Incidence of sleep apnea and association with atrial fibrillation in an unselected pacemaker population: Results of the observational RESPIRE study

Background Patients with atrial fibrillation (AF) often have sleep apnea (SA), but diagnosis of SA with polysomnography is costly. SA monitoring is a pacemaker feature that measures respiratory disturbance index, the sum of abnormal respiratory events divided by sleep duration. Objective The purpose of this study was to evaluate the incidence and severity of SA and its association with AF in an unselected population fitted with pacemakers. Methods RESPIRE (REgistry of Sleep APnea monItoring and Atrial Fibrillation in pacemakeR patients) was a multicenter, international, observational, open-label study following adult subjects for 18 months after implantation with an SA monitoring–enabled dual-chamber pacemaker. Severe SA was defined as average respiratory disturbance index ≥20 from implantation to follow-up visit. The first co-primary end point was the difference in significant AF (cumulative AF episodes lasting ≥24 hours over 2 consecutive days) between subjects with severe and those nonsevere SA at 12 months in the full analysis set (N = 553). The second co-primary end point was the rate of major serious adverse events at 18 months in the modified intention-to-treat set (N = 1024). Results Severe SA was detected in 31.1% (172 of 553). A higher incidence of significant AF was reported in patients with severe SA than in patients with nonsevere SA (25.0% vs 13.9%; difference 11.1%; 95% confidence interval 3.7%–18.4%; P = .002). Significant AF increased with time in both groups, but at a faster rate in the severe SA group. No intergroup difference in the overall rate of major serious adverse events was observed (P = .065). Conclusion SA screening over 12 months identified severe SA in almost one-third of unselected patients fitted with pacemakers. Severe SA was associated with a higher incidence of significant AF.