numerous advances in the diagnosis and management of patients with ST-elevation myocardial infarction (STEMI) since 1999

2007 Focused Update

To revise the 2004 guideline recommendations that are affected by evolving data and opinion

Management before ST-elevation Myocardial Infarction (STEMI)

1. Identification of patients at risk of STEMI
2. Patient education for early recognition and response to STEMI

Management after Onset of STEMI

1. Management of out-of-hospital cardiac arrest
   • Activation of Emergency Medical System (EMS)
   • Early defibrillation
   • Early advanced cardiac life support
   • Cardiopulmonary resuscitation training program for families

Prehospital Issues

1. Training of emergency medical services systems personnel to respond to patients with chest pain and/or cardiac arrest
2. Prehospital chest pain evaluation and treatment
3. Prehospital fibrinolysis
4. Prehospital destination protocols

Initial Recognition and Management in the Emergency Department (ED)

1. Optimal strategies for ED triage
2. Initial patient evaluation
   • History
   • Physical examination
   • Electrocardiogram
   • Laboratory examinations
   • Measurement of biomarkers of cardiac damage
   • Imaging
3. Management
   • Oxygen
   • Nitroglycerin
   • Analgesia
   • Aspirin
   • Beta-blockers
   • Reperfusion (pharmacological reperfusion, percutaneous coronary intervention, acute surgical perfusion)
   • Ancillary reperfusion therapy, including aspirin, clopidogrel, glycoprotein IIb/IIIa inhibitors
   • Other pharmacological measures, including angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers, strict glucose control (e.g., insulin for people with diabetes), magnesium, calcium channel blockers (e.g., verapamil, diltiazem)

Hospital Management

1. Admission to coronary care unit
2. Admission to step-down unit
3. Early, general measures
   • Monitoring level of activity
   • Diet (e.g., National Cholesterol Education Program [NCEP] Adult Treatment Panel III Therapeutic Lifestyle Changes Diet)
   • Patient education in the hospital setting
   • Analgesia/anxiolytics
4. Risk stratification during early hospital course
5. Medication assessment
6. Estimation of infarct size
   • Electrocardiographic techniques
   • Cardiac biomarker methods
   • Radionuclide imaging
   • Echocardiography
   • Magnetic resonance imaging
7. Management of hemodynamic disturbances
   • Hemodynamic assessment
   • Management of hypotension (e.g., volume loading, vasopressors, intra-aortic balloon counterpulsation)
   • Management of low-output state (e.g., inotropic support, mechanical reperfusion, surgical correction of mechanical complications)
   • Management of pulmonary congestion (e.g., oxygen, morphine sulfate, angiotensin-converting enzyme [ACE] inhibitors, nitrates, diuretics, beta-blockers, aldosterone blockade, echocardiographic assessment, intra-aortic balloon pump)
   • Management of cardiogenic shock (e.g., intra-aortic balloon counterpulsation, early revascularization, fibrinolytic therapy, echocardiographic assessment)
   • Management of right ventricular infarction
   • Management of mechanical causes of heart failure/low-output syndrome (e.g., surgical repairs, intra-aortic balloon counterpulsation)
8. Management of arrhythmias after STEMI, including ventricular arrhythmias, supraventricular arrhythmias/atrial fibrillation, and bradyarrhythmias, atrioventricular, and intraventricular conduction disturbances
   • Use of unsynchronized electric shock
   • Antiarrhythmic drugs
   • Use of synchronized electrical cardioversion
   • Implantable cardioverter defibrillator implantation
   • Use of permanent pacemakers
   • Use of prompt resuscitative measures (chest compressions, atropine, vasopressin, epinephrine, temporary pacing)
9. Management of recurrent chest pain after STEMI
   • Management of pericarditis (e.g., aspirin, anticoagulation, colchicine, acetaminophen, nonsteroidal anti-inflammatory drugs, corticosteroids)
   • Management of recurrent ischemia/infarction (escalation of medical therapy, cardiac catheterization and revascularization as needed, readministration of fibrinolytic therapy)
10. Management of other complications, including ischemic stroke and embolisms (e.g., use of antithrombotic therapy, low-molecular weight heparins, warfarin)
11. Coronary artery bypass graft surgery after STEMI
12. Convalescence, discharge, and post-myocardial infarction care
    • Risk stratification
    • Exercise testing
    • Echocardiographic assessment
    • Exercise myocardial perfusion imaging
    • Assessment of left ventricular function (coronary arteriography, catheterization and revascularization)
    • Assessment of ventricular arrhythmias
13. Secondary prevention
    • Patient education before discharge
    • Lipid management (lipid assessment, diet or drug therapy)
    • Weight management
    • Smoking cessation
    • Antiplatelet therapy
    • Inhibition of renin-angiotensin-aldosterone-system
    • Beta-blockers
    • Blood pressure control
    • Diabetes management
    • Hormone therapy (not recommended)
    • Warfarin therapy
    • Physical activity
    • Antioxidants (not recommended)

