TiVi Evaluation of Microcirculatory Reactivity of the Skin to Galvanic Stimulation: Effect of Aspirin

Study Overview
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Brief Summary
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Prospective interventional study. The aim is to analyze the effect of usual ongoing treatments over microvascular cutaneous response to galvanic current applications (CIV: current induced vasodilatation) with tissue vitality (TiVi) system on the forearm of subjects referred for ultrasound investigations due to suspicion of peripheral disease. Hypothesis is that the use of aspirin (even at low dose) abolishes the response. This test could make it possible to detect the functional effects of low dose aspirin without using biological tests. A routine clinical application could be to use this CIV to verify adherence to aspirin.

Detailed Description
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At admission eligible patients are proposed to participate. Written consent is signed after complete oral and written explanation of the protocol is signed. No register of non-included patients will be kept. In included patients, in parallel to the routine ultrasound investigation for which the patient is referred, microvascular investigation will be performed as explained later in arm description. Usual ongoing treatments are obtained by history and recorded. The end of the visit is the end of the participation of the subjects.

Official Title
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Performance du TiVi Pour évaluer la réactivité Microcirculatoire de la Peau à l'Application d'un Courant Galvanique, Effet de l'Aspirine

Conditions
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Peripheral Arterial Disease

Intervention / Treatment
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* Device: TiVi system


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: subjects referred for investigation of peripheral arterial disease. Affiliation to the French National healthcare system French speaking patients Ability to stand still for half a minute. Exclusion Criteria: pregnancy inability to understand the study goal Patients protected by decision of law

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: PAD patients<br>Experimental: PAD patients Patients referred for vascular ultrasound investigation for suspicion of peripheral artery disease (PAD). Intervention is measurement of microvascular response to current application on the skin by TiVi system | Device: TiVi system<br>* Device: TiVi system A galvanic current (0.1 mA) will be applied between 2 patches on the forearm of patient and protocol was repeated at 4 minutes. Microvascular response to current application (CIV) will be recorded by TiVi system 10 minutes later. Measurement of the value of skin blood flow (by TiVi system) at the stimulated area as compare to a non stimulated adjacent skin value taken as a reference Usual treatment will be recorded<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Factor associated with CIV amplitude | Determination of the coefficient r² characterizing the quality of the univariate linear regression explaining the Delta2 (maximum differential amplitude of the response to galvanic current between stimulated and non-stimulated zone) by the quantity of aspirin administered (expressed in mg). | 10 minutes after the second period of current application | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Role of aspirin in impaired CIV | Likelihood ratio comparison of the univariate model to a multivariate model including all factors, primarily medicated, that may be associated with impaired CIV in vascular patients | 10 minutes after the second period of current application | 
| Determination of the CIV cut-off value to optimally discriminate patients on aspirin from patients not taking aspirin | Delta2 value (threshold CIV) minimizing distance to 100/100% sensitivity / specificity of receiver operating characteristics (ROC) analysis | 10 minutes after the second period of current application | 
| Survival rate without major cardiovascular event (MACE) in patients with or without aspirin | the event-free survival rate is defined as the time between the inclusion date and the event date. If no event is observed at 24 months | at 12 months and 24 months | 
| Survival rate without major cardiovascular event (MACE)in patients with aspirin according to the CIV response. | the event-free survival rate is defined as the time between the inclusion date and the event date. If no event is observed at 24 months | at 12 months and 24 months. |