Continuous monitoring of sleep-disordered breathing with pacemakers: Indexes for risk stratification of atrial fibrillation and risk of stroke

Abstract

Background: Sleep apnea (SA) is a risk factor for atrial fibrillation (AF). Advanced pacemakers are now able to calculate indexes of SA severity.

Hypothesis: We investigated the changes in pacemaker-measured indexes of SA, we assessed their predictive value for AF occurrence and the associated risk of stroke and death at long-term.

Methods: We enrolled 439 recipients of a pacemaker endowed with an algorithm for the calculation of a Respiratory Disturbance Index (RDI). The RDI variability was measured over the first 12 months after implantation, as well as its potential association with the occurrence of AF, defined as device-detected cumulative AF burden ≥6 hoursours in a day.

Results: The individual RDI mean was 30 ± 18 episodes/h, and the RDI maximum was 59 ± 21 episodes/h. RDI ≥30 episodes/h was detected in 351 (80%) patients during at least one night. The proportion of nights with RDI ≥30 episodes/h was 14% (2%-36%). AF ≥6 hours was detected in 129 (29%) patients during the first 12 months. The risk of AF was higher in patients with RDI maximum ≥63 episodes/h (HR:1.74; 95%CI: 1.22-2.48; P = .001) and with RDI mean ≥ 46 episodes/h (HR:1.63; 95%CI: 1.03-2.57; P = .014). The risk of all-cause death or stroke was higher in patients with AF burden ≥6 hours (HR:1.75; 95%CI: 1.06-2.86; P = .016). Moreover, among patients with no previous history of AF the risk was higher in those with RDI maximum ≥63 episodes/h (HR:1.96; 95%CI: 1.06-3.63; P = .031).

Conclusions: Pacemaker-detected SA showed a considerable variability during follow-up. We confirmed the association between RDI and higher risk of AF, and we observed an association between higher RDI maximum and all-cause death or stroke among patients with no previous history of AF.

Keywords: atrial fibrillation; pacemaker; sleep apnea; stroke.

Conflict of interest statement

Sergio Valsecchi is employee of Boston Scientific, Inc. Giuseppe Boriani reported speaker's fees of small amount from Boston, Biotronik and Medtronic. No other conflicts of interest exist.

© 2020 The Authors. Clinical Cardiology published by Wiley Periodicals LLC.

Figures

FIGURE 1

Time to reach the maximum RDI value during the first 12 months after implantation, that is, proportion of patients with RDI max value Panel A). RDI mean values calculated at different time points during follow‐up (from implantation to first week, 1 month, 3 months, 6 months, 12 months) (Panel B). RDI burden values calculated at different time points during follow‐up (from implantation to first week, 1 month, 3 months, 6 months, 12 months) (Panel C)

FIGURE 2

Kaplan–Meier estimates of time to AF (≥6 hours in a day), stratified by: RDI max value (Panel A ‐ log‐rank test, HR: 1.74; 95%CI: 1.22‐2.48; P = .001), RDI mean value (Panel B ‐ log‐rank test, HR: 1.63; 95%CI: 1.03‐2.57; P = .014), RDI burden value (Panel C ‐ log‐rank test, HR: 1.44; 95%CI: 1.01‐2.06; P = .057)

FIGURE 3

Kaplan–Meier estimates of time to all‐cause death or stroke among patients with no previous history of AF, stratified by: RDI max value (Panel A ‐ log‐rank test, HR: 1.96; 95%CI: 1.06‐3.64; P = .031), RDI mean value (Panel B ‐ log‐rank test, HR: 1.50; 95%CI: 0.71‐3.14; P = .237), RDI burden value (Panel C ‐ log‐rank test, HR: 1.24; 95%CI: 0.66‐2.34; P = .524)