OBJECTIVES: Coronary graft failure (CGF) may occur early after coronary bypass graft surgery (CABG). The study aimed to identify clinical and perioperative risk factors and to evaluate the long-term clinical impact of symptomatic early CGF. METHODS: Patients who underwent clinically indicated coronary angiography (CAG) prior to post-CABG discharge between 2012 and 2022 were included. Symptomatic early CGF was defined as a dysfunctional coronary graft, evaluated on clinically indicated CAG, caused by stenosis of the proximal or distal anastomosis or bypass conduit, bypass occlusion, thrombosis, reduced flow (TIMI <
1) and kinking/tenting. Patients were divided into symptomatic early CGF and non-early CGF groups. Kaplan-Meier and multivariate analysis estimated cumulative survival free of major adverse cardiovascular events (MACE: death, myocardial infarction and revascularisation) up to 5 years' follow-up and identified predictors of symptomatic early CGF. RESULTS: A total of 92 patients (79% male, 66.1 ± 10 years old) were included, of whom 55 (59.8%) had symptomatic early CGF. Baseline characteristics, surgical parameters and post-surgical parameters potentially indicative of ischaemia were comparable between groups. Patients with symptomatic early CGF had a significantly lower MACE rate over a median follow-up period of 33 months (p = 0.023). Venous graft integration (p = 0.005), Y‑graft configuration (p = 0.002) and prolonged inotropic support (p = 0.032) were associated with symptomatic early CGF. CONCLUSIONS: Symptomatic early CGF was observed in the majority of post-CABG patients undergoing clinically indicated CAG prior to discharge. Patients with symptomatic early CGF exhibited higher MACE rates over a median follow-up period of 33 months. Venous graft integration, Y‑graft configuration and prolonged use of inotropic agents were associated with symptomatic early CGF. However, these clinical findings should be interpreted with caution.