Objective: To describe baseline characteristics, operative events and late mortality among Indigenous Australians undergoing cardiac surgery.
Design, setting and participants: Prospective study of consecutive patients undergoing cardiac surgery at Flinders Medical Centre in Adelaide between January 2000 and December 2005.
Main outcome measures: Operative (30-day) mortality and late mortality after cardiac surgery.
Results: Of 2635 patients undergoing cardiac surgery, 283 (10.7%) were Indigenous. Indigenous patients were substantially younger than non-Indigenous patients (mean, 47 [SD, 14] years v 65 [SD, 12] years; P = 0.001) and were more likely to have diabetes (39.6% v 27.3%; P = 0.001), renal dysfunction (3.2% v 1.2%; P = 0.009), and valvular surgery (53.0% v 23.1%; P < 0.001). There was a non-significant trend toward excess operative mortality in Indigenous patients (Indigenous 2.5% v non-Indigenous 1.3%; hazard ratio [HR], 1.67 [95% CI, 0.74-3.75]). But in the under-55-years age cohort, the difference between the two groups was highly significant (Indigenous 3.3% v non-Indigenous 0.4%; HR, 7.99 [95% CI, 1.66-38.50]), even after adjustment for euroSCORE (the European System for Cardiac Operative Risk Evaluation). Survival at 1 and 5 years was 94.0% and 80.6%, respectively, for Indigenous patients compared with 96.7% and 87.7%, respectively, for non-Indigenous patients. There was an excess in euroSCORE-adjusted mortality in the Indigenous cohort overall (HR, 1.46 [95% CI, 1.03-2.07]) that strengthened when restricted to the under-55-years cohort (HR, 6.9 [95% CI, 1.42-33.5]).
Conclusion: Indigenous Australians present for cardiac surgery nearly 20 years earlier than non-Indigenous Australians and experience excess age-stratified operative and late mortality.