Validation and implementation of ambulatory obstructive sleep apnea polygraphy screening combined with wearable semi-continuous heart rhythm monitoring in patients with atrial fibrillation: a validation and a pilot study

Abstract

Background Obstructive sleep apnea (OSA) is a prevalent yet underdiagnosed risk factor in atrial fibrillation (AF) patients and may influence AF burden. Systematic OSA screening and long-term non-invasive heart rhythm monitoring to follow up on AF remain challenging in clinical practice. This study aimed to validate the NOX-T3s polygraphy (PG) device for OSA screening, and to evaluate the feasibility of a structured OSA screening pathway combined with semi-continuous heart rhythm monitoring for mapping AF recurrences and burden.Methods In the NOX-T3s validation study, NOX-T3s performance was evaluated in 30 AF patients undergoing PSG, with simultaneous and consecutive home NOX-T3s recordings. In the NOXFib-AF pilot study, the NOX-T3s was used for ambulatory OSA screening in another 30 AF patients, followed by 31 days of semi-continuous rhythm monitoring (every 9 min) via a smartwatch linked to the FibriCheck algorithm and twice-daily spot-checks via the FibriCheck smartphone application. Presence of AF was indicated as >= 1 AF measurement, with episodes defined as consecutive AF measurements terminated by a sinus rhythm measurement. Patients who screened OSA-positive were referred for PSG. Patient comfort with the devices was assessed via questionnaires.Results NOX-T3s demonstrated good diagnostic performance for detecting moderate-to-severe OSA (AUC 0.83 simultaneous; 0.80 home), with Apnea-Hypopnea Index (AHI) values comparable to PSG (simultaneous recording Delta 0.5 (IQR:-4.2-3.3); p = 0.942; separate-night recordings Delta 1.5 (IQR:-3.7-7.4); p = 0.306). An optimized AHI cut-off of 11.1 events/h improved NOX-T3s accuracy (0.85), with high sensitivity (92.9%) and specificity (75.0%). OSA screening was successful in the NOXFib-AF study in 97.1% of patients, identifying moderate-to-severe OSA in 79.3%. 91.3% underwent PSG, confirming OSA in 61.9%. Semi-continuous smartwatch-based rhythm monitoring was successful in 96.6%, 61.0% +/- 11.5 was high-quality data, and there was high compliance and motivation. AF was detected in 64.3%, and the smartwatch detected 6.7 times more AF episodes compared to spot-check alone. Comfort was high for both NOX-T3s (32 out of 40 (IQR: 29-35) and rhythm monitoring [34 out of 40 (IQR: 29-37)].Conclusions NOX-T3s with an AHI cut-off >= 11.1 events/h is a reliable home screening tool for moderate-to-severe OSA. NOX-T3s-based OSA screening combined with semi-continuous FibriCheck-based rhythm monitoring has proven feasible and acceptable in AF patients.