Spironolactone is used in heart failure with reduced ejection fraction (HFrEF). Its benefit beyond diuresis involves:
- A Beta-1 receptor blockade reducing heart rate and myocardial oxygen demand
- B Angiotensin-II receptor blockade reducing afterload and angiotensin-driven remodeling
- C Aldosterone receptor antagonism preventing myocardial fibrosis, vascular stiffness, and electrolyte abnormalities associated with high aldosterone in heart failure ✓
- D Natriuretic peptide degradation inhibition, increasing ANP/BNP levels
Correct answer: C. Aldosterone receptor antagonism preventing myocardial fibrosis, vascular stiffness, and electrolyte abnormalities associated with high aldosterone in heart failure
Explanation
Aldosterone (inappropriately elevated in HFrEF via RAAS activation) promotes not only sodium retention but also cardiac fibrosis (collagen deposition in the myocardium and vasculature), endothelial dysfunction, baroreceptor impairment, and potassium/magnesium wasting. Spironolactone competitively antagonizes the mineralocorticoid receptor in the heart, vasculature, and kidney, attenuating myocardial fibrosis and remodeling beyond the diuretic effect. This accounts for the mortality reduction in RALES (spironolactone) and EMPHASIS-HF (eplerenone) trials in HFrEF.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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