FlowMet-R Blood Flow Measurement for the Diagnosis of Peripheral Artery Disease and Critical Limb Ischemia

Study Overview
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Brief Summary
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Non-randomized, multi-center, longitudinal study of healthy subjects and subjects with PAD who are scheduled for ABI, TBI, and either Duplex Ultrasound or Angiographic assessments in a vascular clinic.

Detailed Description
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Patients scheduled for peripheral vascular examination and healthy controls will be measured with the FlowMet-R, a noninvasive blood flow monitor, and compared to gold standard diagnostics - ABI, TBI, and Doppler Ultrasound. Sensitivity and specificity of the FlowMet-R device output in diagnosing PAD and CLI will be assessed on initial visit, 3-month followup, and 6-month followup.

Official Title
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FlowMet-R Blood Flow Measurement for the Diagnosis of Peripheral Artery Disease (PAD) and Critical Limb Ischemia (CLI)

Conditions
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Peripheral Artery Disease

Intervention / Treatment
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* Diagnostic Test: FlowMet-R
* Diagnostic Test: ABI
* Diagnostic Test: TBI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: PAD Positive Cohort Subject meets PAD positive criteria Subject is willing and able to provide informed consent Subject is willing and able to comply with study procedures Subject is willing and able to understand the study procedures Subject is scheduled for vascular examination that includes noninvasive assessments as standard of care: ABI, TBI, and either a Duplex Ultrasound or Angiogram Healthy Cohort Subject is willing and able to provide informed consent. Subject is willing and able to comply with the study procedures. Subject is able to understand the study procedures. Subject has no history of positive PAD diagnosis, and is not currently suspected of having PAD. Exclusion Criteria: PAD Positive Cohort Subject is under 40 or unable to consent. Subject has any medical condition, which, in the judgment of the Investigator and/or designee, makes the subject a poor candidate for the investigational study. Subject is excluded from analysis if no stenosis is found during Doppler but Tibial disease is suspected and Tibial ultrasound is not able to be performed. Subject does not have a suitable finger to attach the FlowMet-R probe. Subject does not have a suitable 1st or 2nd digit to attach FlowMet-R probe on the limb of interest. Subject has undergone revascularization within the last 90 days Subject cannot lay safely in a supine position. Healthy Cohort Subject is under 40 or unable to consent. Subject has any medical condition, which, in the judgment of the Investigator and/or designee, makes the subject a poor candidate for the investigational study. One or more limbs has a prior or current diagnosis of PAD, or is reasonably suspected of having a diagnosis of PAD. Subject does not have a suitable finger to attach the FlowMet-R probe. Subject does not have a suitable 1st or 2nd digit to attach FlowMet-R probe. Subject has undergone revascularization within the last 90 days

Ages Eligible for Study
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Minimum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy<br>Healthy cohort is an age-matched population (over 40 years old) without history of PAD or suspected PAD. Healthy cohort will receive FlowMet-R measurement, Ankle Brachial Index (ABI), and Toe Brachial Index (TBI) measurements. | Diagnostic Test: FlowMet-R<br>* FlowMet-R is a noninvasive blood flow measurement.<br>Diagnostic Test: ABI<br>* Ankle Brachial Index is a ratio-metric blood pressure measurement in the ankle and arm.<br>Diagnostic Test: TBI<br>* Ankle Brachial Index is a ratio-metric blood pressure measurement in the toe and arm.<br>|
| PAD<br>PAD cohort is all-comers to the vascular lab that are scheduled to undergo assessment for Peripheral Artery Disease (PAD) or have a planned endovascular or surgical intervention to address PAD. PAD cohort patients will receive FlowMet-R measurement in addition to their routine standard of care. | Diagnostic Test: FlowMet-R<br>* FlowMet-R is a noninvasive blood flow measurement.<br>Diagnostic Test: ABI<br>* Ankle Brachial Index is a ratio-metric blood pressure measurement in the ankle and arm.<br>Diagnostic Test: TBI<br>* Ankle Brachial Index is a ratio-metric blood pressure measurement in the toe and arm.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitivity and specificity of FlowMet-R for diagnosis of PAD and CLI | Receiver operating characteristic (ROC) curves for the diagnosis of PAD and, independently, CLI, will be generated using FlowMet-R measurement data. ROC curves will be used to compute the peak sensitivity, peak specificity, and area under the curve (AUC). | Initial, three month, and six month time points. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitivity and specificity of FlowMet-R for prognosis of requiring a peripheral vascular intervention | ROC curves for predicting a patient will undergo intervention following their initial visit will be generated using FlowMet-R measurement data. ROC curves will be used to compute the peak sensitivity, peak specificity, and area under the curve (AUC). | Within three and six months following initial visit | 
| Sensitivity and specificity of FlowMet-R in diagnosing significant stenosis | ROC curves for predicting a patient has significant stenosis, defined by greater than 50%, in at least one peripheral artery will be generated using FlowMet-R measurement data. ROC curves will be used to compute the peak sensitivity, peak specificity, and area under the curve (AUC). | Initial visit | 
| Correlation between FlowMet-R measurements and stenosis percentage | A correlation test will be performed between FlowMet-R and stenosis percentage | Initial visit | 
| Correlation between changes in FlowMet-R measurement and changes in standard diagnostics | A correlation test will be performed between changes in FlowMet-R measurement and changes in standard diagnostics between visits. | Within three and six months following initial visit. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Peripheral Artery Disease, Claudication, Critical Limb Ischemia