Validation of Laser Doppler Vibrometer (LDV) for Measurement of Arterial Stiffness in Hypertensive Patients
Condition: Hypertension
MeSH terms: Hypertension
Study type: Interventional

Summary: 
      The aim is to compare a new technique for assessing local and regional arterial stiffness:
      the Laser Doppler Vibrometry with the reference techniques, the applanation tonometry and
      echotracking.
    

Detailed description: 
      Cardiovascular (CV) diseases and their risk factors are the major contributors to global
      morbidity and mortality. CV diseases are responsible for over 17.3 million deaths per year
      worldwide, representing 30% of all global deaths. The measurement of arterial stiffness
      during the medical investigation of a hypertensive subject is essential to estimate the
      overall CV risk. The European Society of Hypertension (ESH) and the European Society of
      Cardiology (ESC) working group recommend its use for CV risk assessment. Indeed, arterial
      stiffness is currently the subject of a scientific consensus due to the large number of
      pathophysiological, epidemiological and pharmacological studies demonstrating that it
      integrates the duration and the level of exposure of the patient to known and identified CV
      risk factors (hypertension, tobacco, diabetes...) as well as those still discussed or more
      difficult to quantify (low birth weight, inflammation, infection, genetics...).

      Arterial stiffness can be assessed in a number of ways, but the non-invasive measurement of
      the carotid-femoral pulse wave velocity (cfPWV) by applanation tonometry is regarded as the
      current gold standard because it corresponds to the aortic stiffness and it has been widely
      validated in epidemiological studies. However, the routine measurement of PWV by applanation
      tonometry is technically demanding and uncomfortable for the patient because the sensors can
      be attached around the neck or involve a palpation of the groin. The more advanced devices
      for PWV assessment are bulky, require trained operators due to the complexity of the
      procedure, and are relatively expensive. Therefore, none of the devices available for
      measurement of PWV are suitable for use in primary care. Measurement of arterial stiffness at
      primary care would allow large population screening for CV risks and thus enable more
      accurate CV risk prediction to better target preventive therapy among those individuals
      considered to be at low or moderate risk according to current guidelines. However, the tools
      and devices available today do not allow for mobile, low-cost, reliable, fast and non- or
      minimally-invasive point-of-care screening for measurement of arterial stiffness.

      PWV measurement by laser Doppler vibrometry, contactless, is more comfortable, acceptable and
      could thus be a substitute for applanation tonometry.

      A laser Doppler vibrometer (LDV) is an instrument that is used to make non-contact vibration
      measurements of a surface. The laser beam from the LDV is directed at the surface of interest
      (in our case the skin covering the artery or the heart), and the vibration amplitude and
      frequency are extracted from the Doppler shift of the reflected laser beam frequency due to
      the motion of the surface. Preliminary data suggest that LDV can lead to an improved
      screening and assessment of CV risk as a technique that makes it possible to measure aortic
      and local PWV. Indeed, Ghent University has successfully demonstrated that aortic PWV can be
      correctly measured with LDV. This method will greatly simplify procedures for measuring
      aortic stiffness if it is available in a compact form and adapted to clinical practice. This
      is the purpose of the CARDIS project, H2020 (http://www.cardis-h2020.eu/), which aims to
      develop a compact device for measuring local and segmental arterial stiffness without contact
      to the skin thanks to the LDV technique. The objective of this study is to compare the CARDIS
      LDV prototype with the reference techniques, carotid-femoral and local carotid PWV.
    

Intervention name(s): PWV measurement by LDV
Intervention type(s): Device
Intervention description(s): PWV measurement by LDV : carotid-femoral, carotid and chest-carotid
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: arterial stiffness; pulse wave velocity; laser Doppler vibrometry