Abstract 20656: Calibration With Mean Blood Pressure is Essential for Utilization of Brachial Pulse Wave Analysis-Based Ambulatory Central Blood Pressure Monitor for Cardiovascular Patients
Background: Central blood pressure (cBP) shows actual pressure load on the heart and proximal large arteries, thus it is deemed to be superior to brachial blood pressure in predicting cardiovascular events.
Recently indirect measurement of cBP was enabled by analysis of arterial pulse wave, resulting in its popular use in the clinical setting. Even Ambulatory central Blood Pressure Monitor (AcBPM) implemented with this program, such as ARC Solver algorithm, is now put into practical use.
There remain several issues regarding indirect measurement of cBP.
There is no consistent agreement on the calibration mode that is indispensable for calculation process. Not all the patient are qualified to interpret the attained data due to lacking of validation in the specific disease population or standardized reference data.
Object: To determine optimal calibration mode of the AcBPM with ARC Solver algorithm, we compared the accuracy of attained data between two available modes. We also sought to find subpopulation for which this instrument is most suitable.
Method: For 142 patients who underwent elective coronary angiography in our hospital, we simultaneously measured invasive and noninvasive central blood pressure parameters such as central systolic blood pressure (cSBP), central pulse pressure (cPP), pulsatility. We calibrated the noninvasive data with systolic and diastolic BP(Cal1) or mean and diastolic BP(Cal2). Then we compared the accuracy between two modes. After excluding perturbing factors that can affect data acquisition, we analyzed the same way.
Results: Cal2 consistently showed better linear correlation in all the parameters (Cal1 vs Cal2: cSBP 0.78 vs 0.81, cPP 0. 64 vs 0.73, Pulsatility 0.51 vs 0.65). Cal2 also showed much less error in the same parameters (Cal1 vs Cal2: 18.8±15.5 vs -4.5±15.5 mmHg, cPP 32.2±16.4 vs 10.6±15.3mmHg, Pulsatility0.30±0.15 vs 0.10±0.14). After excluding perturbing factors, accuracy of these parameters showed little change, whereas additional exclusion of cSBP over 180mmHg further improved its accuracy (-2.0±11.1mmHg).
Conclusions: Use of Cal2 is essential for clinical application of AcBPM with ARC Solver algorithm.
Extremely high cSBP value should be taken as outlier.
Author Disclosures: T. Shoji: None. S. Okada: None. A. nakagomi: None. Y. Kobayashi: None.
- © 2014 by American Heart Association, Inc.