Long-Term Management

1. Evaluation of psychosocial impact of STEMI and treatment of psychological symptoms
2. Cardiac rehabilitation
3. Follow-up visit with medical provider

2004 Guideline

The guideline committee conducted comprehensive searching of the scientific and medical literature on acute myocardial infarction (AMI), with special emphasis on ST-elevation myocardial infarction (STEMI). Literature searching was limited to publications on humans and in English from 1990 to 2004. In addition to broad-based searching on MI, specific targeted searches were performed on MI and the following subtopics: 9-1-1, patient delays, emergency medical services (EMS), prehospital fibrinolysis, prehospital electrocardiogram (ECG), emergency department (ED), supplemental oxygen, nitroglycerin, aspirin (acetylsalicylic acid [ASA]), clopidogrel, arrhythmia, reperfusion, fibrinolysis/fibrinolytic therapy, angioplasty, stent, coronary artery bypass graft surgery (CABG), glycoprotein (GP) IIb/IIIa, pericarditis, beta-blockers, ischemia, intra-arterial pressure monitoring, angiotensin-converting enzyme (ACE) inhibitors, amiodarone, procainamide, lidocaine, electrical cardioversion, atropine, temporary pacing, transvenous pacing, permanent pacing, cardiac repair, heparin, low-molecular-weight heparin (LMWH), unfractionated heparin (UFH), ramipril, calcium channel blockers, verapamil, nifedipine, magnesium, stress ECG, invasive strategy, secondary prevention, statins, and cholesterol. The complete list of keywords is beyond the scope of this section. The committee reviewed all compiled reports from computerized searches and conducted additional searching by hand. Literature citations were generally restricted to published manuscripts appearing in journals listed in Index Medicus. Because of the scope and importance of certain ongoing clinical trials and other emerging information, published abstracts were cited when they were the only published information available.

2007 Focused Update

These updated guideline recommendations reflect a consensus of expert opinion following a thorough review that consisted primarily of late-breaking clinical trials identified through a broad-based vetting process as important to the relevant patient population and of other new data deemed to have an impact on patient care. It is important to note that this focused update is not intended to represent an update based on a full literature review from the date of the previous guideline publication. Specific criteria/considerations for inclusion of new data include:

• Publication in a peer-reviewed journal
• Large, randomized, placebo-controlled trial(s)
• Nonrandomized data deemed important on the basis of results that impact current safety and efficacy assumptions
• Strengths/weakness of research methodology and findings
• Likelihood of additional studies influencing current findings
• Impact on current performance measure(s) and/or likelihood of the need to develop new performance measure(s)
• Requests and requirements for review and update from the practice community, key stakeholders, and other sources free of relationships with industry or other potential bias
• Number of previous trials showing consistent results
• Need for consistency with other guidelines or guideline revisions

Late-breaking clinical trials presented at the 2005 and 2006 annual scientific meetings of the American College of Cardiology (ACC), American Heart Association (AHA), and European Society of Cardiology, as well as selected other data, were reviewed by the standing guideline writing committee along with the parent Task Force and other experts to identify those trials and other key data that might impact guidelines recommendations. On the basis of the criteria/considerations noted above, recent trial data and other clinical information were considered important enough to prompt a focused update of the 2004 ACC/AHA Guidelines for the Management of Patients with ST-Elevation Myocardial Infarction.

