Zemin Kuang Beijing Anzhen Hospital, Capital Medical University, Beijing, China

1. Scientificity and Feasibility Study of Non-Invasive
Central Arterial Pressure Measurement in
Hypertensive Patients in Different Activity States
Beijing Anzhen Hospital, Capital Medical University,
Beijing, China

2. Background（1/2）
Central Arterial Pressure
• An independent predictor of cardiovascular and cerebrovascular
diseases[1,2]
• A better predictor of cardiovascular events than brachial arterial
blood pressure[1,3]
• Significantly associated with coronary artery diseases (CAD) [3,4]
Measurement: Office single time VS ambulatory or continuous
monitoring
• To obtain more comprehensive and accurate data
• At different time points and under different conditions
• White coat hypertension, masked hypertension (MH) and isolated
nocturnal hypertension
Brachial artery
blood pressure
Central arterial
pressure
[1] Dong Y, Jiang L, Wang X, et al. Central rather than brachial
pressures are stronger predictors of cardiovascular outcomes:
a longitudinal prospective study in a Chinese population[J]. The
Journal of Clinical Hypertension, 2020, 22(4): 623-630.
[2] Sánchez R, Pessana F, Lev G, et al. Central blood pressure
waves assessment: a validation study of non-invasive aortic
pressure measurement in human beings[J]. High Blood
Pressure & Cardiovascular Prevention, 2020, 27: 165-174.
[3] 孙玉,郭守玉,龙明智.中心动脉压与靶器官损害的研究进展[J].
心血管病学进展, 2023, 44(5):457-459.
[4] 匡泽民,唐欣颖,奉淑君,等.无创中心动脉压与靶器官损害研究
进展[J].中华高血压杂志 2019(9):4.

3. Background（2/2）
Ambulatory blood pressure monitoring[1,2]
• Brachial à Central Arterial ?
Requires further verification: the scientific validity and clinical feasibility[3,4]
• To measure in different states: uneven breathing and light physical activities
• The scientificity and feasibility for using SphygmoCor®
to measure central arterial
pressure under different conditions need to be verified.
[1] European Society of Hypertension Working Group on Blood Pressure Monitoring. European Society of Hypertension position paper on ambulatory blood
pressure monitoring. J Hypertens 2013; 31(9):1731-1768.
[2] European Society of Hypertension Working Group on Blood Pressure Monitoring. European Society of Hypertension practice guidelines for ambulatory
blood pressure monitoring. J Hypertens 2014; 32(7):1359-1386.
[3] Is isolated nocturnal hypertension a novel clinical entity ? Findings from a Chinese population study. Hypertension 2007; 50:333-339.
[4] Prognostic value of isolated nocturnal hypertension in 8711 subjects from 10 populations. J Hypertens 2010; 28(10):2036-2045.

4. Aims and Objectives
• Use SphygmoCor®
to measure the central arterial pressure of the patients, and compare the difference between
single-point measurement and multi-point measurement of central arterial pressure for patients in resting state.
• Simulate central arterial pressure monitoring under different activity states by asking the patients to perform uneven
breathing and light physical activities. Evaluate the scientificity and feasibility of clinical operation of SphygmoCor® in
measuring central arterial pressure under different activity states of patients.
• Compare and analyze he blood pressure data of the patients under different activity states.
• Constructing a database of non-invasive arterial vascular function changes in hypertensive patients.
• Establishing a standardized procedure for measuring central arterial pressure in different activity states.
• Establishing a personalized disease risk prediction model based on central arterial pressure.
Aims
Objectives

5. Methods (1/4)
Technology and Equipment
• SphygmoCor® (AtCor Medical, Australia) : A non-invasive cardiac
monitoring device based on a hemodynamic mechanism that can accurately
measure central arterial pressure.
• The device estimates central arterial pressure by analyzing peripheral pulse
waveform and calculating PWV, combined with individual physiological
parameters (such as age, sex, height and weight).
• The measurement results of the device are highly consistent with those of
the traditional invasive floating catheter, with a precision of 99% and an
error of less than 1mmHg.

6. Methods (2/4)
Study Design / Data Collection:
1. Age, gender, height, weight, medical history, medication use and other basic information of
the patients were recorded. According to age, the patients were divided into the elderly
group and the young and middle-aged group.
2. Perform multiple measurements of central arterial pressure using a SphygmoCor® as the
following:
a. Ask the patients to rest for 5-10 minutes before their first measurement, and
measure their central arterial pressure while they remain in resting state, take 3
measurements in total at an interval of 2 minutes between each measurement.
b. Ask the patients to take 6 deep breaths (within about 1 minute) [1,2] , then measure
their central arterial pressure, followed by a resting period of 2 minutes. Repeat the
process for 2 more times to collect a total of 3 measurements under uneven
breathing state.
c. Ask the patients to take 6 Minute Walk Test (6MWT) [3] , followed by a resting period
of 2 minutes, then measure their central arterial pressure. Repeat the process for 2
more times to collect a total of 3 measurements under the state of light physical
activities.
d. Ask the patients to rest for 5-10 minutes before their final measurement, and
measure their central arterial pressure while they remain in resting state, take 3
measurements in total at an interval of 2 minutes between each measurement.
[1] Yau K K Y, Loke A Y. Effects of diaphragmatic deep breathing exercises
on prehypertensive or hypertensive adults: A literature review[J].
Complementary therapies in clinical practice, 2021, 43: 101315.
[2] Gholamrezaei A, Van Diest I, Aziz Q, et al. Psychophysiological
responses to various slow, deep breathing techniques[J]. Psychophysiology,
2021, 58(2): e13712.
[3] Agarwala P, Salzman S H. Six-minute walk test: clinical role, technique,
coding, and reimbursement[J]. Chest, 2020, 157(3): 603-611.

