Myocardial Infarction Guidelines

Updated: Jan 03, 2017
  • Author: A Maziar Zafari, MD, PhD; Chief Editor: Eric H Yang, MD  more...
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Guidelines

Guidelines Summary

The American College of Cardiology Foundation and the American Heart Association (ACCF/AHA) as well as the European Society of Cardiology (ESC) have developed guidelines for management of patients with ST-segment elevation myocardial infarction (STEMI). [2, 4]  

Prehospital and emergency care

The 2013 ACCF/AHA and the 2012 ESC guidelines stress the importance of obtaining a 12-lead electrocardiogram (ECG) in a timely fashion (≤10 mins of presentation) in their recommendations. (Class I, level of evidence B, for both guidelines) [2, 4]  Other ACCF/AHA recommendations for patients with STEMI include those summarized below. [2]

Class I

Level of evidence: A

Reperfusion therapy should be administered to all eligible STEMI patients with symptomatic onset within the previous 12 hours. The recommended reperfusion method is primary PCI when it can be performed expediently by experienced clinicians.

Level of evidence: B

Direct emergency medical services (EMS) transport of STEMI patients to a PCI-capable hospital for primary PCI is recommended, with an ideal first medical contact (FMC)-to-device time system goal of 90 minutes or shorter.

For patients who initially arrive at a non–PCI-capable hospital, immediate transfer to a PCI-capable hospital is recommended, with an FMC-to-device time system goal of 120 minutes or shorter.

In the absence of contraindications and when the anticipated FMC-to-device time exceeds 120 minutes because of unavoidable delays, fibrinolytic therapy should be administered to STEMI patients at non–PCI-capable hospitals. When fibrinolytic therapy is indicated or chosen as the primary reperfusion strategy, it should be administered within 30 minutes of hospital arrival.

Initiate therapeutic hypothermia as soon as possible in comatose STEMI patients with out-of-hospital cardiac arrest caused by ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT), including patients who undergo primary PCI.

For resuscitated out-of-hospital cardiac arrest patients whose initial ECG shows STEMI, immediate angiography and PCI should be performed when indicated.

Class IIa

Primary PCI is the preferred reperfusion strategy for patients with STEMI and symptom onset within the prior 12 to 24 hours in the presence of clinical and/or ECG evidence of ongoing ischemia. (Level of evidence: B)

 

The 2012 ESC guidelines concur with the ACCF/AHA recommendations and additionally recommend routine blood sampling for serum markers in the acute phase. [4]  However, do not delay initiation of reperfusion therapy for the results. (Class I, level of evidence: C)

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Percutaneous Coronary Intervention

Recommendations for percutaneous coronary intervention (PCI) from the 2013 update of the American College of Cardiology/American Heart Association (ACC/AHA) guidelines for management of ST-elevation myocardial infarction (STEMI) [2]  and the 2014 European Society of Cardiology/European Association for Cardio-Thoracic Surgery (ESC/EACTS) guidelines for myocardial revascularization, [109]  include the following:

  • Primary PCI is indicated in patients with ischemic symptoms shorter than 12 hours and contraindications to thrombolytic therapy (irrespective of the time delay from FMC); and in patients with cardiogenic shock or acute severe heart failure, irrespective of the time delay from MI onset (Class I, level of evidence: A)
  • Primary PCI is reasonable in patients with ongoing ischemia 12-24 hours after symptom onset (Class IIb)

2015 ACC/AHA/SCAI guidelines

In 2015 the ACC/AHA and Society for Cardiovascular Angiography and Interventions (ACC/AHA/SCAI) issued revised recommendations for PCI in STEMI patients, as indicated below. [110]

Class IIb

PCI of a noninfarct artery may be considered in selected hemodynamically stable STEMI patients with multivessel disease, either at the time of primary PCI or as a planned staged procedure. (Level of evidence: B-R)

The efficacy of selective and bailout aspiration thrombectomy in patients undergoing primary PCI remains to be established. (Level of evidence: C-LD)

