The variability and burden of severe sleep apnea and the relationship with atrial fibrillation occurrence: analysis of pacemaker-detected sleep apnea

STUDY OBJECTIVES: This was a pilot study to evaluate the long-term variability and burden of respiratory disturbance index (RDI) detected by pacemaker and to investigate the relationship between RDI and atrial fibrillation (AF) event in patients with pacemakers. METHODS: This was a prospective study enrolling patients implanted with a pacemaker that could calculate the night-to-night RDI. The mean follow-up was 348 ± 34 days. The RDI variability was defined as the standard deviation of RDI (RDI-SD). RDI burden was referred to as the percentage of nights with RDI ≥ 26. The patient with RDI ≥ 26 in more than 75% nights was considered to have a high sleep apnea (SA) burden. An AF event was defined as a daily AF duration > 6 h. RESULTS: Among 30 patients, the mean RDI of the whole follow-up period was 24.5 ± 8.6. Nine (30%) patients were diagnosed with high SA burden. Patients with high SA burden had a higher BMI (26.7 ± 4.8 vs 23.2 ± 3.9, p = 0.036), a higher prevalence of hypertension (86% vs 39%, p = 0.031), and a larger left ventricular diastolic diameter (49.2 mm vs 46.7 mm, p = 0.036). The RDI-SD in patients with a higher burden was significantly greater than that in the patients with less burden (10.7 ± 4.9 vs 5.7 ± 1.4, p = 0.036). Linear regression showed that participants with a higher RDI tended to have a higher SD (R = 0.661; p < 0.001). The mean RDI (OR = 1.118, 95%CI 1.008–1.244, p = 0.044) was associated with AF occurrence. CONCLUSION: Using a metric such as burden of severe SA may be more appropriate to demonstrate a patient’s true disease burden.