ACE Inhibitors After Myocardial Infarction
Yes, ACE inhibitors should be used after myocardial infarction and started within the first 24 hours in all patients with anterior MI, heart failure, or ejection fraction ≤40%. 1
Primary Recommendations
ACE inhibitors are Class I indicated (must be used) in the following post-MI patients:
- Anterior location MI 1
- Heart failure present 1
- Left ventricular ejection fraction ≤40% 1
- Hypertension, diabetes, or chronic kidney disease 2
These patients should receive ACE inhibitors within the first 24 hours and continue indefinitely unless contraindicated 1.
Extended Use Beyond High-Risk Patients
It is reasonable (Class IIa) to use ACE inhibitors in ALL patients with STEMI who have no contraindications, even those without the above high-risk features 1. This broader recommendation is supported by evidence showing ACE inhibitors reduce fatal and nonfatal major cardiovascular events independent of other therapies like fibrinolytics, aspirin, and beta blockers 1.
Timing Matters for Maximum Benefit
Start ACE inhibitors within the first 24 hours of MI presentation 1. Early administration (within 48 hours) shows a modest 1-month mortality reduction (OR 0.93), but the benefit amplifies dramatically at 1 year (OR 0.68) 3. Late administration (after 48 hours) still provides significant mortality reduction at 1,2, and 3 years 3.
Contraindications to Avoid
Do not use ACE inhibitors in patients with:
- Hypotension or cardiogenic shock
- Bilateral renal artery stenosis
- History of worsening renal function with ACE inhibitor/ARB exposure
- Renal failure (creatinine >2.5 mg/dL in men, >2.0 mg/dL in women)
- Hyperkalemia (potassium >5.0 mEq/L)
- Drug allergy 1
ARBs as Alternative
For ACE inhibitor-intolerant patients (typically due to cough), use ARBs instead 2, 1. Valsartan has been proven noninferior to captopril in post-MI patients 1. Recent meta-analyses confirm ACE inhibitors and ARBs have equivalent effects on major adverse cardiovascular events, mortality, stroke, and heart failure hospitalization 4, 5, though ACE inhibitors cause more adverse events leading to discontinuation 5.
Add Aldosterone Antagonist for High-Risk Patients
In post-MI patients already on ACE inhibitor and beta-blocker with EF ≤40% who also have diabetes or heart failure, add an aldosterone antagonist (eplerenone) if creatinine and potassium levels are acceptable 2, 1. This combination further reduces mortality 1.
Duration of Therapy
Continue ACE inhibitors indefinitely in patients with reduced ejection fraction, hypertension, diabetes, or chronic kidney disease 2. The role of long-term therapy in low-risk, revascularized patients with preserved function is less certain but generally recommended given the favorable benefit-risk profile 1.