Scientific Backgrounds, Lectures & Methodology

1. Why Do We Have to Measure Arterial Stiffness?

Here you can learn more about the scientifically proven correlation between arterial stiffness and cardiovascular risk.  

Due to ageing and vascular calcification the arteries become stiffer and stiffer. The stiffened aortic wall impairs the reservoir (Windkessel) function of the aorta and leads to increased cardiovascular morbidity and mortality. The increased aortic stiffness, measured as aortic pulse wave velocity (PWVao) is an independent predictor of major cardiovascular events. The measurement of aortic stiffness (PWVao) provides information about the cardiovascular risk even in those cases, when other known risk factors do not refer to CV risk, because the patient is young, the blood pressure, cholesterol, glucose are in normal range, the patient is non-smoker and has no increased body mass index (BMI).

2. Parameters Used to Describe Arterial Function (Stiffness)

This section clarifies the concepts of Aortic Pulse Wave Velocity (PWVao), Augmentation Index (AIx), Central Systolic Blood Pressure (SBP) and Pulse Pressure (PP).

The aortic PWV refers to the characteristics of the aortic wall; the stiffer the wall, the higher the PWVao. The aortic AIx primarily related to the actual peripheral vascular (arteriolar) resistance. The high the value of aortic AIX, the higher the resistance (tone) of the small arteries and arterioles. The central SBP and PP are related to the systemic BP and also to the AIx. The values of central SBP and PP are physiologically lower than measured peripherally.

3. Endothelial Dysfunction and Its Relation to Augmentation Index (AIx)

It is explained how Augmentation Index (AIx) is a marker of the arterial tone/resistance.

Endothelial dysfunction is known as the impairment of the endothelial-dependent vasodilatation. Endothelial dysfunction always goes together with vasoconstriction and increased peripheral arteriolar resistance. AIx is mainly influenced by the energy (amplitude) of the reflected systolic wave. Increased vascular resistance causes increased reflected wave amplitude and increased AIx. Consequently by measuring AIx the endothelial dysfunction caused increased vascular resistance can be detected.

4. Limitations of the Formerly Used Methods Measuring Arterial Stiffness

Learn more about the drawbacks of most frequently applied non-invasive methods.

The formerly used methods (applanation tonometry and piezoelectric methods) required trained personnel and skill to perform the measurement. Thus their implementation to the daily, routine clinical work was considerably limited. During the applanation (decreasing the diameter of the artery) Bernoulli effect will take part causing difficulties in perceiving the second, reflected systolic wave. The aortic PWV is widely accepted predictor of MACE. During carotid-femoral measurement of PWV not only the aorta, but other arteries (carotid, iliac, femoral) are also involved in the measurement of PWV, however the PWV in these arteries are different (higher) physiologically than the aortic PWV.

5. The Arteriograph

Why Arteriograph is the #1 solution to simply measure arterial stiffness? Find the answer here and get a basic understanding of atherosclerosis.

Arteriograph is the first, validated oscillometric method to measure peripheral and central blood pressure, aortic augmentation index and aortic pulse wave velocity simultaneously. 100+ independent scientific papers prove its utility in different clinical conditions. The Arteriograph measurement is user independent, takes only 2 minutes. It has the best variance (repeatability) and reproducibility compared to applanation tonoletric and piezoelectric method.

6. Arteriograph as a Useful Method to Screen for Sub-clinical Carotid Atherosclerosis

Atherosclerosis is commonly described as "the silent killer." Understand why Arteriograph is the solution for early screening and detection.

In a large cohort (643), Arteriograph measured aortic PWV >9.3 m/s showed 76.5% sensitivity, 64.5% specificity, 68.0% PPV, 73.6% NPV, 2.6 RR and 6.0 OR to reveal carotid atherosclerosis (plaques). Based on these results if the Arteriograph measured aortic PWV exceeds this level, carotid ultrasound scan is suggested.

7. Validations

Arteriograph has been validated against invasively measured counterparts regarding multiple parameters. Further details are shared in this section.

As a result of validation, Augmentation Index (AIxao), Central Blood Pressure (SBPao) and Pulse Wave Velocity (PWVao) showed strong correlation with the invasively obtained values. The observed limits of agreement are encouragingly low for accepting the method for clinical use. PWVao values measured by Arteriograph, are close to the true aortic PWV determined invasively.

8. Medical Areas Where the Value of the Measurement of the Arterial Function (Stiffness) Has Been Proven

The Arteriograph has proven clinical value in the following medical areas; cardiology, nephrology, hypertension, diabetes, obstetrics, gynaecology, paediatrics, anaesthesiology, sport medicine, and scientific researches.