Anouk Delaet

Myocardial infarction (MI) causes extensive cardiomyocyte loss and adverse remodeling, frequently progressing to heart failure. Although stem cell-based therapies are being investigated for cardiac repair, clinical outcomes remain modest. Cardiac atrial appendage stem cells (CASCs) harbor cardiomyogenic potential, making them promising candidates for cardiac regeneration. This proof-of-concept pilot study investigates the feasibility and preliminary therapeutic potential of delivering CASCs within an elastin-like recombinamer (ELR) hydrogel scaffold following MI. MI was induced in rats by permanent ligation of the left anterior descending coronary artery. Immediately after occlusion, CASCs (MI+C), ELR hydrogel (MI+H), or CASCs embedded in ELR hydrogel (MI+C+H) were injected intramyocardially into the peri-infarct region. MI and SHAM-operated animals served as controls. Four weeks post-MI, echocardiography showed a large, non-significant left ventricular ejection fraction improvement in MI+C+H versus MI, with a trend toward reduced end-diastolic volume. MI+C+H significantly improved anterior wall thickness versus MI+H, with favorable trends for MI+C. Wall motion score index showed a similar large, non-significant effect. Transcriptomics suggested the MI+C+H molecular profile reflected complementary contributions of both monotherapies rather than distinct synergistic mechanisms. These preliminary findings support ELR-mediated CASC delivery and suggest potential benefits for preserving cardiac function and limiting adverse remodeling, warranting confirmation in adequately powered studies.

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 Δ 0.5 (IQR:−4.2–3.3); p = 0.942; separate-night recordings Δ 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.