From the Guidelines
Management of acute myocardial infarction (MI) requires immediate intervention with a focus on restoring blood flow, limiting myocardial damage, and preventing complications, with primary percutaneous coronary intervention (PCI) being the preferred treatment for patients with ST-segment elevation, as it has been shown to reduce mortality and improve outcomes compared to fibrinolytic therapy 1.
Initial Management
Initial treatment includes:
- Administering aspirin (160 to 325 mg orally) and antiplatelet therapy such as ticagrelor or clopidogrel
- Pain control with morphine (2-4 mg IV) and oxygen therapy for patients with oxygen saturation below 90%
- Sublingual nitroglycerin (unless systolic arterial pressure is less than 90 mm Hg or heart rate is less than 50 or greater than 100 beats per minute)
- A 12-lead electrocardiogram (ECG) should also be performed to diagnose ST-segment elevation or left bundle branch block (LBBB)
Reperfusion Therapy
For STEMI patients, primary PCI should be performed within 90 minutes of first medical contact, or fibrinolytic therapy if PCI is unavailable within 120 minutes 1. Fibrinolytic therapy has been shown to exert a highly significant 21% proportional reduction in 35-day mortality among patients with acute MI and ST elevation 1.
Additional Medications
Additional medications include:
- Beta-blockers (metoprolol 5 mg IV every 5 minutes for 3 doses, then 25-100 mg orally twice daily)
- ACE inhibitors (ramipril 2.5 mg daily, titrated up)
- Statins (atorvastatin 80 mg daily)
- Anticoagulation with heparin or low molecular weight heparin
Post-MI Care
Post-MI care includes:
- Dual antiplatelet therapy for 12 months
- Cardiac rehabilitation
- Lifestyle modifications
- Regular follow-up to monitor cardiac function and adjust medications
This comprehensive approach aims to salvage myocardium, prevent remodeling, and reduce mortality by addressing both the acute thrombotic event and the underlying atherosclerotic disease process. The most recent and highest quality study 1 supports the use of primary PCI as the preferred treatment for patients with ST-segment elevation, and this approach should be prioritized in clinical practice.
From the FDA Drug Label
DOSAGE & ADMINISTRATION Myocardial Infarction Early Treatment During the early phase of definite or suspected acute myocardial infarction, initiate treatment with metoprolol tartrate as soon as possible after the patient’s arrival in the hospital. In patients with acute myocardial infarction, treated with lisinopril, had a higher (9.0% versus 3.7%) incidence of persistent hypotension (systolic blood pressure < 90 mmHg for more than 1 hour) and renal dysfunction (2.4% versus 1. 1%) in-hospital and at six weeks The Gruppo Italiano per lo Studio della Sopravvienza nell’Infarto Miocardico (GISSI-3) study was a multicenter, controlled, randomized, unblinded clinical trial conducted in 19,394 patients with acute myocardial infarction (MI) admitted to a coronary care unit Patients receiving lisinopril (n=9,646), alone or with nitrates, had an 11% lower risk of death (p = 0.04) compared to patients who did not receive lisinopril (n=9,672) (6.4% vs. 7. 2%, respectively) at six weeks
To manage acute MI, the following steps can be taken:
- Initiate treatment with metoprolol tartrate as soon as possible after the patient's arrival in the hospital, in the early phase of definite or suspected acute myocardial infarction.
- Lisinopril can be used in patients with acute myocardial infarction, with a dose of 5 mg within 24 hours of the onset of symptoms, 5 mg after 24 hours, and then 10 mg daily thereafter.
- Monitor patients for persistent hypotension and renal dysfunction when using lisinopril.
- The use of lisinopril and metoprolol tartrate in acute MI has been studied in clinical trials, including the GISSI-3 study 2 and the metoprolol tartrate drug label 3.
- Key considerations include:
- Hemodynamic stability: Ensure the patient is hemodynamically stable before initiating treatment.
- Dose adjustment: Adjust the dose of lisinopril and metoprolol tartrate based on the patient's clinical response and tolerance.
- Monitoring: Closely monitor the patient's blood pressure, heart rate, and electrocardiogram during treatment.
From the Research
Management of Acute Myocardial Infarction
- The management of acute myocardial infarction (MI) involves a comprehensive approach, including diagnosis, treatment, and prevention of complications 4.
- The treatment of acute MI can be organized into three pathways: alleviating acute myocardial ischemia, assessing and treating acute left ventricular dysfunction, and preventing or treating arrhythmias and conduction disturbances 5.
Medical Therapies
- Aspirin is recommended for all patients with suspected acute coronary syndrome (ACS) unless contraindicated, and a second antiplatelet agent (e.g., clopidogrel, ticagrelor, or prasugrel) is also recommended for most patients 6.
- Parenteral anticoagulation with unfractionated heparin, low-molecular-weight heparin, bivalirudin, or fondaparinux is recommended 6.
- Other medical therapies include statins, angiotensin-converting enzyme inhibitors, beta blockers, nitroglycerin, and morphine (to relieve chest pain), and oxygen 6.
Interventional Therapies
- Percutaneous coronary intervention (PCI) with stent placement should be performed as soon as possible for patients with ST-segment elevation myocardial infarction 6.
- Fibrinolytic therapy should be used first if PCI will be delayed for more than 120 minutes 6.
- For non-ST-segment elevation ACS, PCI is recommended, but fibrinolytic therapy is typically not recommended 6.
- Coronary artery bypass grafting (CABG) may be necessary to reestablish coronary artery flow, ideally delayed 3 to 7 days after admission unless the patient has cardiogenic shock, life-threatening arrhythmias, or other high-risk features 6.
Combination Therapies
- Aspirin combined with clopidogrel can effectively reduce the occurrence of re-thrombosis after PCI and improve the recovery of cardiac function after acute operation, with high safety 7.
Timing of Treatment
- The sooner the treatment is initiated, the better the outcome, with a goal of reducing the time from symptom onset to start of specific reperfusion therapy to 2 hours 8.