When considering the new data for this focused update, the writing group faced the task of weighing evidence from studies enrolling large numbers of subjects outside North America. Although noting that practice patterns and the rigor applied to data collection, as well as the genetic makeup of subjects, might influence the observed magnitude of a treatment effect, the writing group believed the data were relevant to formulation of recommendations for management STEMI in North America. The reasons for this decision include that 1) a broad array of management strategies was represented, including substantial proportions of subjects who received some form of reperfusion therapy, 2) concomitant treatments with proven efficacy (e.g., aspirin, beta blockers, inhibitors of the renin-angiotensin-aldosterone system, and statins) were used in the majority of patients, and 3) it was considered an impractical expectation that the tens of thousands of patients with STEMI needed to meet the estimated sample size for contemporary clinical trials be enrolled exclusively at North American sites.

To provide clinicians with a comprehensive set of data, whenever possible the exact event rates in various treatment arms of clinical trials are presented to permit calculation of the absolute risk difference (ARD) and number needed to treat (NNT) or harm (NNH); the relative treatment effects are described either as odds ratio (OR), relative risk (RR), or hazard ratio (HR), depending on the format in the original publication.

Not stated

2004 Guideline

Levels of Evidence

A: Data derived from multiple randomized clinical trials or meta-analyses

B: Data derived from a single randomized trial, or nonrandomized studies

C: Only consensus opinion of experts, case studies, or standard-of-care

2007 Focused Update

Applying Classification of Recommendations and Level of Evidence

*Data available from clinical trials or registries about the usefulness/efficacy in different subpopulations, such as gender, age, history of diabetes, history of prior myocardial infarction, history of heart failure, and prior aspirin use. A recommendation with Level of Evidence B or C does not imply that the recommendation is weak. Many important clinical questions addressed in the guidelines do not lend themselves to clinical trials. Even though randomized trials are not available, there may be a very clear clinical consensus that a particular test or therapy is useful or effective.

NOTE: In 2003, the American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines developed a list of suggested phrases to use when writing recommendations. All guideline recommendations have been written in full sentences that express a complete thought, such that a recommendation, even if separated and presented apart from the rest of the document (including headings above sets of recommendations), would still convey the full intent of the recommendation. It is hoped that this will increase readers' comprehension of the guidelines and will allow queries at the individual recommendation level. (See Table 1 in the Focused Update document for a list of suggested phrases for writing recommendations.)

2004 Guideline

Not stated

2007 Focused Update

In analyzing the data and developing updated recommendations and supporting text, the focused update writing group used evidence-based methodologies developed by the American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines, which are described elsewhere.

The schema for class of recommendation and level of evidence is summarized in "Rating Scheme for the Strength of the Evidence" above and in Table 1 in the focused update document, which also illustrates how the grading system provides estimates of the size of the treatment effect and the certainty of the treatment effect. Note that a recommendation with Level of Evidence B or C does not imply that the recommendation is weak. Many important clinical questions addressed in guidelines do not lend themselves to clinical trials. Although randomized trials may not be available, there may be a very clear clinical consensus that a particular test or therapy is useful and effective. Both the class of recommendation and level of evidence listed in the focused updates are based on consideration of the evidence reviewed in previous iterations of the guidelines as well as the focused update. Of note, the implications of older studies that have informed recommendations but have not been repeated in contemporary settings are carefully considered.

2004 Guideline

Note from the National Guideline Clearinghouse (NGC): The first guideline published by the American College of Cardiology/American Heart Association (ACC/AHA) described the management of patients with acute myocardial infarction (AMI). The subsequent three documents were the Agency for Healthcare and Quality/National Heart, Lung and Blood Institute sponsored guideline on management of unstable angina (UA), the revised/updated ACC/AHA guideline on AMI, and the revised/updated ACC/AHA guideline on unstable angina/non–ST-segment myocardial infarction (UA/NSTEMI). The present guideline is a revision and deals strictly with the management of patients presenting with ST-elevation myocardial infarction (STEMI).

