Do Not Switch ARNI to ARB/ACEI in HFrEF with Improved EF
In patients with heart failure with reduced ejection fraction (HFrEF) whose ejection fraction has improved to normal range, guideline-directed medical therapy including ARNI (sacubitril-valsartan) should be continued indefinitely to prevent relapse of heart failure and left ventricular dysfunction, even if patients become asymptomatic. 1, 2
The Evidence is Clear: Continue ARNI Therapy
The 2022 AHA/ACC/HFSA guidelines explicitly address this scenario with a Class I, Level B-R recommendation: patients with heart failure with improved ejection fraction (HFimpEF) after treatment must continue their guideline-directed medical therapy to prevent relapse 1, 2. This represents the highest strength of recommendation based on randomized controlled trial evidence.
Why Continuation is Critical
Stopping or downgrading therapy risks cardiac decompensation. When patients with HFrEF improve their LVEF to >40%, they are reclassified as having HFimpEF, but this does not mean they are cured 1, 2. The improvement in ejection fraction is a result of the therapy, not a reason to discontinue it.
The PROVE-HF study demonstrated that sacubitril-valsartan produces significant reverse cardiac remodeling, with median LVEF increasing from 28.2% to 37.8% after 12 months 3. This improvement reflects ongoing therapeutic benefit that would be lost if therapy were discontinued or downgraded.
The Superiority of ARNI Over ACEIs/ARBs
Sacubitril-valsartan is recommended as replacement therapy for ACEIs/ARBs in symptomatic HFrEF (Class I, Level A recommendation) 1, 4. The PARADIGM-HF trial showed sacubitril-valsartan reduced cardiovascular death or heart failure hospitalization by 20% compared to enalapril, with a 16% reduction in all-cause mortality 4, 5.
Switching from ARNI to an ACEI/ARB would reverse this benefit. The Canadian guidelines are particularly emphatic: ARNI should be used "in place of an ACEI or ARB" in patients with HFrEF who remain symptomatic despite appropriate GDMT 6.
Practical Management Algorithm
For Patients with HFimpEF on ARNI:
- Continue current ARNI dose - Do not reduce or switch to ACEI/ARB
- Maintain other GDMT components:
- Beta-blocker
- Mineralocorticoid receptor antagonist (MRA)
- SGLT2 inhibitor
- Monitor for relapse indicators:
- Symptoms (dyspnea, fatigue, edema)
- NT-proBNP levels
- Serial echocardiography every 6-12 months
- If LVEF declines again, intensify therapy rather than maintain status quo
Common Pitfall to Avoid
Do not interpret improved EF as permission to de-escalate therapy. This is therapeutic inertia in reverse. The 2021 CCS/CHFS guidelines emphasize that GDMT should be continued "to prevent relapse of HF and left ventricular dysfunction, even in patients who may become asymptomatic" 6.
The Four-Pillar Approach Remains Mandatory
Current guidelines establish a new standard requiring four medication classes for HFrEF 1, 6:
- ARNI (preferred over ACEI/ARB)
- Beta-blocker
- MRA
- SGLT2 inhibitor
This applies regardless of whether EF has improved. The 2022 guidelines explicitly state these medications "should be continued" in HFimpEF 1.
Safety Considerations
If tolerability issues arise with ARNI in the setting of improved EF:
- First, optimize diuretic dosing - reduce loop diuretics if volume status permits
- Separate timing of medications - if symptomatic hypotension occurs, space ARNI from other BP-lowering agents
- Reduce ARNI dose cautiously - only if absolutely necessary, and attempt re-titration when stable
- Never switch to ACEI/ARB - this represents a downgrade in therapy with proven inferior outcomes
The FDA Label Perspective
The FDA-approved indication for sacubitril-valsartan is "to reduce the risk of cardiovascular death and hospitalization for heart failure in adult patients with chronic heart failure and reduced ejection fraction" 7. Notably, the label acknowledges that "LVEF is a variable measure" and recommends using "clinical judgment in deciding whom to treat" 7. This supports continuing therapy even when EF improves, as the underlying disease process (chronic heart failure) persists.