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

Abstract Background Patients with atrial fibrillation (AF) often have sleep apnea (SA), but diagnosis of SA with polysomnography is costly. SA monitoring (SAM) is a pacemaker feature that measures respiratory disturbance index (RDI), the sum of abnormal respiratory events divided by sleep duration. Objective To evaluate the incidence and severity of SA and its association with AF in an unselected pacemaker population. Methods RESPIRE was a multicenter, international, observational, open-label study following adult subjects for 18 months after implant with a SAM-enabled dual-chamber pacemaker. Severe SA was defined as average RDI ≥20 from implant to follow-up visit. The first co-primary endpoint was the difference in significant AF (cumulative AF episodes lasting ≥24 hours over 2 consecutive days) between subjects with severe versus non-severe SA at 12 months in the full analysis set (n=553). The second co-primary endpoint 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% (172/553). A higher incidence of significant AF was reported in patients with severe SA than in patients with non-severe SA (25.0% vs 13.9%; difference 11.1% [95% CI, 3.7%-18.4%; p=0.002]). 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=NS). Conclusions SA screening over 12 months identified severe SA in almost one-third of unselected pacemaker patients. Severe SA was associated with a higher incidence of significant AF.