Guideline-directed medical therapy

GDMT Basics - Why, Who, & How

• Why: Counteract maladaptive neurohormonal systems (RAAS, SNS) to reduce mortality and hospitalizations in HFrEF.
• Who: All patients with symptomatic Heart Failure with reduced Ejection Fraction (HFrEF) (LVEF ≤ 40%).
• How: Initiate the "four pillars" of GDMT, often simultaneously at low doses, and titrate to target.

⭐ High-Yield: SGLT2 inhibitors (e.g., dapagliflozin) reduce mortality and hospitalization in HFrEF patients, even those without diabetes.

HFrEF Pillars - The Fantastic Four

Cornerstone therapy for HFrEF (LVEF ≤ 40%) aimed at blocking key neurohormonal pathways to reduce mortality and hospitalizations. All four agents should be initiated as tolerated.

• ARNI / ACEi / ARB: Sacubitril/valsartan is preferred. Blocks RAAS & enhances natriuretic peptides.
  • Benefit: ↓ Mortality, ↓ Hospitalizations.
• Beta-Blockers: Use evidence-based options (Carvedilol, Metoprolol succinate, Bisoprolol).
  • Benefit: ↓ Mortality, ↓ Arrhythmias, reverses remodeling.
• Mineralocorticoid Receptor Antagonists (MRA): Spironolactone or Eplerenone.
  • Benefit: ↓ Mortality, ↓ Fibrosis.
  • ⚠️ Monitor for: Hyperkalemia, gynecomastia (spironolactone).
• SGLT2 Inhibitors: "-gliflozins" (e.g., Dapagliflozin, Empagliflozin).
  • Benefit: ↓ CV mortality & hospitalizations.

⭐ SGLT2 inhibitors provide significant mortality and morbidity benefits in HFrEF patients, irrespective of whether they have type 2 diabetes.

Treatment Algorithm - The GDMT Gauntlet

• HFrEF (LVEF ≤ 40%): Initiate all 4 pillars concurrently at low doses; titrate every 2 weeks to maximally tolerated doses.

⭐ SGLT2 inhibitors (e.g., dapagliflozin) are a cornerstone, reducing mortality and hospitalizations in HFrEF patients, even without diabetes.

• Add-on therapy: For persistent symptoms after maximizing pillars, consider ivabradine, hydralazine/isosorbide dinitrate, or digoxin.

Adjuncts & HFpEF - The Supporting Cast

• Ivabradine: For symptomatic HFrEF patients in normal sinus rhythm with a heart rate ≥ 70 bpm, already on maximum tolerated beta-blocker doses.
• Hydralazine/Isosorbide Dinitrate (H-ISDN): Recommended for African American patients with NYHA class III-IV HFrEF on optimal therapy to improve survival.
• Digoxin: Can be used to decrease hospitalizations in HFrEF; no mortality benefit. Narrow therapeutic index.
• HFpEF Management:
  • Focus on controlling comorbidities (e.g., hypertension, atrial fibrillation).
  • Use diuretics for congestion relief.
  • SGLT2 inhibitors are now recommended to reduce hospitalizations.

⭐ In HFpEF, mineralocorticoid receptor antagonists (MRAs) may be considered to decrease hospitalizations, especially in patients at the lower end of the LVEF spectrum.

High-Yield Points - ⚡ Biggest Takeaways

• Guideline-Directed Medical Therapy (GDMT) for HFrEF rests on four key pillars, all providing a significant mortality benefit.
• These are: ARNI (sacubitril-valsartan) preferred over ACEi/ARB, an evidence-based beta-blocker, an MRA (spironolactone), and an SGLT2 inhibitor.
• Initiate all four agents at low doses and titrate upwards as tolerated.
• Loop diuretics are essential for symptom relief (congestion) but do not improve mortality.
• Add hydralazine/isosorbide dinitrate for African American patients with persistent symptoms.