O20 CURRENT 24-HOUR AMBULATORY BLOOD PRESSURE TECHNOLOGIES SHOULD BE RECONSIDERED AS THE REFERENCE STANDARD FOR VALIDATION OF CUFFLESS BLOOD PRESSURE DEVICES

Background and Objective: Recommendations for the validation of cuffless blood pressure (BP) devices were recently released by the European Society of Hypertension (ESH). In this recommendation, 24-hour ambulatory BP monitoring (ABPM) is the reference standard for a newly proposed ‘awake-asleep’ accuracy test. However, this reference standard may be inappropriate because ABPM is subject to measurement insecurities, and it is unknown if it would pass the awake-asleep test. Therefore, the aim of this study was to determine if ABPM itself would pass the awake-asleep test recommended for validation of cuffless BP devices. Methods: Dual arm, simultaneous ABPM were recorded using two identical cuff-based devices (TM-2430, A&D, Japan) among 46 healthy adults (22±2.3 years; 54% female). The awake-asleep test was defined as the difference between the left arm ABPM minus right arm ABPM for assessing the change in BP between awake-asleep time (ESH recommendations: mean difference ± SD ≤5±8 mmHg, correlation r>0.7 for test and reference values; awake-asleep BP components calculated based on personalized sleeping times). Measurement artefacts were identified by analysis of the cuff deflation pressure curves and hydrostatic pressure differences (body position) between the cuffs. Results: ABPM did not pass the awake-asleep test due to higher than acceptable measurement variability for systolic BP, -0.1±8.6 mmHg, r=0.69 and partially met requirements for diastolic BP, -0.7±5.9 mmHg, r=0.63. After correction for measurement artefacts and hydrostatic pressure differences, ABPM passed the awake-asleep test for systolic BP (-1.7±5.0 mmHg, r=0.76) but still did not meet requirements for diastolic BP due to insufficient correlation (r=0.64). Conclusion: In this analysis, ABPM itself did not meet the awake-asleep test criteria recommended by the ESH. Using current ABPM technologies as a reference standard for cuffless BP validation protocols may need to be reconsidered and they need improvement before use for this purpose. Improving ABPM through better measurement artefact detection could be an initial solution which would also improve its value for clinical decision making.