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Internal MedicineCardiologyHeart Failure with Reduced Ejection Fraction (HFrEF)

Heart Failure with Reduced Ejection Fraction (HFrEF)

Must-Not-Miss / Red Flags

  • Cardiogenic shock: cold extremities, altered mental status, oliguria, lactate >2 mmol/L
  • Acute pulmonary edema: severe dyspnea, bilateral crackles, pink frothy sputum
  • Systolic BP <90 mmHg: contraindicates initiation of certain GDMT
Patient Explanation
“Your heart muscle has become weaker and can’t pump blood as well as it should. We’ll give you medicines that have been proven to help your heart work better and keep you feeling well.”
Board Fact
“Quadruple therapy (ARNI/ACEi/ARB, beta‑blocker, MRA, SGLT2i) is the foundation of guideline‑directed medical therapy (GDMT) for HFrEF.”
ICD-10
I50.20

Definition & Core Concept

Heart failure with reduced ejection fraction (HFrEF) is a clinical syndrome characterized by impaired left ventricular systolic function (LVEF ≤40%), leading to inadequate cardiac output and/or elevated filling pressures, resulting in dyspnea, fatigue, and fluid retention.

Epidemiology & Risk Factors

  • Prevalence: 6.7 million adults in the US; increases with age
  • Leading cause of hospitalization in adults >65 years
  • 5‑year mortality ~50%, comparable to many cancers

Pathophysiology (Rule of 3)

  1. Initial myocardial injury (ischemia, hypertension, valvular disease, toxins) → myocyte loss and fibrosis
  2. Neurohormonal activation (RAAS, sympathetic nervous system) → vasoconstriction, sodium retention, adverse remodeling
  3. Progressive left ventricular dilation and systolic dysfunction → low cardiac output and congestion

Clinical Presentation

  • Dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea
  • Fatigue, reduced exercise tolerance
  • Elevated JVP, peripheral edema, hepatomegaly, S3 gallop

Diagnostic Workup

Echocardiogram: LVEF ≤40%, LV dilation. BNP/NT‑proBNP: elevated. Chest X‑ray: cardiomegaly, pulmonary congestion. Labs: BMP, LFTs, TSH, iron studies. ECG: may show prior MI, LBBB.

Management Protocol

  1. Diuretics: Furosemide for congestion
  2. ARNI/ACEi/ARB: Sacubitril‑Valsartan (ARNI) preferred; or Lisinopril/Losartan
  3. Beta‑blocker: Carvedilol, Metoprolol Succinate, or Bisoprolol
  4. MRA: Spironolactone or Eplerenone
  5. SGLT2i: Dapagliflozin or Empagliflozin
  6. Device therapy: ICD if LVEF ≤35% on optimal GDMT; CRT if LBBB and QRS ≥150 ms

Complications & Prognosis

  • Cardiogenic shock
  • Atrial and ventricular arrhythmias
  • Stroke (from LV thrombus)
  • Progressive renal dysfunction (cardiorenal syndrome)

ICU Criteria

ICU/CCU admission if: cardiogenic shock requiring inotropes/vasopressors, acute pulmonary edema needing NIPPV/intubation.

Clinical Vignette

A 65‑year‑old man with history of HTN and prior MI presents with progressive dyspnea on exertion and bilateral leg edema. Echo shows LVEF 30% with global hypokinesis. NT‑proBNP is 4,200 pg/mL.

Pearls & Pitfalls

  • GDMT should be initiated at low doses and uptitrated every 2‑4 weeks as tolerated – even small doses reduce mortality.
  • ARNI is superior to ACEi in reducing mortality and HF hospitalizations.

Discharge & Follow-Up

Weekly weight monitoring, sodium restriction (<2g/day), medication titration visits every 2 weeks, cardiac rehabilitation referral. Repeat echo in 3‑6 months to assess remodeling.

Literature & Guidelines

ACC/AHA 2024 Guideline for the Management of Heart Failure. PMID: 38562201.

Personal Clinical Notes