Long-term Screening for Sleep Apnoea in Paced Patients: Preliminary Assessment of a Novel Patient Management Flowchart by Using Automatic Pacemaker Indexes and Sleep Lab Polygraphy

• Published in: Heart, lung & circulation lung & circulation, 2014-10, Vol.23 (10), p.943-950
• Main Authors: Aimé, Ezio, MD, Rovida, Marina, MD, Contardi, Danilo, Ricci, Cristian, Gaeta, Maddalena, MD, Innocenti, Ester, MD, Cabral Tantchou-Tchoumi, Jacques, MD
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Apnoea and hypopnoea index; Artificial pacemaker; Cardiovascular; Female; Humans; Male; Middle Aged; Minute ventilation sensor; Monitoring, Physiologic; Pacemaker, Artificial; Pilot Projects; Polysomnography; Predictive Value of Tests; Prospective Studies; Retrospective Studies; Screening; Severity of Illness Index; Sleep Apnea, Obstructive - diagnosis; Sleep apnoea; Time Factors
• ISSN: 1443-9506; 1444-2892
• DOI: 10.1016/j.hlc.2014.04.001

Background The primary aim of this pilot study was to prospectively assess a flowchart to screen and diagnose paced patients (pts) affected by sleep apnoeas, by crosschecking indexes derived from pacemakers (minute ventilation sensor on-board) with Sleep-Lab Polygraphy (PG) outcomes. Secondarily, “smoothed” long-term pacemaker indexes (all the information between two consecutive follow-up visits) have been retrospectively compared vs. standard short-term pacemaker indexes (last 24 h) at each follow-up (FU) visit, to test their correlation and diagnostic concordance. Methods Data from long-term FU of 61 paced pts were collected. At each visit, the standard short-term apnoea+hypopnoea (PM_AHI) index was retrieved from the pacemaker memory. Patients showing PM_AHI ≥ 30 at least once during FU were proposed to undergo a PG for diagnostic confirmation. Smoothed pacemaker (PM_SAHI) indexes were calculated by averaging the overall number of apnoeas/hypopnoeas over the period between two FU visits, and retrospectively compared with standard PM_AHI. Results Data were available from 609 consecutive visits (overall 4.64±1.78 years FU). PM_AHI indexes were positive during FU in 40/61 pts (65.6%); 26/40 pts (65%) accepted to undergo a PG recording; Sleep-Lab confirmed positivity in 22/26 pts (84.6% positive predictive value for PM_AHI). A strong correlation (r=0.73) and a high level of concordance were found between smoothed and standard indexes (multivariate analysis, Cohen's-k and Z-score tests). Conclusions Pacemaker-derived indexes may help in screening paced pts potentially affected by sleep apnoeas. Long-term “smoothed” apnoea indexes could improve the accuracy of pacemaker screening capability, even though this hypothesis must be prospectively confirmed by larger studies.