When should an ACE inhibitor be started in chronic HFrEF?

• A. In hemodynamically stable patients to improve survival and symptoms, started at low doses and uptitrated.
• B. Immediate initiation in all patients regardless of stability.
• C. Only after diuretics have been used for 6 weeks.
• D. Only if blood pressure exceeds 140/90.

Answer: (A)

Starting an ACE inhibitor in chronic HFrEF is about using neurohormonal blockade to improve survival and symptoms. The best approach is to begin only after the patient is hemodynamically stable, not during acute decompensation, and to start at a low dose with careful uptitration to the target dose as tolerated. This minimizes risks like hypotension, renal function changes, and hyperkalemia while allowing the patient to achieve the benefits over time. Immediate initiation in every patient isn’t appropriate because instability or low perfusion can make the drug poorly tolerated. There’s no need to wait a fixed period after diuretics, and blood pressure thresholds aren’t the sole gatekeeper—ACE inhibitors can be started even with lower but stable blood pressure if the patient tolerates it, with close monitoring of renal function and potassium.