Comparative Evaluation of the Aktiia Cuffless Monitor and Standard 24-H Ambulatory Blood Pressure Monitor

Objective: Cuffless blood pressure (BP) monitors provide an innovative approach for BP assessment, transcending the episodic nature of traditional cuff-based, oscillometric modalities like ambulatory BP monitors (ABPM). However, the performance of these cuffless devices compared to their cuff-based counterparts remains debated. In this study, BP readings from a continuous cuffless BP monitor were compared against those from a standard 24-hour ABPM. Design and method: The study enrolled 63 subjects (NCT04548986, 53.1±7.2 years, 21.2% female, arm circumference 29.0±2.5 cm) participating in a 12-week cardiac rehabilitation (CR) program (Réseau Hospitalier Neuchâtelois, Switzerland). Comparisons encompassed 24-h, daytime (9am– 9pm), and night-time (11pm–7am) systolic and diastolic BP (SBP, DBP) using a 7-day average BP measurement from a cuffless monitor (Aktiia SA, Switzerland) overlapping with a 1-day average from the ABPM (Dyasis 3, Novacor, France), both recorded at the start and end of the CR program. Two sessions were analyzed: session 1 compared the first day's ABPM data with the first week's Aktiia data; session 2 compared the last day's ABPM data with the last week's Aktiia data. Only sessions with at least 20 daytime and 7 night-time valid measurements from both monitoring modalities were included in this analysis. Results: From the initial cohort, 51 subjects fulfilled the requirements of data availability of this analysis (Figure 1, 44 in session 1, 35 in session 2). No significant differences were found between Aktiia and ABPM monitors in 24-h and daytime SBP readings (24-hour: mean ± SD 95% CI 2.6±12.3 -0.2, 5.4 mmHg, correlation r=0.57, P=0.06; daytime: 1.2±12.4 -1.6, 4.0 mmHg, r=0.60, P=0.38). However, night-time SBP readings showed more pronounced differences (12.5±14.4 9.3, 15.8 mmHg, r=0.39, P<0.001). DBP readings were significantly different but within clinical acceptance for 24-h and daytime (24-hour: -2.9±7.9 -4.7, -1.1 mmHg, r=0.63, P=0.002; daytime: -3.1±8.2 -5.0, -1.3 mmHg, r=0.64, P=0.001), with notable night-time differences (4.1±8.5 2.2, 6.0 mmHg, r=0.57, P<0.001). Conclusions: The findings reveal the Aktiia monitor's promising performance in continuous, long-term BP monitoring, especially during daytime, while noting important differences at night. Further research is underway to investigate nocturnal measurements.