Sleep-disordered breathing (SDB) is an established risk factor for both stroke and atrial fibrillation (AF), yet optimal strategies for AF risk stratification after ischemic stroke remain uncertain.

An observational study published in the Journal of Sleep Research evaluated whether combining apnea-hypopnea index (AHI) with hypoxic burden improved AF risk stratification following ischemic stroke. A total of 911 patients with recent ischemic stroke underwent respiratory polygraphy within 3 days of the index event. Hypoxic burden was quantified as the cumulative area under the oxygen desaturation curve during respiratory events.

AF detection was performed using up to three 7-day electrocardiogram recordings over a 6-month follow-up period. Patients were stratified by AHI (≥15 vs <15 events/hour) and hypoxic burden (above vs below the median of 35% min·h⁻¹). Logistic regression adjusted for age, sex, and cardiovascular risk factors assessed associations with AF occurrence.

The cohort had a mean age of 66 ± 14 years, and 62% were men. AF was identified in 145 patients (16%) during follow-up. Patients with both elevated AHI (≥15 events/hour) and high hypoxic burden had higher odds of AF than those with lower values (adjusted odds ratio [OR], 1.97; 95% confidence interval [CI], 1.25–3.12). In contrast, neither elevated AHI alone nor high hypoxic burden alone was significantly associated with AF.

Combined assessment of AHI and hypoxic burden identified patients at higher risk of AF after ischemic stroke. Individual SDB metrics alone were not significantly associated with AF detection.