New Method to Estimate Central Systolic Blood Pressure From Peripheral Pressure: A Proof of Concept and Validation Study

Abstract

Objective: The non-invasive estimation of central systolic blood pressure (cSBP) is increasingly performed using new devices based on various pulse acquisition techniques and mathematical analyses. These devices are most often calibrated assuming that mean (MBP) and diastolic (DBP) BP are essentially unchanged when pressure wave travels from aorta to peripheral artery, an assumption which is evidence-based. We tested a new empirical formula for the direct central blood pressure estimation of cSBP using MBP and DBP only (DCBP = MBP2/DBP).Methods and Results: First, we performed a post-hoc analysis of our prospective invasive high-fidelity aortic pressure database (n = 139, age 49 ± 12 years, 78% men). The cSBP was 146.0 ± 31.1 mmHg. The error between aortic DCBP and cSBP was −0.9 ± 7.4 mmHg, and there was no bias across the cSBP range (82.5–204.0 mmHg). Second, we analyzed 64 patients from two studies of the literature in whom invasive high-fidelity pressures were simultaneously obtained in the aorta and brachial artery. The weighed mean error between brachial DCBP and cSBP was 1.1 mmHg. Finally, 30 intensive care unit patients equipped with fluid-filled catheter in the radial artery were prospectively studied. The cSBP (115.7 ± 18.2 mmHg) was estimated by carotid tonometry. The error between radial DCBP and cSBP was −0.4 ± 5.8 mmHg, and there was no bias across the range.Conclusion: Our study shows that cSBP could be reliably estimated from MBP and DBP only, provided BP measurement errors are minimized. DCBP may have implications for assessing cardiovascular risk associated with cSBP on large BP databases, a point that deserves further studies.

Commentary: Direct estimation of central aortic pressure from measured or quantified mean and diastolic brachial blood pressure: agreement with invasive records

“…A notable novelty of the study is its exploration of DCBP's accuracy and precision in relation to prevailing aoSBP levels. The pressure-dependent errors documented by the authors at the brachial level (2) have not been observed at the aortic or radial levels (1,17), suggesting the necessity for additional explanation and confirmation. The authors have addressed some limitations of the study, but there are a few other important ones that also require consideration.…”

“…The authors conclude that the utility of the DCBP method depends significantly on both the approach used to estimate brachial mean blood pressure (bMBP) and the aoSBP level. We appreciate the authors' interest in our proposal (1) and commend them for their wellexecuted study and interesting results. In this commentary, we will emphasize the rationale for DCBP, discuss the way MBP is estimated in large arteries, explore the strengths and limitations of the current study (2), and suggest potential areas for further research.…”

Impact of a cuff‐based device calibration method on the agreement between invasive and noninvasive aortic and brachial pressure

“…The Bland‐Altman derived mean error was categorised into four bands (ranges) according to the rounded absolute values: (1) 0–5 mmHg, measurements considered 'very accurate' (no error of clinical relevance; green); (2) 6–10 mmHg, measurements considered 'slightly inaccurate' (yellow); (iii) 11–15 mmHg, measurements considered 'moderately inaccurate' (orange); and (4) >15 mmHg, measurements considered 'very inaccurate' (red) (Table 3) (Chemla et al, 2021; OʼBrien et al, 2002).…”

“…The Bland-Altman derived mean error was categorised into four considered 'moderately inaccurate' (orange); and (4) >15 mmHg, measurements considered 'very inaccurate' (red) (Table 3) (Chemla et al, 2021;OʼBrien et al, 2002).…”

Estimation of Central Systolic Blood Pressure from Peripheral Pressure Waves using a Novel Second Systolic Pressure-Based Method in Normal and Heritable Hypercholesterolemic Rabbits

“…Some attempts have been made to estimate cSBP without GTF from peripheral pressure or flow waves [16][17][18] . Miyashita et al 19) reported that during cardiac catheterization in 20 patients, noninvasive radial pSBP2 underestimated invasive micromanometric cSBP in conditions of lower peripheral AI or greater pulse pressure amplification, which was broadly corrected by replacing pSBP2 with the simple arithmetic mean of pSBP and pSBP2 (pSBPm).…”