BACKGROUND: We evaluated the association between invasive and non-invasive management and hospital and 6-month outcomes in patients with a prior coronary artery bypass graft (CABG) who experienced an acute coronary syndrome.

METHODS: Data were analysed from patients with a prior CABG who developed an acute coronary syndrome and were enrolled in the Global Registry of Acute Coronary Events. From 44,991 patients included in the study, 3853 fulfilled the inclusion criteria. Of these, 3356 received non-invasive treatment approaches while 497 underwent invasive treatment (percutaneous coronary intervention [PCI] within 48 h of admission).

RESULTS: The primary composite endpoint of death, non-fatal myocardial infarction, and recurrent ischaemia during hospitalization was similar in patients in the non-invasive and invasive groups (31% vs 30%, respectively; P=0.53). The rates of hospital mortality (non-invasive 3.4% vs invasive 3.2%) and non-fatal myocardial infarction (3.4% vs 5.1%, respectively) were similar. At 6-month follow-up, the mortality rate was 6.5% in the non-invasive group vs 3.4% in the invasive group (P<0.02); the combined endpoint of death or myocardial infarction was lower in the invasive group (P<0.01). Multivariable analysis showed that, at 6-month follow-up, the combined endpoint of death, non-fatal myocardial infarction, and rehospitalization for heart disease was similar (P=0.10). A greater proportion of patients in the invasive group required unscheduled diagnostic and therapeutic invasive procedures compared with those in the non-invasive group (angiography 15.4% vs 8.1%; PCI 10% vs 5.0%; both P<0.001).

CONCLUSIONS: The results from this observational study show no statistically significant differences in hospital outcomes between acute coronary syndrome patients with a prior CABG who undergo invasive or non-invasive treatment. Invasively treated patients experienced higher rates of readmission and additional cardiac procedures than non-invasively treated patients but a lower incidence of cardiovascular complications at 6 months.