Coronary Artery Disease
Conditions
Keywords
Coronary Bypass Surgery, Coronary Artery Disease, Angiography, Arterial Grafts, Radial Artery, Saphenous Vein
Brief summary
Bypass surgery is often required to treat severe coronary heart disease. Either arteries or veins can be used as bypass grafts. We wish to compare the long-term durability of the saphenous vein from the leg to that of the radial artery from the fore-arm when used as bypass grafts. We are examining how many of these grafts are still functioning beyond 5 years after bypass surgery by performing a coronary angiogram. After 1-year, we found that radial arteries were more likely to be functioning than saphenous veins. We hypothesize that radial arteries will continue to be superior beyond 5 years.
Detailed description
The multi-centre Radial Artery Patency Study, (RAPS) is a series of longitudinal graft patency studies designed to compare the long-term patency of the radial artery to the saphenous vein. Between 1996 and 2001, 561 patients were intraoperatively randomized to undergo surgery according to one of two strategies: radial-artery grafting to the circumflex territory and saphenous-vein grafting to the right coronary artery or radial-artery grafting to the right coronary artery and saphenous-vein grafting to the circumflex territory. The first study compared the 8-12 month angiographic patency of the radial artery with that of the saphenous vein as a conduit for coronary artery bypass and found that radial arteries were superior. The primary objective of this current study is to determine the beyond 5-year angiographic patency of the radial artery compared with a saphenous vein coronary bypass graft. HYPOTHESES 1. The angiographic patency of radial artery grafts studied beyond 5 years following surgery exceeds that of saphenous vein grafts. 2. Radial artery conduits studied beyond 5 years postoperatively have less graft disease than saphenous veins. SAMPLE SIZE We expect to study 350 patients, which will allow us to test for a 35% risk reduction from 23% occlusion rate in saphenous veins to 15% in radial arteries, assuming a 5% within-patient correlation, with 80% power for a 2-tailed alpha of 0.05.
Interventions
PROCEDURERadial Artery and Saphenous Vein Grafts Randomized to either right coronary or left circumflex coronary artery territories
Each patient will receive both study grafts (Radial artery and Study Saphenous vein graft). The within-patient randomization scheme will dictate whether the radial goes to the right or circumflex territory. The saphenous vein graft will go to the opposing territory.
Sponsors
Canadian Institutes of Health Research (CIHR)
Sunnybrook Health Sciences Centre
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
30 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
The patient population consists of patients who were enroled into the original Multicentre Radial Artery Patency Study between November 1996 and January 2001. These included patients undergoing isolated coronary artery bypass surgery less than 80 years of age with 3 vessel coronary disease and left ventricular ejection fraction greater than 35%.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The primary endpoint will be the proportion of grafts which are functionally occluded (TIMI flow 0, 1, or 2). | Beyond 5 years after bypass urgery |
Secondary
| Measure | Time frame |
|---|---|
| a) the proportion of occluded study grafts (TIMI 0) | Beyond 5 years after bypass urgery |
| b) the proportion of functionally occluded grafts where proximal stenosis of native vessel is <90% vs >90% | Beyond 5 years after bypass urgery |
| c) the proportion of completely occluded grafts where proximal stenosis of native vessel is <90% vs >90% | Beyond 5 years after bypass urgery |
| d) proportion of study grafts with string sign | Beyond 5 years after bypass urgery |
Countries
Canada, New Zealand
Outcome results
None listed