Accuracy of Cuffless Ambulatory Blood Pressure Monitors Compared to Cuff-based Monitors in an Ambulatory Elderly Population: A Pilot Study

Mean paired difference between cuffless daytime blood pressure measurements (systolic and diastolic) and cuff-based measurements

Hypertension is extremely common amongst the elderly, typically manifesting as a silent
 disease with potentially devastating consequences if left undetected and untreated. Such
 consequences include stroke, myocardial infarction, kidney and eye disease. Opportunistic
 screening for hypertension is therefore standard in clinical practice. Currently, the
 standard of care for screening in the western world is with 24-hour ambulatory cuff-based
 devices which are often intolerable, particularly for elderly patients.
 
 Several novel cuffless wearables have been developed to overcome the limitations of
 cuff-based monitors. These devices offer significant advantages over cuff-based devices,
 including improved patient tolerance and user acceptability. Numerous cuffless monitors are
 now commercially available. However, validation of such devices is challenging as there is no
 current universal standard for validating such devices.5 This is highlighted by the
 heterogenous and often inadequate study methods used to demonstrate accuracy of commercially
 available cuffless devices for blood pressure measurements. Indeed, the uncertainty about
 their merit is reflected in international guidelines. The 2023 European Society of
 Hypertension guidelines currently do not recommend routine use of such devices in clinical
 practice for evaluation of blood pressure.
 
 There are limited clinical trials comparing 24-hour cuff-based devices directly to cuffless
 devices, and even fewer specifically in an elderly population where they may be particularly
 advantageous due to design features that improve tolerability. This study thus aims to
 address this important gap in the literature to better understand if cuffless devices provide
 reliable blood pressure measurements in the elderly population by directly comparing these
 devices to the current standard of care in blood pressure evaluation. The Aktiia device will
 be used as a surrogate for cuffless wearables while a standard 24-hour ambulatory cuff-based
 device will represent cuff-based devices. The Aktiia device is a cuffless solution worn as a
 bracelet on the wrist. It contains optical sensors which collect photoplethysmography signals
 from arteries in the patient's wrist and uses these to estimate blood pressure. This device
 is commercially available and clinically validated for use in patients up to age 85.