Is there evidence for treating central sleep apnea (CSA) with Continuous Positive Airway Pressure (CPAP)?

Treatment of Central Sleep Apnea with CPAP

CPAP is suggested as a first-line treatment option for adults with central sleep apnea (CSA), but its effectiveness varies by CSA etiology and patient characteristics. 1

Evidence for CPAP in Central Sleep Apnea

Effectiveness by CSA Type

• Primary CSA and Treatment-Emergent CSA: The American Academy of Sleep Medicine (AASM) suggests using CPAP over no CPAP for primary CSA and treatment-emergent CSA with a conditional recommendation based on low certainty evidence 1

• CSA due to Medication/Substance Use: CPAP is suggested as a treatment option with conditional recommendation 1

• CSA due to Medical Conditions: CPAP may be beneficial in treating CSA related to various medical conditions 1

• Complex Sleep Apnea Syndrome (CompSAS): While CPAP can be prescribed in 87.9% of CompSAS patients, these patients experience more interface problems compared to those with obstructive sleep apnea, particularly:

  • Air hunger/dyspnea (8.8% vs 0.8%)
  • Inadvertent mask removal (17.7% vs 2.6%) 2

Heart Failure Considerations

• CSA due to Heart Failure: CPAP has shown mixed results in heart failure patients with CSA:

  • Can reduce AHI, improve LVEF, and decrease norepinephrine levels in some patients 3
  • However, the SERVE-HF trial failed to demonstrate a reduction in transplant-free survival at 24 months despite improvements in AHI and LVEF 3
  • A post-hoc analysis showed that patients whose AHI reduced to <15 events/hour at 3 months had better transplant-free survival 3

• IMPORTANT CONTRAINDICATION: For patients with heart failure with reduced ejection fraction (HFrEF), the ACC/AHA/HFSA guidelines explicitly state that adaptive servo-ventilation causes harm (Class III: Harm recommendation) 3

Alternative Treatments for CSA

When CPAP is ineffective or contraindicated, alternative options include:

• Bilevel Positive Airway Pressure (BPAP) with backup rate: Suggested for primary CSA, CSA due to medication/substance use, treatment-emergent CSA, and CSA due to medical conditions 1

• Adaptive Servo-Ventilation (ASV): Most effective for CompSAS but contraindicated in HFrEF 4

  • Reduces AHI to a mean of 5 events per hour
  • Approximately 64% of patients achieve an AHI <10 events/hour
  • CONTRAINDICATED in patients with HFrEF due to increased cardiovascular mortality 4

• Low-flow oxygen: Suggested for CSA due to heart failure and high-altitude CSA 1

• Acetazolamide: May be considered for primary CSA, CSA due to heart failure, medication-induced CSA, and high-altitude CSA 1

• Transvenous phrenic nerve stimulation: May be considered for primary CSA and CSA due to heart failure, though it's invasive and costly 1

Treatment Algorithm

1. Confirm diagnosis with polysomnography and evaluate for underlying conditions, especially heart failure

2. Assess ejection fraction to rule out HFrEF (contraindication for ASV)

3. Initial treatment approach:

   • For most CSA types without HFrEF: Trial CPAP first
   • For CSA with HFrEF: Consider BPAP with backup rate or low-flow oxygen
   • For CompSAS: Consider ASV if no HFrEF is present

4. Monitor response within first few weeks:

   • If AHI normalizes and symptoms improve: Continue therapy
   • If central events persist: Consider alternative treatment options

Common Pitfalls

• Failing to identify heart failure patients before initiating therapy
• Using ASV in patients with HFrEF (increases mortality)
• Not addressing adherence issues with CPAP (interface problems are common in CSA)
• Focusing solely on AHI reduction rather than patient-reported outcomes

CPAP remains a reasonable first-line option for many CSA patients, but treatment must be tailored based on CSA etiology, presence of heart failure, and patient response to therapy.