What is the recommended treatment for acute myocardial infarction?

Treatment of Acute Myocardial Infarction

Immediate reperfusion therapy—either primary percutaneous coronary intervention (PCI) or fibrinolysis—is the cornerstone of acute MI treatment and must be initiated as rapidly as possible to reduce mortality and preserve myocardial function. 1

Immediate Diagnostic and Supportive Measures

• Obtain a 12-lead ECG within 10 minutes of patient arrival and initiate continuous cardiac monitoring with defibrillator capability. 1, 2
• Administer aspirin 75–100 mg orally or intravenously immediately unless contraindicated. 1, 2
• Avoid routine supplemental oxygen unless peripheral oxygen saturation is <90%. Routine oxygen administration does not improve outcomes and may be harmful. 1, 2

Reperfusion Strategy Selection

Primary PCI (Preferred Method)

Primary PCI is the preferred reperfusion strategy when it can be performed without delay and should be the default approach whenever feasible. 1, 2

• Transfer patients directly to the catheterization laboratory, bypassing the emergency department and intensive care unit. This minimizes door-to-balloon time. 1, 2
• Administer a potent P2Y12 inhibitor (prasugrel or ticagrelor preferred; clopidogrel only if these are unavailable or contraindicated) before or at the time of PCI and continue for 12 months unless bleeding risk is excessive. 1, 2
• Use unfractionated heparin or enoxaparin for anticoagulation during primary PCI. 1, 2
• Do not use fondaparinux for primary PCI—this is contraindicated. 1, 2

Fibrinolytic Therapy (When Primary PCI Cannot Be Performed Timely)

If primary PCI cannot be performed within 120 minutes of STEMI diagnosis, administer fibrinolytic therapy within 12 hours of symptom onset in patients without contraindications. 1

• Initiate fibrinolysis as soon as possible after STEMI diagnosis, preferably in the pre-hospital setting. Every minute of delay increases mortality. 1, 2
• Select a fibrin-specific agent: tenecteplase, alteplase, or reteplase. 1, 2
• Administer oral or intravenous aspirin. 1
• Add clopidogrel to aspirin for dual antiplatelet therapy. 1, 2
• Use enoxaparin (intravenous bolus followed by subcutaneous dosing) for anticoagulation—this is preferred over unfractionated heparin. Weight-adjusted UFH bolus plus infusion is an acceptable alternative. 1, 2

Post-Fibrinolysis Management

All patients receiving fibrinolysis must be transferred immediately to a PCI-capable center. 1, 2

• Perform emergency angiography and PCI without delay if the patient develops heart failure, cardiogenic shock, hemodynamic instability, or electrical instability. 1, 2
• Initiate rescue PCI immediately if fibrinolysis fails (≤50% ST-segment resolution at 60–90 minutes) or if the patient becomes hemodynamically or electrically unstable at any time. 1, 2
• In patients with successful fibrinolysis who remain stable, schedule angiography and PCI of the infarct-related artery between 2 and 24 hours after therapy. 1, 2

Early In-Hospital Pharmacotherapy

Antiplatelet and Anticoagulation Maintenance

• Continue dual antiplatelet therapy (aspirin 75–100 mg daily plus ticagrelor or prasugrel) for 12 months unless bleeding risk is excessive. 1, 2
• Add a proton pump inhibitor in patients at high risk of gastrointestinal bleeding. 1

Cardioprotective Medications

• Initiate high-intensity statin therapy as early as possible and continue long-term unless contraindicated. Target LDL-C <1.8 mmol/L (70 mg/dL) or at least 50% reduction if baseline is 1.8–3.5 mmol/L. 1, 2
• Start an ACE inhibitor within the first 24 hours in patients with heart failure, left ventricular ejection fraction <40%, diabetes, or anterior infarction. 1, 2 An ARB (preferably valsartan) is an alternative for patients intolerant to ACE inhibitors. 1
• Begin oral beta-blocker therapy in patients with heart failure and/or left ventricular ejection fraction <40% unless contraindicated. 1, 2
• Add a mineralocorticoid receptor antagonist in patients with ejection fraction <40% and heart failure or diabetes who are already receiving an ACE inhibitor and beta-blocker, provided there is no renal failure or hyperkalemia. 1

Special Clinical Situations

Cardiac Arrest with STEMI

• Pursue a primary PCI strategy in patients resuscitated from cardiac arrest who show STEMI on ECG. 1, 2
• Initiate targeted temperature management early in resuscitated patients who remain unresponsive. 1, 2
• Do not use pre-hospital cooling with large volumes of cold intravenous fluid immediately after return of spontaneous circulation—this is contraindicated. 1, 2

Late Presentation

• Do not perform routine PCI of an occluded infarct-related artery beyond 48 hours after STEMI onset in asymptomatic patients—this does not improve outcomes. 1

Critical Pitfalls to Avoid

• Do not administer intravenous beta-blockers to patients with hypotension, acute heart failure, high-grade AV block, or severe bradycardia—this can precipitate cardiovascular collapse. 1, 2
• Do not postpone reperfusion therapy for routine echocardiography or other non-essential testing in clear STEMI cases. Time is myocardium. 2
• Do not use fondaparinux as anticoagulation for primary PCI—it is associated with catheter thrombosis. 1, 2
• Do not delay transfer to a PCI-capable center after fibrinolysis for additional diagnostic work-up. 2

Post-Acute Assessment

• Perform routine echocardiography during hospital stay to assess left and right ventricular function, detect early post-MI mechanical complications, and exclude left ventricular thrombus. 1
• Identify smokers and provide repeated advice on cessation with pharmacotherapy (varenicline, bupropion, or nicotine replacement) and behavioral support. 1
• Enroll patients in a cardiac rehabilitation program. 1

The evidence strongly supports this algorithmic approach, with the 2017 ESC STEMI guidelines providing the most comprehensive and current framework for acute MI management. 1 The key to reducing mortality and preserving quality of life is minimizing time to reperfusion—whether by primary PCI or fibrinolysis—and ensuring appropriate adjunctive pharmacotherapy is initiated immediately and continued long-term.