Outcomes in Femoropopliteal Disease Stratified by Translesional Pressure Gradient

Study Overview
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Brief Summary
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To perform an observational analysis to determine if mean translesional gradient measurements (TLG) are associated with differences in clinical outcomes in patients with femoropopliteal arterial disease and claudication. Hypothesis: Patients stratified by a residual translesional gradient </= 11 mmHg after peripheral revascularization or angiography alone will have better clinical outcomes than patients with TLG > 11 mmHg as assessed by six minute walk (6MW), walking impairment questionnaire scores (WIQ), ankle brachial index and need for repeat procedure at 6 months.

Detailed Description
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The role of measuring translesional pressure gradients(TLG) in peripheral arterial disease lesions below the iliac artery is unclear. In a previous study the investigators demonstrated that a pressure wire can be effectively used to measure gradients in the femoropopliteal (FP) arterial bed showing good correlation between TLGs recorded with exercise ankle brachial index and walking impairment scores. However there is a no evidence that effectively modifying the gradient or having a high residual gradient after revascularization or just with medical therapy correlates with worse clinical outcomes. This is a prospective, single center, observational clinical study to evaluate whether measurement of mean residual TLG at the time of angiography and/or immediately after endovascular revascularization are associated with clinically important outcomes in patients with claudication symptoms. Prior to angiography they will be asked to complete an ankle brachial index evaluation, baseline six minute walk test and walking impairment questionnaire. Arterial access should be obtained in the contralateral common femoral artery to the symptomatic limb if feasible. Angiographic images are to be obtained, interpreted and clinical decisions regarding endovascular treatment are to be made per treating physician's discretion prior to obtaining translesional pressure gradients. In patients whose angiogram does not meet exclusion criteria and do not have a chronic total occlusion (CTO) a baseline TLG will be obtained. A 0.014 pressure wire/catheter to measure pressure will be inserted. After baseline calibration in the superficial femoral artery, the wire will be inserted past the narrowest lesion into the popliteal vessel. Intra-arterial adenosine 100-200 mcg will be given for hyperemia and measurements are to be recorded. If an intervention is planned, repeat measurements are to be obtained at the end of the procedure. If no intervention is planned this will be the residual or final TLG recorded. If baseline measurement are unable to obtained due to a CTO then only a post intervention residual TLG will be obtained and included in analysis. The operator will be blinded to the pre and post TLG measurements by turning the display monitor away from the procedure table and towards the recorder situated in the procedure room when measurements are being obtained. Patients will follow up within two weeks post angiography for routine scheduled follow up and will obtain repeat ABI, WIQ, and six minute walk if they underwent revascularization. Treating physicians and study coordinators collecting these test measurements will be blinded to TLG measurements but not to angiography and treatment. Patients will again be evaluated at 6 months follow up with repeat ABI, WIQ and six minute walk.

Official Title
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Outcomes in Femoropopliteal Disease Stratified by Translesional Pressure Gradient

Conditions
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Peripheral Arterial Disease, Claudication

Intervention / Treatment
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* Procedure: translesional gradient measurement


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Signed informed consent At least 18 years old Unilateral lower limb claudication Rutherford class 2-4 Subjects must be able to complete screening six minute walk, walking impairment questionnaire, and baseline ankle brachial index Estimated survival ≥1 year in the judgment of the primary operator Documented symptomatic femoropopliteal (FP) atherosclerotic disease with at least moderate angiographic stenosis in the symptomatic lower extremity Subjects with multilevel disease can be screened and enrolled after treatment of other non FP PAD Exclusion Criteria: Life expectancy less than 12 months or other medical co-morbid condition(s) that could limit the subject's ability to participate in the trial, limit the subject's compliance with the follow-up requirements, or impact the scientific integrity of the trial Severe Bilateral claudication Known hypersensitivity or contraindication to contrast dye that, in the opinion of the investigator, cannot be adequately pre-medicated Known hypersensitivity to adenosine or moderate to severe asthma Pregnancy Serum Creatinine >2.5 Vascular graft, aneurysm or postsurgical stenosis of the target vessel Documented untreated severe iliac or below-the knee stenosis with < 2 vessel run-off in leg with femoropopliteal stenosis or untreated bilateral symptomatic peripheral arterial disease

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

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| final TLG </=11 mmHg<br>includes all patients who have a final mean translesional gradient measurement (TLG) < 11 mmHg regardless if revascularization is done or not. | Procedure: translesional gradient measurement<br>* Patients will be stratified into two groups based on the final mean translesional pressure gradient obtained in the femoropopliteal arterial bed after revascularization or just after angiography if no revascularization is done.<br>|
| final TLG > 11 mmHg<br>includes all patients who have a final mean translesional gradient measurement (TLG) > 11 mmHg regardless if revascularization is done or not. | Procedure: translesional gradient measurement<br>* Patients will be stratified into two groups based on the final mean translesional pressure gradient obtained in the femoropopliteal arterial bed after revascularization or just after angiography if no revascularization is done.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in six minute walk distance in meters at 6 months | Compare change in six minute walk distance at 2 weeks post angiography +/- revascularization to distance walked at 6 months +/- 15 days between patients stratified by a residual mean translesional gradient > 11 mmHg or </= 11 mmHg. The six minute walk test involves walking in a straight 100m hallway back and forth for as far as possible during a six minute time span. | 6 months +/- 15 days after enrollment | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change Walking Impairment Questionairre (WIQ)Score at 6 months | Compare change in WIQ scores from within 2 weeks post angiography +/- revascularization to WIQ score at 6 months +/- 15 days between patients stratified by a residual mean translesional gradient > 11 mmHg or </= 11 mmHg . The walking impairment score used is based on the patient completing short questionnaire about perceived degree of walking impairment at various distances. | 6 months +/- 15 days after enrollment | 
| Change in Ankle Brachial Index (ABI) at 6 months | Change in ABI between patients stratified by a residual mean translesional gradient > 11 mmHg or </= 11 mmHg from the index within 2 weeks post TLG measurement to index at 6 months after measurement | 6months +/- 15 days after enrollment | 
| Change in six minute walk distance from baseline to within 2 weeks post revascularization | Change in six minute walk from baseline measurement in those patients that undergo revascularization to six minute walk distance checked within 2 weeks after revascularization. | baseline pre revascularization to two weeks post measurement | 
| Change in WIQ score from baseline to within 2 weeks post revascularization | Change in WIQ score from baseline measurement in those patients that undergo revascularization to six minute walk distance checked within 2 weeks after revascularization. | baseline pre revascularization to two weeks post measurement | 
| Need for repeat revascularization or amputation as assessed by rates of need in repeat revascularization or amputation | compare rates of need in repeat revascularization or amputation between patients stratified by a residual mean translesional gradient > 11 mmHg or </= 11 mmHg during 6 month period after TLG measurement. | six months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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peripheral arterial disease, claudication, translesional pressure gradient, pressure wire, six minute walk, superficial femoral artery, pressure gradient, endovascular