Class III

PCI should not be performed in a noninfarct artery at the time of primary PCI in hemodynamically stable STEMI patients. (Level of evidence: B)

Routine aspiration thrombectomy before primary PCI is not useful. (Level of evidence: A)

2011 ACCF/AHA/SCAI guidelines 

The 2011 ACCF/AHA/SCAI guidelines for PCI provides the following guidance with regard to the selection of  bare-metal stents (BMS) or drug-eluting stents (DES) [111] :

  • Before DES implantation, the need for, and duration of, dual antiplatelet therapy (DAPT) and the ability of the patient to comply with and tolerate DAPT should be discussed with the patient. (Class I, level of evidence: C)
  • DES are useful alternatives to bare-metal stents (BMS) to reduce the risk of restenosis in cases in which there is an elevated risk of restenosis and the patient is likely to be able to tolerate and comply with prolonged DAPT. (Class I, level of evidence A)
  • BMS should be used in patients with high bleeding risk, an inability to comply with 1 year of DAPT, or anticipated invasive or surgical procedures in the next 1 year. (Class I, level of evidence: B)
  • DES implantation should not be performed in patients who are probably unable to tolerate or comply with a prolonged course of DAPT. (Class III, level of evidence: B)

2014 ESC/EACTS recommendations

In its 2014 update, the ESC/EACTS significantly diverged from its previous recommendations and those of ACC/AHA above. It now recommends unrestricted use of new-generation DES, finding that previous concerns regarding the duration of DAPT, and the risks associated with DAPT cessation were unsubstantiated. [109]  Based on evidence of increased efficacy and safety, ESC/EACTS considers new-generation DES the default in all clinical conditions and lesion subsets where PCI is indicated. [109]

2013 ACC/AHA guidelines

In the 2013 ACC/AHA guidelines for management of STEMI, recommendations for antithrombotic therapy in patients undergoing primary PCI include those below [2] :

Class I

  • For supportive anticoagulant therapy: Unfractionated heparin (UFH), with additional boluses as needed to maintain therapeutic activated clotting time levels, accounting for whether a GP IIb/IIIa receptor antagonist has been administered (Level of evidence: C); or bivalirudin with/without UFH prior therapy. (Level of evidence: B)

Class IIa

  • For STEMI patients at high risk of bleeding, bivalirudin monotherapy may be preferred over the combination of UFH and a GP IIb/IIIa receptor antagonist. (Level of evidence: B)

Class III

  • PCI should not be performed with fondaparinux as the sole antithrombin agent. (Level of evidence: B)

 

The 2014 ESC/EACTS guidelines vary from ACC/AHA in that use of both bivalirudin and enoxaparin (with/without GP IIb/IIIa receptor antagonist) are given a class IIa recommendation. [109]

 

For patients undergoing PCI after receiving fibrinolytic therapy, ACC/AHA recommends the following [2] :

Class I

  • For STEMI patients treated with IV UFH: Additional boluses of UFH as needed during PCI, taking into account whether a GP IIb/IIIa receptor antagonist has been administered
  • For STEMI patients treated with enoxaparin: If the last subcutaneous dose was administered within the previous 8 hours, no additional enoxaparin should be given; if the last subcutaneous dose was received 8-12 hours prior to the procedure, an additional dose of enoxaparin 0.3 mg/kg IV  should be administered at the time of PCI.

Class III

  • PCI should not be performed with fondaparinux as the sole antithrombin agent. An additional anticoagulant with anti-IIa activity should be administered because of the risk of catheter thrombosis.

