New Oxymetry Indices in Critical Limb Ischemia

Study Overview
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Brief Summary
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Transcutaneous oxygen tension (TcpO2) at rest, sensitized by oxygen inhalation tests, is widely applied for the evaluation of chronic critical limb ischemia (CLI). If foot TcpO2 measurements are good prognostic factors of the risk of amputation or the probability of wound healing without amputation, they have never proven their hability to estimate the risk of death in patients with critical limb ischemia. On the one hand, studies have considered only the response observed on legs without considered the thoracic variations. On the other hand, the variability of the TcpO2 signal has never been analyzed as a prognostic factor. The objective of the NOVICE study is therefore to assess, first, whether the variability of resting TcPO2 values at thoracic probe as well as at affected limb probe is a morbidity-mortality prognostic factor and secondly, to evaluate during the oxygen tests, if the measurement of the amplitude of the distal responses in ischemic zone compared to the response observed in thoracic probe is a prognostic factor of morbi-mortality.

Detailed Description
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This is an ambispective (both retrospective and prospective) cohort study in which any major patient, referred for resting (transcutyaneous oxygen pressure = TcpO2) for suspicion of critical limb ischemia, is included retrospectively and prospectively from November 2018 to October 2020. Tcpo2 recording are analysed to determine specific parameters (signal variability and response top oxygen). A morbidity-mortality follow-up is carried out between 12 and 15 months after the Tcpo2 measurement. A Kaplan Mayer study of these indices against MALE (major adverse lower limb events ) and MACE(Major adverse cardiovascular events) will be carried out.

Official Title
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New Oxymetry Indices in Critical Limb Ischemia (French Original Title is Nouveaux Indices Oxymétriques Chez Les Patients Vus Pour Suspicion d'Ischémie Critique du membrE inférieur)

Conditions
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Critical Limb Ischemia

Intervention / Treatment
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* Diagnostic Test: transcutaneous oximetry


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Suspicion of Critical limb ischemia Reffered for Tcpo2 Absence of rebuttal to the use of the data by the patients Exclusion Criteria: No available tcpo2 recording Rejection of the follow up by the patients

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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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: transcutaneous oximetry|Analysis of transcutaneous oximetry (Tcpo2) in terme of variability at rest and of response to oxygen inhalation|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mortality | presence of MACE (major adverse cardiovascular event) following the oximetry test | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Morbidity | presence of MALE (major adverse lower limb event) following the oximetry test | 12 moths | 
| Mortality (intermediate analysis) | Mortality all causes (intermediate analysis prior to Covid interference) | 6 months minimal follow-up | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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oxygen, peripheral artery disease, follow-up, transcutaneous oximetry