The purpose of the present guideline is to focus on the numerous advances in the diagnosis and management of patients with STEMI since 1999. This is reflected in the changed name of the guideline: "ACC/AHA Guidelines for the Management of Patients with ST-Elevation Myocardial Infarction." It is recognized that there are areas of overlap among this guideline on patients with STEMI, the guideline on patients with UA/NSTEMI, and other guidelines. The guideline committee has handled this overlap by reiterating important concepts and recommendations in this guideline and by providing cross-references to other guidelines.

Writing Committee

Writing committee members were selected with attention to cardiovascular subspecialties, broad geographical representation, and involvement in academic medicine and primary practice, including neurology, emergency medicine, and nursing. The Writing Committee on the Management of Patients with ST-Elevation Myocardial Infarction also included members of the American College of Cardiology Foundation (ACCF) Board of Governors, the American Academy of Family Physicians (AAFP), and the Canadian Cardiovascular Society (CCS).

Writing groups were specifically charged to perform a formal literature review, weigh the strength of evidence for or against a particular treatment or procedure, and include estimates of expected health outcomes where data exist.

Recommendation Development Process

The final recommendations for indications for a diagnostic procedure, a particular therapy, or an intervention in patients with STEMI summarize both clinical evidence and expert opinion. Once recommendations were written, a Classification of Recommendation and Level of Evidence grade was assigned to each recommendation. Classification of Recommendations and Level of Evidence are expressed in the ACC/AHA format.

2007 Focused Update

In an effort to respond more quickly to new evidence, the American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines has created a new "focused update" process to revise the existing guideline recommendations that are affected by evolving data or opinion. Before the initiation of this focused approach, periodic updates and revisions of existing guidelines required up to 3 years to complete. Now, however, new evidence will be reviewed in an ongoing fashion to more efficiently respond to important science and treatment trends that could have a major impact on patient outcomes and quality of care. Evidence will be reviewed at least twice a year, and updates will be initiated on an as needed basis as quickly as possible, while maintaining the rigorous methodology that the ACC and AHA have developed during their more than 20 years of partnership.

For this focused update, all members of the 2004 ST-Elevation Myocardial Infarction (STEMI) writing committee were invited to participate; those who agreed (referred to as the 2007 focused update writing group) were required to disclose all relationships with industry (RWI) relevant to the data under consideration. Focused update writing group members who had no significant relevant RWI wrote the first draft of the focused update; the draft was then reviewed and revised by the full writing group. Each recommendation required a confidential vote by the writing group members before external review of the document. Any writing committee member with a significant (greater than $10,000) relationship with industry relevant to the recommendation was recused from voting on that recommendation.

2004 Guideline

Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is beneficial, useful, and effective.

Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment.

Class IIa: Weight of evidence/opinion is in favor of usefulness/efficacy.

Class IIb: Usefulness/efficacy is less well established by evidence/opinion.

Class III: Conditions for which there is evidence and/or general agreement that a procedure/treatment is not useful/effective and in some cases may be harmful.

2007 Focused Update

See "Rating Scheme for the Strength of the Evidence" field, above.

The guideline developers reviewed published cost analyses.

2004 Guideline

The document was reviewed by three outside reviewers nominated by the American College of Cardiology (ACC) and three outside reviewers nominated by the American Heart Association (AHA), as well as one reviewer each from the American Academy of Family Physicians (AAFP) and the Canadian Cardiovascular Society (CCS), and 58 individual content reviewers.

The document was approved for publication by the governing bodies of the ACC Foundation and the AHA, and endorsed by the CCS.

2007 Focused Update

This document was reviewed by 3 outside reviewers nominated by the ACC and 3 outside reviewers nominated by the AHA, as well as 1 reviewer each from the American Academy of Family Physicians and the Canadian Cardiovascular Society (CCS) and 58 individual content reviewers. All reviewer relationships with industry (RWI) information was collected and distributed to the writing committee and is published in the focused update document.

This document was approved for publication by the governing bodies of the American College of Cardiology Foundation and the American Heart Association and endorsed by the American Academy of Family Physicians and the Canadian Cardiovascular Society.

