How is lactic acidosis managed in patients with Heart Failure with reduced Ejection Fraction (HFrEF)?

Management of Lactic Acidosis in HFrEF

In patients with heart failure with reduced ejection fraction (HFrEF), lactic acidosis management should prioritize treating the underlying heart failure with guideline-directed medical therapy (GDMT) while simultaneously addressing the acidosis through careful hemodynamic optimization and targeted interventions to improve tissue perfusion.

Understanding Lactic Acidosis in HFrEF

• Lactic acidosis in HFrEF typically results from tissue hypoperfusion due to reduced cardiac output, leading to anaerobic metabolism and lactate accumulation 1
• High lactate levels in HFrEF patients are associated with significantly increased risk of cardiovascular death and heart failure hospitalization (5.35-fold higher risk over 6 months) 2
• Patients with elevated lactate levels often demonstrate worse echocardiographic parameters, including higher mitral E/A ratios and lower TAPSE values, indicating more severe cardiac dysfunction 2

Primary Management Approach

1. Optimize Hemodynamics and Cardiac Output

• Implement core GDMT for HFrEF to improve cardiac output and tissue perfusion, which addresses the root cause of lactic acidosis 3

  • SGLT2 inhibitors should be initiated early as they do not lower blood pressure significantly and can be used safely even in patients with lower baseline blood pressure 3
  • Beta-blockers, ACEIs/ARBs, or ARNIs should be initiated at low doses and carefully titrated based on blood pressure tolerance 3
  • Mineralocorticoid receptor antagonists (MRAs) can be initiated early as they typically don't significantly reduce blood pressure 3

• For patients with low blood pressure (SBP <80 mmHg or symptomatic):

  • Evaluate for reversible non-HF causes of hypotension 3
  • Consider temporary reduction or discontinuation of non-HF medications that may contribute to hypotension 3
  • Start with SGLT2 inhibitors and MRAs first, then carefully add other GDMT components 3

2. Address Acidosis

• Judicious use of sodium bicarbonate may be necessary for severe acidosis (pH <7.2) but should be used cautiously to avoid complications such as hypernatremia, volume overload, and paradoxical intracellular acidosis 1

• Consider dialysis modalities for severe, refractory lactic acidosis, particularly in patients with concurrent renal dysfunction:

  • Peritoneal dialysis with bicarbonate-based dialysate can deliver physiologic buffer without causing significant hemodynamic instability 1
  • Hemodialysis may be considered in more stable patients but carries greater risk of hemodynamic compromise in HFrEF patients 1

3. Advanced Interventions for Refractory Cases

• Evaluate for cardiac resynchronization therapy (CRT) in eligible patients with left ventricular dyssynchrony, as CRT can improve cardiac output and blood pressure by approximately 5% 3

• Consider transcatheter valve interventions if significant valvular disease is contributing to reduced cardiac output:

  • Transcatheter aortic valve replacement (TAVR) for aortic stenosis can increase systolic blood pressure by an average of 15 mmHg 3
  • Transcatheter edge-to-edge repair (TEER) for severe mitral regurgitation can improve forward flow and enhance tissue perfusion 3

Special Considerations

• Avoid medications that may worsen lactic acidosis:

  • Metformin should be discontinued in patients with significant lactic acidosis 1
  • Use vasopressors cautiously as they may worsen peripheral perfusion despite increasing blood pressure 1

• For patients with persistent symptoms despite initial management:

  • Consider referral to an advanced heart failure specialist for evaluation of mechanical circulatory support options if appropriate 3
  • Evaluate for other contributing factors such as occult infection, liver dysfunction, or malignancy 1

Monitoring and Follow-up

• Monitor lactate levels, arterial blood gases, and renal function to assess response to therapy 1, 2

• Track hemodynamic parameters including blood pressure, heart rate, and signs of tissue perfusion 3

• Assess for improvement in heart failure symptoms and adjust therapy accordingly 3

• Continue GDMT even after resolution of lactic acidosis to prevent recurrence and improve long-term outcomes 4, 5

By addressing both the underlying heart failure and the resulting metabolic derangement, this comprehensive approach aims to reduce mortality and improve quality of life in HFrEF patients with lactic acidosis.