%0 Observational Study
%T Feasibility and measurement stability of smartwatch-based cuffless blood pressure monitoring: A real-world prospective observational study.
%A Han M
%A Lee YR
%A Park T
%A Ihm SH
%A Pyun WB
%A Burkard T
%A Cho MC
%A Camafort M
%A Yang E
%A Stergiou GS
%A Lee HY
%A Seo JM
%A  
%J Hypertens Res
%V 46
%N 4
%D 04 2023
%M 36781979
%F 5.528
%R 10.1038/s41440-023-01215-z
%X Cuffless wearable devices are currently being developed for long-term monitoring of blood pressure (BP) in patients with hypertension and in apparently healthy people. This study evaluated the feasibility and measurement stability of smartwatch-based cuffless BP monitoring in real-world conditions. Users of the first smartwatch-based cuffless BP monitor approved in Korea (Samsung Galaxy Watch) were invited to upload their data from using the device for 4 weeks post calibration. A total of 760 participants (mean age 43.7 ± 11.9, 80.3% men) provided 35,797 BP readings (average monitoring 22 ± 4 days [SD]; average readings 47 ± 42 per participant [median 36]). Each participant obtained 1.5 ± 1.3 readings/day and 19.7% of the participants obtained measurements every day. BP showed considerable variability, mainly depending on the day and time of the measurement. There was a trend towards higher BP levels on Mondays than on other days of the week and on workdays than in weekends. BP readings taken between 00:00 and 04:00 tended to be the lowest, whereas those between 12:00 and 16:00 the highest. The average pre-post calibration error for systolic BP (difference in 7-day BP before and after calibration), was 6.8 ± 5.6 mmHg, and was increased with higher systolic BP levels before calibration. Smartwatch-based cuffless BP monitoring is feasible for out-of-office monitoring in the real-world setting. The stability of BP measurement post calibration and the standardization and optimal time interval for recalibration need further investigation.