Night-To-Night Variability in Sleep Apnea Is Associated With Persistence and Burden of Device-Detected Atrial Fibrillation.

Using pacemaker-derived thoracic impedance monitoring, sleep apnea severity and its night-to-night variability can be continuously tracked in patients with implanted cardiac devices. In the prospective ACaSA study, 171 pacemaker patients without permanent atrial fibrillation at baseline were followed for a median of 539 days. During an initial 28-night run-in period free of atrial fibrillation, baseline night-to-night variability of the respiratory disturbance index (RDI) was quantified as the coefficient of variation. Patients were subsequently monitored for the onset of persistent device-detected atrial fibrillation (DDAF, ≥ 7 days) and cumulative DDAF burden. Median RDI variability was 38.7% (IQR 29.9%-47.6%), and 35 patients (20.5%) had high variability (≥ 50%). Over follow-up, 17 patients (9.9%) developed persistent DDAF. Each 10% increase in RDI variability was associated with a significantly higher risk of persistent DDAF (adjusted HR 1.89, 95% CI 1.26-2.84; p = 0.002). Patients with high variability also carried a greater cumulative DDAF burden compared to those with low variability (9.6% vs. 1.9%, p = 0.016). These results suggest that the dynamic instability of sleep apnea, reflected by night-to-night variability, is associated with DDAF persistence and burden. Continuous long-term monitoring through pacemaker systems offers a novel approach for risk stratification and may open opportunities for more personalised management strategies.