To analyse the profile and clinical outcomes of patients with pre-existing coronary artery disease(CAD) treated with primary PCI for STEMI at The Canberra Hospital All 127 patients undergoing primary PCI for acute STEMI at The Canberra Hospital in 2019 were studied. Procedural and clinical outcomes were collected. 29 (22%) patients had pre-existing CAD. The profile of the latter group compared to de novo CAD patients in brackets were: mean age 61(64)yrs, male% 86(86): prior PCI 62%, prior CABG 7%,treated hypertension% 62(40), treated hyperlipidaemia% 59(40), treated diabetes% 20(14), smoker% 26(27) mean weight 88(83)kg, mean BMI 29(28) mean TC 4.0(4..6), mean LDL 2.0(2.8), mean TG 2.0(1.5), mean creatinine 90(79) umol/l, mean eGFR 71(80), mean peak troponin I 39121(32027)ng/l, mean peak CK 1984(1494)u/l, median cath lab door to wire time 25 (24)mins, median hospital door to balloon time 49.5(44.5)mins, RCA culprit 41(51)%, LAD culprit 34(36)%, mean length of stay 4(3) days, ambulance activation% 41(39), Inhospital mortality% 3.4(3.1). Patient with pre-existing CAD undergoing primary PCI for STEMI appeared to have different profile and clinical outcomes to de novo patients.