Can finerenone (Kerendia) be used instead of spironolactone in patients with heart failure with reduced ejection fraction who develop hyperkalemia?

Finerenone (Kerendia) Cannot Replace Spironolactone in HFrEF Patients with Hyperkalemia

Finerenone is NOT currently indicated for HFrEF and should not be used as a substitute for spironolactone in this population, even when hyperkalemia develops. The FDA-approved indications for finerenone are limited to chronic kidney disease associated with type 2 diabetes and heart failure with LVEF ≥40% (HFmrEF/HFpEF), explicitly excluding patients with HFrEF 1.

Current Evidence and Indications

FDA-Approved Uses for Finerenone

Finerenone is approved for:

• CKD with type 2 diabetes (FIDELIO-DKD and FIGARO-DKD trials) 2, 3, 2
• Heart failure with LVEF ≥40% (FINEARTS-HF trial) 1, 4

Notably, the FIGARO-DKD trial specifically excluded patients with heart failure with reduced ejection fraction 2. This exclusion criterion was intentional and reflects the lack of evidence supporting finerenone's use in HFrEF.

Established Role of Spironolactone in HFrEF

Spironolactone remains the evidence-based standard for HFrEF:

• RALES trial demonstrated 30% relative risk reduction in mortality in NYHA class III-IV HFrEF patients with LVEF ≤35% 5
• Spironolactone is a Class I, Level A recommendation for HFrEF with LVEF <30% and severe symptoms 6
• The 2022 AHA/ACC/HFSA guidelines support mineralocorticoid receptor antagonists (MRAs) as guideline-directed medical therapy (GDMT) for HFrEF 7

The Hyperkalemia Dilemma

Managing Hyperkalemia While Maintaining MRA Therapy

When hyperkalemia develops in HFrEF patients on spironolactone, the appropriate approach is NOT to switch to finerenone, but rather:

Step 1: Assess and Modify Risk Factors

• Review concomitant medications that increase potassium (NSAIDs, potassium supplements, salt substitutes high in K+) 5, 8
• Avoid triple therapy with ACE inhibitor + ARB + MRA 9
• Check for acute kidney injury or dehydration 6

Step 2: Dose Adjustment Protocol Based on Potassium Levels

• K+ 5.5-6.0 mmol/L: Halve the spironolactone dose (e.g., 25 mg to 12.5 mg or 25 mg on alternate days) and monitor closely 5, 8
• K+ >6.0 mmol/L: Stop spironolactone immediately, treat hyperkalemia, and monitor blood chemistry closely 5, 8
• K+ <5.5 mmol/L: Continue current dose with regular monitoring 5

Step 3: Consider Newer Potassium Binders

• Patiromer or sodium zirconium cyclosilicate can enable continuation of MRA therapy 9
• These agents allow maintenance of life-saving GDMT despite hyperkalemia risk

Step 4: Eplerenone as Alternative If spironolactone must be discontinued due to gynecomastia or persistent intolerance (not just hyperkalemia), eplerenone is the appropriate steroidal MRA alternative for HFrEF, not finerenone 5, 8.

Why Finerenone Is Not the Answer for HFrEF

Lack of Evidence in HFrEF Population

• No dedicated RCTs have evaluated finerenone specifically in HFrEF patients 10, 11
• The FINEARTS-HF trial enrolled only patients with LVEF ≥40%, with mean LVEF of 53% 4
• Small observational studies comparing finerenone to spironolactone in HFrEF show similar hyperkalemia rates (5.8% vs 6.2%) 10

Hyperkalemia Risk Persists with Finerenone

While finerenone may have marginally lower hyperkalemia rates compared to steroidal MRAs in some contexts 12, 13, 11, it still carries significant risk:

• 14% incidence of hyperkalemia in CKD trials (vs 6.9% with placebo) 3, 1
• 2.16-fold increased risk of K+ >5.5 mmol/L compared to placebo 14
• In FINEARTS-HF, 2.0% required hospitalization for worsening renal function 1

The FDA label explicitly warns: "Do not initiate Kerendia if serum potassium is >5.0 mEq/L" 1. This makes it unsuitable for patients who developed hyperkalemia on spironolactone.

Guideline Perspective on Finerenone

The 2025 KDOQI guidelines state that finerenone has a lower risk for hyperkalemia compared with steroidal MRAs, but this recommendation applies specifically to diabetic CKD patients, not HFrEF 12. The 2025 BMJ living guideline even suggests against using finerenone in moderate-risk patients with CKD due to limited benefit and hyperkalemia risk 15.

Clinical Algorithm for HFrEF Patients with Hyperkalemia on Spironolactone

HFrEF patient develops hyperkalemia on spironolactone
↓
Check K+ level and assess clinical context
↓
├─ K+ 5.5-6.0 mmol/L
│  ├─ Reduce spironolactone dose by 50%
│  ├─ Eliminate K+-sparing drugs/supplements
│  ├─ Consider potassium binder (patiromer/ZS-9)
│  └─ Recheck K+ in 1 week
│
├─ K+ >6.0 mmol/L
│  ├─ STOP spironolactone immediately
│  ├─ Treat hyperkalemia acutely
│  ├─ Investigate precipitants (AKI, NSAIDs, dehydration)
│  └─ After K+ normalizes:
│     ├─ Restart at lower dose (12.5 mg) with potassium binder
│     └─ If recurrent: Consider eplerenone (NOT finerenone)
│
└─ Persistent intolerance despite above measures
   ├─ If due to gynecomastia: Switch to eplerenone
   └─ If due to recurrent hyperkalemia:
      ├─ Optimize potassium binders
      ├─ Ensure adequate diuresis
      └─ Accept lower MRA dose rather than discontinuation

Critical Pitfalls to Avoid

1. Do not substitute finerenone for spironolactone in HFrEF - there is no evidence base and it remains off-label
2. Do not prematurely discontinue spironolactone for K+ 5.0-5.5 mmol/L - dose reduction and monitoring are appropriate 5, 9
3. Do not ignore the mortality benefit - spironolactone reduces death by 30% in severe HFrEF; hyperkalemia management should prioritize maintaining therapy 5
4. Do not use triple neurohormonal blockade (ACE-I + ARB + MRA) - this substantially increases hyperkalemia risk 8, 9

When Finerenone IS Appropriate

Finerenone should be considered in:

• HFmrEF/HFpEF patients (LVEF ≥40%) with persistent symptoms 1, 4
• Type 2 diabetes with CKD and albuminuria despite RAS inhibition 12, 3
• Patients who cannot tolerate SGLT2 inhibitors but need additional cardiorenal protection 12

In these populations, finerenone demonstrates cardiovascular and renal benefits with careful potassium monitoring (check K+ before initiation, at 1 month, and periodically thereafter) 1.

Bottom Line

For HFrEF patients who develop hyperkalemia on spironolactone, the solution is optimized hyperkalemia management—not switching to finerenone. Use dose reduction, potassium binders, elimination of contributing factors, and if necessary, eplerenone as an alternative steroidal MRA. Finerenone lacks evidence in HFrEF, carries its own hyperkalemia risk, and is not FDA-approved for this indication. The proven mortality benefit of spironolactone in HFrEF warrants aggressive efforts to maintain MRA therapy rather than abandoning this drug class 5, 6, 7.