Note from the National Guideline Clearinghouse (NGC) and the American College of Cardiology/American Heart Association (ACC/AHA) Task Force on Practice Guidelines: In 2007, the ACC/AHA Task Force performed a focused update of the 2004 guidelines for the management of patients with ST-elevation myocardial infarction to revise existing guideline recommendations that are affected by evolving data or opinion. The updated recommendations are presented below, along with the original 2004 recommendations. Sections affected by the focused update are labeled "2007 Update," and new or modified recommendations are labeled as such. All other recommendations remain current in their 2004 form.

The final recommendations for indications for a diagnostic procedure, a particular therapy, or an intervention in patients with ST-elevation myocardial infarction (STEMI) summarize both clinical evidence and expert opinion. Once recommendations were written, a Classification of Recommendation and Level of Evidence grade were assigned to each recommendation. Classification of Recommendations and Level of Evidence are expressed in the ACC/AHA format and are defined at the end of the "Major Recommendations" field.

Management Before STEMI

Identification of Patients at Risk of STEMI

Class I

1. Primary care providers should evaluate the presence and status of control of major risk factors for coronary heart disease (CHD) for all patients at regular intervals (approximately every 3 to 5 years). (Level of Evidence: C)
2. Ten-year risk (National Cholesterol Education Program [NCEP] global risk) of developing symptomatic CHD should be calculated for all patients who have 2 or more major risk factors to assess the need for primary prevention strategies. (Level of Evidence: B)
3. Patients with established CHD should be identified for secondary prevention, and patients with a CHD risk equivalent (e.g., diabetes mellitus, chronic kidney disease, or 10-year risk greater than 20% as calculated by Framingham equations) should receive equally intensive risk factor intervention as those with clinically apparent CHD. (Level of Evidence: A)

Patient Education for Early Recognition and Response to STEMI

Class I

1. Patients with symptoms of STEMI (chest discomfort with or without radiation to the arms[s], back, neck, jaw, or epigastrium; shortness of breath; weakness; diaphoresis; nausea; lightheadedness) should be transported to the hospital by ambulance rather than by friends or relatives. (Level of Evidence: B)
2. Health care providers should actively address the following issues regarding STEMI with patients and their families:
   1. The patient's heart attack risk (Level of Evidence: C)
   2. How to recognize symptoms of STEMI (Level of Evidence: C)
   3. The advisability of calling 9-1-1 if symptoms are unimproved or worsening after 5 minutes, despite feelings of uncertainty about the symptoms and fear of potential embarrassment (Level of Evidence: C)
   4. A plan for appropriate recognition and response to a potential acute cardiac event that includes the phone number to access emergency medical services (EMS), generally 9-1-1. (Level of Evidence: C)

3. Health care providers should instruct patients for whom nitroglycerin has been prescribed previously to take ONE nitroglycerin dose sublingually in response to chest discomfort/pain. If chest discomfort/pain is unimproved or worsening 5 minutes after 1 sublingual nitroglycerin dose has been taken, it is recommended that the patient or family member/friend call 9-1-1 immediately to access EMS. (Level of Evidence: C)

Onset of STEMI

Out-of-Hospital Cardiac Arrest

Class I

1. All communities should create and maintain a strong "Chain of Survival" for out-of-hospital cardiac arrest that includes early access (recognition of the problem and activation of the EMS system by a bystander), early cardiopulmonary resuscitation (CPR), early defibrillation for patients who need it, and early advanced cardiac life support (ACLS). (Level of Evidence: C)
2. Family members of patients experiencing STEMI should be advised to take CPR training and familiarize themselves with the use of an automated external defibrillator (AED). In addition, they should be referred to a CPR training program that has a social support component for family members of post-STEMI patients. (Level of Evidence: B)

Prehospital Issues

Emergency Medical Services (EMS) Systems

Class I

1. All EMS first responders who respond to patients with chest pain and/or suspected cardiac arrest should be trained and equipped to provide early defibrillation. (Level of Evidence: A)
2. All public safety first responders who respond to patients with chest pain and/or suspected cardiac arrest should be trained and equipped to provide early defibrillation with AEDs. (Provision of early defibrillation with AEDs by nonpublic safety first responders is a promising new strategy, but further study is needed to determine its safety and efficacy.) (Level of Evidence: B)
3. Dispatchers staffing 9-1-1 center emergency medical calls should have medical training, should use nationally developed and maintained protocols, and should have a quality-improvement system in place to ensure compliance with protocols. (Level of Evidence: C)

