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

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

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

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.

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.

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 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

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).

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

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

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

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

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

Ramondou P, Hersant J, Fouquet O, Sempore WY, Abraham P, Henni S. Current-Induced Vasodilation Specifically Detects, and Correlates With the Time Since, Last Aspirin Intake: An Interventional Study of 830 Patients. J Cardiovasc Pharmacol Ther. 2021 May;26(3):269-278. doi: 10.1177/1074248420971165. Epub 2020 Nov 7.