What are the recommendations for managing hyperkalemia and impaired renal function in a patient with CHF (congestive heart failure) on furosemide, metoprolol, Entresto, statin, and aspirin?

Management of Hyperkalemia and Impaired Renal Function in CHF

Adding an SGLT2 inhibitor is recommended for this patient with mild hyperkalemia and worsening renal function while on guideline-directed medical therapy for heart failure with reduced ejection fraction. 1

Assessment of Current Status

This 66-year-old female presents with:

• Heart failure with reduced ejection fraction (EF 30-35%)
• Currently asymptomatic without recent weight changes
• Medications: furosemide 20mg daily, metoprolol 25mg, Entresto (sacubitril/valsartan), statin, aspirin
• Stable blood pressure (99/65) and heart rate (79)
• Laboratory abnormalities:
  • Potassium 5.3 mEq/L (mild hyperkalemia)
  • BUN 27 mg/dL (elevated)
  • Creatinine 1.08 mg/dL (increased from 0.88 mg/dL 2 months ago)
  • eGFR 57 mL/min/1.73m²

Management Approach

1. SGLT2 Inhibitor Addition

• Adding an SGLT2 inhibitor is the most appropriate next step based on the most recent evidence 1
• SGLT2 inhibitors reduce the risk of serious hyperkalemia (HR 0.84; 95% CI, 0.76–0.93) across subgroups of patients taking RAAS inhibitors and MRAs
• This approach simultaneously addresses both hyperkalemia and provides cardiovascular and renal protection

2. Medication Considerations

• Maintain current Entresto therapy: Sacubitril/valsartan is associated with lower rates of severe hyperkalemia compared to ACE inhibitors (HR 1.37; 95% CI, 1.06-1.76) 1
• Continue current furosemide dose: The patient is euvolemic, and increasing diuretic dose is not indicated unless there are signs of fluid overload 1
• Monitor renal function: Worsening renal function in the context of heart failure therapy may not reflect true tubular injury and should be interpreted cautiously 1

3. Monitoring Recommendations

• Check potassium and renal function within 1 week of adding the SGLT2 inhibitor 1
• Continue monitoring at 2 weeks, 1 month, 3 months, and then every 3 months if stable 1
• Potassium goal: maintain between 4.0-5.0 mEq/L for optimal outcomes 2, 3

4. Additional Considerations

• If hyperkalemia persists despite SGLT2 inhibitor addition, consider:
  • Potassium binder therapy (patiromer or sodium zirconium cyclosilicate) 1, 4
  • Dietary potassium restriction (<40 mg/kg/day) 4
  • Avoid NSAIDs and other medications that may worsen hyperkalemia 4, 5

Cautions and Pitfalls

1. Avoid discontinuing GDMT: Withdrawal of guideline-directed medical therapy is associated with poorer clinical outcomes 1

2. Don't overdiurese: Excessive diuresis can worsen renal function and paradoxically increase hyperkalemia risk 4

3. Interpret creatinine changes carefully: Mild increases in creatinine are common with RAAS inhibitors and may not indicate clinically significant renal dysfunction 1

4. Recognize high-risk features for recurrent hyperkalemia:

   • Severe initial hyperkalemia
   • Low eGFR
   • Diabetes
   • Spironolactone use 6

5. Monitor for SGLT2 inhibitor side effects:

   • Genital mycotic infections
   • Volume depletion
   • Diabetic ketoacidosis (if diabetic)

By adding an SGLT2 inhibitor while maintaining the current heart failure regimen, this approach optimizes both cardiovascular outcomes and addresses the mild hyperkalemia and worsening renal function in this patient with heart failure with reduced ejection fraction.