Current Status and Progress in Arterial Stiffness Evaluation: A Comprehensive Review

doi:10.37015/AUDT.2024.240064

Abstract

Abstract:

Arterial stiffness (AS) represents a pathological process characterized by reduced arterial elasticity and compliance, closely linked to aging and cardiovascular diseases, including hypertension, atherosclerosis, diabetes, and chronic kidney disease. As an important predictor of cardiovascular risk, AS evaluation plays a crucial role in early detection, disease monitoring, and therapeutic guidance. This review aims to systematically summarize current advancements in AS evaluation, focusing on non-invasive techniques such as pulse wave velocity, ultrasound-based methods, and arterial pressure waveform analysis. We discuss the advantages, limitations, and clinical applications of these methods, highlighting the recent integration of artificial intelligence and machine learning to enhance diagnostic accuracy and automation. The review also explores emerging biomarkers and novel imaging techniques, such as shear wave elastography and ultrafast ultrasound imaging, which offer promising insights for early AS detection and risk stratification. Despite significant progress, challenges remain in standardizing measurement protocols and improving sensitivity across various populations. Future research directions emphasize the development of wearable technologies, artificial intelligence-based diagnostic tools, and standardized methodologies to advance AS evaluation and improve cardiovascular outcomes.

Key words: Arterial stiffness; Non-invasive; Echocardiography

Yang Yun, Zhang Xin, Zhang Ruize, Jiang Jingrong, Xie Yuji, Fang Lingyun, Zhang Jing, Xie Mingxing, Wang Jing. Current Status and Progress in Arterial Stiffness Evaluation: A Comprehensive Review. Advanced Ultrasound in Diagnosis and Therapy, 2024, 8(4): 172-182.

Figures/Tables 5

Table 1

Overview of ultrasound techniques in arterial stiffness assessment"

Parameters	Measurement method	Interpretation	Advantages	Disadvantages	Considerations
PWV	Doppler Ultrasound	Higher PWV values (m/s) indicate greater AS and higher cardiovascular risk	Convenient; allow for simultaneous evaluation of cardiac function and AS	Influenced by hemodynamic factors; requires accurate distance measurement; operator-dependent	Standardized operation needed, avoid influences from blood pressure and heart rate fluctuations
IMT	Two-dimensional ultrasound	Thickened IMT indicates atherosclerosis and increased cardiovascular risk	Real-time direct evaluation of arterial structural changes	Depend on image quality and operator experience	Commonly used for carotid artery evaluation
Aortic distensibility	M-mode or two-dimensional ultrasound	Change in aortic diameter during the cardiac cycle Lower distensibility is associated with higher AS and cardiovascular risk	Simple	Easily affected by changes in blood pressure	Standardized operation and measurement needed
Flow-mediated dilation	Brachial artery ultrasound	The ability of the artery to dilate in response to increased blood flow, reflects endothelial function	Non-invasive assessment of endothelial function	Requires precise operation and timing control	Strict adherence to protocols; avoid external interferences
β-stiffness index	M-mode or two-dimensional ultrasound	A higher index indicates higher AS	Assesses local AS; independent of blood pressure	Limited use in large central arteries	Can be influenced by arterial wall thickness and vascular smooth muscle tone
Aortic wall Motion velocity	Tissue Doppler Imaging	The lower the velocity, the greater the AS; local evaluations	Quantitative	Requires specialized training	Operator must have specialized knowledge
Strain and strain rate	Speckle Tracking Echocardiography	The deformation of arterial walls during the cardiac cycle, lower value indicates stiffer arteries	Sensitive to early changes in AS	Require post-processing workstation and specialized knowledge; high demands on image quality	Image quality and frame rate should be considered to ensure accurate results
Ultrafast ultrasound imaging	Ultra-high frame rate ultrasound technology	Real-time assessment of local AS; assess cardiac function, blood flow, and myocardial strain with	Real-time; higher precision and temporal resolution	The high cost and complexity limit its widespread use in routine clinical practice; require specialized training	Regular calibration needed to ensure measurement accuracy
Shear wave elastography	Generate shear waves in tissue and measure their propagation speed	Measure local tissue stiffness; higher value indicates greater stiffness	Applicable to local arteries or small areas; independent of blood pressure	Limited to specialized centers with advanced equipment, and operator training is needed
Ultrasound time harmonic elastography	Harmonic vibrations generate time harmonic frequencies	Evaluation of overall AS. Higher value indicates greater AS	Suitable for overall stiffness of large arteries, especially for chronic disease and research	Requires specialized equipment and expertise, and the imaging time is long

Table 1

Table 2

Figure 1

Table 3

Parameters for arterial stiffness evaluation using pressure and waveform analysis-based techniques"

Parameters	Measurement method	Interpretation	Advantages	Disadvantages	Considerations
PWV	Pressure sensors	The higher the PWV, the greater the AS	The "gold standard"	Requires specialized equipment, relies on operator experience.	1. Environmental factors: Measurements should be taken in a quiet environment with suitable temperature.
CAVI	Simultaneously measures electrocardiogram, phonocardiogram, and limb blood pressure.	A higher CAVI indicates greater AS	Stable with minimal influence from blood pressure	Certain requirements for the equipment and environment.	2. Equipment calibration: Equipment should be regularly calibrated and maintained.
ABI	Ankle Systolic Pressure / Brachial Systolic Pressure	ABI < 0.9 indicates peripheral artery disease, > 1.4 indicates vascular calcification	Simple, quick, effective for screening peripheral artery disease	Affected by vascular calcification, which may lead to false normal or elevated results	3. Patient's physiological state: Strenuous exercise, emotional agitation, and intake of coffee or tea before the examination should be avoided.
AIx	Pulse waveform analysis	A higher index indicates greater AS and increased central arterial pressure	Can assess central arterial pressure	Affected by factors such as heart rate, age, and height	5. Consider the effects of medications.
Characteristic impedance	Analysis of Aortic Pressure and Flow Waveforms	The higher value indicates the greater the AS	Reflects the instantaneous mechanical properties of the arteries	Complex; requires specialized equipment and trained personnel	6. Repeat measurements to obtain an average value.
Effective arterial elastance	End-systolic pressure/ stroke volume (mmHg/mL)	Higher values indicate increased AS and greater demands on cardiac function	Evaluates ventricular-arterial coupling	Requires invasive measurements or estimations, and the calculations are complex	7. Need to combine with clinical context.

Table 3

Figure 2

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Parameters	Measurement method	Interpretation	Advantages	Disadvantages	Considerations
PWV	Ultrasound	Used in clinical research to reflect AS in different locations	Evaluate regional AS; integration with functional imaging	Depends on measurement sites; operator dependence	Mainly used for research purposes, with fewer clinical applications nowadays
cfPWV	Pressure sensors	Reflects the stiffness of large arteries	Gold standard	Dependent on equipment and environmental factors	Repeated measurement; Regular calibration; Standardized measurement paths and calculation methods; quiet environment; Consider Patient's physiological state and medications
Brachial-ankle PWV (baPWV)	Pressure sensors	Reflects the arterial stiffness of the limbs	Suitable for large-scale clinical screening	Does not fully represent the stiffness of central arteries
SphygmoCor	Pressure sensors	Widely used non-invasive measurement of AS	Considered the gold standard for measuring cfPWV	High cost; operator training is required
Complior	Piezoelectric sensor measurement	Widely used non-invasive measurement of AS	Provides reliable and repeatable measurements of PWV	High cost; operator training is required