RESUMO
Hypertension remains the leading risk factor for death worldwide. Despite its prevalence, success of blood pressure (BP) management efforts remains elusive, and part of the difficulty lies in the tool still used to diagnose, measure, and treat hypertension: the sphygmomanometer introduced by Samuel Siegfried Karl von Basch in 1867. In recent years, there has been an explosion of devices attempting to provide estimates of BP without a cuff, overcoming many limitations of cuff-based BP monitors. Unfortunately, the differences in underlying technologies between traditional BP cuffs and newer cuffless devices, as well as hesitancy of changing a well-implemented standard, still generate understandable skepticism about and reluctance to adopt cuffless BP monitors in clinical practice. This guidance document aims to navigate the scientific and medical communities through the types of cuffless devices and present examples of robust BP data collection which are better representations of a person's true BP. It highlights the differences between data collected by cuffless and traditional cuff-based devices and provides an initial framework of interpretation of the new cuffless datasets using, as an example, a CE-marked continual cuffless BP device (Aktiia BP Monitor, Aktiia, Switzerland). Demonstration of novel BP metrics, which have the potential to change the paradigm of hypertension diagnosis and treatment, are now possible for the first time with cuffless BP monitors that provide continual readings over long periods. Widespread adoption of continual cuffless BP monitors in healthcare will require a collaborative and thoughtful process, acknowledging that the transition from a legacy to a novel medical technology will be slow. Finally, this guidance concludes with a call to action to international scientific and expert associations to include cuffless BP monitors in original scientific research and in future versions of guidelines and standards.
RESUMO
OBJECTIVE: The objective of this study was to compare the systolic (S) and diastolic (D) blood pressure (BP) estimations from a new optical device at the wrist with invasive measurements performed on patients scheduled for radial arterial catheterization in the ICU. Optical signals were automatically processed by a library of algorithms from Aktiia SA (OBPM - optical blood pressure monitoring algorithms). METHODS: A total of 31 participants from both sexes, aged 32-87 years, were enrolled in the study (NCT03837769). The measurement protocol consisted of the simultaneous recording of reflective photoplethysmographic signals (PPG) from the cuffless optical device and the reference BP values recorded by a contralateral radial arterial catheter. From the 31 participants, 23 subjects whose reference data quality requirements were adequate were retained for further analysis. The PPG signals from these patients were then automatically processed by the Aktiia OBPM library of algorithms, which generated uncalibrated estimates of SBP and DBP. After the automatic assessment of optical signal quality, 326 pairs of uncalibrated SBP and DBP determinations from 16 patients were available for analysis. These values were finally transformed into calibrated estimations (in mmHg) using arterial catheter SBP and DBP values, respectively. RESULTS: For SBP, a mean difference (±SD) of 0.0 ± 7.1 mmHg between the arterial catheter and the optical device values was found, with 95% limits of agreement in the Bland-Altman method of -11.9 to + 12.2 mmHg (correlation of r = 0.87, P < 0.001). For DBP, a mean difference (±SD) of 0.0 ± 2.9 mmHg between arterial catheter and the optical device values was found, with 95% limits of agreement in the Bland-Altman method of -4.8 to + 5.5 mmHg (correlation of r = 0.98, P < 0.001). CONCLUSION: SBP and DBP values obtained by radial artery catheterization and those obtained from optical measurements at the wrist were compared. The new optical technique appears to be capable of replacing more traditional methods of BP estimation.