0511 Predictive Value of Peripheral Arterial Tonometry (PAT)-Derived Central Indices for Advanced PAP Modality Selection in Severe Obstructive Sleep Apnea

Abstract Introduction Home sleep apnea testing using peripheral arterial tonometry (PAT) can estimate central sleep apnea (CSA) and Cheyne–Stokes respiration (CSR). However, the clinical effectiveness of these indices in anticipating positive airway pressure (PAP) modality requirements is not well established. This study evaluated whether PAT-derived central indices in patients diagnosed with severe obstructive sleep apnea (OSA) were associated with escalation to advanced PAP modalities during subsequent titration polysomnography (PSG). Methods We conducted a retrospective review of adults with severe OSA, central apnea index (pAHIc) ≥5 events/hr, and CSR reported on diagnostic PAT testing (WatchPAT ONE™ was used) who subsequently underwent PSG with PAP titration within 12 months. PAT indices reviewed were pAHI 3%, pAHIc, and CSR percentage. Titration PSG results included residual CSA (AHIc ≥5 events/hr), presence of CSR, and prescribed PAP modality. These were categorized as continuous PAP (CPAP), auto-PAP versus advanced PAP modalities, such as bilevel PAP, including adaptive servo-ventilation (ASV). Associations between PAT-derived central apnea burden and titration outcomes were examined, including subgroup trends in patients with congestive heart failure (CHF). Results Twelve patients met inclusion criteria (mean age 61.2±12.8 years; BMI 36.3±11.9 kg/m2). Five patients (42%) had CHF. The mean pAHI 3% on the PAT studies was 56.2±13.9 events/hr, the mean pAHIc was 16.8±9.1 events/hr, with a mean CSR occurring in 22.8±15.8% of estimated sleep. Patients prescribed advanced PAP modalities (50%) demonstrated higher pAHIc burden compared with those treated with CPAP (median pAHIc 18.4 vs 11.9 events/hr; CSR 24.6% vs 17.3%). Furthermore, patients with CHF were more likely to need an advanced PAP (80% vs 29% without CHF). CSR was observed during titration in only 2 patients, both of whom had heart failure with preserved ejection fraction and required ASV. These two individuals demonstrated elevated WatchPAT-estimated central burden, with a mean pAHIc 26.1 events/hr and a high mean CSR 45.8%. Conclusion Increased PAT-derived CSA and CSR indices, particularly among individuals with CHF, were associated with escalation to advanced PAP modalities in patients with severe OSA. These findings suggest that PAT-derived central burden may help risk-stratify patients who are more likely to require advanced PAP modalities and help guide appropriate management. Support (if any)