Validation of a popular consumer-grade cuffless blood pressure device for continuous 24 h monitoring.

AIMS

Hypertension is a leading cause of death worldwide, yet many hypertensive cases remain undiagnosed. Wearable, cuffless blood pressure (BP) monitors could be deployed at scale, but their accuracy remains undetermined.

METHODS AND RESULTS

This study validated a popular consumer-grade wearable BP monitor (W-BPM, Aktiia), using a medical-grade ambulatory device (A-BPM, Mobil-O-Graph), for reference. Thirty-one participants (aged 19-62 years, 17 (55%) females, in office BP 121 ± 15 over 77 ± 12 mmHg) simultaneously wore both devices for 24 h. Systolic BP (SBP), diastolic BP (DBP), and heart rate (HR) were measured in pre-set intervals by the A-BPM and at rest by the W-BPM. Agreement was assessed using standard methods. Accuracy in identifying high BP (mean 24 h SBP/DBP > 130/80 mmHg) was assessed. Compared to A-BMP, mean SBP and DBP tended to be slightly lower during the day and not significantly different at night. Nocturnal BP dipping and BP variability were significantly underestimated by the W-BPM. Agreement between the two devices was poor to moderate (limits of agreement of about -30/+30 mmHg for SBP and -20/+15 mmHg for DBP, correlation coefficients between 0.20 and 0.42). Sensitivity and specificity for high BP detection were around 50% and 80%, respectively. Limiting the analysis to measures taken in similar conditions (within 10 min and with HR within ±10 b.p.m.) did not improve agreement.

CONCLUSION

Low agreement suggests that the cuffless device may not be a suitable replacement for standard 24 h cuff-based ambulatory monitoring. Further data are required to assess the clinical role of cuffless BP monitors.