Graft Patency Between the Radial Artery and the No-touch Saphenous Vein in Coronary Artery Bypass Grafting Study (GRAFT-CAB Study)

CABG is still the treatment of choice for ischemic heart disease. However, restenosis or occlusion may occur to graft vessels, leading to postoperative myocardial ischemia and subsequent clinical events. Long-term angiographic follow-up demonstrated that vein graft restenosis and occlusion are common among those receiving CABG, with a vein graft patency of less than 50% at 15 years postoperatively.

A novel approach to harvesting the vein is called "No-touch" technique (NT), which can avoid mechanical damage to the vein wall. Previous studies showed that No-touch saphenous vein grafts (NT-SVG) has a 96.3% postoperative graft patency rate at 12 months, compared to 93.5% of conventional saphenous vein grafts (con-SVGs). Thus, the No-touch technique can significantly reduce postoperative graft occlusion. Radial artery(RA) as an arterial material for CABG surgery has a better long-term patency than con-SVG, up to 83% at 10 years. Using radial artery as the second graft for CABG may provide additional clinical benefit. However, the risk of perioperative vasospasm and graft occlusion due to competitive blood flow limit the using of radial artery. Therefore, only the No-touch vein and the radial artery can improve the graft patency. Only one randomized clinical trial(RCT) compared the RA and NT-vein, and this study is limited by irregular post-operative management and small sample size from single center.

This prospective single-center study aims to compare the short-term and long-term graft patency between the No-touch vein and the radial artery. This study will consecutively enroll at least 774 patients undergoing isolated on-pump/off-pump CABG. After obtaining informed written consent, participants will be randomly allocated to either the No-touch or the radial artery group. At baseline, participants will be interviewed to collect detailed information about on demographics, socioeconomic status, cardiovascular risk factors, clinical characteristics, treatments, in-hospital outcomes, general and disease-specific quality of life, function and mental status. During the follow-ups, the investigators will collect information about clinical outcomes events, long-term treatments, function, quality of life, symptoms, and medical care during the recovery period. All participants will be invited for 64-slice multi-slice computed tomography angiography (MSCTA) analysis at 3 months and 12 months post-operatively for graft patency evaluation.

The data adjudicators and computed tomography(CT) reviewers will be blinded to the study. Due to the nature of this study, the operating surgeons, anesthetists and other operative room staff will not be blind in this study. Owing to the use of radial artery need approved by the participant, so participants will also not be blind in this study,

By comparing the short-term and long-term graft patency between the No-touch vein and radial artery groups, this study will contribute major evidence of the possible superiority between two different grafts, so as to improve patient outcomes after CABG surgery.