Thirty-day outcomes in Indigenous Australians following coronary artery bypass grafting

BACKGROUND Indigenous Australians have higher rates of cardiovascular disease and comorbidities compared to their non-indigenous counterparts. AIMS We sought to evaluate whether indigenous status per se portends a worse prognosis following isolated coronary artery bypass grafting (CABG). METHODS The outcomes of 778 Indigenous Australians (55 ± 10 years; 32% female) enrolled in the Australian and New Zealand Society of Cardiac and Thoracic Surgeons registry were compared to 36 124 non-Indigenous Australians (66 ± 10 years; 21% female) following isolated CABG. In a secondary analysis, patients were propensity-matched by age, sex, renal function, diabetes and ejection fraction (778 individuals in each group). RESULTS Indigenous Australians were younger and more likely to be female and current smokers and to have diabetes, hypertension, renal impairment, heart failure and previous CABG (all P < 0.04). Indigenous patients had fewer bypasses with arterial conduits (including less internal mammary artery use) and a higher number of distal vein anastomoses (P < 0.001). Postoperative bleeding rates were higher in indigenous patients (P = 0.001). However, in-hospital and 30-day all-cause mortality and rates of 30-day readmission were similar between both groups, although cardiac mortality was higher in the indigenous cohort (1.5% vs 0.8%, P = 0.02). With propensity-matching, rates of postoperative complications were similar among the two groups, with the exception of bleeding, which remained higher in Indigenous Australians (P = 0.03). CONCLUSIONS Despite procedural differences and higher rates of baseline comorbidities, Indigenous Australians do not have worse short-term outcomes following isolated CABG. Given the higher rates of baseline comorbidities and lower rates of arterial conduit use, it will be essential to determine long-term outcomes.