Patients with prior coronary artery bypass graft surgery (CABG) are at increased risk for recurrent cardiovascular ischaemic events. Advances in management have improved prognosis of patients with acute coronary syndrome (ACS), yet it is not known whether similar trends exist in patients with prior CABG.Examine temporal trends in the prevalence, treatment and clinical outcomes of patients with prior CABG admitted with ACS.Time-dependent analysis of patients with or without prior CABG admitted with an ACS who enrolled in the ACS Israeli Surveys between 2000 and 2016. Surveys were divided into early (2000-2008) and late (2010-2016) time periods. Outcomes included 30 days major adverse cardiac events (30d MACE) (death, myocardial infarction, stroke, unstable angina, stent thrombosis, urgent revascularisation) and 1-year mortality.Among 15 152 patients with ACS, 1506 (9.9%) had a prior CABG. Patients with prior CABG were older (69 vs 63 years), had more comorbidities and presented more with non-ST elevation-ACS (82% vs 51%). Between time periods, utilisation of antiplatelets, statins and percutaneous interventions significantly increased in both groups (p<0.001 for each). The rate of 30d MACE decreased in patients with (19.1%-12.4%, p=0.001) and without (17.4%-9.5%, p<0.001) prior CABG. However, 1-year mortality decreased only in patients without prior CABG (10.5% vs 7.4%, p<0.001) and remained unchanged in patients with prior CABG. Results were consistent after propensity matching.Despite an improvement in the management and prognosis of patients with ACS in the last decade, the rate of 1-year mortality of patients with prior CABG admitted with an ACS remained unchanged.