In the classification of heart failure by ejection fraction, what is the cutoff ejection fraction value that distinguishes HFrEF (heart failure with reduced ejection fraction) from HFmrEF (heart failure with mildly reduced ejection fraction)?

Explanation

## Classification of Heart Failure by Ejection Fraction **Key Point:** The 2022 AHA/ACC/HFSA Heart Failure Guidelines redefined heart failure phenotypes based on left ventricular ejection fraction (LVEF) into four categories: | HF Phenotype | LVEF Range | Key Features | |---|---|---| | **HFrEF** (Reduced) | ≤40% | Systolic dysfunction; most studied; guideline-directed medical therapy well-established | | **HFmrEF** (Mildly Reduced) | 41–49% | Gray zone; intermediate prognosis; emerging evidence for SGLT2i and ACEi/ARB benefit | | **HFpEF** (Preserved) | ≥50% | Diastolic dysfunction; higher prevalence in elderly and women; limited pharmacotherapy | | **HFimpEF** (Improved) | Previously ≤40%, now >40% | Recovery of EF after initial HFrEF diagnosis; prognosis intermediate | **High-Yield:** The boundary between HFrEF and HFmrEF is **40%** — this is a frequently tested cutoff in NEET PG. An LVEF of exactly 40% is classified as HFrEF (≤40%). **Mnemonic:** **RAMP** — **R**educed (≤40%), **A**lmost normal (41–49%), **M**ore (≥50%), **P**reviously reduced (improved). ### Clinical Significance 1. **HFrEF (≤40%):** - Systolic dysfunction predominates - ACE inhibitors, ARBs, ARNI, beta-blockers, aldosterone antagonists, SGLT2 inhibitors all reduce mortality - Most robust evidence base for pharmacotherapy 2. **HFmrEF (41–49%):** - Intermediate zone with emerging evidence - SGLT2 inhibitors and ARNI showing benefit in recent trials - Prognosis better than HFrEF but worse than HFpEF 3. **HFpEF (≥50%):** - Diastolic dysfunction; higher prevalence in women and elderly - Limited pharmacotherapy; SGLT2i emerging as first-line agent - Diuretics for symptom relief; no mortality-reducing agents firmly established **Clinical Pearl:** The reclassification of HFimpEF (improved EF) acknowledges that some patients with initial HFrEF recover EF >40% with optimal therapy; these patients have intermediate outcomes and should continue evidence-based therapies.