Management of Heart Failure with Reduced Ejection Fraction (HFrEF)

1. General Principles and Staging

2. Pharmacological Management - The "Pillars"

Pillar 1: RAAS Blockade

• First-line therapy; reduce mortality ~20-25% (CONSENSUS, SOLVD trials)
• Start at low dose, titrate up as tolerated (e.g., enalapril 2.5 mg → 10-20 mg twice daily)
• Contraindications: bilateral renal artery stenosis, pregnancy, history of angioedema
• Side effects: cough (~10-15%), hyperkalemia, renal impairment

• Used when ACEi is not tolerated (e.g., cough)
• Candesartan and valsartan have mortality benefit (CHARM-Alternative, Val-HeFT)
• Never combine with ACEi (worsens renal function, hyperkalemia without added mortality benefit)

• The PARADIGM-HF trial demonstrated sacubitril/valsartan was superior to enalapril, reducing cardiovascular death or HF hospitalization by 20% (HR 0.80)
• Now preferred over ACEi/ARB in patients who can tolerate it (Class I recommendation)
• Key rule: Withhold ACEi for at least 36 hours before switching to sacubitril/valsartan to prevent angioedema
• Contraindicated with ACEi concomitantly (Class III)

Pillar 2: Beta-Blockers

• Proven mortality benefit from three agents only: bisoprolol, carvedilol, and metoprolol succinate (extended-release)
• Indicated for all stable HFrEF patients with LVEF <40%, symptomatic or asymptomatic (Class I)
• Mechanism: Counteract chronic sympathetic activation; promote reverse LV remodeling, improve LVEF over weeks-months
• Biphasic effect: Short-term may worsen function (negative inotropy); long-term improves survival
• Start low, uptitrate slowly - no sooner than every 2 weeks; optimize diuretics first
• Can be started before discharge even in hospitalized HF patients

Pillar 3: Mineralocorticoid Receptor Antagonists (MRAs)

• Spironolactone or eplerenone - reduce mortality ~30% in NYHA class III-IV (RALES) and post-MI HF (EPHESUS)
• Indicated when LVEF ≤35% and NYHA class II-IV, eGFR >30 mL/min, K+ <5.0 mEq/L
• Main risk: hyperkalemia - monitor K+ and renal function closely
• Eplerenone preferred in men to avoid gynecomastia (selective MRA)
• Finerenone (non-steroidal, third-generation MRA) - less hyperkalemia; studied in HF with CKD/T2DM

Pillar 4: SGLT2 Inhibitors

• Dapagliflozin (DAPA-HF) and empagliflozin (EMPEROR-Reduced) - both reduce CV death/HF hospitalization by ~25% regardless of diabetes status
• Mechanisms: osmotic diuresis, natriuresis, reduced preload/afterload, metabolic effects, cardioprotection
• Added benefit of improved 6-minute walk distance and quality of life
• Well tolerated; risk of genital mycotic infections, DKA (rare in HFrEF)
• Now Class I recommendation in all HFrEF patients (LVEF ≤40%)

3. Management of Fluid Retention (Diuretics)

• First-line for fluid overload; act at the thick ascending limb of Henle
• Torsemide has better oral bioavailability than furosemide (less variable absorption)
• Dose-adjust based on daily weight, urine output, symptoms

• Added to loop diuretics for diuretic resistance ("sequential nephron blockade")
• Metolazone particularly useful - acts even when GFR is low

• Mild effect; used adjunctively; do not use if already on MRA

• Switch to IV furosemide
• Add thiazide (metolazone)
• Consider continuous IV infusion
• Rule out NSAID use, low-sodium diet non-compliance, excessive fluid intake

4. Additional Pharmacological Agents

Hydralazine + Isosorbide Dinitrate (H-ISDN)

• Reduces mortality in Black patients with HFrEF (A-HeFT trial - 43% mortality reduction)
• Class I in self-identified Black patients already on ACEi/BB who remain symptomatic
• Class IIa alternative when ACEi/ARB/ARNi are contraindicated (e.g., renal failure, hyperkalemia)

Ivabradine (I-channel/HCN inhibitor)

• Reduces heart rate by blocking the funny current (If) in the SA node
• Indicated when: sinus rhythm, HR ≥70 bpm, LVEF ≤35%, on maximally tolerated beta-blocker
• SHIFT trial: reduced HF hospitalization; no significant mortality benefit alone
• Class IIa recommendation

Digoxin (Cardiac Glycoside)

