What is the role of Angiotensin-Converting Enzyme Inhibitors (ACEi) in secondary prevention after a Non-ST-Elevation Myocardial Infarction (NSTEMI)?

From the Guidelines

Angiotensin-converting enzyme inhibitors (ACEIs) are strongly recommended for secondary prevention after a non-ST-elevation myocardial infarction (NSTEMI), particularly for patients with reduced left ventricular ejection fraction (<40%), diabetes, hypertension, or chronic kidney disease, as they provide cardiovascular protection by reducing ventricular remodeling, decreasing afterload, and inhibiting neurohormonal activation, which collectively reduce the risk of heart failure, recurrent MI, and cardiovascular mortality following NSTEMI.

Key Points

• Patients should start an ACEI such as ramipril (2.5-10 mg daily), lisinopril (5-40 mg daily), or perindopril (4-8 mg daily) within 24 hours of stabilization if there are no contraindications, as recommended by the 2011 ACCF/AHA focused update incorporated into the ACC/AHA 2007 guidelines for the management of patients with unstable angina/non-ST-elevation myocardial infarction 1.
• These medications should be continued indefinitely as part of a comprehensive secondary prevention strategy, unless contraindicated, as stated in the 2011 ACCF/AHA focused update 1.
• The initial dose should be low and gradually titrated upward over several weeks to the target dose while monitoring blood pressure, renal function, and potassium levels.
• Common side effects include cough, hypotension, and rarely angioedema, as noted in the 2011 ACCF/AHA focused update 1.
• If a patient cannot tolerate an ACEI due to cough, an angiotensin receptor blocker (ARB) such as valsartan (80-320 mg daily) or candesartan (8-32 mg daily) can be substituted, as recommended by the 2011 ACCF/AHA focused update 1.

Benefits of ACEIs

• Reduce the risk of heart failure, recurrent MI, and cardiovascular mortality following NSTEMI, as supported by the 2011 ACCF/AHA focused update 1.
• Provide cardiovascular protection by reducing ventricular remodeling, decreasing afterload, and inhibiting neurohormonal activation, as noted in the 2011 ACCF/AHA focused update 1.

Special Considerations

• Patients with reduced left ventricular ejection fraction (<40%), diabetes, hypertension, or chronic kidney disease may benefit from ACEIs, as recommended by the 2011 ACCF/AHA focused update 1.
• Patients who are intolerant of ACEIs may be prescribed an ARB as an alternative, as stated in the 2011 ACCF/AHA focused update 1.

From the Research

Role of ACE Inhibitors in Secondary Prevention after NSTEMI

• ACE inhibitors play a crucial role in secondary prevention after a Non-ST-Elevation Myocardial Infarction (NSTEMI) by reducing the risk of major cardiovascular events, such as cardiovascular death, non-fatal MI, and non-fatal ischemic stroke 2, 3, 4.
• The use of ACE inhibitors in patients with NSTEMI has been shown to improve oxidative stress, endothelial and ventricular function, and reduce ventricular remodeling as well as progression of carotid intimal and medial thickening 2.
• Current evidence suggests that ACE inhibitors should be prescribed as early as possible for all patients with acute myocardial infarction, unless contraindicated or not tolerated, and that they should be continued for at least 6 weeks; moreover, because these patients automatically qualify as high-risk individuals, indefinite therapy should be considered 2.
• The TIMI Risk Score for Secondary Prevention (TRS 2°P) score can be used to stratify post-NSTEMI patients for risk of recurrent cardiovascular events and guide the selection of more aggressive secondary prevention therapy, including the use of ACE inhibitors 5.
• ACE inhibitors are recommended as first-line therapy for secondary prevention of cardiovascular outcomes, including MI, stroke, and heart failure, in patients with NSTEMI, unless contraindicated or not tolerated 6, 3, 4.

Benefits of ACE Inhibitors

• ACE inhibitors have been shown to reduce mortality risk, decrease the progression of heart failure, and prevent arrhythmias in patients with NSTEMI 2, 3, 4.
• ACE inhibitors may also exert positive effects by modulating plasminogen activator inhibitor-1, endothelial function, and left ventricular remodeling 3.
• The use of ACE inhibitors in combination with other therapies, such as beta blockers, antiplatelet therapy, and statins, can provide additional benefits in reducing the risk of cardiovascular events in patients with NSTEMI 4.

Clinical Guidelines

• Clinical guidelines recommend the use of ACE inhibitors in all patients with NSTEMI, unless contraindicated or not tolerated, and that they should be continued indefinitely 2, 6, 3, 4.
• The choice of ACE inhibitor should be based on the individual patient's characteristics, such as the presence of heart failure, diabetes, or renal disease 6.
• Angiotensin receptor blockers (ARBs) can be used as an alternative to ACE inhibitors in patients who cannot tolerate them 6, 4.