What medications should be administered for an acute myocardial infarction?

Medications for Acute Myocardial Infarction

All patients with acute myocardial infarction should immediately receive aspirin (162-325 mg non-enteric coated, chewed or crushed), dual antiplatelet therapy with a potent P2Y12 inhibitor (ticagrelor or prasugrel preferred over clopidogrel), and anticoagulation, with the specific regimen determined by whether primary PCI or fibrinolysis is the reperfusion strategy. 1

Immediate Antiplatelet Therapy

Aspirin

• Administer aspirin as soon as possible to all patients without contraindications 1
• Loading dose: 162-325 mg non-enteric coated formulation, chewed or crushed for rapid absorption 1
• Can be given orally or intravenously if unable to swallow 1
• Continue indefinitely at 75-100 mg daily maintenance dose 1

P2Y12 Inhibitors (Dual Antiplatelet Therapy)

• A potent P2Y12 inhibitor (prasugrel or ticagrelor) is recommended before or at the time of PCI, with clopidogrel only if these are unavailable or contraindicated 1
• Continue for 12 months unless excessive bleeding risk exists 1
• This represents a Class I, Level A recommendation from the European Society of Cardiology 1

Anticoagulation Strategy

For Primary PCI

• Enoxaparin (preferred) or unfractionated heparin (UFH) as weight-adjusted bolus followed by infusion 1
• Fondaparinux is NOT recommended for primary PCI 1

For Fibrinolytic Therapy

• Anticoagulation is mandatory in patients receiving fibrinolysis, continued until revascularization or up to 8 days of hospitalization 1
• Enoxaparin IV followed by subcutaneous is preferred over UFH (Class I, Level A) 1
• UFH given as weight-adjusted IV bolus followed by infusion is an alternative (Class I, Level B) 1

Fibrinolytic Therapy (When PCI Unavailable)

• If primary PCI cannot be performed within 120 minutes of STEMI diagnosis, initiate fibrinolytic therapy within 12 hours of symptom onset 1, 2
• Use a fibrin-specific agent: tenecteplase, alteplase, or reteplase (Class I, Level B) 1
• Preferably administer in the pre-hospital setting when fibrinolysis is the chosen strategy 1
• Add clopidogrel to aspirin when fibrinolysis is used (Class I, Level A) 1

Additional Acute Phase Medications

Beta-Blockers

• Oral beta-blockers are indicated in patients with heart failure and/or LVEF <40% unless contraindicated (Class I, Level A) 1
• Intravenous beta-blockers must be avoided in patients with hypotension, acute heart failure, AV block, or severe bradycardia (Class III, Level B) 1

Statins

• Initiate high-intensity statin therapy early 1
• This should begin during hospitalization and continue indefinitely 3, 4

ACE Inhibitors/ARBs

• Recommended in patients with LVEF ≤40%, heart failure, anterior MI, or mitral regurgitation 5, 3, 4
• Should be started early during hospitalization 5, 3

Proton Pump Inhibitors

• A PPI combined with DAPT is recommended in patients at high risk of gastrointestinal bleeding (Class I, Level B) 1

Medications to AVOID

Routine Oxygen

• NOT recommended in patients with oxygen saturation ≥90% (Class III, Level B) 1

Calcium Channel Blockers

• No Class I indications for routine use during or after acute MI 5, 3

Routine Antiarrhythmics

• Not recommended except for beta-blockers 5, 3

Intravenous Magnesium

• No Class I indications for routine use 5

Critical Timing Considerations

• Reperfusion therapy (PCI or fibrinolysis) is indicated in all patients with symptoms <12 hours and persistent ST-elevation (Class I, Level A) 1
• Transfer all patients to PCI-capable center immediately after fibrinolysis (Class I, Level A) 1
• Perform angiography and PCI of the infarct-related artery 2-24 hours after successful fibrinolysis (Class I, Level A) 1

Common Pitfalls to Avoid

• Do not delay aspirin administration while waiting for other medications 1
• Do not use fondaparinux if primary PCI is planned 1
• Do not give IV beta-blockers to hemodynamically unstable patients 1
• Do not withhold fibrinolysis if PCI will be delayed >120 minutes 1, 2
• Do not forget to add clopidogrel when fibrinolysis is the reperfusion strategy 1