S-58-2: CUFFLESS WEARABLE 24-HOUR BLOOD PRESSURE MONIT ORING VERSUS STANDARD AMBULATORY MONITORING

Abstract

Objective: Cuffless wearable blood pressure (BP) monitors have great potential in assessing 24-hour BP without user disturbance for weeks and months. However, it is uncertain whether these devices can accurately track BP changes during usual daily activities and sleep as with standard 24-hour ambulatory BP monitoring (ABPM). We assessed daytime and nighttime BP using a commercially available cuffless wearable BP device versus classic ABPM. Design and method: We included 45 individuals (age 58 ± 14 years [mean ± SD], 33% female, 80% hypertensive) in two centres (Perth, Australia; Athens, Greece). Participants used a cuffless wearable BP monitor (Aktiia, Switzerland) continuously for 7–10 days and 24-hour ABPM (MicroLife WatchBP O3, Switzerland) on the first and the last day of cuffless BP monitoring. Daily 24-hour, daytime, and nighttime BP values were averaged across the total study days for the cuffless device and across the two ABPM days. Results: The cuffless device reported higher systolic BP for 24-hours by 6.8 mmHg, 95%CI [3.7, 9.7], daytime by 3.8 mmHg [1.0, 6.7], and nighttime by 17.5 mmHg [13.6, 21.4] (all p < 0.01). Cuffless 24-hour diastolic BP was comparable with ABPM (difference 1.2 mmHg, 95%CI [-1.0, 3.5]), as was daytime diastolic BP (-0.8 mmHg [-3.0, 1.3]) (both p. < 27). However, the cuffless device reported higher nighttime diastolic BP by 9.2 mmHg, 95%CI [6.3, 12.2] (p < 0.001). Nighttime dip as measured by the cuffless device, namely systolic BP (-5.1 mmHg, 95%CI [-13.7, 3.6]) and diastolic BP (-3.8 mmHg [-11.6, 4.2]) were substantially less than ABPM (systolic BP dip: -18.0 mmHg [-35.5, -1.2]; diastolic BP dip: -13.8 mmHg [-27.2, -0.8]). The cuffless device identified 44 nighttime non-dippers (defined as a relative dip < 10%) for systolic BP and 42 non-dippers for diastolic BP, compared to 10 non-dippers for both systolic and diastolic BP as identified by ABPM (both comparisons p < 0.001). Conclusions: The Aktiia cuffless wearable BP device considerably overestimated average systolic BP compared to classic ABPM and was unable to adequately track diurnal BP variation.