Comparison of Office-Based Blood Pressure to Daytime Cuffless Blood Pressure in a Population-Based Study

Objective: The latest ESH 2023 guidelines still recommend the use of office blood pressure (BP) measurement for the diagnosis and the follow-up of arterial hypertension. Although cuffless (BP) devices are attractive for patients due their practicality and easy to use, they are not yet recommended by international guidelines. The aim of this project was to test the diagnostic performance of a cuffless device in the adult Swiss population. Design and method: This was a multicentric sub-study nested within a nationwide population-based survey on dietary salt intake in Switzerland. Blood pressure was measured 5 times with a validated oscillometric device (Omron HEM-907) on two separate visits according to a standardized protocol. Cuffless blood pressure using the Aktiia® bracelet was measured intermittently over 24 hours in between visits. The device was calibrated on the first visit using an independent oscillometric device. The average of the last four office BP at each visit was compared to the daytime average BP from the cuffless device with a Bland-Altman plot. Results: Of the 863 individuals included in the study, 511 (46% women, age: 48.6±15.8 years) had their BP taken with both devices. The median number of BP measurements with the cuffless device was 46(IQR 28-90)). Bland and Altman analysis revealed a difference of 0.015 (CI -0.734 to 0.763) in systolic BP and of 0.380 (CI -0.216 to 0.975) in diastolic BP (Figure 1). The agreement for the diagnosis of hypertension was 92.4% with a kappa of 0.61±0.04 for systolic BP and 94.7% with a kappa of 0.50±0.04. Conclusions: In this adult population-based study, the accuracy and the diagnostic performance of a cuffless device were promising. The differences may be secondary to either accuracy or to white coat/masked effect reflecting the different environments of BP measures.