Implications of Wearable Sleep Health Technology for Cardiovascular Health Assessment and Interventions: A Narrative Review.

Sleep health is a multidimensional component of cardiovascular health, and modulating sleep as a cardiometabolic risk factor requires accurate measurement. Numerous technologies have emerged in the last 50 years to longitudinally characterize sleep over time in ambulatory settings, and their use by the public has grown. The impact of this democratization of health information through wearables has not been adequately explored in the literature. This narrative review equips clinicians and researchers with a mechanistic understanding of wearable sleep health technology to augment precision cardiovascular health assessment and intervention. Peer-reviewed literature was synthesized from PubMed, spanning foundational actigraphy studies through recent multisensor and electroencephalography-based device evaluations, with emphasis on device performance against polysomnography. Consistent with a narrative review, sources were selected through domain expertise rather than systematic screening. Wearable devices measure peripheral proxies to determine if the wearer is awake or asleep. The simplest method, actigraphy, uses motor activity to differentiate sleep from wake. Newer multisensor devices use actigraphy in addition to other physiological proxies of sleep (eg, heart rate, heart rate variability, skin temperature). Current device heterogeneity can diminish the validity of conclusions that can be drawn from wearable data; thus, performance evaluation against polysomnography is vital to determine the accuracy, sensitivity, and specificity of a device. Across evaluations, devices consistently show high sensitivity for detecting sleep but lower specificity for detecting wake; several consumer devices nonetheless perform comparably to research-grade actigraphy, some have received regulatory authorization for sleep apnea screening, and headband electroencephalography systems approach polysomnography-level staging. Wearable devices show promise as objective anchors to drive provider-patient interactions in cardiometabolic lifestyle interventions, offering scalable, valid measurement tools to quantify sleep health, and inform cardiovascular risk assessment. Interpretation requires awareness of structural device limitations, optimally through the understanding of the physiological concepts that underpin the function of these devices.