40 Saphenous vein graft radio-opaque markers and femoral access reduce contrast use in coronary angiography and graft studies

Background Saphenous vein grafts (SVG) are often employed for bypass in addition to internal mammary arteries during CABG operations. Despite the improvement in surgical technique most post CABG patients will require additional coronary artery catheterization in their lifetimes. Radio-opaque markers for SVGs are safe and easy to implant during the CABG operation. The markers were found to have no impact on long term graft patency. However, these markers should make repeat coronary angiography and graft studies easier and allow these procedures to be performed with less contrast thereby reducing the risk of contrast induced nephropathy. Methods We systematically reviewed consecutive diagnostic coronary angiograms of all patients with previous CABG at a single large Canadian interventional centre. Basic demographic and clinical data, access site, number of grafts, operator, and amount of contrast used were recorded for analysis. Predictors of amount of contrast used were identified using multiple regression analysis with stepwise elimination of factors utilizing SPSS software. Results Between Jan 2016 and May 2019, 746 diagnostic coronary angiograms and graft studies were performed. 328 cases were excluded because the patients had additional procedures done in the same setting. Mean age of patients was 71 (9) years, 12 % were female. 41% of patients had a clip inserted at the time of their bypass surgery. 15% of patients had a single vein graft used at the time of surgery, 43% had two vein grafts and 42% of patients three or more grafts. 56 % of the procedures were performed via the femoral route. Independent predictors of contrast volume used were access site (187 (64) ml for radial vs 170 (60) ml for femoral), number of grafts used (+ 24 ml per additional graft) and use of radio-opaque markers during CV surgery (166 (54) ml with surgical clips versus 186 (66) ml without clips). Age, gender and operator were not predictive of the amount of contrast used. Conclusions Positioning graft markers at the time of CV surgery can significantly reduce the contrast requirement for subsequent cardiac catheterisation. Even in a high volume radial centre further reductions of contrast use can be achieved by using femoral rather than radial access. Conflict of Interest None