Abstract Body: Background and Purpose
Sleep disordered breathing (SDB), particularly obstructive sleep apnea (OSA), is an under-recognized risk factor for cardiovascular and cerebrovascular events, especially stroke. Although positive airway pressure (PAP) therapy is the established intervention for SDB, clear guidelines on the optimal timing for initiating PAP therapy after an acute ischemic stroke are lacking. This study aims to evaluate the adherence and long-term efficacy of early PAP therapy initiation in patients following acute cerebrovascular events.

Methods
This prospective observational study involved patients with acute ischemic stroke within 5 days of symptom onset and a STOP-Bang score of 3 or higher, indicating a moderate to high risk for OSA. After informed consent, participants underwent type 1 polysomnography (PSG) to diagnose SDB. Patients with an Apnea-Hypopnea Index (AHI) of 5 or higher initiated PAP therapy within 7 days of stroke onset during hospitalization. Adherence to PAP therapy was defined as using the device for at least 4 hours per night on 70% or more of nights. This interim analysis examines outcomes at 3 and 12 months post-stroke.

Results
Between December 2021 and October 2023, 191 patients were enrolled, with 169 diagnosed with OSA based on PSG. Among them, 95 initiated PAP therapy during hospitalization. At the 3-month follow-up, 45 patients (47.4%) demonstrated good adherence, with 36 patients (37.9%) maintaining this at 12 months. Those with good adherence exhibited better glycemic control (115.7 mg/dL vs. 117.6 mg/dL) and lower systolic blood pressure (128.1 mmHg vs. 130.8 mmHg) compared to those with lower adherence or no PAP use.

Conclusions
Interim findings suggest that early initiation of PAP therapy after acute ischemic stroke is feasible and effective, with tolerable adherence rates observed at 3 and 12 months. Patients who adhered to PAP therapy showed improvements in managing key vascular risk factors, suggesting potential long-term benefits of early intervention. These results indicate that early PAP therapy during the acute phase of ischemic stroke could be a beneficial approach for managing post-stroke patients with SDB.