A randomized crossover clinical trial comparing 24-h blood pressure measurements from two different cuffless wrist ambulatory monitors with cuffed ambulatory monitoring for translation to clinical practice: Rationale and Design of Continuum BP study

Study objective: Cuffless blood pressure (BP) measuring devices have potential to improve screening, diagnosis and management of hypertension. However, translation of BP estimates from such devices to cuffed BP readings, which currently inform hypertension and cardiovascular risk management guidelines, remains uncertain. We designed Continuum BP to understand how BP measurements from two independent CE-marked wrist worn devices can be contextualized for clinical use. Design: Prospective observational randomized crossover study. Setting: William Harvey Heart Centre, Queen Mary, University of London. Participants: 48 adult volunteers. Interventions: Aktiia Bracelet (utilizing photoplethysmography) and the Healthstats BPro Evo (utilizing applanation tonometry) worn independently, each alongside cuffed OnTrak ambulatory BP monitor (ABPM), across two 24 h non-overlapping periods of monitoring by the same individuals. Main outcome measures: Difference between average daytime, 24 h and night-time systolic and diastolic BP estimated by each cuffless device and ABPM; and acceptability of wearing each device type compared to ABPM. Data will be used to estimate a numerical calibration of readings from each of Aktiia/Healthstats BPro Evo to ambulatory BP. Conclusion: Continuum BP received ethical approval from West of Scotland National Health Service research ethics committee (24/WS/0131) and was advertised across Queen Mary University of London campuses and affiliated hospitals. Recruitment is complete. Collected data is being analysed. Findings will enable physicians to interpret and use cuffless BP from two commonly available wrist devices in routine practice, and disseminated through study website, scientific meetings and publications. Trial registration https://clinicaltrials.gov/ (NCT06573801).