How to manage RASi and MRA therapy in a patient with HFrEF, CKD, and hyperkalemia?

Management of RASi and MRA Therapy in a Patient with HFrEF, CKD, and Hyperkalemia

Continue sacubitril-valsartan and spironolactone at the current dosages, and address correctable factors contributing to hyperkalemia. 1

Assessment of Current Situation

This 76-year-old female presents with several factors contributing to her hyperkalemia (K+ 5.4 mmol/L):

• Correctable factors:

  • Recent NSAID use (ibuprofen)
  • Trimethoprim-sulfamethoxazole (TMP-SMX) therapy
  • Decreased oral intake with dehydration (dry mucous membranes)
  • Worsened renal function (creatinine 2.2 mg/dL from baseline 1.7 mg/dL)
  • Metabolic acidosis (bicarbonate 16 mmol/L)

• Chronic factors:

  • CKD (eGFR 34 mL/min/1.73 m²)
  • HFrEF requiring RASi (sacubitril-valsartan) and MRA (spironolactone) therapy

Management Algorithm

Step 1: Address Correctable Factors

1. Discontinue ibuprofen immediately - NSAIDs can worsen renal function and contribute to hyperkalemia
2. Consider alternative to TMP-SMX if clinically appropriate - TMP-SMX inhibits potassium secretion in the distal tubule
3. Correct volume depletion with appropriate IV fluids
4. Address metabolic acidosis which can cause potassium to shift out of cells

Step 2: Continue RASi and MRA Therapy

According to KDIGO 2024 guidelines:

• Practice Point 3.6.3: "Hyperkalemia associated with use of RASi can often be managed by measures to reduce the serum potassium levels rather than decreasing the dose or stopping RASi" 1
• Practice Point 3.6.5: Consider reducing or discontinuing RASi only in cases of "uncontrolled hyperkalemia despite medical treatment" 1

Step 3: Monitor and Follow-up

• Check serum potassium and renal function within 2-4 days 2
• Continue monitoring weekly until stable, then monthly for 3 months 2

Rationale for Continuing RASi and MRA

1. Mortality benefit: Discontinuation of MRA due to hyperkalemia is associated with increased mortality in HFrEF patients 3

2. Mild hyperkalemia: The patient's potassium level (5.4 mmol/L) is only mildly elevated and does not warrant immediate discontinuation of these life-saving medications 1

3. Correctable factors: Multiple reversible causes of hyperkalemia are present that can be addressed without discontinuing RASi/MRA therapy 2

4. KDIGO guidance: The 2024 KDIGO guidelines specifically recommend addressing correctable factors rather than discontinuing RASi therapy for hyperkalemia 1

Important Caveats and Pitfalls

• Monitor closely: If potassium rises above 6.0 mmol/L despite addressing correctable factors, consider dose reduction or temporary discontinuation of RASi/MRA 1, 2

• Avoid triple RAAS blockade: The patient is already on sacubitril-valsartan and spironolactone, which is appropriate, but adding another RAAS inhibitor would significantly increase hyperkalemia risk 1

• Consider potassium binders: If hyperkalemia persists despite addressing correctable factors, newer potassium binders (patiromer or sodium zirconium cyclosilicate) may allow continuation of RASi/MRA therapy 4, 5

• Sacubitril-valsartan warnings: Monitor for other potential adverse effects including hypotension and worsening renal function 6

By addressing the correctable factors while maintaining these guideline-directed medical therapies, you can optimize this patient's heart failure management while minimizing the risk of recurrent hyperkalemia.