• Reduces HF hospitalizations but no mortality benefit (DIG trial)
• Used for symptom control in patients who remain symptomatic despite GDMT
• Also useful for rate control in AF + HFrEF
• Narrow therapeutic index; target serum level 0.5-0.9 ng/mL; caution in elderly/renal impairment

Omega-3 Fatty Acids (n-3 PUFA)

• GISSI-HF trial: 1 g/day reduced all-cause mortality (HR 0.91) and combined mortality/CV admissions
• Class IIa adjunctive therapy in patients on optimal GDMT

5. Device Therapy

Implantable Cardioverter-Defibrillator (ICD)

• Indicated for primary prevention of sudden cardiac death (SCD) when:
  • LVEF ≤35%
  • NYHA class II-III
  • On optimal GDMT for ≥3 months
  • Life expectancy >1 year with good functional status
• For ischemic cardiomyopathy: ≥40 days post-MI; for non-ischemic: ≥3 months on GDMT

Cardiac Resynchronization Therapy (CRT)

• Indicated when:
  • LVEF ≤35%
  • LBBB with QRS ≥150 ms (strongest evidence; Class I)
  • NYHA class II-IV on optimal GDMT
• Improves LV synchrony, reduces reverse remodeling, improves symptoms and survival
• CRT-D (with defibrillator) preferred in most eligible patients

Wearable Cardioverter-Defibrillator

• Used as a bridge in patients at high SCD risk but not yet ICD candidates (e.g., newly diagnosed non-ischemic CM awaiting GDMT response)

6. Management of Special Situations

Atrial Fibrillation in HFrEF

• Rate control (beta-blocker or digoxin) preferred initially
• Catheter ablation may be considered - CASTLE-AF trial showed mortality and HF hospitalization reduction
• Anticoagulation (warfarin or DOAC) for AF in HFrEF (stroke risk is high)

Coronary Artery Disease

• Revascularization (PCI or CABG) if significant ischemia or viable myocardium present
• STICH trial: CABG + medical therapy reduced mortality vs. medical therapy alone in ischemic CM with LVEF ≤35%

Valvular Disease

• Aortic stenosis: TAVR or surgical AVR when severe AS + HFrEF (careful hemodynamic management)
• Mitral regurgitation: TEER (MitraClip) for selected patients with secondary MR + HFrEF who remain symptomatic (COAPT trial: 38% reduction in HF hospitalization)

7. Advanced/Refractory HFrEF (Stage D)

8. Non-Pharmacological Measures

• Sodium restriction: <2 g/day
• Fluid restriction: ~1.5-2 L/day (especially in severe HF or hyponatremia)
• Daily weight monitoring: Alert at >2 lb gain in 24h or >5 lb in 1 week
• Cardiac rehabilitation: Improves functional capacity and quality of life (HF-ACTION trial)
• Smoking cessation, alcohol limitation
• Influenza and pneumococcal vaccination
• Sleep apnea treatment (CPAP for OSA)

Summary: Stepwise Initiation of GDMT

All HFrEF (LVEF ≤40%):
  Step 1: Start ACEi or ARB (or ARNi if tolerated/preferred)
       + Beta-blocker (bisoprolol / carvedilol / metoprolol succinate)
       + MRA (spironolactone/eplerenone) if LVEF ≤35%
       + SGLT2i (dapagliflozin / empagliflozin)
  
  Step 2: Uptitrate all four agents to target/maximum tolerated doses
  
  Step 3: Reassess LVEF at 3-6 months
    → If LVEF ≤35% + LBBB QRS ≥150ms → Consider CRT-D
    → If LVEF ≤35% → Consider ICD (if not already CRT-D)
  
  Step 4: Persistent symptoms?
    → Add ivabradine (if HR ≥70, sinus rhythm)
    → Add hydralazine/ISDN (if intolerant of RAAS agents or Black patients)
    → Digoxin for symptom control / AF rate control
  
  Stage D → LVAD / Transplant evaluation

• Braunwald's Heart Disease, Chapter 50 (Management of HFrEF) - ACEi, ARB, ARNi, beta-blockers, MRA, SGLT2i, diuretics, device therapy
• Braunwald's Heart Disease - PARADIGM-HF, RALES, DAPA-HF, EMPEROR-Reduced trial data
• Recent PubMed evidence: Network meta-analysis (PMID 39578732) confirms the four-pillar combination as most effective pharmacological strategy; SGLT2i meta-analysis (PMID 38498097) confirms functional benefits across HFrEF