Are Angiotensin-Converting Enzyme (ACE) inhibitors given in posterior Myocardial Infarction (MI)?

From the Guidelines

Yes, ACE inhibitors are commonly given in posterior myocardial infarction (MI) to improve morbidity, mortality, and quality of life.

Benefits of ACE Inhibitors in Posterior MI

The use of ACE inhibitors in patients with posterior MI has been supported by several studies, including the AIRE trial, which showed a 27% reduction in relative mortality risk 1.

• ACE inhibitors such as lisinopril, ramipril, or captopril are typically started within 24 hours of a posterior MI in hemodynamically stable patients.
• The usual starting dose is low (e.g., lisinopril 2.5-5 mg daily, ramipril 2.5 mg twice daily, or captopril 6.25 mg three times daily) with gradual titration as tolerated.
• These medications should be continued indefinitely in most patients post-MI.

Monitoring and Potential Interactions

When initiating ACE inhibitors, it's essential to monitor blood pressure, renal function, and potassium levels, particularly in the first few weeks of therapy 1.

• ACE inhibitors are beneficial in posterior MI because they reduce afterload, prevent adverse cardiac remodeling, and improve long-term survival.
• They work by blocking the conversion of angiotensin I to angiotensin II, thereby reducing vasoconstriction and aldosterone secretion.
• This leads to decreased cardiac workload and helps preserve ventricular function after the infarction.

Specific Patient Populations

ACE inhibitors are particularly valuable in patients with reduced left ventricular ejection fraction, heart failure, or anterior MI, but evidence supports their use in all types of MI, including posterior infarctions 1.

• The 2022 study published in Pharmacology and Therapeutics found that ACE inhibitors initiated during the acute phase post-MI and continued for 4–6 weeks reduced 30-day mortality in both sexes 1.
• The 2013 guidelines from the American College of Cardiology Foundation/American Heart Association recommend the use of ACE inhibitors in patients with MI or who recently had an MI and have LV systolic dysfunction 1.

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 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.

Ace inhibitors can be given in posterior MI. The GISSI-3 study 2 shows that patients with acute myocardial infarction, including those with posterior MI, can receive lisinopril, an ace inhibitor. The study administered lisinopril within 24 hours of the onset of symptoms, with a dose of 5 mg, followed by 5 mg after 24 hours, and then 10 mg daily thereafter.

From the Research

Use of ACE Inhibitors in Posterior MI

• ACE inhibitors are used in patients with myocardial infarction, including those with posterior MI, to reduce morbidity and mortality rates 3.
• The use of ACE inhibitors in posterior MI is based on evidence from clinical trials such as SOLVD, SAVE, AIRE, GISSI-III, and ISIS-IV, which demonstrated significant reduction in morbidity and mortality rates in patients with ischemic heart disease and myocardial infarction 3.
• The benefits of ACE inhibitors in posterior MI are thought to be due to their ability to reduce left ventricular remodeling and improve left ventricular function, as well as their anti-atherosclerotic effects and plaque stabilization 4.

Patient Selection and Timing of ACE Inhibitor Therapy

• Patients with depressed systolic function, whether symptomatic or not, should receive a trial of an ACE inhibitor 3.
• Patients with normal systolic function may also benefit from ACE inhibitor therapy, particularly those with large anterior wall myocardial infarction 3.
• The timing of ACE inhibitor therapy is important, with some studies suggesting that early initiation of therapy after myocardial infarction may produce significant benefits 3, 5.
• However, other studies suggest that the benefits of ACE inhibitors may be largely confined to patients with evidence of left ventricular dysfunction, and that careful selection of patients is necessary to maximize benefits and minimize adverse outcomes 6, 7.

Comparison of Different ACE Inhibitors

• Different ACE inhibitors, such as ramipril, perindopril, and zofenopril, may have varying effects on outcomes in patients with posterior MI 5.
• Zofenopril may have advantages over perindopril and ramipril in terms of prevention of negative myocardial remodeling and reduction of major adverse events 5.
• However, more research is needed to fully understand the comparative effects of different ACE inhibitors in patients with posterior MI.