Evaluation of the ability of a commercially available cuffless wearable device to track blood pressure changes

Cuffless wearable blood pressure (BP) devices may allow detailed evaluation of BP for prolonged periods, but their ability to accurately track BP changes is uncertain. We investigated whether a commercially available cuffless wearable device tracks: 24-h systolic (SBP) and diastolic BP (DBP) compared to conventional ambulatory monitoring (ABPM); and antihypertensive medication-induced BP changes compared to cuff-based home BP monitoring (HBPM).

We fitted 41 participants (32% females, 58 ± 14 years, 80% hypertensive) with a wrist-wearable cuffless BP device (Aktiia) continuously for 6-12 days. At the beginning and the end of this period, 24-h ABPM was performed. Three participants with hypertension (one female; 60 ± 8 years) wore the Aktiia device and performed HBPM continuously one week before and 2 weeks after antihypertensive medication uptitration.

Compared to ABPM, Aktiia reported higher average SBP for 24-h (difference 4.9 mmHg, 95% CI [1.9, 7.9]) and night-time (15.5[11.8, 19.1] mmHg; all P ≤ 0.01), but similar daytime (1.0 [-1.8, 3.8] mmHg; P = 0.48). Similarly, average cuffless DBP was higher for 24-h (4.2 [2.3, 6.0] mmHg) and night-time (11.8 [9.5, 14.1] mmHg; both P  < 0.001), but similar during daytime (1.4 [-0.4, 3.23] mmHg; P  = 0.13). Aktiia also reported reduced night-time dip for SBP (difference 14.2 [12.1, 16.3] mmHg) and DBP (10.2 [8.5, 11.9] mmHg; both P  < 0.001). The average medication-induced SBP/DBP decline after 2 weeks of uptitration was -1.0/-0.8 mmHg with Aktiia vs. -19.7/-11.5 mmHg with HBPM ( P  = 0.03 for difference).

This cuffless wearable device did not accurately track night-time BP decline and results suggested it was unable to track medication-induced BP changes.