Heart failure (HF) remains a leading cause of morbidity and mortality despite substantial advances in guideline-directed medical therapy [1]. Alongside therapeutic developments, cardiac implantable electronic devices (ICDs and CRT-Ds) have evolved from rhythm surveillance tools into platforms capable of continuously collecting physiological information relevant to HF status, including heart rate (HR), heart rate variability (HRV), physical activity and thoracic impedance. These remotely acquired parameters have generated considerable interest as potential digital biomarkers that could provide continuous assessment of patient status, facilitate personalised management and potentially detect treatment response before conventional clinical or imaging endpoints become apparent [2–5].
