Feasibility of automated detection of sleep apnea using implantable pacemakers and defibrillators: a comparison with simultaneous polysomnography recording

Purpose Sleep-related breathing disorders (SRBD) have been associated with adverse cardiovascular events and prognosis. Some modern pacemakers (PMK) and implantable cardioverter defibrillators (ICD) are equipped with thoracic impedance monitoring systems which allow detecting fluctuations in tidal volume occurring in SRBD. This study aimed at assessing the accuracy of a novel transthoracic impedance-based PMK/ICD sensor for automatic detection of SRBD. Methods We prospectively enrolled 31 consecutive patients scheduled for implantation of a PMK or an ICD with sleep respiratory disturbances monitoring capability. The results of unattended home nocturnal recordings expressed as apnea/hypopnea index (AHI) were compared with the respiratory disturbance index (RDI) stored in the cardiac device memory at the time polygraphy was performed. Results Among the 31 enrolled patients (20 men, mean age 70 +/- 8 years), a comparison between the data from polygraphy and cardiac device was feasible in 29 patients. According to the results of home nocturnal recording, a severe SRBD was observed in 7/29 (24.1%) patients. On the basis of receiver-operating characteristic curve analysis of RDI values, the optimal RDI cutoff value to identify severe SRBD was 47 episodes/h (sensitivity 100%, specificity 100%). Bland-Altman agreement analysis of AHI-RDI revealed a bias between measurements of - 11 episodes/h, with limits of agreement - 38 to 15 episodes/h. Conclusions In the present study, the novel transthoracic impedance-based monitoring system ApneaScan (TM) appeared effective in screening PMK and ICD patients for SRBD.