From the Guidelines
For suspected acute myocardial infarction (MI), immediate medical attention is crucial, and initial treatment should include aspirin (if not contraindicated), oxygen, pain relief, and antiplatelet/anticoagulant medications, with the goal of rapid restoration of blood flow to minimize morbidity, mortality, and improve quality of life. The symptoms of acute MI can range from cardiac arrest to patients who are already pain-free at the time of presentation, with the leading symptom being acute chest discomfort described as pain, pressure, tightness, and burning, and chest pain-equivalent symptoms such as dyspnoea, epigastric pain, and pain in the left arm 1.
Diagnosis and Treatment
The diagnosis and treatment of acute MI depend on the electrocardiogram (ECG) findings, with patients differentiated into those with persistent ST-segment elevation and those without 1. Patients with ST-segment elevation should undergo immediate reperfusion by primary percutaneous coronary intervention (PCI) or fibrinolytic therapy if PCI is not available in a timely manner 1. In contrast, patients without ST-segment elevation should not receive thrombolytic therapy, and the benefit of primary PCI in these patients remains uncertain 1.
Initial Management
Initial management in the emergency department should include oxygen, sublingual nitroglycerin (if systolic arterial pressure is not less than 90 mm Hg and heart rate is not less than 50 or greater than 100 beats per minute), adequate analgesia, and aspirin (160 to 325 mg orally) 1. A 12-lead electrocardiogram (ECG) should also be performed to guide further management, including the potential need for thrombolytic therapy or primary percutaneous transluminal coronary angioplasty (PTCA) 1.
Long-term Management
Following the acute phase, patients usually require long-term medications, including antiplatelet agents (aspirin 81mg daily), statins (such as atorvastatin 40-80mg daily), and often beta-blockers and ACE inhibitors, to reduce morbidity and mortality 1. Rehabilitation is crucial for recovery, particularly for patients who have experienced complications such as heart failure or cardiogenic shock 1.
Evidence-Based Practice
The management of acute MI has evolved significantly, with the establishment of the reperfusion era, which includes the widespread use of thrombolytic agents, PTCA, emergency coronary artery bypass graft (CABG) surgery, aspirin, β-adrenoceptor blocking agents, vasodilator therapy, and ACE inhibitors 1. This approach has resulted in an impressive reduction in early and 1-year mortality for patients with acute MI, emphasizing the importance of evidence-based practice in guiding treatment decisions 1.
From the FDA Drug Label
Alteplase is an enzyme (serine protease) that has the property of fibrin-enhanced conversion of plasminogen to plasmin. In patients with acute myocardial infarction administered 100 mg of Activase as an accelerated intravenous infusion over 90 minutes, plasma clearance occurred with an initial half‑life of less than 5 minutes and a terminal half‑life of 72 minutes.
The symptoms of an acute myocardial infarction (MI) are not directly mentioned in the provided drug label. However, the treatment option for acute MI using Alteplase (IV) is mentioned, which involves administering 100 mg as an accelerated intravenous infusion over 90 minutes 2. Key points about this treatment option include:
- Fibrinolysis: Alteplase binds to fibrin in a thrombus and converts the entrapped plasminogen to plasmin, thereby initiating local fibrinolysis.
- Dosage: 100 mg administered over 90 minutes.
- Pharmacokinetics: Plasma clearance occurs with an initial half‑life of less than 5 minutes and a terminal half‑life of 72 minutes.
From the Research
Symptoms of Acute Myocardial Infarction (MI)
- Chest pain or discomfort is a common symptom of acute myocardial infarction 3
- Other symptoms may include shortness of breath, nausea, and fatigue 3
- Some patients may experience painless MI, especially in the postsurgical period 3
Treatment Options for Acute Myocardial Infarction (MI)
- Thrombolytic therapy, including agents such as streptokinase, alteplase, reteplase, and tenecteplase, can help reduce short- and long-term mortality 4
- Primary percutaneous coronary intervention (PCI) has revolutionized the management of patients with acute myocardial infarction, resulting in significant reduction in cardiovascular death 4
- Antiplatelet therapy, including aspirin and P2Y12 receptor inhibitors, is commonly used to reduce thrombotic events in patients with acute coronary syndrome or after PCI [(5,6)]
- Interventions directed toward alleviating acute myocardial ischemia include oxygen, sublingual nitroglycerin, morphine, aspirin, heparin, and intravenous nitroglycerin 3
- Interventions directed toward assessing and treating acute left ventricular dysfunction include invasive hemodynamic monitoring, echocardiography, and pharmacological agents such as diuretics, nitroglycerin, and dobutamine 3
- Interventions directed toward preventing or treating arrhythmias and conduction disturbances include atropine, isoproterenol, beta-blockers, verapamil, digitalis, adenosine, lidocaine, procainamide, bretylium, and amiodarone 3
Platelet Function Testing and Antiplatelet Therapy
- Platelet function testing (PFT) can help identify patients with high platelet reactivity (HPR) who may benefit from intensified antiplatelet therapy 5
- Switching from clopidogrel to ticagrelor can significantly improve 1-year clinical outcomes in STEMI patients with HPR 5
- The use of antiplatelet therapy in patients with acute myocardial infarction complicated by cardiogenic shock is not well studied, and further research is needed to assess the effectiveness of different antiplatelet strategies in this high-risk population 6