Management of patients with ST-elevation myocardial infarction

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

Major Outcomes Considered

• Morbidity and mortality due to ST-elevation myocardial infarction (STEMI)
• Primary prevention of STEMI
• Secondary prevention of cardiovascular events, including second myocardial infarction, sudden cardiac death, recurrent myocardial ischemia, stroke
• Time to treatment
• Incidence of serious bleeding or stroke
• Ejection fraction

Methodology

Methods Used to Collect/Select the Evidence

Hand-searches of Published Literature (Primary Sources)

Hand-searches of Published Literature (Secondary Sources)

Searches of Electronic Databases

Description of Methods Used to Collect/Select the Evidence

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.

Number of Source Documents

Not stated

Methods Used to Assess the Quality and Strength of the Evidence

Weighting According to a Rating Scheme (Scheme Given)

Rating Scheme for the Strength of the Evidence

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

		SIZE OF TREATMENT EFFECT
		CLASS I Benefit >>> Risk Procedure/Treatment SHOULD be performed/ administered	CLASS IIa Benefit >> Risk Additional studies with focused objectives needed IT IS REASONABLE to perform procedure/administer treatment	CLASS IIb Benefit > Risk Additional studies with broad objectives needed; additional registry data would be helpful Procedure/Treatment MAY BE CONSIDERED	CLASS III Risk > Benefit No additional studies needed Procedure/Treatment should NOT be performed/administered SINCE IT IS NOT HELPFUL AND MAY BE HARMFUL
Estimate of Certainty (Precision) of Treatment Effect	LEVEL A Multiple (3–5) population risk strata evaluated* General consistency of direction and magnitude of effect	Recommendation that procedure or treatment is useful/effective Sufficient evidence from multiple randomized trials or meta-analyses	Recommendation in favor of treatment of procedure being useful/effective Some conflicting evidence from multiple randomized trials or meta-analyses	Recommendation's usefulness/efficacy less well established Greater conflicting evidence from multiple randomized trials or meta-analyses	Recommendation that procedure or treatment is not useful/effective and may be harmful Sufficient evidence from multiple randomized trials or meta-analyses
	LEVEL B Limited (2–3) population risk strata evaluated*	Recommendation that procedure or treatment is useful/effective Limited evidence from single randomized trial or nonrandomized studies	Recommendation in favor of treatment of procedure being useful/effective Some conflicting evidence from single randomized trial or nonrandomized studies	Recommendation's usefulness/efficacy less well established Greater conflicting evidence from single randomized trial or nonrandomized studies	Recommendation that procedure or treatment is not useful/effective and may be harmful Limited evidence from single randomized trial or nonrandomized studies
	LEVEL C Very limited (1–2) population risk strata evaluated*	Recommendation that procedure or treatment is useful/effective Only expert opinion, case studies, or standard-of-care	Recommendation in favor of treatment of procedure being useful/effective Only diverging expert opinion, case studies, or standard-of-care	Recommendation's usefulness/efficacy less well established Only diverging expert opinion, case studies, or standard-of-care	Recommendation that procedure or treatment is not useful/effective and may be harmful Only expert opinion, case studies, or standard-of-care

*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.