Clinical Indications and Cardioprotection
By 2026, the clinical use of ACE inhibitors has expanded into preventative "precision medicine," where they are used to prevent structural damage to the heart and kidneys before symptoms fully manifest.
1. Chronic Heart Failure (HFrEF)
In patients with Heart Failure with reduced Ejection Fraction (HFrEF), ACE inhibitors are a Class I recommendation. They improve survival and reduce hospitalizations by:
Reducing Preload and Afterload: Lowering the pressure the heart must pump against and the volume it must handle.
Inhibiting Remodeling: They prevent the "deleterious remodeling" (stretching and thickening of heart tissue) that occurs after injury, effectively keeping the heart's shape and function intact.
2. Post-Myocardial Infarction (MI)
Starting an ACE inhibitor within 24 hours of a heart attack is a standard protocol. Research in 2025 and 2026 has focused on their antifibrotic effects, showing a $20.8\%$ reduction in serum biomarkers of myocardial fibrosis (scarring). By reducing scarring, these drugs prevent the heart from becoming stiff and inefficient after an attack.
3. Diabetic Nephropathy
ACE inhibitors are uniquely "renoprotective." In the kidneys, Angiotensin II constricts the efferent arteriole more than the afferent arteriole, creating high pressure in the filter (the glomerulus). ACE inhibitors dilate that "exit pipe," lowering the internal pressure of the kidney and slowing the progression of kidney failure in diabetic patients with proteinuria.