1] The Joanna Briggs Institute, Faculty of Health Sciences, The University of Adelaide, Adelaide, Australia  Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei, Taiwan  Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan  Department of Medicine, National Yang-Ming University, Taipei, Taiwan.
The prognostic value of central aortic pulse pressure (PP-C) may have been underestimated due to its measurement inaccuracy. We aimed to investigate the accuracy of noninvasive brachial cuff-based estimation of PP-C by a generalized transfer function (GTF) or a novel pulse wave analysis (PWA) approach to directly estimate PP-C.Methods
Invasive high-fidelity right brachial and central aortic pressure tracings, and left brachial pulse volume plethysmography (PVP) waveforms from an oscillometric blood pressure (BP) monitor were all digitized simultaneously in 40 patients during cardiac catheterization. An aortic-to-brachial GTF and a PWA multivariate prediction model using the PVP waveforms calibrated to brachial cuff systolic BP (SBP) and diastolic BP(DBP) were constructed. Accuracy of the two methods was examined in another 100 patients against invasively measured PP-C.ResultsThe error of cuff PP in estimating PP-C was 1.8 ± 12.4 mm Hg. Application of the GTF on noninvasively calibrated PVP waveforms produced reconstructed aortic pressure waves and PP-C estimates with errors of -3.4 ± 11.6 mm Hg (PP-C = reconstructed aortic SBP - aortic DBP) and -2.3 ± 11.4 mm Hg (PP-C = reconstructed aortic SBP - cuff DBP), respectively. The observed systematic errors were proportional to the magnitudes of PP-C. In contrast, the error of the PWA prediction model was 3.0 ± 7.1 mm Hg without obvious proportional systematic error.Conclusions
Large random and systematic errors are introduced into the PP-C estimates when PP-C is calculated as the difference between the estimated central SBP and central or cuff DBP. The accuracy can be improved substantially with the novel PWA approach.American Journal of Hypertension 2012; doi:10.1038/ajh.2012.116.
[Show abstract][Hide abstract] ABSTRACT: Oscillometric central blood pressure (CBP) monitors have emerged as a new technology for blood pressure (BP) measurements. With a newly proposed diagnostic threshold for CBP, we investigated the diagnostic performance of a novel CBP monitor.
We recruited a consecutive series of 138 subjects (aged 30-93 years) without previous use of antihypertensive agents for simultaneous invasive and noninvasive measurements of BP in a catheterization laboratory. With the cutoff (CBP ≥130/90mm Hg) for high blood pressure (HBP), the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the novel CBP monitor were calculated with reference to the measured CBP. In comparison, the diagnostic performance of the conventional cuff BP was also evaluated.
The noninvasive CBP for detecting HBP in a sample with a prevalence of 52% showed a sensitivity of 93% (95% confidence interval (CI) = 91-95), specificity of 95% (95% CI = 94-97), PPV of 96% (95% CI = 94-97), and NPV of 93% (95% CI = 90-95). In contrast, with cuff BP and the traditional HBP criterion (cuff BP ≥140/90mm Hg), the sensitivity, specificity, PPV, and NPV were 49% (95% CI = 44-53), 94% (95% CI = 92-96), 90% (95% CI = 86-93), and 63% (95% CI 59-66), respectively.
A stand-alone oscillometric CBP monitor may provide CBP values with acceptable diagnostic accuracy. However, with reference to invasively measured CBP, cuff BP had low sensitivity and NPV, which could render possible management inaccessible to a considerable proportion of HBP patients, who may be identifiable through noninvasive CBP measurements from the CBP monitor.
American Journal of Hypertension 01/2014; 27(3). DOI:10.1093/ajh/hpt282 · 2.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives:
Noninvasive brachial systolic blood pressure (nSBP-B) usually approaches invasive central systolic blood pressure (iSBP-C) with a high correlation. Whether nSBP-B is an accurate estimate of iSBP-C remained to be investigated. Thus, this study aimed to compare the errors of nSBP-B and noninvasive central systolic blood pressure (nSBP-C) with different techniques in estimating iSBP-C.
Simultaneous invasive high-fidelity central aortic pressure waveforms and the noninvasive left brachial pulse volume recording (PVR) waveform were recorded in a Generation group (N = 40) and a Validation group (N = 100). The accuracy of the noninvasive estimates of iSBP-C obtained from analysis of the calibrated PVR waveform using the generalized transfer function (GTF), pulse waveform analysis (PWA), and N-point moving average (NPMA) methods was examined in the Validation group by calculating the mean absolute error (MAE).
In Generation group, the MAE was 4.6±4.1mm Hg between nSBP-B and invasive brachial SBP, and 6.8±5.5mm Hg between nSBP-B and iSBP-C. In comparison, the MAE of between iSBP-C and nSBP-C with PWA, NPMA, and GTF were 5.5±4.5, 5.8±4.9, and 5.9±5.0mm Hg, respectively. In Validation group, the MAE of nSBP-B (6.9±4.6mm Hg) for estimating iSBP-C was significantly greater than that of PWA (5.0±3.4mm Hg) and NPMA (6.1±4.4mm Hg), and GTF (6.1±4.9mm Hg). The percentage of absolute band error ≤5mm Hg was 62% for nSBP-B, 69% for GTF, 83% for PWA, and 69% for NPMA.
The accuracy of nSBP-B was inferior to the n SBP-C measures in estimating iSBP-C.
American Journal of Hypertension 10/2015; DOI:10.1093/ajh/hpv164 · 2.85 Impact Factor
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