Prehospital Chest Pain Evaluation and Treatment

Class I

1. Prehospital EMS providers should administer 162 to 325 mg of aspirin (chewed) to chest pain patients suspected of having STEMI unless contraindicated or already taken by patient. Although some trials have used enteric-coated aspirin for initial dosing, more rapid buccal absorption occurs with non-enteric-coated formulations. (Level of Evidence: C)

Class IIa

1. It is reasonable for all 9-1-1 dispatchers to advise patients without a history of aspirin allergy who have symptoms of STEMI to chew aspirin (162 to 325 mg) while awaiting arrival of prehospital EMS providers. Although some trials have used enteric-coated aspirin for initial dosing, more rapid buccal absorption occurs with non-enteric-coated formulations. (Level of Evidence: C)
2. It is reasonable that all ACLS providers perform and evaluate 12-lead electrocardiograms (ECGs) routinely on chest pain patients suspected of STEMI. (Level of Evidence: B)
3. If the ECG shows evidence of STEMI, it is reasonable that prehospital ACLS providers review a reperfusion "checklist" and relay the ECG and checklist findings to a predetermined medical control facility and/or receiving hospital. (Level of Evidence: C)

Prehospital Fibrinolysis

Class IIa

1. Establishment of a prehospital fibrinolysis protocol is reasonable in 1) settings in which physicians are present in the ambulance or in 2) well-organized EMS systems with full-time paramedics who have 12-lead ECGs in the field with transmission capability, paramedic initial and ongoing training in ECG interpretation and STEMI treatment, online medical command, a medical director with training/experience in STEMI management, and an ongoing continuous quality-improvement program. (Level of Evidence: B)

Prehospital Destination Protocols

Class I

1. Patients with STEMI who have cardiogenic shock and are less than 75 years of age should be brought immediately or secondarily transferred to facilities capable of cardiac catheterization and rapid revascularization (percutaneous coronary intervention [PCI] or coronary artery bypass graft surgery [CABG]) if it can be performed within 18 hours of onset of shock. (Level of Evidence: A)
2. Patients with STEMI who have contraindications to fibrinolytic therapy should be brought immediately or secondarily transferred promptly (i.e., primary receiving hospital door-to-departure time less than 30 minutes) to facilities capable of cardiac catheterization and rapid revascularization (PCI or CABG). (Level of Evidence: B)
3. Every community should have a written protocol that guides EMS system personnel in determining where to take patients with suspected or confirmed STEMI. (Level of Evidence: C)

Class IIa

1. It is reasonable that patients with STEMI who have cardiogenic shock and are 75 years of age or older be considered for immediate or prompt secondary transfer to facilities capable of cardiac catheterization and rapid revascularization (PCI or CABG) if it can be performed within 18 hours of onset of shock. (Level of Evidence: B)
2. It is reasonable that patients with STEMI who are at especially high risk of dying, including those with severe congestive heart failure (CHF), be considered for immediate or prompt secondary transfer (i.e., primary-receiving hospital door-to-departure time less than 30 minutes) to facilities capable of cardiac catheterization and rapid revascularization (PCI or CABG). (Level of Evidence: B)

Initial Recognition and Management in the Emergency Department (ED)

Optimal Strategies for ED Triage

Class I

1. Hospitals should establish multidisciplinary teams (including primary care physicians, emergency medicine physicians, cardiologists, nurses, and laboratorians) to develop guideline-based, institution-specific written protocols for triaging and managing patients who are seen in the prehospital setting or present to the ED with symptoms suggestive of STEMI. (Level of Evidence: B)

Initial Patient Evaluation

Class I

1. The delay from patient contact with the health care system (typically, arrival at the ED or contact with paramedics) to initiation of fibrinolytic therapy should be less than 30 minutes. Alternatively, if PCI is chosen, the delay from patient contact with the healthcare system (typically, arrival at the ED or contact with paramedics) to balloon inflation should be less than 90 minutes. (Level of Evidence: B)
2. The choice of initial STEMI treatment should be made by the emergency medicine physician on duty based on a predetermined, institution-specific, written protocol that is a collaborative effort of cardiologists (both those involved in coronary care unit management and interventionalists), emergency physicians, primary care physicians, nurses, and other appropriate personnel. For cases in which the initial diagnosis and treatment plan is unclear to the emergency physician or is not covered directly by the agreed-on protocol, immediate cardiology consultation is advisable. (Level of Evidence: C)

