Iterative calibration of a wrist-worn blood pressure monitor to direct central aortic pressures improved systolic measurement accuracy by 33% and diastolic accuracy by 73%.
Observational (n=20)
No
Does iterative calibration of a wrist-worn blood pressure monitor using direct intra-arterial measurements improve the accuracy of noninvasive blood pressure readings in patients undergoing cardiac catheterization?
Iterative calibration of a wrist-worn blood pressure device using direct central aortic pressures significantly improves its accuracy, potentially reducing the treatment gap in hypertension management.
Absolute Event Rate: 7.2% vs 10.8%
p-value: p=0.97
BACKGROUND: Clinical guidelines recommend monitoring of blood pressure at home using an automatic blood pressure device for the management of hypertension. Devices are not often calibrated against direct blood pressure measures, leaving health care providers and patients with less reliable information than is possible with current technology. Rigorous assessments of medical devices are necessary for establishing clinical utility. OBJECTIVE: The purpose of our study was 2-fold: (1) to assess the validity and perform iterative calibration of indirect blood pressure measurements by a noninvasive wrist cuff blood pressure device in direct comparison with simultaneously recorded peripheral and central intra-arterial blood pressure measurements and (2) to assess the validity of the measurements thereafter of the noninvasive wrist cuff blood pressure device in comparison with measurements by a noninvasive upper arm blood pressure device to the Canadian hypertension guidelines. METHODS: The cloud-based blood pressure algorithms for an oscillometric wrist cuff device were iteratively calibrated to direct pressure measures in 20 consented patient participants. We then assessed measurement validity of the device, using Bland-Altman analysis during routine cardiovascular catheterization. RESULTS: The precalibrated absolute mean difference between direct intra-arterial to wrist cuff pressure measurements were 10.8 (SD 9.7) for systolic and 16.1 (SD 6.3) for diastolic. The postcalibrated absolute mean difference was 7.2 (SD 5.1) for systolic and 4.3 (SD 3.3) for diastolic pressures. This is an improvement in accuracy of 33% systolic and 73% diastolic with a 48% reduction in the variability for both measures. Furthermore, the wrist cuff device demonstrated similar sensitivity in measuring high blood pressure compared with the direct intra-arterial method. The device, when calibrated to direct aortic pressures, demonstrated the potential to reduce a treatment gap in high blood pressure measurements. CONCLUSIONS: The systolic pressure measurements of the wrist cuff have been iteratively calibrated using gold standard central (ascending aortic) pressure. This improves the accuracy of the indirect measures and potentially reduces the treatment gap. Devices that undergo auscultatory (indirect) calibration for licensing can be greatly improved by additional iterative calibration via intra-arterial (direct) measures of blood pressure. Further clinical trials with repeated use of the device over time are needed to assess the reliability of the device in accordance with current and evolving guidelines for informed decision making in the management of hypertension. TRIAL REGISTRATION: ClinicalTrials.gov NCT03015363; https://clinicaltrials.gov/ct2/show/NCT03015363 (Archived by WebCite at http://www.webcitation.org/6xPZgseYS).
Melville et al. (Wed,) conducted a observational in Patients undergoing diagnostic cardiac catheterization (n=20). Wrist-worn blood pressure monitor with central aortic calibration vs. Precalibrated wrist cuff and direct intra-arterial blood pressure measurements was evaluated on Absolute mean difference in systolic blood pressure compared to direct intra-arterial measurement (p=0.97). Iterative calibration of a wrist-worn blood pressure monitor to direct central aortic pressures improved systolic measurement accuracy by 33% and diastolic accuracy by 73%.
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