From the Guidelines
Patients who have experienced a myocardial infarction (MI) should typically be prescribed a combination of medications for secondary prevention, including antiplatelet therapy, a high-intensity statin, beta-blockers, and an ACE inhibitor or ARB, to reduce the risk of recurrent cardiovascular events and mortality. According to the guidelines, the standard post-MI medication regimen includes antiplatelet therapy with ASA (Aspirin) 81 mg daily indefinitely, plus a P2Y12 inhibitor such as ticagrelor 90 mg twice daily or clopidogrel 75 mg daily for up to 12 months 1. A high-intensity statin like atorvastatin 40-80 mg or rosuvastatin 20-40 mg daily is recommended indefinitely to lower cholesterol and stabilize plaques.
Key Medications
- Beta-blockers such as metoprolol 25-200 mg daily or bisoprolol 2.5-10 mg daily should be continued for at least 3 years, particularly in patients with reduced left ventricular function, as they have been shown to reduce mortality by 23% in long-term trials 1.
- An ACE inhibitor (like ramipril 2.5-10 mg daily or perindopril 4-8 mg daily) or ARB (if ACE inhibitors are not tolerated) is recommended, especially for patients with heart failure, diabetes, or hypertension 1.
- For patients with left ventricular dysfunction (ejection fraction ≤40%), an aldosterone antagonist like eplerenone 25-50 mg daily or spironolactone 25-50 mg daily may be added.
Rationale
The use of these medications is supported by evidence from studies such as the 2017 AHA/ACC clinical performance and quality measures for adults with ST-elevation and non-ST-elevation myocardial infarction, which recommends the use of beta-blockers, ACE inhibitors, and statins in patients with MI 1. Additionally, the 2009 ACC/AHA guideline update for the management of ST-segment elevation myocardial infarction provides guidance on the use of antiplatelet therapy, beta-blockers, and ACE inhibitors in patients with STEMI 1.
Important Considerations
- The choice of medication and dosage should be individualized based on the patient's specific needs and medical history.
- Patients should be closely monitored for potential side effects and interactions between medications.
- Lifestyle modifications, such as a healthy diet, regular exercise, and stress reduction, should also be encouraged to reduce the risk of recurrent cardiovascular events.
From the FDA Drug Label
The 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 It was designed to examine the effects of short-term (6 week) treatment with lisinopril, nitrates, their combination, or no therapy on short-term (6 week) mortality and on long-term death and markedly impaired cardiac function Patients randomized to lisinopril received 5 mg within 24 hours of the onset of symptoms, 5 mg after 24 hours, and then 10 mg daily thereafter. Patients with systolic blood pressure less than 120 mmHg at baseline received 2.5 mg of lisinopril.
According to the provided drug label, medications given to patients post MI following the study protocol are:
- Lisinopril: 5 mg within 24 hours of the onset of symptoms, 5 mg after 24 hours, and then 10 mg daily thereafter, or 2.5 mg for patients with systolic blood pressure less than 120 mmHg at baseline
- Nitrates: alone or in combination with lisinopril
- Thrombolytics (72% of patients)
- Aspirin (84% of patients)
- Beta blocker (31% of patients) 2
From the Research
Medications for Post-MI Patients
According to Canadian guidelines, the following medications are recommended for patients post-myocardial infarction (MI):
- Antiplatelet agents, such as aspirin 3, 4
- Angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) for patients who cannot tolerate ACE inhibitors 3, 4, 5
- Beta-blockers, which decrease mortality and are especially effective in patients with impaired left ventricular (LV) function 3, 4, 6
- Statins for patients with elevated cholesterol levels 3, 4, 5
- Aldosterone blockade for patients with an LV ejection fraction ≤ 40% and either symptomatic heart failure or diabetes 3
- Calcium-channel blockers, restricted to patients with conserved LV function in whom congestion is absent and in whom beta blockers are contraindicated 3
Combination Therapy
A combination therapy with aspirin, an ACE inhibitor, and a statin has been shown to reduce 1-year mortality in patients after acute myocardial infarction (AMI) 5. This combination therapy is often referred to as a polypill approach.
Dosage and Compliance
Studies have shown that patients are likely to adhere to prescribed medications, with high rates of compliance and persistence 7. However, rates of discharge medications are often suboptimal, and dosages may not always be equivalent to those administered in clinical trials 7.