Radial Artery Versus Saphenous Vein Patency (RSVP) Study

Study Overview
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Brief Summary
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The purpose of this study is to determine whether the radial artery (artery in the arm) or saphenous vein (vein in the leg), when used as bypass grafts for coronary artery bypass surgery, have a greater patency rate (degree of opening)at 5 years after surgery.

Detailed Description
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Arteries differ from veins both in morphology and physiology. Thus the way they behave as in vivo conduits when used in coronary artery bypass grafting is also likely to be different. This may partly explain the predisposition of veins used as coronary conduits to accelerated atherosclerosis in comparison with the internal mammary artery grafts. There are presently few data describing the properties of the radial artery as an in-vivo coronary conduit over the longer-term. The study will compare angiographic patency of the radial artery or saphenous vein graft anastomosed to the native left circumflex coronary territory at 3 months and 5 years after surgery. A substudy will compare 5-year post-surgery diameter and blood flow of in-vivo radial artery and saphenous vein grafts in response to endothelium-dependent and non-endothelium-dependent stimuli when patients attend for their scheduled follow-up angiogram.

Official Title
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A Randomised Controlled Trial to Compare Angiographic Patency of Radial Artery Versus Saphenous Vein Used as Free Aorto-coronary Grafts in Coronary Revascularization

Conditions
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Coronary Arteriosclerosis

Intervention / Treatment
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* Procedure: Coronary artery bypass graft (CABG) surgery


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: on waiting list for clinically-indicated myocardial revascularization surgery aged 40-70 years significant stenosis (≥70%) in the circumflex territory as identified on preoperative angiograms negative Allen's test (defined as the return of palmar circulation within 5 seconds of releasing ulnar artery compression) willing to give written informed consent Exclusion Criteria: poor left ventricular (LV) function (LV ejection fraction <25%) severe diffuse peripheral vascular disease or bilateral varicose venous disease inability to comply with the angiographic follow-up at 3 months or/and 5 years

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 70 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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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Saphenous vein<br>Saphenous vein aortocoronary bypass graft | Procedure: Coronary artery bypass graft (CABG) surgery<br>* Patients were randomized to receive either a radial artery or a long saphenous vein graft to the left circumflex coronary artery territory during CABG surgery<br>|
| Experimental: Radial artery<br>Radial artery aortocoronary bypass graft | Procedure: Coronary artery bypass graft (CABG) surgery<br>* Patients were randomized to receive either a radial artery or a long saphenous vein graft to the left circumflex coronary artery territory during CABG surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patency Rates | Angiographic patency rates of radial artery and long saphenous vein grafts at follow-up angiography | 5 years | 
| Mean Diameter of the Study Graft (Saphenous Vein or Radial Artery) | Diameter response of the study vessel (saphenous vein or radial artery graft) to acetylcholine, measured using quantitative coronary angiography from the coronary angiogram. | 5 year follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood Flow Volume | Graft flow response to acetylcholine, calculated from vessel diameter using quantitative coronary angiography, and velocity using an intragraft Doppler wire. | 5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Coronary artery bypass, Coronary arteries, Atherosclerosis, Angiography, Blood flow