Relevance of SYNTAX score for assessment of saphenous vein graft failure after coronary artery bypass grafting

OBJECTIVE: To identify risk factors of saphenous vein graft (SVG) failure and to investigate the utility of anatomical SYNTAX score (SS) and SYNTAX score II (SS-II) in predicting SVG failure. METHODS: A total of 598 patients who underwent angiography for clinical reasons after coronary artery bypass grafting (CABG) were included. Baseline data and factors related to SVG failure were analyzed at the patient and graft levels. Patients were divided in tertiles by anatomical SS and in three groups by SS-II revascularization recommendation, and SVG patency was analyzed across these groups. RESULTS: Patency rates were similar in all SS-stratified and SS-II recommendation groups within 1, 5, and 10 years after CABG. At the patient level, fasting blood glucose (FBG) level <7.0 mmol/L was less common in SVG failure (68.0% vs. 76.2%). At the graft level, patients with SVG failure tended to have angiography later (4.0 years vs. 3.0 years), poorer FBG control (FBG <7.0 mmol/L: 68.2% vs. 74.7%), and more grafts anastomosed to the right coronary system (59.2% vs. 47.4%). Longer time interval after CABG was related to SVG failure both at the patient and graft levels, and odds ratio (OR)/P values (OR/P) were 1.282/0.029 and 1.384/0.016, respectively. Using independent graft and grafting to the right artery system as risk factors at the graft level, OR/Ps were 3.094/0.000 and 2.524/0.000, respectively. CONCLUSIONS: Longer time interval after CABG, independent grafts, and grafting to the right artery system are associated with SVG failure. Anatomical SS or SS-II may not be reasonable tools for predicting SVG failure.