Are patients who failed Continuous Positive Airway Pressure (CPAP) more or less likely to fail Inspire therapy?

Patients Who Failed CPAP Are More Likely to Fail Inspire Therapy

Patients who have previously failed CPAP therapy are more likely to fail hypoglossal nerve stimulation (Inspire therapy) compared to the general OSA population. This conclusion is based on the available evidence regarding treatment pathways for obstructive sleep apnea (OSA) patients who cannot tolerate first-line therapy.

Understanding CPAP Failure and Alternative Therapies

CPAP remains the gold standard first-line treatment for OSA according to multiple guidelines 1. When patients fail CPAP therapy (defined as usage <4 hours/night), several alternative options exist, including:

1. Bilevel positive airway pressure (BPAP)
2. Mandibular advancement devices (MADs)
3. Hypoglossal nerve stimulation (Inspire)
4. Surgical options

CPAP Failure Patterns and Implications

Patients fail CPAP for various reasons that may predict failure with other therapies:

• Intolerant pressures (23%)
• Uncontrolled symptoms (23%)
• Mask problems (21%)
• Adverse effects (13%)
• Claustrophobia (8%)
• Co-morbidities (8%) 2

These underlying issues—particularly claustrophobia, intolerance to therapy, and psychological factors—can predict difficulties with other device-based therapies like Inspire.

Evidence for Inspire Therapy After CPAP Failure

The European Respiratory Society guideline provides a conditional recommendation against hypoglossal nerve stimulation (HNS) as a first-line treatment for OSA patients in general, but notes it can be used in symptomatic OSA patients who have failed or not tolerated CPAP treatment 3.

However, several factors indicate higher failure rates with Inspire in CPAP-intolerant patients:

1. Adverse events: The MAUDE database review revealed significant complications with Inspire therapy, including infections (34.2%), neuropraxia (15.1%), and hematoma/seroma (11.6%). Importantly, 42.3% of adverse events required reoperation, with device explantation being the most common intervention (46.2%) 4.

2. Patient selection criteria: Inspire therapy has strict selection criteria based on the STAR trial, including specific AHI ranges (15-65/h) and BMI restrictions (<32 kg/m²) 3, 1. Many CPAP-intolerant patients may not meet these criteria.

3. Psychological factors: Patients who fail CPAP due to claustrophobia or device intolerance may have underlying psychological factors that could affect adherence to any device-based therapy 5.

Alternative Options for CPAP Failures

BPAP as Second-Line Therapy

BPAP has shown promise as a second-line therapy for CPAP failures. In a study of 52 patients who failed CPAP, BPAP achieved:

• Better adherence (7.0 vs 2.5 hours/night, p=0.028)
• Improved symptom control (ESS: 4.0 vs 10.0 points, p=0.039)
• Lower expiratory pressures compared to CPAP 2

Mandibular Advancement Devices

For mild to moderate OSA (AHI <30/h), mandibular advancement devices may be considered as an alternative therapy, though they are generally less effective than CPAP at reducing AHI 3, 1.

Treatment Algorithm for CPAP Failures

1. First attempt: Optimize CPAP therapy (mask fitting, pressure adjustments, humidification)
2. If continued failure: Try BPAP, especially for patients requiring high CPAP pressures (>15 cm H₂O) 2
3. For mild-moderate OSA: Consider custom-made dual-block mandibular advancement devices 3
4. For suitable candidates: Consider Inspire therapy if:
   • AHI 15-65/h
   • BMI <32 kg/m²
   • Patient understands higher risk of failure
   • No anatomical contraindications 3, 1
5. For severe anatomical issues: Consider multi-dimensional surgery targeting specific obstruction sites 6

Conclusion

While Inspire therapy can improve quality of life in selected patients with moderate/severe OSA who don't tolerate CPAP 7, the evidence suggests that patients who have failed CPAP are at higher risk of failing Inspire therapy due to overlapping intolerance factors, strict selection criteria, and significant complication rates requiring reoperation. BPAP appears to be a more effective second-line therapy for most CPAP failures, particularly in obese patients with high pressure requirements.