7. Methods (3/4)
Data Analysis: (1/2)
1. Data preprocessing: Cleaning data to exclude outlier measurements;
2. Statistical analysis:
① Analyzing the consistency of central arterial pressure measurements under the same activity state. For each of
the following activity states, compare the value of the first measurement, the average value of the next two
measurements, and the average value of all three measurements; in addition, calculate the maximum value,
minimum value, mean value, and mean square deviation under each activity state.
a) Resting state prior to any physical activity experiments;
b) Uneven breathing state after 6 deep breaths;
c) Light physical activity state after taking the 6 Minute Walk Test (6MWT);
d) Resting state at the end of all physical activity experiments.
② Analyzing resting state central arterial pressure measurements at the beginning and the end of the experiment,
by comparing the following indicators:
a) Value of the first measurements;
b) Average value of the last two measurements;
c) Average value of all three measurements;

8. Methods (4/4)
Data Analysis: (2/2)
③ Analyzing the central arterial pressure between the resting state at the beginning of the experiment with uneven
breathing state, by comparing the same set of indicators as above in ②.
④ Analyzing the central arterial pressure between the resting state at the beginning of the experiment with light
physical activity state, by comparing the same set of indicators as in ②.
⑤ Analyzing central arterial pressure variability of individual patients under different activity states:
a) Plot a curve to reflect the change in central arterial pressure for each subject undertaking the experiment;
b) Calculate the difference between the maximum value and the minimum value, the mean value and the
mean square deviation;
c) Define the coefficient of variation (CV) of central arterial pressure: Using step-by-step method to calculate
the difference between every two adjacent values, then calculate the coefficient of variation by averaging
the sum of the absolute values of these differences;
d) Compare the resting state central arterial pressure at the beginning of the experiment to that of all other
activity states.
⑥ Other secondary analysis measures: conduct user experience questionnaire with HCPs and patients
undertaking the experiment to evaluate the acceptance and satisfaction of using the SphygmoCor® for
ambulatory central arterial pressure monitoring.

9. Methods
•Research Roadmap
Stage 1: Preparation
Applying for equipment and
ethical approval
3 month
Patients recruitment
and data acquisition
# of patients: 80-100
6 month
Data analysis and
preparation for the
deliverables
3 month
Stage 2: Collecting Data Stage 3: Analysis and Summary
Requested Funding: $80,000
Deliverables:
• To construct a database of non-invasive arterial vascular function changes in hypertensive patients
• To construct a cardiovascular disease risk prediction model based on central arterial pressure
• To publish 1-2 articles and apply for 1-2 patents

10. Relative Groundwork
Fundings:
• Received funding from the Dean's Fund of Anzhen Hospital from 2015 to 2017 for a new management strategy
and effectiveness evaluation of "four-dimensional monitoring" for hypertension in the elderly population.
Publication:
• 匡泽民,唐欣颖,奉淑君,等.无创中心动脉压与靶器官损害研究进展[J].中华高血压杂志 2019(9):4.
• Li Y, Chen X, Zhang Y, et al. Noninvasive continuous blood pressure estimation with peripheral pulse transit
time[C]//2016 IEEE Biomedical Circuits and Systems Conference (BioCAS). IEEE, 2016: 66-69.
• Li Y, Li S, Deng N. Noninvasive and continuous blood pressure monitoring with better accuracy by combining
pulse arrival time and peak delay[J]. International Journal of Distributed Sensor Networks, 2018, 14(12.
• Li Y, Li S, Song H, et al. Noninvasive blood pressure estimation with peak delay of different pulse waves[J].
International Journal of Distributed Sensor Networks, 2019, 15(3.

11. Significance & Contribution
• Increase the frequency of device measurement and promote the clinical value of the device
• Develop new clinical potential service for the hospital by leveraging the superior performance of the device
• Provide more clinical options for the HCP in various patient population
• The role and contribution of equipment in this project
• Accurate acquisition of multiple central arterial pressure
• To provide important basis for evaluating vascular status and clinical diagnosis of related diseases
Future study
• Ambulatory and continuous monitoring of central arterial pressure
• Expansion of clinical scenarios and indications