What is the recommended guideline‑directed medical therapy for a patient with a moderately reduced left ventricular ejection fraction (approximately 35‑45%)?

Guideline-Directed Medical Therapy for Moderately Reduced Ejection Fraction (35-45%)

Patients with moderately reduced ejection fraction (35-45%) should receive the same quadruple therapy regimen as those with HFrEF (EF ≤40%), consisting of ARNI (or ACE-I/ARB), evidence-based beta-blocker, mineralocorticoid receptor antagonist, and SGLT2 inhibitor, initiated simultaneously at low doses and rapidly uptitrated to target doses. 1

Primary Therapeutic Approach

The evidence strongly supports treating patients with EF 35-45% identically to those with HFrEF:

• Start all four foundational medication classes simultaneously at low initial doses rather than sequential initiation, as this approach reduces 2-year mortality by approximately 73% compared to no disease-modifying therapy. 1

• SGLT2 inhibitors (dapagliflozin or empagliflozin) should be initiated immediately as they demonstrate consistent benefit across the entire LVEF spectrum of 35-49% without significant interaction by ejection fraction subgroups, and they provide rapid clinical benefit within weeks. 2, 1

The Four Pillars of Therapy

1. Renin-Angiotensin System Inhibition

• Sacubitril/valsartan (ARNI) is the preferred agent, providing ≥20% relative mortality reduction compared to 5-16% with ACE-I/ARB alone. 1

• If ARNI is not tolerated or available, initiate an ACE inhibitor (e.g., enalapril starting at low dose, target 10-20 mg twice daily) or ARB (e.g., losartan starting at 25-50 mg daily, target 50-150 mg daily). 1

• When switching from ACE-I to ARNI, observe a strict 36-hour washout period to avoid angioedema. 1

2. Evidence-Based Beta-Blockers

Only three beta-blockers have proven mortality benefit and should be used: 1

• Carvedilol: start 3.125 mg twice daily; target 25-50 mg twice daily

• Metoprolol succinate: start 12.5-25 mg daily; target 200 mg daily

• Bisoprolol: start 1.25 mg daily; target 10 mg daily

• Beta-blockers provide ≥20% mortality reduction and lower sudden cardiac death risk across the EF spectrum of 40-49%. 2

3. Mineralocorticoid Receptor Antagonists

• Spironolactone or eplerenone each provide ≥20% mortality reduction and reduce the composite endpoint of cardiovascular death, HF hospitalization, or resuscitated sudden death in patients with LVEF 44-49%. 2, 1

• Start spironolactone at 12.5-25 mg daily or eplerenone at 25 mg daily, uptitrating to target doses (spironolactone 25-50 mg daily, eplerenone 50 mg daily). 1

• Eplerenone avoids the 5.7% higher rate of male gynecomastia seen with spironolactone. 1

4. SGLT2 Inhibitors

• Dapagliflozin or empagliflozin require no dose titration and can be started at full dose immediately after hemodynamic stabilization. 1

• These agents have no significant effects on blood pressure, heart rate, or potassium, making them ideal for early initiation even in patients with borderline low blood pressure. 1

• Clinical benefits occur within weeks of initiation, independent of background therapy. 1

Practical Implementation Strategy

Simultaneous Initiation Protocol

• Start all four medication classes at the same time after hemodynamic stabilization (≥24 hours of stability with adequate organ perfusion). 1

• Uptitrate every 1-2 weeks until target doses are achieved, checking blood pressure, renal function, and electrolytes 1-2 weeks after each dose increment. 1

• This addresses the massive treatment gap where currently <25% of eligible patients receive all four agents concurrently and only 1% achieve target doses of all medications. 1, 3

Monitoring Parameters

• Schedule early follow-up within 7-14 days after any medication change to evaluate volume status, blood pressure, renal function (creatinine, eGFR), and electrolytes (potassium). 1

• More frequent monitoring is required in elderly patients (≥65 years) and those with chronic kidney disease during uptitration. 1

• Modest creatinine increases up to 30% above baseline are acceptable and should not prompt discontinuation of ARNI/ACE-I/ARB. 1

Critical Pitfalls to Avoid

• Never discontinue GDMT if EF improves above 40%, as medication cessation may lead to clinical deterioration; patients with previous HFrEF whose EF improves should continue their full regimen. 1

• Do not withhold GDMT for asymptomatic hypotension when systolic BP is 80-100 mmHg and organ perfusion is adequate; patients can safely tolerate this range. 1

• Avoid accepting sub-target doses without aggressive uptitration attempts, as achieving target dosing provides the greatest mortality benefit. 1

• Do not delay beta-blocker initiation unnecessarily; start after volume optimization and discontinuation of IV diuretics, vasodilators, and inotropes, using low initial doses in hemodynamically stable patients. 1

Special Considerations for Low Blood Pressure

If systolic BP is around 90 mmHg at presentation:

• Prioritize SGLT2 inhibitor and MRA first, as these have minimal BP impact (SGLT2i lowers SBP by only 1.5 mmHg in patients with baseline SBP 95-110 mmHg). 1

• Add beta-blocker only if resting heart rate exceeds 60 bpm; if HR ≤60 bpm, defer beta-blocker until after ARNI/ACE-I/ARB has been started. 1

• Discontinue non-essential medications that may exacerbate hypotension (e.g., alpha-blockers for BPH, unnecessary antihypertensives). 1

Adjunctive Therapies

• Ivabradine (5 mg twice daily, target 7.5 mg twice daily) may be added only when a patient in sinus rhythm with NYHA class II-III symptoms has resting heart rate >70 bpm despite maximally tolerated beta-blocker therapy. 1

• Loop diuretics (furosemide, torsemide, or bumetanide) are essential for relieving congestion but do not confer mortality benefit; use only when fluid overload is present. 1

• For self-identified Black patients with NYHA class III-IV symptoms, add hydralazine (25 mg three times daily) combined with isosorbide dinitrate (20 mg three times daily) to quadruple therapy. 1

Evidence Strength Considerations

While the Class 2b recommendations for beta-blockers, ARNI/ACE-I/ARB, and MRAs in the 40-49% EF range are based on post-hoc and subset analyses rather than prospective RCTs specifically for this population, the consistent benefit across the EF spectrum and the established safety profile support treating patients with EF 35-45% identically to those with HFrEF. 2 The alternative—withholding proven life-saving therapy based on an arbitrary EF cutoff—carries unacceptable risk given the 73% mortality reduction achievable with quadruple therapy. 1