Abstract 21304: Vein graft loss following CABG — A 2-year angiography follow-up with Optical Coherence Tomography
Background: Coronary bypass surgery (CABG) is a well-established and effective strategy for coronary revascularisation but there remains a significant vein graft attrition rate. To understand the impact of vein graft biology on clinical outcome we compared angiographic appearances including optical coherence tomography (OCT) at 2 years post-operation to vascular responses at time of operation and post-operative clinical course.
Methods: 42 patients underwent off-pump CABG using saphenous vein (SVG) and left or right internal mammary artery grafts (LIMA/RIMA) as appropriate. Samples of LIMA and/or saphenous vein grafts were harvested during CABG and used to measure superoxide levels ex-vivo using lucigenin-enhanced chemiluminescence. Patients underwent elective diagnostic angiographic follow-up (median 985 days IQR 916–1028) 15 patients underwent OCT of a saphenous vein graft.
Results: At follow-up patency rates were 29/33 LIMA, 17/22 RIMA, 39/67 SVG, 2/6 radial. There was an association between SVG patency rates and hospital stay (N=35, p=0.011) and with high-dependency stay (N=35, p=0.048). The intimal cross sectional area measured by OCT of patent vein grafts was related to superoxide levels measured from the saphenous vein graft at the time of harvest (N=6, p=0.039). Patent vein grafts had a smooth neointima with little evidence of intimal calcification or lipid plaque formation. Discussion: Vein graft patency at two years associates with peri-operative factors, which suggests many occlusions occur in the immediate post-operative period. OCT at 2–3 years supports this assertion showing early formation of a smooth neointima in patent grafts but with minimal calcification or lipid plaque formation to indicate accelerated atherosclerosis.
- © 2010 by American Heart Association, Inc.