History

Class I

1. The targeted history of STEMI patients taken in the ED should ascertain whether the patient has had prior episodes of myocardial ischemia such as stable or unstable angina, MI, CABG, or PCI. Evaluation of the patient's complaints should focus on chest discomfort, associated symptoms, sex- and age-related differences in presentation, hypertension, diabetes mellitus, possibility of aortic dissection, risk of bleeding, and clinical cerebrovascular disease (amaurosis fugax, face/limb weakness or clumsiness, face/limb numbness or sensory loss, ataxia, or vertigo). (Level of Evidence: C)

Physical Examination

Class I

1. A physical examination should be performed to aid in the diagnosis and assessment of the extent, location, and presence of complications of STEMI. (Level of Evidence: C)
2. A brief, focused, and limited neurological examination to look for evidence of prior stroke or cognitive deficits should be performed on STEMI patients before administration of fibrinolytic therapy. (Level of Evidence: C)

Electrocardiogram

Class I

1. A 12-lead ECG should be performed and shown to an experienced emergency physician within 10 minutes of ED arrival for all patients with chest discomfort (or anginal equivalent) or other symptoms suggestive of STEMI. (Level of Evidence: C)
2. If the initial ECG is not diagnostic of STEMI but the patient remains symptomatic, and there is a high clinical suspicion for STEMI, serial ECGs at 5- to 10-minute intervals or continuous 12-lead ST-segment monitoring should be performed to detect the potential development of ST elevation. (Level of Evidence: C)
3. In patients with inferior STEMI, right-sided ECG leads should be obtained to screen for ST elevation suggestive of right ventricular (RV) infarction. (See Section 7.6.6 of the full-text guidelines and the ACC/AHA/ASE 2003 Guideline Update for the Clinical Application of Echocardiography.) (Level of Evidence: B)

Laboratory Examinations

Class I

1. Laboratory examinations should be performed as part of the management of STEMI patients but should not delay the implementation of reperfusion therapy. (Level of Evidence: C)

Biomarkers of Cardiac Damage

Class I

1. Cardiac-specific troponins should be used as the optimum biomarkers for the evaluation of patients with STEMI who have coexistent skeletal muscle injury. (Level of Evidence: C)
2. For patients with ST elevation on the 12-lead ECG and symptoms of STEMI, reperfusion therapy should be initiated as soon as possible and is not contingent on a biomarker assay. (Level of Evidence: C)

Class IIa

1. Serial biomarker measurements can be useful to provide supportive noninvasive evidence of reperfusion of the infarct artery after fibrinolytic therapy in patients not undergoing angiography within the first 24 hours after fibrinolytic therapy. (Level of Evidence: B)

Class III

1. Serial biomarker measurements should not be relied on to diagnose reinfarction within the first 18 hours after the onset of STEMI. (Level of Evidence: C)

Bedside Testing for Serum Cardiac Biomarkers

Class I

1. Although handheld bedside (point-of-care) assays may be used for a qualitative assessment of the presence of an elevated level of a serum cardiac biomarker, subsequent measurements of cardiac biomarker levels should be performed with a quantitative test. (Level of Evidence: B)
2. For patients with ST elevation on the 12-lead ECG and symptoms of STEMI, reperfusion therapy should be initiated as soon as possible and is not contingent on a bedside biomarker assay. (Level of Evidence: C)

Imaging

Class I

1. Patients with STEMI should have a portable chest x-ray, but this should not delay implementation of reperfusion therapy (unless a potential contraindication, such as aortic dissection, is suspected). (Level of Evidence: C)
2. Imaging studies such as a high-quality portable chest x-ray, transthoracic and/or transesophageal echocardiography, and a contrast chest computed tomographic scan or a magnetic resonance imaging (MRI) scan should be used to differentiate STEMI from aortic dissection in patients for whom this distinction is initially unclear. (Level of Evidence: B)

