0578 Integrating Hypoxic Burden into Multi-Diagnostic Home Sleep Apnea Testing

Abstract Introduction Sleep apnea associated hypoxemia contributes to cardiovascular morbidity and arrhythmogenesis in sleep disordered breathing (SDB). However, traditional home sleep apnea tests (HSAT) provide limited physiologic characterization. Hypoxic burden (HB)—the cumulative area under event-related desaturations—has emerged as a promising predictor of cardiovascular outcomes compared with AHI alone. Despite this, clinical familiarity, consensus thresholds, and payer recognition remain limited, due in part to lack of widespread availability on HSAT platforms. Multi-diagnostic systems that quantify HB alongside AHI and ECG-based arrhythmias may support broader adoption. We evaluated HB in adults undergoing SDB assessment using a multi-diagnostic chest-worn HSAT (SANSA, Huxley Medical, Inc.). Methods Adults referred for suspected SDB underwent single-night monitoring with a chest-worn HSAT capturing nine physiologic channels, including oximetry, respiration, and ECG. Automated algorithms calculated AHI-3% and HB for analysis. Cardiovascular comorbidity was defined as history of atrial fibrillation, arrhythmia, heart failure, coronary artery disease, or myocardial infarction. Results Data from 325 adults (mean age 55.4±15.6 years, 47% male, BMI 33.7±8.6 kg/m2) were analyzed. Mean HB was 49.8±80.2%·min/hr. HB increased stepwise across OSA severity categories, from 4.3±3.0%·min/hr in normal to 16.9±8.7%·min/hr in mild, 36.7±15.6%·min/hr in moderate, and 117.7±117.8%·min/hr in severe SDB. HB was correlated with AHI (R=0.76, P< 0.001). Elevated HB (≥60%·min/hr) occurred in 23% (75/325), exclusively among those with moderate (n=5) or severe (n=70) SDB, with none in normal or mild categories. Elevated HB in moderate-to-severe SDB was associated with greater cardiac comorbidity compared to lower HB (OR: 2.4 [95% CI: 1.1, 5.1], P=0.047). Higher BMI (P< 0.01) and age (P=0.03) were associated with increased HB, though not after adjusting for AHI (P=0.96 and 0.54, respectively). No significant effects on HB were observed by sex or race. Conclusion These results demonstrate that HB can be measured from a multi-diagnostic chest-worn HSAT to add important physiologic context during SDB assessment. Given that most SDB testing uses HSAT, integrating HB alongside AHI and other cardiac comorbidity measurements, such as ECG-derived arrhythmias, could improve patient phenotyping to determine appropriate treatment. Further research is needed to determine clinically meaningful HB thresholds and investigate how AHI, HB, and cardiovascular comorbidity could jointly stratify risk in diverse real-world populations. Support (if any)