What are the risk factors for treatment-emergent central sleep apnea after Inspire (implantable neurostimulator) implantation?

Risk Factors for Treatment-Emergent Central Sleep Apnea After Inspire Implantation

Patients with pre-existing cardiovascular conditions, particularly heart failure and atrial fibrillation, are at highest risk for developing treatment-emergent central sleep apnea (TECSA) after Inspire hypoglossal nerve stimulator implantation. 1

Primary Risk Factors

• Cardiovascular comorbidities:

  • Heart failure 1
  • Atrial fibrillation 1
  • Other cardiovascular diseases that are independently associated with central sleep apnea 1

• Neurological conditions:

  • History of stroke 1
  • Neurological damage affecting respiratory control centers 1

Mechanism and Presentation

TECSA occurs when primary obstructive sleep apnea improves with treatment, but central events emerge or persist. This phenomenon has been documented with Inspire therapy, particularly:

• During titration at higher stimulation voltages 2
• Central events may emerge when obstructive events are treated, essentially "unmasking" underlying central apnea tendencies 1

A case report demonstrated that central apneas developed during hypoglossal nerve stimulator titration specifically at higher voltages, suggesting a voltage-dependent relationship 2.

Clinical Course

The natural history of TECSA after Inspire implantation appears to be favorable in many cases:

• Central events often resolve spontaneously with ongoing therapy at stable voltages 1, 2
• In some patients, central apneas may recur when attempting to increase voltage settings 2

Screening and Management

The American Academy of Sleep Medicine recommends:

1. Careful screening for pre-existing central sleep apnea before Inspire implantation 1
2. Thorough evaluation for cardiovascular comorbidities that might predispose to central events 1
3. If central apneas persist despite voltage adjustments, consideration of alternative therapies such as adaptive servo-ventilation 1, 3

Important Considerations

• The prevalence of TECSA specifically after Inspire implantation is not well established 1
• Ventilatory control instability, low arousal threshold, activation of lung stretch receptors, and prolonged circulation time are potential mechanisms leading to TECSA in general 3
• While most research on TECSA has focused on CPAP therapy, the phenomenon has been increasingly recognized with other OSA treatment modalities including hypoglossal nerve stimulation 3, 2

When managing patients with Inspire therapy who develop central events, voltage adjustment should be the first intervention, as central events may resolve at stable, appropriate voltage settings 2.