Effect of Continuous Positive Airway Pressure on Left Atrial Volume Index in Patients With Stroke and Obstructive Sleep Apnea: A Randomized Trial.

BACKGROUND: Obstructive sleep apnea is associated with left atrial enlargement, a predictor of stroke. We hypothesized that continuous positive airway pressure (CPAP) would reduce the left atrial volume index (LAVI) and modify its longitudinal trajectory in patients with stroke and obstructive sleep apnea. METHODS: Patients with stroke and obstructive sleep apnea were randomized to standard care plus CPAP or standard care alone. Coprimary outcomes were absolute 12-month change and longitudinal trajectories of LAVI and N-terminal pro-B-type natriuretic peptide (NT-proBNP), assessed at baseline and 3, 6, and 12 months. Functional outcomes were assessed at 3, 6, and 12 months. RESULTS: Seventy-one participants were randomized (35 CPAP, 36 control). LAVI did not change significantly from baseline to 12 months in either group, and the between-group difference in 12-month LAVI change (control-CPAP) was nonsignificant (mean difference, 0.5 mL/m2 [95% CI, -3.2 to 4.1 mL/m2]; P=0.804). A linear mixed-effects model for LAVI revealed a significant group×time interaction (P=0.005). NT-proBNP declined in the CPAP group (P=0.029) without between-group differences. Among 63 participants who completed follow-up, a significant quadratic interaction was observed, with a downward LAVI trajectory in the CPAP group and an upward trajectory in controls after 6 months (P=0.020). A modified Rankin Scale of 0 at 12 months was more frequent with CPAP (46.9% versus 22.6%; P=0.043). CONCLUSIONS: In participants with stroke and obstructive sleep apnea, CPAP did not significantly reduce 12-month LAVI compared with control; however, LAVI trajectories diverged over time. Among those who completed follow-up, complete neurologic recovery was more frequent with CPAP. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT04458779.