Estimation of central systolic blood pressure using an oscillometric blood pressure monitor

Abstract

Current noninvasive techniques for assessing central aortic pressure require the recording of an arterial pressure wave using a high-fidelity applanation tonometer. We therefore developed and validated a novel method to estimate the central aortic systolic pressure using an oscillometric blood pressure monitor alone. Invasive high-fidelity right brachial and central aortic pressure waves, and left-brachial pulse volume plethysmography from an oscillometric blood pressure monitor, were obtained at baseline and 3 min after administration of sublingual nitroglycerin in 100 patients during cardiac catheterization. In the initial 50 patients (Generation Group), Central systolic blood pressure was predicted by a multi-variate prediction model generated from the comprehensive analysis of the invasive brachial pressure wave, including brachial late-systolic shoulder pressure value and parameters related to wave reflection and arterial compliance. Another prediction model was similarly constructed from the noninvasively calibrated pulse volume plethysmography. Both models were validated in the subsequent 50 patients (Validation Group) with results: r¼0.98 (Po0.001) and mean difference¼0.5±4.5 (95% confidence interval À8.3 to 9.3) mm Hg for the invasive model, and r¼0.93 (Po0.001) and mean difference¼À0.1 ± 7.6 (95% confidence interval À15.0 to 14.8) mm Hg for the noninvasive model. Thus, our results indicate that central aortic systolic blood pressure could be estimated by analysis of the noninvasive brachial pressure wave alone from an oscillometric blood pressure monitor.

Validation of a Brachial Cuff-Based Method for Estimating Central Systolic Blood Pressure

“…20 When calibrated with invasive blood pressures, the accuracy of the ARCSolver algorithm meets the data published by Pauca et al, 13 who found a difference between directly recorded cSBP and TF-derived cSBP (from invasively recorded radial pressure waveforms) of 0.0Ϯ4.4 mm Hg. This level of accuracy has been confirmed, when radial tonometric waveforms were calibrated invasively, 21,22 but we are among the first 23 to show that brachial waveforms, acquired with a regular blood pressure cuff, can be used as well. It should be pointed out that our results were obtained against gold-standard highfidelity microtip catheters, thus avoiding potential problems associated with fluid-filled systems, particularly those related to zeroing and damping, and enabling us, because of the high frequency response, to record waveforms accurately.…”

Comparison of two measuring instruments, B-pro and SphygmoCor system as reference, to evaluate central systolic blood pressure and radial augmentation index

“…A number of methods and devices are currently available for estimating central aortic systolic pressure (CASP), either directly from the second peak systolic blood pressure (SBP) corresponding to the radial pulse wave (SBP2) or using a mathematical transfer function that estimates CASP. [8][9][10] The reference device for estimating these measures is the SphygmoCor system (pulse wave analysis). 7,11 Recently, a new system has been developed that estimates derived aortic pressure using an n-point moving average method (B-Pro device s + A-pulse software).…”

Application of the N-Point Moving Average Method for Brachial Pressure Waveform–Derived Estimation of Central Aortic Systolic Pressure

“…Although the noninvasive BAP waveform is only a surrogate BAP waveform, its usefulness has been confirmed in numerous studies. [16][17][18]23 Currently, all international standards, including European Society of Hypertension International Protocol, 24 Association for the Advancement of Medical Instrumentation, 25 and British Hypertension Society, 26 require that the measurement error (mean differences against standards) of tested automatic BP monitors should surpass the minimal requirement of <5±8 mm Hg in validation studies for all BP parameters. The former number refers to systematic bias, which is the group average result for the validity evaluation, and the latter refers to random error, which suggests the scatter of the error.…”

“…The noninvasive BAP waveform was obtained at a cuff pressure of 60 mm Hg in the left arm using a commercially available oscillometric cuff-based device (VP-2000, Colin Corporation, Komaki, Japan). 17 …”

“…Noninvasive CBP is obtained using either tonometry-based 5,14,15 or, more conveniently, cuff-based techniques. [16][17][18] Recently, the capability of the N-point moving average (NPMA) method to estimate central aortic systolic BP (SBP-C) was demonstrated. 19 Using a common denominator related to the sampling frequency, the NPMA is a mathematical low-pass filter that is frequently used in the engineering field for removing random noise from a time series.…”