RALES Trial and MRA Monitoring — EECC MCQ

Correct answer: E — The RALES trial demonstrated a 30% mortality reduction with spironolactone 25 mg in HFrEF; monitoring requires serum potassium and creatinine at 1 week, 1 month, then 3-monthly — MRA should be started cautiously in CKD with K⁺ <5.0 mmol/L

The RALES trial (1999) demonstrated that spironolactone 25 mg daily (started at 12.5 mg, uptitrated) reduced all-cause mortality by 30% and HF hospitalisation by 35% in severe HFrEF (NYHA III-IV, LVEF ≤35%). EPHESUS and EMPHASIS-HF subsequently confirmed benefits of eplerenone in post-MI HFrEF and mild HFrEF (NYHA II) respectively. MRAs are a recommended recommendation for HFrEF. Monitoring: K⁺ and creatinine at baseline, 1 week, 1 month after initiation, then every 3-4 months. In CKD stage 3b: start at lower doses, monitor more frequently, use potassium binders (patiromer/SZC) as enablers if K⁺ rises >5.5 mmol/L. Absolute contraindication: K⁺ >5.5 or eGFR <15 mL/min (relative caution at eGFR 15-30). Spironolactone has anti-androgenic effects (gynaecomastia) which eplerenone does not.

Reference: NICE NG106: Chronic heart failure in adults—diagnosis and management: https://www.nice.org.uk/guidance/ng106/chapter/recommendations