Coronary Arteriosclerosis
Conditions
Keywords
Coronary artery bypass, Coronary arteries, Atherosclerosis, Angiography, Blood flow
Brief summary
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
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.
Interventions
PROCEDURECoronary artery bypass graft (CABG) surgery
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
Sponsors
The Royal College of Surgeons of England
Royal Brompton & Harefield NHS Foundation Trust
National Heart Foundation, Australia
Victor Phillip Dahdaleh Charitable Foundation
Imperial College London
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
40 Years to 70 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Patency Rates | 5 years | Angiographic patency rates of radial artery and long saphenous vein grafts at follow-up angiography |
| Mean Diameter of the Study Graft (Saphenous Vein or Radial Artery) | 5 year follow-up | Diameter response of the study vessel (saphenous vein or radial artery graft) to acetylcholine, measured using quantitative coronary angiography from the coronary angiogram. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Blood Flow Volume | 5 years | Graft flow response to acetylcholine, calculated from vessel diameter using quantitative coronary angiography, and velocity using an intragraft Doppler wire. |
Countries
United Kingdom
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Saphenous Vein Saphenous vein aortocoronary bypass graft
Patients were randomized to receive a long saphenous vein graft to the left circumflex coronary artery territory during CABG surgery | 60 |
| Radial Artery Radial artery aortocoronary bypass graft
Patients were randomized to receive a radial artery graft to the left circumflex coronary artery territory during CABG surgery | 82 |
| Total | 142 |
Baseline characteristics
| Characteristic | Saphenous Vein | Radial Artery | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 19 Participants | 14 Participants | 33 Participants |
| Age, Categorical Between 18 and 65 years | 41 Participants | 68 Participants | 109 Participants |
| Race and Ethnicity Not Collected | — | — | 0 Participants |
| Sex: Female, Male Female | 2 Participants | 3 Participants | 5 Participants |
| Sex: Female, Male Male | 58 Participants | 79 Participants | 137 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 4 / 60 | 3 / 82 |
| other Total, other adverse events | 0 / 60 | 0 / 82 |
| serious Total, serious adverse events | 11 / 60 | 13 / 82 |
Outcome results
Primary
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.
Time frame: 5 year follow-up
Population: Intracoronary physiology investigations (diameter and intracoronary Doppler blood flow velocity measurements) were carried out in a subgroup of patients (n=27).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Saphenous Vein | Mean Diameter of the Study Graft (Saphenous Vein or Radial Artery) | 3.18 mm | Standard Deviation 0.67 |
| Radial Artery | Mean Diameter of the Study Graft (Saphenous Vein or Radial Artery) | 2.7 mm | Standard Deviation 0.29 |
Primary
Patency Rates
Angiographic patency rates of radial artery and long saphenous vein grafts at follow-up angiography
Time frame: 5 years
Population: 103 of the patients randomized at the time of surgery agreed to return for the 5-year follow-up angiogram.
| Arm | Measure | Category | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Saphenous Vein | Patency Rates | Patent graft | 38 Participants |
| Saphenous Vein | Patency Rates | Occluded graft | 6 Participants |
| Radial Artery | Patency Rates | Patent graft | 58 Participants |
| Radial Artery | Patency Rates | Occluded graft | 1 Participants |
Secondary
Blood Flow Volume
Graft flow response to acetylcholine, calculated from vessel diameter using quantitative coronary angiography, and velocity using an intragraft Doppler wire.
Time frame: 5 years
Population: 27 of the patients who returned for the 5 year angiogram were eligible for invasive measurement of blood flow.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Saphenous Vein | Blood Flow Volume | 39 ml/min | Standard Deviation 15 |
| Radial Artery | Blood Flow Volume | 44 ml/min | Standard Deviation 19 |