For patients undergoing PCI after receiving fibrinolytic therapy, ACC/AHA recommends the following [2] :

Class I

  • Aspirin should be continued indefinitely. (Level of evidence: A)
  • Clopidogrel 300 mg loading dose should be given before or at the time of PCI to patients who did not receive a previous loading dose and who are undergoing PCI within 24 hours of receiving fibrinolytic therapy. (Level of evidence: C)
  • Clopidogrel 600 mg loading dose should be given before or at the time of PCI to patients who did not receive a previous loading dose and who are undergoing PCI more than 24 hours after receiving fibrinolytic therapy (Level of evidence: C)
  • Administer a 75-mg dose of clopidogrel after PCI (Level of evidence: C)

Class IIa

  • After PCI, aspirin 81 mg per day is preferable to higher maintenance doses. (Level of evidence: B)
  • Prasugrel 60 mg loading dose is reasonable in patients who did not receive a previous loading dose of clopidogrel at the time of administration of a fibrinolytic agent, but it should not be given sooner than 24 hours after administration of a fibrin-specific agent or 48 hours after administration of a non–fibrin-specific agent. (Level of evidence: B)
  • A 10-mg daily maintenance dose of prasugrel is reasonable after PCI. (Level of evidence: B)

Class III

  • Prasugrel is contraindicated in patients with a previous history of stroke or transient ischemic attack. (Level of evidence: B)
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Coronary Artery Bypass Grafting

2014 ACC/AHA guidelines

The 2014 American College of Cardiology/American Heart Association (ACC/AHA) guidelines view coronary artery bypass grafting (CABG) as having a limited role in the acute phase of ST-elevation myocardial infarction (STEMI), but they provide a class I recommendation for CABG in patients whose coronary anatomy is not amenable to percutaneous coronary intervention (PCI) and who have ongoing or recurrent ischemia or cardiogenic shock. [2]

CABG is also recommended (class I) in patients with STEMI at time of operative repair of mechanical defects such as [2] :

  • Ventricular septal defect related to myocardial infarction (MI)
  • Papillary muscle rupture
  • Free wall rupture

Emergency CABG is not recommended in patients with the following conditions [112] :

  • Persistent angina, a small area of viable myocardium, and hemodynamically stable
  • No-reflow state (successful epicardial reperfusion with unsuccessful microvascular reperfusion)

In addition, CABG is not advised for patients with ventricular tachycardia with scar and no evidence of ischemia. [112]

Recommendations for emergency CABG after failed PCI include the following [112] :

  • Ongoing ischemia or threatened occlusion with substantial myocardium at risk (Class I)
  • Hemodynamic compromise without impairment of coagulation and without a previous sternotomy (Class I)
  • Hemodynamic compromise with impairment of coagulation and without a previous sternotomy (Class IIa)
  • Hemodynamic compromise and previous sternotomy (Class IIb)
  • Retrieval of a foreign body (eg, fractured guidewire or stent) in a crucial location (Class IIa)

2015 AHA scientific statement

In 2015, the AHA published a scientific statement on secondary prevention after CABG with the following recommendations [113] :

