Heart Failure Pharmacotherapy
Evidence-based pharmacotherapy for heart failure with reduced ejection fraction, covering the four pillars of guideline-directed medical therapy.
## Overview
Heart failure with reduced ejection fraction (HFrEF, EF <= 40%) is treated with four foundational drug classes collectively termed guideline-directed medical therapy (GDMT). Each class independently reduces mortality, and their benefits are additive.
## Pillar 1: ARNI or ACE Inhibitor
Sacubitril/valsartan (ARNI) combines neprilysin inhibition with AT1 receptor blockade. The PARADIGM-HF trial demonstrated a 20% reduction in cardiovascular death versus enalapril. Neprilysin inhibition increases natriuretic peptides, promoting natriuresis and vasodilation. ARNI is preferred over standalone ACE inhibitors when tolerated. A 36-hour washout from ACE inhibitors is mandatory before initiating ARNI to prevent angioedema.
## Pillar 2: Beta-Blockers
Carvedilol, bisoprolol, and metoprolol succinate ER are the three beta-blockers with mortality benefit in HFrEF. They counteract chronic sympathetic overactivation, reducing heart rate, myocardial oxygen demand, and arrhythmia risk. Initiation should occur when the patient is euvolemic, starting at low doses with gradual uptitration over weeks. Short-term worsening of symptoms is possible but does not indicate treatment failure.
## Pillar 3: Mineralocorticoid Receptor Antagonists
Spironolactone and eplerenone block aldosterone, reducing myocardial fibrosis, sodium retention, and potassium wasting. The RALES trial showed a 30% mortality reduction with spironolactone. Eplerenone is more selective and causes less gynecomastia. Serum potassium and renal function must be monitored, especially when combined with ACE inhibitors or ARBs.
## Pillar 4: SGLT2 Inhibitors
Dapagliflozin and empagliflozin reduce heart failure hospitalization and cardiovascular death regardless of diabetes status. DAPA-HF and EMPEROR-Reduced trials confirmed these benefits. Mechanisms include osmotic diuresis, reduced preload, improved myocardial energetics, and anti-inflammatory effects. Genital mycotic infections are the most common side effect.
## Additional Agents
Loop diuretics (furosemide, bumetanide) manage fluid overload but have no mortality benefit. Hydralazine plus isosorbide dinitrate is an alternative vasodilator regimen, particularly beneficial in Black patients (A-HeFT trial). Ivabradine reduces heart rate via funny channel blockade when beta-blocker uptitration is limited. Digoxin reduces hospitalizations but not mortality.
## Implementation
Current guidelines recommend initiating all four pillars simultaneously or in rapid sequence rather than sequential titration. This approach reduces time to full GDMT and improves outcomes. Dose optimization to target levels used in clinical trials is important.
## Key Takeaways
- Four drug pillars each independently reduce HFrEF mortality
- ARNI is preferred over ACE inhibitors when tolerated
- Only carvedilol, bisoprolol, and metoprolol succinate ER have HF evidence
- SGLT2 inhibitors benefit HFrEF patients regardless of diabetes status