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

OBJECTIVES: 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). METHODS: 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. RESULTS: Compared to ABPM, Aktiia reported higher average SBP for 24-h (difference 4.9 mmHg, 95% CI 1.9, 7.9) and night-time (15.511.8, 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). CONCLUSION: This cuffless wearable device did not accurately track night-time BP decline and results suggested it was unable to track medication-induced BP changes.