  • Administer aspirin within 6 hours after CABG in doses of 81 to 325 mg daily. Continue aspirin indefinitely to reduce graft occlusion and adverse cardiac events. (Class I; level of evidence: A)
  • After off-pump CABG, administer dual antiplatelet therapy (DAPT)  for 1 year with combined aspirin (81-162 mg daily) and clopidogrel (75 mg daily) to reduce graft occlusion. (Class I; level of evidence: A)
  • After CABG, clopidogrel 75 mg daily is a reasonable alternative for patients who cannot take aspirin. (Class IIa; level of evidence: C)
  • In patients who present with acute coronary syndrome (ACS), it is reasonable to administer combination antiplatelet therapy with aspirin and either prasugrel or ticagrelor (preferred over clopidogrel) (Class IIa; level of evidence: B)
  • After on-pump CABG, combination therapy with aspirin and clopidogrel for 1 year may be considered in patients without recent ACS, but the benefits are not well established. (Class IIb; level of evidence: A)
  • Warfarin should not be routinely prescribed after CABG for graft patency unless patients have other indications for long-term antithrombotic therapy (such as atrial fibrillation [AF], venous thromboembolism, or a mechanical prosthetic valve). (Class III; level of evidence: A)
  • Antithrombotic alternatives to warfarin (dabigatran, apixaban, rivaroxaban) should not be routinely administered after CABG. (Class III; level of evidence: C)
  • CABG patients should receive statin therapy, starting in the preoperative period and restarting early after surgery. (Class I; level of evidence: A)
  • Administer postoperative high-intensity statin therapy (atorvastatin 40-80 mg, rosuvastatin 20-40 mg) to all CABG patients younger than 75 years. (Class I; level of evidence: A)
  • Administer moderate-intensity statin therapy for those patients who are intolerant of high-intensity statin therapy and for those at greater risk for drug-drug interactions (ie, patients aged >75 years). (Class I; level of evidence: A)
  • Pre- or post-CABG discontinuation of statin therapy is not recommended unless patients have adverse reactions to therapy. (Class III; level of evidence: B)
  • Administer beta-blockers as soon as possible around the time of CABG, in the absence of contraindications, to reduce the risk of postoperative AF and to facilitate blood pressure (BP) control early after surgery. (Class I; level of evidence: A)
  • Administer angiotensin-converting enzyme (ACE) inhibitor therapy after CABG for patients with recent MI, left ventricular (LV) dysfunction, diabetes mellitus, and chronic kidney disease. Carefully consider the patient's renal function in determining the timing of postoperative ACE inhibitor initiation and dose selection. (Class I; level of evidence: B)
  • Routine ACE inhibitor therapy is not recommended early after CABG among patients without a history of recent MI, LV dysfunction, diabetes mellitus, or chronic kidney disease, because it may lead to more harm than benefit and an unpredictable BP response. (Class III; level of evidence: B)
  • Cardiac rehabilitation is recommended for all patients after CABG, with the referral ideally performed early during the surgical hospital stay. (Class I; level of evidence: A)
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Mechanical Circulatory Support

The following organizations released guidelines for the utilization of mechanical circulatory support (MCS):

  • Society for Cardiovascular Angiography and Interventions, American College of Cardiology, Heart Failure Society of America, and Society for Thoracic Surgeons (SCAI/ACC/HFSA/STS)
  • International Society of Heart and Lung Transplantation (ISHLT)
  • American Heart Association (AHA)

2015 SCAI/ACC/HFSA/STS consensus statement

In a 2015 clinical expert consensus statement by the SCAI/ACC/HFSA/STS noted that historically the intraaortic balloon pump (IABP) and extracorporeal membrane oxygenation (ECMO) devices had been the only MCS devices available to clinicians, but axial flow pumps, such as Impella and left atrial to femoral artery bypass pumps, such the TandemHeart have more recently entered clinical practice. The consensus-based recommendations included the following [114] :

  • Percutaneous circulatory assist devices provide superior hemodynamic support compared with pharmacologic therapy, which is particularly apparent for the Impella and Tandem-Heart devices.
  • In those with cardiogenic shock who fail to stabilize or show signs of improvement after initial interventions, consider early placement of an appropriate MCS.
  • In patients with cardiogenic shock, continuous flow pumps (eg, Impella CP, TandemHeart) are more likely to provide clinical benefit than IABP. ECMO may provide particular benefit for patients with impaired respiratory gas exchange.
  • Consider MCS for isolated acute right ventricular failure that is complicated by cardiogenic shock.
  • Consider MCS in the setting of high-risk percutaneous coronary intervention (PCI) (eg, multivessel, left main, or last patent conduit interventions), particularly if the patient is inoperable or has severely decreased ejection fraction or elevated cardiac filling pressures.
  • Consider MCS in patients who fail to wean off of cardiopulmonary bypass.
  • Consider early MCS in patients with acute decompensated heart failure who continue to deteriorate despite initial interventions.
  • MCS may be necessary in the setting of severe biventricular failure via both right- and left-sided percutaneous devices or venoarterial ECMO.

