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.
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.
Study Type
OBSERVATIONAL
Enrollment
195
The Iowa Clinic
Des Moines, Iowa, United States
Mercy Research
Chesterfield, Missouri, United States
The Mt. Sinai Hospital
New York, New York, United States
Ohio Health
Columbus, Ohio, United States
Sensitivity and Specificity of FlowMet-R for Diagnosis of PAD and CLI
Primary objective is to determine the efficacy of FlowMet-R measurements in diagnosing PAD \& CLI. All patients were combined from healthy \& PAD groups to form one cohort, ABI and TBI were then used to assign patients in PAD (1), PAD (2) \& CLI. FlowMet-R data (comprised of blood flow measurements and/or feature analysis of the blood flow waveform) were used to create a predictive model of PAD severity. This model was used to generate diagnostic receiver operating characteristic (ROC) curves for PAD and, independently, CLI, at three time points. ROC curves were used to compute the peak sensitivity, peak specificity, and area under the curve (AUC) at the initial, 3-month and 6-month time points. Sensitivity, specificity and AUC are unitless. Sensitivity is the percentage of true positives \& specificity is the percentage of true negatives at the location on the ROC curve where it was closest to the upper left of the unit square from an ROC curve (peak).
Time frame: Initial, three month, and six month time points.
Sensitivity and Specificity of FlowMet-R for Prognosis of Requiring a Peripheral Vascular Intervention
ROC curves for predicting if a patient will undergo intervention following their initial visit were generated using FlowMet-R measurement data. ROC curves were used to compute the peak sensitivity, peak specificity, and area under the curve (AUC) within the 3-month and 6-month time points, separately. Sensitivity, specificity and AUC are unitless. Sensitivity is the percentage of true positives \& specificity is the percentage of true negatives at the location on the ROC curve where it was closest to the upper left of the unit square from an ROC curve (peak).
Time frame: Within three and six months following initial visit
Sensitivity, Specificity and Area Under the Curve (AUC) 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) at the initial visit. Sensitivity, specificity and AUC are unitless. Sensitivity is the percentage of true positives \& specificity is the percentage of true negatives at the location on the ROC curve where it was closest to the upper left of the unit square from an ROC curve (peak).
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Ascension Seton
Austin, Texas, United States
Time frame: Initial visit
Stenosis Percentage
A correlation test will be performed between FlowMet-R and stenosis percentage. The correlations between the acceleration time from the FlowMet-R device and peripheral artery stenosis will be computed using a Pearson correlation. Correlation will be computed using available FlowMet-R data from PAD participants with significant stenosis, defined by greater than 50%, in at least one peripheral artery at the initial visit.
Time frame: Initial visit
Changes in Ankle Brachial Index (ABI)
The outcome ABI is a ratio of blood pressures in the arm and ankle. Values less than 1 generally indicate narrower arteries. The outcome used the change in ABI for: 0 to 3 months, 0 to 6 months, and 3 to 6 months. The correlation with this outcome was estimated using the corresponding change in acceleration time from the FlowMet-R device.
Time frame: Within three and six months following initial visit.
Changes in Toe Brachial Index (TBI)
The outcome TBI is a ratio of blood pressures in the arm and toe. Values less than 1 generally indicate narrower arteries. The outcome used the change in TBI for: 0 to 3 months, 0 to 6 months, and 3 to 6 months. The correlation with this outcome was estimated using the corresponding change in acceleration time from the FlowMet-R device.
Time frame: Within three and six months following initial visit.
Changes in Rutherford Classification
Rutherford Classification is an ordinal scale that ranges from 0 to 6 and is used to measure peripheral arterial disease severity and chronic limb threatening ischemia. Higher values indicate more severe disease. The changes for Rutherford Classification were computed for: 0 to 3 months, 0 to 6 months, and 3 to 6 months. The correlation with this outcome was estimated using the corresponding change in acceleration time from the FlowMet-R device.
Time frame: Within three and six months following initial visit.