Class IIa

1. Portable echocardiography is reasonable to clarify the diagnosis of STEMI and allow risk stratification of patients with chest pain on arrival at the ED, especially if the diagnosis of STEMI is confounded by left bundle-branch block (LBBB) or pacing, or there is suspicion of posterior STEMI with anterior ST depressions. (See Section 7.6.7 Mechanical Causes of Heart Failure/Low Output Syndrome in the full-text guidelines.) (Level of Evidence: B)

Class III

1. Single-photon emission computed tomography (SPECT) radionuclide imaging should not be performed to diagnose STEMI in patients for whom the diagnosis of STEMI is evident on the ECG. (Level of Evidence: B)

Management

Routine Measures

Oxygen

Class I

1. Supplemental oxygen should be administered to patients with arterial oxygen desaturation (SaO₂ less than 90%). (Level of Evidence: B)

Class IIa

1. It is reasonable to administer supplemental oxygen to all patients with uncomplicated STEMI during the first 6 hours. (Level of Evidence: C)

Nitroglycerin

Class I

1. Patients with ongoing ischemic discomfort should receive sublingual nitroglycerin (0.4 mg) every 5 minutes for a total of 3 doses, after which an assessment should be made about the need for intravenous nitroglycerin. (Level of Evidence: C)
2. Intravenous nitroglycerin is indicated for relief of ongoing ischemic discomfort, control of hypertension, or management of pulmonary congestion. (Level of Evidence: C)

Class III

1. Nitrates should not be administered to patients with systolic blood pressure less than 90 mm Hg or greater than or equal to 30 mm Hg below baseline, severe bradycardia (less than 50 beats per minute [bpm]), tachycardia (more than 100 bpm), or suspected RV infarction. (Level of Evidence: C)
2. Nitrates should not be administered to patients who have received a phosphodiesterase inhibitor for erectile dysfunction within the last 24 hours (48 hours for tadalafil). (Level of Evidence: B)

Analgesia (2007 Update)

Class I

1. Morphine sulfate (2 to 4 mg intravenously [IV] with increments of 2 to 8 mg IV repeated at 5- to 15-minute intervals) is the analgesic of choice for management of pain associated with STEMI. (Level of Evidence: C) (2004 recommendation remains current in 2007 Update)
2. Patients routinely taking nonsteroidal anti-inflammatory drugs (NSAIDs) (except for aspirin), both nonselective as well as COX-2 selective agents, before STEMI should have those agents discontinued at the time of presentation with STEMI because of the increased risk of mortality, reinfarction, hypertension, heart failure, and myocardial rupture associated with their use. (Level of Evidence: C) (New recommendation)

Class III

1. NSAIDs (except for aspirin), both nonselective as well as COX-2 selective agents, should not be administered during hospitalization for STEMI because of the increased risk of mortality, reinfarction, hypertension, heart failure, and myocardial rupture associated with their use. (Level of Evidence: C) (New recommendation)

Aspirin

Class I

1. Aspirin should be chewed by patients who have not taken aspirin before presentation with STEMI. The initial dose should be 162 mg (Level of Evidence: A) to 325 mg (Level of Evidence: C). Although some trials have used enteric-coated aspirin for initial dosing, more rapid buccal absorption occurs with non-enteric-coated aspirin formulations.

Beta-Blockers (2007 Update)

Class I

1. Oral beta-blocker therapy should be initiated in the first 24 hours for patients who do not have any of the following: 1) signs of heart failure, 2) evidence of a low output state, 3) increased risk* for cardiogenic shock, or 4) other relative contraindications to beta blockade (PR interval greater than 0.24 seconds, second- or third-degree heart block, active asthma, or reactive airway disease). (Level of Evidence: B) (Modified recommendation [changed Level of Evidence and text])
2. Patients with early contraindications within the first 24 hours of STEMI should be reevaluated for candidacy for beta-blocker therapy as secondary prevention. (Level of Evidence: C) (2004 recommendation remains current in 2007 update)
3. Patients with moderate or severe left ventricular (LV) failure should receive beta-blocker therapy as secondary p