However, there was insufficient evidence regarding the routine use of MCS as an adjunct to primary revascularization to reduce reperfusion injury or infarct size in patients with large acute MI. [114]

2013 ISHLT guidelines

In its 2013 guidelines for mechanical circulatory support, the ISHLT recommended long-term MCS for acute cardiogenic shock in the following patient settings (Class IIa; Level of evidence C) [115] :

  • When ventricular function is deemed unrecoverable or unlikely to recover without long-term device support
  • Severely ill and unable to maintain normal hemodynamics and vital organ function with temporary MCS, or cannot be weaned from temporary MCS or inotropic support
  • Has the capacity for meaningful recovery of end-organ function and quality of life
  • Absence of irreversible end-organ damage

Additional recommendations include [115] :

  • If possible, delay permanent MCS in the setting of an acute infarct involving the left ventricular (LV) apex. (Class IIb; level of evidence C)
  • Perform echocardiography as part of the preoperative assessment and routinely at regular postoperative intervals to evaluate for signs of myocardial recovery and optimal MCS device function. This imaging modality may be used to set optimal pump parameters. (Class I; level of evidence B)
  • In addition, perform echocardiography to evaluate suboptimal MCS device function or in the presence of clinical signs of circulatory dysfunction, including congestive or low output symptoms. (Class I; level of evidence B)
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Dual Antiplatelet Therapy

In 2016, the American College of Cardiology and American Heart Association (ACC/AHA) released updated guidelines on duration of dual antiplatelet therapy (DAPT) in patients with coronary artery disease. [116] In this focused update, the term and acronym DAPT is used to specifically to refer to combination antiplatelet therapy with aspirin and a P2Y12 receptor inhibitor (clopidogrel, prasugrel, or ticagrelor).

2016 ACC/AHA guidelines

Key recommendations for patients with non–ST elevation acute coronary syndrome (NSTE-ACS) or ST-elevation myocardial infarction(STEMI) treated with DAPT are summarized below. [116]

Class I

For all patients treated with DAPT, administer a daily aspirin dose of 81 mg (range, 75-100 mg). (Level of evidence: B-NR)

After bare-metal stent (BMS) or drug-eluting stent (DES) implantation in patients with ACS, P2Y12 inhibitor therapy (clopidogrel, prasugrel, or ticagrelor) should be given for at least 1 year. (Level of evidence: B-R)

For patients who subsequently undergo coronary artery bypass grafting (CABG) after coronary stent implantation, resume P2Y12 inhibitor therapy postoperatively to maintain DAPT until the recommended duration of therapy is completed. (Level of evidence: C-EO)

In ACS patients who undergo CABG, resume P2Y12 inhibitor therapy after CABG to complete 1 year of DAPT therapy. (Level of evidence: C-LD) 

Patients with STEMI treated with DAPT and fibrinolytic therapy should continue P2Y12 inhibitor therapy (clopidogrel) for at least 14 days (level of evidence: A) and, ideally, at least 1 year (level of evidence: C-EO).

Class IIa

After coronary stent implantation in the setting of ACS, ticagrelor is preferred over clopidogrel for maintenance P2Y12 inhibitor therapy. (Level of evidence: B-R)

After coronary stent implantation in ACS patients treated with DAPT who are not at high risk for bleeding complications and who do not have a history of stroke or transient ischemic attack (TIA), it is reasonable to choose prasugrel over clopidogrel for maintenance P2Y12 inhibitor therapy. (Level of evidence: B-R)

Class IIb

In patients treated with coronary stent implantation or fibrinolytic therapy who have tolerated DAPT without a bleeding complication and who are not at high bleeding risk, continuation of DAPT (clopidogrel, prasugrel, or ticagrelor) for longer than 1 year may be reasonable. (Level of evidence: A)

After DES implantation, patients who develop a high risk of bleeding or are at high risk of severe bleeding complication, or who develop significant overt bleeding, discontinuation of P2Y12 inhibitor therapy after 6 months may be reasonable. (Level of evidence: C-LD)

Class III

Prasugrel should not be administered to patients with a previous history of stroke or TIA. (Level of evidence: B-R)

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